VOLATILE COMPOSITION, ANTIOXIDANT PROPERTY AND ANTIMICROBIAL ACTIVITIES AGAINST FOOD-BORNE BACTERIA OF VIETNAMESE THYME (Thymus vulgaris L.) ESSENTIAL OIL

The essential oil (EO) obtained from the leaves of the thyme (Thymus vulgaris L.) grown in Vietnam was found to contain thymol (39.79%), cymene (17.33%), and γ-terpinene (13.45%) as the main volatile components. The antimicrobial activities of this oil were screened against several food-borne bacteria and fungi species. Significant growth inhibition effects against food-borne bacteria Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Salmonella Typhimurium were observed using the standard disc diffusion method. Thyme EO showed the antibacterial effect against all the test pathogenic strains with the inhibition zones were 23.3 ± 0.4 mm, 24.7 ± 0.4 mm, 29.0 ± 0.7 mm, 32 ± 0.7 mm in diameter against B. subtilis,  E. coli, S. Typhimurium and S. aureus, respectively. The minimum inhibitory concentration (MIC) determined by micro-dilution method in MHB liquid medium was 1.56 µl/ml. The bactericidal concentrations (MBC) was 3.13 µl/ml for three isolates from B. subtilis,  E. coli, and S. aureus, while the MBC tested for S. typhi was 1.56 µl/ml. The antifungal properties of the thyme EO were also determined in this study against three important pathogenic fungi such as Candida albicans, Rhizoctonia solani and Fusarium oxysporum with the inhibition zones ranging approximately from 23.20 ± 0.06 to 44.10 ± 0.03 mm. On the other hands, the results also showed the antioxidant activity of Vietnamese thyme EO and suggested that thyme EO can be applied in food industries as natural flavoring preservatives/additives to control food spoilage and food born bacteria and fungi

Barriers and Coping Strategies of Students with Disability During Inclusive Learning in Higher Education

Abstrak: JJumlah penyandang disabilitas yang mengikuti sistem Pendidikan inklusi di perguruan tinggi semakin meningkat seiring dengan adanya Kartu Indonesia Pintar (KIP) Kuliah. Penelitian ini bertujuan untuk mendeskripsikan tantangan hambatan yang dihadapi mahasiswa disabilitas selama mengikuti kuliah inklusi dan strategi koping mahasiswa dalam mengatasinya. Penelitian ini bersifat deskriptif kualitatif dan data dikumpulkan dengan teknik interview, observasi, dan dokumentasi. Data dianalisis dengan metode analisis studi kasus. Hasil penelitian menunjukkan bahwa mahasiswa tunanetra menghadapi hambatan belajar terkait teks, gambar atau simbol/angka, sedangkan mahasiswa tunadaksa memiliki hambatan terkait aktiVitas fisik. Strategi koping yang dilakukan oleh mahasiswa adalah dengan menggunakan Assistive Technology (AT), meningkatkan komunikasi dengan dosen, dan melakukan diskusi kelompok. Dari temuan di atas, disimpulkan bahwa teknik pengajaran dan materi perkuliahan harus beaptasi dengan kebutuhan murid dan dapat digunakan secara universal.Abstract: The number of disabled students enrolled in the inclusive system in higher education has increased due to a card used to access colleges issued by the Indonesian government known as Kartu Indonesia Pintar Kuliah (KIP Kuliah). The research aims to describe learning barriers encountered by students with visual and physical disabilities during inclusive class and their coping strategies to overcome this predicament. The research is qualitative descriptive, and data were collected by interview, class observation, and documentation. The data were analyzed by using the case study analysis method. The results indicate that written material containing text, pictures, and symbols/numbers are barriers for visually disabled students, while physically disabled students have barriers in terms of class that requires physical activities. Students’ coping strategies are using Assistive Technology (AT), increasing communication frequency with the lecturers, and conducting study groups after class. It is concluded that the lecturer’s teaching technique and material should be adapted to meet the students’ needs and should be universal

TÍNH TOÁN KHẢ NĂNG TIẾP NHẬN CHẤT Ô NHIỄM CỦA ĐẦM THỊ NẠI (TỈNH BÌNH ĐỊNH)

Based on the surveys at Thi Nai lagoon in rainy season (October, 2013) and dry season (May, 2014) and the documents on natural conditions, socio-economic status of Thi Nai lagoon, receiving capacity of pollutants in the lagoon was calculated on the basis of environmental standards, using Delft3D model. Calculation results showed that at present Thi Nai lagoon no longer has capacity to receive ammonium and nitrate. Until 2025, besides two parameters, Thi Nai lagoon will no longer have capacity to receive phosphate. In addition, the receiving capacity of the lagoon will be reduced for most of parameters while receiving capacity of lagoon for BOD5 and TSS will increase. Regarding heavy metals, receiving capacity of lagoon will be reduced, especially for Zn (12.18%).Dựa trên các số liệu khảo sát về chất lượng nước tại đầm Thị Nại mùa mưa (tháng 10/2013) và mùa khô (tháng 5/2014), các tài liệu thu thập về điều kiện tự nhiên, kinh tế - xã hội ven đầm và các tiêu chuẩn môi trường, đã tính toán khả năng tiếp nhận các chất ô nhiễm trong đầm thông qua sử dụng mô hình Delft3D. Kết quả tính cho thấy, hiện tại đầm Thị Nại không còn khả năng tiếp nhận amoni, nitrat. Tới năm 2025, ngoài 2 thông số này đầm Thị Nại sẽ không còn khả năng tiếp nhận phosphat. Ngoài ra, khả năng tiếp nhận của đầm sẽ giảm đi đối với hầu hết các thông số (3,44%, 1,84%, 0,02%, 12,18%, 0,46% đối với COD, Cu, Pb, Zn và As, tương ứng), trong khi khả năng tiếp nhận BOD5 và vật lơ lửng tăng lên. Liên quan đến các kim loại nặng, khả năng tiếp nhận của đầm cũng giảm đi nhiều nhất là Zn (12,18%)

Impairment of Assets Under Perspectives of International and Vietnamese Accounting

This study investigates the impairment of assets on financial reportings of three separate entities - Vietnam Prosperity Joint-Stock Commercial Bank (VPBank), The Bank of East Asia (BEA) and The Nestlé Group - in the financial year of 2017. By bringing out the differences between international accounting system of asset impairment (IAS 36) and Vietnamese accounting system (VAS), this research has determined the gap between two sets of financial statements under IFRS and VAS in conveying the business performance and financial position. The empirical results show Vietnam’s necessary for a convergence in asset impairment with international accounting system. Therefore, we provide some recommendations for Vietnam in applying asset impairment regarding to IAS 36 partly or completely. Keywords: Asset impairment, International accounting, Vietnamese accounting. DOI: 10.7176/RJFA/10-12-07 Publication date:June 30th 2019

RESEARCH ON THE MANUFACTURING MAGNESIUM FROM THANHHOA DOLOMITE BY PIDGEON PROCESS

The magnesium and magnesium alloys has applied widely in different industrial aspects in Vietnam in the modern life. Especially, the products from magnesium alloys implementing in the automotive have increased rapidly since the car elements tend to be generated by the light alloys in order to save the fuel. However, in the current time, Vietnam has no factories to produce the magnesium to adapt the domestic demand although it owns an enrich resource of raw materials. This research indicates the possibility of using the dolomite ore in Thanhhoa – Vietnam to make the magnesium as well as evaluate the primary factors like recovering temperature, reducing agent rate, recovering time having effect on the reduction efficiency of Thanhhoa dolomite by metallothermic method in vacuum (Pidgeon Process). This is basic process, low investment and suitable for the small and medium scales in Vietnam. The experiment includes heating, indicating the chemical ingredients and recovering experiment on the dolomite after calcination (dolime) by using ferrosilicon. The thermodynamic model is created to estimate the recovering efficiency in the Pidgeon. The result shows that the CaO/MgO molar ratio of calcination dolomite in Thanhhoa is nearly 1.5 which is suitable to produce magnesium in the case of highly-required efficiency and pureness. Besides, the result from the furnace of the experiment is lower than the one in the model. The samples are set up to check the influence of the rate of ferrosilicon in the compound. The result indicates that the ideal efficiency reaches 85 % with 30 % ferrosilicon. Moreover, the study confirms that the optimal operating conditions in this process are recovering during three hours at 1200 °C and 100 Pa pressure. This result proves the potential application of Thanhhoa dolomite in the industry suitable with the current condition in Vietna

An Analytical Framework Considering the Effects of Online Teaching Quality on Student Satisfaction

COVID-19 spreads across the world in late 2019 has affected to several aspects of social life. One of the most important sectors, which face difficulties was education, thus most universities have transferred from traditional education to online education through the internet to make their academic year going. This study aims to review the effects of online teaching quality on student satisfaction, a positive attitude resulting from an evaluation of students’ online teaching experience in higher education. Through applying the SERVQUAL model to measure the effects of online teaching quality on students’ satisfaction, it can be expected to get better the online teaching quality of higher education institutions in Vietnam. Keywords: Online teaching, student satisfaction, higher education, COVID-19, educational institution. DOI: 10.7176/EJBM/13-6-08 Publication date:March 31st 202

Effect of Polypyrrole on the Electrical, Dielectric and Mechanical Properties of Waterborne Epoxy Coatings

In this context, conducting composite based on waterborne epoxy system and polypyrrole (PPy) was investigated. The polypyrrole was synthesized by chemical oxidation polymerization. Its morphology and chemical structure were confirmed by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Then, PPy was well-dispersed in the epoxy coating and had a good compatibility with the matrix. The effects of PPy on dielectric, electrical and mechanical properties of epoxy/PPy composites was examined. The dielectric constant and electrical conductivity of the coatings increased with addition of PPy fillers. Over to 15 wt. % of PPy loading, the volume resistivity of samples slightly decreased from 6.7 × 1010 to 1.5 × 1010 Ω cm. In contrast, the presence of PPy diminished both impact and abrasion resistance of the epoxy/PPy composites, down to 160 kg cm and 10.2 L/mil, respectively, but they stayed acceptable for the coatings. The results reveal that the epoxy containing polypyrrole is suitable for various electrical and dielectric applications

EFFECT OF FISH SCALE COLLAGEN ON SOME CHARACTERISTICS AND DRUG RELEASE OF CARRAGEENAN/COLLAGEN/ALLOPURINOL FILM

ABSTRACT - QMFS2019Collagen from fish is attracting a lot of attention thanks to its high absorbance ability, biocompatibility as well as non-religious obstruction and cheap sources. It could be applied in many fields, for example: food, cosmetic, or biomedicine. Using of collagen also helps to reduce the environment pollution from fish scale waste in fish processing. In this study, collagen extracted from Vietnamese fresh-water tilapia fish scales was used in combination with carrageenan for the improvement of drug release control. The influence of fish scale collagen content on morphology, thermal behavior and drug release from carrageenan/collagen/allopurinol composite film was evaluated by methods such as field emission scanning electron microscopy (FESEM), differential scanning calorimetric (DSC) and ultraviolet-visible spectroscopy (UV-Vis). From the DSC data, FESEM analysis and drug release of carrageenan/collagen/allopurinol composite films, the most suitable collagen in composite film is 5 wt.%

Fabrication and Evaluation of the Photocatalytic, Antibacterial Activity of Ag–TiO2_2 Thin Film

Ag–TiO2 thin film was fabricated by DC magnetron sputtering and photoreduction methods. Characteristics of the film such as surface area, crystal structure, and chemical composition were investigated by using scanning electron microscope (SEM), X–ray diffractometry (XRD) and UV–vis spectra. The photocatalytic activity of Ag–TiO2 thin film was determined by the degradation of methylene blue (MB) solution under various irradiation conditions. The antibacterial property of Ag–TiO2 thin film was conducted in E. coli bacteria. Results showed that the photocatalytic and antibacterial property of Ag–TiO2 thin film are better than those of pure TiO2 thin film in the visible region. Ag–TiO2 thin film shows a great potential application in the antibacterial and environment field

Survey on Vietnamese teachers’ perspectives and perceived support during COVID-19

The COVID-19 pandemic has caused unprecedented damage to the educational system worldwide. Besides the measurable economic impacts in the short-term and long-term, there is intangible destruction within educational institutions. In particular, teachers – the most critical intellectual resources of any schools – have to face various types of financial, physical, and mental struggles due to COVID-19. To capture the current context of more than one million Vietnamese teachers during COVID-19, we distributed an e- survey to more than 2,500 randomly selected teachers from two major teacher communities on Facebook from 6th to 11th April 2020. From over 373 responses, we excluded the observations which violated our cross-check questions and retained 294 observations for further analysis. This dataset includes: (i) Demographics of participants; (ii) Teachers' perspectives regarding the operation of teaching activities during the pandemic; (iii) Teachers' received support from their schools, government bodies, other stakeholders such as teacher unions, and parents' associations; and (iv) teachers' evaluation of school readiness toward digital transformation. Further, the dataset was supplemented with an additional question on the teachers' primary source of professional development activities during the pandemic