https://jst.vn/index.php/etsd/issue/feed 2026-04-15T00:00:00+00:00 JST - Engineering and Technology For Sustainable Development jst@hust.edu.vn Open Journal Systems https://jst.vn/index.php/etsd/article/view/1332 2026-03-18T04:26:30+00:00 Nang Minh Nguyen anh.phamtuan2@hust.edu.vn Lan Anh Dang anh.phamtuan2@hust.edu.vn Thao Vy Tran anh.phamtuan2@hust.edu.vn Tuan Anh Pham anh.phamtuan2@hust.edu.vn

Torularhodin is a carotenoid of considerable interest due to its potent antioxidant activity and potential applications in the food, pharmaceutical, and cosmetic industries. In the study, the influence of culture conditions, including pH, temperature, and medium composition (molasses concentration and urea supplementation) on biomass formation and torularhodin biosynthesis in Rhodotorula mucilaginosa RL 231-1.51 was systematically investigated. Optimal biomass production was achieved at pH 6.5, 30 °C, and 10°Bx molasses, whereas maximum torularhodin accumulation was observed at pH 7.5, 25 °C, 22°Bx molasses, and 18 g/L urea. Implementation of a two-stage fermentation strategy, designed to decouple biomass growth from carotenoid production, resulted in a maximum torularhodin content of 2628.1 µg/g dry cell weight, corresponding to a yield of 91.98 mg/L. These findings demonstrate that the two-stage fermentation approach is an effective strategy to enhance torularhodin production and holds promise for industrial-scale applications.

2026-03-18T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1170 2025-11-20T10:18:10+00:00 Quang Truong Le ntuelam2010@gmail.com Thi Luu Nguyen ntuelam2010@gmail.com Lan Huong Dang ntuelam2010@gmail.com Phuc Huy Pham ntuelam2010@gmail.com Quoc Binh Nguyen ntuelam2010@gmail.com Thi Thu Thuy Nguyen ntuelam2010@gmail.com Thi Bich Hau Vu ntuelam2010@gmail.com Van Loc Tran thuy.tranthithanh1@hust.edu.vn Van Sung Tran thuy.tranthithanh1@hust.edu.vn Myint Myint Khine ntuelam2010@gmail.com Irina Smirnova ntuelam2010@gmail.com Amandio Vincent Vieira ntuelam2010@gmail.com Thi Phuong Thao Tran ntuelam2010@gmail.com

From the leaves, twigs, and fruits of Helicia petelotii collected from the Hoang Lien mountain range in Sapa, Vietnam, six compounds were isolated including β-sitosterol (1), daucosterol (2), 3-O-[β-D-(6'-nonadecanoate)glucopyranosyl]-β-sitosterol (3), β-arbutin (4), breynioside B (5), and glycerol monostearate (6). Among them, compounds 3 and 6 were isolated from the fruits, while compounds 1, 2, 4, and 5 were obtained from the leaves and twigs. Advanced spectroscopic methods such as NMR and HR-ESI-MS were applied to accomplish the structures identification of the above compounds. The anti-denge potential of compounds 1-6 were examined against two dengue virus serotypes, DENV-1 and DENV-2. Among them compounds 3 and 5 demonstrated inhibitory activity against DENV-2, with PNRT₅₀ values of 18.25 µM and 159.43 µM, respectively, while the remaining compounds were inactive against all the virus serotypes. This is the first report of phytochemicals and antiviral properties of Helicia petelotii against Dengue virus.

2025-11-20T00:00:00+00:00 Copyright (c) 2025 https://jst.vn/index.php/etsd/article/view/1275 2026-02-02T08:47:18+00:00 Hoang Ha Bui ha.hophu@hust.edu.vn Thuy Hang Dam ha.hophu@hust.edu.vn Quynh Huong Luu ha.hophu@hust.edu.vn Phu Ha Ho ha.hophu@hust.edu.vn

Antibiotic resistance in husbandry remains a major global challenge due to the extensive use of antimicrobials in animal production. Probiotics with genetically stable profiles are therefore considered promising alternatives to reduce antibiotic reliance and limit resistance dissemination. This study evaluated the susceptibility of three Bacillus strains: P4QN11, BAD7, and S2.5, and Escherichia coli Ec457 to cefotaxime, and investigated the potential transfer of the bla-CTX-M resistance gene. Disk diffusion assays showed that Bacillus P4QN11, BAD7, and S2.5 had large inhibition zones of 26 to 27 millimeters, indicating high susceptibility, while E. coli Ec457 exhibited a small inhibition zone of 13 ± 1 millimeters, confirming resistance. Cefotaxime resistance of E. coli Ec457 was evidenced by the presence of the blaCTX-M gene detected by PCR. Co-cultivation experiments under selective pressure with LiCl and cefotaxime tested whether Bacillus strains could acquire resistance genes. After repeated co-culture, Bacillus P4QN11, BAD7, and S2.5 remained phenotypically susceptible in disk diffusion tests, and PCR showed no blaCTX-M amplification, confirming gene transfer was not detected. These results demonstrated that the Bacillus strains do not acquire cefotaxime resistance genes from E. coli Ec457, even under selective conditions. This supports their genetic stability and safety for use as probiotics in food and animal feed, help to reduce the spread of antibiotic resistance. Further research should explore longer co-culture periods and genomic analysis to confirm these findings under diverse environmental conditions.

2026-02-02T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1336 2026-03-23T07:15:41+00:00 Quynh Vi Nguyen mai.nguyenngoc@hust.edu.vn Minh Thu Truong mai.nguyenngoc@hust.edu.vn Thi Thanh Thao Do mai.nguyenngoc@hust.edu.vn Ngoc Mai Nguyen mai.nguyenngoc@hust.edu.vn

The study focuses on doping low-cost commercial TiO2 (P25) to synthesize composite photocatalysts, Cu/TiO2 and Ce/TiO2, which decompose organic dyes and perfluorooctanoic acid (PFOA) under mostly visible light of a Xenon lamp. By the basic impregnation method, copper and cerium are successfully doped in P25 with different contents, which is confirmed by some structural analysis, such as X-ray analysis, inductively coupled plasma optical emission spectroscopy, and scanning electron microscopy. The optical band gaps of P25, Cu/P25/1, Cu/P25/5, Ce/P25/1, and Ce/P25/5 are respectively 3.10, 2.96, 2.93, 2.84, and 2.92 eV. Under the Xenon lamp illumination (300-700 nm, 95% visible light), the decomposition ability of Ce/P25/1 with organic dye is the best, 96.7% methylene blue decomposition after 30 minutes, and methyl orange is 90.4% after 50 minutes. The study also looks at how different types of dyes affect the ability of the photocatalysts to break down substances by examining how well the photocatalysts can adsorb the dyes. Moreover, about 22.6% of PFOA is degraded by Ce/P25/1 under the Xenon lamp illumination (300-700 nm, 95% visible light). Therefore, this research compares photocatalytic materials synthesized from cheap commercial sources to decompose pollutants in water, contributing to the development of wastewater treatment technology in Vietnam.

2026-03-23T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1338 2026-03-23T13:12:21+00:00 Tuong Huy Nguyen thang.leminh@hust.edu.vn Thanh Hung Nguyen thang.leminh@hust.edu.vn Dinh Hung Tran thang.leminh@hust.edu.vn Minh Thang Le thang.leminh@hust.edu.vn

The dry reforming of methane (DRM) is a promising route for converting greenhouse gases (CH₄ and CO₂) into valuable syngas (H₂ and CO), offering both environmental and economic benefits. Among the DRM catalysts in literature, nickel-based on hydrotalcite-derived material Ni/MgAlOx was chosen due to its catalytic activity and resistance to carbon residue and metal site agglomeration. The study presents an initial investigation into the effect of different synthesis methods on the physicochemical properties and catalytic performance of Ni/MgAlOx catalysts in DRM. The catalysts, with fixed Ni/Mg/Al ratio of 1.0/2.0/1.5, were synthesized using two different methods: a) co-precipitation with hydrothermal crystallization and b) sol-gel, to study how the differences in synthesis route can affect the catalytic properties and performance of each catalyst. Characterization techniques, including X-ray diffraction (XRD), temperature-programmed reduction (TPR), and scanning electron microscopy (SEM) were employed to analyze the catalysts. The results reveal that the synthesis method significantly impacts the Ni dispersion, metal-support interaction, and stability of the catalysts. Catalysts prepared via co-precipitation exhibited superior activity and stability, attributed to their enhanced Ni dispersion and stronger metal-support interaction. This work provides foundational insights into optimizing Ni/MgAlOx catalysts for DRM, highlighting the critical role of synthesis methods in tailoring catalytic performance.

2026-03-23T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1341 2026-03-24T02:03:56+00:00 Viet Hung Ngo duongxuanbien@lqdtu.edu.vn Van Tuan Ngo duongxuanbien@lqdtu.edu.vn Van Duong Dao duongxuanbien@lqdtu.edu.vn Minh Hoang Vu duongxuanbien@lqdtu.edu.vn Van Nhu Le duongxuanbien@lqdtu.edu.vn Xuan Bien Duong duongxuanbien@lqdtu.edu.vn

The paper presents establishing of a predictive model for surface roughness value of Al6061 material aspherical surface in ultra-precision turning using a single point diamond tool (SPDT). The model employs the structure of a back propagation artificial neural network (ANN). Three cutting parameters are considered, including spindle speed, feed rate, and depth of cut. An experimental matrix was established based on data from 30 actual experiments measuring surface roughness values of aspherical surfaces under corresponding machining conditions for the given parameter sets. Through the evaluation of six specific neural network structures (based on the number of layers and neurons in each layer), an optimal neuron ratio between layers was determined to optimize the predictive model. The ANN structure 3-5-15-1 yielded the best prediction results, as demonstrated by evaluation metrics such as: Coefficient of Determination (R2 equal 0.9999), Mean Square Error (MSE equal 2.6e-4), Root Mean Square Error (RMSE equal 0.0163) and Mean Absolute Percent Error (MAPE equal 0.6949%).Validation experiments, involving six training sessions using MATLAB software, confirmed the high feasibility of the predictive model. This was evidenced by the minimal error (1-2%) between the predicted surface roughness values and the experimental measured roughness values. This research is directly applied to predic surface roughness value of Al6061 aspherical surface in SPDT and serves as foundation for similar studies on different material or surface geometries of machined parts.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1163 2026-01-24T09:57:26+00:00 Assoc. Prof. Tien Duong Nguyen duong.nguyentien@hust.edu.vn

PVC-U plastic pipes are used in many fields such as water distribution, wastewater discharge, electric cable protection systems, gas distribution, etc. The butt fusion welding is often used for large diameter plastic pipes. This welding process is used to weld the pipes which are subjected high pressure. The butt fusion welding process produces durable, high-quality welds at low cost. This paper studies the influence of butt fusion welding parameters such as heating temperature, heating time, heat soak pressure and fusion joining pressure on the tensile strength of PVC-U pipe welding joints. The studied results showed that the reasonable tensile strength of welded joints of PVC-U pipe will be reached in a narrow range of butt fusion welding parameters. The research also indicated that some welding parameters of PVC-U pipe such as heating temperature, changeover time, beat-up pressure, heat soak pressure and fusion joining pressure can be fixed. These parameters do not depend on the diameter or wall thickness of the PVC-U pipe. Other welding parameters such as heating time and joining time will depend on the diameter and thickness of the PVC-U pipe. With reasonable welding parameters, the tensile strength of PVC-U pipe welding joint can reach more than 90% of the tensile strength of base material which meets the minimum requirement of standard. The highest tensile strength of PVC-U pipe welding joint in this study can obtain to 97.6% of the tensile strength of base material.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 Engineering and Technology For Sustainable Development https://jst.vn/index.php/etsd/article/view/1342 2026-03-24T06:58:18+00:00 Ngoc Nhi Nguyen nhinn@huce.edu.vn Viet Dung Duong nhinn@huce.edu.vn Dinh Duc Nguyen nhinn@huce.edu.vn

The study investigates the aerodynamic performance of high-speed trains by focusing on the influence of nose shape and length on drag at a speed of 97.2 m/s. Utilizing the Lattice Boltzmann Method (LBM), we systematically compare blunt and tapered nose designs to quantify their impact on drag reduction. Our findings reveal that an improved nose geometry significantly reduces aerodynamic drag, which in turn leads to improved operational efficiency, lower energy consumption, and noise reduction. Furthermore, the results indicate that nose length is a critical factor in mitigating both concentrated end-face pressure and vortex drag. The analysis of benchmark models like the Shinkansen E5 and Thalys PBA confirms that a well-designed train nose is paramount for achieving superior aerodynamic performance. This research provides a robust scientific foundation for the design enhancement of future high-speed train designs, ultimately enhancing their speed and efficiency.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1343 2026-03-24T07:20:44+00:00 Thanh Tung Dao phuc.damhoang@hust.edu.vn Trong Dat Tran phuc.damhoang@hust.edu.vn Quoc Trieu Nguyen phuc.damhoang@hust.edu.vn Hoang Phuc Dam phuc.damhoang@hust.edu.vn Van Nghia Le phuc.damhoang@hust.edu.vn Ngoc Khanh Duong phuc.damhoang@hust.edu.vn

The study presents a comprehensive analysis of the regenerative braking efficiency of an All-wheels-drive electric vehicle under different traffic conditions using specific simulation software. The proposed model evaluates energy recovery performance across non-rush hours, rush hours, and highway driving cycles in Vietnam, highlighting the influence of traffic density on regenerative braking effectiveness. The results indicate that the highest energy recovery occurs in non-rush hours, where frequent braking events enhance regenerative braking activation. A comparative assessment between low and high-regeneration braking modes shows that the efficiency gap varies significantly depending on traffic flow, with the high-regeneration braking mode consistently demonstrating superior performance. In highway conditions, energy recovery is notably lower due to stable cruising speeds and fewer braking instances. The findings of this research contribute to the advancement of energy-efficient electric vehicle technologies by providing a detailed evaluation of regenerative braking potential under Vietnam driving conditions. This study serves as a reference for optimizing vehicle control strategies and promoting sustainable transportation solutions. By understanding the impact of traffic patterns on regenerative braking efficiency, this research aids in enhancing energy recovery strategies, reducing overall energy consumption, and improving vehicle performance in real-world urban environments.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1344 2026-03-24T07:58:55+00:00 Ngoc Minh Truong minh.truongngoc@hust.edu.vn

The integration of wind energy into electrical grid necessitates the incorporation of wind farms with series compensated transmission systems to guarantee power distribution. This article examines the occurrence of sub-synchronous resonance in wind farm utilizing double-fed induction generator. The system under examination is predicated upon a modified version of the IEEE Second Benchmark (SBM) model specifically designed for sub-synchronous resonance investigations. A dynamic model for the system has been proposed to facilitate an analysis of sub-synchronous resonance phenomena. Eigenvalue analysis is conducted in conjunction with simulation at various wind velocities and series compensation. The distinct oscillatory modes, including sub-synchronous resonance, supersynchronous resonance are subjected to comprehensive analysis. Simulation results are executed to substantiate the efficacy of the proposed methodology.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1345 2026-03-24T08:29:42+00:00 Thi Kim Dung Hoang dung.hoangthikim@hust.edu.vn

Wind energy is one of the forms of renewable energy that has been developed strongly in recent times. Wind turbines are used to take advantage of this free and clean energy source. To increase capacity, developers often increase the size of wind turbines. The increased size of the wind turbine leads to an increase in the size of the blades. Along with the increase in size, the deformation of the blade also increases as the blade size increases. The deformation that occurs during wind turbine operation is due to the pressure load distributed across the blades. Controlling the deformation of the turbine blade that occurs during operation will reduce the risk of cracking and breaking of the blade, thereby improving the performance of wind turbines, especially large sized wind turbines. In this paper, first Computational Fluid Dynamics (CFD) problem was solved to find the load distribution on the blade surface of GE1.5XLE turbine blade of horizontal-axis wind turbines (HAWT) with air velocity of 12 m/s. Then, this load distribution was used as an input condition for Fluid-Structure Interaction (FSI) problem to find out the deformation of the blade. The simulation methods using in this paper were estimated with help of ANSYS software. The results deviated by less than 2% from the manufacturer's data.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1346 2026-03-24T15:25:42+00:00 Tu Van Ha luonghoangtuyetvan9126@gmail.com Thi Viet Ha Ngo luonghoangtuyetvan9126@gmail.com Hoang Tuyet Van Luong luonghoangtuyetvan9126@gmail.com

In the context of digital transformation and sustainable development in the fashion industry, OptiTex software has emerged as a key solution for optimizing apparel design and production processes. This study aims to evaluate the practical effectiveness of OptiTex in Vietnam through a survey of 106 fashion professionals and real-world experiments conducted at Hai Ngoc Garment Co., Ltd. Survey results reveal that OptiTex helps reduce design time by 20%–60% and significantly lowers prototyping costs. Experimental findings further confirm a high simulation accuracy of 92% between the 3D virtual fit and the actual product. Furthermore, the automatic marker-making feature helps save approximately 12% of fabric on average. Despite these benefits, several challenges remain, including the high cost of licensing, the software's complex interface, and the need for user training. The study proposes improvements such as enhancing fabric simulation algorithms, simplifying the user interface, offering intensive training programs, and integrating advanced technologies like AI and blockchain. These findings highlight the considerable value of OptiTex in supporting the modernization and efficiency of Vietnam's fashion industry and provide practical insights for its broader implementation across enterprises and educational institutions in the digital era.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1347 2026-03-24T15:41:14+00:00 Thi Le Nguyen trinh.nguyennhat@hust.edu.vn Nhat Trinh Nguyen trinh.nguyennhat@hust.edu.vn Thi Hong Nhung Tran trinh.nguyennhat@hust.edu.vn Thi Bich Tran trinh.nguyennhat@hust.edu.vn Thi Nga Mai trinh.nguyennhat@hust.edu.vn Thi Linh Vi Nguyen trinh.nguyennhat@hust.edu.vn Thi Hoai Thu Le trinh.nguyennhat@hust.edu.vn Hoa Trung Nguyen trinh.nguyennhat@hust.edu.vn

Fabric consumption is a critical factor in industrial garment manufacturing, as fabric cost constitutes a substantial portion of total product cost. In the study, a systematically constructed dataset of jeans markers under multiple conditions was developed, and an Artificial Neural Network (ANN) model was proposed to predict fabric consumption based on fabric width, the number of garment components, and the number of garments per marker. The dataset was normalized and partitioned into two subsets: 70% for model training and 30% for testing. A four-layer feedforward ANN architecture with two hidden layers comprising 10 and 5 neurons, respectively, was employed, utilizing a unipolar sigmoid activation function and trained via the backpropagation algorithm. The evaluation results demonstrated high predictive accuracy, with a Mean Absolute Error (MAE) of 0.01, Root Mean Square Error (RMSE) of 0.02, and a coefficient of determination (R²) of 0.9296 on the test dataset. The close alignment between actual and predicted fabric consumption confirmed the model’s effectiveness. Compared with traditional linear models such as Bayesian Model Averaging (BMA), the ANN model exhibited superior capability in capturing nonlinear relationships among input variables. These results highlight the strong potential of ANN for practical applications in textile and apparel production, offering a fast and reliable approach for fabric planning.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 https://jst.vn/index.php/etsd/article/view/1019 2025-12-12T08:42:35+00:00 Ms. Thi Quynh Mai Tran quynhmai.hust@gmail.com Mr. Tran Gia Bao Phung giabao2882003@gmail.com Ms. Ngoc Hien Luu hienluungoc.k66hust@gmail.com Thanh Giang Bach hoc.lehieu@hust.edu.vn Assoc. Prof. Hieu Hoc Le hoc.lehieu@hust.edu.vn

This study investigates the psychological mechanisms linking Project-Based Learning (PjBL) to students' awareness of the United Nations Sustainable Development Goals (SDGs) at Hanoi University of Science and Technology (HUST). Based on 192 valid responses and employing PLS-SEM and ANOVA analyses, the results reveal that self-efficacy has positive influence on student’s awareness and knowledgeand engagement with the SDGs. In contrast, learning motivation is found to affect only the evaluation dimension. Significant differences across academic disciplines were also identified in the three dimensions of SDG awareness. The study recommends enhancing the integration of SDGs into PjBL, fostering students’ self-efficacy, aligning learning motivation with SDGs-related content, and providing faculty training. Furthermore, future research should explore external moderating factors - such as institutional policies, support from lecturers and enterprises, and the classroom environments - to strengthen the model’s explanatory power.

2026-03-24T00:00:00+00:00 Copyright (c) 2026 Engineering and Technology For Sustainable Development https://jst.vn/index.php/etsd/article/view/1060 2025-12-15T13:06:31+00:00 Ms Thi My Duyen Tran tranmyduyen12062005@gmail.com Ms Thi Thao Nguyen nguyentheorvp@gmail.com Ms Thi Kieu Oanh Nguyen nguyenthikieuoanh16032000@gmail.com Ms Khanh Linh Do Linh.DK2411956@sis.hust.edu.vn Prof. Thi Quynh Lan Hoang Lan.hoangthiquynh@hust.edu.vn

In the context of modern education, media multitasking behavior has become increasingly common and may be associated with lower levels of academic performance. The study aims to explore the relationship between multitasking intention - based on the Theory of Planned Behavior (TPB) - and actual multitasking behavior, measured using the Media Multitasking-Revised (MMT-R) scale at Hanoi University of Science and Technology. A quantitative research design was conducted with 257 students through an online survey administered over a period of one month. Reliability analyses and Pearson correlations were employed to examine the relationships among variables, followed by multiple linear regression to identify predictors of multitasking intention in the classroom. The results show that Attitude (AT) (β = 0.494) is the strongest predictor of intention, followed by Behavioral Beliefs (BB) (β = 0.269). At the same time, intention was strongly correlated with actual multitasking behaviors, including Compulsive Phone Checking (CPC, r = 0.583), Media Distraction (MD, r = 0.532), and the overall MMT-R scale (r = 0.614). These findings confirm the mediating role of intention in bridging cognition and behavior, and also suggest that sustaining long-term multitasking habits, whether active or passive, may linked to lower levels of self-regulation in classroom learning.

2026-03-25T00:00:00+00:00 Copyright (c) 2026 Engineering and Technology For Sustainable Development