2,109 research outputs found

    Influence of mixing the low-valent transition metal atoms (Y,Y^*=Cr,Mn,Fe) on the properties of the quaternary Co2_2[Y1x_{1-x}Yx^*_x]Z (Z=Al,Ga,Si,Ge,Sn) Heusler compounds

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    We complement our study on the doping and disorder in Co2_2MnZ compounds [I. Galanakis \textit{et al.}, Appl. Phys. Lett. \textbf{89}, 042502 (2006) and K. \"Ozdo\~gan \textit{et al.}, Phys. Rev. B \textbf{74}, (2006)] to cover also the quaterarny Co2_2[Y1x_{1-x}Yx^*_x]Z compounds with the lower-valent transition metals Y,Y^* being Cr, Mn or Fe and the sp atom Z being one of Al, Ga, Si, Ge, Sn. This study gives a global overview of the magnetic and electronic properties of these compounds since we vary both Y and Z elements. Our results suggest that for realistic applications the most appropriate compounds are the ones belonging to the families Co2_2[Mn1x_{1-x}Crx_x]Z with x>0.5x>0.5 irrespectively of the nature of the spsp atoms since they combine high values of majority DOS at the Fermi level due to the presence of Cr, and half-metallicity with large band-gaps. On the other hand the presence of Fe lowers considerably the majority density of states at the Fermi level and when combined with an element belonging to the Si-column, it even can destroy half-metallicity

    Effect of doping and disorder on the half-metallicity of full Heusler alloy

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    Heusler alloys containing Co and Mn are amongst the most heavily studied half-metallic ferromagnets for future applications in spintronics. Using state-of-the-art electronic structure calculations, we investigate the effect of doping and disorder on their electronic and magnetic properties. Small degrees of doping by substituting Fe or Cr for Mn scarcely affect the half-metallicity. A similar effect is also achieved by mixing the sublattices occupied by the Mn and sp atoms. Thus the half-metallicity is a robust property of these alloys

    Serious Games as a Validation Tool for Decision Support System in Disaster Management—Case of PREDIS

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    Validation of Decision Support System (DSS) through simulation games or serious game is one way of validating the cognitive capability models through expert opinion. Here, this technique is used to validate PREDIS as a model for DISaster response supplier selection (PREDIS), previously introduced by authors. This DSS is a combination of a PREDictive component (PRED) for predicting the disaster human impact, an estimation component to Estimate the DISaster (EDIS) needs and optimised for supplier based resource allocation. This paper aims to test the suitability of the PREDIS model further for decision-making in the disaster situation. A quasi-experiment design embedded in a participatory simulation game is conducted to compare the opinion of equal sample of 22 experts and non-experts. The following questions are put forward. First, “Does PREDIS model assists the decision makers to make the same decisions faster”. Second, “Does the PREDIS model assist the non-experts as simulated decision makers to decide like an expert”. Using AHP weights of decision makers’ preference as well as borda counts, the decisions are compared. The result shows that PREDIS helps to reduce the decision making time by experts and non-experts within 6 h after the disaster strike, instead of 72 h. It also assist 71% of the non-expert to make similar de-cision as experts. In summary, the PREDIS model has two major capabilities. It enables the experts and non-experts to predict the disaster results immediately and using the widely available data. It also enables the non-experts to decide almost the same as the experts; either in predicting the human impact of the disaster and estimating the needs or in selecting suitable suppliers
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