39 research outputs found

    Shape grammar based adaptive building envelopes: Towards a novel climate responsive facade systems for sustainable architectural design in Vietnam.

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    The concept of a dynamic building enclosure is a relatively novel and unexplored area in sustainable architectural design and engineering and as such, could be considered a new paradigm. These façade systems, kinetic and adaptive in their nature, can provide opportunities for significant reductions in building energy use and CO2 emissions, whilst at the same time having a positive impact on the quality of the indoor environment. Current research in this area reports on a growing increase in the application of new generative design approaches and computational techniques to assist the design of adaptable kinetic systems and to help quantify their relationships between the building envelope and the environment. In this research, a novel application of shape grammar for the design of kinetic façade shading systems has been developed, based upon a generative design approach that controls the creation of complex shape composites, starting from a set of initial shapes and pre-defined rules of their composition. Shape grammars provide an interesting generative design archetype in which a set of shape rules can be recursively applied to create a language of designs, with the rules themselves becoming descriptors of such generated designs. The research is inspired by traditional patterns and ornaments in Vietnam, seen as an important symbol of its cultural heritage, especially in the era of globalisation where many developing countries, including Vietnam, are experiencing substantial modernist transformations in their cities. Those are often perceived as a cause of the loss of both visual and historical connections with indigenous architectural origins and traditions. This research hence investigates how these aspects of spatial culture could be interpreted and used in designing of novel façade shading systems that draw their inspiration from Vietnamese vernacular styles and cultural identity. At the same time, they also have to satisfy modern building performance demands, such as a reduction in energy consumption and enhanced indoor comfort. This led to the exploration of a creative form-finding for different building façade shading configurations, the performance of which was tested via simulation and evaluation of indoor daylight levels and corresponding heating and cooling loads. The developed façade structures are intended to adapt real-time, via responding to both results of an undertaken simulation and data-regulation protocols responsible for sensing and processing building performance data. To this extent, a strategy for BIM integrated sustainable design analysis (SDA) has also been deliberated, as a framework for exploring the integration of building management systems (BMS) into smart building environments (SBEs). Finally, the research reports on the findings of a prototype system development and its testing, allowing continuous evaluation of multiple solutions and presenting an opportunity for further improvement via multi-objective optimisation, which would be very difficult to do, if not impossible, with conventional design methods.N/

    The relation between university GPA and family background: Evidence from a university in Vietnam

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    Based on three data sets of information on students of a university in Vietnam, we estimate the factors affecting GPA by using the two-stage least squares (2SLS) method. The results of estimation highlight that parents’ occupation as farmers and living location in rural areas have an adverse impact on the GPA of students at university (University GPA). Causally, the government does not control or monitor the hours of part-time work of students earning a living cost and tuition fee, which rise dynamically in city located the university. Furthermore, we also find a positive relation between national university entrance point and the university GPA

    Embedding Sustainable Consumption into Higher Education in Vietnam

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    Changing in the way that human produces and consumes are indispensable to achieve sustainable consumption. All of the countries in developed economies, economies in transition and developing economies should promote sustainable consumption. This will require larger changes in society. Higher education plays a vital role in promoting understanding, awareness of professors, staff members and students of sustainable consumption. Through higher education, these people would be positively change their mind about this issue. National Economics University (NEU) is one of the leading university in economics in Vietnam as a case study. Students graduated from the university will be future experts, leaders and businessmen. After graduation, as academic citizens with acquainted knowledge and skills, they will influence the economic and social changes though their business and private purchasing habits and decisions. Using data from the University, this paper will reveal the current landscape of sustainable consumption at National Economics University through the years. In order to embed this issues into education, the university should incorporate sustainable consumption into the curriculum, create and implement a sustainability plan and adjust teaching method to encourage students asking questions, analyzing, thinking critically and making decisions toward sustainable consumption. Keywords: Embedding sustainable consumption, higher education DOI: 10.7176/EJBM/11-18-12 Publication date:June 30th 201

    All-dielectric Metamaterial for Electromagnetically-induced Transparency in Optical Region

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    Metamaterial (MM) is emerging as a promising approach to manipulate electromagnetic waves, spanning from radio frequency to the optical region. In this paper, we employ an effect called electromagnetically-induced transparency (EIT) in all-dielectric MM structures to create a narrow transparent window in opaque broadband of the optical region (580-670 nm). Using dielectric materials instead of metals can mitigate the large non-radiative ohmic loss on the metal surface. The unit-cell of MM consists of Silicon (Si) bars on Silicon dioxide (SiO2_{2}) substrate, in which two bars are directed horizontally and one bar is directed vertically. By changing the relative position and dimension of the Si bars, the EIT effect could be achieved. The optical properties of the proposed MM are investigated numerically using the finite difference method with commercial software Computer Simulation Technology (CST). Then, characteristic parameters of MM exhibiting EIT effect (EIT-MM), including Q-factor, group delay, are calculated to evaluate the applicability of EIT-MM to sensing and light confinement

    Short Tandem Repeats Used in Preimplantation Genetic Testing of Î’-Thalassemia: Genetic Polymorphisms For 15 Linked Loci in the Vietnamese Population

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    BACKGROUND: β-thalassemia is one of the most common monogenic diseases worldwide. Preimplantation genetic testing (PGT) of β-thalassemia is performed to avoid affected pregnancies has become increasingly popular worldwide. In which, the indirect analysis using short tandem repeat (STRs) linking with HBB gene to detect different β-globin (HBB) gene mutation is a simple, accurate, economical and also provides additional control of contamination and allele-drop-out ADO. AIM: This study established microsatellite markers for PGT of Vietnamese β-thalassemia patient. METHODS: Fifteen (15) STRs gathered from 5 populations were identified by in silico tools within 1 Mb flanking the HBB gene. The multiplex PCR reaction was optimized and performed on 106 DNA samples from at-risk families. RESULTS: After estimating, PIC values were ≥ 0.7 for all markers, with expected heterozygosity and observed heterozygosity values ranged from 0.81 to 0.92 and 0.53 to 0.86, respectively. One hundred percent of individuals had at least seven heterozygous markers and were found to be heterozygous for at least two markers on either side of the HBB gene. The STRs panel was successfully performed on one at-risk family. CONCLUSION: In general, a pentadecaplex marker (all < 1 Mb from the HBB gene) assay was constituted for β-thalassemia PGT on Vietnamese population

    Low birth weight of Vietnamese infants is related to their mother’s dioxin and glucocorticoid levels

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    We aimed to determine the relationship between dioxin congeners in maternal breast milk and maternal glucocorticoid levels with newborn birth weight after nearly 45 years of use of herbicides in the Vietnam War. The study subjects comprised 58 mother–infant pairs in a region with high dioxin levels in the soil (hotspot) and 62 pairs from a control region. Dioxin levels in maternal breast milk were measured by HRGC-HRMS. Salivary glucocorticoid levels were determined by LC-MS/MS. Dioxin congener levels in mothers from the hotspot were found to be two to fivefold higher than those in mothers from the control region. Birth weight was inversely correlated with 2,3,7,8-TeCDD and 2,3,4,7,8-PeCDF congener levels. The rate of newborns whose birth weight was less than 2500 g was threefold higher in the hotspot (12 %) than in the control region (4 %). Salivary glucocorticoid levels in mothers with low birth weight infants were significantly higher than those in the normal birth weight group. Low birth weight of Vietnamese newborns in a hotspot for dioxin levels is related to some dioxin congener levels and high glucocorticoid levels in mothers. This finding in mother–infant pairs suggests that excess maternal glucocorticoid levels are related to dioxin burden and they result in low birth weight. © 2016 Springer-Verlag Berlin HeidelbergEmbargo Period 12 month

    High cortisol and cortisone levels are associated with breast milk dioxin concentrations in Vietnamese women

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    Objective: Dioxin (polychlorinated dibenzodioxins Cpolychlorinated dibenzofurans) is one of the most toxic chemical substances known. Although it is suspected to cause endocrine disruption, very few epidemiological studies have been carried out on its effects on human steroid hormones. The aim of this study was to elucidate the association of dioxin exposure with steroid hormone levels in the saliva and serum of Vietnamese women. Study design : Two areas, namely Phu Cat (hot spot) and Kim Bang (nonexposed area), were selected for the study. The study subjects consisted of 51 and 58 women respectively. Saliva, blood, and breast milk samples were collected from the subjects in both the areas. Methods: Cortisol, cortisone, DHEA, androstenedione, estrone, and estradiol levels in serum and saliva were determined by liquid chromatography-tandem mass spectrometry; dioxin concentrations in breast milk were measured by gas chromatography-mass spectrometry. Results: Dioxin concentrations in the breast milk of women from the dioxin hot spot were three to four times higher than those in the breast milk of women from the nonexposed area. Good correlations were found between the levels of six steroid hormones in saliva and those in serum respectively. Salivary and serum cortisol and cortisone levels in women from the dioxin hot spot were significantly higher than those in women from the nonexposed area (P<0.001) and those in all the subjects were positively associated with dioxin concentrations in Vietnamese women (P<0.01). Conclusion: These results suggest that dioxin influences steroidogenesis in humans. Saliva samples can be used for hormone analysis and are therefore excellent specimens in epidemiological studies. © 2014 European Society of Endocrinology

    Levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans in breast milk samples from three dioxin-contaminated hotspots of Vietnam

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    We determined polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels in breast milk of 143 primiparae living around the three most dioxin-contaminated areas of Vietnam. The women sampled lived in the vicinity of former U.S. air bases at Bien Hoa (n. =. 51), Phu Cat (n. =. 23), and Da Nang (n. =. 69), which are known as dioxin hotspots. Breast milk samples from Bien Hoa City, where residents live very close to the air base, showed high levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with 18% of the samples containing >. 5. pg. TCDD/g lipid. However, Phu Cat residents lived far from the air base and their samples showed lower TCDD levels, with none containing >. 5. pg. TCDD/g lipid. In Da Nang, TCDD levels in mothers from Thanh Khe (close to the air base, n. =. 43) were significantly higher than those in mothers from Son Tra (far from the air base, n. =. 26), but not other PCDD and PCDF (PCDD/F) congeners. Although TCDD levels in Bien Hoa were the highest among these hotspots, levels of other PCDD/F congeners as well as the geometric mean concentration of total PCDD/F level in Bien Hoa (9.3. pg toxic equivalents [TEQ]/g lipid) were significantly lower than the level observed in Phu Cat (14.1. pg. TEQ/g lipid), Thanh Khe (14.3. pg. TEQ/g lipid), and Son Tra (13.9. pg. TEQ/g lipid). Our findings indicated that residents living close to former U.S. air bases were exposed to elevated levels of TCDD, but not of other PCDD/F congeners

    Inverse association of highly chlorinated dioxin congeners in maternal breast milk with dehydroepiandrosterone levels in three-year-old Vietnamese children

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    This study aims to evaluate the endocrine-disrupting effect of dioxin congeners on adrenal steroid hormones in mother-child pairs. In our previous study, we found that cortisol and cortisone levels were higher in the blood and the saliva of mothers living in a dioxin hotspot area than in mothers from a non-exposed region in Vietnam. In this follow-up study, we determined the salivary steroid hormone levels in 49 and 55 three-year-old children of these mothers in the hotspot and non-exposed region, respectively. Steroid hormones were determined by liquid chromatography-tandem mass spectrometry, and dioxin in the maternal breast milk was determined by gas chromatography-mass spectrometry. Dioxin levels in the breast milk of mothers from the hotspot (median total toxic equivalents polychlorinated dibenzodioxins/polychlorinated dibenzofurans; (TEQ PCDD/Fs) of 11. pg/g lipid) were three to four times higher than those of mothers in the non-exposed region (median TEQ PCDD/Fs of 3.07. pg/g lipid). Salivary dehydroepiandrosterone (DHEA) levels in children were found to be significantly lower in the hotspot than in the non-exposed region, while cortisol and cortisone levels were not different between the two regions. Highly chlorinated dioxin congeners, such as octacholorodibenzodioxin (OCDD), 1,2,3,4,6,7,8-heptacholorodibenzodioxin (HpCDD) and 1,2,3,4 (or 6), 7,8-hexachlorodibenzodioxin Hx(CDD), showed stronger inverse associations with the children\u27s salivary DHEA than other lowly chlorinated dioxin congeners. Glucocorticoid levels in the mothers exhibited a significantly positive correlation with OCDD and HpCDD/F (polychlorinated dibenzofurans). In conclusion, highly chlorinated dioxin congeners are more strongly correlated with endocrine-disrupting effects on adrenal hormones, resulting in high cortisol levels in the mothers and low DHEA levels in their three-year-old children. © 2016 Elsevier B.V.Embargo Period 24 month
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