ADSORPTION OF MERCURIC ION FROM AQUEOUS SOLUTIONS USING MODIFIED FLY ASH

In this study, fly ash was treated with NaOH solution (FAN) before modifying with (3-mercaptopropyl) triethoxysilane - MPTMS (FAMPS). By using FTIR, FESEM, XRD, EDX, and BET techniques, the change in structure, composition and morphology of FAN and FAMPS was evaluated. The FTIR spectra of FAN and FAMPS showed that there is no chemical reaction between the MPTMS and FAN. After modification, the FAMPS has a rough surface with composition difference from the FAN. Mercuric ion adsorption behavior as well as adsorptionisotherm models (Langmuir and Freundlich) of the FAN and FAMPS were also investigated and discussed. Thanks to FAN modification, the mercuric ion removal percent of the FAMPS was higher than that of the FAN. Owing to the adsorption data, Freundlich isotherm modelwas fitted for the mercuric ion adsorption process

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

Determinants Influencing Tax Audit Services: The Case of Vietnam

Unlike former researches on tax audit activities in Vietnam which often use qualitative method to analyze and give recommendations, this research uses quantitative method to identify and verify determinants influencing tax audit activities, by assessing reliability and suitability of measuring scales; verifying research model and research hypothesis; determining impact levels of different drivers of tax audit activities (regarding tax audit conclusions) over 268 tax auditors through questionnaires. The research results are recommendations for Vietnamese tax authorities to consider enhancing the supervision of tax audit activities; build a database to serve tax audit activities and restructure procedures, finalize tax audit methods to increase tax audit performance. Keywords: tax audit, tax audit conclusions, drivers, audit supervision, audit process, database about taxpayers

Evaluating the Ability to Achieve Efficiency in Providing Services of the Freight Forwarding Firms in Viet Nam

In recent years, Vietnam freight forwarding industry is growing and contributing significantly to the national GDP. However, the efficiency in providing service delivery at the domestic firms is not high to compete with multinational companies that are strong potential and finance. There have been many studies on freight forwarding, but mainly qualitative research and other studies are in-depth analysis logistics. This research presents the factors that affect efficiency in providing services. This research has been used factor analysis method and binary regression model (Binary Logistics) and identified 4 factors that affect the efficiency in providing service of freight forwarding firms: (1) Resources of business (2) Outcomes (3) The quality of staffs (4) The relationship between enterprises and their customers, and outcomes is the factor provided the highest positive correlation to the ability to achieve efficiency in providing services of freight forwarding firms.Binary Logistic model showed the probability of business efficiency is 72.5%. Thus, at the level of resources to provide services is 3.35, the outcome is 3.66, quality of the staffs is 3.59 and the relationship with customers is 3.40, shows that enterprises operate efficiently. Value prediction accuracy of the model is 93.3%

Using fly ash treated by NaOH and H2SO4 solutions for Hg2+ and Cd2+ ion adsorption.

This paper presents the results of adsorption ability of heavy metal ions (Hg2+ and Cd2+) by fly ash (FA) before and after treatment using NaOH and H2SO4 solutions.  Original- and treated FA were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). Specific surface area of FA before and after treatment was calculated by Brunauer – Emmett – Teller (BET) isotherm equation. The obtained results indicated that the morphology and specific surface area of FA changed clearly after treatment by acid or alkaline solutions. Adsorption capacity the Hg2+ and Cd2+ ion by FA was determined from data of UV-Vis spectra. After treatment, the adsorption capacity of ions by FA increased remarkably in comparison with non-treated FA. The FA treated by NaOH solution has the adsorption capacity higher than FA treated by H2SO4 solution. The maximum adsorption capacity of the FA treated by NaOH solution for Cd2+ and Hg2+ ions at room temperature is 28.97 and 14.60 mg/g, respectively. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. The results showed that equilibrium data were fitted well to the Langmuir isotherm. Keywords. Fly ash, treatment, adsorption capacity, heavy metal, Langmuir isotherm

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

Higgs Mass Constraint on a Low Scale SUSY Model

Randal-Sundrum models have an interesting feature that an effective physical scale can be generated from a much larger one of the underlying theory. In this paper, we investigate a model of supersymmetry in the Randall-Sundrum spacetime with a low cutoff scale. Due to the warp factor, the Kaluza-Klein scale is warped down to $\mathcal{O}$(100) TeV. With the MSSM superfields living in the bulk, the soft SUSY breaking terms of the 4D effective theory are derived from the original 5D Lagrangian by integrating out the extra-dimension. We examine the constraint of the Higgs boson mass measurement on the model. As a result, the viable parameter space with the ability to reproduce a 125 GeV Higgs mass is identified. The constraint rules out parameter regions with the stop masses larger than 20 TeV. Therefore, the parameter space of the model can be explored in a future 100 TeV collider

‘The painting can be fake, but not the feeling’: an overview of the Vietnamese market through the lens of fake, forgery and copy paintings

A work of Vietnamese art crossed a million-dollar mark in the international art market in early 2017. The event was reluctantly seen as a sign of maturity from the Vietnamese art amidst the many existing problems. Even though the Vietnamese media has discussed the issues enthusiastically, there is a lack of literature from the Vietnamese academics examining the subject, and even rarer in from the market perspective. This paper aims to contribute an insightful perspective on the Vietnamese art market, and hesitantly the Vietnamese art as well, through the lens of fake, forgery and copy artworks. 35 cases of fake, forgery and copy paintings were found on the news and from the experts' wisdom. Through the examples, we argue that the Vietnamese art market is a temporary reaction to the immaturely rising of the Vietnamese art and the economy. Therefore, the art market is unable to function healthily unless the Vietnamese art and the economy developed

PREPARATION AND FTIR STUDIES OF PMMA/PVC POLYMER BLENDS, PVC-g-PMMA GRAFT COPOLYMERS AND EVALUATING GRAFT CONTENT

This study presents the qualitative and quantitative analyses of Fourier Transform Infrared (FTIR) spectra of poly(methyl methacrylate)/poly(vinyl chloride) blends (PMMA/PVC), as well as PVC-g-PMMA graft copolymers. Graft copolymerizations of methyl mathacrylate (MMA) onto PVC macromolecules were carried out mixture of cyclohexanone/N,N-dimethylformamide as solvents, dibenzoyl peroxide as initiator and nitrogen medium. FTIR spectra of PMMA/PVC blends showed that there were molecular interactions between C=O groups of PMMA and C-Cl groups of PVC. Assignments of infrared absorption bands for specific groups of PMMA/PVC blends have been contributed. Using regression method, linear calibration curve between PMMA mole content and peak areas of C=O groups in FTIR spectra of the blends has been found when C=O peak areas were multiplied by an appropriate factor. PMMA grafted content and total PMMA formed content in PVC-g-PMMA graft copolymers have been evaluated. The results showed that grafted PMMA content was increased since PVC was initiatly dechlorinated by NaOH solution. The grafted PMMA content and total formed PMMA content were 5.05 wt.% and 11.25 wt.% respectively when MMA monomers were grafted onto neat PVC and modified PVC molecules

Prevalence of Marek’s disease virus in unvaccinated healthy backyard chickens in Cantho city, Vietnam and genetic characterization of meq gene

An investigation was carried out to survey the prevalence of Marek’s disease virus serotype 1 (MDV-1) on unvaccinated healthy backyard chicken flocks from four districts in Cantho city and to analyze the genetic characterization of the meq gene. A total of 353 feather follicle samples were collected from 50 unvaccinated chicken flocks for Marek’s disease to investigate prevalent MDV-1 by polymerase chain reaction (PCR). The four represent strains were chosen for meq gene sequencing. The results revealed that 26 out of 353 samples were positive for MDV-1 accounting for 7.37%. There were significant differences in the prevalence of MDV-1 on chickens among districts (P<0.05). The Meq protein of the four strains (VT, CD, PD, and TL) contained 20.14% proline and three regions of proline repeats. Besides, all four strains occurred with amino acid point mutations. These strains had only a substitution of proline at position 217 as well as interruption of consecutive proline at site 2. Phylogenetic analysis indicated that these strains were within a group relating to virulent Italian isolates