Applied Science and Engineering Progress

Process Modelling and Optimization of Palm Oil Biodiesel Production Using Aspen Plus and Response Surface Methodology

Babu Dharmalingam — 2026-06-10

Formulation and Characterization of Rosin-Based Bioresins Modified with Palm Wax, Microwax, and Olein for Sustainable Biocomposite Applications

Siti Agustina — 2026-04-28

The formulation of sustainable bioresins sourced from renewable materials generates considerable opportunities for biocomposite uses in sectors such as food, packaging, and cosmetics. This research focused on the formulation and characterization of rosin-based bioresins that were modified with palm wax, microwax, and olein at various concentrations (5%, 10%, and 15%). The bioresins were formulated by melting rosin and subsequently adding additives, followed by casting and cooling processes. The analysis using Fourier-transform infrared spectroscopy (FTIR) verified the presence of functional groups associated with the resin’s esterification and the addition of additives. The assessment of thermal stability was performed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), which indicated distinct degradation phases that were affected by the type and concentration of the additives. DSC revealed distinct melting temperatures (Tm) ranging from 40 to 90 °C and glass transition temperatures (Tg) from 60 to 230 °C. TGA showed degradation onset temperatures (Td) between 370 and 410 °C, indicating excellent thermal stability across all formulations. Hardness testing demonstrated composition-dependent mechanical reinforcement, with B-series and C-series presenting improved resistance compared to A-series. The combined thermal–mechanical evaluation demonstrates that bioresin B provides the most balanced performance due to synergistic contributions of microcrystalline wax, yielding improved hardness (13.12 ± 10.43 kg in B₂) while maintaining high thermal stability (Td = 390 °C). These findings highlight the potential of modified bioresins as sustainable alternatives with tunable structure–property relationships suited for packaging films, protective coatings, and solid cosmetic matrices. Thermal analysis indicated enhanced stability in systems modified with palm wax and microwax, while olein contributed to an increase in flexibility at the expense of thermal resistance. Overall, modified bioresin B emerged as the optimal formulation for structural and packaging applications due to its superior thermal stability, increased hardness, and enhanced molecular interactions.

Nanomaterials in Construction and Architecture: Cross-Scale Performance, Risks, and Implementation Limits

Djamil BenGhida — 2026-04-08

Nanomaterials are increasingly investigated for their potential to enhance the mechanical performance, durability, energy efficiency, and environmental functionality of construction materials and architectural systems. This paper presents a critical, cross-scale synthesis of nanomaterial applications in structural composites, building envelopes, and urban-scale interventions, examining both reported performance gains and implementation constraints. An evaluative synthesis approach is adopted rather than quantitative ranking, reflecting the heterogeneity of testing protocols and the predominance of laboratory-scale evidence, with comparatively limited validation at pilot or field scales. Reported benefits include improvements in mechanical and structural performance, enhanced durability and material longevity, advances in thermal and energy performance, environmental and air-quality functions, gains in resource efficiency and material optimization, expanded design and system integration potential, and localized urban-scale and system-level contributions. However, these outcomes remain highly context-dependent and are shaped by production pathways, cost structures, durability uncertainties, and potential health and environmental risks across the material lifecycle. By situating nanomaterials within integrated, lifecycle-oriented design and governance frameworks, the findings indicate that their greatest contribution lies in context-sensitive, system-level deployment rather than in isolated technological fixes often associated with techno-solutionism.

A Dynamic Cost Estimation Framework for Customized Manufacturing: A Case Study of the Ambulance Assembly Industry

Athakorn Kengpol — 2026-01-08

The customized manufacturing industry faces a major challenge in achieving accurate and rapid cost estimation. The difficulty arises from product complexity and diverse data generated across multiple departments. This often results in scattered and outdated information that causes operational delays and reduces competitive advantage. The study proposes an Engineering Framework for Dynamic Cost Estimation through data integration with Power BI serving as the core platform. The framework was implemented and validated through a case study in the ambulance assembly industry, which represents a highly complex manufacturing sector. The quantitative results show that the proposed framework reduces the time required for ambulance type determination by 54.7% and decreases cost estimation time by 61.6%. These improvements address the specific challenges identified in the case study and also enhance overall operational efficiency. The findings provide a significant contribution to the advancement of manufacturing engineering. The research also delivers a validated model and knowledge that can be adapted to improve efficiency in other customized manufacturing sectors.

Development of Kimpul Starch-Based Composite Films Reinforced with TEMPO-Oxidized Cellulose Microfiber for Food Packaging

Fadlan Hidayat — 2026-04-02

This study investigated the development of starch-based films reinforced with TEMPO-oxidized cellulose microfibrils (TOCMF) using kimpul starch as the primary polymer matrix. A Box Behnken Design (BBD) combined with Response Surface Methodology (RSM) was employed to evaluate the effects of starch, TOCMF, and glycerol contents on the mechanical properties (tensile strength (TS) and elongation at break (EAB)). The quadratic models were statistically significant with high coefficients of determination (R² = 0.86–0.98) and non-significant lack-of-fit, confirming their adequacy for prediction and optimization. The optimized film formulation achieved superior mechanical properties, with TS (38.78 MPa) higher than most previously reported starch-based films, while maintaining desirable flexibility (EAB = 18.59%). This work highlights the potential of underutilized kimpul starch incorporated with TOCMF to develop packaging films with superior functional performance, providing new insights into the design of sustainable materials for food packaging applications. Moreover, the use of kimpul, a low-cost and locally abundant tuber, offers an additional advantage by promoting value-added utilization of indigenous resources for environmentally friendly packaging.

Effect of Chitosan and Titanium Dioxide Coatings with and without UV Activation on the Postharvest Quality of ‘Nam Dok Mai Si Thong’ Mango

Simona D'Angelo — 2026-04-28

This study aimed to assess the individual and combined effects of chitosan and titanium dioxide (TiO₂), with and without UV exposure, on delaying ripening, reducing weight loss, and maintaining postharvest quality of mangoes stored at 25 ± 2 °C for up to 12 days. The evaluation focused on changes in physicochemical properties, antioxidant content, in vitro antioxidant activity, and microbial decay. The coating treatments included: 1) control (C), 2) chitosan (CH), 3) CH–TiO₂ (CT), 4) control with UV activation (C-UV), 5) CH with UV activation (CH-UV), 6) CT with repeated UV activation (CT-UV), 7) CT with single UV activation (CT-UV1). CT coatings effectively reduced ethylene production (0.19–0.29 μL/kg.h) and respiration rate (50–78 mg CO₂/kg.h), thereby slowing ripening compared to the control. UV activation did not significantly enhance the suppression of ethylene production or respiration. CT coatings also minimized weight loss (8.34–8.47% vs. 12.62% in C), maintained peel color stability, and better preserved physicochemical properties. In addition, CT coatings delayed the decline in titratable acidity (0.18–0.56% on day 12) and slowed the accumulation of total soluble solids (14.75–14.88 °Brix on day 12). Moreover, antioxidant retention was also improved, as indicated by higher total phenolic content (34.65 mg GAE/g) and FRAP values (110.26 μg TE/g). CT-treated mangoes exhibited the lowest incidence of decay (7.57–7.71%), highlighting the antimicrobial potential of TiO₂ and supporting its use as an effective strategy to extend the shelf life of mangoes.

Green Synthesis of Mesoporous TiO₂ Nanoparticles via Colocasia esculenta L. Leaf Extract: Influence of Calcination Temperature on Physicochemical Properties

Linda Jati Kusumawardani — 2026-04-07

TiO₂ nanoparticles were successfully synthesized using Colocasia esculenta L. leaf extracts (TiO₂–CELEs) and calcined at various temperatures (300–600 °C). Among the samples, TiO₂–CELEs 400 (400 °C) and TiO₂–CELEs 500 (500 °C) exhibited outstanding photocatalytic activity, achieving nearly complete degradation of methylene blue under light irradiation. TiO₂–CELEs 400 showed the largest surface area (106.31 m²/g) with well-developed mesopores, resulting in enhanced adsorption capacity. In contrast, TiO₂–CELEs 500 demonstrated superior photocatalytic performance despite its lower surface area, primarily due to its higher crystallinity, which facilitated more efficient charge separation and suppressed electron–hole recombination. X-ray diffraction (XRD) analysis revealed that increasing the calcination temperature enlarged the crystallite size (5.22–18.11 nm) and crystallinity (71.50–82.80%). Diffuse reflectance spectroscopy (DRS) indicated band gap narrowing from 3.25 to 3.10 eV, signifying the onset of the anatase–rutile phase transition. Brunauer–Emmett–Teller (BET) analysis confirmed mesoporous characteristics with an unusual desorption-over-adsorption pattern, suggesting flexible pores that facilitate molecular diffusion. Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS) confirmed the morphology and high purity of the nanospheres, with only minor potassium residues from CELEs metabolites. Overall, optimizing the calcination temperature effectively balanced surface area and crystallinity, establishing CELEs as a promising, eco-friendly biotemplate for developing high-performance TiO₂ photocatalysts applicable to photocatalysis, dye–sensitized solar cells, medical and environmental remediation.

Improved Photocatalytic Activity of TiO₂ through MnFe₂O₄/Chitosan–Alginate Doping for Procion red MX-5B Degradation and Ecotoxicity Evaluation

Poedji Loekitowati Hariani — 2026-03-05

The development of photocatalytic materials for organic pollutant degradation has continued to advance. In this study, a MnFe₂O₄/Chitosan–Alginate@TiO₂ composite was synthesized, in which magnetic MnFe₂O₄ was encapsulated within a chitosan–alginate polymer matrix and doped with TiO₂. The composite’s crystal structure, morphology, elemental composition, optical, and magnetic properties were characterized using XRD, SEM–EDX, UV–DRS, and VSM analyses. Optimization of Procion Red MX-5B (PRD) dye degradation was performed using Response Surface Methodology (RSM), with PRD concentration, pH, and irradiation time as independent variables. The composite exhibited strong magnetic behavior (magnetic moment: 44.63 emu/g) and a narrow band gap (2.20 eV). The photocatalytic degradation followed a quadratic model, with all variables showing significant effects (p-value < 0.05). The predicted optimal conditions, which include a PRD concentration of 45 mg/L, pH 3.3, and 59 min of irradiation time, resulted in a measured degradation efficiency of 99.71%. The composite demonstrated excellent stability after six recycling cycles. TOC removal of 84.30% confirmed substantial mineralization into inorganic compounds, such as CO₂ and H₂O, while ecotoxicity tests using green gram seeds germination indicated that the degradation products were non-toxic.

Improving Anaerobic Co-Digestion Performance using Granular Activated Carbon for Enhanced Methane Production: A Case Study of Food Waste and Tofu Wastewater

Farida Hanum — 2026-02-23

The rapid depletion of conventional energy resources and global population growth have intensified the need for sustainable alternative energy sources, with biogas technology emerging as a promising solution. This study investigated co-digestion of food waste (FW) and tofu wastewater (TWW) for methane production and evaluated the effect of granular activated carbon (GAC) on process performance. Among FW:TWW ratios tested (1:2, 1:3, 1:4), the 1:3 mixture achieved the highest performance, with peak daily methane production of 124.04 ± 0.83 mL/gVS, cumulative methane yield of 278.53 ± 1.08 mL/gVS, and COD removal of 77.78 ± 0.31%. Supplementing the 1:3 mixture with 10 g/L GAC further improved methane generation, increasing peak daily methane production by 21.42 ± 0.56%, VS degradation by 6.84 ± 0.40%, and COD removal by 15.56 ± 0.77% relative to the control. Enhanced performance is attributed to improved microbial activity via direct interspecies electron transfer (DIET) and biofilm development on GAC surfaces. SEM confirmed the presence of biofilms on post-digestion GAC. BET analysis indicated mesoporous characteristics suitable for microbial colonization (type IV isotherms with H2-type hysteresis loops), with a specific surface area of 803.2 m²/g, pore volume of 0.583 cc/g, and mean pore diameter of 2.907 nm. These findings demonstrate that GAC-assisted co-digestion can strengthen methane productivity and organic removal, supporting broader advancement of sustainable waste-to-energy strategies.

In Silico Exploration of the Antimicrobial Potential of Diospyros-Derived Bioactives Against Acinetobacter baumannii

Soundaryalakshmi Ramesh — 2026-04-09

Antimicrobial Resistance (AMR) is a major health threat in the 21^st century, driven by the growing number of resistant infections and the lack of new antibiotics. Without effective measures, AMR could become the leading cause of death by 2050. Among the WHO-identified ESKAPE pathogens, Acinetobacter baumannii is of particular concern due to its ability to evade antibiotic treatment. Notably, carbapenem-resistant A. baumannii (CRAB), driven mainly by overexpression of OXA-23 class D β-lactamase, is associated with prolonged hospital stays and high mortality, making it a top priority for antibiotic research. The lack of effective treatments also increases risks in surgery and chemotherapy. These challenges highlight the need for alternative strategies, with phytochemicals recently gaining attention as promising candidates for combating AMR. Accordingly, a combination of computational pipelines and emerging machine learning–based algorithms was applied to perform a structured investigation of phytochemicals with antibacterial potential. Therefore, this study investigates the potential of the genus Diospyros against CRAB, where a total of 448 compounds were retrieved from the Indian Medicinal Plants, Phytochemistry and Therapeutics 2.0 (IMPPAT 2.0) database, of which 135 unique molecules were docked against OXA-23. Machine learning–based scoring refined the results to 20 leads, and ADMET analysis identified Diosindigo B as the most promising candidate with favorable pharmacokinetics, drug-likeness, and low toxicity. The compound was further analyzed using interaction studies, scaffold analysis, and molecular dynamics (MD) simulations. Overall, Diosindigo B shows potential as a therapeutic candidate against CRAB; however, experimental validation is required to confirm its efficacy.

NaOH-Activated Carbon from Gnetum gnemon L. Shell Waste for Methylene Blue Adsorption from Aqueous Solutions

Lelifajri — 2026-02-24

Synthetic dyes, such as methylene blue (MB), are widely used in textile and related industries, and their discharge into aquatic environments poses severe environmental and health risks due to their toxicity, persistence, and poor biodegradability. This study reports the preparation of activated carbon derived from melinjo (Gnetum gnemon L.) shell waste (MSAC) through carbonization at 300 °C for 1 h, followed by chemical activation using NaOH solutions (1–4 M) for 24 h. NaOH activation of G. gnemon shell carbon is introduced for the first time to enhance its surface characteristics and adsorption performance. Structural and surface modifications before and after activation were characterized by FTIR and SEM-EDX analyses. Batch adsorption experiments were performed to evaluate the effects of contact time, initial pH of MB, and dye concentration on MB removal. NaOH activation significantly improved the surface functionality and porosity of MSAC, resulting in a maximum adsorption capacity ( ) of 148.214 mg/g at pH 7.0 and an initial concentration of 200 ppm within 35 min. The adsorption process followed the Langmuir isotherm (R² = 0.963) and pseudo-second-order kinetics, indicating monolayer chemisorption on a homogeneous surface. These findings demonstrate that NaOH activation effectively enhances the adsorption performance of G. gnemon shell waste–based carbon, making it a low-cost, sustainable adsorbent for the treatment of dye-laden wastewater.

Novel Microfluidic Design and Lab-on-a-Disc Adaptation for Efficient Hematocrit Screening at the Population Level

Santi Rattanavarin — 2026-04-08

Hematocrit (Hct) measurement is a crucial diagnostic parameter for evaluating oxygen transport capacity and detecting anemia or polycythemia. Conventional microhematocrit methods, while widely used, have limitations, including the requirement for relatively large blood volumes, fragile glass capillary tubes, manual sample handling, and reliance on high-speed centrifugation, restricting their practicality in point-of-care testing (POCT). Lab-on-a-disc (LoD) centrifugal microfluidic platforms have emerged as promising POCT solutions, offering automation and efficiency in blood analysis. However, most existing designs incorporate multiple microfluidic channels and sample inlets on a single disc, making them impractical for single-use applications. This study presents a novel, single-use microfluidic-based blood collection device integrated with a LoD system for efficient and minimally invasive hematocrit screening. The device requires only 5 µL of blood and utilizes capillary action for self-filling, eliminating the need for wax sealing. The optimized microfluidic design enables low-speed centrifugation (7,000 rpm for 5 min) while maintaining high accuracy (R² = 0.9996) compared to the standard method. An automated image-processing system ensures precise hematocrit measurement, while QR integration enhances sample identification and data management, making this system ideal for large-scale screening. The compact and lightweight design makes it highly suitable for mobile healthcare screening units, enabling rapid, safe, and cost-effective hematocrit assessment in remote and resource-limited settings. This proposed method significantly advances accessibility and efficiency in population health monitoring.

Numerical Simulation & Push-off Test Validation of Full-Depth Precast Bridge Decks with Large Stud Clusters in UHPC Shear Pockets

Kerati Suwanpakpraek — 2026-01-12

Full-Depth Precast Concrete (FDPC) bridge deck panels are increasingly used in highway construction due to their rapid installation, ease of replacement, and cost-effectiveness. To improve composite action, clusters of large headed-stud connectors embedded in Ultra-High-Performance Concrete (UHPC) shear pockets have been introduced, however, this configuration often induces high stress concentrations and premature cracking around the pockets. This study develops and validates a finite element (FE) model of FDPC panels incorporating L-angle confined UHPC pockets with clustered large studs, based on push-off tests under eccentric loading. The FE simulations accurately reproduced experimental behavior, with predicted ultimate loads and crack patterns closely matching test results for specimens with a cluster of 4, 6, and 8 studs. Parametric analyses showed that finer mesh sizes (10–30 mm) improved crack localization but underestimated ultimate loads (up to 8.3%). Push-off stiffness was influenced by LVDT placement (with 10–20%) due to localized slip and by eccentric loading positions, which significantly affected shear capacity and premature crack pattern. L-angle confinement enhanced shear resistance by up to 15%. Comparisons with experimental data and American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) bridge design equations confirmed that the FE model provides a reliable and efficient analytical tool for optimizing FDPC bridge deck connections with large stud clusters and UHPC shear pockets.

Optimization and High-Efficiency Photocatalytic Degradation of Petroleum Refinery Wastewater using SiO₂/TiO₂ Nanocomposite under UV Irradiation

Sarmad Abdulrazzaq Rashid — 2026-04-28

The critical issue of environmental contamination caused by petroleum refinery wastewater (PRW) has attracted significant attention from researchers due to its harmful effects on human health and ecosystems. The real PRW was successfully treated using Silica-Titania (SiO₂/TiO₂, with a weight ratio of 2.5/97.5%) as a novel photocatalyst to remove organic compounds from real wastewater in a newly designed photocatalytic radiation chamber. SiO₂/TiO₂ was prepared by the sol-gel technique and assessed by the XRD, FTIR, FESEM, EDAX, AFM, and BET analysis. Response surface methodology was used to optimize solution pH, catalyst dosage, and reaction time. The results showed that SiO₂/TiO₂ dosage had the most significant impact on the COD reduction efficiency at optimal conditions of pH 3, SiO₂/TiO₂ dosage 2.29 g/L, and time 5.46 h, achieving 94% COD removal and a correlation coefficient of 98.54%, with an energy consumption of 1.719 kWh/L. SiO₂/TiO₂ maintained excellent stability after undergoing five cycles, achieving more than 87.8 % reduction of COD. The outcomes highlighted the synergistic effect between the SiO₂/TiO₂ photocatalyst and the new chamber design, showing significant enhancements in PRW treatment. Despite these promising results, the study was limited to a single PRW sample and a specific UV intensity. The designed photocatalyst can be examined for various wastewater compositions, scale-up feasibility, and long-term operational stability. Finally, the process revealed efficient performance and showed potential to be a cost-effective and eco-friendly approach for COD reduction from PRW.

Performance Enhancement of Ternary Blending of Biodiesel, Yang-Na (Dipterocarpus alatus) Oil, and Plastic Waste Pyrolysis Oil for Agricultural Diesel Engines

Wuttichai Roschat — 2026-03-23

The growing dependence on fossil fuels and the increasing burden of plastic waste underscore the urgency of developing sustainable energy solutions. This study investigates ternary liquid biofuel blends composed of biodiesel derived from waste cooking oil, distilled Yang-Na (Dipterocarpus alatus) oil, and plastic waste pyrolysis oil for use in agricultural diesel engines. The fuels were analyzed using Fourier Transform Infrared Spectroscopy (FT-IR), Gas Chromatography (GC), Gas Chromatography–Mass Spectrometry (GC-MS), and physicochemical tests according to ASTM D6751 and EN 14214 standards. Various binary and ternary ratios were prepared and compared with commercial B10 diesel. Engine performance and emissions were evaluated using a single-cylinder Kubota RT100 diesel engine at different speeds, along with field tests on walking tractors in Sakon Nakhon Province, Thailand. Biodiesel contributed oxygenated esters that improved combustion but exhibited high viscosity. Distilled Yang-Na oil showed suitable viscosity and energy content but exceeded density limits, whereas pyrolysis oil provided high calorific value but suffered from poor stability and acidity issues. Optimal blends at 60:20:20 and 70:15:15 (Biodiesel:Yang-Na:Pyrolysis) achieved balanced properties, met international standards, and provided heating values close to commercial diesel. Engine tests demonstrated enhanced torque, reduced fuel consumption, and lower CO and HC emissions. These results demonstrate that ternary blending of local and waste-derived oils can yield efficient, eco-friendly biofuels that support rural energy security and sustainable agriculture.

PGME Alkaline Wastewater Distillate Treatment by an Alkaliphilic Microbial Consortium: Optimization using Response Surface Methodology with Central Composite Design (RSM-CCD)

Lance Angelo Tamondong Rovillos — 2026-06-04

Glycol ethers, especially propylene glycol methyl ether, are widely used as organic solvents in many fields. Although physicochemical treatments are relatively common in treating industrial effluents, their production produces wastewater with extreme conditions like high alkalinity and high chemical oxygen demand (COD), warranting the need for alternatives. In this study, response surface methodology (RSM) was adapted to optimize the operating conditions for the treatment of propylene glycol methyl ether-alkaline wastewater distillate (PGME-AWD) using an alkaliphilic microbial consortium. Thirteen reactors were run according to a central composite design (CCD), creating surface models for peak percentage COD removal, COD removal rate constant, and percentage true color (TC) change by changing values for the factors: initial reactor pH (IRP) from 7.0 to 11.0 and initial substrate concentration (ISC) from 1.0 %v/v to 3.0 %v/v. Pseudo-first order kinetics, with the highest average regression coefficient (RSQ) value from curve-fitting, was used to calculate rate constant parameters. Numerical integration was used to obtain TC parameters. Based on the models obtained, optimal conditions for the responses include the following: IRP of 8.569 and ISC of 1.038 %v/v for the first; IRP of 8.566 and ISC of 1.00 %v/v for the second; and 11.000 and ISC of 3.000 %v/v for the third. This shows that optimizing the third response contradicts the optimization of the first two responses, suggesting separation of treatment into stages: one for COD removal and one for color and turbidity.

Production and Economic Evaluation of Biobased Detergent from Waste Cooking Oil

Jabosar Ronggur PanjaitanHamonangan Panjaitan — 2026-04-02

Waste cooking oil is an abundant food waste resource. Converting waste cooking oil into high-value products, such as methyl ester sulfonate (MES) surfactants, is one approach to improving its economic value. MES can be used as a bio-based detergent due to its biodegradability compared to synthetic surfactants. This study investigated the production of a biobased detergent derived from MES surfactant using waste cooking oil as the raw material. MES was produced through two stages: transesterification of waste cooking oil to produce methyl esters, followed by sulfonation of the methyl esters to produce MES. Additional supporting materials were then incorporated into the MES to formulate the biobased detergent. The results showed that the MES-based detergent had a pH range of 10–12. A formulation consisting of 20 g of MES and 15 g of sodium silicate was identified as the optimal composition, as it provided good oil emulsification and foam stability. An economic analysis indicated that producing biobased detergent within a biorefinery framework—where waste cooking oil is processed into both biodiesel and MES as co-products—is more profitable than producing biobased detergent alone. The standalone production of bio-based detergent was not economically viable, yielding a negative net present value (NPV) of 65,060,382 USD. In contrast, the biorefinery approach, with a processing capacity of 4,000 kg of waste cooking oil per hour, achieved a return on investment (ROI) of 58.72%, a payback period (PBP) of 1.24 years, a net present value (NPV) of 37,386,064 USD, and an internal rate of return (IRR) of 59.67%.

Pulsed Electric Field Processing to Reduce Oxalate Content in Walur Tuber: Effects of Electric Field Strength, Soaking Time, and Sequential Treatments

Rani Anggraeni — 2026-03-17

Walur tubers contain high levels of oxalates, which raise nutritional concerns and necessitate their reduction. Pulsed Electric Field (PEF) treatment is a non-thermal technology that applies high-voltage pulses to enhance mass transfer in plant tissues, thereby facilitating the release of oxalates from intracellular matrices. This study aimed to determine the optimal PEF conditions for reducing oxalate levels by evaluating the effect of electric field intensity, soaking time, and sequential treatments. Tuber samples were subjected to various PEF treatments, after which total oxalate content was quantified using HPLC, while structural changes were examined using SEM and TEM. The results showed that an electric field of 3.32 kV/cm effectively reduced oxalate content, while a 5-minute soaking significantly enhanced oxalate diffusion. Two consecutive PEF treatments also resulted in a reduction of oxalate levels, although this decrease was not as significant as that achieved through the combination of PEF and soaking. SEM analysis revealed fractures in calcium oxalate crystals and the formation of debris, while TEM analysis showed the cellular damage after PEF treatment at 1.08 kV/cm, indicating irreversible electroporation. The optimal conditions for oxalate reduction in walur tubers were achieved through a PEF treatment at 1.08 kV/cm combined with a 5-minute soaking. This condition yielded the lowest oxalate levels, recognized as the most energy-efficient option, resulting in statistically similar reduction of oxalate (p-value > 0.05) to that achieved with higher field strengths. These findings suggest that PEF is a promising and sustainable method to enhance the quality and safety of walur tubers.

Rheological and Molecular Modifications of Recycled PET Induced by Chain Extenders for Enhanced 3D Printing Processability

Nismar Parneam — 2026-03-23

This research investigated the processability of recycled poly(ethylene terephthalate) (rPET) derived from PET bottle waste to form filaments for 3D printing by modifying its molecular structure from linear to branched chains using different types and amounts of epoxide chain extenders. The rheological properties, processability, and morphology of the modified rPET were examined using a rotational rheometer, a twin-screw extruder, and a camera image technique, respectively. The highest filament performance was achieved with the addition of 12.5 parts per hundred (pph) of ethylene/n-butyl acrylate/glycidyl methacrylate copolymer, resulting in improved processability and increased shear viscosity. This material exhibited pseudoplastic flow at low shear rates. Additionally, the incorporation of 0.3 pph of styrene-methacrylate-glycidyl methacrylate copolymer further enhanced shear viscosity at low shear rates, resulting in a filament with a smoother surface. Thermal stability and the completion of interactions between rPET and chain extenders were confirmed using a rheometer in oscillatory time-sweep mode. These findings suggest that optimal modification significantly enhances the suitability of rPET for manufacturing 3D printing filaments in the industrial sector.

Synergistic Removal of 4-Chloroaniline from Contaminated Water via Biochar-enhanced Microbial Degradation and Adsorption Using Carbonized Wood Waste

Taksaporn Boonta — 2026-02-17

4-chloroaniline (4-CA) is a widely used aromatic amine, resulting in contamination in aquatic environments. Due to its high toxicity and persistence, 4-CA has been designated as a priority pollutant. This study aims to investigate 4-CA removal using an integrated system of biochar (carbonized wood waste) and Bacillus subtilis GRSW2-B1 (GRSW2-B1). The study consists of three parts: 1) evaluation of 4-CA removal by biochar, GRSW2-B1, and biochar and GRSW2-B1 combination, 2) investigation of 4-CA degradation kinetics, and 3) examination of the role of biochar in 4-CA removal. The result showed that biochar provided good 4-CA adsorption, following the Langmuir model, with a maximum capacity of 4.9 mg/g. The combined system of biochar and microbial cells (designated as BC-G1) achieved a removal efficiency of up to 73%, while microorganism alone (G1) yielded a value of 45%. For the 4-CA degradation kinetics, both G1 and BC-G1 systems followed the Andrews model, with an inhibition concentration of 65 mg/L. Field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and fluorescence excitation-emission matrix (EEM) spectroscopy revealed that biochar enhanced 4-CA removal via: 1) adsorption on the biochar surface and stimulation of extracellular polymeric substance (EPS) production, and 2) enhancing biodegradation by facilitating redox-related electron transfer. The EPS-related functional groups, aromatic proteins, and fulvic and humic acid-like compounds showed increased levels in BC-G1, which is associated with electron shuttling and mediation processes. Overall, the integration of biochar and microbial cells significantly improved 4-CA removal, highlighting a promising, sustainable approach for the remediation of emerging toxic contaminants.

The Effect of CaCl2 Cross-Binding Agent Concentration on Alginate-Carboxymethyl Cellulose-Oil Palm Empty Fruit Bunches Gel Granules as a Methylene Blue Adsorbent

Firda Dimawarnita — 2026-06-09

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.

X-Band Metamaterial-Based Resonant Sensor for Food Quality Monitoring

Fahmiruddin Esa — 2026-06-30

This paper presents a highly sensitive metamaterial-based resonant sensor operating at X-band for rapid and non-destructive monitoring of food quality. The sensor incorporates an I-beam and C-shaped resonator configuration, with quality assessment achieved through resonant frequency shift and resonance broadening, reflected in the quality factor (Q-factor). The structure was designed and optimized using Computer Simulation Technology (CST) Microwave Studio Suite and experimentally validated using a network analyzer with an X-band rectangular waveguide. The unloaded X-band waveguide-integrated resonator exhibited a high Q-factor of 36.463, suitable for powder characterization. For semi-liquid and liquid samples, a custom 3D-printed cuvette was introduced to improve handling and measurement stability, increasing the Q-factor to 43.498 due to higher moisture sensitivity. The sensor’s applicability was demonstrated on cooking powder, oil, and honey. It successfully differentiated soup powder and curry powder with a minimal moisture difference of 0.3%, where increasing moisture content reduced the Q-factor due to enhanced microwave absorption. For honey samples, the Q-factor showed strong correlation with sugar concentration, decreasing with higher glucose and fructose content as reduced free water and increased density altered dielectric properties. Viscosity trends reflect not only sugar concentration but also the influence of bioactive compounds such as polyphenols and flavonoids. In cooking oil analysis, the sensor clearly distinguished fresh and used oil through slight resonant frequency shifts and Q-factor variations, even when FTIR spectroscopy showed limited quantifiable color-related changes caused by oxidation and triglyceride polymerization. Rheological measurements indicated higher viscosity in fresh oil (2.2–2.7 mPa·s) compared to used oil (1.3–1.5 mPa·s), consistent with thermal degradation effects. Overall, the proposed metamaterial sensor demonstrates enhanced sensitivity, compactness, and versatility, confirming its strong potential for real-time industrial food quality monitoring.