Engineering and Technology For Sustainable Development

NO Adsorption on Zeolites and Active Carbon toward the Application for the Treatment of Highly Concentrated NOx in Industry

The development of the economy and industry is accompanied by the emission of a large amount of exhaust gases such as NO, NO2, and N2O, which have a negative impact on the environment. In the study, the NO adsorption on zeolites and activated carbon was examined and compared. The adsorbents were also characterized using N2 physical adsorption, NO temperature-programmed desorption, Scanning Electron Microscopy, and Energy-Dispersive Spectroscopy to expose specific surface area, adsorption ability, material morphology, and elemental content of the samples. The results showed that the NO adsorption efficiency on zeolite samples was superior to that of activated carbon due to the larger surface area and higher metal cation content, leading to their higher adsorption capacity due to the chemical adsorption at these metal cation sites. The modification of the adsorbent by adding Fe2+ on Zeolite ZX5 has enhanced the active sites that are beneficial for the NO adsorption process, helping to improve the NO adsorption capacity compared to the original sample.

First-Principles Study on the Electronic Structure and Optical Properties of α-(AlxGa1-x)2O3 Alloys

The study focuses on exploring the exceptional electronic and optical properties of the α-(AlxGa1-x)2O3 alloys (AlGaO) using advanced density functional theory (DFT) with hybrid functional methods. By varying the Al content (x) from 0 to 1, the bandgap expands from 5.288 eV to 8.819 eV while maintaining its direct nature. The incorporation of Al significantly enhances the material’s ability to absorb high-energy ultraviolet light, particularly in the deep ultraviolet region (wavelength < 200 nm), due to the strong covalent nature of Al-O bonds and the widened conduction band. The absorption spectra exhibit a distinct shift toward higher energies as the Al ratio increases, accompanied by pronounced optical anisotropy along the x and z crystallographic directions. These characteristics highlight the alloy’s flexible tunability, making it an ideal candidate for advanced applications such as ultraviolet band-C (UVC) sensors, germicidal light sources, and anti-reflective coatings. This study not only provides a solid theoretical foundation for optimizing α-(AlxGa1-x)2O3 as a versatile wide-bandgap semiconductor but also paves the way for future experimental studies to fully unlock its potential in next-generation electronic and optoelectronic devices.

Development and Validation of an HPLC-DAD Method for the Determination of 5-Fluorouracil in Plasma

Hoi Bui Van, Phuong Thao Nguyen, Dinh Binh Chu

Cancer remains one of the most significant health challenges worldwide, characterized by uncontrolled cell growth. However, it can be cured by using anticancer drugs. 5-fluorouracil is a drug used to treat various types of cancer with the inhibitory mechanism of the enzyme thymidylate synthase, which is crucial for DNA replication in cancer cells, leading to errors in their growth. Although effective, the short half-life of 5-FU and individual metabolic differences among patients limit its therapeutic potential. Therefore, it is necessary to monitor the 5-FU concentration during treatment to ensure the treatment efficiency. However, monitoring this compound in plasma is challenging due to the coexistence of complicated matrices. The study optimized and validated a sensitive method to quantify 5-fluorouracil in mice plasma using liquid-liquid extraction combined with a high-performance liquid chromatography-photodiode array detector (HPLC-PAD). The technique achieved excellent linearity, precision, accuracy, detection limits (LOD = 1.12 μg/L), and quantification (LOQ = 3.74μg/L). The optimal extraction solvent was ethyl acetate in two replicates (2x3ml), PSA/C18 was the most effective cleaning agent with 97.9 ± 0.2% recovery and the mass of PSA/C18 did not affect the extraction recovery. However, high plasma volume reduced the recovery of 5-FU in plasma. Finally, in vivo studies in mice were used to confirm this method. The findings of this research underscored the importance of personalized dosing strategies based on 5-FU concentration in blood.

The Influence of Oxidizer Content and Energy Additive on Thermal Decomposition and Burning Rate of High Energy-Carrying Composite Materials

During the course of this inquiry, an attempt has been made to understand the thermal decomposition characteristics and burning rate of ammonium perchlorate working as an oxidizer and polyvinyl chloride functioning as a fuel binder for high energy-carrying composite materials. The samples were examined for material morphology and elemental composition by scanning electron microscope and dispersive energy X-ray spectrometer methods. In addition, a NETZSCH simultaneous thermal analyzer comprising a differential scanning calorimeter and a thermogravimetric analyzer has also been utilized to ascertain the thermal decomposition method associated with each composition. The thermal decomposition process of the energy-carrying composite materials consisted of three distinct stages, and the mass loss rate during this process ranged from 100 °C to 500 °C, accounting for 99% of the sample mass. The enhanced catalytic activity of Fe2O3 in ECCMs significantly lowers the exothermic decomposition temperature and increases the total heat release. Besides, the burning rate studies have been conducted at ambient and different pressures with and without Fe2O3, providing valuable insights into the combustion behavior of ECCMs under varying conditions.

Simulation Study on Performance and Emissions of a Diesel Engine Using Diesel-Ethanol-Waste Cooking Oil Blends

Huu Tuyen Pham, Huu Truyen Pham, Van Thu Hoang

Using biofuel for diesel engines is a sustainable solution to solve the current scarcity of petroleum energy sources and environmental pollution problems. The paper presents performance and emissions of a Hyundai D4BB diesel engine when using diesel-ethanol-waste cooking oil blends modeled by AVL Boost software. The test blends comprised 5% of waste cooking oil, and 10%, 20%, 30% of ethanol, and fossil diesel in the rest. Estimated viscosities of the blends were in the range of 2-4.5 mm2/s, equivalent to diesel fuel. The results showed that ratio of biofuel in blends could increase up to 30% of ethanol with 5% of waste cooking oil (called D65E30WCO5) that the engine torque decreased less than 10% whereas exhaust gas emissions reduced significantly. At full load, the average reductions in CO, NOx, and soot emissions were 28%, 24%, and 13% with D85E10WCO5; 40%, 33%, and 25% with D75E20WCO5; 46%, 41%, and 35% with D65E30WCO5. At the load characteristic curve at engine speed of 2000 rpm, the corresponding reductions were 8.71%, 5.33%, and 5.28% for D85E10WCO5; 9.81%, 5.12%, and 31.78% for D75E20WCO5; 10.11%, 4.81%, and 48.73% for D65E30WCO5. These may result from differences in the fuel properties between the blends and diesel fuel.

Optimizing the Form Error of Al6061 Spherical Surfaces in Single-Point Diamond Turning Using Particle Swarm Optimization Algorithm

The paper investigates optimizing form accuracy in Al6061 spherical surface (SS) machining through single-point diamond turning (SPDT) with the swarm optimization (PSO) algorithm. The optimization problem is implemented on the basis of building the relationship between profile accuracy or form error (FE) with cutting parameters including spindle speed (n-rev/min), feed rate (f-mm/min), and depth of cut (ap-μm). Based on the data collection from 15 experiments in the Box-Behnken (BB) model with the specialized software Design Expert support, the modeling results show a high agreement between the predicted data and the actual measured values with high reliability (R2 = 0.9428). By using the PSO algorithm, the optimal FE value of 0.95 μm was found, corresponding to the technological parameter set of n equal 1746 rev/min, f equal 5 mm/min, and ap equal 8 μm. This research significantly lays the foundation for controlling, predicting, and optimizing the FE factor of SS, particularly for Al6061 material and generally for other materials. Moreover, these results will further enhance the SPDT machining of more complex surfaces and reduce optical errors.

Investigation of the pH-Sensing Properties of Anthocyanin-Dyed Silk Fabric Prepared Using the Exhaustion Method

The study reports the successful fabrication of eco-friendly pH-sensing silk fabric utilizing silk woven fabric and anthocyanin dye extracted from Huyet du leaves (HD dye) via ultrasound-assisted extraction (UAE) with an aqueous ethanol solution. The dyeing process was conducted using an exhaustion method, maintaining a liquor-to-fabric ratio of 30:1 at temperatures of 60, 80, and 100 °C for durations of 30, 60, and 90 minutes. Comprehensive characterization of the dyed silk fabrics was performed using ultraviolet-visible (UV-vis) spectra, CIE L*a*b* coordinates, color strength (K/S), color difference (ΔE), Fourier Transform Infrared Spectroscopy (FTIR), optical microscope, and pH-sensing capabilities. The results demonstrate effective incorporation of HD dye into silk fabric, with notable enhancements in color strength corresponding to increased dyeing time and temperature. Importantly, the pH-sensing properties of the dyed fabric displayed a “red-green traffic light” behavior in response to pH variations from 7 to 9, highlighting its potential for innovative smart textile applications.

Research on the Properties of Outsole Materials Composed of Waste Leather Fibers, Waste Fabric Fibers and Natural Rubber

Thuy Hang Le , Luc The Nguyen, Thi Ngan Truong

Recycled materials are currently receiving significant attention from society. In particular, a large amount of waste is generated during the production process in the textile and footwear industries. New products have been developed by combining textile and footwear waste with plastic or rubber. In the study, the authors used fiber (fabric waste torn into fibers), leather waste, and natural rubber to successfully manufacture outsole materials by combining these three primary materials with additional additives and chemicals. After production, the properties of the product were tested. This article presents the results of a survey on the tensile strength, tear strength, hardness, water resistance, dimensional stability, abrasion resistance, and compression performance of the shoe outsole materials produced by Vietnamese Standards. Based on this research, we aim to develop shoe outsole materials that are in line with the principles of the circular economy of the textile and footwear industry and establish a domestic secondary raw material source for footwear manufacturing companies in Vietnam.

Designing a Denim Shirt for Persons with Upper Limbs Locomotor Disabilities

Thi Minh Kieu Tran, Khanh Trang Le , Dieu Trang Trieu, Hoang Anh Do

Functional clothing designed for people with disabilities aims to enhance health recovery, improve lifestyle, fulfill personal expectations, enable them to lead dignified and comfortable lives, and facilitate their integration into both family and society. Research methods in this field focus on document synthesis, motion limitation analysis, and design enhancement. When studying to design collar-buttoned down and long-sleeve shirts for men with limited upper extremity mobility, design solutions need to focus on improving the functionality of the garment. This ensures that people with disabilities can independently put on and take off their clothes without requiring external assistance. One solution is the use of magnetic buttons, which enable wearers to easily fasten buttons, which takes less time and does not require dexterity or the hand muscles strength. Besides, the choice of denim material would improve moisture comfort; while, the shirt was constructed with ventilation at the back yoke and armpits, as well as splits along the sleeves to enhance the movement comfort. The functional male shirt presented in this study meets the needs of people with limited upper limb disabilities by improving their quality of life and promoting health rehabilitation.

Integrating Blended Learning in Engineering Education, a Bibliometric Study of Research Trends and Impact

Thu Hoai Le, Hieu Hoc Le, Thi Thanh Hai Pham

Blended learning has become a prominent approach in engineering education, integrating face-to-face and online modalities. Despite its increasing adoption, research on this topic remains underexplored in a systematic manner. The study applies a bibliometric mapping analysis to examine the evolution of blended learning research in engineering education from 2014 to 2024. A total of 180 peer-reviewed journal articles were retrieved in June 2025 from Scopus and ERIC, and analyzed using VOSviewer and Microsoft Excel. The study identifies publication trends, influential authors, journals, institutions, and countries, and visualizes co-authorship and keyword co-occurrence networks. Findings reveal a post-2020 surge in publications, with significant contributions from North America and Europe, particularly Purdue University. Keyword clustering analysis highlights five thematic directions: course design, learning environments, institutional frameworks, student outcomes, and motivation. Despite these advancements, gaps remain in systemic implementation, longitudinal evaluation of graduate competencies, and cross-regional collaboration. This study offers a comprehensive, data-driven synthesis that not only consolidates the existing literature but also provides actionable insights for researchers, educators, and policymakers. By linking bibliometric evidence to established learning theories, the findings inform both academic research and institutional strategies, and set clear priorities for advancing blended learning as a sustainable and impactful component of engineering education worldwide.