The Determinants of Environmental Information Disclosure in Vietnam Listed Companies

NGUYEN, Thi Le Hang,NGUYEN, Thi Thu Hien,NGUYEN, Thi Thanh Huyen,LE, Thi Hong Anh,NGUYEN, Van Cong Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.2

Environmental pollution and climate change in Vietnam are now becoming a major concern. This situation is increasing the pressure on the companies to improve their social responsibility in production and business activities and disclose the environmental information to meet the requirements of stakeholders. This study investigates the internal and external factors of the company that affects the environmental information disclosure of listed companies on the Vietnam stock market as business sector, firm size, corporate manager perceptions, profitability, financial leverage, community pressure, pressures from stakeholders, government pressure influencing environmental information disclosure. Analytical data collected through the survey of 120 listed companies on the Ho Chi Minh City Stock Exchange (HOSE). By testing Cronbach's Alpha, exploratory factor analysis (EFA) and logistic regression analysis, the results of the study show that the level of environmental information disclosure of listed companies on the stock market in Vietnam depends heavily on government regulations, followed by the pressure from stakeholders, community pressure, views of business managers, companies size, business sector, and particularly profitability and financial leverage factors that have a negative relationship with environmental information disclosure.

A facile thermal evaporation route for large-area synthesis of tin oxide nanowires: Characterizations and their use for liquid petroleum gas sensor

Nguyen Van Hieu,Le Thi Ngoc Loan,Nguyen Duc Khoang,Nguyen Tuan Minh,Do Thanh Viet,Do Cong Minh,Tran Trung,Nguyen Duc Chien 한국물리학회 2010 Current Applied Physics Vol.10 No.2

In this paper, a very simple procedure was presented for the reproducible synthesis of large-area SnO2nanowires (NWs) on a silicon substrate by evaporating Sn powders at temperatures of 700, 750, and 800 ℃. As-obtained SnO2 NWs were characterized by field emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. They revealed that the morphology of the NWs is affected by growth temperature and the SnO2 NWs are single-crystalline tetragonal. The band gap of the NWs is in the range of 4.2–4.3 eV as determined from UV/visible absorption. The NWs show stable photoluminescence with an emission peak centered at around 620 nm at room-temperature. The sensors fabricated from the SnO2 NWs synthesized at 700 ℃ exhibited good response to LPG (liquefied petroleum gas) at an operating temperature of 400 ℃.

The Impact of International Integration on the Inequality of Income between Rural and Urban Areas in Vietnam

NGUYEN, Thi Thanh Huyen,NGUYEN, Thi Thu Hien,NGUYEN, Thi Le Hang,NGUYEN, Van Cong Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.3

The study examines the impact of international integration on Vietnam's rural and urban income inequalities using the regression model. The data used for this study is based on the results of the Vietnam Household Living Standards survey from 2008 to 2016 of the General Statistics Office. These surveys conducted nationwide with a sample size of 46,995 households in 3,133 communes/wards which were representative at national, regional, urban, rural and provincial levels. The level of international economic integration used in the study is the proportion of import and export turnover of GDP, the proportion of FDI and GDP by province. Due to the heterogeneity and unobservableness of the single observant in the data set, we selected the models of random and fixed effects. The research results show that during the economic integration process, the Export/GDP factor is negatively related to income inequality. The remaining factors (GDP per capita, FDI/GDP, Educational level of households, Percentage of internet users, Aggregation of foreign cash inflow and GDP of the province) are all positively related to income inequality. The findings help assess the impact of international integration on rural-urban income inequality, but also provides a concrete basis to help policymakers address income inequality in the integration process.

The effective model of the human Acetyl-CoA Carboxylase inhibition by aromatic-structure inhibitors

Nguyen Truong Cong Minh,Bui Tho Thanh,Le Xuan Truong,Nguyen Thi Bang Suong,Le Thi Xuan Thao 한국전기전자학회 2017 전기전자학회논문지 Vol.21 No.3

The research investigates the inhibition of fatty acid biosynthesis of the human Acetyl-CoA Carboxylase enzyme by the aromatic-structure inhibitors (also known as ligands) containing variables of substituents, contributing an important role in the treatment of fatty-acid metabolic syndrome expressed by the group of cardiovascular risk factors increasing the incidence of coronary heart disease and type-2 diabetes. The effective interoperability between ligand and enzyme is characterized by a 50% concentration of enzyme inhibitor (IC50) which was determined by experiment, and the factor of geometry structure of the ligands which are modeled by quantum mechanical methods using HyperChem 8.0.10 and Gaussian 09W softwares, combining with the calculation of quantum chemical and chemico-physical structural parameters using HyperChem 8.0.10 and Padel Descriptor 2.21 softwares. The result data are processed with the combination of classical statistical methods and modern bioinformatics methods using the statistical softwares of Department of Pharmaceutical Technology – Jadavpur University – India and R v3.3.1 software in order to accomplish a model of the quantitative structure - activity relationship between aromatic-structure ligands inhibiting fatty acid biosynthesis of the human Acetyl-CoA Carboxylase.

Aluminum in rocks: Optimized microwave-assisted acid digestion and UV-Vis spectrophotometric measurement

Nguyen Thanh-Nho,Thai Huynh-Thuc,Le-Thi Anh-Dao,Do Minh-Huy,Le-Thi Huynh-Mai,Le Quang-Huy,Nguyen-Thi Kim-Sinh,Nguyen Cong-Hau 한국분석과학회 2023 분석과학 Vol.36 No.5

Aluminium (Al) is one of the major elements in rocks and its concentration can be varied, depending on different rock types as well as sources. The present study aimed to propose an analytical method based on the UV-Vis as a cheap, simple, and common instrument equipped in most laboratories for Al quantification in rocks after the microwave assisted acid digestion. The aluminone and 8-hydroxyquinoline were investigated for the colorimetric assay. The results show that the 8-hydroxyquinoline reagent was more favorable in terms of the minimized affects of the potential interferences present in the digested solutions, i.e., Fe3+, Si4+ and F–. The calibration curve was constructed from 0.10 mg/L to 3.00 mg/L with the goodness of linearity (R2 = 0.9996). The limits of detection and quantification (LOD and LOQ) were estimated, i.e., 0.029 mg/L and 0.087 mg/L, respectively. The 8-hydroxyquinoline was applied to real rock samples, demonstrating favorable precision (RSD = 0.34 %-1.8 %) and no remarkable differences were found compared to the inductively coupled plasma-mass spectrometry (ICP-MS) as a reference measurement approach.

Correlations between abnormalities of morphological details and DNA fragmentation in human sperm

Nguyen, Hiep Tuyet Thi,Dang, Hong Nhan Thi,Nguyen, Thai Thanh Thi,Nguyen, Trung Van,Dang, Thuan Cong,Nguyen, Quoc Huy Vu,Le, Minh Tam The Korean Society for Reproductive Medicine 2022 Clinical and Experimental Reproductive Medicine Vol.49 No.1

Objective: As the associations of sperm DNA fragmentation with morphology have not been examined in detail, this study aimed to investigate the relationship between abnormalities of morphological details and DNA integrity in human sperm. Methods: In this cross-sectional study, men from infertile couples were enrolled at Hue Center for Reproductive Endocrinology and Infertility, Vietnam. Conventional semen parameters, including morphological details, were analyzed following the World Health Organization 2010 criteria. Sperm DNA fragmentation was evaluated using a sperm chromatin dispersion assay. The relationships and correlations between semen parameters, sperm morphology, and the type of halosperm and the DNA fragmentation index (DFI) were analyzed. Results: Among 130 men in infertile couples, statistically significant differences were not found in the sperm halo type between the normal and abnormal sperm morphology groups. The percentage of round-head spermatozoa was higher in the DFI >15% group (16.98%±12.50%) than in the DFI ≤15% group (13.13% ±8.82%), higher values for amorphous heads were found in the DFI >15% group, and lower values for tapered heads were observed in the DFI ≤15% group; however, these differences were not statistically significant. Small-halo sperm and the DFI were positively correlated with round-head sperm (r=0.243, p=0.005 and r=0.197, p=0.025, respectively). Conclusion: The rate of general sperm morphological abnormalities in semen analysis was not related to sperm DNA integrity. However, round sperm heads were closely associated with sperm DNA fragmentation.

Physical and Numerical Model of Flow through the Spillways with a Breast Wall

Nguyen Cong Thanh,Wang Ling-Ling 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.7

Spillways with breast walls are often used in such situations as increasing the regulating storage of flood discharge or disposing sediment from the reservoirs, etc. The hydraulic characteristics of the spillways with breast walls can be obtained by experimental, analytical and numerical methods. The aim of this study is to predict some characteristics of flow through the spillway with a breast wall with low and average-head operation using the numerical modeling along with some turbulence closure models. The experimental data were used to validate the numerical predictions. The results show that the RNG k-ε and the standard k-ε turbulence models can predict quite precisely some characteristics, such as the water surface, the discharge, and the vertical pressure distribution in comparison with the measured data. However, some errors occur on this pressure in the region nearby the crest boundary. Furthermore, the RNG k-ε turbulence model performed more accurately than the standard k-ε model as compared to the experimental data. Therefore, the RNG k-ε turbulence model uses to properly validate the characteristics of the flow through spillway with a breast wall under various conditions, without recourse to expensive experimental procedures.

A Routing Method Considering Physical Impairments in Multi-Fiber WDM Network for Future Multimedia Services

Nguyen Thanh Cong,Yusuke Hirota,Hideki Tode,Koso Murakami 한국멀티미디어학회 2009 한국멀티미디어학회 국제학술대회 Vol.2009 No.-

Optical WDM networks have been studied as future promising networks for high quality multimedia services like forthcoming 8K super high definition video applications. In extremely higher data rate transmission systems like 160Gbps ones, physical impairments degrade optical signal more seriously. We especially pay attention to Polarization Mode Dispersion (PMD) which is the typical physical impairment. In this paper, we propose a new routing method for multi-fiber WDM networks that reduces influence of physical impairments and makes loss probability improve. Its performance is evaluated by computer simulations.

Predictive Tile Selection for 360-Degree VR Video Streaming in Bandwidth-Limited Networks

Nguyen, Thanh Cong,Yun, Ji-Hoon IEEE 2018 IEEE communications letters Vol.22 No.9

<P>To stream 360-degree video bandwidth-efficiently to virtual reality users, only a subset of a video’s spatial tiles corresponding to the current viewport of a user can be transferred, but tile selection is challenging since a user’s viewport keeps moving over time. In this letter, we find that the error distribution of fixation point prediction is formally derived as a normal distribution. Based on this theoretical finding, the region where a user’s future viewport is likely to reside with a given confidence level is obtained in a closed form and the proposed algorithm selects tiles covering the region.</P>

Study on different graphite finned latent heat storages for solar application

Nguyen Thanh Phuong,Cong Le Van,Nhan Nguyen Thi,박찬우 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

Graphite is a promising material in application of thermal storage system, due to its high thermal conductivity and extreme lightweight. In this current investigation, an experimental research on graphite finned latent heat storage is tested. The effect of fin shape, solar irradiation, heat transfer fluid (HTF) flow rate has been considered to evaluate the thermal performance of charging process of phase change material (PCM). The total thermal resistance, heat transfer rate and liquid fraction are the main parameter to analyze.