Journal of Science and Technology - IUH

OPTIMIZING PROTOCOL CONDITIONS FOR ANALYZING ACRYLAMIDE IN COFFEE BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY-TANDEM TRIPLE QUADRUPOLE MASS SPECTROMETRY (HPLC-MS/MS)

Lê Đình Vũ — 2025-08-29

This study investigated and optimized the protocol for analyzing acrylamide toxicity in roasted coffee by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The conditions of the equipment, mass spectrum, stationary phase, mobile phase, and sample processing procedure were investigated, and the optimal choice for the analysis of acrylamide in coffee samples was selected. The ZORBAX Eclipse C18 chromatographic column and the mobile phase HCOOH/MeCN 0.1% FA were selected with the optimized solvent program for the analysis process. Furthermore, the optimal conditions of the sample preparation protocol were evaluated such as the extraction solvent was EtOAc, the extraction temperature was 80°C, the sample cleanup column was SPE C18, and the standard solvent was MeCN/HCOOH 0.1% (1/1, v/v). The analytical protocol was then applied to analyze 42 roasted coffee samples in Ho Chi Minh City. The results showed that 71.4% of the samples were positive for acrylamide, of which 14.3% exceeded the maximum permission level according to European regulations (400 µg/kg).

SYNTHESIS AND ANTIOXIDANT EVALUATION OF DIBENZAL-ACETONE AND NOVEL AMINE DERIVATIVES FROM BENZALDEHYDE

Nguyen Van Son — 2025-08-29

Dibenzal-acetone (DBA) is a significant chalcone compound synthesized via the aldol condensation reaction between benzaldehyde and acetone in an alkaline medium. Numerous studies have demonstrated that DBA and its derivatives have broad applications in pharmaceutical chemistry, materials science, and optical technology. In this study, we successfully synthesized eight novel amine derivatives of DBA using the Mannich reaction. The structures of these compounds were elucidated through physicochemical analysis methods, including FT-IR and NMR spectroscopy. Additionally, their antioxidant activities were assessed using the standard ABTS method. The results indicated that all compounds exhibited antioxidant potential, with compounds 2, 3, and 5 demonstrating remarkable activity, showing IC50 values of 5.82, 6.35, and 8.23 µM, respectively. Notably, these values were lower than that of the reference compound Trolox (IC50 = 8.69 µM), suggesting that these derivatives could serve as promising candidates for future antioxidant drug development.

STUDY ON APPLICATION OF MATERIAL FROM ELONGATE COCKLE SHELLS IN HEAVY METALS TREATMENT IN SINGLE AND MULTI-COMPONENT SOLUTIONS

Đỗ Thị Long — 2025-08-29

In this study, by grinding and soaking in phosphoric acid solution, a powdered material from elongate cockle (Cardioidea family) was prepared, capable of treating heavy metals in single and multi-component solutions. By XRD, FTIR, SEM, and EDX analysis methods, the structural characteristics of the materials before and after activation were identified. In addition to the main component of CaCO₃ in the form of aragonite and calcite, activated material also contained Ca(H₂PO₄)₂, which partially changed the properties and durability of the material in an acidic environment. Under the conditions of 0.1 g of material, pH 4, and 30 min, Pb(II) and Fe(III) ions were well removed from individual solutions (over 97% with concentrations not exceeding 500 mg/L for Pb(II) and over 88% for solutions with concentrations not exceeding 400 mg/L for Fe(III)), but Cr(VI) was not adsorbed. The Freundlich isotherm model was suitable for describing Pb(II) and Fe(III) adsorption. Furthermore, the study also revealed different types of interactions that occurred when metals were adsorbed from multi-component solutions. While the interaction between Pb(II) and Fe(III) was competitive, the interaction between Fe(III) and Cr(VI) was supportive, which helped the material to adsorb and treat most of Cr(VI) from the Fe-Cr binary and even the Fe-Pb-Cr ternary solutions, although Cr(VI) was not adsorbed from the single solution. The adsorption mechanism was also proposed to explain the experimental results. The study has demonstrated the feasibility and effectiveness of the phosphoric acid activated material, from elongate cockle shells, in treating individual metals or their mixtures in the aqueous environment.

FACILE SYNTHESIS OF POLYMER MEMBRANES AND THEIR APPLICATION FOR SALT WATER AND DYE PURIFICATION

Nguyễn Hữu Trung — 2025-09-05

Ensuring the quality of water resources (especially freshwater) to meet requirements for activities in human life, manufacturing, and environmental aquatic protection is one of the major challenges to countries around the world, mostly developing regions and significantly affected homelands by climate change like Vietnam. Therefore, cleaner production, recycled waste materials, and water purification technologies are essential solutions to apply in industry, production, and life. Water purification technologies by membrane such as permeation membranes, nanofiltration membranes, cation and anion membranes, distillation membranes, diffusion membranes, etc. are being applied more and more widely. In this work, the obtained polymer membranes are synthesized using environmentally friendly and biodegradability materials such as modified starch (PS), polyvinyl alcohol (PVA), and poly acrylic acid (PAA), followed by application for treatment of salted and dyed water. The result shows that as-made polymer membranes have good mechanical properties and durability. Additionally, the treatment efficiency of the diffusion membrane at atmospheric pressure with the NaCl-salted water reaches 84% and contaminated-methylene blue (MB) water reaches 71%. The obtained polymer membranes hold many advantages and potential for use in industrial-scale water purification and treatment technology.

ANALYSIS OF THE INFLUENCE OF MATERIALS ON THE DURABILITY CHARACTERISTICS OF BRAKE DISCS ON VEHICLE

Nguyễn Xuân Ngọc — 2025-09-05

Currently, most passenger cars often use disc brakes because this mechanism brings safety and fast operation. During the movement of the vehicle, the brake disc operates continuously, so it is easy to change the durability compared to the original, so manufacturers need to choose the appropriate material to make the brake disc at a reasonable price. The finite element method is applied based on Ansys to analyze the stress and deformation of hydraulic brake discs for passenger cars corresponding to materials. The 3D analytical model of the disc is built using SolidWorks software. The simulation shows that the structural steel with stress and strain of 48.778 MPa and 0.078082 mm respectively is suitable for making brake discs. This result serves the research work to improve brake discs or for manufacturers of automobile brake systems.

RESEARCH ON THE DRYING KINETICS OF ANGELICA SINENSIS

Lê Thị Bích Nguyệt — 2025-09-05

The effect of drying temperature on the drying kinetics of Angelica sinensis was experimentally studied using the hot air drying method. The experimental data show that drying curves were fit to Wang and Singh model and the Logarithmic model to predict the drying kinetics of Angelica sinensis. The effective moisture diffusivity values are 4.56×10⁻¹¹, 6.85×10⁻¹¹, and 9.13×10⁻¹¹ m²/s for drying temperatures of 40, 50, and 60°C, respectively. The activation energy value of Angelica sinensis slices was also determined to be 30.1 kJ/mol based on the Arrhenius equation.

SUSTAINABILITY IN TEXTILES AND FASHION: ETHICAL CONSIDERATIONS REGARDING ANIMAL-DERIVED MATERIALS

Uyên Tú Trần Nguyễn — 2025-08-29

Sustainability in the textile and fashion industries has emerged as a critical topic in recent decades as these sectors confront significant environmental and ethical challenges. Notably, the use of animal-derived products such as wool, silk, down, leather, and fur has become central to global discussions on sustainable fashion, continuing to incite ethical debates. This paper focuses on analyzing the ethical dimensions concerning animal welfare within the fashion industry, including regulations on livestock farming and the involvement of animal rights organizations. These issues not only influence the evolution of the fashion sector but also significantly impact consumer perceptions regarding humanitarianism and sustainability in fashion consumption. Furthermore, in Vietnam, the concept of animal ethics in fashion has yet to be extensively discussed, indicating a need for further research and dialogue to enhance community awareness of this issue and to promote the development of sustainable fashion in VietNam within the context of globalization.

RESEARCH, COMPILATION, TEACHING THE KHUC DYNASTY IN PRESENT VIETNAMESE HISTORY

Thắng Hữu Trần — 2025-08-29

Abstract. The article summarizes some notes, views, and assessments of experts and historical compilers in our country about the Khuc dynasty in histories from the Middle Ages to the present, and points out a Some assessments and assessments are not consistent between past and present histories regarding the historical milestone of the end of the Northern domination period - the beginning of a long period of autonomy for the nation in particular and the Khuc dynasty in general. From there, we boldly propose to researchers, compilers, and teachers of national history some ideas to soon reach consensus on a number of issues that have received/are receiving attention from the academic community. Compiled and taught about the Khuc dynasty in recent times.

Key word. Khuc dynasty, Khuc Thua Du, Khuc Hao, Khuc Thua My dynasties

STUDY ON THE POSSIBILITY OF ACTIVATION OF POLY(ETHYLENE TEREPHTHALATE) FABRIC BY PLASMA DBD AT INDUSTRIAL SCALE

Khanh Vũ Thị Hông — 2025-08-29

The paper presents the results of study on the possibility of applying DBD plasma to activate Poly(ethylene terephthalate) (PET) fabrics on an industrial scale. Research using DBD plasma generator with dimensions 1300 x 1950 x 1860 mm, Plasma zone has dimensions of length x width of 800 x 1800mm. For PET fabric weighing 170 g/m², the study selected the following plasma parameters: discharge gap was 3 mm; fabric movement speed was 1,8 m/min; plasma current intensity was 3,5 A. The wicking capacity of fabric in the warp and weft directions of the fabric was used to evaluate the degree of fabric activation. The results showed that after DBD plasma treatment, the wicking capacity of the fabric increased significantly compared to the untreated fabric (37% in warp direction and 24% in weft direction). These results indicate that atmospheric DBD plasma can be applied to activate PET fabrics on an industrial scale.

APPLICATION-ORIENTED TEACHING OF GENERAL SUBJECTS (MATH - PHYSICS) FOR TECHNICAL MAJORS

Vương Lê — 2025-08-29

Application-oriented training is becoming a trend of many universities today in Vietnam. Therefore, research and analysis to make improvements and innovations in training programs to ensure both scientific quality and adherence to specialized practice is an urgent requirement for training institutions. so that training brings practical results. From the reality of application-oriented training at Ho Chi Minh City University of Industry, this article presents an approach for teaching basic subjects (Math, Physics) and subjects of mechanical engineering (technical vibration). From there, we give some recommendations and propose some solutions to improve the quality and efficiency in the training process.

STUDY OF HIGH-ORDER ANTIBUNCHING OF TOTAL FREQUENCY PHOTONS IN A POLYATOMIC AND PHOTON INTERACTION SYSTEM

Đặng Hữu Định — 2025-09-05

This paper studies the antibunching properties of the total frequency photons generated by the atomic interaction system with N photons in the coherent state, the even-odd nonlinear coherent state and the squeezing state. On the basis of the criteria for the existence of high-order antibunching, we give an analytic expression for the general high-order antibunching of the system of N photons of total frequency at the input. The research results show that when the input modes are all in a coherent state, there is absolutely no antibunching property. In the case of input modes in the single-mode coherent state, there will be no antibunching property, but as long as at least one photon in the additional nonclassical state is present, the antibunching property becomes evident when we choose value of amplitude, phase angle and suitable the degree of squeezing. Investigation of antibunching properties according the nonlinear even coherent state or the nonlinear odd coherent state has similar results.

HUMAN ALIENATION IN THE AGE OF ARTIFICIAL INTELLIGENCE: PHILOSOPHICAL DIAGNOSIS, EXPLANATORY FRAMEWORKS, AND POLICY ORIENTATIONS FOR VIETNAM

Đặng Hoàng Vũ — 2025-09-05

This article examines the phenomenon of human alienation in the era of artificial intelligence through the theoretical lens of Marxist-Leninist philosophy and Ho Chi Minh’s thought, considering it as a process in which individuals lose their capacity for critical thinking, control, and subjectivity in labor, education, and social life. By analyzing specific manifestations in Vietnam and offering dialectical explanations, the article argues that artificial intelligence is both a tool for development and a potential source of alienation if not governed by ethical and legal frameworks. Consequently, the author proposes a system of constructive legislative solutions aimed at safeguarding human dignity, preserving foundational social values in the digital transformation process, and ensuring a sustainable and humane path of development for Vietnam in the new era.

REAL-TIME SIMULATION FOR ROBUST CONTROL APPLIED TO ASYNCHRONOUS 3-PHASE INDUCTION MOTOR BASED ON THE PPI CONTROL

Nguyen Vinh Quan — 2025-09-05

This study proposes the method of real-time simulation for the field-oriented control (FOC) of an asynchronous - phase induction motor (IM) based on the parallel proportional-integral (PPI) technique, to control the motor speed. The proposed control strategy requires two independent direct controllers for flux and current through the 3 level-cascade inverters with the algorithm of carrier phase modulation (PM). In particular, the stator field-oriented vector control (SFOC) will be chosen rather than the rotor field-oriented vector control (RFOC) caused by the requirement of voltage, current and stator resistance parameters. The result of real-time simulation is provided by applying Sim-Power-Systems of Matlab-Simulink software via RT-LAB compiler and the hardware simulation in hardware in loop (HIL) via OPAL-RT for 1-Hp, 1400 rad/s IM motor. These simulation and experimental results show the robustness of the PPI controller in the presence of parameter variation, such as, the Rs and Rr resistances increasing by 2 times, changing of torque and speed with the appearance of disturbances.

THE IMPACT OF ECONOMIC POLICY UNCERTAINY ON THE CAPITAL STRUCTURE OF ENTERPRISES IN VIET NAM

Võ Văn Hợp — 2025-09-05

The study aims to examine the impact of economic policy uncertainty on the capital structure of listed firms in Vietnam. It utilizes data from 318 Vietnamese listed companies over the period 2015–2023. The research employs OLS, FEM, REM, and GLS regression methods for analysis and discussion. The results from this dataset indicate that economic policy uncertainty has an inverse effect on firms' capital structures. Specifically, when the level of economic policy uncertainty increases, firms tend to reduce their debt and equity ratios to minimize risk. In addition, capital structure is also influenced by factors such as firm size, profitability, business risk, and economic growth rate. Based on these findings, the study proposes several policy implications to support firms in optimizing their financial strategies amid an unstable economic environment.

EFFECTS OF LIVE STREAMERS’ PERFORMANCE SKILLS ON OPTIMIZING DIRECT SALES ON TIK TOK PLATFORM

Nguyễn Nguyên Phương — 2025-09-05

The live streamers on the TikTok platform play a vital role as the “soul” of the live stream through their lively skills, thereby creating interaction, enhancing viewer engagement, and influencing purchase decisions. The study aims to assess the impact of factors related to performance skills including interactivity, persuasiveness, creativity, distinctiveness, and attractiveness in presenting promotions on the intention and purchase decisions of viewers during live streaming sessions. By applying models and theories such as ELM, TPB, SOR, synthesizing relevant studies, and analysing quantitative data collected from 394 experienced users who watch livestreams and make purchases on TikTok, combined with the PLS-SEM method to measure the effects of these factors on purchase intent and purchase decisions. The analysis results indicate that all the proposed factors in the model significantly impact the purchase intention of viewers towards live streams on the TikTok platform. Based on the research findings, the authors provide managerial implications to enhance business effectiveness for individuals, small businesses, and enterprises using live streaming on the TikTok platform to sell products.

AUDITOR’S STRESS AFFECTING AUDIT QUALITY: AN INVESTIGATION IN VIETNAMESE AUDITING FIRMS

Trần Khánh Lâm — 2025-08-29

The purpose of this study is to investigate factors that influence auditor stress and the impact of auditor stress on reduced quality reducing behaviour job performance. We surveyed 906 auditors who are working in auditing firms in Vietnam. The research design relies on exploratory factor analysis and regression analysis to ensure the reliability and validity of the results. The findings show that auditor stress is positively related to professional pressure (e.g., workload and time pressure) and leadership style but is negatively related to role ambiguity and conflict. However, we do not find evidence that type-A behaviour is related to auditor stress. Next, we find that auditor stress is related to reduced audit-quality behaviour.

The research is beneficial for practitioners, especially directors of auditing firms. Understanding auditor stress and its impacts on reduced quality reducing behaviourreduced quality reducing behaviourjob performance can help auditing firms establish a working environment and policies to support auditors. This is the first to document evidence for auditor stress and its impacts on reduced quality reducing behaviour in the Vietnamese market.

This study addresses the critical need for understanding auditor stress and its impacts on audit quality in Vietnam, a rapidly developing market where auditing practices face unique pressures and challenges. Our empirical results reveal that auditor stress significantly influences behaviors relating to reduced audit quality (REAQ) (β = 0.373, p < 0.01), underscoring the importance of managing auditor stress effectively to maintain audit quality standards.

RESEARCH ON THE EFFECT OF FLY ASH CONTENT AND PLASTICIZER ADDITIVE ON THE STRENGTH CHARACTERISTICS OF CEMENT-FLY ASH MORTAR

Đinh Hải Anh — 2025-09-05

This paper presents the results of an experimental investigation assessing the impact of fly ash content and plasticizer additives on the strength and flowability characteristics of mortar. In this study, fly ash was used to partially replace cement, with replacement contents of 0%, 5%, 10%, and 15%. The fine aggregate was natural sand, and the water-to-binder ratio was specified as 0.3. The mortar was supplemented with plasticizer at a rate of 1.0%, 1.5%, and 2.0%. The samples were cured in room conditions (temperature 27±2°C, humidity 95±5%) until the day of testing. The results indicated that the compressive strength of the 7-day samples was inversely proportional to the amount of fly ash that replaced cement. After 56 days of curing, the samples containing 5%, 10%, and 15% fly ash replacing cement have higher compressive strength than the control sample without fly ash. The ratio of plasticizers also affects the fluidity of the fresh mortar. When the ratio of plasticizers increases, the fluidity of mortar increases.