TEACHERS’ CORRECTIVE FEEDBACK ON ENGLISH STUDENTS’ WRITING

This investigates the participants’ attitudes towards corrective feedback as well as the types of corrective feedback on learners’ performance by questionnaires for both students and teachers. Fifty–eight 2nd-year students and 5 teachers of English at a university in the Mekong Delta of Vietnam participated in the study. The results indicated that students had a positive attitude towards teachers’ corrective feedback. Besides, with the analyzed data, correction with comments and teacher correction was considered as the most useful strategy when giving feedback in the learners’ performance. The outcomes of the study suggest a widespread employment of corrective feedback in teaching writing at universities and colleges in the region.   Article visualizations

EFL teachers’ perceptions of professional development activities and their effects in a non-anglosphere context

Providing teachers with adequate professional development (PD) is a central tenet to enhance education quality. In Vietnam, despite the blossoming of PD activities promoted over the past decade, the central question of how effectively these existing activities facilitate changes in teachers’ practice has been under-researched. This mixed-method study responded to the scarcity in understanding the effectiveness of PD activities in the Vietnamese setting by employing a questionnaire administered to 80 high school teachers and six semi-structured interviews. Evidence from the questionnaire and interviews revealed that EFL teachers participated in PD activities on an occasional basis. Institution-internal or in-house professional activities were most common, while joining a professional affiliation such as a TESOL association was the rarest. Also, PD activities have positively reinforced the teachers’ language proficiency, teaching practice, and planning practical lessons to meet students’ learning needs. The discussions and recommendations are made for enhancing the quality of PD activities

Factors influencing well-being of special education teachers in Ho Chi Minh City, Vietnam

Increasing numbers of special education teachers are leaving jobs across different cultures and countries, which leads to teachers’ well-being has gotten more attention over the past decades. This study aims to investigate the levels of well-being and explore the factors influencing well-being in special education teachers in Vietnam. Special education teachers (N = 81) from three special education schools and a special education Centre in Vietnam were involved in the current study. Descriptive analysis, Pearson correlation, and multiple linear regression were used to examine the levels of well-being and determine whether life satisfaction, job satisfaction, self-compassion, and salary and benefits influencing the well-being levels among teachers. The results show a positive correlation between well-being and job satisfaction, life satisfaction, self-compassion, and salary and benefits. Additionally, multiple regression analysis reveals that life satisfaction, self-compassion, and salary and benefits influence well-being levels positively, meaning that teachers with increased life satisfaction, self-compassion, and salary and benefits have higher levels of well-being. The present findings contribute to the general discussion about the nature of well-being and the influential factors in teachers’ well-being. It is highly suggested that organizations/schools provide appropriate policies and increase the special education teachers' well-being in Ho Chi Minh City, Vietnam

Architecture Parallel for the Renewable Energy System

This chapter present one possible evolution is the parallel topology on the high-voltage bus for the renewable energy system. The system is not connected to a chain of photovoltaic (PV) modules and the different sources renewable. This evolution retains all the advantages of this system, while increasing the level of discretization of the Maximum Power Point Tracker (MPPT). So it is no longer a chain of PV modules that works at its MPPT but each PV module. In addition, this greater discretization allows a finer control and monitoring of operation and a faster detection of defects. The main interest of parallel step-up voltage systems, in this case, lies in the fact that the use of relatively high DC voltages is possible in these architectures distributed

A SOCIAL SURVEY ON COMMUNITY RESPONSE TO ROAD TRAFFIC NOISE IN HANOI

Joint Research on Environmental Science and Technology for the Eart

An efficient adaptive fuzzy hierarchical sliding mode control strategy for 6 degrees of freedom overhead crane

The paper proposes a new approach to efficiently control a three-dimensional overhead crane with 6 degrees of freedom (DoF). Most of the works proposing a control law for a gantry crane assume that it has five output variables, including three positions of the trolley, bridge, and pulley and two swing angles of the hoisting cable. In fact, the elasticity of the hoisting cable, which causes oscillation in the cable direction, is not fully incorporated into the model yet. Therefore, our work considers that six under-actuated outputs exist in a crane system. To design an efficient controller for the 6 DoF crane, it first employs the hierarchical sliding mode control approach, which not only guarantees stability but also minimizes the sway and oscillation of the overhead crane when it transports a payload to a desired location. Moreover, the unknown and uncertain parameters of the system caused by its actuator nonlinearity and external disturbances are adaptively estimated and inferred by utilizing the fuzzy inference rule mechanism, which results in efficient operations of the crane in real time. More importantly, stabilization of the crane controlled by the proposed algorithm is theoretically proved by the use of the Lyapunov function. The proposed control approach was implemented in a synthetic environment for the extensive evaluation, where the obtained results demonstrate its effectiveness. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Risk factors of dengue fever in an urban area in Vietnam: a case-control study

BackgroundDengue is a mosquito-borne flavivirus present in many metropolitan cities of tropical countries.MethodsDuring and after the dengue season (September 2018 to January 2019), we conducted a case-control study in order to determine the risk factors for dengue fever in Hanoi city, Vietnam. 98 dengue patients and 99 patients with other acute infections, such as Hepatitis B virus infection, were recruited at Department of Infectious Disease of Bach Mai national hospital in Hanoi. Patients were interviewed using a structured questionnaire covering demographic, housing, environmental factors and knowledge, attitude, and practice on dengue prevention and control. Univariate analysis and multivariable logistic regression were used to determine the risk factors of dengue status.ResultsThe mean score of knowledge items and practice items was only 7.9 out of total 19 points and 3.9 out of total 17 points, respectively. While the mean score of attitude items was 4.8 out of total 6 points. Multivariable logistic regression indicated that older patients had lesser risk of getting dengue infection as compared to younger adults aged 16-30, and patients living in peri-urban districts were less likely to suffer of dengue fever than patients living in central urban districts (OR=0.31; 95% CI 0.13-0.75). This study could not find any association with occupation, water storage habit, knowledge, attitude, or practice on dengue prevention.ConclusionsAll patients had a relatively low level of knowledge and practice on dengue prevention and control. However, the attitude of the participants was good. We found that age group and living district were the risk factors correlated with the dengue status. Communication programs on raising dengue awareness should be repeated all year round and target particular groups of adolescents, younger adults, landlords and migrants from other provinces to improve their knowledge and encourage them to implement preventive measures against dengue fever

Transformation Chlorophyll a of Spirulina platensis to Chlorin e6 Derivatives and Several Applications

BACKGROUND: Spirulina platensis contains a large amount of chlorophylls, chlorophyll a, that are starting materials to synthesize functionalized chlorins. Chlorin e6 (Ce6) as well as its derivatives are second generation sensitizers using in photodynamic therapy (PDT) of various cancers. In this study, we transfer chlorophyll a of S. platensis to Ce6derivatives and determine their several applications. AIM: to evaluate the effects of Ce6 derivatives to treat cancer cells. METHODS: Ce6 trimethylester was created from methyl pheophorbide a2 in S. platensis provided by the Hidumi Company, Nghe An province, Viet Nam. Hela cells were incubated with Ce6 trimethylester and the irradiated with the diode laser dose of 1.2 J/cm2/min through the system of filters £ 650 nm. MTT assay and clonogenic assay were used to determine survival rate and cloning efficiency of cells. Antimicrobial effect of Ce6 trimethylester with halogen light were studied with Propionibacterium acnes VTCC 0218 and Staphylococcus aureus VTCC 0173. RESULTS: From dry biomass (700 g) of S. platensis, after extracting chlorophyll a and methanolysis, 4.2 g of methyl pheophorbide a was obtained. The reaction to give Ce6 trimethylester with 82% yield was performed with potassium hydroxide (KOH) in MeOH/THF/CHCl3. After irradiation with a 650 nm laser at 1.2 J, the cell viability in all samples decreased with Ce6 trimethylester treatment, the survival declining trend of Hela cells treated with Ce6 trimethylester were proportional when concentration of Ce6 trimethylester increased. The rate of colony formation was declined as the concentration of Ce6 trimethylester treated was increased. The growth of both S. aureus and P. acnes can be inactivated by Ce6 trimethylester PDT. The MIC99 value against P. acnes VTCC 0218 and S. aureus VTCC 0173 of Ce6 trimethylester with halogen light was 1.25 μg/ml. CONCLUSION: The Ce6 trimethylester from S. platensis cultivated in Viet Nam could be used as a potential photosentizer for photodynamic therapy for treatment of cancer and acne

Depolarization Property of Cirrus Clouds Over Hanoi

Cirrus cloud is one of the most commonly occurring cloud types globally. The clouds are found mainly to consist of floating ice crystals, which can reflect strongly incoming radiation. Lidar measurements provide an opportunity to study the microphysics and ice compositions of cirrus clouds. We have developed a polarization lidar system to measure the depolarization characteristics of the lower atmosphere over Hanoi. From our measurements of cirrus clouds over the period from 2010 to 2012, the depolarization ratio of cirrus clouds is found to be very high ranging from 20% up to 80{\%}, indicating large fraction of backscattering from ice crystals. We find a trend of increasing depolarization ratio with height and decreasing temperature. We also compare our lidar measurements with other results obtained by lidar technique in other regions of the world