614 research outputs found

    Electrical Properties of (1–x)La2Mo2O9-xLa2Mo3O12 (x = 0.15) Composite System

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    Electrical properties of (1–x)La2Mo2O9 –xLa2Mo3O12 (x = 0.15) composite system areinvestigated. Introduction of an inert additional phase La2Mo3O12 (adjacent phase to La2Mo2O9 in the phase diagram) results in an increase in conductivity of composite by approximately one order of magnitude. This increase is associated with the appearance of a composite effect. The dominant ionic conductivity is maintained in the wide range of oxygen partial pressures. The calculated ion transport numbers are close to 1. Keywords: lanthanum molybdate, LAMOX, heterogeneous doping, composites, oxide–ion conductivit

    Zee electrical interconnect

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    An interconnect, having some length, that reliably connects two conductors separated by the length of the interconnect when the connection is made but in which one length if unstressed would change relative to the other in operation. The interconnect comprises a base element an intermediate element and a top element. Each element is rectangular and formed of a conducting material and has opposed ends. The elements are arranged in a generally Z-shape with the base element having one end adapted to be connected to one conductor. The top element has one end adapted to be connected to another conductor and the intermediate element has its ends disposed against the other end of the base and the top element. Brazes mechanically and electrically interconnect the intermediate element to the base and the top elements proximate the corresponding ends of the elements. When the respective ends of the base and the top elements are connected to the conductors, an electrical connection is formed therebetween, and when the conductors are relatively moved or the interconnect elements change length the elements accommodate the changes and the associated compression and tension forces in such a way that the interconnect does not mechanically fatigue

    The effect of heterogeneous doping on transport properties of lanthanum dimolybdate

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    A heterogeneous doping method was used for the first time to modify the transport properties of the oxygen-ion conductor La(2)Mo(2)O(9). The effect of temperature and oxygen partial pressure in the gas phase on conductivity of the obtained composite {0.85La2Mo2O9–0.15La2Mo3O12} was studied. Introduction of 15 mol. % an inert low-conductive additional phase La(2)Mo(3)O(12) results in an increase in conductivity of the matrix phase by nearly 1 orders of magnitude. It is associated with appearance of a composite effect. However, there is no suppression of the α-La(2)Mo(2)O(9)↔β-La(2) Mo(2)O(9) phase transition. It is shown that the conductivity type of both lanthanum dimolybdate and composite based on it is predominantly ionic in the wide range of oxygen partial pressures. © Siberian Federal University. All rights reserve

    Tight-binding study of interface states in semiconductor heterojunctions

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    Localized interface states in abrupt semiconductor heterojunctions are studied within a tight-binding model. The intention is to provide a microscopic foundation for the results of similar studies which were based upon the two-band model within the envelope function approximation. In a two-dimensional description, the tight-binding Hamiltonian is constructed such that the Dirac-like bulk spectrum of the two-band model is recovered in the continuum limit. Localized states in heterojunctions are shown to occur under conditions equivalent to those of the two-band model. In particular, shallow interface states are identified in non-inverted junctions with intersecting bulk dispersion curves. As a specific example, the GaSb-AlSb heterojunction is considered. The matching conditions of the envelope function approximation are analyzed within the tight-binding description.Comment: RevTeX, 11 pages, 3 figures, to appear in Phys. Rev.

    PHYSICO-CHEMICAL ATTESTATION OF COMPOSITE SYSTEMS BASED ON ACCEPTOR-DOPED La2Mo2O9 (LAMOX)

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    The aim of work is to enhance ionic conductivity of the La2Mo2O9 by heterogeneous and homogeneous doping. The phases La2Mo2O9 (LM), La2Mo1,5W0,5O9 (LMW), La1,9Ba0,1Mo1,5W0,5O9 (LBMW) and La2Mo1,4Nb0,1W0,5O9 (LMNW) as well ascomposites {(100-y)La2Mo2-xTixO9-δ-yTiO2} (LM-yTi) and {(100-y)La2Mo1,5-xTixW0,5O9-δ-yTiO2} (LMW-yTi)were obtained by solid phase synthesis.Phase composition was checked by Xray diffraction analysis. Electrical properties were examined by impedance spectroscopy.Работа выполнена в рамках государственного задания Минобрнауки РФ

    Interface states in junctions of two semiconductors with intersecting dispersion curves

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    A novel type of shallow interface state in junctions of two semiconductors without band inversion is identified within the envelope function approximation, using the two-band model. It occurs in abrupt junctions when the interband velocity matrix elements of the two semiconductors differ and the bulk dispersion curves intersect. The in-plane dispersion of the interface state is found to be confined to a finite range of momenta centered around the point of intersection. These states turn out to exist also in graded junctions, with essentially the same properties as in the abrupt case.Comment: 1 figur

    Contribution of patient, physician, and environmental factors to demographic and health variation in colonoscopy follow-up for abnormal colorectal cancer screening test results

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    BACKGROUND: Patient, physician, and environmental factors were identified, and the authors examined the contribution of these factors to demographic and health variation in colonoscopy follow-up after a positive fecal occult blood test/fecal immunochemical test (FOBT/FIT) screening. METHODS: In total, 76,243 FOBT/FIT-positive patients were identified from 120 Veterans Health Administration (VHA) facilities between August 16, 2009 and March 20, 2011 and were followed for 6 months. Patient demographic (race/ethnicity, sex, age, marital status) and health characteristics (comorbidities), physician characteristics (training level, whether primary care provider) and behaviors (inappropriate FOBT/FIT screening), and environmental factors (geographic access, facility type) were identified from VHA administrative records. Patient behaviors (refusal, private sector colonoscopy use) were estimated with statistical text mining conducted on clinic notes, and follow-up predictors and adjusted rates were estimated using hierarchical logistic regression. RESULTS: Roughly 50% of individuals completed a colonoscopy at a VHA facility within 6 months. Age and comorbidity score were negatively associated with follow-up. Blacks were more likely to receive follow-up than whites. Environmental factors attenuated but did not fully account for these differences. Patient behaviors (refusal, private sector colonoscopy use) and physician behaviors (inappropriate screening) fully accounted for the small reverse race disparity and attenuated variation by age and comorbidity score. Patient behaviors (refusal and private sector colonoscopy use) contributed more to variation in follow-up rates than physician behaviors (inappropriate screening). CONCLUSIONS: In the VHA, blacks are more likely to receive colonoscopy follow-up for positive FOBT/FIT results than whites, and follow-up rates markedly decline with advancing age and comorbidity burden. Patient and physician behaviors explain race variation in follow-up rates and contribute to variation by age and comorbidity burden. Cancer 2017;123:3502-12. Published 2017. This article is a US Government work and is in the public domain in the USA

    Communicating with providers about racial healthcare disparities: The role of providers’ prior beliefs on their receptivity to different narrative frames

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    Objective Evaluate narratives aimed at motivating providers with different pre-existing beliefs to address racial healthcare disparities. Methods Survey experiment with 280 providers. Providers were classified as high or low in attributing disparities to providers (HPA versus LPA) and were randomly assigned to a non-narrative control or 1 of 2 narratives: “Provider Success” (provider successfully resolved problem involving Black patient) and “Provider Bias” (Black patient experienced racial bias, which remained unresolved). Participants' reactions to narratives (including identification with narrative) and likelihood of participating in disparities-reduction activities were immediately assessed. Four weeks later, participation in those activities was assessed, including self-reported participation in a disparities-reduction training course (primary outcome). Results Participation in training was higher among providers randomized to the Provider Success narrative compared to Provider Bias or Control. LPA participants had higher identification with Provider Success than Provider Bias narratives, whereas among HPA participants, differences in identification between the narratives were not significant. Conclusions Provider Success narratives led to greater participation in training than Provider Bias narratives, although providers’ pre-existing beliefs influenced the narrative they identified with. Practice implications Provider Success narratives may be more effective at motivating providers to address disparities than Provider Bias narratives, though more research is needed
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