Published: 2023-07-14

Effects of different plant growth regulators as the foliar application on growth and flower quality of potted rose (Rosa chinensis Jacq. cv. Nhung)

Pham Thi Phuong Thao, Le Van Hoa, Le Thanh Toan, Trinh Van Ban
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This study was conducted to evaluate the different concentrations of Naphthalene acetic acid (NAA), Benzyladenine (BA) and Gibberellic acid (GA3­) as foliar applications on growth and flower quality of potted rose Nhung (Rosa chinensis Jacq. cv. Nhung). The experiment was constructed in a completely randomized design, that included seven treatments, such as control (sprayed water), NAA, BA and GA3 at two different concentrations of 25 and 50 ppm, in six replications, with one plant/pot for each replication. The chemical solutions were applied three times at an interval of fifteen days. The results revealed that some plant growth regulators increased the growth and flowering time of rose cv. Nhung. Using pre-harvest foliar sprays of NAA and BA at 25 and 50 ppm concentrations showed maximum bud diameter, flower diameter and flowering duration as compared with the control treatment. The concentration of  GA3 foliar application at 25 ppm increased plant growth (the height of flowering branches and Spad values) without affecting flower quality values and the flowering duration in comparison with the control treatment.

Agrobacterium-mediated transformation of Nang Thom Cho Dao, an indica rice variety

Nguyen Van Manh, Do Tien Phat, To Thi Truc Tam, Nguyen Van Toan , Huynh Ky
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Agrobacterium-mediated transformation is the most efficient method to transfer gene of interest into the plant genome. However, the transformation efficiency of this method with indica rice varieties is still low and needs to be improved. In this study, the Agrobacterium-mediated method was used to transfer reporter genes into the Nang Thom Cho Dao, an indica rice variety. Different transformation parameters, such as selection to used hygromycin at concentrations of 0, 25, 30, 40, and 50 mg/L, bacterial density, and infected duration, were tested and optimized. The results showed that 30 mg/L of hygromycin was the most appropriate concentration for selecting transgenic callus in Nang Thom Cho Dao. In addition, the highest transformation efficiency of this Nang Thom Cho Dao rice cultivar was observed at the bacterial suspension density OD600nm of 0.1, the infected duration of 20 minutes, and the 3-day co-culture period. The presence and expression of transgenes were confirmed by gus staining and PCR with specific primers for hptII and gus genes. This transformation procedure should be used for further studies in genetic engineering of Nang Thom Cho Dao and other indica rice varieties.

Effects of Titanium Dioxide nanoparticles on salinity tolerance of rice (Oryza sativa L.) at the seedling stage

Pham Thuy Trang, Danh Bao Ngoc, Do Tan Khang
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This study aimed to evaluate the effects of titanium dioxide nanoparticles on the salinity tolerance of rice. The effects of five nano titanium dioxide concentrations (0 mg/L, 25 mg/L, 50 mg/L, 75 mg/L, and 100 mg/L) on the physiological and biochemical parameters of rice were evaluated. The results showed that among three rice varieties (ST24, ST25, OM18), only ST25 grew in a better manner with the application of TiO2 nanoparticles and the optimal concentration of TiO2 nanoparticles was 50 mg/mL. It increased the shoot height by 20.07% and the survival rate of rice compared to the control. These growth-promoting effects were simultaneous with increased levels of chlorophyll, carotenoid and proline. The activities of antioxidant enzymes were improved. While activities of enzymes catalase and peroxidase increased significantly, no change in the activities of ascorbate peroxidase was observed. Finding of this study showed that titanium dioxide nanoparticles increased the salinity tolerance of rice by promoting the photosynthetic and anti-oxidative processes in rice seedlings.

The effect of environmental accounting information disclosure on financial performance of Vietnamese listed industrial firms: The moderating role of Leverage and Big4

Nguyen Thuy An, Le Phuoc Huong, Nguyen Huu Dang, Luong Thi Cam Tu, Ngo My Tran
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Environmental Accounting Information Disclosure (EAID) is the most recent novelty in corporate non-financial information reporting practice. This study aims to evaluate the effects of EAID on the financial performance of Vietnamese enterprises. The population of this study comprises listed companies in the industrial sector on the Ho Chi Minh Stock Exchange for the period of five years (2017–2021). The research employed a purposive sampling technique and some analysis techniques, such as content analysis and regression analysis, including Ordinary Least Squares, Fixed Effects Model, Random Effects Model, and Feasible General Least Squares. The final regression results show a positive effect of EAID on profitability. Specifically, as a moderating variable, leverage weakens the relationship when financial performance is measured by ROA and ROE, whereas the quality of financial statements is assured by the Big 4, which strengthens the nexus between EAID and ROE. The study cannot confirm the negative moderating variable of the duality of the CEO position in the relationship. The research gives implications for improving financial performance with increased EAID and some future research directions.

The impact of the free cash flow and the firm’s life cycle on dividend policy: Evidence from Vietnam’s listed firms

Chau Anh Vu
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The decision on dividend policy is one of the most important decisions in the financial sector which still has inconsistent results leading to various debates among researchers. This study aims to examine the impact of the factor of the free cash flow (FCF) and the firm’s life cycle (RE/TE) on the dividend payout ratio. A panel data of 110 listed firms from the period 2014 - 2020 on Ho Chi Minh stock exchange (HOSE) are used to test the hypothesis. The estimators used to analyze the data are fixed effect model (FEM), random effect model (REM), and then generalized method of moments (GMM) applied to remedy the common errors of panel data. The finding shows that firms in the growth stage will use the free cash flow to invest in a profitable project instead of paying dividends to shareholders. In the meantime, other firm characteristics such as firm size, return on assets, and debt have a positive impact on the dividend payout ratio.

Synthesis and application of Fe3O4/GO/PVP composite material for methylene blue adsorption

Luong Huynh Vu Thanh, Thi Nhu Y Nguyen, Nguyen Van Kiet, Ngo Truong Ngoc Mai, Nguyen Nhu Ngoc, Ly Phuong Thao
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In this study, Fe3O4/GO/PVP (FGP) was successfully synthesized and efficiently applied for absorbing methylene blue. First, GO was synthesized by Hummer’s method from waste home-batteries. The chemical co-precipitation method was used to fabricate Fe3O4/GO from a mixture solution of GO, Fe3+, Fe2+. Polyvinylpyrrolidone PVP was selected to functionalize Fe3O4/GO and form Fe3O4/GO/PVP for improving dispersibility purpose in aqueous solution. The obtained Fe3O4/GO/PVP was characterized by XRD, FT-IR, BET, FE-SEM, UV-Vis techniques. Moreover, the effecting factors as pH, time adsorption, initial concentration of methylene blue were conducted. Adsorption isotherm models were also identified. The results showed that specific surface area of FGP-3 was 70.0 m2.g-1, the Freundlich isotherm model was suitable and the Dubinin - Radushkevich isotherm model showed that the process was physical adsorption. The maximum capacity (qmax) was 30.4 mg.g-1. These findings prove Fe3O4/GO/PVP as an inexpensive and efficient adsorbent for removal of cationic dyes.

Design of a smart doorbell for a leader’s office with availability status notification and visitor recognition features

Nguyen Khac-Nguyen , Chanh-Nghiem Nguyen, Bui Huu-Danh, Tran Minh-Tuong , Chanh-Nghia Lam, Truong Quoc Bao, Nguyen Hoang Dung, Nguyen Chi Ngon
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Smart doorbells have become a critical component of smart homes and modern offices. However, a smart doorbell, particularly designed for a leader’s office, has not been introduced. In this study, a smart doorbell is developed for a leader’s office. The system includes an application that allows availability status notification on the doorbell module and voice communication with the visitor from inside the office based on a private Wi-Fi network without an Internet connection to prevent the leader from potential privacy and security issues. It also features a live video capture of the visitor with face recognition by implementing a MobileNet model. In training and testing this model, 1,549 free face images of 125 people were augmented to generate training, validation, and testing datasets of 9,185, 2,500, and 5,000 face images, respectively. An additional authentication testing dataset of 1,068 AI-generated face images was also used to evaluate the system’s False Acceptance Rate (FAR). A high confidence level of 0.945 was selected for the developed MobileNet model to obtain zero FAR and high accuracy, recall, and F-score values of 0.960, 0.960, and 0.978, respectively. Therefore, the proposed doorbell could be used for an office leader, showing potential use for biometric authentication.

Identify and predict incorrect prices by Machine Learning Model

Lam Thanh Toan, Nguyen Xuan Ha Giang, Nguyen Hoang Thuan
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Electronic commerce (e-commerce) brings huge advantages to businesses for selling products through multiple online shops. However, companies have difficulties in supervising the prices of products set by different retail shops on e-commerce platforms. Addressing these difficulties, we suggest a method to identify and predict products that sell at incorrect prices using a machine learning model combined price analysis. The study uses four machine learning models: K-nearest Neighbor (KNN), Random Forest (RF), Support Vector Machine (SVM), and Multinomial Naive Bayes (MNB) and two text-based information extraction methods: BoW and TF-IDF to find to the best method. The research results show that the RF model and text-based information extraction method by the BoW provide more average accuracy than other specific models, when experimenting on the filter dataset the average accuracy after 10 runs are RF: 98.06%, SVM: 83.92%, MNB: 92.21%, KNN: 94.06%. Experimental results on the product dataset have an accuracy of RF: 83.02%, SVM: 55%, MNB: 79.33%, KNN: 79.36%.

Theoretical and experimental assessment of the effect of adhesive bond thickness on the flexural capacity of CFRP strengthened beams

Ebuka Nwankwo, TrustGod John
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Carbon Fiber Reinforced Polymer (CFRP) is a material of choice in the structural strengthening of reinforced concrete (RC) elements. In order to strengthen RC elements, CRFP is bonded externally to RC elements using adhesives.  This paper investigates the effect of varying adhesive bond thickness on the moment capacity of CFRP strengthened RC beams in flexure. Thirty-eight (38) Reinforced concrete beams (1.2m length) were cast in the laboratory and their failure loads and corresponding moment capacities obtained when the adhesive bond thickness between the CFRP wraps and RC beams were varied. This paper examines the comparison between flexural moment capacities obtained experimentally and the predicted moment capacities using a theoretical procedure set out in AC440-2R-17 after structural strengthening with CFRP. It was observed that the adhesive thickness had a significant effect on the flexural capacity of strengthened beams. As the adhesive thickness increased beyond certain thresholds, the flexural capacity of strengthened beams reduced. At the optimum adhesive thickness threshold, the ACI 440-2r-17 procedures could predict to high accuracy the moment capacities of strengthened beams.

Enhancement of photocatalytic activity of TIO2 for gaseous toluene removal by simple mechanical mixing with modified zeolite

Thai Le Truong Giang, Quang Thi Hue Minh, Thai Nguyen Trieu Nguyen, Cu Hoang Minh, Le Ky Anh, Mai Hai Nghi, Le Huy Hoang, Nguyen Quang Long, Ngo Tran Hoang Duong
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A zeolite Y was modified by the microwave-assisted method (MWA) for generating mesopores and was mechanically mixed with TiO2 for photocatalytic application. The external surface area, which is represented to the mesopore, was significantly increased about 5 to 10 times in the modified zeolites compared to the parent zeolite. The catalysts were used to catalyze the gas phase photodegradation of toluene, a volatile organic compound (VOC). The photocatalytic activity and stability of the catalyst were improved when the mesoporous zeolite was presented. The mechanical mixture contained 30 wt%. TiO2 and 70 wt%. mesoporous zeolite showed the highest toluene removal efficiency.

Rural peoples’ perception, attitude, and engagement on invasive alien plants in Mount Manunggal, Cebu Island, Philippines

Jake Joshua Garces
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This research examines the perceptions of rural residents of Mount. Manunggal, Cebu Island, Philippines, on the impact of unintentionally introduced invasive alien plants, such as Mikania micrantha, Lantana camara, and Chromolaena odorata, on their livelihoods. Results suggest that their perception of the impact of each species on their livelihood varies based on criteria such as: (1) the length of time invasive alien plants have been established in the forest, and (2) the kind of household. In addition, a household study revealed that forest-adjacent homes have reacted to invasive alien plants as both victims and beneficiaries. Most of the surveyed 77 families are likely to adapt to the invaded environment because they have a history of interacting with invasive alien plants and regard them as wonderful sources of necessities if appropriately involved. In addition, the data demonstrated rural residents are eager to invest in the control and management of invasive alien plants provided the government provides standardized and adequate technical methods and skills. Without government and stakeholder assistance, decreasing the invasion is seen as impossible, and the acceptance of invasive alien plants as part of the rural ecology is foreseen as a predictable result.

Learning Management System usage: Unwrapping its potentials and drawbacks

Dyanika P. Nolasco, Danisse Mae P. Hernandez
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The pandemic has made the role that technology-based instruction, such as the use of Learning Management Systems (LMS), must play even more important. But now that face-to-face classes are resumed, it can assist instruction and the provision of distance learning. This study was founded on the idea that LMS improvement may be made by carefully examining the problems and struggles that students face. A validated and pilot-tested survey instrument and social media interviews were used to collect data for the quantitative and qualitative parts of the study, which involved 1,372 and 10 randomly chosen students, respectively. The Quirino State University’s Excellent, Accessible, Resilient, Adaptive Learning Space (QSU e-ARAL) has considerable value in terms of system, information, interaction, instructional quality, and learning quality, according to the findings, as it offers tools, features, contents, and other components that assist students' efficient and productive learning. Holistic learning has numerous advantages, but its full guarantee cannot be provided by using solely the LMS because of the technical, technological, financial, and engagement problems that students encounter when using it. With this, it is expected that the LMS will be enhanced based on user feedback in order to realize its full potential as a tool for instruction and remote learning.

An insight into non-English major learners’ task engagement from a sociocultural perspective

Nguyen Thi Khanh Doan, Trinh Quoc Lap, Pham Mai Anh
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Under the lens of a sociocultural view, this qualitative study was conducted with 83 non-English major learners at a university in the Mekong Delta to examine English learners’ task engagement. Twelve of them were further invited to be interviewed. Data were collected from class observations, learning journals, semi-structured interviews and stimulated recall. The study showed that the same task was performed differently by learners, and that the way learners implemented a given task was shaped by the negotiation between their personal and contextual factors because of their sense of agency in the situated sociocultural learning context. The study has acquired an increased insight into learners’ task engagement regarding their agency in the teaching and learning context of Vietnam from a sociocultural view.

Tertiary students’ preferences on extracurricular activities for English learning: Voices from the field of Advanced Program in Biotechnology

Le Xuan Mai, Ly Thi Bich Thuy, Le Thanh Thao
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In Vietnam, where English plays a vital role in the country’s development, extracurricular activities for English learning are considered an effective reform for enhancing citizens’ English proficiency. Previous studies have showed the positive impact of extracurricular activities on language learners’ outcomes. Yet, almost none of them has investigated students’ voices about what, how, when, and where they want these activities to be organized. This current study was employed to fill that gap in the field of biotechnology (advanced program). A 77-item questionnaire was sent to 148 students who learned biotechnology in an advanced program at a tertiary institution in the Mekong Delta of Vietnam. The results indicated the students preferred mental activities (M=4.00) to others. Moreover, they would like to travel to experience cultures from English-speaking countries (M=4.11). Further extracurricular activities were encouraged to be organized on their university campus (M=3.63). The students also preferred short-term activities at weekends to those that were organized over a long period. The study proposed a model for further extracurricular activities at the end of this writing.

The impact of personality traits on the ethical leadership, job performance and job satisfaction of public servants – A case study of the Northern public sector of Vietnam

Nguyen Danh Nam, Le Chi Phuong, Le Thi Truc Phuong
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The study aims to explore the impact of personality traits on ethical leadership, job performance and job satisfaction of public servants working in the Northern public sector of Vietnam. A quantitative approach was employed to evaluate the impact of personality traits on ethical leadership, job performance, and job satisfaction. A structured questionnaire was administered to obtain information from public servants. The SPSS 26 was used to conduct the demographic information of public servants and the SmartPLS 3.0 version was used to process the SEM. The research results showed Big Five personality traits have a positive impact on ethical leadership, job performance, and job satisfaction. Additionally, ethical leadership and job performance have a positive correlation with the job satisfaction of public servants. The research results were used to recommend leaders of State Administrative agencies in the Red River Delta to understand the personality traits of public servants to increase job satisfaction and achieve greater job performance.