299 research outputs found
sj-docx-1-npx-10.1177_1934578X231214159 - Supplemental material for GC-MS Characterization, in Vitro Antioxidant and Anti-Inflammatory Activities of Essential oil from the Leaves of <i>Litsea balansae</i> Lecomte
No full textSupplemental material, sj-docx-1-npx-10.1177_1934578X231214159 for GC-MS Characterization, in Vitro Antioxidant and Anti-Inflammatory Activities of Essential oil from the Leaves of Litsea balansae Lecomte by Duc V. Ho, Hanh N. T. Hoang, Nguyen H. Nguyen, Hang B. Do, Hung Q. Vo, Anh T. Le, Thang Q. Le and Ty V. Pham in Natural Product Communications</p
Influence of coated surfaces and gap size on boiling heat transfer of deionized water
No full textNanocoating techniques have been used to increase the heat transfer coefficient by changing the surface morphology, which could potentially increase the heat transfer in pool boiling systems. The present study aims to determine the influence of nanocoated surfaces and the gap size on the heat transfer coefficient and the critical heat flux during the pool boiling of deionized water, at saturation temperature in atmospheric pressure. Tests were performed on a copper heating bare surface with an average roughness of 0.330 μm. The nanocoated surfaces were produced by alumina (Al2O3) nanoparticle deposition with 0.007% of volumetric concentration by using nanofluid boiling process. A gap size of 1.0 mm, corresponding to a Bond number equal to 0.4, was analyzed, and the results were compared with the cases without confinement. Concerning the heat transfer coefficient, the coated surface showed deterioration in the heat transfer performance (approximately 29%) as compared with the uncoated surface mainly due to the fouling resistance formed on the heating surface, confirmed by the surface characterization (SEM images). However, for coated surfaces and for confined cases, enhancement of 28% in the dryout heat flux was observed; the coating process significantly increases the surface wettability, which, in turn, increases the re-wetting capacity during the confined boiling process. Moreover, the heat transfer coefficient is more influenced by the gap size effect than the coating process. The chemical analysis showed that changes in the surface morphology occurred due to the effects of the confinement as compared to the original coated layer (the morphological aspect and melting mechanism were similar to the named liquid phase sintering).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Post-Graduation Program in Mechanical Engineering School of Engineering UNESP – São Paulo State University, Av. Brasil, 56Mechanical Engineering Department São Carlos School of Engineering USP - University of São Paulo, 400, Av. Trabalhador São CarlenseDivision of Computational Physics Institute for Computational Science Ton Duc Tang UniversityFaculty of Electrical and Electronics Engineering Ton Duc Thang UniversityPost-Graduation Program in Mechanical Engineering School of Engineering UNESP – São Paulo State University, Av. Brasil, 56FAPESP: 2013/15431-7FAPESP: 2019/02566-8CNPq: 458702/2014-
Do global sentiment shocks spillover towards emerging and frontier markets?
No full textThis study aims to investigate the impact of sentiment shocks based on US investor sentiments,
bearish and bullish market conditions. Earlier studies, though very few, only consider the effect of investor
sentiments on stock returns of emerging frontier Asian (EFA) markets. This study uses the application of regime switching model because of its capability to explore time-varying causality across different regimes unlike traditional linear models. The
Markov regime switching model uses regime switching probabilities for capturing the potential asymmetries
or non-linearity in a model, in this study’s case, thereby adjusting investor sentiments shocks to stock market
returns. The results of the Markov regime switching method suggests that US sentiment, bullish and
bearish market shocks act as a main contributors for inducing variation in EFA stock market returns. The
study’s non-parametric robustness results highlight an asymmetric relationship across the mean series,
whereas a symmetric relationship across variance series. The study also reports Thailand as the most sensitive
market to global sentiment shocks. The sensitivity of the EFA markets to these global sentiment shocks
highlights their sensitivity and implications for investors relying merely on returns correlation and spillover.
These findings also suggest that spillover from developed to emerging and frontier equity markets only in the
form of returns following traditional linear models may not be appropriate. This paper supports the behavioral aspect of investors and resultant spillover from developed market sentiments to emerging and frontier market returns across international equity markets offering more rational justification for an irrational behavior. The study’s motivation to use the application of regime switching models is because of its capability to explore time-varying causality across different regimes unlike traditional linear models. The Markov regime switching model uses regime switching probabilities for capturing the potential asymmetries or non-linearity in a model, in the study’s case, thereby adjusting investor sentiments shocks to stock market returns. It is also useful of the adjustment attributable to exogenous events
Do fiscal shocks explain bond yield in high- and low-debt economies?
No full textPurpose: The purpose of this study is to investigate how the uncertainty associated with fiscal policy, i.e. government expenditure and tax revenues, can affect the interest rates in a group of eleven countries, comprising high- and low-debt countries: Cyprus, Greece, Ireland, Italy, Portugal, Spain, Australia, Canada, Denmark, New Zealand and Norway.
Design/methodology/approach: The empirical analysis makes use of the structural VAR (SVAR) methodological approach, which allows us to decompose the effects of the contribution of shocks generated by each variable, as well as their transmission effects.
Findings: The empirical findings suggest that both demand and supply factors influence interest rates across their frequency spectrum. For the majority of high-debt countries, the course of the yields on their government bonds is driven mainly by supply side factors and not demand (i.e. government expenses or taxes) factors.
Research limitations/implications: Given that the economies of certain (mostly small) countries are affected by economic conditions in large countries, especially when they have large capital flows or trade much with these countries, the future empirical analysis could also consider both domestic and international (control) macroeconomic variables to explain the course of interest rates due to fiscal changes.
Originality/value: The previous literature does not capture the financial crisis period, nor does it take a comparative approach – high debt versus low debt – to investigate the effect of fiscal shocks on interest rates. Thus, we aim to respond to the following questions: (1) How do fiscal shocks affect interest rates in the sample of selected countries? (2) How different is the impact of fiscal shocks on interest rates in high- and low-debt countries
Establishment of a multiplex pcr assay for simultaneously detecting two target sequences of Chlamydia trachomatis
No full textPCR is a technique commonly applied in screening urogenital tract infections caused by Chlamydia trachomatis (CT). Since some CT strains might not have plasmid, the PCR technique using DNA plasmid sequence as target would produce false negative results. This study developed a multiplex PCR (mPCR) assay that could detect both DNA plasmid and omp1 gene sequences of CT in order to avoid these false negative results. Originally, 7 primer pairs were designed based on DNA plasmid and omp1 gene sequences of CT. After being tested in different conditions, two primer pairs CTM-F1R1 and CTP-F1R2 were finally selected to be used in the mPCR assay that could simultaneously detect specific sequences on DNA plasmid (434 bp) and on omp1 gene (153 bp). CT could be detected by mPCR if there were 5 or more copies of omp1 gene and/or 5 or more copies of plasmid in suspected samples. The assay was tested on 128 endocervical swab specimens and the results were then compared with those of 2 other PCR assays. Sensitivity, specificity, positive predictive value, negative predictive value of the mPCR assay were all 100%. Additionally, this assay could eliminate false negative results of CT strains which do not contain plasmids. Thus, the developed assay might be applied in diagnosis and/or screening CT in the community. Citation: Nguyen Nam Thang, Bui Duc Do, Nguyen Thi Hoa, Tran Thi Hoa, Phan Ngoc Quang, Bui Huong Dung, Dong Van Quyen, 2017. establishment of a multiplex pcr assay for simultaneously detecting two target sequences of Chlamydia trachomatis. Tap chi Sinh hoc, 39(1): 108-114. DOI: 10.15625/0866-7160/v39n1.8396. *Corresponding author: [email protected]. Received 21 September 2015, accepted 20 March 2017
Detection and monitoring of cancers with biosensors in Vietnam
No full textBiosensors are able to provide fast, accurate and reliable detec-tions and monitoring of cancer cells, as well as to determine the effectiveness of anticancer chemotherapy agents in cancer treatments. These have attracted a great attention of research communities, especially in the capabilities of detecting the path-ogens, viruses and cancer cells in narrow scale that the conven-tional apparatus and techniques do not have. This paper pre-sents technologies and applications of biosensors for detections of cancer cells and related diseases, with the focus on the cur-rent research and technology development about biosensors in Vietnam, a typical developing country with a very high number of patients diagnosed with cancers in recent years, but having a very low cancer survival rate. The role of biosensors in early detections of diseases, cancer screening, diagnosis and treat-ment, is more and more important; especially it is estimated that by 2020, 60-70% new cases of cancers and nearly 70% of cancer deaths will be in economically disadvantaged countries. The paper is also aimed to open channels for the potential R&D collaborations with partners in Vietnam in the areas of innovative design and development of biosensors in particular and medical technology devices in general
The impact of Basel standards on banks' lending activities: An empirical evidence from Vietnam in the beginning
No full textThis study aims to analyze how lending ability would be affected following the implementation of Basel's standards in Vietnamese commercial banks. I have selected panel data from first quarter 2011 to third quarter 2014 in Vietnam banking industry - the period of regulatory applied for this study and I find that beside the change of own capital which would have impact on lending capability at time of capital change, lending capability would also be directly influenced by borrowings from other banks and deposits of customers. Using multi - regression, LMG, DEA method and Granger - Cause test, I find that banks who fund their lending with less dependence on interbank capital are more efficient and could do business better than those who fund their lending mostly by interbank capital. Furthermore, almost elements that fund for the lending do not support for the improvement of banks' capital
Prediction of development length from free-end slip in pretensioned concrete members
No full text[EN] Development length of prestressing strands is a significant parameter in the design of pretensioned concrete members.
The adequacy of the code equations used to predict the development length needs to be verified when a new
material or design parameter is introduced for precast, prestressed concrete applications. This study develops a simple
and reliable technique to quantify the development length based on the premise of the slip theory, which proposes
the free-end slip (FES) as an indicator of the development length. Twenty-five pretensioned concrete beams were cast
with 15 mm diameter strands. FES was measured at both beam ends at prestress transfer. Development length was
determined by performing bending tests at different embedment lengths. The experimental results were synthesised
to revise the slip theory. The applicability of the revised-slip theory was validated by collected experimental data
of pretensioned concrete members using various types of concrete, strand diameters and release techniques.The authors would like to acknowledge the financial and technical support of the Arkansas State Highway and Transportation Department (AHTD), Mack-Blackwell Rural Transportation Center (MBTC) and Ton Duc Thang University. The contents of this paper reflect the views of the authors, and do not necessarily reflect the views of the research sponsors.Dang, CN.; Floyd, RW.; Hale, WM.; Martí Vargas, JR. (2018). Prediction of development length from free-end slip in pretensioned concrete members. Magazine of Concrete Research. 70(14):714-725. https://doi.org/10.1680/jmacr.17.00334S714725701
Safe haven for Asian equity markets during financial distress: Bitcoin versus Gold
No full textThis study aims to analyse the role of bitcoin and gold as safe haven assets for Asian equity markets during periods of high market uncertainty related to the global COVID-19 pandemic, high volatility and extreme stock market conditions. Our empirical analysis employs the DCC-GARCH methodology to estimate the time-varying relationship between bitcoin/gold and the Asian stock market from 2016 to 2023. Our findings reveal that bitcoin serves as a strong hedge for Taiwan and Pakistan, whereas gold can be considered a strong hedge for Japan, Singapore, India, Thailand and Vietnam. Interestingly, we observe that bitcoin does not exhibit safe haven properties in any of the Asian countries observed. In contrast, gold demonstrates strong safe haven abilities for Singapore, India and Thailand. These results remain consistent across various measures of market turmoil, including the volatility index, COVID-19-related periods and low quantiles on the stock market. Furthermore, our results suggest that the perception and adoption of gold as a safe haven asset in Japan and Vietnam is mainly influenced by global events and uncertainties, rather than localized stock market conditions. These findings offer valuable information for investors, financial institutions as well as policy makers and regulators as to how cryptocurrency and gold have evolved as hedge and safe haven assets in Asia during uncertainty periods.Ton Duc Thang UniversityTon Duc Thang University [FOSTECT.2023.18
Cost-effective solutions and tools for medical image processing and design of personalised cranioplasty implants
No full textCranial defects which are caused by bone tumors or traffic accidents are treated by cranioplasty techniques. Cranioplasty implants are required to protect the underlying brain, correct major aesthetic deformities, or both. With the rapid develop-ment of computer graphics, medical image processing (MIP) and manufacturing technologies in recent decades, nowadays, personalised cranioplasty implants can be designed and made to improve the quality of cranial defect treatments. However, software tools for MIP and 3D modelling of implants are ex-pensive; and they normally require high technical skills. Espe-cially, the process of design and development of personalised cranioplasty implants normally requires a multidisciplinary team, including experts in MIP, 3D design and modelling, and Biomedical Engineering; this leads to challenges and difficulties for technology transfers and implementations in hospitals. This research is aimed at developing, in particular, cost-effective solutions and tools for design and modeling of per-sonalised cranioplasty implants, and to simplify the design and modelling of implants, as well as to reduce the design and modeling time. In this way, surgeons and engineers can con-veniently and easily design personalised cranioplasty implants, without the need of using complex MIP and CAD tools; and as a result the cost of implants will be minimised
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