ABSTRACT With the ever-increasing development of technology, online teaching is more readily accepted as a viable component in teaching and learning, and blended learning, the combining of online and face-to-face learning, is becoming commonplace in many higher education institutions. Definitely, challenges cannot be denied; however, it has been suggested and deployed globally including Vietnam. To some extent, both teachers and students present their positive points of view on this learning approach. However, there are a huge number of students expressing their lack of understanding the blended learning, which negatively affects their attitudes towards deployment of this learning approach as well as particular reference to motivation and interest. This paper is to assess the English majors’ perceptions on blended learning environment at tertiary level, which especially affects their learning the writing skills. Results of the study are absolutely helpful for the author to understand the students’ perceptions of the effects on the blended learning; then, she can give some suggestions to enhance the learning of writing skills in the light of blended learning. Key word: Blended learning, academic writing, perception

The electricity obtained from the photovoltaic (PV) system highly depends on various factors such as geographical location, solar radiation, weather conditions and orientation of solar panels. The electricity produced by the solar PV system can be assessed by using simulations. This paper presents a technical feasibility assessment of a 10 kWp rooftop solar PV system for a household in Thu Dau Mot City, Vietnam. The study presents the amount of electricity produced, the performance of the PV system and the system potential to reduce CO2 emissions into the environment. The designing and evaluating of the system performance is done by PV*SOL, PVsyst and PVGIS software. The project provides useful information for the pre-feasibility assessment phase of a residential solar PV project in Vietnam.

In Vietnam, deviant behaviour in adolescents is increasingly popular and gradually becomes a major concern of the whole society. The purpose of this study is to identify Factors affecting deviant behavior of Vietnamese adolescents, including: Nature of adolescence (Biology, Intelligence and Cognitive functions) and Nurture (Family atmosphere, Education environment, Media and technology, Peer Pressure, and Religion and Politics). 426 survey samples were collected to serve the data analysis process as well as all hypotheses were examined by using STATISTIC 10 ver., LISREL 8.8 with Covariance Matrix, and LISREL model. This research showed that Nature of adolescence, Family atmosphere, Education environment, Social media and technology, Peer pressure have significant influence on deviant behavior of adolescents in Vietnam. The research also indicated that deviant behavior of Vietnamese adolescents is not affected by Religion and politics. The study also makes suggestions to improve morality and foster personality for adolescents in Vietnam, makes a small contribution to the country's further development.

Coffee is among the favorite drinks in Vietnam and many other countries. Production and consumption of coffee have released a huge amount of spent coffee ground. This study aimed to determine phenolic acids and fatty acids of spent coffee grounds collected in Ho Chi Minh city and how phenolic acid profile was affected by different environmentally friendly extractants. The results showed that average level of chlorogenic acid in ethanol/water extracts (840.4 779.9 ug/g) was significantly higher compared to water extracts (300.0 ug/g). Furthermore, the average total level of phenolic acids in ethanol/water extracts (1215.3 ug/g dry weight) was greater than that in the water extracts (779.9 ug/g dry weight). This indicated that ethanol/water outperformed water in regard to extraction of phenolic acids in the spent coffee grounds. Oil extracted from the spent coffee grounds was rich in linoleic acid (61 ug/g) and palmitic acid (47 ug/g). The findings of our study showed that the spent coffee grounds originating in Vietnam are a good source of phenolic acids and polyunsaturated fatty acids that could be utilized for food and nutraceutical production.

Heavy metal pollution is a major problems in the environment. The impact of toxic metal ions can be minimized by different technologies, viz., chemical precipitation, membrane filtration, oxidation, reverse osmosis, flotation and adsorption. But among them, adsorption was found to be very efficient and common due to the low concentration of metal uptake and economically feasible properties. In this review paper, Fe–Mn binary oxide incorporated into diatomite (Fe/Mn-diatomite) was prepared by a simple coating method , and removal of Cu(II) from aqueous solutions. The effects of three independent variables including initial ion concentration, removal time, and adsorbent dosage were investigated on the maximum adsorption of Cu (II). The optimum conditions for the adsorption of Cu(II) was obtained: 75 ppm of initial ion concentration, 150 min of removal time and 1.5 g/l of adsorbent. The maximum removal efficiencies of Cu(II) was obtained 86.25%. The results showed that Fe/Mn-diatomite was apable of treating copper metal in wastewater.

Declining supplies of fossil fuels, increasing population, global industrialization and demand for transportation fuels has triggered an increase in the demand for renewable energy sources. To address such problems most of the green research in the recent years has focused on the development of bioethanol (23 MJ/L) as a substitute to conventional gasoline (34.3 MJ/L) based fuels owing to the similarity in energy density values in addition to several other advantages (American Council on renewable energy, 2010). Second-generation biofuels are derived from lignocellulosic biomass or woody crops, mostly coming from agricultural residues. Extraction of fuel from such biomass is difficult because of their recalcitrant nature (corn stover, rice straw, wheat straw, sugar cane and sweet sorghum). Lignocellulosic fuel has the potential to solve several problems (food competing with fuel) that are currently associated with first generation biofuels. Moreover, lignocellulosic fuels can supply a larger proportion of the global fuel leading to sustainability at lower cost, and with greater environmental benefits (Liz Marsall, 2009). The production of ethanol from the complex sugars in leaves and stalks is a promising strategy to radically broaden the range of possible ethanol feedstock. Keywords: lignocellulose, bioethanol, biomass, pretreatment, hydrolysis, fermentation.

This study aims to assess environmental risk using the improved Nemerow index and the principal component analysis (PCA) method in Long Thanh's Industrial Park in Dong Nai Province. The study was implemented in five industrial parks of Long Thanh District in 2019. The result showed that Loc An - Binh Son industrial park was at extreme high risk of the level (6.7). Three industrial parks of Long Thanh, Go Dau and An Phuoc were high-risk (from 3 to 5) respectively. On the other hand, Long Duc Industrial Park has obtained no environmental risk.

The wastewater treatment plant is an extremely important infrastructure to ensure the quality of life, water use of human life, and other ways to ensure water quality for the natural environment. In the operation of it, there are always potential hazards affecting the health of the workers working in the factory. The study was performed using the Semi-quantitative risk assessment method to calculate the values of operational risks in the water treatment plant (WWP). The results of the study obtained 18 high potential hazards that may lead to the present in the water treatment process. The hazards were the leakage of deodorizing towers and the generation of toxic emissions of dead microorganisms that have the highest value with a risk scale of 20 points- frequent impacts on employees. The study has also identified the dangers present in WWP and this will be the premise for mitigating solutions for problems occurring at its.

Environmental issues such as the wastewater have influenced each aspect of our lives. For human and environmental health protection, it is necessary to remove excess zinc in industrial wastewaters before discharging them to environment. Modified diatomite displayed larger surface area and pore volumes in comparison with untreated natural diatomite, which favored heavy metals sorption behavior. In this study, the removal of Zn(II) ions from aqueous solution was studied using Fe/Mn modified diatomite sample at different adsorption parameters such as contact initial metal ions concentration, dosage of Fe/Mn-Diatomite and ionic strength Na2CO3 on ionic Zn2+ adsorption capacity of diatomite modified. The residual zinc concentration in the solution was determined using flame atomic absorption spectroscopy. The results showed that: the gravitational increase increases with increasing time and then becomes almost stable, with 120 minutes timeliness; absorption increases when Fe/Mn-Ditomite is increased, absorption reaches 89.48% at a dose of 1.5 g/l; additional different concentrations Na2CO3 ranged from 0 ppm to 80 ppm the results showed that performance treatment Zn2+ of correspond 94,85%. This study could lay an essential foundation to develop modified diatomite for heavy metal removal from wastewater.

Bien Hoa City is an urban area of Dong Nai province located in the Southern key economic region. Currently, Bien Hoa City has 6 industrial parks in operation with large daily wastewater flow, causing environmental risks, especially from organic pollutants. The study applied the Nemerow risk index and the geographic information systems (GIS). The results showed that the industrial parks were mainly organic pollution levels including N-total, P-total, and Ammonium. The level of environmental risk from organic pollution was recorded in range of medium to very high levels, the ranked in descending order: Agtex Long Binh Industrial Park (P = 24)> Amata Industrial Park (P = 16)> Bien Hoa 2 Industrial Park ( P = 10),> Tam Phuoc Industrial Park (P = 5)> Loteco Industrial Park (P = 3). The results of the study provided good information for the management and improvement of wastewater quality in the industrial wastewater treatment plants of the industrial parks in Bien Hoa City.

Along with changes in Economy, Tourism and the influence of foreign waves, the market of Food Service in Vietnam has also changed to meet the needs of customers. At many restaurants in Vietnam, customer satisfaction can greatly affect restaurant revenue. Therefore, it is essential to determine which perceived quality factors affect customer satisfaction. The survey was conducted through questionnaires collected from 329 respondents, who experienced in restaurant services in Vietnam. In this paper, four factors are found that have influence on customer satisfaction in restaurants: Service quality, Product quality, Environment and Price. In addition, the research also gives some contributions based on the research results, helping businesses understand customers and meet customer satisfaction requirements in the restaurant.

Activity recognition is one of the preliminary steps in designing and implementing assistive services in smart homes. Such services help identify abnormality or automate events generated while occupants do as well as intend to do their desired Activities of Daily Living (ADLs) inside a smart home environment. However, most existing systems are applied for single-resident homes. Multiple people living together create additional complexity in modeling numbers of overlapping and concurrent activities. In this paper, we introduce a hybrid mechanism between ontology-based and unsupervised machine learning strategies in creating activity models used for activity recognition in the context of multi-resident homes. Comparing to related data-driven approaches, the proposed technique is technically and practically scalable to real-world scenarios due to fast training time and easy implementation. An average activity recognition rate of 95.83% on CASAS Spring dataset was achieved and the average recognition run time per operation was measured as 12.86 mili-seconds.

Corrosion of the bottom of the petroleum tank may lead to a product leak that could cause a fire or explosion resulting in damage to people and the environment, therefore the test of tank bottom corrosion is necessary to be conducted periodically to prevent the occurrence of the above problems. In non-destructive inspection, the Magnetic Flux Leakage (MFL) method relies on the variation of fluxes caused by defects on the surface of materials to detect corrosion, pitting, or imperfections, which is proved quite effectively with low cost. The project was implemented to develop a prototype of the MFL bottom detection device based on the research results in the world to improve corrosion survey capacity in industrial equipment, as well as to improve the expertise in the Research Team of electronics and automation in the fields of magnetic fields and sensors. As a result, an MFL model using permanent magnets and Hall sensors were fabricated. Survey experiments showed that the machine could detect corrosion defects up to 20% of steel wall thickness in the scanning speed range from 500 mm/s to 1130 mm/s. However, to meet the actual survey needs, the team must continue to improve the device in terms of sensitivity, scanning speed, the ability to operate automatically or semi-automatically, and register for a fire safety inspection.

Measuring environmental protection activities is a matter of great concern over the years. In this study, the indicators for evaluating environmental protection activities in industrial parks was built according to the PDSIR model and based on Vietnam's legal framework, including 18 main subjects and 35 indicators. The environmental performance index of industrial park (EPIIP) was established based on the multi-criteria evaluation method and the analytic hierarchy process method. The results of the study indicated that the VSIP I industrial park reached 68.95 points (relatively good level). Moreover, the results also showed that VSIP I was one of the industrial parks practicing good performance to protect environmental problems.

Nowadays, the benefits of ISO 14001:2015 abound, for minimizing environmental footprints, providing operational improvements, bringing lucrative business and improving the company’s image. There is an annual audit to decide if the company’s environmental management system meets the requirements of ISO 14001:2015. This is a significant audit that strongly affects the current certificate. The study to “Evaluate the efficiency of the environmental management system ISO 14001:2015 at the Vietnam Onamba Company” has been conducted to research the internal audit and examine any discordance in the environmental management system. The study carries out the internal audit of the environmental management system ISO 14001:2015 at VTO company by 3P method (P1: Paper check, P2: People interview, P3: Practice Observe). The result of the study showed a minor discordance at (6.2) Environmental Objectives and planning to achieve them. Regarding other clauses, they meet the requirements of the environmental management system. The result shows that the responsibility and careful observation of the company in controlling the system. The study evaluates reducing consumption (electricity, water, and chemicals) through collecting and comparing the data between 2017 and 2018. The results show the efficiency of reducing consumption: monthly electricity consumption reduced 21,86% (377 MWh); monthly water usage reduced 17,89% (1421 m3 ); annual chemical usage reduced from 3 to 6%.