Industrial University of Ho Chi Minh City

With the rapid development in additive manufacturing technologies, the demand for metamaterials characterized by adjustable mechanical features for interdisciplinary engineering applications has become increasingly popular, particularly in sophisticated small-scale systems. This paper pays attention to exploring the dynamic instability responses of functionally graded microplates fabricated from nature-inspired triply periodic minimal surface (TPMS) lattice architectures. The size-dependent instability dynamic behavior of three different sheet-based TPMS lattice architectures: Primitive, Gyroid, and I-graph and Wrapped Package-graph, is analyzed using modified couple stress theory. This study examines TPMS cellular architectures within the framework of uniform and two gradient density distributions. In addition, graphene is uniformly distributed within the TPMS structures to improve the dynamic performance. The dynamic instability regions in this investigation are determined using Bolotin’s procedure. The present findings reveal that the dynamic performance of TPMS lattice architectures outperforms that of both open-cell and closed-cell cellular solids. Additionally, the distribution and density of porosity in TPMS architectures significantly influence structural stiffness. A symmetric porosity pattern is found to yield the best dynamic instability performance, while structural rigidity is significantly enhanced by the addition of graphene. Furthermore, increasing the material length scale ratio and graphene weight fraction results in improved size-dependent dynamic instability characteristics. The present findings bring valuable insights into dynamic performance as well as contribute to the development of advanced lattice structures at the small scale, inspired by nature and reinforced with graphene.

A comprehensive investigation of the input parameters in a plasma–liquid interaction (PLI) for the removal of methylene blue (MB) in artificial wastewater was conducted using a cold atmospheric pressure Ar plasma jet (jet temperature ≤ 40 °C). The Ar plasma jet was generated by a gliding arc configuration and driven with a 50 Hz AC high voltage. The effects of key parameters on MB removal efficiency were systematically examined, including stirring solution, distance from the plasma jet source to the liquid surface, interaction time, initial MB concentration, and Ar flow rate. These results indicate that increasing the Ar flow rate, treatment time, and stirring solution improved the MB removal efficiency. In contrast, the efficiency decreased with distance and the initial MB solution. To evaluate the magnitude of these factors, a quadratic equation was developed to predict MB removal efficiency, demonstrating good agreement with the experimental data. Consequently, the relative importance of the factors based on first-order coefficients was determined as follows: treatment time > Ar flow rate > initial MB concentration > distance > stirring solution. These findings provide valuable insights for optimizing the plasma configuration and operating conditions for efficient MB removal via PLI treatment. Remarkably, 99% of MB degradation in the feed (20 mg L⁻¹) was achieved within 50 minutes of treatment, with an energy efficiency of 82.76 mg MB per kW per h, corresponding to 241.67 kW h m⁻³ for an initial MB of 20 mg L⁻¹. This process is environmentally friendly owing to its low electrical energy consumption and the fact that no chemicals are used.

Magnetorheological (MR) elastomer is classified as a smart material whose mechanical properties, such as stiffness, natural frequency, and damping capacity are tunable and controllable under the influence of magnetic field. This tunability makes it suitable for various engineering applications that require adjustable devices. Generally, MR elastomer contains magnetic particles and a matrix. Iron particles are typically used as magnetic particles in MR elastomer because of their low residual magnetism and high magnetization. Nevertheless, iron particles are prone to oxidation in a practical environment that can weaken the effectiveness of MR elastomer in terms of its field-dependent viscoelasticity. As an alternative, MR elastomer contains cobalt particles that offer better oxidative resistance and favorable electrical properties, yet their properties under oxidation have not been explored. In this work, we conducted an oxidation process using diluted 5vol% hydrochloric acid (5 vol% HCl). Two different magnetic particles (iron particles and cobalt particles) were used and tested to identify the better filler for MR elastomer subjected to oxidation conditions. The characterizations of magnetic particles were accomplished using high-resolution field emission scanning electron microscopy and energy dispersive X-ray spectroscopy (HR-FESEM and EDS) to observe the morphology and elemental compositions, and X-ray diffraction (XRD) to determine the crystallinity of magnetic particles. In addition, Fourier-transform infrared (FTIR) analysis was conducted to identify the molecular compounds of the MR elastomers. A vibrating sample magnetometer (VSM) was also utilized to obtain magnetic properties and a rheometer to measure rheological properties. The oxidation on the layer of the magnetic particles undoubtedly affected the MR elastomers’ properties showing the degradation of magnetic properties and rheological properties (storage modulus and loss modulus) for both iron particles and cobalt particles. However, cobalt particles exhibit greater oxidation resistance. It is shown that MR elastomers with cobalt particles showed a higher storage modulus and loss modulus compared to MR elastomers with iron particles both before and after oxidation. Specifically, MR elastomers with cobalt particles and MR elastomers with iron particles showed a decrement of the MR effect by 119.36% and 139.26%, respectively.

Developing cost-effective high-performance counter electrodes (CEs) is critical for improving the efficiency of quantum dot-sensitized solar cells (QDSSCs). In this study, a CNT@rGO@Cu2S composite CE was synthesized using a hydrothermal method, incorporating carbon nanotubes (CNTs), reduced graphene oxide (rGO), and Cu2S nanoparticles to enhance the charge transfer and catalytic activity. Structural characterization (XRD, Raman, FESEM, and HRTEM) confirmed the successful integration of the Cu2S nanoflowers within the rGO matrix. CNTs formed a conductive network that prevented rGO restacking and facilitated electron transport. Electrochemical analysis (CV, EIS, and Tafel polarization) demonstrated the superior electrocatalytic activity of the 6% CNT@rGO@Cu2S composite, exhibiting the highest exchange current density (J0) and lowest charge transfer resistance (Rct1), indicating efficient polysulfide redox reactions. When employed in QDSSCs with a CdS/CdSe co-sensitized photoanode, the 6% CNT@rGO@Cu2S CE achieved a power conversion efficiency (PCE) of 5.965%, surpassing those of rGO@Cu2S (5.322%) and conventional Pt-based CEs (1.96%). The superior performance is attributed to the optimized Fermi level alignment with the redox couple, enhanced charge mobility due to the CNTs, and improved electrolyte penetration.

The COVID-19 pandemic has created profound economic disruptions, significantly impacting businesses and banking systems worldwide, including Vietnam. This crisis has highlighted the need for sustainable development strategies. Michael et al. (2023) indicated that banks incorporating environmental, social, and governance (ESG) criteria gain increased investor confidence, suggesting the financial viability of ESG implementation. However, adopting ESG practices needs to be more consistent, raising questions about the factors influencing ESG implementation in Vietnamese banks and its effect on performance. This study analyses the impact of leadership characteristics, stakeholder pressures, and Big Data technology on ESG implementation in the Vietnamese banking sector. Using a quantitative approach, data was collected from various banks and analysed through partial least squares structural equation modelling (PLS-SEM) to establish causal relationships between the factors and ESG adoption. The findings reveal that leadership traits — such as strategic vision, commitment, and ESG awareness — are critical drivers of ESG policies. Stakeholder groups, including regulators, customers, and shareholders, exert substantial influence, while Big Data technology demonstrates transformative potential in facilitating ESG practices. The study concludes that ESG adoption reduces costs, improves risk management, and offers a competitive edge, positioning it as both a financial necessity and a strategic advantage for the Vietnamese banking system.

E-commerce is the process of buying and selling goods via the use of various Internet platforms. E-commerce is crucial for companies that sell products or services online because it provides a reliable, easy, and 24/7 channel of commerce for clients worldwide. Therefore, this study examines the impact of utilitarian value, hedonic value, and online reviews on client satisfaction, trust, and repurchase intentions in e-commerce platforms. This study used the cognition-affect-conation paradigm as the theoretical basis for developing the research framework. A partial least squares method was used to verify the proposed model via Google Forms from August 2024 to September 2024, using data gathered from 297 participants who participated in online purchasing on e-commerce platforms in Vietnam. This research used an online survey because of its increasing popularity and its ease, convenience, and cost-effectiveness as a data-gathering method. The findings demonstrate that utilitarian value beneficially affected buyer satisfaction (β = .242, t = 4.121), trust (β = .202, t = 3.257), and repurchase intention (β = .221, t = 3.757). Likewise, hedonic value positively impacted consumer satisfaction (β = .281, t = 3.894), trust (β = .446, t = 6.122), and repurchase intention (β = .268, t = 3.753) on e-commerce platforms. Moreover, online client reviews had a beneficial impact on consumer satisfaction (β = .182, t = 3.463) and trust (β = .145, t = 2.570). Additionally, client satisfaction (β = .215, t = 4.064) and trust (β = .215, t = 4.064) positively influenced repurchase intention. AcknowledgmentThe author acknowledges Industrial University of Ho Chi Minh City that supported this study.

This study investigates lipid antioxidants derived from bovine hemoglobin as alternative preservatives for meat products using a joint statistical modeling and experimental approach. A machine learning‐enabled three‐dimensional quantitative structure–activity relationship (3D‐QSAR) model, integrating gradient‐boosting regression (GBR) with a recursive feature elimination (RFE) framework, was employed to screen 259 tripeptides from bovine hemoglobin for their antioxidant potential. A key feature of this model was the explicit definition of its Mahalanobis applicability domain and an evaluation of its impact on prediction errors. The antioxidant activities of promising peptides were assessed using multiple assays, including ferric thiocyanate (FTC), ferric reducing antioxidant power (FRAP), 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS˙ ⁺ ) radical scavenging, and thiobarbituric acid reactive substances (TBARS) assays. Among the peptides, Phenylalanine‐Proline‐5HTP‐Leucine (F‐P‐5HTP‐L, where 5HTP represents 5‐hydroxytryptophan) showed significant efficacy in delaying pork meat oxidation, achieving a TBARS value of 2.519 ± 0.113 mg malondialdehyde (MDA)/kg, comparable to BHT, which had a TBARS value of 2.472 ± 0.455 mg MDA/kg at 0.1% (w/w). Additionally, peptides Glycine‐Arginine‐Leucine (GRL), Leucine‐Arginine‐Valine (LRV), Histidine‐Arginine‐Tyrosine (HRY), and Glutamine‐Arginine‐Phenylalanine (QRF) demonstrated significant activity against linoleic acid oxidation, though less effectively than F‐P‐5HTP‐L and BHT in meat products. This study highlights the potential of F‐P‐5HTP‐L and HRY as promising natural alternatives to synthetic antioxidants, with significant implications for reducing lipid oxidation and improving the quality of meat products.

Nitrogen and sulfur co-doped carbon quantum dots (N, S-CQDs) with enhanced photoluminescence were synthesized via a hydrothermal method using citric acid and thiourea as the precursors. The optimized synthesis yielded a high quantum yield (50.14%), surpassing many previously reported N, S-CQDs, with excellent fluorescence stability and a low detection limit (LOD = 0.184 µM) for Fe³⁺ sensing. Spectroscopic analysis confirmed successful heteroatom incorporation, where C=S and C–N functional groups introduced new defect states, enhancing fluorescence efficiency. Fe³⁺-induced fluorescence quenching followed a dynamic quenching mechanism, as confirmed by Stern–Volmer analysis, fluorescence lifetime measurements, and FTIR spectral shifts. The N, S-CQDs exhibited high selectivity for Fe³⁺ over competing metal ions and demonstrated practical applications in real water sample analysis, with stable recovery rates (96.83–104.19%) in both clean and industrially polluted water. This study provides a high-QY, low-LOD Fe³⁺ fluorescence sensor that offers a balance between sensitivity, selectivity, and environmental applicability, reinforcing the potential of N, S-CQDs for real-world metal ion detection and environmental monitoring.

In recent years, there has been a marked surge in research focused on nonlinear oscillators. Among these, a particular emphasis has been placed on a class of oscillators distinguished by their concealed attractors, drawing considerable attention due to their unique characteristics. This paper delves into the exploration of an elegant oscillator belonging to this distinctive class. Despite comprising five terms and lacking equilibrium points, this oscillator displays remarkably intricate dynamics. The study covers various aspects such as chaos, hidden attractors, offset boosting, and notably, different strange attractors exhibited by this oscillator. Additionally, approaches involving synchronization for such oscillators are introduced. Apart from the presentation of the novel chaotic oscillator, the synchronization of a nominal and uncertain chaotic system is evinced by the sliding mode technique (super-twisting algorithm) in the first case, and a robust controller is synthesized, respectively. The appropriate Lyapunov functions are implemented in the two synchronization strategies leading to obtain suitable control strategies to achieve fast and accurate control laws. The respective simulations are performed along with the conclusions of this work.

The influence of frequency, electric field strength, and nonthermal effects during ohmic heating (OH) on the inactivation of Escherichia coli O157:H7 in pomelo juice was investigated. Pomelo juice was inoculated with a specific density of E. coli O157:H7 and then treated with OH at frequencies ranging from 50 Hz to 20 kHz and electric field strengths of 20, 30, and 40 V/cm. The results showed that 60 and 500 Hz were more effective in inactivating E. coli than other frequencies. As electric field strength increased, inactivation also increased. Transmission electron microscopy analysis revealed that the cell membrane of E. coli O157:H7 treated with OH underwent more pronounced changes than cells treated with conventional heating (CH). OH could inactivate E. coli O157:H7 at lower temperatures and in a shorter time than CH. The nonthermal effect of OH increased the inactivation of the pathogen in pomelo juice. These findings demonstrated the potential of OH for pasteurizing pomelo juice.

The fitness sector is experiencing a swift digital shift, leading fitness businesses to emphasize customer loyalty. This research examined the impact of digital transformation on customer loyalty in fitness services and the mediating influence of customer experience on this relationship. Based on the Stimulus-Organism-Response framework and Trust-Commitment theory, the hypotheses were evaluated based on data from 312 fitness service users in Vietnam. Analysis using structural equation modeling indicated that capabilities in digital transformation and perceptions of quality, mediated by trust and commitment to the relationship, positively affect customer loyalty. The outcomes provide a clearer understanding of how digital activities, serving as stimuli, impact customer loyalty by shaping customer experience, which is facilitated by trust and commitment. The results pointed out the significance of fitness providers embracing a customer-focused digital transformation strategy, emphasizing actions that cultivate trust and encourage dedication to promote lasting customer loyalty. Fitness providers must enhance long-term relationships by increasing customer trust and commitment.

The dynamic analysis and the synchronization of fractional order memristive-discrete neural networks are presented in this research. First, a thorough dynamic analysis of these discrete neural networks is carried out. To analyze the stability utilizing Lyapunov theory, this research study starts with a stability analysis of two different types of neural networks. It is noteworthy to emphasize that, given the paucity of research on fractional-order memristive-discrete neural networks, this study analyzes and develops innovative stability and dynamic analysis. Furthermore, a synchronization technique based on fractional-order projective terminal sliding mode controller is devised for these neural network. The advantage of the proposed control strategies among other strategies found in the literature is that the settling time is significantly fast than a single projective synchronization scheme or a single sliding mode control synchronization techniques. The significance of the numerical experiments is that they validate the theoretical results obtained in the paper.

The Ag/UU-200@g-C 3 N 4 composite exhibited excellent photocatalytic performance for the degradation of RB19 dye under visible light. The characterizations of materials were confirmed by XRD, FT-IR, UV-Vis DRS, SEM, TEM, EDX, and XPS analyses. The composite demonstrated enhanced visible-light absorption and a reduced bandgap of 2.41 eV. The photocatalytic efficiency was optimized by tuning parameters such as NaBH 4 concentration, catalyst loading, dye concentration, and pH value. The unique electronic structure of g-C 3 N 4 , attributed to its nitrogen bonds and species—particularly the C–N = C bonds and tertiary nitrogen groups—facilitates effective charge separation. The proposed mechanism involves the generation of reactive oxygen species, primarily O 2 • ⁻ , as the main active species during degradation. The Ag/UU-200@g-C 3 N 4 catalyst exhibited notable stability and reusability, maintaining its efficacy over multiple cycles.

A one-pot green synthesis approach was developed to fabricate Ag/Ni/Fe3O4-activated carbon beads (Ag/Ni/MACB) using Brucea javanica as a natural carbon precursor. Unlike conventional powdered catalysts, these millimeter-sized porous beads enable easy recovery and reusability, addressing a key limitation in heterogeneous Fenton systems. The Fe3O4 component facilitated Fenton-like reactions, while Ni and Ag nanoparticles synergistically enhanced electron transfer and visible-light absorption, significantly boosting photo-Fenton efficiency. The catalyst achieved 96.78% enrofloxacin (ENR) degradation under optimized conditions, with radical scavenger experiments confirming that ˙OH and ˙O2⁻ were the dominant reactive species. Comprehensive characterization (XRD, SEM, TEM, BET, VSM, and FTIR) verified the uniform dispersion of Fe3O4, Ni, and Ag nanoparticles (10–50 nm) within the carbon matrix, ensuring structural stability and catalytic efficiency. The incorporation of Ag not only improved light absorption but also imparted strong antibacterial properties, effectively inhibiting Escherichia coli and Staphylococcus aureus. This dual functionality allows Ag/Ni/MACB to simultaneously degrade organic pollutants and eliminate bacterial contamination, demonstrating self-cleaning capability. The catalyst retained 83.61% efficiency after five cycles with negligible metal leaching, highlighting its long-term stability and recyclability. Additionally, the degradation pathway of ENR was elucidated, providing deeper insights into the reaction mechanism. By integrating sustainable material design, enhanced photocatalytic properties, and antibacterial action, Ag/Ni/MACB serves as a versatile and cost-effective solution for wastewater treatment, offering simultaneous pollutant degradation and microbial disinfection in a single step.

This study explores the impact of Ni, Co, Mn, and Ag doping on the optical and photoluminescence properties of ZnSe quantum dots (QDs). Structural analysis confirms successful dopant incorporation, with XRD revealing lattice strain-induced shifts. Optical studies show that Ni²⁺ and Co²⁺ induce blue shifts, while Mn²⁺ and Ag⁺ create redshifted emissions. Photoluminescence analysis demonstrates that Mn²⁺ doping enhances quantum efficiency to 49.52% via the 4T1 → 6A1 transition. Ag+-doped ZnSe exhibits blue-shifted emissions but suffers from defect-related non-radiative losses. CIE color coordinates validate tunable emissions, confirming potential applications in LEDs, displays, and bioimaging. These findings provide insights into dopant-induced band structure modifications, advancing the design of high-performance luminescent materials for optoelectronics. Copyright © 2025 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

This study delves into the axial crushing behavior of bionic rectangular and square tubes, both with and without ribs, through experimental methods. The bionic structures are meticulously fabricated by integrating thin tubes, thicker ribs, and spot welding. The crashworthiness performance is evaluated for thicker square tubes without ribs and thinner square and rectangular tubes with ribs, taking into account critical factors such as ribs, sections, and spot welding. Compared to the tube without ribs (90902), which has a higher peak crushing force (PCF) of 250.94 kN and a lower crushing force ratio (CFR) of 0.30, ribbed tubes exhibit a 43.24% lower average PCF (142.42 kN), and a 58.47% higher average CFR (0.476). Ribbed square tubes outperform their rectangular counterparts in specific energy absorption (SEA), with BRST1 specimens achieving a 42.94% higher mean SEA (12.75 kJ/kg) compared to BRRT1 specimens (8.92 kJ/kg), despite the latter having a higher PCF. Consequently, the study underscores the effectiveness of incorporating thin tubes with thicker ribs and spot welding in the construction of energy absorbers.

This research seeks to explore the connections among external innovation sources, the integration of digital technologies, customer engagement, internal innovation sources, and their influence on perceived organizational agility and market dynamics within emerging market e-commerce. The research method employed in this paper is systematic and includes the use of well-developed structured questionnaires distributed among e-commerce vendors and the logistics workforce. As a result, PLS-SEM was used to analyze the investigated factors and examine the relationships between the variables and the ability of governmental policies to influence them. Field evidence indicates that external sources of innovation and the application of digital technologies significantly enhance the firm's ability to respond to the market. At the same time, internal resources are beneficial but with some complexities. Absorptive policies are a crucial enabling system that sustains or hinders the diffusion of innovative ideas. The study highlights the importance of collaborative work between organizations, the integration of technologies, innovations into processes enhancing work, and supportive governmental policies. The findings reveal several managerial, social, and theoretical implications that contribute to the increased flexibility and growth capability of e-commerce firms in emergent markets.

Corporate social responsibility (CSR) disclosure plays a pivotal role in expanding investment opportunities, enhancing operational efficiency, and strengthening transparency and accountability to meet stakeholder demands. This study investigates the determinants influencing CSR disclosure’s extent and quality, aiming to provide a comprehensive understanding of how organizational, institutional, and stakeholder-driven factors shape transparent reporting practices. Using time-series data spanning six years (2017–2022) collected from 200 Vietnamese-listed enterprises annually, this research employs the ordinary least squares (OLS) method for quantitative analysis. The findings reveal that board independence, awards, company size, and financial performance significantly and positively influence both the extent and quality of CSR disclosure. Conversely, industry sensitivity negatively impacts CSR disclosure, while financial leverage exhibits mixed effects – positively affecting the extent but negatively influencing the quality of disclosures. Notably, company size emerges as the strongest determinant of CSR disclosure, underscoring the critical role of larger firms in driving transparent reporting practices. In contrast, industry sensitivity demonstrates the weakest effect on the extent of CSR reporting, suggesting that internal firm characteristics may outweigh industry-specific pressures. Based on these findings, the study recommends that Vietnamese regulatory bodies prioritize company size over industry type when designing CSR disclosure policies. This study provides valuable insights into the evolving dynamics of CSR disclosure in emerging markets like Vietnam, highlighting the need for context-specific strategies to enhance corporate accountability and sustainable development. AcknowledgmentThe author thanks everyone who helped make this study possible.

Efficient removal of dye contaminants from wastewater remains a significant environmental challenge. In this study, a polyethyleneimine (PEI)-modified magnetic bagasse composite was synthesized by integrating sugarcane bagasse, PEI, Fe₃O₄ nanoparticles, and glutaraldehyde as cross-linking. The synthesized material was comprehensively characterized using SEM, BET, XRD, TGA, and FTIR techniques to elucidate its structural and physicochemical properties. Adsorption experiments were performed to investigate the effects of adsorbent dosage, initial dye concentration, pH, and contact time on the removal efficiency of Yellow 4GL and Black R-S dyes. The PEI-magnetic bagasse composite (PMBC) demonstrated impressive adsorption capacities of 185.19 mg/g for Yellow 4GL and 204.08 mg/g for Black R-S. The adsorption kinetics conformed to the pseudo-second-order model, indicating that chemisorption dominated the process, driven by electrostatic interactions and hydrogen bonding between the amino groups of PEI and the sulfonate groups of the dyes.