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

Factors affecting intention to purchase organic agriculture products among Vietnamese

Globally, customer intention to purchase has become the essential part of the product and organization's success in the market. More recently, the idea has captured the attention of academic and policymakers alike. Therefore, the current article analyses product quality features such as agreeableness, emotional stability conscientiousness, openness to experience and extroversion on the intention to purchase organic agricultural products in the context of Vietnam. The study also analyses the mediating role of customer satisfaction between the association of product quality features and intention to purchase organic products in Vietnam. The present study uses questionnaires to collect data pertaining to the health sector of Vietnam. The current study employs the smart-PLS to analyze the constructs and items' reliability as well as the association among constructs. The results show that product quality features except extroversion have a positive and significant association with intention to purchase organic products in Vietnam. The results also reveal that customer satisfaction significantly and positively mediates among the associations of product quality features and intention to purchase organic products in Vietnam. This study is suitable for policymakers while formulating policies that may directly or indirectly affect customers' intention to purchase organic agricultural products.Luong Thu Thuy (Faculty of Economics, Academy of Finance, Vietnam), Tran Thi Phuong Diu (Faculty of Economics, Academy of Finance, Vietnam), Nguyen Dinh Hoan (Faculty of Economics, Academy of Finance, Vietnam), Vu Viet Ninh (Faculty of Economics, Academy of Finance, Vietnam), Nguyen Thi Thuy Nga (Faculty of Economics, Academy of Finance, Vietnam)Includes bibliographical reference

Impact of gut microbiome manipulation in 5xFAD mice on Alzheimer’s disease-like pathology

The gut brain axis seems to modulate various psychiatric and neurological disorders such as Alzheimer’s disease (AD). Growing evidence has led to the assumption that the gut microbiome might contribute to or even present the nucleus of origin for these diseases. In this regard, modifiers of the microbial composition might provide attractive new therapeutics. Aim of our study was to elucidate the effect of a rigorously changed gut microbiome on pathological hallmarks of AD. 5xFAD model mice were treated by antibiotics or probiotics (L. acidophilus and L. rhamnosus) for 14 weeks. Pathogenesis was measured by nest building capability and plaque deposition. The gut microbiome was affected as expected: antibiotics significantly reduced viable commensals, while probiotics transiently increased Lactobacillaceae. Nesting score, however, was only improved in antibiotics-treated mice. These animals additionally displayed reduced plaque load in the hippocampus. While various physiological parameters were not affected, blood sugar was reduced and serum glucagon level significantly elevated in the antibiotics-treated animals together with a reduction in the receptor for advanced glycation end products RAGE—the inward transporter of Aβ peptides of the brain. Assumedly, the beneficial effect of the antibiotics was based on their anti-diabetic potential

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

Influence of acetylcholine esterase inhibitors and memantine, clinically approved for Alzheimer’s dementia treatment, on intestinal properties of the mouse

Four drugs are currently approved for the treatment of Alzheimer’s disease (AD) by the FDA. Three of these drugs—donepezil, rivastigmine, and galantamine—belong to the class of acetylcholine esterase inhibitors. Memantine, a NMDA receptor antagonist, represents the fourth and a combination of donepezil and memantine the fifth treatment option. Recently, the gut and its habitants, its microbiome, came into focus of AD research and added another important factor to therapeutic considerations. While the first data provide evidence that AD patients might carry an altered microbiome, the influence of administered drugs on gut properties and commensals have been largely ignored so far. However, the occurrence of digestive side effects with these drugs and the knowledge that cholinergic transmission is crucial for several gut functions enforces the question if, and how, this medication influences the gastrointestinal system and its microbial stocking. Here, we investigated aspects such as microbial viability, colonic propulsion, and properties of enteric neurons, affected by assumed intestinal concentration of the four drugs using the mouse as a model organism. All ex vivo administered drugs revealed no direct effect on fecal bacteria viability and only a high dosage of memantine resulted in reduced biofilm formation of E. coli. Memantine was additionally the only compound that elevated calcium influx in enteric neurons, while all acetylcholine esterase inhibitors significantly reduced esterase activity in colonic tissue specimen and prolonged propulsion time. Both, acetylcholine esterase inhibitors and memantine, had no effect on general viability and neurite outgrowth of enteric neurons. In sum, our findings indicate that all AD symptomatic drugs have the potential to affect distinct intestinal functions and with this—directly or indirectly—microbial commensals

Effect of Graphene-Gold Nanocomposites on the Photocatalytic Activity Of TiO2_2

The synthesis of graphene (Gr) - gold (Au) nanoparticle (NP) composite was achieved using continuous ultraviolet wave exposure. The functional groups were investigated with FT-IR spectra. From the Raman spectra, D-band and G-band of graphene were identified. As a result, the uniform deposition of nanometer-sized Au NPs on the graphene sheets was observed from the field emission scanning electron microscope (FE-SEM) images. The photodegradation of methylene blue in aqueous solutions is studied using various photocatalysts, including neat TiO2, Gr/TiO2 and Gr-Au/TiO2 composites. The Gr weight ratio in this research is 2%. The Gr2%-Au0.1%/TiO2 composite had the highest photoactivity

Estimating Water Content and Grain Size of Intertidal Flat Sediments Using Visible to Shortwave-Infrared Reflectance and Sentinel 2A Data: A Case Study of the Red River Delta, Vietnam

Sediment properties such as water content (WC) and grain size (GS) are essential to characterize the environmental conditions of tidal flats. This article aimed to develop appropriate models to estimate the WC and GS of surface sediments for an intertidal flat on the Red river delta (Vietnam) using Sentinel 2A (S2A) images. The spectral reflectance, WC, and GS of 96 sub-samples from 12 sediment samples collected on December 17, 2017 were measured to clarify their relationships. The WC was highly correlated with the reflectance ratio of two shortwave-infrared bands, R(2190)/R(1610) (R² = 0.93). The median GS (D₅₀) at 0%, 15%, and 20% of WC was significantly correlated with the reflectance ratio of the near-infrared band (842 nm) versus the visible-green band (560 nm) (R² > 0.78). Next, D₅₀ was estimated from a multivariate regression model using this band ratio, the visible-red band (665 nm), and WC. The accuracy of the models was verified by comparisons with WC and D₅₀ from 20 samples collected on March 12th 2019 (RMSE of both WC and D₅₀ 30%) in very fine sediments (silts), which is consistent with other intertidal flats with similar sediment types. This article was limited to fine sediment samples. Therefore, our next step is to incorporate coarse sediments into the models to provide more universal mapping of WC and sediment types

EVALUATION OF BIODEGRADATION RATE CONSTANT (K₁) AND BOD POLLUTION IN THE LAKE SYSTEM OF HANOI

Joint Research on Environmental Science and Technology for the Eart

HIGH PROTECTION PERFORMANCE OF COATING SYSTEMS BASED ON ZINC RICH PRIMER AND FLUOROPOLYMER COATING

Coating systems based on zinc rich primer and fluoropolymer top coat were exposed for 8 years at different atmospheric stations in Vietnam: Hanoi, Ha Long and Nha Trang. For comparison the coating system with zinc rich primer and polyurethane topcoat was also tested. The degradations of coating systems were evaluated by gloss measurement and electrochemical impedance spectroscopy. The obtained results show that coating systems with zinc rich primer and top coatings based on fluoropolymer  and polyurethane topcoats show very high weather resistance and corrosion protection performance, but the systems with fluoropolymer are better than coating system with polyurethane topcoat

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