Advanced Magnetic Materials Produced by Using Rapid Quenching Technology

Nguyen Hoang Nghi,Nguyen Van Dung,Trinh Thi Thanh Nga,Bui Thi Khanh Nhung,Mai Thanh Tung,Nguyen Huu Tinh,Hoang Nhat Hieu,Bui Xuan Chien,Nguyen Thi Hong Tam 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.6

Amorphous alloys produced by using a rapid quenching technique are considered to be a precursor for producing nanosized and multiphase structures by precipitation (the top-down method). By using this technique, several new magnetic materials with different magnetic properties based on different physical mechanisms have been manufactured and investigated. Three new magnetic materials, a nanocrystalline soft magnetic material, a soft-hard permanent magnet and a Me-3d granular alloy with a GMR effect, what were prepared under local conditions, are presented and discussed in the experimental point of view. Amorphous alloys produced by using a rapid quenching technique are considered to be a precursor for producing nanosized and multiphase structures by precipitation (the top-down method). By using this technique, several new magnetic materials with different magnetic properties based on different physical mechanisms have been manufactured and investigated. Three new magnetic materials, a nanocrystalline soft magnetic material, a soft-hard permanent magnet and a Me-3d granular alloy with a GMR effect, what were prepared under local conditions, are presented and discussed in the experimental point of view.

A Robust Adaptive Direct Controller for Non-Linear First Order Systems

Thi-Hong-Thanh Nauyen,Xuan-Tinh CU,Thi-Minh-Huong NGUYEN,Thi-Hoan HA,Dac-Hai NGUYEN,Van-Truong TRAN 제어로봇시스템학회 2005 제어로봇시스템학회 국제학술대회 논문집 Vol.2005 No.6

Large Magnetocaloric Effect above 300 K and Magnetoresistance in (La0.5Pr0.5)1-xPbxMnO3 Perovskites

Nguyen Chau,Duong Thi Hanh,Bui Cong Tinh,Nguyen Hoang Luong,Nguyen Duc Tho,Nguyen Hoang Hai 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

Perovskite compounds (La0.5Pr0.5)₁- xPbxMnO₃ (x = 0.1 - 0.5) with orthorhombic structure were prepared by using a solid-state reaction technique. In the studied samples, the spin-glass-like state occurs at low temperatures and the Curie temperature, Tc, increases from 170 K (x = 0.1) to 336 K (x = 0.5) because of a strong double exchange. The magnetic entropy change, │△Sm│, reached its largest value of 2.06 J/kg·K at △H = 13.5 kOe for the sample with x = 0.4 (Tc = 323 K). Due to the large │△Sm│ and high Tc, these materials are suggested for use as active magnetic refrigerants for magnetic refrigeration technology at temperatures above room temperature. While the conductivity of the samples with x = 0.1 and 0.2 exhibits only a semiconducting behavior over the whole measured temperature range, there is insulator-metallic phase transition on the R(T) curves of the samples with x = 0.3 - 0.5. The magnetoresistance of the samples was measured and large values for MR were found. Perovskite compounds (La0.5Pr0.5)₁- xPbxMnO₃ (x = 0.1 - 0.5) with orthorhombic structure were prepared by using a solid-state reaction technique. In the studied samples, the spin-glass-like state occurs at low temperatures and the Curie temperature, Tc, increases from 170 K (x = 0.1) to 336 K (x = 0.5) because of a strong double exchange. The magnetic entropy change, │△Sm│, reached its largest value of 2.06 J/kg·K at △H = 13.5 kOe for the sample with x = 0.4 (Tc = 323 K). Due to the large │△Sm│ and high Tc, these materials are suggested for use as active magnetic refrigerants for magnetic refrigeration technology at temperatures above room temperature. While the conductivity of the samples with x = 0.1 and 0.2 exhibits only a semiconducting behavior over the whole measured temperature range, there is insulator-metallic phase transition on the R(T) curves of the samples with x = 0.3 - 0.5. The magnetoresistance of the samples was measured and large values for MR were found.

Impact of long COVID-19 on posttraumatic stress disorder as modified by health literacy: an observational study in Vietnam

Han Thi Vo,Tien Duc Dao,Tuyen Van Duong,Tan Thanh Nguyen,Binh Nhu Do,Tinh Xuan Do,Khue Minh Pham,Vinh Hai Vu,Linh Van Pham,Lien Thi Hong Nguyen,Lan Thi Huong Le,Hoang Cong Nguyen,Nga Hoang Dang,Trung 질병관리청 2024 Osong Public Health and Research Persptectives Vol.15 No.1

Objectives: The incidence of posttraumatic stress disorder (PTSD) has increased, particularly among individuals who have recovered from coronavirus disease 2019 (COVID-19) infection. Health literacy is considered a “social vaccine” that helps people respond effectively to the pandemic. We aimed to investigate the association between long COVID-19 and PTSD, and to examine the modifying role of health literacy in this association.Methods: A cross-sectional study was conducted at 18 hospitals and health centers in Vietnam from December 2021 to October 2022. We recruited 4,463 individuals who had recovered from COVID-19 infection for at least 4 weeks. Participants provided information about their sociodemographics, clinical parameters, health-related behaviors, health literacy (using the 12-item short-form health literacy scale), long COVID-19 symptoms and PTSD (Impact Event Scale-Revised score of 33 or higher). Logistic regression models were used to examine associations and interactions.Results: Out of the study sample, 55.9% had long COVID-19 symptoms, and 49.6% had PTSD. Individuals with long COVID-19 symptoms had a higher likelihood of PTSD (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.63–2.12; p<0.001). Higher health literacy was associated with a lower likelihood of PTSD (OR, 0.98; 95% CI, 0.97–0.99; p=0.001). Compared to those with long COVID-19 symptoms and the lowest health literacy score, those with long COVID-19 symptoms and a 1-point health literacy increment had a 3% lower likelihood of PTSD (OR, 0.97; 95% CI, 0.96–0.99; p=0.001).Conclusion: Health literacy was found to be a protective factor against PTSD and modified the negative impact of long COVID-19 symptoms on PTSD.

Pleural Effusion Diagnosis using Local Interpretable Model-agnostic Explanations and Convolutional Neural Network

Hai Thanh Nguyen,Cham Ngoc Thi Nguyen,Thao Minh Nguyen Phan,Tinh Cong Dao 대한전자공학회 2021 IEIE Transactions on Smart Processing & Computing Vol.10 No.2

The application of Artificial Intelligence (AI) in medicine has been a leading concern worldwide. Artificial intelligence-based systems not only support storing a large amount of data but also assist doctors in making a diagnosis. In addition, deep learning has obtained numerous achievements that greatly supported the development of image-based diagnostic methods. On the other hand, deep learning models still work as a black box that makes interpreting the output a challenge. Diagnosis based on images is currently a trend that plays a key role in clinical treatment by discovering abnormal regions for disease diagnosis. This paper proposes a computer-aid diagnosis system to support a pleural effusion diagnosis based on Chest X-ray (CXR) images. This study investigated several shallow convolutional neural network architectures that classify CXR images as well as the technique for processing imbalanced data using oversampling technology. The best model in the experiments was chosen to generate explanations using the Local Interpretable Model-agnostic Explanations (LIME) to support providing signals for pleural effusion diagnosis. The proposed method is expected to provide more informative CXR images of the pleural effusion diagnosis process.

Impacts of Corporate Social Responsibility and Green Marketing Strategy on Business Performance: The Moderating Role of Balanced Scorecard

NGUYEN, It Van,QUACH, Trinh To,NGUYEN, Tinh Thi Korea Distribution Science Association 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.10

On the underpinning theory of the Resource Based Theory, this research examines the impact of corporate social responsibility and green marketing strategy on business performance with the moderating role balanced scorecard. Corporate social responsibility concentrates on related to government, the environment, customers, and employees. Green marketing strategy concentrates on approaches in terms of green products, green prices, green places, and green promotion. Business performance is measured by groups of indicators financial, and non-financial. The moderating role balanced the scorecard at the financial, customer, process, learning, and growth level. Research results with survey data from 419 managers at different food enterprises in Ho Chi Minh City processed through the structural analysis method, showed that corporate social responsibility has the strongest positive impact on business performance, followed by the green marketing strategy as the second strong positive impact on the business performance and results also showed that the balanced scorecard moderating role increases the level of the strong positive impact of the above relationship. Besides, it also showed the difference in the demographic control variables. Based on the findings, some implications are drawn to help the managers of enterprises improve the moderating role balanced scorecard when implementing corporate social responsibility and green marketing strategies thereby contributing to increasing business performance.

Magnetic Properties of the Frustrated Magnet Cu5(PO4)3(OH)4 on a Peculiar Spin Network Composed of Pentagons and Triangles

Hikomitsu Kikuchi,Nguyen Thi Tinh Y,Yutaka Fujii,Akira Matsuo,Koichi Kindo 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12

Orthorombic Cu5(PO4)3(OH)4 (pseudomalachite) is a layered compound. Each Cu-O layer in thiscompound is separated by PO4 tetrahedra. The spin network in the bc-plane of a pseudomlachite iscomposed of triangles and pentagons, which will induce the spin frustration effect. This network maybe a new type of geometrically frustrated spin lattice. Magnetic susceptibility, specific heat, highfield magnetization measurements are used to study the magnetic properties of Cu5(PO4)3(OH)4 innatural mineral samples. Magnetic ordering is observed at around 4.2 K. The spin entropy changeat the transition temperature is about one-fifth times smaller than that expected for a usual longrangeorder. A 1/5 magnetization plateau is observed in the high-field magnetization curve. Theplateau is explained based on a simple model in which the spin network is assumed to be composedof chain, dimer and monomer units.

Mental Health Among Healthcare Workers During the COVID-19 Pandemic in Vietnam

Nhan Phuc Thanh Nguyen,Ha Phan Ai Nguyen,Cao Khoa Dang,Minh Tri Phan,Huynh Ho Ngoc Quynh,Van Tuan Le,Chinh Van Dang,Tinh Huu Ho,Van Trong Phan,Van Trong Phan,Thang Phan,Dang Thi Anh Thu 대한예방의학회 2024 예방의학회지 Vol.57 No.1

Objectives: The objective of this study was to characterize mental health issues among Vietnamese healthcare workers (HCWs) and to identify related factors.Methods: A cross-sectional study was conducted with 990 HCWs in 2021. Their mental health status was measured using the Depression, Anxiety, and Stress Scale.Results: In total, 49.9%, 52.3%, and 29.8% of respondents were found to have depression, anxiety, and stress, respectively. The multivariable linear regression model revealed that factors associated with increased anxiety scores included depression scores (β, 0.45; 95% confidence interval [CI], 0.39 to 0.51) and stress scores (β, 0.46; 95% CI, 0.41 to 0.52). Factors associated with increased depression scores included being frontline HCWs (β, 0.57; 95% CI, 0.10 to 1.10), stress scores (β, 0.50; 95% CI, 0.45 to 0.56), and anxiety scores (β, 0.41; 95% CI, 0.36 to 0.47), while working experience was associated with reduced depression scores (β, -0.08; 95% CI, -0.16 to -0.01). Factors associated with increased stress scores included working experience (β, 0.08; 95% CI, 0.00 to 0.16), personal protective equipment interference with daily activities (β, 0.55; 95% CI, 0.07 to 1.00), depression scores (β, 0.54; 95% CI, 0.48 to 0.59), and anxiety scores (β, 0.45; 95% CI, 0.39 to 0.50), while age was associated with reduced stress scores (β, -0.12; 95% CI, -0.20 to -0.05).Conclusions: Specific interventions are necessary to enhance and promote the mental health of HCWs so they can successfully cope with the circumstances of the pandemic.