1,337 research outputs found

    ELECTRE I Method Using Hesitant Linguistic Term Sets: An Application to Supplier Selection

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    Decision making is a common process in human activities. Every person or organization needs to make decisions besides dealing with uncertainty and vagueness associated with human cognition. The theory of fuzzy logic provides a mathematical base to model the uncertainities. Hesitant fuzzy linguistic term set (HFLTS) creates an appropriate method to deal with uncertainty in decision making. Managerial decision making generally implies that decision making process conducts multiple and conflicting criteria. Multi criteria decision analysis (MCDA) is a widely applied decision making method. Outranking methods are one type of MCDA methods which facilitate the decision making process through comparing binary relations in order to rank the alternatives. Elimination et Choix Traduisant la Réalité (ELECTRE), means elimination and choice that translates reality, is an outranking method. In this paper, an extended version of ELECTRE I method using HFLTS is proposed. Finally, a real case problem is provided to illustrate the HFLTS-ELECTRE I method

    A geochemical equilibrium modeling approach to assessing soil acidification impacts due to depositions of industrial air emissions

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    Soil acidification impacts arising from depositions of industrial air emissions may become a serious environmental concern. Currently, in the literature quantitative mechanistic modeling and the experimental acid neutralizing capacity (ANC) approach and a qualitative evaluation approach classifying soils into various levels of sensitivity to acid additions have been reported to assess the long-term soil acidification impacts due to industrial air emissions. Another alternative quantitative approach proposed by this study is the geochemical modeling approach that can be used to similate an ANC curve based on relevant soil chemistry data by calculating the equilibrium distributions of chemical species in the soil solution according to the specified geochemical processes. The purpose of this syudy was essentially to illustrate the potential applications and practical utility of the proposed geochemical modeling approach to assessing soil acidification impacts due to industrial air emissions. The application of the geochemical modeling approach was illustrated by comparisons of the experimental and simulated ANC curves for a calcareous and a noncalcareous soil representing insensitive and sensitive soil cases, respectively. Results obtained from these comparisons reveal that, in terms of producing the ANC curve for the soil solution, the geochemical modeling approach seems to perform well and produce more reliable results for calcareous soil than for noncalcareous soil. However, the approach can also be used for noncalcareous soils when the air emission rates are low and may need further testing with additional measured data for a wide range of soils other than those presented in this study

    Numerical modeling of the multi-stage Stern\unicode{x2013}Gerlach experiment by Frisch and Segr\`e using co-quantum dynamics via the Bloch equation

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    We numerically study the spin flip in the Frisch\unicode{x2013}Segr\`e experiment, the first multi-stage Stern\unicode{x2013}Gerlach experiment, within the context of the novel co-quantum dynamics theory. We model the middle stage responsible for spin rotation by sampling the atoms with the Monte Carlo method and solving the dynamics of the electron and nuclear magnetic moments numerically according to the Bloch equation. Our results show that, without using any fitting parameters, the co-quantum dynamics closely reproduces the experimental observation reported by Frisch and Segr\`e in 1933, which has so far lacked theoretical predictions.Comment: 9 pages, 6 figure

    Numerical modeling of the multi-stage Stern\unicode{x2013}Gerlach experiment by Frisch and Segr\`e using co-quantum dynamics via the Schr\"odinger equation

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    We use a theory termed co-quantum dynamics (CQD) to numerically model spin flip in the multi-stage Stern\unicode{x2013}Gerlach (SG) experiment conducted by R. Frisch and E. Segr\`e. This experiment consists of two Stern\unicode{x2013}Gerlach apparatuses separated by an inner rotation chamber that varies the fraction of spin flip. To this day, quantum mechanical treatments inadequately predict the Frisch\unicode{x2013}Segr\`e experiment. Here, we account for electron-nuclear interactions according to CQD and solve the associated Schr\"odinger equation. Our simulation outcome agrees with the Frisch\unicode{x2013}Segr\`e experimental observation and supports CQD as a potential model for electron spin evolution and collapse.Comment: 13 pages, 3 figure

    Spectroscopic Survey of {\gamma} Doradus Stars I. Comprehensive atmospheric parameters and abundance analysis of {\gamma} Doradus stars

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    We present a spectroscopic survey of known and candidate γ\gamma\,Doradus stars. The high-resolution, high signal-to-noise spectra of 52 objects were collected by five different spectrographs. The spectral classification, atmospheric parameters (\teff, logg\log g, ξ\xi), vsiniv\sin i and chemical composition of the stars were derived. The stellar spectral and luminosity classes were found between G0-A7 and IV-V, respectively. The initial values for \teff\ and \logg\ were determined from the photometric indices and spectral energy distribution. Those parameters were improved by the analysis of hydrogen lines. The final values of \teff, \logg\ and ξ\xi were derived from the iron lines analysis. The \teff\ values were found between 6000\,K and 7900\,K, while \logg\,values range from 3.8 to 4.5\,dex. Chemical abundances and vsiniv\sin i values were derived by the spectrum synthesis method. The vsiniv\sin i values were found between 5 and 240\,km\,s1^{-1}. The chemical abundance pattern of γ\gamma\,Doradus stars were compared with the pattern of non-pulsating stars. It turned out that there is no significant difference in abundance patterns between these two groups. Additionally, the relations between the atmospheric parameters and the pulsation quantities were checked. A strong correlation between the vsiniv\sin i and the pulsation periods of γ\gamma\,Doradus variables was obtained. The accurate positions of the analysed stars in the H-R diagram have been shown. Most of our objects are located inside or close to the blue edge of the theoretical instability strip of γ\gamma\,Doradus.Comment: 18 pages, 13 figure

    Enhancement of mechanical and thermoelectric properties of Ca3Co4O9 by Ag addition

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    Ca3Co4O9 + x wt.% Ag (x = 0, 1, 3, 5, and 10) polycrystalline thermoelectric ceramics have been prepared by a sol–gel route via nitrates followed by high temperature treatment before sintering. Out-of-plane XRD data have shown that major phase is the Ca3Co4O9 one, accompanied by metallic Ag. SEM observations have agreed with the XRD data. Apparent density measurements have revealed that all samples possess densities ranging between 80% and 90% when Ag content is raised. Mechanical properties have shown a drastic increase of bending stress when Ag is added to the samples. Electrical resistivity decreases with the Ag content, compared with the pure ones, while Seebeck coefficient slightly decreases. Maximum power factor values around 0.43 mW/K2 m at 800 °C have been achieved for the 10 wt.% Ag samples which is much higher than the measured in the pure Ca3Co4O9 samples.This research has been supported by MINECO-FEDER (MAT2013-46505-C3-1-R). The authors wish to thank the Gobierno de Aragón-Fondo Social Europeo (Consolidated Research Groups T12 and T87) for financial support.Peer Reviewe

    Immunostimulatory activity of polysaccharide-poly(I:C) nanoparticles

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    Cataloged from PDF version of article.Immunostimulatory properties of mushroom derived polysaccharides (PS) as stand-alone agents were tested. Next. PS were nanocomplexed with polyI:C (pIC) to yield stable nanoparticles around 200 nm in size evidenced by atomic force microscopy and dynamic light scattering analyses. PSs were selectively engaged by cells expressing TLR2 and initiated NF kappa B dependent signaling cascade leading to a Th1-biased cytokine/chemokine secretion in addition to bactericidal nitric oxide (NO) production from macrophages. Moreover, cells treated with nanoparticles led to synergistic IL6, production and upregulation of TNF alpha, MIP3 alpha, IFN gamma and IP10 transcript expression. In mice, PS-Ovalbumin-pIC formulation surpassed anti-OVA IgG responses when compared to either PS-OVA or pIC-OVA mediated immunity. Our results revealed that signal transduction initiated both by TLR2 and TLR3 via co-delivery of pIC by PS in nanoparticle depot delivery system is an effective immunization strategy. The present work implicate that the PS and nucleic acid based nanoparticle approach along with protein antigens can be harnessed to prevent infectious diseases. (C) 2011 Elsevier Ltd. All rights reserve
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