A STUDY ON PHYSICO-MECHANICAL AND ANTICORROSIVE PROPERTIES OF CHEMICALLY MODIFIED GRAPHENE-BASED EPOXY NANOCOMPOSITE COATINGS

The use of coatings of functionalized nanostructured carbon based composite to inhibit corrosion is an area getting much of attention among scientists and industrialists. Lately, Graphene has started to play an important role in many applications. Graphene possesses excellent mechanical and thermal stability, low chemical reactivity, impermeability to most of gases, and high transparency. Thanks to these properties, Graphene is so far finding some applications for protective coatings. However, Graphene is apolar and nanostructured, so that is difficult to be dispersed into polar polymers as epoxy resin. In this paper, results of using chemically modified Graphene to reinforce the physico-mechanical properties and corrosive resistance properties of the epoxy paint coating are presented. Graphene was modified by oxidative method with mixtures of H2SO4, H3PO4 and KmnO4 solutions. The properties of obtained products were characterized by somephysico-chemical methods such as Fourier transformed Infrared Spectroscopy (FTIR), X-ray diffraction (XRD). The physico-mechanical and anti-corrosion properties of paints based on chemically modified Graphene-epoxy nanocomposite have been exceptionally superior to that of paints based on epoxy and Graphene

THE EFFECT OF NANOCARBON MATERIALS STRUCTURES ON THE PERFOMANCES OF EPOXY-BASED PAINT COATING FOR STEEL SURFACES

This paper reports the effect of the nanocarbon materials addition on the physico-mechanical properties and corrosion protective ability of epoxy based paint coatings for the steel surfaces. In this work the nanotubes and nanosheets (layers) structures of nanocarbon materials were used for the investigation. The properties of received products were measured by the test techniques for paint coating characterization. The results showed that the addition of the nanocarbon materials (only ratio of 0.1 wt%) significantly improved the physico-mechanical performance and corrosion protection ability of epoxy coatings for steel surfaces. However improvement quantity depends on the structure of nanocarbon materials. The obtained results showed that the nanosheets structure of carbons coatings made the physico-mechanical properties of the epoxy coating increased better than those of nanotube structure.

The Impact of Public Government on the Relationship Between Consumer Confidence and Stock Market Index: A Study

Purpose:  The article aims to study the impact of public governance on the relationship between consumer confidence and the stock market index.   Theoretical framework: The concept of consumer confidence index: According to consumer confidence, and stock market index is a way to measure expected changes in income. Katona also argues that consumer trust includes emotional and intellectual factors.   Design/methodology/approach: Data is collected from 2012 to 2021 from 10 middle-income countries. The public governance variable is measured by 6 component variables, including (1) Voice and accountability, (2) Political stability, (3) Government efficiency, (4) Regulatory quality, (5) the rule of law, and (6) Control of corruption. Consumer confidence is measured by the consumer confidence index (CCI) and the stock market index (SMI). The authors use P. VAR model to solve the set goal.   Findings: The research results show that public governance positively affects the relationship between consumer confidence and the stock market price index in high-middle-income countries. In contrast, public administration does not influence the relationship between consumer confidence and the stock market index in low-income countries.   Research, Practical & Social implications: Based on the research results, the authors propose policy implications for middle-income countries for investors' confidence and investment activities on the stock market, contributing to boosting capital in the future more efficient circular economy.   Originality/value: Government must increase its accountability to the people and investors for all activities and decisions of the Government. Creating a stable political environment, prioritizing dispute settlement by peaceful negotiations

Digital Transformation of the Banking Industry in Developing Countries

Purpose:  The study's objective is to test the impact of digital transactions on banking performance. Based on the previous research and the actual situations, it has been recognized that the critical role of digital banking is in developing the banking industry, especially in developing countries.   Theoretical framework:  In the next section, the study presents background information to promote the research. The digital transformation has changed how customers use financial services. This has pushed banks to adapt more quickly to the wave of digital transformation if they don't want to lose their valuable customer base.   Design/methodology/approach:  the methodology applied uses POOL, FEM, REM, and FGLS models to examine the impact of banking transactions made by digital technology on the bank's deposit and lending revenue. This article studies banking operations on digital platforms from 2012 to 2019 in developing countries.   Findings: The article's findings showed that digital banks' flexible products and services bring many benefits with a high level of interaction, such as supporting the relationship between customers and banks and improving operating revenue.   Research, Practical & Social implications: Practical implications enhanced the development potential of digital banking is relatively large, stemming from the market demand development orientation of the banking industry.   Originality/value: The paper's originality and value help banks invest in digital technology as the way forward to better serve their customers

SOCIAL SECURITY CONTRIBUTION INDEBTED FIRMS IN VIETNAM: CHARACTERISTICS AND MARKET VALUE

Abstract: This research is the first to empirically analyse the characteristics of firms that defer the social security contribution for their employees to the Vietnam Social Security agency, which is a chargeable offense starting 2018 as the Vietnam government focuses on ensuring worker welfare. Using data on 873 public firms headquartered in four major cities (Ha Noi, Ho Chi Minh, Da Nang, and Hai Phong), we find that non-state-owned firms and firms with lower profitability and higher debts are more likely to be in arrears on social security contribution. On the other hand, the roles of foreign ownership, size, number of employees, and number of branches/offices are insignificant. We further show that being social security contribution indebted would negatively affect shareholders’ interest as it is associated with lower firm market values.Key words: social security contribution, worker welfare, state ownership, foreign ownership, firm market valu

Mergers, Acquisitions and Market Concentration in the Banking Sector: The Case of Vietnam

Following the global trend, Vietnam also started opening up its economy and domestic reforms in 1986 and implemented a number domestic market reforms including in the banking and finance system. The merger and acquisitions (M&A) of banks have been a main component of the reform process. There have not been serious attempts to evaluate the M&A process and its impacts on the banking industry in a systematic way. The main purpose of this study is to fill that literature gap by providing a historical narrative of the M&A activities in Vietnam’s banking industry and analyzing its impacts on the system and market structure via quantitative and qualitative approaches, particularly using concentration indices

Phoebe Framework and Experimental Results for Estimating Fetal Age and Weight

Fetal age and weight estimation plays an important role in pregnant treatments. There are many estimation formulas created by the combination of statistics and obstetrics. However, such formulas give optimal estimation if and only if they are applied into specified community. This research proposes a so-called Phoebe framework that supports physicians and scientists to find out most accurate formulas with regard to the community where scientists do their research. The built-in algorithm of Phoebe framework uses statistical regression technique for fetal age and weight estimation based on fetal ultrasound measures such as bi-parietal diameter, head circumference, abdominal circumference, fetal length, arm volume, and thigh volume. This algorithm is based on heuristic assumptions, which aim to produce good estimation formulas as fast as possible. From experimental results, the framework produces optimal formulas with high adequacy and accuracy. Moreover, the framework gives facilities to physicians and scientists for exploiting useful statistical information under pregnant data. Phoebe framework is a computer software available at http://phoebe.locnguyen.net

Colostrum quality, intestinal microbiota and implications for health in young dairy calves

The early life of calves in southern Vietnam and in Sweden were studied in this thesis, with the focus on colostrum quality, gut microbial communities and antimicrobialresistant Escherichia coli. The first of four studies showed that most cows on smallholder farms in Vietnam produced colostrum of good quality and that only around 10% of calves suffered from failure of passive immune transfer. In a second study, bacterial communities in colostrum and in calf faeces samples collected at birth and at 14 days of age were identified by terminal restriction fragment length polymorphism (T-RFLP). The results showed that the microbial communities in colostrum and faeces differed in composition, with greater similarities in composition between colostrum and faeces from newborn calves than faeces from 14-day-old calves. Microbial composition also differed significantly between faeces from newborn and 14-day-old calves. Sequencing of 16S rRNA gene amplicons from a subset of faeces samples from healthy calves and calves treated for diarrhoea with antimicrobial drugs revealed significant differences between the groups, with higher relative abundances of Faecalibacterium and Butyricicoccus in healthy calves. In a third study, bacterial composition in intestinal contents and in mucosal scrapings collected from various gut segments in two- and seven-day-old calves was characterized by sequencing 16S rRNA gene amplicons using Illumina MiSeq. It was found that microbial community composition was associated with intestinal segment, with major differences in composition between proximal and distal parts of the gastrointestinal tract. However, microbial composition showed high similarity for segments in close proximity within the gut. Lactobacillus was present in quite high levels in the abomasum and duodenum, whereas Escherichia were more associated with the ileum, caecum, colon and faeces. Microbial composition and diversity altered with age and, although the microbiota in mucosa and gut content remained similar in general, certain microbial groups dominated in either mucosa or gut content. The fourth study revealed high levels of multidrug-resistance in Escherichia coli isolated from Vietnamese calves (53% of isolates tested), with blacCTM-M-1 (2 isolates), blacCTM-M-9 (1 isolate) and blacCMY-2 (1 isolate) being the main β-lactamase resistance groups detected. There was a high incidence of plasmid-mediated quinolone resistance (PMQR) genes in the E. coli isolates (21%). Overall, these results suggest that colostrum feeding and health are key factors affecting gut microbial community in the early life of dairy calves, but that antimicrobial resistance is an emerging problem on smallholder dairy farms in Vietnam