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Binh Thang Tran,Nguyen Minh Tu,Minh Tam Nguyen,Thanh Gia Nguyen,Vo Nu Hong Duc,Thi Tra My Tran 질병관리본부 2023 Osong Public Health and Research Persptectives Vol.14 No.4
Objectives: We assessed the prevalence of stress, anxiety, and depression among adolescents living in families with separated or divorced parents in Hue City, Vietnam and identified factors associated with these conditions.Methods: This cross-sectional study enrolled 309 adolescents, aged 12 to 17 years, living in families with separated or divorced parents in Hue City, Vietnam. The depression anxiety stress scale-21 (DASS-21) was used to measure stress, anxiety, and depression. Predictors of overall and individual mental health problems were identified using ordered and binary logistic regression, respectively.Results: The DASS-21 scale revealed a 49.2% prevalence of stress, while anxiety and depression had s prevalence rates of 61.5%. Among participants, 42.4% experienced all 3 mental health issues. Several factors were identified as significant predictors of mental health problems, including poor to average economic status (adjusted odds ratio [aOR], 2.00; 95% confidence interval [CI], 1.21–3.31; p=0.007); being in high school (aOR, 5.02; 95% CI, 2.93–8.60; p<0.001); maternal occupation of teacher, healthcare professional, or official (aOR, 2.39; 95% CI, 1.13–5.03; p=0.022); longer duration of family separation or divorce (aOR, 1.24; 95% CI, 1.05–1.45; p=0.009); living with one’s mother (aOR, 1.69; 95% CI, 1.03–2.76; p=0.04); alcohol consumption (aOR, 1.70; 95% CI, 0.99–2.92; p=0.050); and being bullied (aOR, 5.33; 95% CI, 1.10–25.69; p=0.037). Most of these factors were associated with stress, anxiety, and depression. Additionally, smoking was associated with stress.Conclusion: Adolescents with separated or divorced parents were at increased risk of stress, anxiety, and depression. The findings of this study provide important implications for prevention programs.
Nhung Thanh Thi Truong,Tam Huu Nguyen,Bao Kim Doan,Le-Thu T. Nguyen,Tam Hoang Luu,Chau Duc Tran,Thiet Quoc Nguyen,Ha Tran Nguyen 한국고분자학회 2021 Macromolecular Research Vol.29 No.11
In this research, three organic photocatalysts, 4-(4H-dithieno[3,2-b:2',3'- d]pyrrol-4-yl)-N,N-diphenylaniline, 4-(pyren-1-yl)-4H-dithieno[3,2-b:2',3'-d]pyrrole and 4-(6b,10-dihydroperylen-3-yl)-4H-dithieno[3,2-b:2',3'-d]pyrrole have been successfully synthesized through C-N coupling reactions. The chemical structures and the optical properties of the obtained organic photocatalysts have been characterized via 1H NMR,13C NMR, elemental analysis, and UV-Vis spectroscopy. Next, these dithieno[3,2-b:2′,3′-d]pyrrole-based photocatalysts have been used for the polymerization of methyl methacrylate, 2-(dimethylamino)ethyl methacrylate and tert-butyl methacrylate monomers under 365 nm UV irradiation, resulting in (meth)acrylate polymers with controlled molecular weights and low polydispersity indexes.
Tu Anh Do,Mang Tia,Thuan Huu Nguyen,Tuyet Thi Hoang,Tam Duc Tran 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.1
Three-dimensional finite element (FE) thermal and stress models were created to compute the temperature evolution, thermal stress and potential of cracking in a segmental concrete box girder segment during construction. User-defined subroutines were developed in the ANSYS program to activate the degree of hydration-dependent heat rate and material properties, and creep behavior in the thermal and stress calculations. The developed FE model was verified with experimental measurements of a concrete cube. Adiabatic temperature rise, together with compressive strength and splitting tensile strength for a high-strength concrete mix typically used in construction of box girders were tested and incorporated in the subroutines. The effect of casting time and placement season (summer and winter), initial concrete temperature change, and insulation on the risk of cracking in a cast-in-situ box girder segment at early ages was investigated using the proposed model. The results indicate that the temperature difference between the segment’s middle and the gate corner is very large leading to a high cracking risk. Use of an insulation material such as blankets along with casting concrete at the nighttime would significantly lessen the thermal tensile stress and thus could reduce cracking risk in the segment.
Long Nguyen-Ngoc,Tu Anh Do,Viet Hai Hoang,Tuyet Thi Hoang,Tam Duc Tran 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.6
Engineering infrastructure includes a large number of concrete structures. The main binder used in concrete is Portland cement, which reacts with water when mixing. During the chemical reaction (cement hydration) heat is released causing non-uniform temperature distribution and subsequent internal stresses that may crack the concrete. Therefore, accurate prediction of concrete temperature evolution in design and control of concrete temperature in construction are crucial tasks for engineers. This paper presents the development of a finite difference (FD) model for predicting thermal behavior of concrete structures during cement hydration. A formwork or insulation layer that covers the outer of the concrete was accounted for in the model. The temperature profiles calculated by the proposed model show close agreement with those measured from a concrete bridge footing and a concrete cube. The Particle Swarm Optimization (PSO) algorithm was adopted to compute an “equivalent convection coefficient” for the convection boundary condition in the simplified model for several common insulation materials. The results show that using the simplified model along with an equivalent convection coefficient can give a significant reduction in the computation time while the accuracy is still maintained. In addition, an equation for estimating an equivalent convection coefficient for a given insulation material was developed for design and practical purposes. The proposed method can be used in the design of concrete structures and control of concrete temperature to prevent early-age thermal cracking thus ensuring the expected durability and service life. From the obtained results, varying equivalent convection values are also recommended to be used for different insulation materials.