621 research outputs found
RELATIONSHIP BETWEEN EROSION AND ACCUMULATION OF SEDIMENTS IN COASTAL ZONE OF BINH THUAN PROVINCE-SOUTH CENTRAL OF VIETNAM
Joint Research on Environmental Science and Technology for the Eart
Insights into the magnetic origin of CunCr (n= 9÷11) clusters: A superposition of magnetic and electronic shells
Interests in Cu-Cr sub-nanometer systems have been increasing due to the recently-found icosahedral Cu12Cr cluster as a superatomic molecule, where the 3d-Cr and 4s-Cu electrons can phenomenologically form the 18-e molecular shell (1S21P61D10) of Cu12Cr. In this report, we set out to investigate the energetically-preferred geometries and stabilities of CunCr (n = 9÷11) clusters using the density-functional-theory calculations. It is found that not all of 3d-Cr electrons involve in the formation of the cluster shell and the remaining localized ones cause the magnetic moment of the clusters, which is different from what was believed
Reaching high accuracy for energetic properties at second-order perturbation cost by merging self-consistency and spin-opposite scaling
Quantum chemical methods dealing with challenging systems while retaining low
computational costs have attracted attention. In particular, many efforts have
been devoted to developing new methods based on the second-order perturbation
that may be the simplest correlated method beyond Hartree-Fock. We have
recently developed a self-consistent perturbation theory named one-body
M{\o}ller-Plesset second-order perturbation theory (OBMP2) and shown that it
can resolve issues caused by the non-iterative nature of standard perturbation
theory. In the present work, we extend the method by introducing the
spin-opposite scaling to the double-excitation amplitudes, resulting in the
O2BMP2 method. We assess the O2BMP2 performance on the triple-bond N2
dissociation, singlet-triplet gaps, and ionization potentials. O2BMP2 performs
much better than standard MP2 and reaches the accuracy of coupled-cluster
methods in all cases considered in this work.Comment: 22 pages, 9 figures, 2 table
Allelic polymorphism of crtRB1 and LcyE genes related to the β-carotene content in Vietnamese traditional maize accessions,
Maize is the third most important food crop after wheat and rice. Maize is used as food for more than a billion people around the world and is used as animal feed, especially, poultry. The concentration of carotenoids, especially, β-carotene in maize grains, is very low. Therefore, the study of increasing the amount of provitamin A carotenoids including β-carotene is important. In maize, different alleles of crtRB1 and LcyE genes have a significant effect on β-carotene content. In this paper, we present the results of the study of allele polymorphism of these two genes related to the provitamin A carotenoid content in some traditional maize accessions collected from several regions in North and Central Highlands of Vietnam. The results showed that there were polymorphisms at the 3’ and 5’ ends of the crtRB1 and LcyE genes. Among 22 maize accessions, the proportion of favorable alleles at the 3’ end of crtRB1 gene was relatively high (5/22 = 22.73%). Similar results were obtained for alleles at 3’ end of the LcyE gene. Especially, there is an accession (Northern white gold maize) that carries favorable alleles at the 3’ ends of both crtRB1 and LcyE genes. While all investigated maize accessions did not carry favorable alleles at the 5’ end of both crtRB1 and LcyE genes. The identification of traditional maize accessions that carry favorable alleles for increasing b-carotene content opens up potential to exploit indigenous genetic resources for genetic research as well as to develop maize varieties with high β- carotene content.
Synthesis, structural characterization, and application of N-doped TiO2 photocatalyst under visible-light irradiation
N-doped TiO2 nanomaterials were prepared with the sol-gel method. The structure and properties of the materials were characterized by using XRD, UV-Vis, SEM, EDX, and IR techniques. The optimal dose of ammonium chloride for doping is 600 mg. The optical absorption edge of N-TiO2 displays a redshift, and a long tail occurs in the presence of nitrogen in the material. Thereby, N-TiO2 may exhibit improved absorption properties under visible light and the solar irradiation. The photocatalytic activity was investigated on the degradation of rhodamine B. The optimal amount of the photocatalyst is 1.8 g/L under visible light
ATMOSPHERIC PARTICLES IN HOCHIMINH SIZE DISTRIBUTION OF WATER-SOLUBLE INORGANIC IONS
Joint Research on Environmental Science and Technology for the Eart
Website Quality and Intention to Use Real Estate Website in Housing Market
The purpose of this study is to operationalize the impact of some factors of real estate website quality on behavioral intention to use in searching information about housing market. Research model is the integration of extended Technology Acceptance Model (TAM) of Davis and Information Success System of DeLone and McLean. The data of 847 real estate website users from Hanoi and Ho Chi Minh City was analyzed by Structural Equation Model (SEM) and multiple group analysis. The findings indicate that most of all hypotheses received support from data, specifically, Perceived Enjoyment has the most positive impact on Attitude and Behavioral Intention of real estate website users. Moreover, there is difference in the degree of impact of website quality between the perception of users in Hanoi and Ho Chi Minh City. Keywords: real estate website, website quality, housing market, searching information DOI: 10.7176/EJBM/13-11-09 Publication date:June 30th 202
AIR POLLUTION REDUCE PRODUCTION AND LEAVE AREA OF RED RADISH (Rapahanus sativus cv. Red Chime) AND CHINESE VEGETABLE (Brassica campestris var. rosularis cv. ATU171)
Joint Research on Environmental Science and Technology for the Eart
A propensity score matching analysis of the relationship between forest resources and household welfare in Vietnam
Using secondary data from a socio-economic quantitative household survey in of the North Central region of Vietnam, the main aim of our study is to analyze the causal effect of forest resources on household income and poverty. Based on the observed characteristics of a forest-based livelihood and forest-related activities, we use a propensity score matching (PSM) method to control for potential bias arising from self-selection. The PSM results indicate that households with a forest livelihood had a higher level of income and lower level of poverty than did those without. Interestingly, our findings confirm that a forest-based livelihood offers much higher income than any other type of livelihood adopted by local households. Also, the poverty rate among households with a forest livelihood is lower than those earning non-labor income or engaged in wage/crop and crop livelihoods. Moreover, households whose livelihoods depend on timber forest products (TFPs) and animals (non-TFPs) also had higher income and lower levels of poverty than did those lacking these resources. Among households and provinces, we find differing opportunities deriving from forest resources, suggesting that there are potential barriers hindering local households from pursuing a forest livelihood or participating in some forest activities. Therefore, government policy and regulations on forest management should focus on improving the access of households to forest resources, at the same time enhancing the sustainability of these resources
Ampliación del concepto “Producción más limpia”
“Cleaner production “ (CP) emerged in the aftermath of the 1987 Brundtland Commission (WCED, 1987) call for less and more efficient energy and materials use efficiency and the suggestion to substitute more harmful products (for the environment and health) by less dangerous ones. Cleaner production was the reply of industry to the inter-sectorial and socio-economic call for sustainable development. The technical aims widened. Originally they were targeted to improve en-vironmentally inferior products to less inferior ones. Today the goal is producing is quality products us-ing renewable energy efficiently and producing zero waste, while emitting no pollution.The perspective of the scope also changed from en-vironmental sustainability to the wider “Corporate Social Responsibility” (CSR). This includes that post-modern companies have not only responsibili-ties on their economic performance and the environ-ment, but should also act on issues including human rights and resources, business ethics, and community involvement. This widening of contents necessitates more and better adapted methods. During the past 45 years the number of assessment methods (preventing pollution and its effects) increased significantly from environmental aspects (EIA), over health (HIA) and policy aspects (SEA), to sustainability assessment, addressing not only environmental, but in an inte-grated way also social, economic, and ethical issues of the evaluation.This paper reviews this evolution of ideas. It provides not only the concepts, but is equally based on case studies and examples illustrating different aspects of this evolution. It acts as a guide towards contempo-rary CSR and advocates its support towards educa-tion and research.“Producción más limpia” (CP) surgió a raíz de la Comi-sión Brundtland de 1987 con el objetivo de requerir me-nos energía y de manera más eficiente con respecto a su uso, sugiriendo sustituir los productos más nocivos (por el medio ambiente y la salud) por menos peligroso; la pro-ducción más limpia, fue la respuesta de la industria a la llamada inter-sectorial y socioeconómica para el desarro-llo sostenible. Los objetivos técnicos se abrieron ya que originalmente estaban dirigidos a mejorar los productos de calidad medioambiental inferior a los menos inferio-res. Hoy en día el objetivo es producir productos de calidad utilizando energía renovable eficiente y productoras de re-siduos cero, mientras que emite ninguna contaminación.Desde la perspectiva del ámbito de aplicación se incorpora la sostenibilidad ambiental a la “Responsabilidad Social Empresarial” más ancha (RSE). Esto incluye que las em-presas de post-modernos no sólo tienen responsabilidades sobre su desempeño económico y el medio ambiente, sino que también deben actuar en temas como los derechos hu-manos y los recursos, la ética empresarial, y participación de la comunidad. Esta ampliación de contenidos requie-re más y mejor adaptados métodos. Durante los últimos 45 años el número de métodos de evaluación (prevención de la contaminación y sus efectos) aumentó significativa-mente de los aspectos ambientales (EIA), más de la salud (EIS) y los aspectos de política (SEA), con la evaluación de la sostenibilidad, abordar no sólo el medio ambiente, pero en una también forma integrada social, económica, y las cuestiones éticas de la evaluación.Este documento analiza esta evolución de las ideas. Ofre-ciendo no sólo los conceptos, sino que se basa igualmente en estudios de casos y ejemplos que ilustran diferentes aspectos de esta evolución. Actúa como una guía hacia la RSE contemporánea y aboga por su apoyo hacia la educa-ción y la investigació
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