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Preparation of amino-functionalized silica for copper removal from an aqueous solution
Dang Viet Quang,Jong Kil Kim,Pradip B. Sarawade,Dang Huu Tuan,김희택 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1
In the present research, amino-functionalized silica materials were synthesized to develop absorbents for removing copper (II) ions from water. Three kinds of silica with various BET surface areas and pore volumes (331.4 m2/g, 460.1 m2/g, 717.7 m2/g and 1.38 cm3/g, 1.06 cm3/g, 0.57 cm3/g, respectively) were used to determine an optimum material. 3-Aminopropyltrimethoxysilane (3-APTMS) and N-[3-(trimethoxysilyl)propyl]-ethylenediamine (MSDA) are two amino-functional moieties grafted onto silica surfaces. A maximum copper absorption of 33.45 mg/g was confirmed using the aminofunctionalized material at an initial 3-APTMS concentration of 2.52 mmol/g. Silica with a BET surface of 331 m2/g and a pore volume of 1.38 cm3/g demonstrated a good copper absorption capacity. Interference species such as pH, NH3 and EDTA were also studied in this work.
Nguyen Duc Anh,Pham Van Thanh,Doan Tu Lap,Nguyen Tuan Khai,Tran Van An,Tran Duc Tan,Nguyen Huu An,Dang Nhu Dinh 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.2
Forest fires inflict great losses of human lives and serious damages to ecological systems. Hence, numerous fire detection methods have been proposed, one of which is fire detection based on sensors. However, these methods reveal several limitations when applied in large spaces like forests such as high cost, high level of false alarm, limited battery capacity, and other problems. In this research, we propose a novel forest fire detection method based on image processing and correlation coefficient. Firstly, two fire detection conditions are applied in RGB color space to distinguish between fire pixels and the background. Secondly, the image is converted from RGB to YCbCr color space with two fire detection conditions being applied in this color space. Finally, the correlation coefficient is used to distinguish between fires and objects with fire-like colors. Our proposed algorithm is tested and evaluated on eleven fire and non-fire videos collected from the internet and achieves up to 95.87% and 97.89% of F-score and accuracy respectively in performance evaluation.
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.
Thang Phan,Ha Phan Ai Nguyen,Cao Khoa Dang,Minh Tri Phan,Vu Thanh Nguyen,Van Tuan Le,Binh Thang Tran,Chinh Van Dang,Tinh Huu Ho,Minh Tu Nguyen,Thang Van Dinh,Van Trong Phan,Binh Thai Dang,Huynh Ho Ngo The Korean Society for Preventive Medicine 2023 예방의학회지 Vol.56 No.4
Objectives: The coronavirus disease 2019 (COVID-19) pandemic has increased the workload of healthcare workers (HCWs), impacting their health. This study aimed to assess sleep quality using the Pittsburgh Sleep Quality Index (PSQI) and identify factors associated with poor sleep among HCWs in Vietnam during the COVID-19 pandemic. Methods: In this cross-sectional study, 1000 frontline HCWs were recruited from various healthcare facilities in Vietnam between October 2021 and November 2021. Data were collected using a 3-part self-administered questionnaire, which covered demographics, sleep quality, and factors related to poor sleep. Poor sleep quality was defined as a total PSQI score of 5 or higher. Results: Participants' mean age was 33.20±6.81 years (range, 20.0-61.0), and 63.0% were women. The median work experience was 8.54±6.30 years. Approximately 6.3% had chronic comorbidities, such as hypertension and diabetes mellitus. About 59.5% were directly responsible for patient care and treatment, while 7.1% worked in tracing and sampling. A total of 73.8% reported poor sleep quality. Multivariate logistic regression revealed significant associations between poor sleep quality and the presence of chronic comorbidities (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.17 to 5.24), being a frontline HCW directly involved in patient care and treatment (OR, 1.59; 95% CI, 1.16 to 2.16), increased working hours (OR, 1.84; 95% CI,1.37 to 2.48), and a higher frequency of encountering critically ill and dying patients (OR, 1.42; 95% CI, 1.03 to 1.95). Conclusions: The high prevalence of poor sleep among HCWs in Vietnam during the COVID-19 pandemic was similar to that in other countries. Working conditions should be adjusted to improve sleep quality among this population.