CTU Journal of Innovation and Sustainable Development

Long-term cultivation effects on soil physicochemical properties in Dong Thap Province, Vietnamese Mekong Delta

Phuong Nguyen Thi — Mon, 13 Jul 2026 00:00:00 +0700

In many agricultural regions, long-term intensive cultivation has raised concerns about soil degradation and declining soil fertility, particularly in tropical lowland areas. This situation highlights the need to understand better how continuous cropping affects soil properties over time. This study aimed to investigate how prolonged continuous cultivation influences the physical and chemical characteristics of agricultural soils. Effect of 4 different long-term cultivation (<5, 5 - 10, 11 - 15, and over 15 years) on soil physico-chemical properties of farmers’ two rice - one cash crop in Dong Thap province. A total of 66 soil samples at two depths (0 - 20 and 20 - 50 cm) were randomly collected from the intensive crop area. Data showed that bulk density was higher after over 10 years of cultivation, and the soil texture of Silty Clay was observed across all crops. The results showed that the chemical properties of the soils were characterised by the low to rather low pH values (4.0 - 6.0) of the topsoil and tended to decrease gradually with depth and intensive cultivation. Unimpacted electrical conductivity (EC) in rice-crop field was recorded, while total N, P, K, soil organic carbon and CEC tended to...

Bacteriophage efficacy in controlling bacterial leaf spot disease on water spinach (Ipomoea aquatica)

Nguyen Van Linh, Le Manh Tuong, Doan Thi Kieu Tien, Thi Thu Nga Nguyen — Mon, 13 Jul 2026 00:00:00 +0700

Bacterial leaf spot disease on water spinach (Ipomoea aquatica) is common and causes severe defoliation. The bacterial pathogen responsible for bacterial leaf spot disease in water spinach was identified as Xanthomonas sp. using biochemical methods and the 16S rRNA-DNA region. In addition, this study further evaluates bacteriophages as a novel biological control approach. From twelve isolated bacteriophages, two with the largest plaque diameters, Φ8b and Φ9, were selected for evaluation of their efficacy in disease control. Results from both net house and field trials showed that these two bacteriophages, when used individually, significantly reduced disease incidence and percentage of infected leaf area compared to the control. However, the mixture of bacteriophages did not present a clear disease control effect. This study demonstrates the potential of bacteriophages for managing bacterial leaf spot disease in water spinach.

Allelopathic effects of Wedelia trilobata (L.) Hitchc extracts on weed suppression and rice seedling growth

Nguyen Thi Thuy Trang, Thi Thuy Trang Le, Dr. Nguyen The Cuong, Le Thi Ho — Mon, 13 Jul 2026 00:00:00 +0700

This research evaluates the phytotoxic potential of methanolic extracts derived from Wedelia trilobata (L.) Hitchc. against major rice weeds and rice cultivars under controlled laboratory conditions. Six plant species were tested: three dominant weed species (Leptochloa chinensis, Echinochloa crus-galli, Fimbristylis miliacea), two rice varieties (Oryza sativa L.) OM380, OM5451), and green mustard (Brassica juncea) as an indicator species. The results indicated that root growth of F. miliacea and L. chinensis was completely inhibited (100%) at concentrations between 0.12 - 0.24 g/mL, while shoot elongation was reduced by over 85%. E. crus-galli exhibited only mild inhibition or slight stimulation at lower concentrations. Both rice cultivars showed dose-dependent sensitivity, with OM380 being more responsive to lower concentrations (0.03 g/mL). Phytochemical screening confirmed the presence of high levels of phenolic and flavonoid compounds, particularly in whole plant and leaf extracts (TPC: 158.11 mg GAE/g; TFC: 260.57 mg QE/g). These allelochemicals may interfere with germination and root development of target weeds, suggesting their potential as bioherbicidal agents. The findings highlight the allelopathic potential of W. trilobata for selective weed suppression in rice agroecosystems. Further studies should focus on isolating key bioactive compounds and assessing their efficacy under greenhouse and field conditions to support the...

Enhancing tourism workforce development: A theory of planned behavior-based approach to school-enterprise collaboration in Viet Nam

An Phan Vinh, Huy Tuu Ho, Van Ngoc Nguyen — Mon, 13 Jul 2026 00:00:00 +0700

This study explores the determinants of school-enterprise collaboration in tourism human resource training in South Central Viet Nam, where tourism plays a pivotal economic role. Building on the Theory of Planned Behavior and extending it with context-specific factors, including trust, competitive advantage, perceived risk, self-efficacy, social support, and barriers, the research develops a comprehensive framework to predict collaborative intention and behavior. Data were collected from 209 leaders and faculty members at universities, colleges, and vocational schools in South Central Viet Nam between March and June 2024 and analyzed using Partial Least Squares Structural Equation Modeling. Results indicate that attitudes, subjective norms, and perceived behavioral control significantly influence collaboration intention, which subsequently predicts collaborative behavior. Competitive advantage and trust positively affect attitudes, whereas perceived risk exerts a negative effect. Policies and social requirements strengthen subjective norms, while self-efficacy and social support enhance perceived behavioral control. The model explains 41.9% of the variance in intention and 47.0% in behavior, confirming its robustness. The study contributes to TPB literature by integrating tourism-specific and institutional factors and provides practical implications for policymakers and educators to strengthen partnerships, enhance capacity, build trust, and implement supportive policies to address skill mismatches in Viet Nam’s tourism sector.

The IFRS convergence influence on financial risk and accounting fraudulent: Evidence from Thailand and Implications for Viet Nam

Nguyen Hong Thoa, Phan Thi Anh Nguyet, Nguyen Thi Hong Lieu, Vu Xuan Nam — Mon, 13 Jul 2026 00:00:00 +0700

This paper focuses on whether adopting International Financial Reporting Standards (IFRS) reduces financial risk and accounting fraud. Using 9,194 firm-year observations from Thai-listed non-financial firms between 2011 and 2022, we apply the Beneish M-Score and Altman Z-Score models to detect earnings manipulation and financial distress. The evidence shows that firms reporting under IFRS display lower M-scores, suggesting reduced earnings manipulation. However, IFRS adoption does not have a significant effect on financial distress. This is likely because while IFRS improves transparency and reduces opportunistic reporting, it does not address fundamental financial issues. Overall, our paper provides new evidence on the role of IFRS in enhancing reporting quality in emerging markets and offers implications for financial reporting policy in countries such as Viet Nam.

Integrating STEM education for sustainable development through a context-based probiotic foods project in a Vietnamese secondary school

Thuc Le Hoang, Thi Thuy Diem Huynh, Thinh Mai Phuc — Mon, 13 Jul 2026 00:00:00 +0700

This study reports on how context-based STEM (Science, Technology, Engineering, and Mathematics) education can be integrated with Education for Sustainable Development (ESD) in secondary schools through a probiotic food project. Conducted at a public high school in Can Tho City, Viet Nam, the project involved 100 tenth-grade students in designing and producing probiotic products from locally sourced ingredients. The curriculum was structured around a seven-step STEM instructional model emphasizing problem identification, interdisciplinary learning, and community relevance. Quantitative data were collected via a 15-item Likert-scale survey measuring students’ reflections on STEM competencies, sustainability awareness, and engagement. A structured teacher reflection journal provided qualitative insights into pedagogical transformation and implementation challenges. Findings indicated that students developed stronger problem-solving skills, close connections between STEM content and real-world agricultural contexts, and increased interest in sustainability-related careers. The teacher’s reflection revealed shifts from traditional content delivery to facilitation, along with practical constraints related to time and coordination. This study contributes to the growing body of literature on localized STEM-ESD integration and highlights the value of authentic, place-based learning in promoting both scientific and civic competencies among secondary school students.

EFL students’ self-directed vocabulary learning through YouTube in a mobile learning ecology

Nguyen Thi Diem Thi — Mon, 13 Jul 2026 00:00:00 +0700

This study explores how Vietnamese EFL university students engage in self-directed vocabulary learning through YouTube. Guided by Activity Theory, it examines how YouTube functions as a mediational tool in EFL students’ self-directed vocabulary learning and analyzes the key factors shaping students’ engagement with YouTube. A total of 154 journals, 22 semi-structured interviews, and four focus group discussions were used as data for the study. Thematical analysis of these triangulated data uncovers seven significant learning patterns: (1) strategic and intentional, (2) incidental and affectively engaging, (3) personalized and interest-driven, (4) integrated with multiple digital tools, (5) repetitive for reinforcement, (6) influenced by educators and influencers, and (7) spontaneous and exploratory. Generally, it was found that YouTube served not merely as a content platform but as a dynamic mediating artifact in learners’ evolving, self-regulated learning systems. This study emphasizes the efficacy of informal, self-directed vocabulary acquisition through platforms such as YouTube and contributes to discussions on digital literacy practices, learner agency, and integrated teaching frameworks.

Sustainable hempcrete wall solution and its benefits in reducing load impact on structural foundation: A case study of the Pace Building in Ho Chi Minh City

Tien Cuong Pham, Bao Ron Quach — Mon, 13 Jul 2026 00:00:00 +0700

The paper explores the benefits of reducing wall loads in construction by using lightweight hempcrete walls. The analysis focuses on the Pace Institute building located in District 1, Ho Chi Minh City. The evaluation criteria are based on load on piles transferred by both vertical and lateral (wind) loads. Load combinations are considered according to both Vietnamese (TCVN) and American standards. Two wall types- hempcrete and traditional fired clay brick are analyzed and compared to assess the advantages of using lightweight hempcrete walls. Structural analysis results indicate a significant reduction in column base loads when hempcrete walls are used in place of conventional brick walls. This reduction leads to more economical foundation design, saving both construction materials and costs. Furthermore, the use of hempcrete walls offers substantial environmental benefits, as this material is considered "carbon- negative", contributing positively to sustainable construction practices.

Removal of methyl violet from aqueous solution using chemically modified biochar derived from corncob

Minh Nguyen Nhut, Phuc Lam Thong, Tran Nguyen Phuong Lan, Dang Huynh Giao — Mon, 13 Jul 2026 00:00:00 +0700

Chemically modified corncob biochar was prepared to remove methyl violet, an organic dye, from simulated wastewater. Modern analytical methods, including SEM, FT-IR, BET/pore, etc., indicated that the porous biochar exhibited excellent characteristics, with a high specific surface area (989.14 m²/g), a large pore volume (0.61 cm³/g), and abundant functional groups on its surface. Consequently, it achieved high removal efficiency for methyl violet, with an adsorption capacity of 290.7 mg/g and a removal rate of 92.4% at high concentrations. The Pseudo-first-order and Temkin models can effectively simulate the kinetic and isotherm adsorption processes of BioPNa for MV, with R² > 0.99, indicating physicochemical composite processes as the adsorption mechanisms, including pore filling, electrostatic attractions, hydrogen bonds, and π-π interactions. The porous material also demonstrated high stability and reusability after five adsorption-desorption cycles. Therefore, it can be used as a low-cost, high-efficiency material for effectively removing methyl violet from wastewater.

A retrieval-augmented large language model for agricultural advisory on crop varieties and cultivation techniques

Mon, 13 Jul 2026 00:00:00 +0700

This study presents the design and implementation of an agricultural advisory chatbot to help farmers access reliable information on crop varieties and cultivation techniques, with a focus on rice and mango. The proposed system integrates a large language model (Gemini 2.5 Pro) with a Retrieval-Augmented Generation architecture to mitigate hallucination and improve factual accuracy in domain-specific responses. The knowledge base is constructed from authoritative agricultural technical documents, including crop variety descriptions, cultivation procedures, and pest and disease management guidelines. These materials are systematically preprocessed, segmented, and indexed in the Qdrant vector database to enable efficient semantic retrieval within the Retrieval-Augmented Generation pipeline. To enhance retrieval robustness, the system employs a hybrid search strategy that combines keyword-based retrieval and dense vector search, followed by a Cross-Encoder re-ranking module to optimize contextual relevance before response generation. System performance is evaluated using the Retrieval Augmented Generation Assessment framework. Experimental results demonstrate high reliability, with a Faithfulness score of 91.43% and an Answer Relevancy score of 95.52%. The findings indicate that the proposed approach can deliver accurate, context-aware, and practically applicable agricultural recommendations, highlighting its potential to support digital transformation and AI-driven solutions in smart and sustainable agriculture.

Reconstruction of optimal weld seam trajectory for three axis robot using deep learning and quadratic regression approaches

Mon, 13 Jul 2026 00:00:00 +0700

This study proposes a method for the integration of a segmentation model with non-linear regression to construct weld-seam trajectories. First, the weld is precisely segmented using the YOLOv8 model. Then, its boundary pixels are extracted right after and termed SEG points. The 48, 24, and 16 SEG points are utilized as the input for regression models to estimate the weld seam center-line. Both linear and non-linear (quadratic) regression models are assessed using different types of weld images. The experimental results show that the average segmentation performance and training accuracy of the YOLO model are 94%. Additionally, both linear- and nonlinear regression models can estimate similar weld seam profiles. It is worth noting that the more the SEG points are utilized, the higher the accuracy is. However, if a number of SEG points increase, the processing time increases too. Therefore, 24 SEG points are enough for the precise estimation of the weld seam trajectory. It demonstrated that the proposed approach achieves a mean absolute trajectory error of 0.24 mm at 2.9 FPS for the end-to-end pipeline by using the Ampere GPU of NVIDIA Jetson Nano (input 416×416, FP16). Moreover, estimated weld seam trajectory is transformed into the absolute coordinate for...

Effects of purple rice ratio on anthocyanin, antioxidant activity and physicochemical characteristics of extruded snack

Pham Truong Thinh Le , Minh Tri Nhan — Mon, 13 Jul 2026 00:00:00 +0700

Purple rice is rich in anthocyanins, which possess antioxidative properties and may help prevent cancer and diabetes. Extrusion is a high-temperature, short-time thermal process designed to minimize nutrient degradation. This study aimed to evaluate the effects of varying purple rice to ST25 ratios (20:80, 25:75, 30:70, and 35:65) on the physicochemical and sensory properties of extruded purple rice snacks. The evaluated parameters included hardness, color value (L*), water absorption index (WAI), water solubility index (WSI), density (d), expansion, rheology, anthocyanin, and antioxidant activity (DPPH, 2,2-diphenyl-1-picrylhydrazyl), sensory attributes. Increasing the purple rice content in extruded snacks resulted in a darker color, greater hardness, and lower expansion ratio, likely due to the impact of fiber on starch gelatinization. Water absorption decreased, while water solubility increased. Pasting properties were reduced, whereas anthocyanin content and antioxidant activity increased, highlighting potential health benefits. Incorporating 30% purple rice enhanced both anthocyanin (3.73mg/100gDW), DPPH (1.38 mgTE/gDW) and hardness (34.31 N), expansion ratio (1.71), offering insights for developing purple rice-based snacks with optimal sensory attributes, with all values about 4.22/5.

Environmental impacts on water quality due to structural measures: A case study in Hung My commune, Chau Thanh district, Tra Vinh Province, Viet Nam

Dr. Nguyen Tan Hung, Dr. Nguyen Thi Tuyet Nga , Ngo Anh Kiet Ly — Mon, 13 Jul 2026 00:00:00 +0700

Saltwater intrusion in the Vietnamese Mekong Delta has been significantly aggravated by both human development and adverse climate change. To curb salinization, local authorities rely heavily on structural measures (dikes, sluice gates, reservoir canals), yet their long-term environmental trade-offs remain underexplored. This study examines such environmental impacts and prioritization of measures in Tra Vinh province, Viet Nam. The research process combined field sampling of key water quality indicators at 25 sites, principal component analysis (PCA) to distil the main drivers, and in-depth interviews with ten risk-management experts. The findings reveal a potentially critical trade-off: measures provide operational benefits in reducing immediate intrusion, but this comes at the cost of elevated pollutant concentration and long-term degradation. This is evidenced by severe ecological stress, with many samples exceeding safe thresholds for DO, ORP, and TDS. Furthermore, the analysis confirmed strong interdependencies among conductivity, salinity, and total dissolved solids (correlation > 0.97). These results indicate the need for additional research on the ecosystem impacts of physical defenses, as well as consideration of non-structural approaches, including policy innovation, community engagement, and adaptive governance to support sustainable risk management against SI.

Synthesis pathway of biomass-derived 5-chloromethylfurfural for conversion and obtaining high concentration 2,5-dimethylfuran

Phuoc Lu Hue — Mon, 13 Jul 2026 00:00:00 +0700

The rapid depletion of fossil-based resources, together with the increasing global energy demand, has stimulated intensive research into renewable alternatives. Among these, biomass-derived fuels have emerged as highly promising candidates, with particular attention given to furan derivatives for their versatile chemical reactivity and potential as liquid transportation fuels. While the production of 5-hydroxymethylfurfural (HMF) has been extensively studied, the synthesis of 5-chloromethylfurfural (CMF) has recently attracted growing interest as a novel platform molecule. CMF offers several advantages over HMF, including milder reaction conditions, lower polarity that facilitates separation in organic media, and the presence of chlorine as an excellent leaving group, enabling efficient downstream transformations. Notably, CMF can be converted into high-value compounds such as 2,5-dimethylfuran (DMF), a biofuel with favorable physicochemical properties for transportation applications. This review highlights recent advances in CMF production from lignocellulosic biomass, synthetic strategies for its valorization into DMF and other value-added chemicals, as well as the feasibility of scaling up these processes toward industrial implementation.

An assessment of water management to cope with saltwater intrusion: A case study of Chau Thanh district, Ben Tre province, Viet Nam

Quoc Thanh Vo, Huynh Vuong Thu Minh, Thi Phuong Linh Vo, Anh Minh Nguyen — Mon, 13 Jul 2026 00:00:00 +0700

Water security and agricultural productivity in the Vietnamese Mekong Delta are at risk due to several water-related issues, most notably saltwater intrusion. Using historical data from 2011–2018 at 21 monitoring stations, this study applied percentile-based spatial interpolation to map saltwater intrusion at the 1 percent, 10 percent, and 50 percent salinity percentiles. Results reveal that extreme events (1st percentile) affect 51% of the district’s area with salinity >4 g/L, while typical years (50th percentile) affect 16% of the area, with eastern communes most vulnerable. The current irrigation system, comprising 13.2 km of canals, 79.4 km of embankments, and nine sluices, remains incomplete, thereby limiting control of saltwater intrusion. A planned network of 33 sluices by 2030 aims to enclose the system, supported by tailored water management strategies, including sluice operations, water transfer via the Ba Lai River, and storage of 12 million m³ in canals. These measures could ensure freshwater availability for orchards and domestic use. The study underscores the urgency of finalizing infrastructure and planning storage zones to address dry season shortages, offering insights for sustainable water management in the Vietnamese Mekong Delta under climate change pressures.

Effects of natural extracts combined with Burkholderia spp. on the growth, yield, and quality of lettuce (Lactuca sativa Muir) under greenhouse conditions

Mon, 13 Jul 2026 00:00:00 +0700

This study aimed to evaluate the effects of natural extracts and Burkholderia spp. bacterial strains on the growth, yield, and quality of lettuce (Lactuca sativa cv. Muir) under greenhouse conditions. The experiment was conducted using a completely randomized block design with two factors: (A) two natural extracts (catfish waste extract FE and soybean oil cake extract SE), and (B) three bacterial strains (MP1, MP2, MP3), and no bacterial strain. A total of 8 treatments were set up, with 6 replications per treatment. Agronomic parameters were recorded at 15, 35, and 55 days after sowing (DAS) to evaluate the growth-promoting effects of the extracts and bacterial strains on Muir lettuce. The yield components and quality parameters were determined at 55 DAS. The results demonstrated that the FE extract was more effective than the SE extract (p<0.01), enhancing plant growth, producing marketable head weights of 300 g.plant^-1 and 287 g.plant^-1, respectively. Similarly, the MP1 strain significantly enhanced the growth and the marketable head weight. The application of natural extracts with bacterial strains reduced postharvest weight loss to below 5% after a 15-day storage period...