227 research outputs found

    CeO2 based catalysts for the treatment of propylene in motorcycle's exhaust gases

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    In this work, the catalytic activities of several single metallic oxides were studied for the treatment of propylene, a component in motorcycles' exhaust gases, under oxygen deficient conditions. Amongst them, CeO2 is one of the materials that exhibit the highest activity for the oxidation of C3H6. Therefore, several mixtures of CeO2 with other oxides (SnO2, ZrO2, Co3O4) were tested to investigate the changes in catalytic activity (both propylene conversion and CO2 selectivity). Ce0.9Zr0.1O2, Ce0.8Zr0.2O2 solid solutions and the mixtures of CeO2 and Co3O4 was shown to exhibit the highest propylene conversion and CO2 selectivity. They also exhibited good activities when tested under oxygen sufficient and excess conditions and with the presence of co-existing gases (CO, H2O)

    Uloga osobina ličnosti u oblikovanju poduzetničke namjere: Komparativna studija Južne Koreje i Vijetnama

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    This paper investigates the role of personality traits in nurturing entrepreneurial intention in South Korea and Vietnam. We developed a research model to examine the integrated influence of both positive entrepreneurial characteristics and dark triad on entrepreneurial intention in South Korea and Vietnam. Primary data was collected from 550 students in South Korea and 700 students in Vietnam using the convenient sampling method in a self-administered questionnaire survey. We used structural equation modelling (SEM) to analyse structural relationships between positive entrepreneurial attributes, dark triads, and entrepreneurial intention in two samples. T-tests were also performed to explore any differences in students’ entrepreneurial intention in South Korea and Vietnam regarding their family background and gender. Findings showed that positive entrepreneurial attributes and dark triads influence entrepreneurial intention differently in the two countries. While the dark triad mainly influenced Vietnamese students’ intention to startup, Korean students received more impact from the positive entrepreneurial characteristics such as risk tolerance, locus of control, and entrepreneurial alertness. Surprisingly, both gender and family tradition do not affect students’ entrepreneurial intention. Based on our findings, we suggested that policymakers and higher education institutions in both South Korea and Vietnam promote students’ entrepreneurial intentions in the future.Ovaj rad istražuje ulogu osobina ličnosti u njegovanju poduzetničkih namjera u Južnoj Koreji i Vijetnamu. Razvili smo znanstveni model za ispitivanje integriranog utjecaja pozitivnih poduzetničkih karakteristika kao i utjecaj mračne trijade na poduzetničke namjere u Južnoj Koreji i Vijetnamu. Primarni podaci dobiveni anketiranjem 550 studenata u Južnoj Koreji i 700 studenata u Vijetnamu prikupljeni su korištenjem prikladne metode uzorkovanja u anketi koju su sami proveli. Koristili smo modeliranje strukturnim jednadžbama (SEM) za analizu strukturnih odnosa između pozitivnih poduzetničkih atributa, tamnih trijada i poduzetničke namjere u dva uzorka. Također su provedeni T-testovi kako bi se istražile razlike u poduzetničkim namjerama studenata u Južnoj Koreji i Vijetnamu s obzirom na njihovo obiteljsko porijeklo i spol. Rezultati su pokazali da pozitivne poduzetničke osobine i mračne trijade različito utječu na poduzetničke namjere u dvije zemlje. Dok je mračna trijada uglavnom utjecala na namjeru vijetnamskih studenata da se pokrenu, korejski studenti dobili su veći utjecaj od pozitivnih poduzetničkih karakteristika kao što su tolerancija na rizik, lokus kontrole i poduzetničke budnosti. Iznenađujuće, spol i obiteljska tradicija ne utječu na poduzetničke namjere studenata. Na temelju naših otkrića, predložili smo da kreatori politika i visokoškolske ustanove u Južnoj Koreji i Vijetnamu promiču poduzetničke namjere studenata u budućnosti

    Level of Determinants Impact on Buyer’s Purchasing Intention in Motor Liability Insurance: Case of Vietnam

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    Motor liability insurance has been included in the compulsory insurance category that each vehicle owner of every type of motor vehicle must participate in in Vietnam. However, in fact, the participation in this type of insurance is not popular and not strictly managed. This paper presents an approach to modeling and analyzing the possible determinants that may affect the intention to buy motor liability insurance for motor vehicle owners in the North of Vietnam. The target audience of this study is motorcycle owners. Based on the theories of buying intention, buying behavior and the specific characteristics of this insurance, this study has proposed a model with 4 factors influencing intention to participate in the insurance: Attitudes towards risk and insurance, subjective standards, Insurance Perceptions, and Product Accessibility. Taken together, these factors model a consumer's tendency toward insurance intentions for motorbike owners. The results show that all of the above factors have influence on the intention of motorcycle owners to participate in insurance. Keywords: Motor liability insurance, Buying intention, Purchase decision DOI: 10.7176/EJBM/13-8-11 Publication date: April 30th 202

    Contribution of health workforce to health outcomes: empirical evidence from Vietnam.

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    BACKGROUND: In Vietnam, a lower-middle income country, while the overall skill- and knowledge-based quality of health workforce is improving, health workers are disproportionately distributed across different economic regions. A similar trend appears to be in relation to health outcomes between those regions. It is unclear, however, whether there is any relationship between the distribution of health workers and the achievement of health outcomes in the context of Vietnam. This study examines the statistical relationship between the availability of health workers and health outcomes across the different economic regions in Vietnam. METHODS: We constructed a panel data of six economic regions covering 8 years (2006-2013) and used principal components analysis regressions to estimate the impact of health workforce on health outcomes. The dependent variables representing the outcomes included life expectancy at birth, infant mortality, and under-five mortality rates. Besides the health workforce as our target explanatory variable, we also controlled for key demographic factors including regional income per capita, poverty rate, illiteracy rate, and population density. RESULTS: The numbers of doctors, nurses, midwives, and pharmacists have been rising in the country over the last decade. However, there are notable differences across the different categories. For example, while the numbers of nurses increased considerably between 2006 and 2013, the number of pharmacists slightly decreased between 2011 and 2013. We found statistically significant evidence of the impact of density of doctors, nurses, midwives, and pharmacists on improvement to life expectancy and reduction of infant and under-five mortality rates. CONCLUSIONS: Availability of different categories of health workforce can positively contribute to improvements in health outcomes and ultimately extend the life expectancy of populations. Therefore, increasing investment into more equitable distribution of four main categories of health workforce (doctors, nurses, midwives, and pharmacists) can be an important strategy for improving health outcomes in Vietnam and other similar contexts. Future interventions will also need to consider an integrated approach, building on the link between the health and the development

    Co3O4 catalysts on CeO2-ZrO2 supports and Co3O4-CeO2 catalysts on Al2O3/SiO2 supports for the oxidation of propylene

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    Different compositions of Co3O4 catalysts on CeO2-ZrO2 solid solution (Ce0.9Zr0.1O2 and Ce0.8Zr0.2O2) have been studied for the oxidation of propylene. The optional amount of Co3O4 active phase on CeO2-ZrO2 support of 30 wt% was found. The mixed Co3O4-CeO2-ZrO2 with the same composition of the optimal supported ones showed approximately the same activity, which was not higher than the activity of the mixed Co3O4-CeO2 catalyst. Catalytic activities of mixed Co3O4-CeO2 with different loading contents supported on high surface area supports (Al2O3, SiO2) were then measured. The optimal composition of active phase was still 30 wt% but the minimum temperature of the highest activity increased to above 300 degrees C due to the inert nature influence of the support

    Osteogenesis activity of fractions extracted from Clinacanthus nutans (Burm. F.) Lindau

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    Osteogenesis activity of fractions extracted from Clinacanthus nutans was evaluated on an in vitro model using osteoblast MC3T3-E1 cells. The results showed that all fractions, including ethanol (EtOH), n-hexane, ethyl acetate (EtOAc) and butanol (BuOH) were not significantly toxic to the osteoblast cells at the test concentrations of 5, 10, 25, and 50 µg/mL. The EtOH and EtOAc fractions exhibited the highest osteogenesis activity in terms of enhancement of alkaline phosphatase (ALP) and mineralization activity of MC3T3-E1 cells, especially the EtOAc fraction which increased ALP activity up to 30% and mineralization activity up to 100%. Thus, the EtOAc fraction shows osteogenesis activity through stimulating activites of the two markers for bone generation including ALP and mineralization in osteoblast cells. The fraction is now under extensive investigation to isolate and fully understand the modes of action of the active compounds. 

    STUDY OF NEGATIVE REFRACTIVE INDEX IN Rb FOUR-LEVEL N-TYPE ATOMIC GAS MEDIUM

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    In this work, we study the generation of a negative refractive index based on electromagnetically induced transparency (EIT) in a Rb four-level N-type atomic gas medium. We derive analytic expressions for the relative permittivity and relative permeability of the medium according to the parameters of the probe, pump, and signal laser fields. We then investigate the variation of the real parts of the relative permittivity and relative permeability with respect to the intensity and frequency of the pump and signal laser fields. In the presence of the pump laser beam, the medium becomes transparent to the probe laser beam even in the resonant region. At the same time, the real parts of the relative permittivity and relative permeability are simultaneously negative (i.e., the medium exhibits a negative refractive index) in the EIT spectral domain. In the presence of the signal laser beam, the EIT effect occurs over two different frequency domains of the probe beam, so a negative refractive index is also generated in these two frequency domains. The investigation of the real parts of the relative permittivity and relative permeability with intensity and frequency of the pump and signal laser fields allowed us to find the laser parameters for the appearance of the negative refractive index, which can be useful for experimental observations

    Self-adaptive Controllers for Renewable Energy Communities Based on Transformer Loading Estimation

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    In this paper, self-adaptive controllers for renewable energy communities based on data-driven approach are proposed to mitigate the voltage rise and transformer congestion at the community level. In the proposed approach, the transformer loading percentage is estimated by the trained data-driven model, which uses the extreme gradient boosting regression algorithm based on a measurement set acquired from critical coupling points of the communities. To avoid voltage rise issues, the droop control parameters (i.e., voltage threshold for P - V, Q - V curves) are adaptively tuned based on the solar irradiance availability and estimated transformer loading. The proposed approach has been tested in the IEEE European LV distribution network. Results showed that the control approach could effectively reduce 22.2 % of the total overloaded instances, while still keeping voltage magnitude in the operation range. This method can help DSOs manage voltage violation and congestion without further communication

    Učinci zelene prakse restorana na namjeru kupca da kupe ekološki prihvatljive proizvode: Dokazi iz Vijetnama

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    This research aims to identify how green practices affect customer intention to purchase green products via customers’ emotional attachment. Using the PLS-SEM to analyze 358 restaurant guests to find customer intention to purchase green products is a fundamental constituent of a restaurant’s success. The results reveal that the application of recycling and composting, energy and water management activities have a positive significant impact on customer intention to purchase green products and pro-environmental emotional attachment, and the application of organic food-green products and materials have a significant impact on emotional attachment, but not trigger on customer intention to purchase green products. Meanwhile, the application of eco-friendly supplies did not affect emotional attachment and customer intention to purchase. Pro-environmental emotional attachment is a key mediator of the customer intention model. The results provided both knowledge and theory of green practices by adding customers\u27 emotional attachment into the theory of planned behavior to understand customer behavior toward green restaurants. It proposes managerial recommendations and building strategies for the long term to increase customer intention to purchase green products in the restaurant industry.Cilj je ovog istraživanja utvrditi način na koji zelene prakse utječu na namjeru kupca da kupi ekološke proizvode putem emocionalne povezanosti kupaca. Korištenje PLS-SEM-a za analizu gostiju iz 358 restorana kako bi se utvrdila namjera kupca da kupi ekološke proizvode temeljni je dio uspjeha restorana. Rezultati istraživanja upućuju na to da primjena recikliranja i kompostiranja, aktivnosti gospodarenja energijom i vodama imaju pozitivan utjecaj na namjeru kupca da kupi zelene proizvode i pro-ekološku emocionalnu privrženost te da primjena organske hrane –zelenih proizvoda i materijala na ekološku proizvodnju imaju značajan utjecaj na emocionalnu privrženost, ali ne i na namjeru kupca da kupi zelene proizvode. U međuvremenu, primjena ekološki prihvatljivih zaliha nije utjecala na emocionalnu privrženost i namjeru kupaca za kupnjom. Emocionalna vezanost za zaštitu okoliša ključni je posrednik modela namjere kupaca.Rezultati su osigurali i znanje i teoriju zelene prakse dodajući emocionalnu privrženost kupaca teoriji o planiranom ponašanju kako bi se razumjelo ponašanje kupaca prema zelenim restoranima. Predlažu se menadžerske preporuke i strategije izgradnje za dugoročno povećanje namjere kupca da kupi zelene proizvode u ugostiteljstvu

    The experience of using e-commerce platforms affects the online purchase intention of customers in the FMCG (Fast moving consumer goods) sector in Hanoi city

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    In recent times, the Vietnamese e-commerce market is in a period of strong development, in addition, to the sharp increase in people’s demands to join e-commerce platforms after the epidemic. The research group started with an overview study, then research hypotheses and models were proposed. After conducting preliminary qualitative and quantitative research to adjust the appropriate scales, the research group created a questionnaire and collected data in online forms with a sample size of 350. Next, the data was entered into the software for SEM analysis. The results of the study indicate that the quality of the e-commerce platform has an indirect impact on the purchase intention through the positive impact on the trust and the negative impact on the perceived risk. Attitudes towards information, trust, perceived risk, and perceived usefulness have direct influences on purchase intention. Attitude towards information, trust, and perceived usefulness have positive effects on purchase intention, while perceived risk harms purchase intention. In addition, purchase intention is relatively strongly influenced by trust and perceived usefulness. Perceived risk and attitude towards information have little influence on purchase intention. Finally, the research team proposes some solutions for businesses to increase the purchase intention of consumers through e-commerce platforms. &nbsp
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