The question of quality

Phuong-Thao T. Trinh, Thu-Hien T. Le, Thu-Trang Vuong, Phuong-Hanh Hoang (2019). Chapter 6. The question of quality. In Quan-Hoang Vuong, Trung Tran (Eds.), The Vietnamese Social Sciences at a Fork in the Road (pp. 121–142). Warsaw, Poland: De Gruyter. DOI:10.2478/9783110686081-011. Online ISBN: 9783110686081 © 2019 Sciendo / De Gruyte

Oxydation en voie humide des effluents des distilleries d'alcool à partir de canne à sucre en présence de catalyseurs Ru et Pt supportés sur TiO2 ou ZrO2

Vinasse is an aqueous effluent originating from ethanol production process from sugarcane. It is a dark brown effluent with an extremely high COD and a low BOD. The treatment of this type of effluent by wet air oxidation (WAO) was the subject of this study using noble metal catalysts supported on TiO2 and ZrO2 at 190-210 ° C under 50-70 bar air. The addition of Ru catalysts allowed the complete mineralization of the organic model pollutants (sucrose, polyethylene glycol, melanoidin) or the real effluents (cognac vinasse and cane vinasse); the Pt catalysts were also very effective, but acetic acid was formed as an intermediate which was difficult to be converted. Under these conditions, the organic nitrogen was converted to ammonium. Whereas in the absence of catalyst, the ammonium ions were stable, the addition of a catalyst was capable of converting ammonium to dinitrogen and nitrate. The selectivity to N2 and NO3 - depended on the oxidizing reaction conditions (molar ratio nitrogen/metal). In general, platinum proved to be more selective to dinitrogen. Metal leaching was detected upon CWAO of effluents containing organic nitrogen. The leaching decreased and disappeared as nitrogen was mineralised and the dissolved metal redeposited on the solid catalyst. The continuous reactor tests confirmed the observations in the batch reactorLa vinasse est un effluent aqueux issu des distilleries d'éthanol produit à partir de mélasse de canne à sucre, caractérisé par une couleur intense, une forte Demande Chimique en Oxygène (DCO) et un faible Demande Biologique en Oxygène (DBO). Le traitement de ce type d'effluent par Oxydation en Voie Humide (OVH) a fait l'objet d'une étude sur catalyseurs métaux nobles supportés sur TiO2 ou ZrO2 à 190-210°C sous 50-70 bar d'air. L'addition de catalyseurs au Ru permet la minéralisation complète de la partie carbone des polluants modèles (saccharose, polyéthylène glycol, mélanoïdine) ou des effluents réels (vinasse de Cognac et vinasse de canne); les catalyseurs au Pt sont également très efficaces, mais ne convertissent que très peu l'acide acétique formé intermédiairement. Dans ces conditions, l'azote sous forme organique est converti en ammonium. Alors qu'en l'absence de catalyseur, les ions ammonium sont stables, l'addition d'un catalyseur est capable de convertir l'ammonium en diazote et nitrate. Les sélectivités relatives en N2 et NO3 - dépendent des conditions oxydantes de la réaction (quantité d'azote à traiter par rapport à la quantité de métal actif). De manière générale, le platine se révèle plus sélectif en diazote. Une lixiviation des métaux a été détectée au démarrage des réactions d'OVHC des effluents à cause de l'azote sous forme organique ; elle diminue et disparaît au fur et à mesure de la minéralisation de l'azote et le métal se redépose sur le solide catalytique. Les essais en réacteur continu confirment les observations en réacteur batc

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

First-principles study on the structural and electronic properties of single-layer MoSi2N4

Motivated by the successful exfoliation of a novel two-dimensional MoSi2N4 materials, in this work, we investigate the structural and electronic properties of a novel single-layer MoSi2N4 and the effect of strain engineering by using the first-principles calculations based on the density functional theory. The single-layer MoSi2N4 has a hexagonal structure with a space group of P6m1, which is dynamically stable. The material exhibits a semiconducting characteristic with an indirect band gap of 1.80/2.36 eV calculated by using the PBE/HSE functional. The conduction band minimum at the K point of the material originates from the Mo atom, while its valence band maximum at the G point is contributed by the hybridization between the Mo and N atoms. The electronic properties of the single-layer MoSi2N4 can be modulated with strain engineering, giving rise to a transition from a semiconductor to a metal and tending to a change in the band gap. Our results demonstrate that the single-layer MoSi2N4 is a promising candidate for electronic and optoelectronic applications

On Building a Community to Exchange and Share Sustainable Fashion Applications

Sustainable development is a standard plan for peace and prosperity for people and the planet, now and in the future, set forth by the 2030 Agenda for Sustainable Development, which was adopted by all United Nations member states and agreed to in 2015. The Sustainable Development Goals (SDGs) are an urgent call to action for all developed and developing countries in relation to global cooperation. Many factors cause environmental pollution, but the fashion industry is considered by the United Nations Conference on Trade and Development (UNCTAD) as the second most polluting industry in the world. It accounts for 10% of global carbon emissions due to the energy used in production, manufacturing, and transportation. In particular, the factors that strongly affect the environment in the fashion industry are the textile materials, the fabric dyeing industry, and the rapid development of fast fashion. The data was collected through an online survey of 101 fashion consumers and interviews with nine target audiences who need to buy and sell used clothes or are interested in buying and selling used clothes or sustainable fashion. Sustainable design is not a new concept, but it is still quite strange to the Vietnamese. Consumer ignorance about sustainable consumption and the harmful effects of the fashion industry on planet Earth is a big reason why consumers constantly plunge into the shopping vortex. The problem of wasteful and unsustainable fashion consumption is a big global problem at a time when the fashion industry is gradually emerging into the sustainable fashion movement. This is an opportunity to build a community by connecting consumers through their essential needs, helping them raise awareness, change their behavior, and make each individual part of a sustainable fashion community. They are thus contributing to sustainable development in the future. Keywords: SDGs, sustainable fashion, sustainable consumption, communit

The Impact of Personal Financial Literacy on the Choice of Lending Channel by Vietnamese Householders Who Just Escaped Poverty

Purpose: The Newly-Escaped-Poverty-List householders (NEPLH) in Vietnam served as the survey subjects for this study, which sought to determine the impact of "Personal Financial Literacy" on "The Probability of Using Lending Services of Vietnam Bank for Social Policies (P_VBSP)" and "The Probability of Using Informal Private Lending Services (P_ILC)".   Design/methodology/approach: Survey data were collected from 186 respondents, by structured online questionnaire with convenient non-probability sampling technique.  Aspects of personal financial literacy (FLi) such as personal financial knowledge (FL1), personal financial skills (FL2), personal financial attitude (FL3), and personal financial behavior (FL4) are measured. When respondents were divided into groups based on subgroup criteria (CVj), such as gender, age, marital status, role in the family, career, education level, religion, and number of years since being removed from the list of poor households, ANOVA techniques were used to examine differences in various aspects of personal financial literacy. The impact of FLi and subgroup variables (CVj) on P_VBSP and P_ILC was assessed using the binary logistic regression analysis technique.   Findings: Research results show that  there is a statistical difference in the average score of FL1, FL2, FL3 and FL4. The research findings also show that FL2, FL4, and "Career Status – CAR" have a positive impact on P_VBSP, while "Aged group - AGE", "Education level - EDU", and "Number of years since being removed from the list of poor households - YEAR" have a negative impact on P_VBSP. Meanwhile, the P_ILC is positive influenced by the AGE factor and moves in the opposite direction of FL2, FL4, EDU, and YEAR.   Research, Practical & Social implications: The research findings provide the basis for governance implications as well as policy recommendations to promote financial literacy among the NEPLH in Vietnam, encouraging them access policy lending services from the Vietnam Bank for Social Policies, and at the same time help them stay away from informal private lending services, thereby helping them to reduce poverty and achieve sustainable economic development family.   Originality/value: A theoretical framework for personal finance literacy, including (i) financial knowledge, (ii) financial attitude, (iii) financial skills, and (iv) financial behavior, has been developed by the authors after reviewing earlier studies. At the same time, it is more significant to measure financial literacy by objective assessment than relying on the subjective self-assessment of each respondent in the context of actual study in Vietnam. In the model analyzing the influence of personal financial literacy on the decision of Newly-Escaped-Poverty-List householders in choosing the Vietnam Bank for Social Policies or Informal Private Credit Channels, the authors also took into account additional factors including gender, age group, marital status, role in the family, career, education level, religion, and number of years since being removed from the list of poor households

IMPACT OF THE EVFTA AGREEMENT: A STUDY ON VIETNAM'S EXPORTED GOODS

Abstract The research aims to assess the quantitative impact of the Vietnam-European Union Free Trade Agreement (EVFTA) on Vietnam's export growth to the EU market. The study employs quantitative analysis using the SMART model with data on export turnover and scenarios of tariff reduction to 0% when EVFTA takes effect. Based on the export turnover data and necessary parameters, the analysis results show an increase in Vietnam's exports to the EU market when EVFTA becomes effective. As a result, the research proposes some implications to promote Vietnam's export activities to the EU in the future

Preparation and characterization of magnesium hydroxyapatite coatings on 316L stainless steel

Magnesium hydroxyapatite coatings (MgHAp) were deposited on the surface of 316L stainless steel (316L SS) substrates by electrodeposition technique. Different concentrations of Mg2+ ion were incorporated into the apatite structure by adding Mg(NO3)2 into electrolyte solution containing 3×10-2 M Ca(NO3)2, 1.8×10-2 M NH4H2PO4 and   6×10-2 M NaNO3. With Mg2+ concentration 1×10-3 M, the obtained coatings have 0.2 wt% Mg2+. The influences of scanning potential ranges, scanning times to deposit MgHAp coatings were researched. The analytical results FTIR, SEM, X-ray, EDX, thickness and adhension strength showed that MgHAp coatings were single phase of HAp, fibrous shapes, thickness 8.1 µm and adhesion strength 7.20 MPa at the scanning potential ranges of 0÷-1.7 V/SCE and scanning times of 5 scans. Keywords. 316L SS, Electrodeposition, MgHAp

Multiple-Symbol Differential Detection for Spatial Modulation

Approximately 3 dB Signal-to-Noise Ratio (SNR) loss is always paid with conventional Differential Spatial Modulation (DSM) as compared to coherent Spatial Modulation (SM). In this paper, a Multiple-Symbol Differential Detection (MSDD) technique is proposed for DSM systems to mitigate the loss due to differential detection. The new scheme can greatly narrow the 3 dB performance gap by extending the observation interval for differential decoding. The technique uses maximum-likelihood sequence detection instead of traditional symbol-by-symbol detection, and is carried out on the slow, flat Rayleigh fading channel. A generalized decision metric is derived for an observation interval of arbitrary length. It is shown that for a moderate number of symbols, MSDD provides approximately 1.5 dB performance improvement over the conventional differential detection. In addition, a closed-form pairwise error probability and approximate bit error probability (BEP) are derived for multiple-symbol differential spatial modulation. Results show that the theoretical BEP matches well the simulated one. The BEP is shown to converge asymptotically with the number of symbols in the observation interval to that of the differential scheme with coherent detection

LEARNING IDIOMS FOR ENGLISH MAJORS: VIETNAMESE STUDENTS’ PERCEPTIONS OF DIFFICULTIES AND LEARNING STRATEGIES

Learning idioms play an influential role in language generally and in English notably. Comprehending idioms assists language learners in integrating culture, enhancing skills, and ameliorating English levels. Numerous studies have analyzed the function of idioms in second language acquisition (Cieślicka, 2015). This study investigates the difficulties and strategies used in learning idioms by English-majored students at a regional public university (PU) in the south of Vietnam. This paper furnishes data showing learners’ perceptions of facing complications and learning methods. The samples consisted of 150 undergraduate EFL students from English-medium instruction programs. The data was analyzed by utilizing descriptive and inferential statistics. The findings reveal that students struggle to understand idiomatic terms without specific, understandable contexts. Furthermore, the results indicate that the most frequently employed strategies are guessing the meaning of idioms, learning idioms through keywords, and learning from a range of sources, particularly via media. The findings also mentioned that low-proficiency and high-proficiency students encounter identical challenges, with no significant differences. The study's results revealed that the majority of students have difficulty acquiring, recognizing, and interpreting idioms. The findings indicated that guessing the implication of idioms is the most used strategy.  Article visualizations