Structural and Optoelectronic Properties of CdSe Tetrapod Nanocrystals for Bulk Heterojunction Solar Cell Applications

Semiconducting CdSe tetrapod nanoparticles were prepared, and their structural and optical properties were examined. The surface capping molecule, octylphosphonic acid, was replaced with butylamine after the particle synthesis. The exchange of surface ligands changed the physical properties of the nanocrystals, which resulted in a slight decrease in the nanoparticles size. The effects of changing surface ligands of CdSe tetrapod nanocrystals on the structural and optoelectronic properties were investigated, and it was found that the surfactant of nanoparticles could affect the device performance by enhancing the charge carrier separation at the active layer interfaces. Power conversion efficiency of the bulk heterojunction solar cells having the structure of glass/ITO/PEDOT:PSS/(CdSe + PCPDTBT)/Al was improved from 1.21% to 1.52% with the use of ligand-exchanged nanoparticles

Examining Vietnam's Success in Controlling COVID-19 Pandemic in Terms of People's Behavior

To deal with an unprecedented pandemic known as COVID-19, every country has developed its own policies to prevent the expansion of Coronavirus. The purpose of this study is to investigate Vietnam’s success in controlling the spread of COVID-19 epidemic from the perspective of people’s behavior. This study applied the Health Belief Model developed by Don Nutbeam and Elizabeth (2004). An online survey engine (docs.google.com/forms) and an offline survey were employed to collect data from citizens in Hanoi, Ho Chi Minh City, Quang Ninh, Haiphong and other cities. The statistical analysis used 423 questionnaires from 450 respondents, mainly aged 18 to 35. The results demonstrated that people's awareness of COVID-19 as well as their behaviors have contributed significantly to the successful efforts to prevent and control the disease in Vietnam. Keywords: Covid-19 pandemic, controlling Covid-19, people’s behavior, behavior, Vietnam DOI: 10.7176/EJBM/13-6-07 Publication date:March 31st 202

Measuring citizen's satisfaction when using E-Government online public services: Lessons from Vietnam

This study aims to evaluate the factors affecting the satisfaction of citizen when using online public services through data collected from direct surveys of people. Research results show that Quality of online public services, Citizen's awareness, Privacy and security, Trust and accessibility affect citizen's satisfaction when using online public services. Based on these results, the study also gives some discussion and governance implications for researchers as well as policy-makers in improving citizen's satisfaction as well as attracting more users for online public services in Vietnam context

Drought stress - related functional characterization of transcription factor GmNAC085 in soybean

Studies on soybean GmNAC085 transcription factor revealed that the gene expression in plants was induced by water shortage treatments and its overexpression in the model plant Arabidopsis displayed improved plant tolerance characteristics towards drought stress. In this study, we continued analyzing the biological functions of GmNAC085 using transgenic soybean system overexpressing GmNAC085 gene, by targeting at a number of plant physiological features and biochemical activities in response to limited water growing condition. Compared to the wild-type, the transgenic line demonstrated that it possessed stress tolerance characters, including enhanced elongation of taproot, minimized reduction of shoot growth, lower intracellular H2O2 content and stronger peroxidase enzyme activity under drought condition. The results of this study therefore suggest the transgenic plants had better drought tolerance and the GmNAC085 plays important role in aiding plants to cope with water deficit condition, probably via regulating the growth of roots and shoots, and activities of reactive-oxygen-species- scavenging enzymes

Investigation on Air Pollution in Vietnam : Concentration of Water-soluble Ions in Suspended Particulate Matters

Joint Research on Environmental Science and Technology for the Eart

ANALYSIS OF THE POPULARITY OF VOCABULARY USED WHEN PERFORMING SPEAKING ACTIVITIES IN THE CLASS OF FIRST-YEAR ENGLISH LANGUAGE STUDENTS IN THE DIRECTION OF DISCOURSE ANALYSIS

Vocabulary learning is extremely important when learning a foreign language. Fluency in a language depends on vocabulary and its use in specific situations. Speaking well is using vocabulary flexibly and speaking fluently. Researching the popularity of vocabulary is analyzing the prevalence of vocabulary used by linguistics students in communication from discourse analysis. This is a topic the research team is working on. This project will help the researchers learn about common vocabulary that students often use to communicate outside or in the classroom. Thereby understanding whether the vocabulary that students use is diverse, rich, and for the right purpose or not. This study will help students have a more comprehensive view of the ways to use words in communication. In addition, it also helps students improve their communication vocabulary, helps in exams and can be useful for later work. In this study, the research team will investigate the students' ability to use spoken vocabulary, i.e., frequency and extent of vocabulary usage.  Article visualizations

Online Tests in the Trend of Education 4.0: An Empirical Study in Mathematics at High Schools of Can Tho City

In the trend of Education 4.0, the assessment of learning results through online tests is increasingly widespread and important because of its usability and mobility. In addition, it is also adaptable in the volatile situations of today's society such as natural disasters, epidemics, war, etc. The paper presents the results of an empirical study in Mathematics at high schools in Can Tho city on the comparison of outcomes between online tests and paper tests. The initial statistical analysis results show that the evaluation of learning results by online tests has high consensus among the experimental group. Furthermore, the advantages and suggestions for improvement are also pointed out and discussed in this work

Area yield crop insurance in Vietnam : an analysis from the demand side

When setting prices for each province, crop insurance companies should pay more attention to the relative level of basic risk and the correlation of losses across regions, instead of only focusing on the general level of risk exposure of each region. If farmers receive enough information about the insurance, the demand should be higher than the current rate of uptake. This study analyzes the demand of rice farmers for area yield crop insurance, which was designed and piloted during the period of 2011 - 2013 in Vietnam according to Decision No. 315/QD-TTg of the Prime Minister