Effect of Saline Concentrations on Biological Nitrification in Batch Reactor

Young Joon Lee, Nguyen Viet Hoang, Nguyen Hong Khanh, Pham Tuan Linh, Gi Youn Kim 조선대학교 기초과학연구원 2011 조선자연과학논문집 Vol.4 No.2

Pham Tuan Linh2 and Gi Youn Kim This study was carried out on 4 batch reactors to determine the specific ammonium oxidizing rate (SAOR), specific nitrate forming rate (SNFR) and inhibitory degree of nitrifying activities with saline concentrations. Under salt free condition ammonia was consumed during the reaction period within 200 min. When the salt level increased to 10, 20 and 30 g NaClL-1 in reactor, ammonia depletion took 250, 300 and above 350 min, respectively. During concentration above 10 g NaClL-1, there was nitrite accumulation. Also, at 30 g NaClL-1 ammonia did not depleted and NO2 --N accumulated until the final reaction. Nitrate formation rates decreased with increasing salt concentration. SAOR and SNFR showed a decreasing trend as salinity concentrations were increased. The SAOR was reduced from 0.2 to 0.08 mg NH4+-N g-1VSS day-1 as the salt concentration increased from 0 to 30 g NaCLL-1. Similarly, the SNFR decreased from 0.26 kg NO3--N kg-1VSS day-1 at saline free to 0.1 kg NO3--N kg-1VSS day-1 at saline 30 g L-1. A severe inhibition of nitrifiers activity was observed at increased salt concentrations. The inhibition ratio of specific ammonium oxidation rates were 17, 47 and 60% on the reactor of 10, 20 and 30 g NaClL-1 added, respectively. The inhibition ratio of specific nitrate forming rates also were inhibited 30, 53 and 62% on the reactor of 10, 20 and 30 g NaClL-1 added, respectively. As the salinity concentrations increased from 0 to 30 mg NaClL-1, the average MLSS concentration increased from 1,245 to 1,735 mgL-1. The SS concentration of supernatant in reactor which settled about 30 minutes was not severely difference between concentration of salt free reactor and one of those high salt contained reactors

Factors Affecting Job Pursuit Intention in Hotel Industry in Ho Chi Minh, Viet Nam

Linh Viet HOANG,Hieu Minh VU,Vu Minh NGO 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

Given the rise in international tourism and the rapid growth of the Vietnamese economy, the hospitality industry in Ho Chi Minh City, Vietnam’s commercial hub, has been facing severe labor shortages due to competition with other fast-growing parts of the economy. These struggles to acquire high-quality employees is strangling future growth and placing new importance on the role of recruitment. To better understand the effectiveness of an organization’s recruitment strategy, recruiters need to ascertain the Job Pursuit Intention (JPI) of job seekers to efficiently align an applicant’s work notions with the organization’s goals. This study aims to investigate the factors impacting on JPI among employees working in the hotel sector in Ho Chi Minh City. Secondary data are from previous studies and primary data are from consultation with 10 experts, group discussions and five in-depths structured interviews with 15 random employees and 302 survey questionnaires with employees working in three five-star hotels. Cronbach’s Alpha, EFA, T-Test, ANOVA are used for statistical analysis. The findings show that compensation, career advancement, and work-life balance affect JPI of job seekers, in which compensation is the most influential factor. Furthermore, recommendations for recruiters, further research and limitations of this study have been laid out.

Corporate Social Responsibility and Job Pursuit Intention of Employees in Vietnam

HOANG, Linh Viet,VU, Hieu Minh,NGO, Vu Minh Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

As the Industrial Revolution 4.0 is spreading its wings all over the world and, therefore, also in Vietnam, the logistics industry in Vietnam is facing a severe shortage of human resources in both quantitative and qualitative terms. The role of human resources management (HRM) becomes extremely important. Recruitment is considered the first major function of HRM practices and is the cornerstone of successful in business. In order to improve the recruitment strategy, recruiters need to better understand job pursuit intentions (JPI) of job seekers. Therefore, this study investigates how four dimensions of corporate social responsibility (CSR) affect JPI among employees working in the logistics sector in Vietnam. The secondary data are from previous studies and published newspaper articles. Meanwhile, the primary data are collected from consultation with 10 experts and through five in-depth structured interviews with 30 randomly-selected employees as well as 288 survey questionnaires returned from employees in the logistics companies in Vietnam. The findings show that economic citizenship, legal citizenship and ethical citizenship are positively related to JPI of job seekers, where economic citizenship appears to be the most influential factor. The limitations of the study and an agenda for further research are put forward.

Understanding the COVID-19 Infodemic: Analyzing User-Generated Online Information During a COVID-19 Outbreak in Vietnam

Ha-Linh Quach,Thai Quang Pham,Ngoc-Anh Hoang,Dinh Cong Phung,Viet-Cuong Nguyen,Son Hong Le,Thanh Cong Le,Dang Hai Le,Anh Duc Dang,Duong Nhu Tran,Nghia Duy Ngu,Florian Vogt,Cong-Khanh Nguyen 대한의료정보학회 2022 Healthcare Informatics Research Vol.28 No.4

Objectives: Online misinformation has reached unprecedented levels during the coronavirus disease 2019 (COVID-19) pandemic. This study analyzed the magnitude and sentiment dynamics of misinformation and unverified information about public health interventions during a COVID-19 outbreak in Da Nang, Vietnam, between July and September 2020. Methods: We analyzed user-generated online information about five public health interventions during the Da Nang outbreak. We compared the volume, source, sentiment polarity, and engagements of online posts before, during, and after the outbreak using negative binomial and logistic regression, and assessed the content validity of the 500 most influential posts. Results: Most of the 54,528 online posts included were generated during the outbreak (n = 46,035; 84.42%) and by online newspapers (n = 32,034; 58.75%). Among the 500 most influential posts, 316 (63.20%) contained genuine information, 10 (2.00%) contained misinformation, 152 (30.40%) were non-factual opinions, and 22 (4.40%) contained unverifiable information. All misinformation posts were made during the outbreak, mostly on social media, and were predominantly negative. Higher levels of engagement were observed for information that was unverifiable (incidence relative risk [IRR] = 2.83; 95% confidence interval [CI], 1.33–0.62), posted during the outbreak (before: IRR = 0.15; 95% CI, 0.07–0.35; after: IRR = 0.46; 95% CI, 0.34-0.63), and with negative sentiment (IRR = 1.84; 95% CI, 1.23–2.75). Negatively toned posts were more likely to be misinformation (odds ratio [OR] = 9.59; 95% CI, 1.20–76.70) or unverified (OR = 5.03; 95% CI, 1.66–15.24). Conclusions: Misinformation and unverified information during the outbreak showed clustering, with social media being particularly affected. This indepth assessment demonstrates the value of analyzing online “infodemics” to inform public health responses.

Magnetocaloric Effect in La_0.7Ca_0.25Ba_0.05MnO₃ Nanocrystals Exhibiting the Crossover of First- and Second-Order Magnetic Phase Transformation

Thanh, Tran Dang,Linh, Dinh Chi,Van, Hoang Thanh,Ho, Thi Anh,Van Manh, Tien,Bau, Le Viet,Phan, The-Long,Yu, Seng-Cho The Japan Institute of Metals 2015 MATERIALS TRANSACTIONS Vol.56 No.9

Effect of Saline Concentrations on Biological Nitrification in Batch Reactor

Young Joon Lee,Nguyen Viet Hoang,Nguyen Hong Khanh,Pham Tuan Linh,Gi Youn Kim 조선대학교 기초과학연구원 2011 조선자연과학논문집 Vol.4 No.2

External Factors Influencing Bid/No-Bid Decision for Supervision Consultant Service: A Case of Construction Project in Hanoi

HA, Son Tung,TRAN, Manh Linh,HOANG, Huy Viet,TRAN, Van Hung Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.6

This paper investigates the potential impact of external factors on bid/no-bid decision for supervision consultant service on construction project in Hanoi, the capital of Vietnam. The data used in this study are secondary data taken from annual reports and sourced from the Department of Public Procurement, Ministry of Planning and Investment in Hanoi. Besides, to identify the impact of external factors on bid/no-bid decision for supervision consultant service on construction project in Hanoi, the study collected data from 272 qualified questionnaires from bidders doing business in Hanoi. Cronbach's Alpha, EFA and regression model are used to explore the impact of each independent variable on bid/no-bid decision for supervision consultant service on construction project. The results show that three external determinants, including Project characteristic (PC), Legal codes (LC) and Competition (C) are affecting bid/no-bid decision for supervision consultant service on construction project in Hanoi. Among them, Project characteristic (PC) and Legal codes (LC) have positive relationships with bid/no-bid decision for supervision consultant service on construction project, whereas Competition (C) negatively affects bid/no-bid decision for supervision consultant service on construction project. It means the more contractors actually participate in a bid, the less bid/ no-bid decisions are made.

The Determinants of Listed Commercial Banks’ Profitability in Vietnam

Hai Thanh PHAN,Tien Ngoc HOANG,Linh Viet DINH,Dat Ngoc HOANG 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

The study investigates the factors affecting the profitability of listed commercial banks in Vietnam. Survey data for this research were collected from 10 Vietnamese listed commercial banks for the period from 2008 to 2018. In the study, we have built a model of econometric regression with the dependent variable being listed commercial banks’ profitability results measured through ROA. The research methods used include descriptive statistics, IV regression and OLS regression analysis, and the authors carried out the model verification with Stata 14 software. The results showed that operating efficiency, loans size, retail loans ratio, state ownership, inflation rate, and GDP growth are factors that have a positive impact on profitability On the other hand, variables such as capital size, credit risk, liquidity risk, bank size, and revenue diversification are statistically insignificant; hence, these variables are not statistically adequate to indicate the influence of those independent variables to banks’ profitability. The findings of this study suggest that the quality of assets should be considered in the context that bad debt risks come from lending heavily to the real estate sector. Meeting Basel II’s capital compliance requirements is relatively difficult for small listed commercial banks compared to bigger listed commercial banks in Vietnam.

A Novel Injectable pH–Temperature Sensitive Hydrogel Containing Chitosan–Insulin Electrosprayed Nanosphere Composite for an Insulin Delivery System in Type I Diabetes Treatment

Thuy An Trinh,Thai Minh Duy Le,Hoang Gia Vinh Ho,Thi Cam Thach To,Vu Viet Linh Nguyen,Dai Phu Huynh,Doo Sung Lee 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Faculty of Materials Technology, Ho Chi Minh University of Technology (HCMUT)/Vietnam National University Ho Chi Minh City; ¹School of Chemical Engineering and Theragnostic Macromolecules Research Center, Sungkyunkwan University; ²Vietnam National University Ho Chi Minh City/National Key Laboratory of Polymer and Composite Materials, Ho Chi Minh University of Technology, Vietnam National University; ³Faculty of Materials Technology, Ho Chi Minh University of Technology (HCMUT)/ Vietnam National University Ho Chi Minh City/Research Center for Polymeric Materials, Ho Chi Minh University of Technology, Vietnam National University In this research, a novel insulin composite delivery system was prepared and characterized. Insulin drug was loading in chitoshan nanospheres using electrospraying method, a pH- and temperature-sensitive biodegradable hydrogel, which is an oligomer serine-poly(lactide)-poly(ethylene glycol)-poly (lactide)-oligomer serine (OS-PLA-PEG-PLA-OS) pentablock copolymer was used as a matrix to containing chitosan–insulin electro sprayed nanospheres (CIN). The properties of the OS-PLA-PEG-PLA-OS pentablock copolymer and the chitosan–insulin nanoparticles such as sol-gel transition, degradation in vitro and in vivo were characterized. The results showed that the chitosan–insulin nanospheres uniformly distributed in the matrix had a reinforcing effect on the mechanical properties and prolonged the degradation time of the hydrogel depot under body conditions. In addition, the cytotoxicity experiment results indicate that the composite could be used as a biomaterial for drug delivery system. The composite solutions accommodating different concentrations of the chitosan–insulin nanospheres were subcutaneously injected into induced diabetic BALB/c mice to study the in vivo insulin-release profile. The result showed that insulin concentrations in blood plasma were maintained at a steady-state level. Furthermore, the bio-properties of the insulin were retained and it showed a blood glucose level reducing effect for more than 60 hours after injection to a streptozotocin (STZ)-induced diabetic mouse model. The results suggested that this injectable pH–temperature sensitive hydrogel containing chitosan– insulin electro sprayed nanosphere composites has promising potential applications for type 1 diabetes treatment.