Effects of cellulose nanofibers on soil water retention and aggregate stability

Innovative solutions that address global challenges such as water scarcity and soil erosion are critical for maintaining sustainable agriculture. Due to their water-absorbing and soil-binding properties, cellulose nanofibers (CNF) can be applied to soil to enhance soil water retention and aggregate stability. In this study, we analyzed the effects of the drying temperature, dosage, irrigation water quality, and soil type on the efficacy of CNFs. Our results revealed that CNF dried at 5 degrees C is more effective at absorbing water than others, and adding 1% CNF enhanced soil water content up to 98%. The CNF samples absorbed water due to their hydrophilic molecular groups and morphological structure, as confirmed by Fourier-transform infrared spectroscopy and scanning electron microscopy. CNF addition increased the soil volumetric water content and prolonged water retention by 22 days in the paddy soil samples, highlighting its potential for drought-prone areas. Furthermore, irrigation water quality, such as pH and cation values, influenced the interactions between CNF and water molecules, suggesting adjustments to the water retention curve. In its hydrated state, CNF promotes colloid flocculation and binds to soil particles, thereby strengthening the bonds crucial for aggregate formation and stability. CNF enhanced macro-aggregate formation by up to 48% and 59% in the masa and paddy soil samples, respectively. Our study emphasizes the potential of CNF for water conservation, soil health, and overall agricultural sustainability

Factors Affecting Firms’ Performance: The Case of Vietnam construction firms

In the context of Vietnam's international economic integration, improving the performance of enterprises is increasingly important because it not only affects businesses but also affects the development prospects of the economy. The purpose of the paper is to consider the impact of factors on the performance of listed construction companies in the period of 2012-2018. By means of an empirical analysis, this study uses Eviews econometric software and table data techniques. This study found the factors that positively impact on performance are asset structure, capital structure and firm size that negatively impact the performance of Vietnam listed construction firms. These findings support business administrators in selecting appropriate business and production plans to increase the operating performance of businesses in the construction industry. Keywords: Profitability, construction firms DOI: 10.7176/RJFA/11-2-15 Publication date: January 31st 202

Effects of steel corrosion to BFRP Strengthened columns under eccentric loading

The experiment consists of twenty-four mid-scale rectangular RC columns (200x200x800mm) strengthening by BFRP sheets and research variables include: BFRP layer (0, 1, and 3 layers); eccentricity (25mm and 75mm); and 4 levels of steel corrosion. The results reveal that SEL (ratio of ultimate load of strengthened member to that of corresponding controlled member) is direct proportion with steel corrosion while SEV (ratio of ultimate vertical displacement of strengthened member to that of corresponding controlled member) is inverse proportion with steel corrosion; SEL slightly increases with the increase of BFRP layer and eccentricity; but SEV decreases noticeably with the increase of BFRP layer and eccentricity. In addition,the interaction between FRP sheets, stirrups, and longitudinal reinforcement in steel degraded BFRP strengthened columns is very strong.However, column design basing on current design manuals and codes as ACI 440.2R and CNR DT 200R1 has not mentioned this affect. Thus, the load capacity prediction of column being strengthened by BFRP sheets should include levels of steel corrosion for reality, reasonable, and integral of the design

Effects of steel corrosion to BFRP Strengthened columns under eccentric loading

The experiment consists of twenty-four mid-scale rectangular RC columns (200x200x800mm) strengthening by BFRP sheets and research variables include: BFRP layer (0, 1, and 3 layers); eccentricity (25mm and 75mm); and 4 levels of steel corrosion. The results reveal that SEL (ratio of ultimate load of strengthened member to that of corresponding controlled member) is direct proportion with steel corrosion while SEV (ratio of ultimate vertical displacement of strengthened member to that of corresponding controlled member) is inverse proportion with steel corrosion; SEL slightly increases with the increase of BFRP layer and eccentricity; but SEV decreases noticeably with the increase of BFRP layer and eccentricity. In addition,the interaction between FRP sheets, stirrups, and longitudinal reinforcement in steel degraded BFRP strengthened columns is very strong.However, column design basing on current design manuals and codes as ACI 440.2R and CNR DT 200R1 has not mentioned this affect. Thus, the load capacity prediction of column being strengthened by BFRP sheets should include levels of steel corrosion for reality, reasonable, and integral of the design

Induced systemic resistance against rice grassy stunt virus – a promising field for ecological rice production: Research article

Most rice protection methods have currently used toxic chemicals to control pathogens and pests, which leads to environmental pollution. Systemic acquired resistance (SAR) taking advantage of natural defence reaction of plants could be proposed as an alternative, ecologically friendly approach for plant protection. Its application into rice production could minimize the chemicals quantity used and could contribute to the decrease of environmental pollution and the development of sustainable agriculture. The research was conducted to select the most effective chemical and suitable method to improve the health of rice plants infected by grassy stunt disease in net-house of Can Tho University. SAR chemicals were used at very low concentrations (in mM). Results showed that the height of rice plants treated with SAR chemicals was higher than that of plants untreated. Besides, the number of diseased plants was reduced and the ratio of firm grain and yield increased when plants were applied by SAR. Among the used substances, oxalic acid provided the best systemic acquired resistance. With oxalic acid, seed soaking was better than seed coating in systemic acquired resistance against rice grassy stunt disease.Hầu hết các phương pháp sản xuất lúa hiện nay đều sử dụng các hóa chất độc hại trong việc phòng trừ bệnh và côn trùng gây hại, nên dẫn đến ô nhiễm môi trường. Kích thích tính kháng lưu dẫn giúp kích hoạt cơ chế tự nhiên kháng bệnh của cây có thể là giải pháp bảo vệ thực vật thay thế an toàn với môi trường. Việc ứng dụng tiến bộ này vào trong sản xuất lúa có thể làm giảm lượng hóa chất sử dụng, đóng góp vào việc giảm thiểu ô nhiễm môi trường và sự phát triển của một nền nông nghiệp bền vững. Nghiên cứu đã được thực hiện tại nhà lưới trường Đại học Cần Thơ để tuyển chọn hóa chất và phương pháp sử dụng hóa chất để tăng cường sức khỏe giúp cây lúa vượt qua bệnh vàng lùn. Hóa chất kích kháng được sử dụng ở một nồng độ rất thấp (đơn vị là mM). Kết quả cho thấy chiều cao cây lúa khi xử lý chất kích kháng tốt hơn so đối chứng không xử lý. Bên cạnh đó, số cây lúa nhiễm bệnh giảm, tỉ lệ hạt chắc và năng suất tăng khi cây lúa được xử lý với chất kích kháng. Trong số các chất kích kháng đã sử dụng, acid oxalic cho hiệu quả vượt trội. Với chất acid oxalic, phương pháp ngâm hạt cho hiệu quả kích kháng tốt hơn phương pháp áo hạt

Van Der Waals and Casimir Interactions of Some Graphene, Material Plate and CNTs Systems

The Van der Waals and Casimir interactions between graphene and a material plate are studied by using the Lifshitz theory and approximate expressions for the free energy and force. The reflection properties of electromagnetic oscillations on graphene are governed by specific boundary conditions imposed on the infinitely thin positively charged plasma sheet, carrying a continuous fluid with some mass and charge density. The obtained formulas are applied to the cases of a graphene interacting with Au plate. We calculated also the Casimir interaction between carbon nanotube single wall and Au plate. The comparision with other recently obtained theoretical results are made and the generalizations to more complicated carbon nanostructures are discussed

pH-Dependence of the Optical Bio-sensor Based on DNA-carbon Nanotube

In 2006, Daniel A. Heller et al. [1] demonstrated that carbon nanotubes (CNNTs) wrapped with DNA can be placed inside living cells and detect trace amounts of harmful contaminants using near infrared light. This discovery could lead to new types of optical sensors and biomarkers at the sub cellular level. The working principle of this optical bio-sensor from DNA and CNNTs can be explained by a simple theoretical model which was introduced in [3]. In this paper, the pH-dependence of DNA and the pH-dependence of solution around CNNTs are shown by using data analysis method. By substituting them into the same model, the pH-dependence of DNA-wrapped CNNTs was elicited in this paper. The range of parameters for workable conditions of this bio-sensor was indicated that the solution should have pH from 6 to 9 and the concentration of ions should be more than a critical value. These results are according to the experimental data and the deduction about pH and salt concentration in solution. They are very useful as using such a new bio-sensor like this in living environment

Impact of Corporate Social Responsibility to Firms' Performance in Southern Enterprises of Vietnam

This study is aimed to evaluate the impact of corporate social responsibility (CSR) on firms' performance by developing the role of mediating variables such as corporate reputation (CR) and customers' purchasing intention (CPI). We use qualitative and quantitative technique such as Smart PLS SEM to analyze the data of the corporate in the South of Vietnam in 2019. The findings suggest a positively significant impact of corporate social responsibility on firms' performance through mediating role of CR and CPI. This study contributed empirical work in the literature of corporate social responsibility and firms' performance. The outcomes of this study can be used by entrepreneurs, top management as an attempt to boost the performance of the corporate. A mediating role of corporate reputation (CR) and customers' purchasing intention (CPI) as a value-added contribution to this study and can be strengthened more in future research.   Keywords: Corporate Social Responsibility, Corporate Reputation, Purchasing Intention; Firms' Performance. JEL Classification: M31     DOI: https://doi.org/10.32479/irmm.990

Factors Affecting Business Performance: Expanding Theoretical Measurements

Purpose: The article aims to expand a scale system of factors that impacts on business performance.   Theoretical framework: The paper based on the empirical data collected from various types of participants, including accountants (for information providing), managers (for decision-making), sales staff (for work), and lecturers (for research) in Vietnam.   Design/methodology/approach: By descriptive and comparative statistical analysis of SPSS 20 software with 124 valid observations, the survey has proposed the scale system of influencing factors (03 groups of external factors, 05 groups of internal factors) and business performance measures (10 financial and 11 non-financial indicators).   Findings: This study points out the different evaluations according to the demographic features of survey subjects on the group of financial indicators. Specifically, the group of accountants (representing information providers) obtains a lower score than the group of information users. Likewise, the post-graduated participants show stricter assessments of financial indicators in comparison to the rest of the group.   Research, Practical & Social implications: These results suggest the scale system for measuring influencing factors toward business performance in enterprises for further research.   Originality/value: The value of the study is providing an expansion of the factors affecting the efficiency of an enterprise and points out a commonly used set of financial performance measurement indicators. Research results provide useful references for research on related issues