1,656 research outputs found

    Online collaboration platforms: Communication implications for workplace virtual teams

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    As more organizations face the growing need to accommodate employees who are unable to work in a traditional face-to-face office environment, many turn to new computer programs that can connect all employees. These programs, generally referred to as online collaboration platforms, help to connect members of an organization while enhancing productivity and allowing work to be completed from around the world. While there is extensive research on the structure and nature of communication within virtual teams, there has been little research on the implications of online collaboration platforms on virtual teams. This study demonstrates how employees work with one another and communicate while using online collaboration platforms. This study featured interviews conducted at multiple businesses for data collection with the intent of exploring different uses of online collaboration platforms, finding that online collaboration platforms are making virtual work more convenient, particularly when used by virtual teams. By studying the differentiating perspectives of multiple organizations, this study contrasts the differences in usage of the software and the perceived impact that using the software has on the workplace communication of its users

    High thermoelectric performance of bornite through control of the Cu(II) content and vacancy concentration

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    The thermoelectric performance of the p-type semiconductor bornite, Cu5FeS4, is greatly enhanced through chemical substitution. Non-stoichiometric materials in which the Cu:Fe ratio and overall cation-vacancy con-tent were adjusted are reported and a figure of merit, ZT = 0.79, is achieved at temperatures as low as 550 K in Cu4.972Fe0.968S4. All materials were synthesised mechanochemically and characterised by powder X-ray diffrac-tion, DSC and thermal and electrical transport property measurements. Single-phase behaviour is retained in copper deficient phases, Cu5-xFeS4, for vacancy levels up to x = 0.1, while in materials Cu5+yFe1-yS4, in which the Cu:Fe ratio is varied whilst maintaining full occupancy of cation sites, single-phase behaviour persists for y≤0.08. Adjusting the Cu:Fe ratio at a constant cation-vacancy level of 0.06 in Cu4.94+zFe1-zS4, leads to single-phases for z ≤0.04. DSC measurements indicate the temperature of the intermediate- (2a) to high-temperature (a) phase transition shows a more marked dependence on the Cu:Fe ratio than the lower temperature 4a to 2a transition. The thermoelectric power factor increases almost linearly with increasing Cu(II) content. The maximum figures of merit are obtained for materials with Cu(II) contents in the range 0.10 to 0.15 (corresponding to 2.0 – 2.8 % Cu(II)) which simultaneously contain ca .1 % of cation vacancies

    The impact of charge transfer and structural disorder on the thermoelectric properties of cobalt intercalated TiS2

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    A family of phases, CoxTiS2 (0 ≤ x ≤ 0.75) has been prepared and characterised by powder X-ray and neutron diffraction, electrical and thermal transport property measurements, thermal analysis and SQUID magnetometry. With increasing cobalt content, the structure evolves from a disordered arrangement of cobalt ions in octahedral sites located in the van der Waals’ gap (x ≤ 0.2), through three different ordered vacancy phases, to a second disordered phase at x ≥ 0.67. Powder neutron diffraction reveals that both octahedral and tetrahedral inter-layer sites are occupied in Co0.67TiS2. Charge transfer from the cobalt guest to the TiS2 host affords a systematic tuning of the electrical and thermal transport properties. At low levels of cobalt intercalation (x < 0.1), the charge transfer increases the electrical conductivity sufficiently to offset the concomitant reduction in |S|. This, together with a reduction in the overall thermal conductivity leads to thermoelectric figures of merit that are 25 % higher than that of TiS2, ZT reaching 0.30 at 573 K for CoxTiS2 with 0.04 ≤ x ≤ 0.08. Whilst the electrical conductivity is further increased at higher cobalt contents, the reduction in |S| is more marked due to the higher charge carrier concentration. Furthermore both the charge carrier and lattice contributions to the thermal conductivity are increased in the electrically conductive ordered-vacancy phases, with the result that the thermoelectric performance is significantly degraded. These results illustrate the competition between the effects of charge transfer from guest to host and the disorder generated when cobalt cations are incorporated in the inter-layer space

    Volatiles Loss from Water Bearing Regolith Simulant at Lunar Environments

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    Permanently shadowed craters at the lunar poles contain water, ~5 wt% according to LCROSS. Interest in water for ISRU applications. Desire to 'ground truth' water using surface prospecting; e.g. Resource Prospector (RP) & RESOLVE. How to access subsurface water resources and accurately measure quantity; Excavation operations and exposure to lunar environment may affect the results A series a ground based dirty thermal vacuum tests are being conducted to better understand the subsurface sampling operations: Sample removal and transfer, Volatiles loss during sampling operations, Concept of operations, Instrumentation. This presentation covers: The capabilities of the VF-13 Thermal Vacuum Chamber (Tvac). The Resource Prospector TVAC hardware. The summary and results of 5 years of RP volatiles tests; 43 viable sample

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    LGR5 receptor promotes cell-cell adhesion in stem cells and colon cancer cells via the IQGAP1 -Rac1 pathway

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    Leucine-rich repeat-containing G protein–coupled receptor 5 (LGR5) is a bona fide marker of adult stem cells in several epithelial tissues, most notably in the intestinal crypts, and is highly up-regulated in many colorectal, hepatocellular, and ovarian cancers. LGR5 activation by R-spondin (RSPO) ligands potentiates Wnt/β-catenin signaling in vitro; however, deletion of LGR5 in stem cells has little or no effect on Wnt/β-catenin signaling or cell proliferation in vivo. Remarkably, modulation of LGR5 expression has a major impact on the actin cytoskeletal structure and cell adhesion in the absence of RSPO stimulation, but the molecular mechanism is unclear. Here, we show that LGR5 interacts with IQ motif-containing GTPase-activating protein 1 (IQGAP1), an effector of Rac1/CDC42 GTPases, in the regulation of actin cytoskeleton dynamics and cell–cell adhesion. Specifically, LGR5 decreased levels of IQGAP1 phosphorylation at Ser-1441/1443, leading to increased binding of Rac1 to IQGAP1 and thus higher levels of cortical F-actin and enhanced cell–cell adhesion. LGR5 ablation in colon cancer cells and crypt stem cells resulted in loss of cortical F-actin, reduced cell–cell adhesion, and disrupted localization of adhesion-associated proteins. No evidence of LGR5 coupling to any of the four major subtypes of heterotrimeric G proteins was found. These findings suggest that LGR5 primarily functions via the IQGAP1–Rac1 pathway to strengthen cell–cell adhesion in normal adult crypt stem cells and colon cancer cells
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