Effect of adding non-ferromagnetic nanoparticles to grain boundary on coercivity of sintered Nd-Fe-B magnet

Pham Thi Thanh,Nguyen Van Duong,Nguyen Hai Yen,Nguyen Huy Ngoc,Nguyen Mau Lam,Kieu Xuan Hau,유성조,Nguyen Huy Dan 한국물리학회 2018 Current Applied Physics Vol.18 No.3

In this work, we investigated the influence of additional compounds of Nd-Cu-Al, Dy-Nb-Al, Dy-Zr-Al and Nb-Cu-Al on coercivity of sintered Nd-Fe-B magnets. The additional nanoparticles with size in the range of 40e80 nmwas mixed with the micrometer Nd-Fe-B powder before sintering process. The results show that the coercivity of the sintered Nd-Fe-B magnets can be improved by introducing additional nanoparticles to their grain boundaries. The improvement of the coercivity of the magnets is clearly dependent on composition and fraction of the additional compounds. While the Dy-Nb-Al, Dy-Zr-Al and Nb-Cu-Al compounds degrade the coercivity of the sintered Nd-Fe-B magnets, the Nd-Cu-Al nanoparticles considerably improve this quantity. The coercivity the sintered Nd16.5Fe77B6.5 magnets has been enhanced about 40% by adding 3 wt% of the Dy-free compound of Nd40Cu30Al30.

Effect of adding non-ferromagnetic nanoparticles to grain boundary on coercivity of sintered Nd-Fe-B magnet

Thanh, Pham Thi,Van Duong, Nguyen,Yen, Nguyen Hai,Ngoc, Nguyen Huy,Lam, Nguyen Mau,Hau, Kieu Xuan,Yu, Seong Cho,Dan, Nguyen Huy ELSEVIER 2018 CURRENT APPLIED PHYSICS Vol.18 No.3

<P>In this work, we investigated the influence of additional compounds of Nd-Cu-Al, Dy-Nb-Al, Dy-Zr-Al and Nb-Cu-Al on coercivity of sintered Nd-Fe-B magnets. The additional nanoparticles with size in the range of 40-80 nm was mixed with the micrometer Nd-Fe-B powder before sintering process. The results show that the coercivity of the sintered Nd-Fe-B magnets can be improved by introducing additional nanoparticles to their grain boundaries. The improvement of the coercivity of the magnets is clearly dependent on composition and fraction of the additional compounds. While the Dy-Nb-Al, Dy-Zr-Al and Nb-Cu-Al compounds degrade the coercivity of the sintered Nd-Fe-B magnets, the Nd-Cu-Al nanoparticles considerably improve this quantity. The coercivity the sintered Nd16.5Fe77B6.5 magnets has been enhanced about 40% by adding 3 wt% of the Dy-free compound of Nd40Cu30Al30. (C) 2017 Elsevier B.V. All rights reserved.</P>

Toward Post-Pandemic Sustainable FDI Workforce: An Examination of Factors Affecting the Well-Being of Migrant Workers in Ho Chi Minh City

( Pham Thanh Thoi ),( Tran Dinh Lam ),( Nguyen Hong Truc ) 부산외국어대학교 아세안연구원 2024 Suvannabhumi Vol.16 No.1

Globalization and the flow of foreign direct investment (FDI) in the post-pandemic context continue to play a critical role in shaping the workforce of emerging countries. In Vietnam, evidence obtained during the pandemic revealed that the well-being of employees, especially migrant workers, was extremely poor due to both work and non-work factors. This paper examines the most significant factors that impact the well-being of workers employed by various FDI companies in two Vietnamese industrial parks. The survey evidence (n=200) shows that worker well-being is influenced by seven key factors categorized in three dimensions, namely material stressors, social stressors, and human stressors. A further qualitative analysis of 60 participants provides an understanding of the ways in which each factor affects workers’ well-being and how elements of well-being in the Vietnamese context are different compared with other countries. Low salaries, lack of social support, work-life imbalance due to job demands, and the interplay between these three determinants significantly affect the overall well-being of workers. In the current business climate, it is important to have well-targeted policies that encourage high-tech investments as well as persuade domestic firms to address low salaries and economic migration. To manage valuable human resources and keep competitive advantages, foreign firms need to authentically implement corporate social responsibility (CSR) initiatives focusing on workers’ benefits, especially providing workforce housing. This will bring about win-win outcomes of improved employee well-being and business sustainability.

Non-achievement of the Low-Density Lipoprotein Cholesterol Goal in Older Patients with Type 2 Diabetes Mellitus and a Very High Cardiovascular Disease Risk: A Multicenter Study in Vietnam

Huan Thanh Nguyen,Khang Pham Trong Ha,An Huu Nguyen,Thu Thanh Nguyen,Hang My Lam 대한노인병학회 2021 Annals of geriatric medicine and research Vol.25 No.4

Background: Lowering the low-density lipoprotein cholesterol (LDL-c) level is important for reducing cardiovascular (CV) events. However, little is known about the management of LDL-c in older patients with type 2 diabetes mellitus (T2DM). This study investigated the prevalence and factors associated with the non-achievement of LDL-c goals in older T2DM patients with a very high risk of CV diseases. Methods: This multicenter cross-sectional study measured the LDL-c levels of 733 T2DM outpatients from December 2019 to July 2020. The patients were aged ≥60 years, had very high risks of CV disease, and had been on LDL-c-lowering therapy for 6 months or more. The goal of lipid concentrations were assessed based on the recent guidelines of the European Society of Cardiology. We applied logistic regression analysis to identify the factors associated with the non-achievement of the LDL-c goal. Results: The mean age of the patients was 68.6±7.2 years. In total, 654 patients (89.2%) did not achieve the aggressive LDL-c goal of <1.4 mmol/L. In the adjusted model, the factors associated with the non-achievement of the LDL-c goal were obesity defined by body mass index (odds ratio [OR]=2.33; 95% confidence interval [CI], 1.13–4.81; p=0.022) and high-intensity statin therapy (OR=0.03; 95% CI, 0.01–0.05; p<0.001), while age, sex, education level, smoking habit, and comorbidities were not associated. Conclusion: Older patients with T2DM who are at a very high CV disease risk are often unable to achieve their LDL-c goal. Obesity can increase the probability of not achieving the LDL-c goal, whereas high-intensity statin therapy can decrease this probability.

Knowledge and Attitude Towards Tobacco Smoking among 13-15 Year-Old School Children in Viet Nam - Findings from GYTS 2014

Nguyen, Thanh Huong,Nguyen, Trung Kien,Kim, Bao Giang,Hoang, Van Minh,Phan, Thi Hai,Doan, Thu Huyen,Luong, Ngoc Khue,Nguyen, Thuy Linh,Nguyen, Tuan Lam,Pham, Thi Quynh Nga Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup1

Studies have shown that smoking is a learnt behavior, often initiated during adolescence. This paper aims to describe tobacco-related knowledge, attitude and associations among school adolescents aged 13-15 with exposure to anti-smoking information. Using data from the Global Youth Tobacco Survey (GYTS) in Viet Nam, 2014, knowledge was measured through 4 questions about tobacco use, and attitude was assessed through 3 questions on personal, social and environmental aspects. Students giving most anti-tobacco responses to all questions were considered as having correct knowledge or appropriate attitude or both. Access to anti-smoking information was determined by exposure to any media messages on tobacco control during the past 30 days and teaching in school about the danger of tobacco use during the past 12 months. A substantial percentage of students thought that being near others who smoke might be harmful to them and smoking is harmful to health (89.4% and 89.6% respectively). However, only 46.4% reported that it is definitely difficult to quit smoking and 66.9% thought that smoking for only 1 or 2 years, once stopped, is harmful to health. Slightly more than half of the respondents reported appropriate attitude that young smokers have fewer friends than others and smoking makes them less attractive and less comfortable at social events. Noticing anti-smoking messages in the media together with having lessons in school about the dangers of tobacco substantially increased the likelihood of having correct knowledge, appropriate attitude and both. Despite relatively high awareness about smoking harms, effective educational communication is still highly needed to improve the level of comprehensive knowledge and an appropriate attitude regarding tobacco use.

The Effect of Non-Audit Services on Auditor Independence: Evidence from Vietnam

DOAN, Nga Thanh,PHAM, Cuong Duc,NGUYEN, Thuong Thi Uyen,VU, Mai Phuong,PHAM, Lam Ha Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12

Independence is a factor which has a significant impact on auditing quality, especially in the recent times where the marketplace is increasingly demanding transparency. The independence of auditors is assessed based on the main criteria such as the reliability of the audit opinions, the accuracy, truthfulness of financial reports, and the objectivity in the opinions of the auditor. The study investigates the effects of non-audit services (NAS) on auditor independence in emerging economies such as Vietnam. Non-audit services include taxation services, management advisory services and outsourcing internal audit services. Based on previously relevant researches, the authors develop hypotheses and a regression model about non-audit services (independent variables) and audit independence (dependent variable). The research collects data by 5-scale Likert questionnaire. The findings indicate the relationship between NAS and auditor independence. Specifically, the results reveal two main factors that have influence on auditor independence, namely, taxation services and management advisory services. The results of our research can be considered as new findings and can be compared to previous researches in Vietnam, which establishes a new viewpoint about the relationship between the NAS and the independence of the auditor. This result can be implemented for countries or jurisdictions which are similar to Vietnam.

Macro-Economic Factors Affecting the Vietnam Stock Price Index: An Application of the ARDL Model

Hoang Tuan DAO,Le Hang VU,Thanh Lam PHAM,Kim Trang NGUYEN 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.5

Using the ARDL approach, this study examined the impact of macro factors on Vietnam’s stock market in the short and long run from 2010 to 2021. The State Bank of Vietnam and the International Monetary Fund provided time series data for this study. Research results show that in the long run, money supply and exchange rate respectively affect the stock market. The money supply had a positive effect on the VN-Index, while the exchange rate showed the opposite effect. However, the study did not find a relationship between world oil price and interest rates on VN-Index in the long run. On the other hand, in the short term, there are relationships between variables; specifically, interest rates and exchange rates have a negative impact on the VN-Index, while the world oil price and the fluctuation of money supply M2 of the previous one and two months showed an impact in the same direction on this index. The differences in the regression results on the impact of exchange rate and oil price on the VN-Index compared to previous studies come from the characteristics of Vietnam’s stock market, with the large capitalization of companies in the oil and gas sector, and the structure of Vietnam’s economy with export heavily depends on FDI sector.

A Taguchi approach with electron-beam irradiation to optimize the efficiency of removing enrofloxacin from aqueous media

Hong Thi Bich Truong,Hiep Nghia Bui,Hieu Trung Nguyen,Thanh-Luu Pham,Duy Ngoc Nguyen,Yuan-Shing Perng,Linh Thi My Lam,Thi-Dieu-Hien Vo,Van-Truc Nguyen,Ha Manh Bui 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.4

Electron-beam (EB) irradiation was employed to degrade enrofloxacin (ENR) in an aqueous solution. Thealgal growth inhibition test revealed that ENR exhibited low toxicity against the cyanobacterium Arthrospira sp., with anEC50-96 h value of 5.17mg/L. The Taguchi design also involved finding the best optimum for ENR treatment using EB. Results revealed that the high-efficiency removal of ENR in an aqueous solution was approximately 98.53% under theoptimum conditions of an absorbed dose of 5 kGy, a pH of 5.0, and an initial ENR concentration of 10 mg/L and anH2O2 concentration of 2mM. The ERR degradation under a couple of EB irradiation and H2O2 followed pseudo-firstorderkinetics, with an R2 of ~0.970. The major degradation pathways of ENR were suggested by density functional theory,natural bond orbital calculations, and liquid chromatography-tandem mass spectrometry (LC/MS/MS) analysis. Lifecycle assessment (LCA) was also performed to evaluate the impact of the EB on removing ENR; the industrial processwas designed based on laboratory tests aimed with the ReCiPe tool. The obtained results indicated that energy consumptionand H2O2 affect environmental impacts with order human health, ecology systems, and natural resource. The LCAalso proved that EB could be a green and efficient method for eliminating pharmaceutical contaminants in water.

Cigarette Smoking among Adolescents aged 13-15 in Viet Nam and Correlates of Current Cigarette Smoking: Results from GYTS 2014 Data

Le, Thi Huong,Nga, Thi Thu Vu,Nguyen, Ngoc Dung,Le, Thi Thanh Xuan,Kim, Bao Giang,Phan, Thi Hai,Doan, Thu Huyen,Luong, Ngoc Khue,Nguyen, Tuan Lam,Hoang, Van Minh,Pham, Thi Quynh Nga Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup1

The aim of this paper is to report the rate of current and ever cigarette smoking and explore correlates of current cigarette smoking among adolescents aged 13-15 in Viet Nam. This analysis was derived from GYTS survey, which comprised of 3,430 adolescents aged 13-15, conducted in 2014 in 13 cities and provinces of Viet Nam. We calculated the weighted rates of current and ever cigarette smoking and reported patterns of smoking behavior. We also performed logistic regression to explore correlates of current cigarette smoking behavior. The weighted rate of ever cigarette smoking was 9.5% (95% confidence interval (CI): 8.5 %-10.5%), in which the weighted rate among males (15.4%; 95% CI: 13.6%-17.0%) was higher than that among females (4.2%; 95% CI: 3.3%-5.1%). The weighted rate of current cigarette smoking was relatively low at 2.5% (95%CI: 2.0%-3.0%) with higher weighted rate among males (4.9%; 95% CI: 3.8%-5.9%) compared to the corresponding figure among females (0.2%; 95% CI: 0.0 %-0.5%). Current cigarette smoking was significantly higher among males than females, in students aged 15 versus 13 years old, and in students who had several or all close friends smoking and students with daily observation of smoking at school. For greater smoking reduction outcomes, we recommend that tobacco interventions for adolescents should consider targeting more male students at older ages, establish stricter adherence to school-based banning of cigarette smoking, engage both smoking and nonsmoking adolescents and empower adolescents to resist peer smoking influence as well as changing their norms or beliefs towards smoking benefits.

Perceived Risk of Sharing Other People’s Information on Facebook: The Perspective of Young People in Ho Chi Minh City, Vietnam

Dinh Tien Minh,Tran Ngoc Thuy,Ngo Nguyen Gia Nghi,Nguyen Yen Vy,Nguyen Thi Thanh Lam,Pham Cong Minh KINFORMS 2021 Management Review Vol.16 No.2

In Vietnam, young people are gradually becoming the most accessible objects to social networks. With the development of technology, they usually use online social networks (ONS) as a tool to update information through multimedia content, which may contain other people s information. In different cases, other people s information will be shared and received for different purposes. Therefore, the risk is inevitable and may affect the privacy of individuals whose information is shared, causing turbulence in the community. This study aims to measure impact and find out the factors that influence the willingness of others to share information on social networks in Ho Chi Minh City by examining young people s perceptions that their activities on Facebook may be risky for other people s information. Besides that, the study proposes solutions to avoid possible risks when sharing information with others.