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Auflistung nach Autor:in "Vu Van , Manh"

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  • Konferenzbeitrag
    Study on the freshwater boundary of the Pleistocene aquifer in the coastal zone of Nam Dinh province
    (EnviroInfo & ICT4S, Adjunct Proceedings, 2015) Nguyen Thu , Hang; Trinh Hoai , Thu; Dinh Duy , Chinh; Vu Van , Manh
    Saltwater intrusion has occurred in coastal aquifers in Nam Dinh province, Vietnam, which causes many negative effects on economic activities and especially residential life. Determining fresh-saltwater distribution is therefore necessary for authorities to have fundament to release policies and solutions timely to prevent this issue. Based on samples analyzing data, 3 regression equations of each couple of the conductivity, total dissolved solids (TDS) and chloride concentration were formulated and displayed on graphs, these can be applied to calculate TDS from available conductivity or chloride concentration values in any areas. Calculating all input data, a variogram was created, which indicates the spatial correlation between sampling points. Then, Kriging interpolation was applied in map-making process. Finally the spatial distribution of fresh and saltwater was delineated. Freshwater districts are located in the southern part of the Nam Dinh province and a small area in the north.
  • Konferenzbeitrag
    Using system dynamics model to assess aluminium price volatility and propose solutions to save energy
    (EnviroInfo & ICT4S, Adjunct Proceedings, 2015) Nguyen Thi Minh, Hanh; Dinh Duy, Chinh; Vu Van , Manh
    Aluminium production in Vietnam will increase several times over in the next few years if Dak Nong aluminium smelting project is realized. Indeed, aluminium smelting is a commodity industry with highly volatile prices. This research uses system dynamics to predict the industry to explain the part of volatility. Because of huge electricity requirement and potential to reduce electricity consumption through recycling, aluminium smelting is a special interest of environmental research. Besides the large price volatility will impact directly on production and consumption of aluminium and lead to waste or adversely affect to the environment and society. This research begins with initial model of aluminium industry. Concluding with a discussion of system dynamics and commodity production cycles, the focus is on assessing the impact of producers lag time and variable demand to price volatility. The longer the producers lag time is, the larger the price volatility is. Also with variable demand, the price will be larger fluctuated. At the end, by increasing the proportion of recycled aluminium from 25% to 40%, 8.44 Gwh of electricity power will be saved after 96 months and this will open a more sustainable direction for Vietnam aluminium industry.