Applied Science and Engineering Progress
Applied Science and Engineering Progress (ISSN: 2672-9156, Online-ISSN: 2673-0421) is an international, double-blind peer-reviewed by at least two independent reviewers, open access scientific journal, free of charge, published by King Mongkut’s University of Technology North Bangkok (KMUTNB) since 2008. Applied Science and Engineering Progress published original research articles, reviews, and editorial corner in areas of applied science and engineering. The journal also publishes high quality and peer-reviewed papers presented at conference hosted/co-hosted by KMUTNB to expand the research connection between scientists and engineers. Applied Science and Engineering Progress also aims to introduce research progress of applied science and achievements of engineering development to the world community by demonstrating the significance of research investigations and demonstrations. Journal Abbreviation: Appl. Sci. Eng. Prog. Language: English Publication Fee: 200 USD (For manuscripts submitted after Oct. 1, 2025) Issues per Year: 4 Issues (Jan-March, April-June, July-September, and October-December) Journal Statistics Average days to acceptance: 60 days Average days to first decision: 4 days Acceptance rate in 2025: 10.2% SCOPUS Citations/article during 2019-2025 is 7.2 (update 30 Dec. 2025)
Development of Core-Shell Alginate-Gelatin Capsules for Stabilization of Kratom Alkaloids via Coaxial Electrospray
Kratom (Mitragyna speciosa Korth.) contains bioactive alkaloids, particularly mitragynine, which exhibit poor aqueous solubility and instability under light and thermal conditions, limiting their practical applications. This study presents a process-oriented approach for stabilizing kratom extract via core–shell encapsulation using a coaxial electrospray technique. Gelatin and sodium alginate were employed as core and shell materials, respectively. The effects of sodium alginate concentration (1.0–2.0 % w/v) and applied voltage (0–2,500 V) on capsule morphology and size distribution were systematically investigated. Optimal conditions (2.0 % w/v alginate, 1,500 V) yielded uniform spherical capsules with an average diameter of 4.29 ± 0.07 mm. Structural characterization using FT-IR confirmed successful encapsulation, while UV–Vis and GC–MS analyses verified the presence and quantified the content of mitragynine. Stability studies demonstrated that capsules maintained structural integrity under neutral pH and varied temperature conditions over 14 days. Cytotoxicity evaluation using Vero cells indicated high cell viability (> 80 %), confirming biocompatibility. The results highlight the feasibility of coaxial electrospray as a scalable and controllable encapsulation process for bioactive compounds in food and pharmaceutical engineering applications.
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Thermo-mechanical Creep Performance of Kevlar and Woven Glass Fiber-based Composites Through Experimental Techniques and Viscoelastic Modelling
Fiber-reinforced composites play a significant role in various temperature-dependent engineering applications. Hybrid composites, incorporating reinforcements such as glass, carbon, and Kevlar fibers, significantly improve the mechanical properties of polymer composites. The present work aims to study the thermo-mechanical creep behaviour of Kevlar- and woven glass-fiber-reinforced epoxy hybrid (KGFRH) composites through experimental testing and viscoelastic modelling. The composites were fabricated using a compression moulding process. The tensile creep behaviour of the hybrid composites was investigated by varying the applied loads to 50, 75, and 100 kg and the temperatures to 100, 120, and 140°C. The creep strain versus time data were recorded for all samples. The creep strain gradually increased with increasing load and temperature. At lower load and temperature conditions, the creep curve showed better performance because all three stages of creep failure were observed, whereas at higher load and temperature conditions, only the primary and secondary stages were noted. The combination of a 50 kg load and 100°C temperature showed the best results. Viscoelastic numerical models, including Burger’s model and the Norton model, were used to predict the elastic modulus, coefficients, and curve-fitting values. Kevlar/glass–epoxy composites with improved thermo-mechanical behaviour can be utilized in lightweight and protective applications.
Edge-Enabled Digital Twin for Autonomous Low-Latency Dissolved Oxygen Control for Partial Nitritation-Anammox Reactor
Anammox reactors are high-efficiency, energy-saving nitrogen treatment technologies, yet their process stability is highly sensitive to fluctuations in dissolved oxygen (DO). Most wastewater treatment Internet of Things systems remain limited to cloud-based monitoring without low-latency adaptive control or dynamic process representation. This study develops an edge-enabled digital twin for real-time multi-parameter monitoring and closed-loop DO control a partial nitritation-anammox reactor. The system employs an ESP32-S3 as an edge computing node for local acquisition, and monitoring of DO, ORP, pH, water temperature, TDS, room temperature, and humidity, while executing a process model dynamically synchronized with the physical reactor. Field implementation demonstrates stable operation with water temperature of 27.4 ± 0.42 °C, room temperature of 30.8 ± 0.6 °C, relative humidity of 55.2 ± 2.1%, pH of 6.21 ± 0.11, ORP of +295 ± 18 mV, and TDS of 82.6 ± 3.4 ppm. DO was maintained at a setpoint of 0.50 mg/L with ±0.03 mg/L deviation, 0.024 mg/L mean absolute error, 5.2% maximum overshoot, and 20–28 s recovery time. The edge-based control latency of 0.43 s ensures stable aeration regulation independent of cloud connectivity. The novelty lies in integrating a digital twin directly at the edge to enable autonomous DO regulation, enhancing process stability while reducing aeration energy consumption by up to 26% compared with conventional systems.
Applied Surveillance Technologies for Mosquito Identification Across the Life Cycle: A Comparative Review
Reliable mosquito identification is essential for surveillance systems that support vector monitoring, risk assessment, and targeted intervention. However, conventional morphology-based identification remains labor-intensive, expertise-dependent, and difficult to scale for large monitoring programs. Advances in molecular diagnostics, imaging technologies, and artificial intelligence have enabled faster and more objective alternatives across the mosquito life cycle. This review presents a stage-aware comparative synthesis of mosquito identification methods for eggs, larvae, pupae, and adults, covering classical morphology, molecular and proteomic assays, geometric morphometrics, deep learning-based image analysis, acoustic sensing, and IoT-enabled smart traps. Structured as a narrative comparative review, the article evaluates these approaches in terms of diagnostic role, scalability, cost, infrastructure requirements, and field deployability. The analysis shows that each life stage supports a distinct surveillance function and that no single method is optimal across the full mosquito life cycle. Effective surveillance, therefore, requires tiered workflows that combine low-cost collection, automated screening, and selective confirmatory analysis according to operational needs.
Machine Learning-Based Forecasting of Compressive Strength for Ambient-Cured GGBS Geopolymer Concrete
Geopolymer concrete is gaining attention as a sustainable alternative to Ordinary Portland Cement (OPC) concrete because of its lower carbon emissions and improved durability. However, predicting the compressive strength of Ground Granulated Blast Furnace Slag (GGBS)-based geopolymer concrete under ambient curing remains difficult due to the complex and non-linear effects of mix proportions and curing parameters. This study addresses that problem by developing machine learning models to predict the compressive strength of M25 grade GGBS-based geopolymer concrete using a dataset of 80 laboratory-tested samples, supplemented with published data. The input variables included NaOH molarity, aggregate proportions, activator-to-binder ratio, additional water content, activator composition, and curing age. A multi-layer feed-forward Artificial Neural Network (ANN) and Linear Regression (LR) model were developed in Python after normalizing all inputs using min-max scaling. Model performance was evaluated using Mean Absolute Error (MAE), coefficient of determination (R²), and Root Mean Squared Error (RMSE). The ANN model outperformed LR, achieving an MAE of 2.15 N/mm², R² of 0.951, and RMSE of 2.89 N/mm², compared with an MAE of 3.24 N/mm², R² of 0.923, and RMSE of 4.18 N/mm² for LR. Sensitivity analysis showed that curing age, NaOH molarity, and activator-to-binder ratio were the most influential factors governing strength development. The results confirm that ANN-based prediction can accurately estimate compressive strength while reducing experimental effort and supporting sustainable mix design.
Investigation of oxygen permeation behavior across BYS-coated LSCF Multi-Channel Hollow Fiber Membrane using N2O as an Oxygen Source
A 6-channel LSCF hollow fiber membrane was successfully fabricated and subsequently modified via an in situ coating of BYS to enhance its oxygen transport performance. The BYS coating formed a uniform, thin film along the inner surface of the LSCF membrane, increasing surface roughness and active site density for oxygen exchange without compromising mechanical integrity. Oxygen permeation experiments were carried out using both air and N2O as oxygen sources. Under air feed conditions, the BYS-modified membrane exhibited a markedly higher oxygen permeation flux than the pristine LSaCF membrane, confirming that the BYS layer effectively promoted surface exchange kinetics. When N2O was employed, the oxygen permeation rate was strongly dependent on both gas flow rate and operating temperature. Under optimized conditions (50 mL/min of N2O feed and 100 mL/min of Ar sweep gas), the BYS-coated LSCF membrane achieved an oxygen permeation flux of 2.0 mL/mincm2 with 80% N2O conversion at 980 °C. These findings demonstrate the beneficial relationship between N2O decomposition and in situ oxygen removal, establishing the BYS-coated LSCF hollow fiber as a highly efficient oxygen transport platform and a promising, sustainable pathway for greenhouse gas mitigation.
Metallurgical Analysis and Economic Feasibility of Thermite Welding Applied to Railway Rail Surface Repair
This study developed welding molds and investigated the metallurgical behavior of thermite repair welds for R260 grade railway rail surface repair using a Mixture Design approach, together with an economic feasibility analysis in comparison with conventional welding. Mold compressive strength increased significantly with slica sand content (p-value < 0.01), while graphite and water exerted negative effects on strength (p-value < 0.05) and increased porosity through a significant interaction effect. With thermal resistance ranged from 1,430 to 1,570 °C, Runs 1, 2, and 6 provided the best balance of properties, with all models demonstrating high accuracy (R² > 0.90). Mold Type 1 produced rough weld surfaces with slag residue and numerous pores, while Mold Type 2 produced smoother surfaces with minimal porosity and no cracks, neither mold type exhibited macro-level cracking. SEM analysis revealed that the base metal consisted of lamellar pearlite (α + Fe₃C). Mold Type 1 produced coarse pearlite with grain boundary ferrite and significant pore accumulation, whereas Mold Type 2 yielded fine, uniform pearlite with virtually no porosity. EDX analysis indicated micro-segregation in Mold Type 1 welds, suggesting structural non-uniformity and potential stress concentration sites, while Mold Type 2 welds exhibited more uniform elemental distribution, which may promote fine pearlite formation and defect reduction. Economic analysis showed that thermite welding costs 290 THB per joint versus 960 THB for SMAW (Cost Ratio, CR = 3.31; cost savings of 69.8%), and requires only 15–20 minutes compared to 90 minutes (Time Reduction Ratio, TRR = 4.5), suggesting promising economic feasibility under the conditions evaluated. The hardness test results showed that Mold Type 2 provided uniform hardness values, with HAZ hardness ranging from 360–410 HV and weld zone hardness ranging from 320–360 HV. These results were consistent with the SEM and EDX analyses, which revealed a fine pearlitic microstructure and homogeneous elemental distribution, indicating that Mold Type 2 was more suitable for railway rail surface repair than Mold Type 1.
Development and Characterization of Virgin Coconut Oil Nanoemulsions Stabilized with Soy Lecithin and Tween 20
Virgin coconut oil has attracted considerable attention due to its health-promoting properties and its potential applications in biodegradable coatings, natural preservatives, and nutraceutical delivery systems, particularly in nanoemulsion form. This study investigated the droplet size distribution as well as the physicochemical and functional properties of virgin coconut oil nanoemulsions produced by ultrasonication. Nanoemulsions stabilized with Tween 20 exhibited mean droplet sizes ranging from 327.6 ± 0.9 to 367.5 ± 0.4 nm, whereas those stabilized with soy lecithin ranged from 292.4 ± 1.6 to 576.7 ± 3.3 nm. All formulations showed polydispersity index values below 0.3, indicating relatively uniform droplet size distributions. Peroxide and acid values increased during storage, suggesting progressive lipid oxidation and hydrolysis. Fatty acid analysis using Gas Chromatography-Flame Ionization Detector (GC-FID) revealed that lauric acid is the predominant component (7.81 g/100 g fat) in the nanoemulsion system. Stability tests conducted at room temperature demonstrated that soy lecithin provided superior physical stability across most formulation ratios. These findings provide insights into the selection of natural emulsifiers for improving the stability of virgin coconut oil-based nanoemulsions intended for functional food and nutraceutical applications.
Nanotechnology Applications in Aquaponics: Feed Engineering, Nutrient Cycling Efficiency, and System Performance Optimization
Aquaponics integrates aquaculture and hydroponics within a recirculating system; however, achieving stable nutrient cycling and optimal system performance remains a major challenge due to limitations in nitrification efficiency, nutrient availability, and hydraulic performance. This review evaluates the role of nanotechnology as an engineering strategy to enhance nutrient transformation, improve feed utilization, and optimize overall system performance in aquaponic systems, with a particular focus on tilapia–lettuce production. Nano-enhanced feed formulations, including nano-silica and micronutrients, are examined for their ability to improve feed conversion efficiency, enhance nutrient retention, and reduce Total Ammonia Nitrogen (TAN) loading to biofilters. In parallel, nanostructured biofilter media are assessed for their capacity to increase specific surface area, promote biofilm development, and enhance nitrification kinetics. At the plant interface, nanofertilizers are evaluated for their role in improving micronutrient availability and nutrient uptake efficiency. This review adopts an engineering perspective by linking feed inputs, microbial processes, and plant uptake through mass balance and transport mechanisms. While nanotechnology offers significant potential to improve Nitrogen Use Efficiency (NUE) and system stability, concerns regarding nanoparticle toxicity, bioaccumulation, and long-term environmental impacts remain critical challenges. Future research should prioritize quantitative validation, system-scale integration, and safety assessments to support the sustainable implementation of nanotechnology in precision agriculture.
Morphological Transformation of Self-Assembled Platinum Nanodots on Isopropanol-Modified Quartz Substrate via Thermal Dewetting
The controlled fabrication of platinum (Pt) nanodots on quartz substrates has attracted considerable attention for advanced applications in plasmonics, biosensing, catalysis, and nanoelectronic devices. In this study, the morphological transformation of thermally dewetted Pt thin films deposited on untreated and isopropanol (IPA)-modified quartz substrates was systematically investigated. Pt thin films with a thickness of approximately 10 nm were deposited using a sputter coating technique and subsequently annealed at temperatures ranging from 400 °C to 700 °C. The thermal dewetting behavior and morphological evolution of Pt nanostructures were systematically examined through hot stage-assisted in situ thermal annealing integrated with field-emission scanning electron microscopy (FE-SEM), combined with ImageJ-based quantitative surface coverage analysis. The results demonstrated that annealing temperature and substrate surface condition strongly influenced the dewetting behavior and final morphology of the Pt nanostructures. At lower annealing temperatures, the Pt films exhibited limited atomic diffusion and irregular fragmented structures, whereas higher temperatures promoted film breakup and the formation of isolated Pt nanodots. A significant difference in morphological evolution was observed between untreated and IPA-treated substrates. The untreated substrate retained partially interconnected Pt domains even at high annealing temperatures, indicating incomplete dewetting behavior. In contrast, the IPA-treated substrate facilitated the formation of smaller, more uniformly distributed, and well-separated Pt nanodots with reduced surface coverage, suggesting enhanced thermal dewetting and improved nanoparticle uniformity. In addition, absorbance spectra measurements revealed morphology-dependent optical responses associated with variations in Pt nanostructure size and particle distribution. The Pt nanodots formed on the IPA-treated substrate exhibited a higher, steeper absorbance peak than those formed on the untreated substrate, indicating improved nanoparticle uniformity and enhanced morphology-dependent optical interactions after thermal dewetting. The experimental results in this study clearly demonstrate the effect of IPA surface treatment on the morphological transformation and dewetting behavior of Pt thin films.
Advancing Sustainable University Technoparks through Smart Infrastructure and Green Campus Development: A Review of SDG-Oriented Strategies
Evaluating the Physical and Mechanical Properties of PET and Crumb Rubber Compounds for Tire Tread Applications
In the present study, two types of polymer materials are utilized: PET and crumb rubber. The PET material is used in the production of water bottles and crumb rubber (produced from recycled tires) for manufacturing the Tread part for passenger cars. The study utilizes a master batch compound prepared by the Babylon Tires Factory in Iraq to prepare laboratory final compounds using various experimental techniques. Extensive tests were conducted on rubber samples, including vulcanization process time (T90 and Ts2), specific gravity, hardness test, viscosity test, tensile strength test, torque test, abrasion test, and fatigue test. According to the test results, two compounds that confirmed to the company's standards were selected. Twelve samples of compounds are prepared and divided into two groups (A and B), each containing six compounds. In group (A), the amount of PET is stabilized with the rest of the additives added and the amount of crumb rubber. The group (B) amount of crumb rubber is stabilized with the rest of the other additions and the amount of PET. The test results of the compounds are compared with the standard specifications of Dunlop technology used in the rubber and tire industry. The results show that sample no. (2) From group (B) is the best sample for the abrasion value while maintaining the result of properties within the limits specified. The PET and crumb rubber amount should not exceed (1.3/2.5) pphr, in which the maximum tensile strength and hardness can be obtained with minimum cure characterization time. By tailoring PET-rubber ratios, the research enhances mechanical strength, thermal stability, and durability while promoting the recycling of plastic and rubber waste.
Influence of Muscle Contraction on Pedestrian Injury in Pickup-Truck Collision
Pedestrian safety remains a major public health concern. Although numerical human body models are widely used in the automotive industry, most lack active muscle representation, a factor that can influence body kinematics during low-speed collisions. This study investigates how skeletal muscle activation impacts pedestrian kinematics and injury. A skeletal muscle model combining 3D tetrahedral and 1D line elements was developed. Passive behavior was modeled using the Ogden model, while active behavior was based on the Hill-type muscle model. The model was validated against published data and integrated into a finite element pedestrian model. Four levels of muscle activation were applied to examine their effects on kinematics and injury metrics. Active muscle significantly influences pedestrian response during collisions. Models with active muscle demonstrated higher contact forces, head injury criteria, lower extremity bending moments, and knee shear distance but lower knee bending angles. For instance, at 20 km/h, comparing passive to fully active models revealed a significant 179% increase in Head Injury Criterion (HIC), a 10% decrease in knee bending angle, and a 7.7% increase in shear distance. Varying activation levels had a minimal effect on lower extremity forces and moments but influenced HIC and knee metrics. The same trends were observed at higher impact speeds. These results underscore that including active muscle behavior is essential for accurate pedestrian injury prediction in low-speed collisions.
Rigid Polyurethane Foam Reinforced with Microfibrillated Cellulose from Oil Palm Empty Fruit Bunches as Efficient Thermal Insulation
There is increasing interest in enhancing the thermal insulation of rigid polyurethane foam (RPUF) through a sustainable approach. This work presents the utilization of micro-sized biobased fillers, microfibrillated cellulose (MFC) derived from oil palm empty fruit bunches (EFB) waste, to improve the properties of RPUF composite as a potential insulation material. The inclusion of MFCEFB fillers at varied compositions (0.25–1 wt.%) in the RPUF composites demonstrated significant improvement of thermal insulation, as evidenced by their correlation with lower thermal conductivity, without compromising the mechanical properties compared to the control RPUF without MFCEFB. The results showed a decrease in the thermal conductivity of RPUF composite by 7.92% with the addition of 0.5 wt.% MFCEFB. The compressive strength also increased by 11.76% compared to the control RPUF. These enhancements were correlated to MFCEFB acting as a nucleating agent in the RPUF foaming process, where morphological analysis confirmed that the addition of MFCEFB resulted in smaller and more uniform cell sizes compared to the control RPUF. Fourier transform infra-red (FTIR) analysis revealed potential interactions between MFCEFB and polyurethane that could improve foam structural integrity. Moreover, the incorporation of MFCEFB at very low concentration had a negligible effect on the biodegradability compared to the RPUF control, demonstrating similar structural integrity to the control RPUF under natural environmental conditions, thereby ensuring the long-term durability of RPUF biocomposites.
Pectin-Aloe vera Gel Biopolymer Transdermal Patches for Prospective Limonene Delivery System: Characterization and in vitro Release Kinetics
Pectin-based transdermal systems suffer from inadequate mechanical properties and rapid biodegradation, limiting pharmaceutical applications. This study addresses these critical limitations through novel transdermal patches fabricated with varied pectin concentrations (7–11g) and Aloe vera (AV) gel extract (0–10% w/w) as a bioactive matrix for Citrus aurantifolia-derived limonene delivery. Patches were fabricated via solvent casting using pectin and AV gel, followed by characterization of physicochemical properties (swelling, moisture content, and biodegradation), surface morphology (SEM), and molecular interactions (FTIR). Mechanical properties were assessed by tensile testing and in vitro release studies were performed using a Franz diffusion cell with benzoylated dialysis membrane to evaluate release kinetics. Optimal formulations demonstrated a remarkable 7.39-fold tensile strength enhancement (6.070 ± 0.008 MPa), superior in vitro release kinetics, with 57.85 ± 0.60% initial burst release, and 94.61 ± 0.30% sustained delivery over 120 h. Korsmeyer-Peppas kinetics (n = 0.472) confirmed non-Fickian diffusion mechanisms. Economic viability was established (production cost: 2.5 USD/L; net profit: 2.8 USD/L), presenting a commercially feasible and biodegradable solution for pharmaceutical applications. Future investigations will focus on in vivo evaluation to confirm the efficacy, safety, and clinical applicability of the developed patches.
Average Run Length of Double Modified Exponentially Weighted Moving Average Control Chart by Numerical Integral Equation
Through the use of Numerical Integral Equation (NIE) techniques—specifically, the Gaussian, Midpoint, Trapezoidal, and Simpson's rules—and the Double Modified Exponentially Weighted Moving Average (DMEWMA) control chart, this study aims to investigate the Average Run Length (ARL) approximation. Assuming that process data follow continuous probability distributions, specifically the exponential and Weibull distributions, the analytical framework is developed. Additionally, a thorough performance comparison is conducted between the DMEWMA control chart and two well-known substitutes: the Exponentially Weighted Moving Average (EWMA) control chart and the Modified Exponentially Weighted Moving Average (MEWMA) control chart. This comparative analysis is based on two critical performance indicators: the out-of-control Average Run Length (ARL1) and computational efficiency, as quantified by CPU processing time. The empirical results demonstrate that all NIE-based methods produce ARL estimates that are statistically indistinguishable, affirming their mutual accuracy. Nonetheless, with respect to computational performance, the Midpoint and Trapezoidal rules exhibit superior efficiency, achieving reduced processing times. Furthermore, at all levels of shift magnitude, the DMEWMA control chart continuously outperforms the MEWMA and EWMA charts in terms of sensitivity to changes in the process mean. All things considered, the results of this study highlight the effectiveness and usefulness of using NIE techniques for ARL estimation in sophisticated statistical process control. The proposed methodology not only yields precise and computationally efficient results but also exhibits strong applicability to a wide array of real-world datasets, thereby reinforcing its potential as a robust and versatile tool for contemporary process monitoring.
Mitigation of Enteric Methane Emission from Ruminant by Bioactive Compounds of Rhodomyrtus tomentosa: In Silico and In Vitro Studies
The livestock sector significantly contributes to greenhouse gas emissions, primarily methane (CH4) from enteric fermentation in ruminants. Methanogenesis in ruminants is facilitated by hydrogenotrophic methanogens and the key enzyme, namely Methyl Coenzyme Reductase (MCR). This study explores the potential of bioactive compounds derived from Rhodomyrtus tomentosa as MCR enzyme inhibitors to mitigate methane emissions. Twelve bioactive compounds were selected for in silico molecular docking against the MCR enzyme. Docking results indicated Rhodomyrtone, Tomentodione E, and Myricetin had the highest binding affinities with binding affinities of -9.5, -8.7, and -8.3 kcal/mol, respectively, outperforming the natural substrate Coenzyme B. ADMET predictions confirmed the drug-likeness and safety profiles of these compounds. Rhodomyrtone was further subjected to molecular dynamics (MD) simulations, demonstrating stable interactions with MCR, indicated by consistent RMSD, RMSF, and Rg values. An in vitro gas production technique evaluated Rhodomyrtone's efficacy in reducing methane emissions, using doses of 0.125 and 0.25 µg/ml. Results showed a non-significant reduction of 10% in methane production, suggesting the need for optimized dosing. This study highlights rhodomyrtone as a promising anti-methanogen agent, with potential implications for reducing methane emissions from ruminants. Future research should focus on dose optimization and the exploration of synergistic effects with other anti-methanogenic compounds to maximize methane reduction.
Ultrasound-Assisted Liquid Antisolvent Method Enables Rapid Synthesis of Bioactive Nanocurcumin
Curcumin, a bioactive compound derived from turmeric, has significant pharmacological potential but suffers from poor aqueous solubility (<10 μg/mL) and low bioavailability. To overcome these limitations, this study introduces a one-step ultrasound-assisted liquid antisolvent (UALA) precipitation method, integrating simultaneous sonication during solvent–antisolvent mixing to promote rapid nucleation and suppress particle aggregation. The method reduced particle size from >1000 nm to 255 nm (76% reduction), accompanied by a decrease in crystallinity from 58.7% to 21% and a reduction in enthalpy of fusion from 442.61 to 28.57 kJ/mol (93% decrease), indicating partial amorphization. Dissolution was markedly enhanced, achieving 94.36% release within 60 min, compared with only 7.75% for raw curcumin. Antioxidant activity improved significantly, with IC₅₀ values decreasing from 15 mg/mL (without sonication) to <1 mg/mL after optimized sonication, representing more than a 15-fold increase in potency. Collectively, these findings demonstrate that the UALA method provides a sustainable, carrier-free, and efficient route to produce nanocurcumin with superior physicochemical and bioactive properties, suitable for advanced pharmaceutical applications.
Artificial Intelligence Meets Catalysis: A New Approach to Heavy Diesel Desulfurization Using Trimetallic Activated Carbon Catalyst in Central Oscillating Reactor
To meet the new strict environmental legislations about sulfur content in petroleum fuels and their harmful emissions for high quality fuels, deep desulfurization strategies, such as oxidation process, have become an interesting topic in the academic and industrial fields. Therefore, this work develops a new Trimetallic Activated Carbon (TAC) catalyst, which is synthesized by decorating activated carbon with magnetic-manganese active oxides and an alumina coating film, for continuous deep oxidative desulfurization (ODS). Furthermore, a novel central oscillating reactor (COR) is fabricated by developing central baskets, which are employed to pack catalyst particles for continuous oxidative desulfurization. This new design exhibits a practical solution for handling the solid catalytic materials in central basket baffles for continuous operation, compared to previous studies that utilized only a central baffle with dispersed catalyst particles in the reacting fluids through batch operation mode. Process efficiency is examined utilizing hydrogen peroxide oxidant under mild conditions: 1 atm, temperature (30–90) °C, liquid hour space velocity, LHSV (0.33–0.08) min-1, oscillation parameters (amplitude, A: 3–12 mm, and frequency, f = 0.5–2 Hz). Also, Support Vector Machine (SVM) model is examined as a new machine learning tool to predict the desulfurization model. ODS technology shows high performance through low oxidation time (12 min) by reducing sulfur in heavy diesel fuel from 8281 ppm to 294 ppm to achieve 96.45 % oxidation efficiency under 90 °C, LHSV = 0.08 min-1, A = 12 mm and f = 2 Hz. SVM model data performed excellent prediction at R2 of 0.9962, mean absolute error (MAE) of 0.0791, and mean squared error (MSE) of 0.0078. The SVM strategy results in a high-accuracy artificial intelligence model under minimal deviations between actual and predicted data. The new integrated COR-TAC system provides an efficient, practical approach to deep, cost-effective and eco-friendly oxidative desulfurization; it can be directly scaled up into the refining industry at the same process performance.
Shear Behavior of Ultra-High-Performance Concrete Shear Pockets with Large-sized Studs in Full-Depth Precast Concrete Bridge Deck under Push-off Tests
Full-Depth Precast Concrete (FDPC) bridge deck panel system has been widely used for highway construction due to its rapid construction and replacement process as well as cost effective. This system was used with a cluster of large size headed-stud shear connectors (31.8 mm diameter) for transferring composite actions between concrete decks and steel girders. For more effectiveness in composite actions and cracks controlling around a cluster of large-size studs, Ultra High-Performance Concrete (UHPC) with compressive strength of 120 MPa was utilized for shear pocket connection between the normal strength concrete (NSC) 50 MPa bridge deck panels and steel girders. Eight specimens were push-off evaluated with variable geometries and layouts of shear pockets (9-, 12- and 15-inches width), and variable numbers of clustered large-size studs (4, 6 and 8 studs). The results showed three stages of crack pattern from the flexure, shear, and failure behaviors. Concrete crushing at the FDPC interface propagated across the slab section was observed in all specimens, while the shear plane cut at the UHPC section was found in the specimen with 4 studs. The shear strength at failure was compared to the nominal shear resistance of the design equations, AASHTO LRFD and Eurocode 4, in terms of the failure load ratio. The compatible results were found in the specimens with 4 studs in a square shape pocket, while the others found fewer results from 3.6% to 9.4%. The specimens with more than 4 studs required a reduction factor of 0.8 for each stud pair increment to evaluate a suitable shear resistance capacity for this system.
Climacteric Respiration and Fatty and Amino Acids Drive Volatile Ester Biosynthesis in Monthong Durian Aril during Fruit Maturation
The distinctive flavor of durian fruit is increasingly characterized, yet the metabolic pathways during ripening are not fully understood. This study investigated the volatile dynamics in ripening Monthong durian, revealing clear correlations between ripening stages and aroma compound production. Fruit ethylene production peaked one day after the first climacteric peak, initiating the second climacteric peak, pulp softening, and ester and sulfur-containing volatile emission. Ethanethiol, ethyl-2-methyl butanoate, ethyl-2-methyl propanoate, ethyl butanoate, and ethyl hexanoate dominate the odor, along with somewhat fermented ethanol and acetaldehyde. Ethanethiol and ethyl-2-methylbutanoate intensely elevated during late ripening, although D-limonene prevailed early. Short-chain fatty acid esters were performed early on, whereas branched-chain amino acid esters increased significantly in overripe fruit. Valine, leucine, isoleucine, and methionine increased 1.07–1.29-fold from unripe to overripe, while cysteine and glutamic acid decreased 1.11–1.25-fold. Propionic acid (C3) was found throughout, whereas acetic acid (C2) increased significantly 22-fold from ripe to overripe stages. The main free fatty acids throughout maturation were palmitic (C16:0) and Z-9-oleic (C18:1). Linoleic acid (C18:2) fell by 25% from unripe to ripe pulp, but linolenic acid (C18:3) increased 44%. Lipoxygenase activity increased throughout maturation, notably in overripe pulp, promoting fatty acid breakdown and volatile generation. From unripe to overripe, aldehyde dehydrogenase and alcohol acetyltransferase activity increased 1.6- and 1.8-fold, respectively. These findings demonstrate that the coordinated metabolism of fatty acids and amino acids, mediated by key enzymes, drives ester biosynthesis during durian fruit ripening.
Characterization of Banana Fiber-Reinforced Bioplastics for Environmentally Friendly Packaging Applications
This study explores the biocomposites composed of poly(butylene succinate) (PBS) reinforced with alkali-treated banana sheath and banana leaf fibers. The fibers were treated with 5% sodium hydroxide (NaOH) and incorporated into the PBS matrix at varying mesh sizes (40 and 60) and fiber contents (1, 2, and 5 parts per hundred resin (phr)). The composites were evaluated for melt flow rate (MFR), melt volume rate (MVR), tensile properties, impact strength, hardness, and microstructural characteristics using X-ray tomographic microscopy (XTM). The addition of both banana sheath and banana leaf fibers resulted in decreased MFR and MVR, while significantly improving the Young’s modulus, which reached up to 280 MPa in the composite containing 5 phr of fine banana leaf fibers. Impact strength was found to depend on both fiber size and loading, with the highest value of 10.8 kJ/m² observed in the composite reinforced with 2 phr of coarser banana sheath fibers. Microstructural analysis revealed that fiber dispersion, agglomeration, and void formation were key factors influencing mechanical performance. Furthermore, a prototype plant pot was successfully fabricated using the composite with the highest fine fiber and content, demonstrating the composite’s potential for sustainable product applications.
Advances in Leaf and Canopy Temperature Sensors for Precision Irrigation: A Review
Precision technologies are crucial for sustainable water management, as water scarcity and ineffective irrigation techniques continue to pose significant challenges in agriculture. One of the bases of plant-based irrigation scheduling is plant canopy temperature, which has become a reliable indicator of crop water status. The primary sensor technologies used to measure the temperature of leaves and canopies are discussed in this review, including integrated circuit sensors, thermistors, thermocouples, infrared thermometers, and infrared thermal imaging systems. Thermistors and thermocouples provide precise and affordable point-based measurements, but their scalability and installation are limited. For real-time canopy monitoring, infrared thermometers and thermal imaging provide non-contact options. Despite their higher price, thermal cameras enable the analysis of spatial variability. Low-cost irrigation system automation is made feasible by integrated circuit (IC) sensors, like the LM35, which combine accuracy and affordability. Research confirms that under deficit irrigation strategies, canopy temperature-based indices, notably the Crop Water Stress Index (CWSI), improve water use efficiency and enhance yield responses. However, sensor calibration, environmental variability, and the balance between accuracy and cost continue to be ongoing challenges.
Enhancement of Flexural Strength Capacity of RC-Beams using LC-GFRP Plates with Effective Debonding Techniques
Strengthening of reinforced concrete (RC) beams by externally bonded Carbon Fiber Reinforced Polymer (CFRP) is found to be a very effective method to increase their flexural strength capacity. However, the strengthening cost of the CFRP technique is very high and clients tend to avoid such expensive retrofitting methods. An alternative strengthening material, such as Glass Fiber Reinforced Polymer (GFRP), is a much less expensive material compared to CFRP. The GFRP strengthening method can achieve comparable strength gain and is an effective solution for strengthening RC beams. However, due to the lower strength and stiffness, a larger thickness of GFRP is required to obtain the target tensile strength. This increase in fiber thickness results in the commonly observed debonding failure of the GFRP-plated RC beams. Therefore, this study investigates the end anchoring technique by testing five beams under three-point bending. The first beam served as a controlled beam, while the second and the third beams were strengthened with one and three layers of GFRP to investigate the effect of the number of GFRP layers on debonding behavior. Anchored bolts were used to prevent debonding in the fourth specimen. The innovative W-shape inclined jacket technique was used for the last specimen. The test results revealed that the GFRP could effectively increase the beam's flexural strength. Nevertheless, when a larger number of GFRP layers was used, the debonding of GFRP occurred at an early loading stage. With the anchored bolted technique, the flexural strength of the RC beam was found to increase twice compared to the controlled specimen before failure due to the pulling off of the anchored bolts. Widespread shear cracks were observed near the failure stage. For the W-shape inclined jacket strengthening technique, the flexural strength was increased to a similar order as the anchored bolted technique, but the failure mode was due to slippage of the GFRP against the W-shape inclined jacket. Due to the use of a W-shape inclined jacket, the shear strength of the beam increased significantly. Therefore, the crack patterns near the final stage were controlled by flexure. The test results revealed that both techniques are effective methods to enhance the flexural strength of the GFRP-strengthened beam by achieving a similar magnitude of strength gain but failing in different failure mechanisms.
The Missing Link: Bridging Laboratory Biorefineries to Industrial Implementation
Utilization of Biomass Waste as Absorbents for Groundwater Purification
Calcium carbonate (CaCO₃) in groundwater is a major concern, as it can cause scaling in pipes and potentially pose health risks, particularly in rural areas. Developing innovative groundwater filtration systems capable of reducing CaCO₃ content is therefore essential for improving water quality. This study investigated the use of biomass waste from candlenut shells and corn cobs as sources of activated carbon adsorbents for portable groundwater filtration in the Sumbawa Region, Indonesia. A portable filter system was designed using varying amounts of adsorbent (150, 250, and 500 g), and its performance was evaluated based on several water quality parameters, including temperature, total dissolved solids (TDS), pH, taste, odor, turbidity, and CaCO₃ concentration. The results showed that the groundwater temperature remained stable (31–33 °C) with no significant changes observed. Both candlenut shell and corn cob adsorbents effectively reduced TDS, pH, taste, odor, turbidity, and CaCO₃ content. Corn cob adsorbents generally performed better, likely due to their more developed microporous structure, while candlenut shells reduced carbon release more slowly. Corn cob adsorbents achieved the highest reductions in TDS, CaCO₃, and pH, while candlenut shells showed better performance in sensory quality by reducing taste scores and odor intensity. Turbidity decreased by up to 91% using candlenut shells (to 0.24 NTU) and 90% using corn cobs (to 0.28 NTU). These findings highlight the potential of converting agricultural biomass waste into low-cost activated carbon absorbents for sustainable groundwater purification in rural communities.
Advances and Emerging Alternatives in Modified Cellulose Nanocrystals for Elastomer Reinforcement: A Review
Cellulose nanocrystals (CNCs) are increasingly recognised as sustainable nanofillers for elastomer composites due to their biodegradability and excellent mechanical properties. However, their inherent hydrophilicity limits compatibility with hydrophobic elastomer matrices, creating significant challenges for effective reinforcement. To overcome this, significant progress has been made through surface modification strategies. Physical approaches such as adsorption and plasma treatment improve compatibility via non-covalent interactions. While chemical routes including etherification/esterification, grafting, silylation, and nucleophilic modification introduce covalent bonds that adapt CNCs surface chemistry to polymer matrices. Such modifications have been shown to reliably improve dispersion, strengthen interfacial adhesion, and enhance both the thermal stability and mechanical performance of elastomer composites when compared with those reinforced by unmodified CNCs. Lignin-containing CNCs (LCNCs) offer distinct advantages by combining inherent hydrophobicity, thermal shielding, and simpler processing, making them a promising bio-based alternative to extensively modified CNCs (M-CNCs). Nonetheless, industrial implementation remains constrained by process complexity, high costs, and performance trade-offs at different filler loadings.
Bittern-Derived Mg/Al Layered Double Hydroxide Adsorbent for Potential Ciprofloxacin Removal in Water Treatment Application
The presence of ciprofloxacin (CIP), an antibiotic, in pharmaceutical wastewater has emerged as a significant environmental concern. This study presents the synthesis of magnesium/aluminum layered double hydroxide (MAL) through a co-precipitation method, utilizing seawater bittern as the magnesium source, with the objective of addressing CIP removal effectively. MAL was prepared at three different pH levels (5, 9, and 12), resulting in three distinct samples: MAL5, MAL9, and MAL12. Among these, MAL9 was identified as the most effective variant, exhibiting well-formed crystal structures alongside the highest adsorption capacity for CIP, achieving a removal rate of 63%. Moreover, we evaluated several factors that influence the adsorption process, including the dosage of the adsorbent, the solution’s pH, and the presence of co-ions. The findings indicated that optimal adsorption occurs at a concentration of 1 mg/mL within a pH range of 6 to 9, demonstrating significant resistance to both monovalent and divalent co-ions. The adsorption mechanism was further investigated through isothermal modeling (the Freundlich isothermal model), resulting in data that aligned with the Freundlich isothermal model, which indicated a maximum adsorption capacity of 95.15 mg/g at the concentration of CIP of 100 mg/L. Kinetic analysis showed that the sorption process follows a pseudo-second-order model, reaching equilibrium in about 100 minutes. The MAL demonstrated an impressive reusability, maintaining 90% to 50% performance over three adsorption-desorption cycles. Thus, bittern-derived MAL is an effective adsorbent for CIP removal and promotes the sustainable use of bittern waste as a magnesium precursor in functional nanomaterials synthesis.
Kinetic, Thermodynamic, Mass Transfer, and Determination of Controlling Steps in Pectin Extraction from Lemon Peel (Citrus limon L. Osbeck)
Lemon peel, a byproduct of citrus processing, contains high levels of pectin valued for its functional roles in food and pharmaceutical products. This study investigates pectin extraction using a mechanistic approach based on the Shrinking Core Model (SCM), which describes the progressive reaction of solid particles. The process follows first-order kinetics, with simultaneous extraction and degradation. Optimal conditions were 95 °C, pH 1.8, and 50 minutes, yielding 36% pectin. Key parameters included extraction rate constant k₁ = 0.0562 min⁻¹, degradation rate constant k₂ = 0.0039 min⁻¹, activation energies Eₐ₁ = 31.7 kJ mol⁻¹, Eₐ₂ = –22.9 kJ mol⁻¹, enthalpy change ΔH° = 76.05 kJ mol⁻¹, entropy change ΔS° = 0.23 J mol⁻¹ K⁻¹, and Gibbs free energy ΔG° < 0. The diffusion coefficient ranged from 0.055 to 0.06 × 10⁻¹⁰ m² s⁻¹ for 0.34 mm particles. The extraction process was controlled by both internal diffusion and chemical reactions. This study presents a novel integration of kinetic, mass transfer, and thermodynamic models, offering a predictive framework for optimizing sustainable and energy-efficient pectin production from lemon waste.
Exploring the Potential of Cationic Modified Microfibrillated/Nanocellulose as Slow/Controlled Release Fertilizers: A Review
Conventional controlled-release fertilizers often rely on synthetic polymer coatings that are costly, non-biodegradable, and environmentally harmful. Biodegradable alternatives such as microfibrillated cellulose and nanocellulose have attracted significant attention for use as sustainable fertilizer coatings. Their high surface area and mechanical strength enable improved nutrient retention, moisture resistance, and reduced leaching. Cationic modification further enhances coating adhesion and nutrient binding, offering superior control of nutrient release compared with unmodified cellulose. This review evaluates recent progress in the development of cationic cellulose-based coatings, including cost considerations, biodegradation behavior under soil conditions, physicochemical interactions that regulate nutrient release, and potential industrial applications. Challenges and future directions are also discussed, highlighting the role of cationic cellulose in advancing environmentally friendly fertilizer technologies.
Evaluating Urban Foliage for Bioindicator Potential through Pollution Tolerance Traits and Particulate Matter Accumulation
In this study, ten different plant leaves were collected from different urban microenvironments in the Hyderabad metropolitan area to assess their potential as bioindicators of air pollution. The collected leaf samples were analysed for surface PM accumulation, total chlorophyll concentration, carotenoid content, ascorbic acid, leaf extract pH, relative water content, and air pollution tolerance index (APTI). Out of ten plants, Ficus religiosa, which is located near the roadside, showed the highest PM accumulation with 54 µg/cm2. Tecoma stans showed the highest APTI value of 7.45 and ascorbic acid content of 10 mg/g, exhibiting greater tolerance to pollution, as well as potential for urban greening and air quality enhancement. Senegalia caesia with low APTI showed excellent carotenoid concentration of 19.42 mg/g, indicating that the plant is pollutant-sensitive, but activates antioxidant defence in response to oxidative stress. Hierarchical clustering analysis revealed a decent grouping of plant species based on biochemical profiles, validating stress tolerance patterns and PM deposition. The study highlights how pollutant deposition is linked to plant health and suggests that plants with adaptive leaf traits are more capable of tolerating polluted conditions. The findings of the study suggest that sensitive plants like Senegalia caesia, Lantana camara L., can serve as effective bioindicators and passive monitors of pollution levels and urban greening initiatives, and tolerant plants like Wodyetia bifurcata and Tecoma stans may contribute to a sustainable solution for mitigating urban air quality and supporting long-term environmental planning in polluted urban ecosystems.
Preharvest Shellac Fruit Coating at Mature Green Stage Delays Ripening Process and Alleviates Translucent Flesh Disorder of Harvested Mangosteen (Garcinia mangostana L.)
Translucent flesh disorder (TFD) is a major physiological problem in mangosteen fruit, often triggered by heavy rainfall during fruit maturation. This study demonstrated that preharvest applications of shellac coating effectively mitigated TFD. Mature–green fruits on the tree were coated with shellac (0, 5, and 10%) and exposed to simulated rainfall prior to harvest. Uncoated fruits subjected to water treatment exhibited a three–fold higher incidence of TFD upon ripening. In contrast, shellac–coated fruits, regardless of water treatment, showed a marked reduction in the disorder, with higher shellac concentrations offering greater protection. The shellac coating functioned as a physical barrier, preventing water infiltration and maintaining normal pericarp moisture at approximately 70%, whereas the pericarp of TFD–affected fruit reached 74%. Sequential pectin extraction from affected arils revealed elevated levels of Na₂CO₃–soluble pectin, suggesting that cell wall modifications contribute to increased aril firmness and the characteristic translucency of the tissue. In addition to preventing TFD, the shellac coating delayed ripening and extended postharvest shelf life by approximately one week. These results indicate that preharvest shellac coating during the rainy season is a promising strategy to reduce the incidence of TFD and extend the postharvest shelf life of mangosteen fruits.
Microbial Community Structure and Nitrogen in a Saline Filter Bioreactor Inoculated with Shrimp Pond Sludge
Understanding the composition of microbial communities is essential for optimizing anammox-based nitrogen removal in saline wastewater environments. This study examined the microbial diversity and ecological structure within a filter bioreactor inoculated with shrimp pond sludge and operated under saline conditions (30.1–33.0 ppt) and fed with synthetic seawater containing 70 mg-N/L of ammonium and nitrite with hydraulic retention time 24 h. Over 175 days of operation, the reactor maintained stable nitrogen removal, with peak ammonium conversion and nitrogen removal efficiencies of 46.25% and 44.33%, respectively. High-throughput 16S rRNA gene sequencing illuminated a diverse microbial community, dominated by Candidatus Brocadia (8.07%), alongside significant representations of Candidatus Jettenia (0.88%). The microbial consortium also included key nitrifying bacteria such as Nitrosomonas and Nitrospira, indicating synergistic interactions in nitrogen transformation. These taxa play key functional roles in nitrogen transformation, biofilm stability, and adaptation to saline, anoxic environments. Phylogenetic analysis showed close affiliations between amplicon sequence variants and recognized anammox species, such as Candidatus Brocadia sinica and Candidatus Jettenia asiatica. The detection of freshwater-associated anammox genera in a saline system highlights their ecological adaptability and potential application in saline wastewater treatment. Overall, this study provides insights into microbial consortia that drive anammox processes in engineered saline environments and supports the development of biological nitrogen removal strategies for marine and coastal applications.
Retraction notice to "Optimization of CO₂ Gas Flow Rate and Distributor Holes Number for CO₂ Capture" [Applied Science and Engineering Progress (2026) .05.001]
Cover Vol. 19, No. 3, July–September 2026
Cover Vol. 19, No. 3 July–September 2026
Process Modelling and Optimization of Palm Oil Biodiesel Production Using Aspen Plus and Response Surface Methodology
The Effect of CaCl2 Cross-Binding Agent Concentration on Alginate-Carboxymethyl Cellulose-Oil Palm Empty Fruit Bunches Gel Granules as a Methylene Blue Adsorbent
Water pollution caused by synthetic dye waste, such as methylene blue, poses a serious environmental problem due to its resistance to natural degradation. This issue can be addressed by utilizing carboxymethyl cellulose (CMC) derived from oil palm empty fruit bunches (OPEFB), which not only helps reduce palm oil industry waste but also produces value-added materials for environmental applications. This study aimed to investigate the effect of varying concentrations of calcium chloride (CaCl₂) as a crosslinking agent on the synthesis of alginate–CMC gel beads derived from OPEFB, used as adsorbents for methylene blue wastewater. The study was conducted in three stages: synthesis, characterization, and application, using CaCl₂ concentrations of 3%, 4%, 5%, 6%, and 7%. The observed parameters included swelling ratio, functional group interactions (FTIR), surface morphology (SEM), and adsorption capacity for methylene blue. The results indicated that the optimal CaCl₂ concentration was 3%, achieving the highest swelling ratio of 65.35% and a maximum adsorption capacity of 3.59 mg/g. Characterization results showed that increasing the CaCl₂ concentration led to the formation of a denser gel structure with lower swelling capacity, as supported by SEM images, which revealed more compact surfaces at a 7% concentration. FTIR spectra confirmed the formation of ionic crosslinking between the polymer carboxylate groups and Ca²⁺ ions, as indicated by characteristic band shifts at 1614 cm⁻¹. The findings emphasize that controlling the CaCl₂ concentration is crucial for producing gel beads with optimal physical properties and enhanced adsorption performance.
DES Molar Ratio and Time-Driven Delignification of Pineapple Peel: Achieving Exceptional Lignin Removal and Cellulose Enrichment
This study examined the influence of Deep Eutectic Solvent (DESs) molar ratio and reaction time on the delignification of pineapple peel as a lignocellulosic biomass. Lactic acid was employed as the hydrogen bond donor (HBD), while choline chloride, betaine hydrochloride, and glycine were used as hydrogen bond acceptors (HBAs). The DESs molar ratios investigated were 1:4, 1:6, 1:8, and 1:10. Delignification was conducted at 121°C for 1, 2, and 3 h. The lignin, hemicellulose, and cellulose contents before and after delignification were determined using the Chesson–Datta method. Structural and morphological modifications of the biomass were evaluated by FTIR, SEM, and XRD analyses. The highest lignin removal was achieved using betaine:lactic acid DES with a molar ratio of 1:6 for 1 h. Under this condition, lignin removal reached 96.87%, with hemicellulose and cellulose contents of 7% and 79%, respectively. These results indicated that betaine:lactic acid DES effectively disrupts lignin bonds in pineapple peel compared to other DESs without damaging cellulose.
Influence of Novel Hydrofluoric Acid and Nitric Acid Etchants on Performance of Photochemical Machining of Ti-6Al-4V alloy for Biomedical Applications
Photochemical machining (PCM) process is widely recognized for fabrication of precision engineering parts and components. This study examines the impact of novel hybrid Hydrofluoric Acid (HF) and Nitric Acid (HNO₃) etchant compositions on the PCM performance for cutting square-shaped (5 mm × 5 mm) cavities in Ti-6Al-4V alloy for biomedical component manufacturing. A total of 25 experiments were performed to determine the effects of etching composition and time on edge deviation (ED), material removal rate (MRR), and mean roughness depth (Rz). The novel HF-HNO₃ etchant enables precise PCM machining of Ti-6Al-4V, achieving minimum ED (29 µm) and Rz (1.82 µm) and maximum MRR (0.967 mg/min). The HF-HNO₃ composition was found to significantly affect etching kinetics, thereby affecting process productivity and the integrity of the machined surface. The findings provide deep insight into the etching behaviour of Ti-6Al-4V and establish process directions for applying PCM in the manufacturing of biomedical components.
Improvement of Sheet Metal Properties by Inducing Residual Stresses into Sheet Metal Components by Embossing and Reforming
In sheet metal forming, combination of embossing and reforming allows the mechanical properties of sheet metal materials to be specifically improved. Here, local property modification is achieved by the residual stresses induced as a result of the one-sided embossing process followed by a reforming step. The residual stresses induced in this specific way can lead to a significantly increase in the fatigue strength of processed sheet metal components. However, in order to ensure this kind of component optimization in continuous operation, the induced stresses have to be homogeneous. In this respect, the main objective of the study reported about in this paper was to identify a forming strategy, consisting of the process steps embossing and reforming, that generates preferably homogeneous residual stress distributions into sheet metal blanks. For this, numerical and experimental investigations were carried out with samples of the stainless steel (X6Cr17) having a thickness of 1.5 mm. It was found that embossing and reforming, integrated into a conventional forming process, is a novel approach to specifically induce very localized homogeneous compressive residual stresses in sheet metal materials. This eliminates the need for costly post-processing by means of surface treatment.
Natural Fiber-based Green Composites: Processing, Properties and Biomedical Applications
Since the advent of modern technological civilization, tremendous pollution has been emerged in our environment by disposing of waste material in the environment unconsciously. Some waste materials are biodegradable and some of them are non-biodegradable. Biodegradable waste, originated from plants or animals, can be decomposed by the natural organism (bacteria, fungi, etc.) and can be excluded from pollution. This degradation process may be rapid or slow but the environmental risks are low. On the other hand, non-biodegradable waste, obtained from inorganic components cannot be decomposed by the natural organism and act as a source of pollution. These wastes are being generated by humans, and every year billions tons of wastes are being dumped into the environment which puts our environment in danger. As a result, environmental consciousness has increased worldwide. This growing ecological and environmental awareness leads the world to develop eco-friendly materials. As the population grows day by day, it is not possible to reduce waste. So, it is wise to focus on developing new materials that would produce biodegradable waste. Recently, the attraction on the biocomposite (known as green composites) materials has significantly increased because it is generated from natural fiber which is biodegradable and it has the potential of being a substitute for conventional non-biodegradable products. Biocomposites are used in various industrial sectors, including the bio-medical industry. In this paper, the overall idea of natural fibers, extraction and surface modification methods of natural fiber, natural fiber-based biocomposites, fabrication and properties analysis of biocomposite, and recent applications of biocomposites in the medical sector have been reviewed. The primary incentive for developing and using biocomposite is to build a new generation of eco-friendly materials by replacing synthetic ones.
A Decision Support System for Consumer Behavior of Chinese In-bound Tourists on Functional Beverage: An Empirical Study during COVID-19 with Thailand Sandbox
The COVID-19 pandemic has challenged all business owners to maintain their businesses and find ways to cope with the uncertainty. The functional beverage market has shifted its focus to consumers’ health value and wellness while its operators still lack knowledge to develop their products to serve customer needs, particularly to penetrate new customer groups, which are tourists. Therefore, the objective of this research is to investigate major influential factors of consumer behavior and create a decision support system (DSS) of consumer behavior (CB) on functional beverage. Samples are 378 Chinese tourists who visited Thailand in 2019 before the COVID-19 outbreak. The structural equation modeling (SEM) was employed to analyze the data while the sensitivity analysis was to test model robustness. The results showed that motivation, reference group, and knowledge have indirectly influenced CB (buying behavior, brand consciousness, health consciousness, and quality consciousness) through Marketing Mix (MM) while MM has a direct influence on CB. Moreover, sensitivity analysis expressed that either increasing or decreasing place and decreasing knowledge can influence CB factors. These results confirmed that consumers in the new normal market were interested in brands, quality, and health; therefore, brand consciousness/brand creation was a crucial challenge for small and medium-sized enterprises (SMEs) in the industry as they needed to improve product quality and be informative in terms of products’ health benefits. Hence, SMEs had to develop the product serving customer needs, gaining competitive advantages, and boosting up the economic cycle of the whole tourism supply chain from Thailand’s sandbox project. The value of DSS can help entrepreneurs decide to produce beverage to meet Chinese tourists’ satisfaction and to save cost for product development. It is an applicable tool for entrepreneurs, chiefly SMEs, to penetrate a new tourism market and choose a new suitable product that serves consumer needs in terms of tastes, brand awareness, and health benefits in the post-pandemic era.
Effect of Tool Rotational Speed and Traverse Speed on Friction Stir Welding of 3D-Printed Polylactic Acid Material
Joining of polymers are usually carried out using adhesives that has a deteriorating quality at elevated working conditions thus limiting its application areas. Friction stir welding (FSW) is a growing solid-state welding technology, with applications including the welding of lightweight materials. FSW was recently introduced for joining thermoplastics materials and found successful. This study attempts in employing FSW to join polylactic acid (PLA)-based 3D printed engineering components and assess the effect of FSW process parameters (tool rotational speed and traverse speed) on the weld property. The present work uses the FSW process to butt weld 5 mm thick 3D printed PLA sheets with taper cylindrical profiled tool. For the experimentation, three different combinations of feed rates and pin rotational speeds are considered. Based on joint efficiency evaluation, it is found that tool rotational speed of 1400 rpm combined with 10 mm/min transverse speed produces the weld with high joint efficiency of 40%.
Utilization of Supercritical Carbon Dioxide and Co-solvent n-hexane to Optimize Oil Extraction from Gliricidia sepium Seeds for Biodiesel Production
This study was conducted to optimize the supercritical carbon dioxide (scCO2) extraction of oil from Gliricidia sepium seeds using response surface methodology. Initial experiments were carried out using scCO2 and scCO2 with co-solvent n-hexane to determine the effect of co-solvent addition in oil yield. In order to obtain the maximum yield, experiments were conducted using Response Surface Methodology - Face Centered Central Composite Design (RSM – FCCD) under the following conditions: pressure of 20, 30, and 40 MPa, temperature of 50, 60, and 70°C, and CO2 flow rate of 2, 2.5, and 3 mL/min. A second-order polynomial with extended cubic interaction model was significantly fitted (p < 0.05), and a high coefficient determination value (R2 = 0.98) was recorded. At a constant extraction time of 60 minutes, the best extraction yield (12.12%) was obtained at 60°C, 40 MPa, and 2.5 mL/min. The pressure, temperature, and CO2 flow rate were all found to have a significant effect on the oil yield. The oil was used in biodiesel production and its methyl ester composition was analyzed using Gas Chromatography-Flame Ionization Detector (GC-FID).
Properties of Mortars Mixed with Polystyrene and Hemp Fiber Wastes
When polystyrene (PS) and hemp fiber waste were mixed into the sand aggregate, some physical-mechanical properties of mortar changed. The PS and hemp fiber were tested as partial replacements for sand in mortar with three designated percentages of 2.5, 5.0 and 10.0% by mass. The properties of mortar with PS were found to be better than that of the mortar with hemp fiber. The water absorption of mortar with PS was comparable with the reference mortar but lower than that of mortar with hemp fiber. The compressive strength of the mortar with PS was higher than that with hemp fiber whereas the tensile strength of the mortar with 2.5% PS and hemp fiber was comparable and was higher than that of the reference mortar. The thermal conductivity of a wall plastered by mortar containing PS decreased as the PS content was increased, whereas the thermal conductivity of a wall plastered by mortar containing hemp fiber increased as the hemp fiber content was increased. Thick crack was detected in the reference wall while hair line crack occurred from the wall plastered with PS and hemp fiber mortars. The results indicated that 10.0% PS could be used as a partial replacement for sand in mortar with an improvement in some of the properties of the mortar.
Effects of Aging and Infill Pattern on Mechanical Properties of Hemp Reinforced PLA Composite Produced by Fused Filament Fabrication (FFF)
Additions of reinforcing natural fibers to polymer matrices provides an increase in mechanical properties. In addition, bio composite materials contribute to the sustainable ecosystem with their ease of recyclability. The effect of accelerated aging on the mechanical properties of PLA matrix biocomposite specimens has been observed in previous research. However, the effect of accelerated aging on the mechanical properties and the resulting mass loss of the material produced with fused filament fabrication (FFF) has been discussed for the first time in this study. Aging was applied to the biocomposite consisted of 10% hemp and PLA matrix produced at a constant rate, parallel to the tensile direction and cross (+/– 45°) angle, and the tensile stress and mass loss were examined. The aging effect has been observed even from the first week. Specimens with parallel printing to tensile direction showed a lower tensile performance than cross printing one. Since the structure in the laminates is quite durable, the adhesion performance in the laminate or through thickness direction has been low. Natural fibers are found so highly hygroscopic that chemical treatments will improve the interface and improve the mechanical properties.
The Influence of Fiber Processing and Alkaline Treatment on the Properties of Natural Fiber-reinforced Composites: A Review
Throughout generations, research on natural fiber-reinforced composites (NFRCs) has been growing and yielding promising results. The notion of blending natural fibers with polymers comes from the composite’s suitable properties, not limited to low density, availability at a low price, biodegradability, and environmental friendliness. The quest for high-performing and marketable NFRCs is driving innovation in the synthesis of such materials. A suitable combination of parameters that optimizes the mechanical and functional properties of the composites without increasing the cost of production is desired. The main objective of this review is to evaluate some of the parameters that influence the behavior and properties of NFRCs. The influence of alkaline modification and natural fiber processing parameters, such as particle size, modification concentration, soaking duration, processing temperature, fiber-to-polymer ratio, and adoption of additives, on composites are discussed. This review summarizes some of the work and provides some directions in the search of an all-around performing economic NFRC.
Mechanical, Absorption and Swelling Properties of Vinyl Ester Based Natural Fibre Hybrid Composites
Natural fibres such as Banana (B), Jute (J) and Kenaf (K) were hybridized in different stacking sequences in vinyl ester. The composites with hybridized fibres were tested to evaluate their tensile, flexural and impact properties. Further, they were also tested for their water absorption and thickness swelling behavior. The hybridization of the fibre mats had an encouraging outcome on the mechanical behavior. The JKBKBJ hybrid composite possessed the maximum tensile strength (34.12 MPa) while maximum stiffness of 1.667 GPa was observed for the KBJJBK hybrid composites. The observations from the flexural testing indicated that the hybrid composites resisted the flexural load for higher displacement. All the hybrid configurations presented better impact strength over the composites reinforced with kenaf and jute fibres. Among the hybrid composites investigated, the KJBBJK hybrid composite displayed highest impact strength (12.32 kJ/m2). The improved strength, stiffness and lower moisture absorption properties make the composites with hybridized fibres a potential candidate for the light weight structural applications.
Cationic Nanocellulose as Promising Candidate for Filtration Material of COVID-19: A Perspective
The threat of the novel coronavirus (COVID-19) pandemic is worrying as millions of people suffered from this outbreak. The COVID-19 can be airborne spreaded by attaching to human nasal or saliva secretion of an infected person or suspended fine particulates in the air. Therefore, in order to minimize the risks associated with this pandemic, an efficient, robust and affordable air‐borne virus removal filters are highly demanded for prevention of spreading viruses in hospitals, transportation hubs, schools, and/or other venues with high human turn‐over. Respirators such as N95, N99 and N100 as well as surgical masks have been widely used. To date, there is no filter standards or special filter technologies tailored for effectively adsorbing the airborne viruses. Studies had shown the electrostatic fibers were capable to entrap the negatively charged viruses including COVID-19. Researchers believed that the positive surface charge of filtration material is an important key to efficiently adsorb the negatively charged viruses. Nanocellulose has emerged as a new class of biobased material with promising potential application in the filtration of viruses. Nanocellulose is uniform in diameter and has excellent nanofibrillar morphology. To the best of our knowledge, further studies are necessary to determine the efficiency of cationic nanocellulose as filtration material of COVID-19.
A Review on the Philosophies for the Advancement of Polymer-based Composites: Past, Present and Future Perspective
Research has been consider as a tool for recycling existing scientific ideas to promote improved concepts for the development of new materials. All technological innovations have links with the ancient philosophies that are being adapted progressively. Given this, composite material development remains one of the most excellent methods to influence the environment to meet human needs. Various studies have shown that polymer-based composites have emerged as the leading group of composites that are fast displacing all other materials in several applications due to their inherent properties. Polymer-based composites can be entirely synthetic, completely natural, or a mixture of synthetic and natural-based. However, a recent desire for eco-friendly materials has shifted attention from complete synthetic-based materials to natural fibers, whether in a partial or a total replacement. Thus, this review provides an overview of research trends from synthetic to natural based polymer composites. The article also highlights the different intrinsic classifications of composites, their developments, areas of applications, and their projections into the future in line with considerations for environment and applications.
Thermal Stability and Tribological Behaviors of Tri-fillers Reinforced Epoxy Hybrid Composites
The present works investigates the thermal stability and wear behaviour of tri-fillers reinforced hybrid composites. The Silica (S), Coconut shell (C) and Graphite (G) fillers reinforced homogeneous and functional graded epoxy composites are prepared by vertical injection molding techniques. The effect of filler contents, design parameters and its interaction on wear and friction behavior of SCG composites has been investigated. With help of Taguchi’s techniques, L27 orthogonal array, a series of experiments are planned and conducted on pin-on-disc tribo machine with three different loading of 10, 20 and 30 N, three sliding velocities of 1, 1.5 and 2 m/s by varying the G filler content of 10, 20 and 30 wt% with constant weight fraction of S and C fillers of 10 wt%. The results shows that the increasing the Gr content was increased the wear resistance and rate. The optimization techniques used to determine the composites parameters.
Plant-Microbe Interactions - Insights and Views for Applications in Sustainable Agriculture
The term “microbiome” refers to the association of plants with various microorganisms which play an important role in the niches they occupy. These microorganisms are found in the endosphere, phyllosphere, and rhizosphere, of host plants which are involved in plant ecology and physiology. The structure and dynamics of the plant microbiome have been significant seen in the last few years. In addition, the plant microbiome enhances the host plant with gene pools, which is referred to as the second plant genome or extended genome. Interestingly, the microbiome associated with plant roots has received unique attention in recent years due to its important role in host nutrition, immunity, and development. Prospective studies of the microbiome have been coupled with the need for more sustainable production for agriculture. On the other hand, various environmental factors are associated with plant-microbiome interactions that can affect composition and diversity. This review provides insights and views of plant microbiome for sustainable agriculture. Host factors that influence the microbial community, root-associated microbial consortium, commercial application, and limitation of plant microbiome were discussed. Also, this review provides current knowledge of the plant microbiome into potential biotechnology products that can be used in agricultural systems. Regardless, microbiome innovation represents the future of sustainable agriculture.
Antifungal Activity of Silver Nanoparticles with the Potential to Control Fungal Contamination in the Male Inflorescences of Palmyra Palm
Fungal contamination of the male inflorescences of palmyra palm (Borassus flabellifer Linn.) is a serious problem during their storage prior being used as the raw material for making the local One-Tambon-One-Product, a cloth holder known as “Nguang Taan Hom” made by the Phutaan Entrepreneurship, Takua Thung District PhangNga Province, Thailand. Morphological and molecular techniques were used to identify the isolated fungi from male palmyra palm inflorescences. Three major strains: Aspergillus niger, Aspergillus fumigatus and Aspergillus sclerotiorum were studied for antifungal activities and the minimum inhibitory concentration (MIC) of silver nanoparticles (AgNPs) was found to range from 13.5–27 mg mL–1. Then, the efficiency of the AgNPs and silver nanoparticles stabilizing by Polyvinylpyrrolidone (AgNPs-PVP) on the male palmyra palm inflorescences was studied by constructing a chamber model over a period for 9 weeks. The results showed that the group inoculated with Aspergillus niger, Aspergillus fumigatus and Aspergillus sclerotiorum spores developed fungal growth after 4 weeks whereas no fungal growth was observed in the group treated with AgNPs and AgNPs-PVP at 27 μg/ mL until week 7, indicating that dipping with either AgNPs or AgNPs-PVP is able to inhibit the growth of the fungi which cause damage to raw materials and also threaten human health. Therefore, it can effectively extend the storage time of male palmyra inflorescences.
Influence of Sulfuric Acid Pretreatment and Inhibitor of Sugarcane Bagasse on the Production of Fermentable Sugar and Ethanol
Improper disposal of agricultural waste after harvesting season has posed serious health and environmental issues. Alternative methods to utilize agricultural waste to produce a value-added product, especially biofuel, have become the focus of research and industrial stakeholders. To make the process feasible, the maximum conversion should be achieved with the optimum operational condition. This research applied Response Surface Methodology (RSM) with the Box-Behnken design (BBD) to optimize sulfuric acid pretreatment of sugarcane bagasse by varying three pretreatment factors namely, acid concentration (0.5–3.5%), temperature (60–140℃), and time (20–100 min). Pretreated biomass was enzymatically hydrolyzed, and the effectiveness of pretreatment was examined according to the reducing sugar concentration. However, inhibitors namely, acetic acid, 5-hydroxymethylfurfural (5-HMF), and furfural were produced during pretreatment, which was analyzed through GC-MS analysis. The Box-Behnken design could optimize and correlate the effect of pretreatment parameters on the hydrolysis of sugarcane bagasse. The optimum pretreatment condition was predicted at an acid concentration of 3.50%, the temperature of 136.08℃, and the time of 75.36 min to obtain the maximum sugar production. Sugarcane bagasse pretreatment at optimum condition could produce a reducing sugar of 180.15 mg/g-sugarcane bagasse, which is 3.06 folds higher than untreated sugarcane bagasse. However, ethanol yield from pretreated biomass was less than unpretreated biomass because of the inhibitor formation. This study provides a new insight into utilizing agricultural waste in a more efficient and eco-friendly manner.
Influence of Incident Energy on Sisal/Epoxy Composite Subjected to Low Velocity Impact and Damage Characterization Using Ultrasonic C-Scan
Impact resistance is an inevitable characteristic of the composites employed in the high performance structural applications. Due to the growing interest in the use of sisal fibre as reinforcement in the polymer composites, it is required to determine the response of sisal/epoxy composites to low velocity impact at high incident energies where perforation can occur and assess the damage characteristics using a non-destructive technique. In this work, sisal/epoxy composites were subjected to drop weight impact in the velocity range of 3 m/s to 5 m/s at different energy levels between 20 J to 50 J according to the ASTM D7136. Based on the results observed, it is concluded that both the peak load and absorbed energy increased with the increasing incident energy level up to 40 J. At 50 J, perforation occurred and the maximum deformation was approximately 22 mm for the sisal/ epoxy composite. Damage characteristics and failure behaviour of the composite at different incident energies was examined from the visual images of the front and back face of the composite. The quantitative assessment of crack propagation in the sisal/epoxy composite and the damage area were determined from the ultrasonic C-scan images of the sample post impact at various energy levels.
Chemical Pretreatment of Lignocellulosic Biomass for the Production of Bioproducts: An Overview
Lignocellulosic biomass has attracted great interest from researchers. It was due to the abundance of this valuable material which can be converted into value-added materials such as nanocellulose, biocomposites, bioelectricity, biohydrogen and biosugars. Lignocellulosic biomass is consisting of the three major components which are cellulose, hemicellulose and lignin. In order to utilize lignocellulosic biomass for bioproducts manufacturing, they need to be pretreated prior to further processing. Pretreatment can be carried out either by mechanical, chemical, biological or combination of all these methods. Chemical pretreatment is the common method used to pretreat the lignocellulosic biomass in order to completely or partially remove the components. During the past few years, a large number of chemical pretreatment including lime, acid, steam explosion, sulfur dioxide explosion, ammonia fiber explosion, ionic liquid and others have been discovered to be efficient pretreatment of biomass. Several types of chemical pretreatment of fibers and their future direction and also challenges were tackled in this review. This review could be beneficial for future directions in the pretreatment of fiber for the development of several products.
Statistical Study of the Influence of Fiber Content, Fiber Length and Critical Length in the Mechanical Behavior of Polymeric Composites Reinforced with Carica Papaya Fibers (CPFs)
Vegetable fibers are excellent substitutes for manmade fibers because they are resistant and sustentables. This article studied the potencial application of Carica Papaya Fibers (CPF) in polymerics composites of natural resin. A simple model of micromechanical analysis was used for prediction of breaking stress, strain and Young’s modulus in composites with short fibers of Carica Papaya and matrix of polyurethane resin obtained from Ricinus Communis vegetable. The fiber contents were varied between 10–35% and fiber lengths were varied between 3–6%. The result analysis was performed using analysis of variance (ANOVA) to assess the influence of variables on the mechanical properties of each composite produced. The results showed that that increased in fiber length promoted increase in stress values, while the increase in fiber content favored the increased in the stiffness of the composite.
Performance Enhancement of Recycled Aggregate Concrete – An Experimental Study
Extensive studies have been performed on the mechanical and durability properties of the concrete prepared with recycled coarse aggregates (RCA), however, only modest consideration has been given to the studies on the behaviour of RAC prepared by alternative mixing approach techniques. This study presents the mechanical properties of the recycled aggregate concrete (RAC) with different percentages of RCA prepared by normal mixing approach (NMA), two-stage mixing approach (TSMA) and sand enveloped mixing approach (SEMA) techniques. The manufactured concrete mixtures were tested for compression, tension, flexure and elastic modulus at 7, 28 and 90 days. The results indicate that the mechanical properties of the RAC (with 100% of RCA) prepared through TSMA and SEMA were improved by 9.36 and 12.14% at 28 days. Perhaps, prolonged curing to TSMA and SEMA mixtures improved the mechanical properties of the RAC that is nearly equal to normal aggregate concrete (NAC) prepared by NMA.
Desirability of Tribo-Performance of Natural Based Thermoset and Thermoplastic Composites: A Concise Review
Tribology, which may be defined as an interdisciplinary subject, deals with relative motion between two or more bodies, i.e., surfaces that are interacting relatively. Thus, tribology is a science covering three vital classes, namely, wear, friction and lubrication. The focus of this article is to bring out the elements that are influencing the wear-resisting behavior of thermosetting and thermoplastic composites with natural-based constituents. Based on the literature resources, the treatments on the natural fibers acting as reinforcement, and the addition of fillers in resin acting as matrix could improve the wear-resisting behavior of the composites. Additionally, other conditions such as sliding speed, sliding velocity, sliding distance and operating temperature could also influence the friction coefficient and specific wear rate of the natural-based composites.
Design and Application of a Modified EWMA Control Chart for Monitoring Process Mean
The modified exponentially weighted moving average (modified EWMA) control chart is an improvement on the performance of the standard EWMA control chart for detecting small and abrupt shifts in the process mean. In this study, the effect of varying the constant and exponential smoothing parameters for detecting shifts in the mean of an autoregressive process with exogenous variables (ARX(p,r)) with a trend and exponentially distributed white noise on the standard and modified EWMA control chart was investigated. The performances of the two control charts were compared via their average run lengths (ARLs) computed by using explicit formulas and the numerical integrated equation (NIE) technique. A comparative study of the two ARL methods on the modified and traditional EWMA control charts shows that the modified schemes had better detection ability at all levels of shift size. Finally, two examples using real datasets on gold and silver prices are given to illustrate the applicability of the proposed procedure. Our findings advocate that the modified EWMA chart is excellent for monitoring ARX(p,r) processes with exponentially distributed white noise
Trends and Developments in Natural Fiber Composites
Cleaner Environment Approach by the Utilization of Low Calcium Wood Ash in Geopolymer Concrete
The waste disposal issues were the most severe problems that could cause global warming, which depletes the environment. The research hypothesis was to find the suitability and sustainability of utilizing the waste by-products in the invention of green geopolymer concrete to eliminate the tremendous effects caused by the wastes. Due to the increased demand for fly ash in recent years, the requirement of high alkaline activators, and elevated temperature for curing, there was a research gap to find an alternative binder. The novelty of this research was to utilize the waste wood ash, which is available plenty in nearby hotels and has an inbuilt composition of high potassium that can act as a self alkaline activator. Waste wood ash procured from the local hotels was replaced with fly ash by 0 to 100% at 10% intervals. The setting and mechanical characteristics were found on the prolonged ages to understand the influence of waste wood ash. Microstructural characterization was found using Scanning Electron Microscope and X-Ray Diffraction Analysis to define the impact of waste wood ash in the microstructure. The research findings showed that replacing 30% waste wood ash with fly ash attained better performance in setting properties and all mechanical parameters. The obtained optimum mix could provide the best alternative for fly ash in geopolymer to eliminate the economic thrust by the requirement of alkaline activators and deploy the environmental impact caused by the waste wood ash.
Understanding and Efficiently Manipulating Environmental Stress Caused by Metal Ions to Improve Ethanol Fermentation
The inconsistent quality of molasses directly influences ethanol production, particularly due to contamination by metal ions that causes severe problems and reduces production efficiency. This research focused on calcium (Ca2+), potassium (K+), and magnesium (Mg2+) ions that are common in molasses. The key objective was to understand clearly the effect of ions on ethanol fermentation and Saccharomyces cerevisiae performance. Individual ions and ion mixtures were studied in sucrose solution and in molasses. The results showed that severe stress could be ordered as Ca2+>K+>Mg2+ and the adverse effect was greater when the ion concentration increased. Ca2+ was a strong inhibitor while trace amounts of Mg2+ produced a positive effect. To achieve the greatest efficiency in ethanol production using molasses in the substrate preparation, Ca2+ should not exceed 0.18% (w/w) prior to fermentation and the final sugar concentration should be 20–25% (w/v), as adjusting the addition of sucrose will result in a suitable yeast medium. Pretreatment and dilution were the best practices for ion removal, with Ca2+ being clearly decreased. Furthermore, determination of the composition and ion concentration in molasses are essential initial steps that must be routinely applied to ensure that the knowledge gained and the efficient techniques investigated can both be used to improve ethanol production.
Dynamic Mechanical Performance of Natural Fiber Reinforced Composites: A Brief Review
Natural fiber reinforced polymer composite is a much focused area of study owing to its environmentally friendly nature and good mechanical properties. These composites offer comparable mechanical properties to that of steel and other composite materials. Dynamic mechanical analysis is a widely used technique to investigate the mechanical performance of fiber reinforced composites at a wide range of temperatures. Using this technique, the thermal transitions and damping properties of fiber reinforced composites can be studied. These natural fiber composites are widely employed in structural applications in many industries. Here, in this short review we have presented the recent works on the dynamic properties of natural fiber reinforced composite materials with an essence of the influencing factors
High Priority Arbitration for Less Burst Data Transactions for Improved Average Waiting Time of Multi-Processor Cores
The multi-processor cores in SoC which have high burst data transactions can play a critical role while accessing the shared resources such as the off-chip memory. These processor cores can starve other processor cores that have less burst data transactions while accessing the same shared resources. The starving issue of other processor cores leads to degrade the entire system performance of the SoC. However, the arbiter architecture in the SoC design plays the best solution to manage different processor core requests and granting one of them to access the shared resources according to different scheduling algorithms. In this paper, we have designed AXI interconnect, which includes arbiter architecture to connect four processor cores represented by the AXI masters and the off-chip memory represented by the salve. Each processor core (AXI Master) uses the AXI4 interface protocol to improve the system performance and the arbiter based on the static fixed-priority algorithm to improve the average waiting time for all the processor cores. The SoC design architecture is modeled in System Verilog HDL; simulation and synthesis are done by using the Vivado tool and FPGA ZYNQ-7 ZC702 Evaluation Board (xc7z020clg484-1).
Fabrication and Experimental Testing of Hybrid Composite Material Having Biodegradable Bagasse Fiber in a Modified Epoxy Resin: Evaluation of Mechanical and Morphological Behavior
Natural fibers such as bagasse, jute, sisal and coir are biodegradable as well as non-toxic in nature, so the use of natural fiber is safe. Bagasse contains about 50% cellulose, 25% hemicellulose, and 25% lignin. The present work has been undertaken to develop a composite using bagasse fiber as reinforcement and to study its mechanical properties, morphology, water absorption capacity and performance. The composites were prepared with different weight percentage of bagasse fiber by hand lay-up method. In the present research work, it can be concluded that with increase in wt% of bagasse fiber in matrix material the rate of water absorption increases. Ultimate tensile strength, ultimate compressive and flexural strength of the composite are less than the pure epoxy while Young’s modulus is higher for composite. Ultimate tensile, ultimate compressive strength and flexural strength of composite is decreasing at all cross head speed with increase in wt% of bagasse fiber while flexural strain is increasing. Scanning Electron Microscopy (SEM) showed that for 5 wt% of bagasse fiber the binding between epoxy and bagasse fiber is better than the 10 and 15 wt% of bagasse fiber configuration. This was because of the increase in wt% of bagasse fiber, which results in cavities and improper binding in the composite domain. Thus, as we increase the wt% of bagasse fiber, it causes the decrease in mechanical properties of composite.
Spanish Broom Fibres Properties and Extraction for Application in Composites: A Review
The development of a number of natural fibre products for textiles was attempted during the period of Italian autarchy (1935–1943) under the direct support of the Fascist regime. Among these fibre products, Spanish broom fibre is derived from the stem of Spartium junceum, a spontaneous plant in large parts of Italy, especially in the Southern region of Calabria. The extraction of the fibre proved cumbersome though, especially for the hardness of the stem. Therefore, different retting processes were developed, mechanical, chemical and also bacterial and, in the latter case through the use of Clostridium felsineum, it was proved to be effective to a point allowing the production of textiles. The historical events linked to the fall of the dictatorship led to some oblivion and also to the possible loss of archive materials. The objective of this review is to elicit ideas and developments concerning an effective extraction and degumming of Spanish broom fibres and evaluate the more recent applications to the field of biocomposites.
Effects of Enzyme Types and Extraction Conditions on Protein Recovery and Antioxidant Properties of Hydrolysed Proteins Derived from Defatted Lemna minor
Lemna minor (L. minor), the common duckweed, contains a high protein substance and is considered as a good source of potential bioactive peptides. The objective of this study is to investigate the effect of enzymatic hydrolysis times (60–180 min) and enzyme concentrations (0.5–3.5%v/w) with Alcalase and Flavourzyme on the recovery, hydrolysis degree (DH), and antioxidant properties of peptides derived from defatted L. minor. The protein recovery, hydrolysis degree (DH), and antioxidant activities obtained by enzymatic were compared with the alkaline treatment method. The results showed that the protein recovery, DH values, and antioxidant activities were enhanced by increasing the enzyme concentration and hydrolysis time. Specifically, the recovery of protein and DH values reached the highest level after the enzymatic hydrolysis by Flavourzyme or Alcalase at 1.5 v/w enzyme for 120 min. At the same enzymatic hydrolysis condition, the samples hydrolyzed by Flavourzyme had a higher inhibitory effect on the ABTS•+ and DPPH•+ radical scavenging than those hydrolyzed by Alcalase and the alkaline treatment. Further study also showed that the DH values, amino acid contents, and antioxidant activities of the protein extracts were positively correlated. Thus, the extractions with Flavourzyme and Alcalse were a good method to produce a significant amount of amino acids and smaller peptides.
The Effectiveness of Mirror Therapy to Upper Extremity Rehabilitation in Acute Stroke Patients
Rehabilitation is a crucial part of stroke recovery to help them regain use of their limb. The aim of this article was to compare the effectiveness of long-term training of mirror therapy with conventional rehabilitation therapy on neurological and recovery of upper limb in acute stroke patients. In this randomized and assessor-blinded control study, 20 acute stroke patients were analyzed in this study and allocated to a case (n = 10, 50.6 ± 17.90 years) and control group (n = 10, 55.9 ± 11.25 years). All the participants performed daily home exercise during 12 weeks. The patients in the control group were treated with conventional therapy (CT) and a group of cases were treated with mirror therapy (MT) alone program. The outcome measurements were assessed by a therapist blinded assessor using Fugl-Meyer Assessment (FMA) upper extremity score, Brunnstrom recovery stages (BRS), Modified Ashworth Scale (MAS) and Muscle Strength to evaluate upper limb motor function and motor recovery. Data were analyzed using Wilcoxon and Mann-Whitney U tests to compare within-groups and between-group differences. The results revealed that, after 12 weeks of treatment, patients of both groups presented statistically significant improvements in all the variables measured (p < 0.05). Compared with the control group, the patients of the MT group had greater improvement in the proximal movement portion of the FMA upper extremity mean score change (15.8 ± 3.2 versus 10.0 ± 2.7, p = 0.002) while there were no differences in other variables (p > 0.05). There were also no adverse events. It suggests that 12 weeks training of mirror therapy alone was likely to improve the motor recovery of the upper limb and activity of daily living in acute stroke patients than conventional therapy, if treated early.
Mirror Therapy Rehabilitation for Lower Limb of Acute Stroke Patients
This paper aims to study the effectiveness of mirror therapy (MT) having treated to acute stroke patients. The subjects of 20 acute stroke patients, who possessed the ability to respond to verbal instructions were randomly blinded and allocated to a control group (n = 10, 59.2 ± 2.28 years) and a mirror group (n = 10, 53.8 ± 6.14 years). Both groups were treated by intervention of traditional rehabilitation therapy comparing with mirror therapy. Intervention of mirror therapy was taken 60 minutes per day, 5 days per week for 12 weeks. Measures of intervention effectiveness were taken before treatment and after treatment by therapist using Brunnstrom stages, Fugl-Meyer Assessment (FMA) lower extremity score and Brunnel Balance Assessment (BBA) balance. Data were analyzed using independent sample t-test. The results revealed that, after 12 weeks of treatment, subjects of both groups gained statistically significant improvements in all variables measure (p < 0.05). Having compared with the control group, the participants of the MT group had greater improvement on the FMA score (31.0 ± 1.20 versus 28.7 ± 0.58). MT is inexpensive and easily applicable in conjunction with traditional physiotherapy for home care program. Consequently, MT proves to be an effective approach for rehabilitation of patients with post-acute stroke.
Different Chilling-Induced Symptoms and the Underlying Oxidative Stress and Antioxidative Defense in the Exocarp and Mesocarp of Immature Sponge Gourd (Luffa cylindrica) Fruit
Immature sponge gourd fruit is consumed as a vegetable with a limited shelf life. Although cold storage is a simple and powerful tool for maintaining postharvest fruit quality, storage at a low temperature may not be appropriate for vegetables as some chilling injury (CI) of the immature sponge gourd fruit may occur. Therefore, this research aimed to elucidate the relationship between CI, oxidative stress, and the antioxidative defense mechanisms in the exocarp and mesocarp of immature sponge gourd fruit. After storage at 5°C for 6 days, visual CI symptoms, including browning and surface pitting, were found in the peel (exocarp) but not in the mesocarp. There were, however, more dead cells (stained by Evans blue) in the mesocarp of the fruit stored at 5°C. There was a more considerable increase in the electrolyte leakage rate in both fruit tissues held at 5°C than 25°C. The CI was correlated with malondialdehyde (MDA) levels in the tissues. The MDA of fruit exocarp at 5°C was 1.6 fold higher than that at 25°C on day 6, while the lipoxygenase (LOX) activity in mesocarp was 50% higher in fruit stored at a lower temperature. The action of ascorbate peroxidase (APX) was high in the exocarp of the fruit stored at 5°C, but there appeared to be a continuous depletion of the co-substrate or ascorbic acid. In conclusion, the CI in the exocarp was mainly associated with a high level of reactive oxygen species (ROS). In contrast, the CI in the mesocarp appeared to be primarily associated with increased lipid peroxidation by the elevated LOX activity under cold stress compared to storage at 25°C.
Optimization of Hydraulic Retention Time and Organic Loading Rate in Anaerobic Digestion of Squeezed Pineapple Liquid Wastes for Biogas Production
Pineapple wastes are produced in huge amount during the industrial canning process of pineapple; in Thailand over 400,000 tons per annum of canned pineapple exported leaving behind the waste. Besides the pulps and peels as solid wastes, the squeezed pineapple liquid wastes (SPLW) extracted from solid wastes can also be used for anaerobic digestion. In the present study, the anaerobic digestion of liquid squeezed from industrial pineapple peels was carried out using a lab-scale hybrid reactor. The reactor was operated for over 170 days with the hydraulic retention time (HRT) of 20 days decreasing down to 5 days and simultaneous control of organic loading rate (OLR). Under controlled conditions in the hybrid reactor, pH was maintained at 6.5–7.6 by adding alkaline for anaerobic microbial activity. Results showed that the chemical oxygen demand (COD) removal efficiency was at ≥ 90% for all conditions. The biogas production (mL/day) increased thoroughly from longer HRT to shorter HRT, as same as methane production with the maximum values (HRT 5 days, OLR 5 g/COD/ day with recirculation) of 55,130 and 30,322 mL/day, respectively. Moreover, the highest yields of biogas and methane were also investigated under similar conditions with the values of 0.504 and 0.277 L/gCOD, respectively. Interestingly, this optimization of both HRT and OLR of lab-scale anaerobic digestion process could be further practically applied to pilot or industrial scale in canned pineapple factories for biogas production.
Production of Food Flavouring Agents by Enzymatic Reaction and Microbial Fermentation
Rising trends in the consumptions of food flavour compounds lead to motivation in the production of food flavours. The conventional techniques of flavour production are insufficient to produce flavour compounds according to the ascending demands of the market in terms of quantities and varieties. The current flavour production methods utilize chemical synthesis, which can produce a greater numbers of flavours with less time. However, the demand for natural products in consumables have created a necessity for new methodologies to produce flavour compounds with the label of “natural” origin. Emerging techniques in biotechnologies have enabled industries to produce compounds that can be considered natural. This review provides insights into the classification of flavour compounds and their production using microorganisms and enzymes in an ecofriendlier manner. The compounds produced by these techniques can be labelled as “natural” and can increase the market size of food flavours.
Investigation of the Sound Absorption and Transmission Loss Performances of Green Homogenous and Hybrid Luffa and Jute Fiber Samples
In order to promote the use of natural fibers in noise and vibration applications, the properties of these structures should be fully identified. The sound absorption coefficients (SACs) and transmission losses (TLs) of green luffa fiber samples are thoroughly investigated and their acoustic performances are compared with the acoustic performances of green homogenous jute and hybrid jute/luffa fiber samples in this study. For this purpose, green homogenous luffa and jute fiber samples and their green hybrid fiber samples with different thicknesses (10, 20, 30, and 40 mm) are produced and their SACs and TLs are determined using the impedance tube method. First, the methods for the experimental identification of acoustic properties are presented and the variations in the measured acoustic properties are identified. After that, the effects of sample thickness on the acoustic performances of homogenous luffa as well as jute samples and their hybrid fiber samples as a function of frequency are explored. The thickness-dependent tendencies of the SACs and TLs of homogenous and hybrid luffa and jute fiber samples for low, medium and high frequency ranges are determined. Then, the acoustic performances of the homogenous and hybrid luffa and jute samples are compared and evaluated. The results and analyses for the acoustic properties of homogeneous luffa and jute fiber samples and their hybrid fiber samples for a variety of thicknesses and different frequencies presented here can be used to design homogenous as well as hybrid luffa and jute fiber structures in practical applications.
Bi-Template Assisted Sol-Gel Synthesis of Photocatalytically-Active Mesoporous Anatase TiO2 Nanoparticles
Sol-gel mesoporous titanium dioxide powders have been synthesized from chitosan and/or hexadecyltrimethylammonium bromide (HDTMA) and characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA) and N2 adsorption-desorption measurements. The photocatalytic performance of the synthesized meso-TiO2 powders was optimized based on the central composite design (CCD) of methyl orange (MO) degradation under UV light irradiation. The maximum MO degradation was 62.3% over a period of 60 min. Oxides produced using the binary chitosan and HDTMA template (C,H-TiO2) exhibited the relatively higher surface area (99.5 m2/g), smaller crystal size (12.78 nm), narrower band-gap energy (2.92 eV) and higher photocatalytic rate constant (0.0112 min–1) than as those from chitosan (C/TiO2) or HDTMA (H/TiO2) as the template.
Treated Clay Mineral as Adsorbent for the Removal of Heavy Metals from Aqueous Solution
The decontamination of heavy metals present in aquatic bodies is a significant challenge that requires urgent attention. Analytical methods such as BET, XRF, SEM-EDX, and XRD was employed to characterize the raw clay (NT) and acid treated clay (AT). The adsorption of Cr (VI) and Fe (III) onto AT was performed using the batch method. The effects of time, adsorbent dose, temperature, and pH show that the optimal conditions are 50 min, 0.3 g, 35°C, and pH 6. The surface area of AT was 389.37 m2/g, and the adsorption equilibrium time of AT was 50 min. Langmuir isotherms had the best fit. Adsorption capacity is 18.15 and 39.80 mg/g for Cr (VI) and Fe (III) ions, respectively. An increase in area considerably improved the adsorption capacity of AT in the surface specific area. The interaction of Cr (VI) and Fe (III) ions onto AT indicated spontaneous and endothermic reaction. The chromium (VI) kinetic constant (k2 = 1.679) was faster compared to Fe (III) rate constant (k2 = 0.0526). It agreed correctly with the pseudo-second-order equation. The sum square error (SSE) value obtained confirmed the best-fit equations. The percent adsorbed for Cr (VI) and Fe (III) is 74 and 90%. The results revealed that iron has a higher affinity towards AT than chromium. The study revealed that AT could be suitable and effective in the adsorption of chromium and iron in the wastewater medium.
Treatment of Marigold Flower Processing Wastewater Using a Sequential Biological- Electrochemical Process
Agriculture is the mainstay of the Indian economy. The agro-based industries produce high volumes of highstrength wastewaters that need to be treated and reused to prevent environmental pollution and water wastage. This study evaluated the performances of a sequential biological-electrochemical process for treating an anaerobically digested effluent of a Marigold flower processing agro-industry. The uniqueness of this wastewater possess a major challenge to its treatment since not many studies have been conducted on this wastewater. The biological treatment was carried out in a Sequential Batch Reactor (SBR). The treated water was further polished in a Continuous Bipolar-mode Electrochemical Reactor (ECR) to remove the residual organics. The anaerobically digested effluent Chemical Oxygen Demand (COD), Dissolved Organic Carbon (DOC), Total Nitrogen (TN), Total Phosphorus (TP) and Total Suspended Solids (TSS) were 5750 ± 991 mg/L, 980 ± 120 mg/L, 692 ± 60 mg/L, 9.7 ± 1.1 mg/L, and 1144 ± 166 mg/L, respectively. A significant level of treatment was achieved in the SBR. The combined system was able to remove 79% of COD, 85% of DOC, 53% of TN, and almost 100% of TP, TSS, and Volatile Suspended Solids (VSS). Several organic compounds belonging to the category of natural plants compound, pesticide, fungicide, etc. were detected in the raw wastewater. Most of the compounds were almost completely removed by the treatment system. The final effluent was almost colorless and free from suspended solids. However, for reuse, the water needs to be further treated in an advanced oxidation process.
Bioethanol Production by Pichia stipitis Immobilized on Water Hyacinth and Thin-Shell Silk Cocoon
Cell immobilization technique was applied in this study in order to examine effect of immobilized Pichia stipitis TISTR5806 on bioethanol production. Water hyacinth (WH) and thin-shell silk cocoon (CC) were used as cell carriers. Characteristics of the cell carriers were examined to explain the mechanism of bioethanol production. Carrier sizes and weights were optimized to improve bioethanol production. Moreover, stabilities of immobilized cells and carriers were evaluated. Because of high porosity, high surface area and good swelling ability of WH, cell immobilized on 1 g WH with 1 cm length produced the highest ethanol concentration at 13.3 g/L. Five cycles of a repeated batch of immobilized cell (IC) system on WH showed stable performance in ethanol production (8.2–10.4 g/L) with large numbers of the immobilized cells. The interaction between the immobilized cells and the WH surface were discovered.
Mining Bug Report Repositories to Identify Significant Information for Software Bug Fixing
Most studies relating to bug reports aims to automatically identify necessary information from bug reports for software bug fixing. Unfortunately, the study of bug reports focuses only on one issue, but more complete and comprehensive software bug fixing would be facilitated by assessing multiple issues concurrently. This becomes a challenge in this study, where it aims to present a method of identifying bug reports at severe level from a bug report repository, together with assembling their related bug reports to visualize the overall picture of a software problem domain. The proposed method is called “mining bug report repositories”. Two techniques of text mining are applied as the main mechanisms in this method. First, classification is applied for identifying severe bug reports, called “bug severity classification”, while “threshold-based similarity analysis” is then applied to assemble bug reports that are related to a bug report at severe level. Our datasets are from three opensource namely SeaMonkey, Firefox, and Core:Layout downloaded from the Bugzilla. Finally, the best models from the proposed method are selected and compared with two baseline methods. For identifying severe bug reports using classification technique, the results show that our method improved accuracy, F1, and AUC scores over the baseline by 11.39, 11.63, and 19% respectively. Meanwhile, for assembling related bug reports using threshold-based similarity technique, the results show that our method improved precision, and likelihood scores over the other baseline by 15.76, and 9.14% respectively. This demonstrate that our proposed method may help increasing chance to fix bugs completely.
D-Optimal Design Optimization for the Separation of Oleic Acid from Malaysian High Free Fatty Acid Crude Palm Oil Fatty Acids Mixture Using Urea Complex Fractionation
Oleic acid (OA) rich vegetable oils is important for the daily essential dietary oils intake but restrict to particular oil such as olive oil. However OA enrichment to other vegetable oil such as palm oil is always possible. OA can be obtained from cheap resources such as high free fatty acid crude palm oil (HFFA-CPO). OA concentrate from HFFA-CPO fatty acids mixture requires efficient and low cost technique. Urea complex crystallization fractionation is a classic method for fractionating saturated and monounsaturated fatty acids from polyunsaturated fatty acids of many vegetable oils. In this work, the separation and purification of oleic acid (OA) from unsaturated fatty acids mixture fraction (USFA) of HFFA-CPO fatty acids mixture by urea complex fractionation (UCF) was studied. The crystallization reaction conditions of urea inclusion for the non-urea complex fraction (NUCF) were optimized using the response surface methodology (RSM) and the optimal model was developed. The results showed high content of OA (88%) in urea complex fraction (UCF) with 86% yield at optimal conditions of urea-to-USFAs ratio of 4.62 : 1 (w/w), crystallization temperature at –10°C and crystallization time of 24 h. The results have demonstrated that urea complex crystallization fractionation method is a very effective with low cost, stable, obtainable, and comparatively ease to recover of OA from polyunsaturated fatty acids (PUFA) of an oil fatty acids mixture. Pure OA is plausible to be used back for the OA enrichment modification into palm oil for new dietary oil.
A Comprehensive Review on the Drying Kinetics of Common Tubers
Sun-drying has been conventionally used in the production of tuber-derived commodities such as cassava, potato, sweet potato, and yam. Recent developments in the drying process involves the use of different drying equipment to improve quality and profitability. The importance of drying parameters in the operation of drying equipment necessitates drying kinetic studies on common tubers. This article aims to review the drying kinetics studies conducted on common tubers. Particular interest is on the effect of the drying process parameters like temperature and velocity of heating air medium, the physico-chemical pretreatment method, and sample preparation on the drying rate and time. The different best fit drying kinetic models for specific tubers have also been extensively studied. The role of drying process parameters and best fit model equations on the design of the drying equipment has been emphasized.
Explicit Formulas of ARL on Double Moving Average Control Chart for Monitoring Process Mean of ZIPINAR(1) Model with an Excessive Number of Zeros
Usually, the performance of control charts are widely measured by average run length (ARL). In this paper, the derivative explicit formulas of the ARL for double moving average (DMA) control chart are proposed for monitoring the process mean of zero-inflated Poisson integer-valued autoregressive first-order (ZIPINAR(1)) model. This model is fit when there are an excessive number of zeros in the count data. The performance of the DMA control chart is compared with the results of moving average and Shewhart control charts by considering from out of control average run length (ARL1). The numerical results found that the DMA control chart performed better than other control charts in order to detect mean shift in the process. In addition, the real-world application of the DMA control chart for ZIPINAR(1) process is addressed.
Numerical Modeling for Corrosion Rate between Heat-affected Zone and Unaffected Base Metal of Galvanized Steel Welded by Brazing
Brazing of galvanized steel causes decaying of the zinc coating and decreasing of corrosion resistance on heat-affected zone (HAZ) and weldment. The corrosion rates among the HAZ, unaffected base metal (UBM), and weldment of galvanized steel welded by brazing were numerically modeled by COMSOL Multiphysics. The numerically modeled current density values from various zones, such as the couples between the HAZ and the UBM, between the weldment and the HAZ, and between the UBM and steel were used to calculate the corrosion rates. In this work, two different methods based on Faraday’s Law, the mixed potential theory and the Numerical modeling, were compared for calculations of the corrosion rates of each region. Using the mixed potential theory, the calculated corrosion rates of regions I, II, III, IV, V and VI were 0.853, 0.284, 2.105,1.754, 2.028 and 0.554 mm/y, respectively. Where as based on the Numerical modeling, these rates of all regions were 0.918, 0.275, 2.198, 1.904, 2.151, and 0.566 mm/y, in orderly. These comparisons suggested that the corrosion rates obtained from the two methods were similar. However, the results showed that the Numerical modeling method could predict the corrosion rate with less error.
Enhancement of PHB Production Process in a Fed-Batch Bioreactor Using Input-Output Linearization Technique with Optimal Setpoints
Polyhydroxy butyrate (PHB) is a polyester that has been widely applied to formulate bioplastics. A challenge for the PHB production is the enhancement of PHB accumulation in bacterial cells, which can be conducted through the nutrient feeding strategy. A control system based on an input/output (I/O) linearization technique for the PHB production in a fed-batch bioreactor is proposed in this work. The concept of feast/famine phase is employed to provide the optimal desired targets for each time instant through optimization problems. The developed controller is applied to regulate the controlled output to follow the desired setpoints by manipulating the feed flow rate of nutrients. Simulation results show that the proposed control system attempts to follow the optimal desired targets (discrete-time approach) during the process operation. The accumulation of PHB in bacterial cells is around 25% higher than that of the process with a modified PI controller. Control performance tests indicate that the proposed control strategy successfully regulates the process according to the desired targets and handles the process disturbance effectively.
Corrosion Behaviour of AISI409 Stainless Steel with Al Slurry Coating in Molten Salt
A concentrated solar power plant produces electricity by collecting thermal energy from sunlight. Then the thermal energy is stored in the heat transfer fluid (HTF). The most widely used and studied HTF is solar salt (60wt%NaNO3–40wt%KNO3) that achieves the most requirements of HTF. However, at high temperatures, the corrosion is still violent for most materials, thus the material selection is important. This research aims to investigate the feasibility for application of AISI 409 ferritic stainless steel as containers of the molten salt. AISI 409 is suitable for high temperature usage, and more economical than other grades which have higher chromium. To investigate the corrosion resistance in molten salt, AISI 409 samples were coated by dipping in Al slurry. Then they were heated up to 400°C to remove binders. The coatings with Fe-Al intermetallic and alumina layers were formed after binder removal and subsequently annealing at 700°C for 3 h in the air atmosphere. This research reported the corrosion behaviour of Al coated and uncoated samples which had been treated by immersion in molten salt at 500°C for 100 h with analysis results. The results demonstrated that weight and thickness of uncoated samples were increased due to formation of the oxide layers such as Fe2O3 and Fe3O4 on the surfaces. For the Al coated samples, the weight and thickness of the coat layers were massively decreased after being immersed in molten salt at the first 1 h due to removal of Al-O, slag or impurity in the coating. Nevertheless, the weight increased gradually until 100 h. The oxidation of the Fe-Al intermetallic layer exhibited about 35% slower oxidation than that of uncoated samples, thus the coating technique has potential to be applied against molten salt.
Application of Statistical Solvent Mixture Design in Optimizing the Solid-Liquid Extraction of Phenolic Compounds from Mango Seed Kernels
Mango seed kernel (MSK) is a waste material of the mango processing industry and is reported to significantly contain phenolic compounds with anti-oxidative properties. In this work, these compounds are isolated via solid-liquid extraction (SLE) in which solvent mixture design approach was used to evaluate the optimal quaternary solvent ratio in relation to the phenolics content of extracts from MSK. The quaternary solvent is composed of ethanol (E), methanol (M), acetone (A), and water (W). The extraction process was implemented at 40°C for 60 minutes with the ratio between solid and solvent at 1:25. Response surface methodology coupled with simplex lattice design was developed to evaluate the optimal solvent system and their interaction effects on the phenolic compounds content. The linear, two-way, and three-way interaction, except for methanol-acetonewater system, resulted in positive effects on the phenolic compounds content. The response model shows that a quaternary mixture with approximately 3:3:3:1 E:M:A:W ratio provided the highest phenolic content. A Scheffé cubic model sufficiently described the extraction process. The results of this study showed that the extraction of phenolic compounds in MSK via SLE using a mixture of solvents is possible. Higher extraction efficiencies can be achieved by optimizing the SLE process, and the optimum conditions can be applied to produce phenolic extracts with positive antioxidant activity.
Modification of Waste Leather Trimming with in Situ Generated Silver Nanoparticles by One Step Method
Waste leather trimming (WLT) was modified by in situ generation of silver nanoparticles (AgNPs) and silver oxide nanoparticles (Ag2ONPs) by one step thermal assisted method. The modified WLT was analyzed by FTIR, SEM, EDS, XRD and TGA techniques and antibacterial analysis. The generated silver based nanoparticles had a mean size of 93 nm. The FTIR spectra revealed no major changes between WLT and modified WLT. The XRD studies indicated additional peaks in the diffractogram of modified WLT which belonged to AgNPs and Ag2ONPs. The unmodified WLT had four inflection temperatures at 89, 303, 454, and 785°C while these values for the modified WLT were 84, 211, 305, and 328°C indicating a slight lowering of thermal stability due to the catalytic activity of the generated silver based nanoparticles. Further, the modified WLT formed the inhibition zones against E.coli, P.aeruinosa, S.aeureus and B.lichinomonas bacteria with diameters of 33, 36, 29, and 30 mm respectively. Hence, the modified WLT can be considered as filler for making low cost antibacterial biocomposites.
Binary Integer Programming Approach to Optimal Content Placement in Cloud-based Content Delivery Networks
Over the last decades, Content Delivery Networks (CDNs) have been developed to overcome the limitation of user perceived latency by replicating contents from origin server to its content servers around the globe close to clients. As some contents occupy most of the storage capacity and processing power in traditional private content servers, cloud computing can provide a pool of storage and processing power resources for caching contents. By adopting cloud computing to CDN, the content provider can use the cloud infrastructure by distributing the contents to cloud servers which will then deliver to near clients. In this paper, we propose a cloud-based CDN framework designed by two schemes 1) UDP/TCP-based content distribution from origin server to cloud servers and 2) SDN-based cloud server coordination. In addition, we also formulate the optimal content placement problem using binary integer programming to minimize the total cost of renting resources including storage, processing power, and network bandwidth in cloud providers for hosting contents from origin server. Then, the optimal solution obtained from binary integer programming is evaluated by greedy algorithm and simulations. The proposed framework helps content provider to offer high quality of services to clients while minimizing the cost of rented cloud resources.
Evaluation of Eutrophication State of Mae Kuang Reservoir, Chiang Mai, Thailand by Using Carlson’s Trophic State Index
Eutrophication is an event that occurred when the lakes have a high growth rate of phytoplankton and causing deterioration of water quality. In this work, we use Carlson’s Trophic State Index (CTSI) to evaluate the situation of eutrophication of Mae Kuang Reservoir for the first time. Three parameters, i.e., total phosphorus, chlorophyll-a, and water transparency were used to calculate CTSI. The results showed that the reservoir has started to be eutrophic. In June and October, the ranges of the CTSI were 49.26–59.60 and 49.07–56.04, respectively, which indicated a low eutrophic state of the reservoir. However, in this primary eutrophic condition, the water quality was not bad, and the living organisms can survive. The CTSI is a valuable and simple alternative method for monitoring and estimating lake ecosystems' eutrophic status.
Effective Data Augmentation and Training Techniques for Improving Deep Learning in Plant Leaf Disease Recognition
Plant disease is the most common problem in agriculture. Usually, the symptoms appear on leaves of the plants which allow farmers to diagnose and prevent the disease from spreading to other areas. An accurate and consistent plant disease recognition system can help prevent the spread of diseases and save maintenance costs. In this research, we present a plant leaf disease recognition system using two deep convolutional neural networks (CNNs); MobileNetV2 and NasNetMobile. These CNN architectures are designed to be suitable for smartphones due to the models being small. We have experimented on training techniques; online, offline, and mixed training techniques on two plant leaf diseases. As for data augmentation techniques, we found that the combination of rotation, shift, and zoom techniques significantly increases the performance of the CNN architectures. The experimental results show that the most accurate algorithm for plant leaf disease recognition is NASNetMobile architecture using transfer learning. Additionally, the most accurate result is obtained when combining the offline training technique with data augmentation techniques.
Natural and Synthetic Antioxidants Prevent the Degradation of Vitamin D3 Fortification in Canola Oil during Baking and In Vitro Digestion
Vitamin D insufficiency is widespread in the northern and partly equatorial hemisphere countries. Fortification of vitamin D in commonly consumed vegetable oils can prevent rickets in children, osteoporosis and bone fractures in adults. Avoiding the loss of vitamin D3 fortification in oils during cooking is beneficial for consumer’s health. The aim of this work was to investigate the stability of cholecalciferol (vitamin D3) fortification in canola oil during baking at 80 to 230°C for 10 to 40 min. The natural antioxidants (β-carotene and α-tocopherol) and the synthetic ones (butylated hydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ)) were used to prevent the degradation of vitamin D3. The kinetic degradation of vitamin D3, oxidative status of canola oil and the bioaccessibility in in vitro digestion were assessed. Vitamin D3 was relatively stable at 80 and 130°C for 10 to 40 min. High temperatures of 180 and 230°C caused the highest loss of vitamin D3 being up to 90%. Reaction rate of vitamin D3 degradation ranged from 2.01 to 6.80 × 10–2 sec–1. BHT and TBHQ had the highest antioxidant activity (> 50 %) to decrease the degradation of vitamin D3 at 230°C. The oxidative status (peroxide value, malondialdehyde content) of canola oil was improved after incorporating antioxidant agents. The vitamin D3 bioaccessibility was increased 1.5 fold after in vitro digestion. The consumption of 5 g brownie containing vitamin D3 100 μg/L and antioxidant agents 180 mg/L in 1 mL of canola oil would cover the daily intake.
Hot Forging Process Design and Initial Billet Size Optimization for Manufacturing of the Talar Body Prosthesis by Finite Element Modeling
In hot forging industry, the process design and the billet size determination are very crucial steps because those steps directly influence both the product quality and material utilization. The purpose of this paper was to propose a technique used to design the hot forging process for the manufacturing of the talar body prosthesis. The talar body prosthesis is one of the artificial bones, which its geometry is a free form shape. In this study, the Finite Element Modeling (FEM) was used as a tool to verify the proposed design before implementation in a production line. In addition, an initial billet was determined the optimum size in the FEM by varying the mass ratio factor, the diameter, and the length. It was found that the mass ratio factor is a very useful guideline since the optimum size is quite close to the provided size from the guideline. The FEM results showed that the dimensions of the initial billet significantly affect the complete metal filling in the die cavity. Moreover, the optimum size between the diameter and length can reduce the material waste in the hot forging process of the talar body prosthesis. Finally, the experimental results of the hot forging process showed that the proposed process design with the optimum size of the initial billet is achieved in order to manufacture the talar body prosthesis and the material utilization of the new proposed process is improved from the traditional process by 2.6 times.
Photocatalytic Degradation of Diazinon in g-C3N4/Fe(III)/persulfate system under Visible LED Light Irradiation
In the past years, the non-conventional treatment of pesticides in wastewater like photocatalytic degradation has been the focus of the attention of researchers to mitigate its impact on both humans and the environment. In this study, synthesized graphitic carbon nitride (g-C3N4) from urea is used in the photocatalytic degradation of diazinon as a photocatalyst with the addition of ferric nitrate (Fe3(NO3)3) and potassium persulfate (K2S2O8) to enhanced degradation. Graphitic carbon nitride was produced using direct calcination of urea at 550°C for 2 h. The physicochemical properties of the synthesized g-C3N4 were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and X-ray Diffractometer (XRD). The photocatalytic degradation of diazinon was conducted under a g-C3N4/Fe(III)/persulfate system using different parameters such as catalyst loading (75, 100, and 125 mg), Fe3(NO3)3 (325, 350, and 375 mg L–1), and K2S2O8 (275, 300, and 325 mg L–1) resulting to an improved photocatalytic degradation efficiency. The physicochemical results showed a synthesized g-C3N4 that exhibits properties that are following the international standards. The results of photocatalytic degradation showed the highest degradation of g-C3N4 at 37.3%, under the parametric conditions of 125 mg g-C3N4, 325 mg L–1 of Fe3(NO3)3, and 300 mg L–1 of K2S2O8. The degradation efficiency was observed to increase as the catalyst load increases, while an increase in degradation efficiency can only be observed up to a certain value using ferric nitrate and persulfate. Overall, this study provided insight on the possible use of urea, as a source of g-C3N4 and the use of g-C3N4 as a photocatalyst using visible light as a more economic approach and cost-efficient way of handling wastewater.
Application of Chitosan in Plant Defense Responses to Biotic and Abiotic Stresses
Chitosan, a copolymer of N-acetyl-D-glucosamine and D-glucosamine, which possesses properties that make it useful in various fields, is produced by the deacetylation of chitin derivatives. It is used in agriculture as a biostimulant for plant growth and protection, it also induces several responsive genes, proteins, and secondary metabolites in plants. Chitosan elicits a signal transduction pathway and transduces secondary molecules such as hydrogen peroxide and nitric oxide. Under biotic stress, chitosan can stimulate phytoalexins, pathogenesis-related proteins, and proteinase inhibitors. Pretreatment of chitosan before exposure to abiotic stresses (drought, salt, and heat) induces plant growth, production of antioxidant enzymes, secondary metabolites, and abscisic acid (ABA). It also causes changes in physiology, biochemistry, and molecular biology of the plant cells. However, plant responses depend on different chitosan-based structures, concentrations, species, and developmental stages. This review collects updated information on chitosan applications, particularly in plant defense responses to biotic and abiotic stress conditions.
Optimization of Partial Epoxidation on Jatropha curcas Oil Based Methyl Linoleate Using Urea-hydrogen Peroxide and Methyltrioxorhenium Catalyst
Natural epoxy fatty acids such as Coronaric acid (9,10-epoxy-12Z-octadecenoic acid) and vernolic acid (12,13-epoxy-9Z-octadecenoic acid) are rich in of Vernolia galamensis, Vernolia anthelmintica and Chrysanthemums coronanium. The two fatty acids each contains an oxirana ring and a double bond C = C. The oil or its derivatives are suitable for industrial usage as reactive diffluent of alkyd resins, plasticizers and stabilizers, surface coatings, surfactants and lubricants, as intermediates in chemical reactions for making linear epoxides of composite materials and polymers. However, the use of such oils on an industrial scale is impossible due to limited resources. Therefore, epoxidation reactions need to be carried out to overcome the demand for partial epoxide fatty acids. Partially epoxidation of methyl linoleate at room temperature (30°C) in the presence of pyridine, methyltrioxorhenium (MTO) as catalyst and urea-hydrogen peroxide (UHP) as oxidant was studied by using response surface methodology (RSM). A five-level-four-factors central composite rotatable design (CCRD) was used to optimize the partially epoxidation conditions and study the effect of MTO, UHP, pyridine and reaction time on relative conversion to oxirane (RCO). Quadratic polynomial model was employed to generate response surface plots for RCO. At optimal condition, 79.05% monoepoxide was formed at the RCO of 58.15% under condition of 0.75 mol% mole ratio of MTO, 300 mol% mole ratio of UHP and 9 mol% of pyridine at 120 min reaction time. It can be concluded that the effect of UHP mole ratios was the dominant factor to control the degree of partial epoxidation of methyl linoleate followed by mole ratio of MTO, reaction time and mole ratio of pyridine to formed methyl 12,13-epoxy-9Z-octadecenoate or/and methyl 9,10-epoxy-12Z-octadecenoate.
Evaluation of Forging Die Defect by Considering Plastic Deformation and Abrasive Wear in a Hot Forged Axle Shaft
In the hot forging process, an abrasive wear is a major problem in the manufacturing process which may possibly happen together with the plastic deformation. Both effects are difficult to distinguish in the real tooling. Finite Element Modeling (FEM) is a tool that use to simulate those phenomena in the hot forging process. However, some unknown factors are not directly obtained from the actual measurement. Thus, the sensitivity analysis is applied together with FEM to approximate those parameters. This research was to evaluate the die defects of the hot forged axle shaft process which were the plastic deformation and the abrasive wear. The reliable simulation modeling was developed by conducting the sensitivity analysis of the unknown parameters; heat transfer and friction coefficient, and compared the results with the experimental results. Then, the evaluation of the defects was performed by considering the effect of the plastic deformation and abrasive wear separately. The plastic deformation would be determined by comparing the effective stress with the yield strength of the die material at the same temperature. To predict abrasive wear in 3D space the die profile from the actual process was measured by CMM and then it was compared with that obtained by FEM. Archard’s model was used to predict the abrasive die wear in FEM. The variation of the K-values was significant to the wear prediction. According to this study, the average K-value obtained from different positions gives the best representative than considering only a single point K-value.
Feasibility of Using Natural Rubber (NR) Latex Foam as a Soft Robotic Finger: Role of Foaming Agent in Morphology and Dynamic Properties of NR Latex Foam
Sarcopenia caused by ageing and muscle loss is mostly found in the elderly people. Since a number of older people have been increased, a device which assists with grasping can play an important role in an ageing society. The purpose of this research is to select the material which is potentially a part of soft robotic actuator. Natural rubber (NR) latex produced locally in Thailand is intentionally chosen and chemically vulcanized by using a conventional vulcanization system into a molded fingered foam. The research focuses on varying the amount of foaming agent (Benzene sulfonyl hydrazide, BSH). Effect of foaming agent quantity on morphology and dynamic properties of the prepared natural rubber foam was elucidated. The suitable foam formula is selected and molded as the human fingers in the structure of a potential soft robotic actuator which were tested for the movement.
A Modified Strain-displacement Method for High Accuracy 8-Node Solid Finite Element
Higher-order three-dimensional solid elements are widely used for machine design and structural analyses. Although higher-order solid elements offer higher accuracy, the assembly routines often consume large amount of computational time and memory usage. In contrast, lower-order solid elements such as an 8-nod are simpler in programming implementation and consume less computational resources. However, they can produce problems of locking phenomena e.g. membrane and shear locking. Moreover, in a three-dimensional analysis using continuum solid elements, it is necessary to consider the stresses in the through-thickness direction, for example, in layered soil and foundation. This research aims to develop a modified strain-displacement finite element formulation that eliminates locking problems and generally applicable to both thick and thin threedimensional structures. The proposed formulation is based on the key concept of energy equivalence mapped between the global and natural curvilinear coordinates. The advantage of the proposed method is the ability to select a set of chosen strain functions that can be defined arbitrarily on the natural curvilinear coordinates.
The Performance of CUSUM Control Chart for Monitoring Process Mean for Autoregressive Moving Average with Exogenous Variable Model
The objective of this study was to derive explicit formulas for the average run length (ARL) of an autoregressive moving average with an exogenous variable (ARMAX(p,q,r)) process with exponential white noise on a cumulative sum (CUSUM) control chart. To check the accuracy of the ARL derivations, the efficiency of the proposed explicit formulas was compared with a numerical integral equation (NIE) method in terms of the absolute percentage error. There was excellent agreement between the two methods, but when comparing their computational times, the explicit formulas only required 1 second whereas the NIE method required 599.499–835.891 s. In addition, real-world application of the derived explicit formulas was illustrated using Hong Kong dollar exchange rates data with an exogenous variable (the US dollar) to evaluate the ARL of an ARMAX (p,q,r) process on a CUSUM control chart.