Scale In Vietnam Research Articles

Research on isolation, identification, and determination of suitable conditions for the cultivation of albino <i>Cordyceps militaris</i> SHBTD fruiting bodies

Cordyceps militaris is a valuable fungus that is well-known in many Asian countries. The fruiting bodies of C. militaris are commonly used in traditional medicine and the production of functional foods. Currently, C. militaris mushrooms are being cultivated on a large scale in Vietnam, yielding the characteristic yellow-orange fruiting bodies typical of C. militaris. In the mushroom cultivation industry, C. militaris is one of the most highly valued species. The yield and quality of the fruiting bodies are greatly dependant on the strain source. Therefore, the search for new strains of C. militaris with high productivity, quality, and uniqueness is always of interest to scientists. This study has isolated and identified the albino strain C. militaris SHBTD based on morphological characteristics and the rDNA ITS region gene sequence. The optimal conditions for fruiting body formation of the SHBTD strain are MT6 medium, a temperature of 22°C, a humidity of 90%, a light intensity of 500 lux (12 hours/day), and 65 days of cultivation. Additionally, this study determined that the albino strain C. militaris SHBDT carrying the single Mating-type (MAT) gene (MAT1-1-1), could provide stable yield and quality of fruiting bodies over 5 consecutive cultivation generations. The obtained results demonstrate the potential applications of the C. militaris SHBTD in the industrial-scale production of unique and high-value mushroom products.

Technical Efficiency and Returns to Scale in Vietnam’s Agriculture: Stochastic Output Distance Function Approach

Technical Efficiency and Returns to Scale in Vietnam’s Agriculture: Stochastic Output Distance Function Approach

Chemical Composition, Larvicidal and Molluscicidal Activity of Essential Oils of Six Guava Cultivars Grown in Vietnam.

Diseases transmitted by mosquitoes and snails cause a large burden of disease in less developed countries, especially those with low-income levels. An approach to control vectors and intermediate hosts based on readily available essential oils, which are friendly to the environment and human health, may be an effective solution for disease control. Guava is a fruit tree grown on a large scale in many countries in the tropics, an area heavily affected by tropical diseases transmitted by mosquitoes and snails. Previous studies have reported that the extracted essential oils of guava cultivars have high yields, possess different chemotypes, and exhibit toxicity to different insect species. Therefore, this study was carried out with the aim of studying the chemical composition and pesticide activities of six cultivars of guava grown on a large scale in Vietnam. The essential oils were extracted by hydrodistillation using a Clevenger-type apparatus for 6 h. The components of the essential oils were determined using gas-chromatography-mass-spectrometry (GC-MS) analysis. Test methods for pesticide activities were performed in accordance with WHO guidelines and modifications. Essential oil samples from Vietnam fell into two composition-based clusters, one of (E)-β-caryophyllene and the other of limonene/(E)-β-caryophyllene. The essential oils PG03 and PG05 show promise as environmentally friendly pesticides when used to control Aedes mosquito larvae with values of 24 h LC50-aegypti of 0.96 and 0.40 µg/mL while 24 h LC50-albopictus of 0.50 and 0.42 µg/mL. These two essential oils showed selective toxicity against Aedes mosquito larvae and were safe against the non-target organism Anisops bouvieri. Other essential oils may be considered as molluscicides against Physa acuta (48 h LC50 of 4.10 to 5.00 µg/mL) and Indoplanorbis exustus (48 h LC50 of 3.85 to 7.71 µg/mL) and with less toxicity to A. bouvieri.

STRENGTHENING ECONOMIC TIES: THE IMPACT AND POTENTIAL OF SOUTH KOREAN FOREIGN DIRECT INVESTMENT IN VIETNAM

Economic cooperation has been a key pillar of the relationship between South Korea and Vietnam, with the two nations joining numerous bilateral and multilateral cooperation agreements. Theeconomic ties between the two contries have been strengthened significantly through the Korea-Vietnam Free Trade Agreement (KVFTA), which hasprovided a framework for promoting economic cooperation, trade, and investment, fostering stronger and more effective mutual relations between the two nations. As of 2022, Korea's investment scale in Vietnam has reached approximately 80 billion USD, fueling Vietnam's economic growth, employment opportunities, and technology transfers. The paper examines the legal basic for promotingforeign direct investment in Vietnam and delves into the patterns of Korea's FDI in Vietnam,highlighting the expected expansion of Korean firms' investments. The research assesses the potential opportunities and challenges associated with South Korean foreign direct investment in Vietnam. Finally, the study offers several recommendations aimed at mitigating negative outcomes while maximizing the positive impacts of this bilateral relationship within the current context.

DESIGN AND MANUFACTURE A BANANA FIBER EXTRACTION MACHINE FOR SMALL AND MEDIUM-SCALE HANDICRAFT PRODUCTION

Currently, by-products from banana trees such as banana sheath and leaves are discarded, which is very wasteful and causes environmental pollution. However, in the world, these materials are considered a significant resource that can be used to produce natural fibers and create handicraft products that are aesthetically valuable, economically viable, and environmentally friendly. This article introduces the research results on designing and manufacturing a banana fiber extraction machine for the production of handicrafts on a small to medium scale in Vietnam. The machine was designed through calculations, model building, and software testing before being manufactured and assembled. After assembly and completion, the banana fiber extraction machine was tested under no load and under load to evaluate its fiber processing capability. Three different processing modes corresponding to different motor speeds of 750 rpm, 900 rpm, and 1,050 rpm were tested to evaluate the banana fiber extraction rate. The results showed that the machine functioned reliably across all three modes, with extraction rates of 10.1%, 11.2%, and 10.8% achieved at motor speeds of 750, 900, and 1050 rpm, respectively. Therefore, this banana fiber extraction machine can be used to extract banana fibers and meet the requirements of producing handicraft materials in Vietnam.

Temporal and Spatial Evolution Characteristics and Its Driving Mechanism of Land Use/Cover in Vietnam from 2000 to 2020

Research on the spatial distribution and dynamic evolution of land use/land cover (LULC) is the basis for land management and ecological protection. However, there is currently a lack of long-term analysis on the evolution of LULC on the national scale in Vietnam. Based on the GLC_FCS30 dataset, this paper analyzed the temporal and spatial evolution of LULC in Vietnam from 2000 to 2020 as well as its driving mechanism using methods such as dynamicity, flow direction diagrams, principal component analysis, and multivariate stepwise regression. The results show that: (1) cropland, forest, and shrubland are Vietnam’s most important land-cover types. In 2020, the above three types of land area accounted for 34.77%, 32.36%, and 26.13% of the total land area, respectively. (2) From 2000 to 2020, the area of cropland and forest areas continued to shrink (−5.64%, −3.96%); the area of shrubland, water bodies, and other land areas expanded (+4.87%, +12.29%, +15.04%); and the area of impervious surfaces expansion was the most significant (+100.40%). (3) The integrated dynamic degree of LULC in Vietnam shows a spatial differentiation of high in the south, followed by the north, and lowest in the center. In the early period (2000–2010), the LULC rate of change in each region was rapid, while it gradually decreased in the later period (2010–2020). The most important LULC changes in Vietnam can be divided into two parts: (a) the mutual conversion of forest, cropland, and shrubland and (b) one-way conversion of cropland to impervious surfaces. (4) LULC changes in Vietnam are mainly affected by economic development and human activities, especially the GDP, population, and urbanization rate. There is no reliable statistical relationship between LULC and climatic factors. The results of this study contribute to the analysis of LULC processes in similar regions, and will also help the Vietnamese government strengthen national land management and planning in a targeted manner.

Adaptation and validation of the Van Rie tuberculosis stigma scale in Vietnam

ObjectivesTuberculosis (TB) stigma contributes to diagnostic delay, disease concealment, and reduced wellbeing for affected individuals. Despite the availability of several TB stigma scales, most high-TB burden countries do not have a culturally validated version available. This study evaluated the Van Rie TB stigma scale (VTSS) among people with TB in Vietnam. MethodsThis study consisted of two phases. In phase 1, the VTSS was culturally and linguistically adapted to the Vietnamese context. In phase 2, people with TB were invited to complete a survey containing the VTSS, a depression scale, and a quality of life scale. The data analysis included confirmatory factor analysis (CFA), exploratory factor analysis (EFA), construct validity, and floor or ceiling effects. ResultsIn phase 1, items were reworded from the third person to the first person. The TB/HIV co-infection items (items 7 and 11) were the least relevant for people with TB (62% and 73% relevance, respectively). In phase 2, the CFA demonstrated adequate goodness-of-fit indices (GFI = 0.88, CFI = 0.96, RMSEA = 0.058); however several of the item factor loadings were low. The EFA demonstrated good internal consistency (α = 0.85) and revealed one dominant factor. Construct validity was low. ConclusionsThe VTSS demonstrated good psychometric properties in Vietnam. Depending on the purpose of the scale, the HIV co-infection items and item 10 could be considered for removal.

Factors affecting talent management in Vietnam

The purpose of this research is to evaluate factors affecting talent management in Vietnam. Through building the theoretical basis and literature review, the author chooses 4 typical factors: Talent strategy; Motivation to work; Work environment; Corporate culture to assess the impact on talent management. The strength of that research is to use the SPSS model in conjunction with AMOS, and at the same time carry out surveys on the largest scales of Vietnam to accurately assess the model compared to other research. The study used survey data of 570 samples, collected from 27 enterprises with the largest scale in Vietnam. Research results show that there is a difference between the influences of selected factors on talent management in Vietnam. From the results of this study, a system of scales to evaluate talent for the business was re-tested, and at the same time showed the relationship between latent variables in the model as well as between latent variables and variables observe. Since then, the author gives recommendations to improve the efficiency of talent management in Vietnam. These recommendations include awareness of talent management, appropriate remuneration, strategies, recognition and support for talent at work, satisfaction, confidence in the leadership.

Performance of a process-based model for predicting robusta coffee yield at the regional scale in Vietnam

Reliable and timely prediction of robusta coffee (Coffea canephora Pierre ex A. Froehner) yield is pivotal to the profitability of the coffee industry worldwide. In this study we assess the performance of a simple process-based model for simulating and predicting robusta coffee yield at the regional scale in Vietnam. The model includes the key processes of coffee growth and development and simulates its response to variation in climate and potential water requirements throughout the growing season. The model was built and evaluated for the major Vietnamese robusta coffee-producing provinces Dak Lak, Dak Nong, Gia Lai, Kon Tum, and Lam Dong, using official provincial coffee yield data and climate station data for the 2001–2014 period, and field data collected during a 10-year (2008–2017) survey. Overall, good agreements were found between the observed and predicted coffee yields. Root mean square error (RMSE) and mean absolute percentage error (MAPE) values ranged from 0.24 to 0.33 t ha−1, and 9% to 14%, respectively. Willmott's index of agreement (WI) was greater than or equal to 0.710 in model evaluation steps for three out of five provinces. The relatively low values of WI were found for provinces with relatively low inter-annual yield variability (i.e. Dak Lak and Dak Nong). Moreover, the model was successfully tested using remote sensing satellite and model-based gridded climate data: MAPE values were ≤ 12% and RMSE were ≤ 0.29 t ha−1. Such evaluation is important for long-term coffee productivity studies in these regions where long-term climate stations data are not readily available. The simple process-based model presented in this study could serve as a basis for developing an integrated seasonal climate-robusta coffee yield forecasting system, which would offer substantial benefits to coffee growers and industry through better supply chain management and preparedness for extreme climate events, and increased profitability.

Renewable energy from biomass surplus resource: potential of power generation from rice straw in Vietnam

Biomass, one of the renewable resources, is expected to play an important role in the world’s energy future. In Asia, rice straw is an abundant agricultural surplus because rice is one of the leading staple food crops in the region. Often, rice straw is burned directly in the field via uncontrolled combustion methods that emit large amounts of short-lived air pollutants, greenhouse gases, and other pollutants. In Vietnam, the energy and environment protection sectors are facing great challenges because of rapid urbanisation and industrialisation. A national strategic choice is to exploit renewable energy, including biomass-derived energy, to achieve energy security and CO2 emission reduction. This study investigates the potential of rice straw as an energy source for power plants at a local scale in Vietnam using data derived from satellite Sentinel-1 images. The results show that Vietnam can produce 2,565 MW from rice straw, for which 24 out of 63 provinces have a potential capacity higher than 30 MW, and the Kien Giang province has the highest capacity (245 MW). The study also analyses limitations and obstacles overcoming which can promote the biomass energy sector in the country.

KIỂM ĐỊNH VÀ ĐÁNH GIÁ THANG ĐO THÁI ĐỘ ĐỊNH HƯỚNG KHỞI NGHIỆP TẠI VIỆT NAM

In light of Entrepreneurship literate, the Entrepreneurial Attitude Orientation (EAO) scale is a multidimensional self-report measure of attitudes toward entrepreneurship. There are little studies have tested the validity and reliability of the EAO scale in different social and cultural situations. This research’s purpose is to examine the generalizability of the EAO scale in Vietnam context by applying two step of the preliminary research and the main research. In the former, we applied both of the qualitative and quantitative method with the finding of four dimensions scale and 20 items were removed. The latter used the Cronbach alpha for testing the scale’s reliability and EFA method for examining the scale’s validity. The result shows that EAO scale in Vietnam are include five dimension instead of four, with the appearance of the new one, namely ACHPC. Furthermore, 26 of the original 75 items were removed due to unsatisfactory loading. The findings generally support the generalizability of the four-dimensional model of the EAO and contribute the specialize scale in Vietnam context.

COMPARISON THE PNED SCORE WITH THE GB, AIMS65 SCORES FOR RISK STRATIFICATION IN PATIENTS WITH UPPER GASTROINTESTINAL BLEEDING

Back ground: Upper gastrointestinal bleeding (UGIB) is a common cause of internal medical or surgical emergencies and often make the life-threatening risks to patients. The stratification of risk in triage the patients with UGIB is very critical for clinicians. PNED score is still a fairly new scale in Vietnam and currently no research that evaluated and compared it with the GB and AIMS65 scores in risk stratification of UGIB patients has been found. This study were aimed to (i) evaluate the accuracy, predictive value of the GB, AIMS65 and PNED scores and (ii) to compare the PNED score with the GB and AIMS65 scores in risk stratification of patients with upper gastrointestinal bleeding on admission to the Department of Gastroenterology at Cho Ray Hospital. Subjects and Research Methods: A prospective cohort study investigating all patients presenting with UGIB on admission and treatment at the Department of Gastroenterology in Cho Ray Hospital from March 15th, 2019 to August 30th, 2019. We calculated PNED, GB, AIM65 scores and compared the area under the ROC curve (AUC) to determine the predicted value of the scores. Results: One hundred and seventy-five patients were included. Median age of 59.51 ± 14.36, male/female ratio of 2.07/1, proportion of patients requiring blood transfusion intervention: 45.1%, hemostatic endoscopy: 30.3%, surgery: 0.57%, re-bleeding during hospitalization: 9.7%, overall mortality: 5.1%. About predicting required blood transfusion intervention of GB score was highest then PNED score and finally AIMS65 score with AUC respectively 67.1%; 63.1%; 56.4% (p<0.001). About predicting endoscopic intervention of PNED score was highest then GB score and finally AIMS65 score with AUC respectively 62.2%; 55.1%; 52.7%. About predicting required medical intervention of PNED score was highest then GB score and finally AIMS65 score with AUC respectively 69.7%; 66.2%; 56.3%. About predicting required re-bleeding of PNED score was highest then GB score score with AUC respectively 80.8%; 62.1%. AUC of AIMS65 score of 48.5% has no value in predicting re-bleeding. About predicting the risk of mortality of AIMS65 score was highest then GB score score and finally PNED score with AUC respectively 77.3%; 73.5%; 61.3%. The PNED score with a cut-off ≥ 6, has a positive predictive value is high for the overall medical intervention (76.81%) compared with GB score (68.33%) has cut-off ≥ 9 and AIMS65 score (61.33%) has cut-off ≥ 2. Conclusion: The PNED score is superior to the GB and AIMS65 scores in predicting hemostatic interventions, general medical interventions and re-bleeding. Key words: Upper gastrointestinal bleeding, PNED score, GB score, AIM65 score

Hiết kế, tổng hợp và đánh giá khả năng ức chế enzyme histone deacetylase (HDAC) in silico của một số dẫn xuất tương tự belinostat

Belinostat is a histone deacetylase inhibitor for the treatment of hematological malignancies and solid tumor. In this study, belinostat analogues were successfully synthesized through a simple and effective process suited to laboratory scale in Vietnam including 6 steps: i) Preparation of m-nitrobenzaldehyde using KNO3/H2SO4; ii) Use of Wittig reaction with ylide compound as the nucleophile; iii) Reduction of –NO2 group. iv) Preparation of sulfonyl; v) Substitution reaction with amines as the nucleophile; and vi) Synthesis of hydroxamate by NH2OH. Belinostat derivatives were obtained in good yields. The structures of the products were confirmed by 1H-NMR and MS spectra. The evaluation of HDAC inhibitory capacity of the synthesized compounds in silico was also carried out to investigate the biological activity.

Socio-Cultural Impacts of Professional Football Clubs on Local Residents: Developing and Validation of Measurement Scale in Vietnam

Socio-Cultural Impacts of Professional Football Clubs on Local Residents: Developing and Validation of Measurement Scale in Vietnam

An Analysis of the Efficiency of Local Government Expenditure and the Minimum Efficient Scale in Vietnam

The purposes of this study were to; (i) estimate the efficiency of local government expenditure by province and city in Vietnam, (ii) test if there was a change in the efficiency of local government expenditure with the rapid development of Vietnam, and (iii) estimate the size of the population that is improving local government expenditures. By using the stochastic frontier cost function method to estimate the cost inefficiency, we found that Vietnam has been improving the efficiency of local government expenditure while achieving rapid economic growth from FY2005 to FY2009. In addition, we simulated a minimum efficient scale (MES) to determine the size of the province population that is improving local government expenditures. We found that the MES in Vietnam is 1,394,859.

A Study on the Breaking and Winnowing Machine for Cocoa Beans at Small Industrial Scale in Vietnam

In the chocolate or cocoa powder processing process, the roasted cocoa beans have to pass to the breaking and winnowing step to obtain the nibs. The quality of chocolate or cocoa powder depends strongly on the amount of shell that is not separated and still mixing on the nibs. Recently, most of the cocoa bean breaking machines are based on the principle of grinding. This leads to some disadvantages as (1) the shells might be not separated from the cocoa kernel after the shattering that results in low efficiency of the cleaning process (<96%); and (2) the nibs are also crushed so much to become smaller so that they are easy to moving out together with the shell in the winnowing step due to the similar density. As a result, the ratio of nibs loss during the cleaning process is very high as around 11.3%. Therefore, the shattering and cleaning process has strongly affected the economic efficiency of cocoa production. One of the new methods for cocoa breaking and winnowing in order to increase the cleanness level and to reduce the nibs loss rate has been developed and studied. The cocoa seeds breaking based on the centrifugal mechanism in combination with the pneumatic cleaning have been conducted to manufacturing breaking and winnowing machine with a capacity of about 80 kg/hour. The experimental results indicate that the efficiency of the cleaning process rises to more than 99% and the ratio of nibs loss reduces to 1.6% only which leads to increase the economic efficiency of the cocoa processing process.

Application and validation of a consumer ethnocentrism scale in a young Vietnamese market segment

The primary objective of this study is to validate a consumer ethnocentrism scale in Vietnam on the basis of the existing scale, CETSCALE, proposed by Shimp and Sharma. The results from a student population show that the revised scale consists of two elements: affective and behavioral. The multidimensional structure of the revised scale is supported in the exploratory factor analysis phase and confirmed in the confirmatory factor analysis phase. The findings also indicate that convergent validity, discriminant validity, and nomological validity of the revised scale are established. The paper starts with a literature review of consumer ethnocentrism, includes methodology and discussions, and concludes with theoretical and managerial implications.

Researcher intersubjectivity: a methodology for jointly building an interactive electronic early childhood quality involvement/rating scale

ABSTRACTResearching quality in early childhood settings has been operationalized in many ways, within and across countries. Nevertheless, despite some consensus on what might constitute a universally recognized view of what is considered essential for young children’s development, there are strong indicators that locally developed assessment tools are likely to give more contextually relevant results. Yet, little appears to be known about how to develop localized tools for assessing quality, especially in culturally diverse research contexts. Further, it would seem that not much is understood about the ways researchers and research participants have worked together to achieve reciprocal outcomes. In drawing upon cultural-historical theory, this paper goes beyond the traditional binary of an emic–etic perspective and instead describes a dialectical model for creating conditions for generating research intersubjectivity. An example of how researchers and participants worked together to develop an interactive e-quality rating scale in Vietnam is presented with the research exchange methods of Dialogue through the technology, Capturing moments of localized quality, Community walk, and Research selfies. These methods together acted to underpin the methodology that foregrounds what we have termed research intersubjectivity.

Methods for Designing Signalized Double-Intersections with Mixed Traffic in Vietnam

In the current Vietnamese urban, there are existences of two close at-grade intersections, which are defined as double-intersections. Traffic congestion at these intersections occurs frequently, especially in rush hours. The most considered concern is the short distance between two junctions, which makes the confliction to the mixed flow in this space. This paper presents two methods for designing signalized double-intersections and their application for a case study of Lang - Lang Ha - Le Van Luong - Nguyen Ngoc Vu double-intersections. Based on acceptable results, the methods can be potentially implemented for double-intersection design in the large scale in Vietnam, especially, in the places where modern software is not used widely for designing intersections.

Determining the arsenic, cadmium, lead, copper and chromium contents by atomic absorption spectrometry in Pangasius fillets from Vietnam.

Pangasius is a fish produced on a large scale in Vietnam and exported to many countries. Since river contamination from human activities can affect the safety of this food, fish consumption can cause exposure to potentially toxic elements for humans. The aim of this study, therefore, was to assess arsenic, cadmium, lead, copper and chromium contents by atomic absorption spectrometry in Pangasius fillet produced in the provinces of Dong Thap and Can Tho (Vietnam) and exported to Brazil. The limits of detection were: arsenic 0.5443 µg kg(-1) , cadmium 0.0040 mg kg(-1) , chromium 0.0004 mg kg(-1) , copper 0.0037 mg kg(-1) and lead 0.0284 mg kg(-1) . Analysis of 20 samples showed results below the limit of detection for arsenic, chromium and lead, while copper average concentration was 0.0234 mg kg(-1) . Cadmium average concentration was 0.0547 mg kg(-1) , with no significant difference between the two regions studied. The samples of Pangasius had no detectable concentrations of arsenic, chromium, copper and lead, and do not represent a hazard to public health. However, cadmium analysis revealed non-compliant samples, demonstrating the importance of monitoring the quality of imported Pangasius fish. © 2015 Society of Chemical Industry.