899 research outputs found

    Structure and Magnetism of Mn5Ge3 Nanoparticles

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    In this work, we investigated the magnetic and structural properties of isolated Mn5Ge3 nanoparticles prepared by the cluster-beam deposition technique. Particles with sizes between 7.2 and 12.6 nm were produced by varying the argon pressure and power in the cluster gun. X-ray diffraction (XRD)and selected area diffraction (SAD) measurements show that the nanoparticles crystallize in the hexagonal Mn5Si3-type crystal structure, which is also the structure of bulk Mn5Ge3. The temperature dependence of the magnetization shows that the as-made particles are ferromagnetic at room temperature and have slightly different Curie temperatures. Hysteresis-loop measurements show that the saturation magnetization of the nanoparticles increases significantly with particle size, varying from 31 kA/m to 172 kA/m when the particle size increases from 7.2 to 12.6 nm. The magnetocrystalline anisotropy constant K at 50 K, determined by fitting the high-field magnetization data to the law of approach to saturation, also increases with particle size, from 0.4 Ă— 105 J/m3 to 2.9 Ă— 105 J/m3 for the respective sizes. This trend is mirrored by the coercivity at 50 K, which increases from 0.04 T to 0.13 T. A possible explanation for the magnetization trend is a radial Ge concentration gradient

    Family, society and the individual: determinants of entrepreneurial attitudes among youth in Chennai, South India

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    High rates of youth unemployment across the world have captured the attention of many world organizations and other policy makers. One policy solution that has been proposed to curb these high rates is encouraging youth entrepreneurship. In this paper, we examine the formation of attitudes that are favorable to entrepreneurship using data from 185 business students in South India. We adopt an approach that tests the relative efficacy of two principal factors in the formation of entrepreneurial attitude, i.e., stocks of youth human/social capital and a series of personality traits. Results from a probit model suggest that the youth’s prior labor market experience, the social capital that youth have accumulated through volunteering, and the social connections that parents have made are all highly predictive of pro-entrepreneurial attitudes; personality traits exert less importance. Implications for these findings are discussed for the creation of strategies that can stimulate entrepreneurship among youth as one way to combat high rates of youth unemployment

    Structure and Magnetism of Co2Ge Nanoparticles

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    The structural and magnetic properties of Co2Ge nanoparticles (NPs) prepared by the cluster-beam deposition (CBD) technique have been investigated. As-made particles with an average size of 5.5 nm exhibit a mixture of hexagonal and orthorhombic crystal structures. Thermomagnetic measurements showed that the as-made particles are superparamagnetic at room temperature with a blocking temperature (TB) of 20 K. When the particles are annealed at 823 K for 12 h, their size is increased to 13 nm and they develop a new orthorhombic crystal structure, with a Curie temperature (TC) of 815 K. This is drastically different from bulk, which are ferromagnetic at cryogenic temperatures only. X-ray diffraction (XRD) measurements suggest the formation of a new Co-rich orthorhombic phase (OP) with slightly increased c/a ratio in the annealed particles and this is believed to be the reason for the drastic change in their magnetic properties

    Structure and Magnetism of Mn5Ge3 Nanoparticles

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    In this work, we investigated the magnetic and structural properties of isolated Mn5Ge3 nanoparticles prepared by the cluster-beam deposition technique. Particles with sizes between 7.2 and 12.6 nm were produced by varying the argon pressure and power in the cluster gun. X-ray diffraction (XRD)and selected area diffraction (SAD) measurements show that the nanoparticles crystallize in the hexagonal Mn5Si3-type crystal structure, which is also the structure of bulk Mn5Ge3. The temperature dependence of the magnetization shows that the as-made particles are ferromagnetic at room temperature and have slightly different Curie temperatures. Hysteresis-loop measurements show that the saturation magnetization of the nanoparticles increases significantly with particle size, varying from 31 kA/m to 172 kA/m when the particle size increases from 7.2 to 12.6 nm. The magnetocrystalline anisotropy constant K at 50 K, determined by fitting the high-field magnetization data to the law of approach to saturation, also increases with particle size, from 0.4 x 105 J/m3 to 2.9 x 105 J/m3 for the respective sizes. This trend is mirrored by the coercivity at 50 K, which increases from 0.04 T to 0.13 T. A possible explanation for the magnetization trend is a radial Ge concentration gradient

    Structure and Magnetism of Mn5Ge3 Nanoparticles

    Get PDF
    In this work, we investigated the magnetic and structural properties of isolated Mn5Ge3 nanoparticles prepared by the cluster-beam deposition technique. Particles with sizes between 7.2 and 12.6 nm were produced by varying the argon pressure and power in the cluster gun. X-ray diffraction (XRD)and selected area diffraction (SAD) measurements show that the nanoparticles crystallize in the hexagonal Mn5Si3-type crystal structure, which is also the structure of bulk Mn5Ge3. The temperature dependence of the magnetization shows that the as-made particles are ferromagnetic at room temperature and have slightly different Curie temperatures. Hysteresis-loop measurements show that the saturation magnetization of the nanoparticles increases significantly with particle size, varying from 31 kA/m to 172 kA/m when the particle size increases from 7.2 to 12.6 nm. The magnetocrystalline anisotropy constant K at 50 K, determined by fitting the high-field magnetization data to the law of approach to saturation, also increases with particle size, from 0.4 Ă— 105 J/m3 to 2.9 Ă— 105 J/m3 for the respective sizes. This trend is mirrored by the coercivity at 50 K, which increases from 0.04 T to 0.13 T. A possible explanation for the magnetization trend is a radial Ge concentration gradient

    High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Variable Codes)

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    The attachment includes the operational definitions of the variable codes for the following article: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)

    High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Search Terms)

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    Search Terms used in this manuscriptSearch Terms attached for the following paper: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)
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