9,383 research outputs found

    Ethical responses to organizational crisis: lessons from three successful cases

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    Present research lacks adequate examples of successful and ethical approaches to organizational crisis management. Much of this research determines the effectiveness of organization\u27s post-crisis responses by examining obvious failures. This dissertation takes an alternative approach by examining ethical post-crisis communication through obvious successes. This study examined ethical responses by applying stakeholder concepts and ethical perspectives to the corporate discourse of Malden Mills, after a plant explosion, Schwan\u27s Sales Enterprises, after a salmonella outbreak, and General Motors, in response to accusations by Dateline NBC about the safety of GM C/K trucks. The study suggests that ethical responses to organizational crises can help organizations achieve effective responses. First, when an organization takes initial responsibility for a crisis they can meet the difficult objective of responding quickly and accurately to a crisis. Second, the organization can use established values as a repertoire of response to respond to crisis. Third, this research contends that if organizations establish strong relationships with stakeholders before a crisis they can establish strong networks of support that can help an organization recover from a crisis

    A Search for X-Ray Bright Distant Clusters of Galaxies

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    We present the results of a search for X--ray luminous distant clusters of galaxies. We found extended X--ray emission characteristic of a cluster towards two of our candidate clusters of galaxies. They both have a luminosity in the ROSAT bandpass of ≃1044 erg s−1\simeq10^{44}{\rm \,erg\,s^{-1}} and a redshift of >0.5>0.5; thus making them two of the most distant X--ray clusters ever observed. Furthermore, we show that both clusters are optically rich and have a known radio source associated with them. We compare our result with other recent searches for distant X--ray luminous clusters and present a lower limit of 1.2×10−7 Mpc−31.2\times10^{-7}\,{\rm Mpc^{-3}} for the number density of such high redshift clusters. This limit is consistent with the expected abundance of such clusters in a standard (b=2) Cold Dark Matter Universe. Finally, our clusters provide important high redshift targets for further study into the origin and evolution of massive clusters of galaxies. Accepted for publication in the 10th September 1994 issue of ApJ.Comment: 20 pages Latex file + 1 postscript figure file appende

    X-ray Observations of Distant Optically Selected Cluster

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    We have measured fluxes or flux limits for 31 of the 79 cluster candidates in the Palomar Distant Cluster Survey (PDCS) using archival ROSAT/PSPC pointed observations. Our X-ray survey reaches a flux limit of ≃3×10−14\simeq 3 \times 10^{-14} erg s−1^{-1} cm−2^{-2} (0.4 - 2.0 keV), which corresponds to luminosities of Lx≃5×1043L_x\simeq 5 \times 10^{43} erg s−1^{-1} (HoH_o = 50 km s−1^{-1} Mpc−1^{-1}, qoq_o = 1/2{1/2}), if we assume the PDCS estimated redshifts. Of the 31 cluster candidates, we detect six at a signal-to-noise greater than three. We estimate that 2.9−1.4+3.32.9^{+3.3}_{-1.4} (90% confidence limits) of these six detections are a result of X-ray emission from objects unrelated to the PDCS cluster candidates. The net surface density of X-ray emitting cluster candidates in our survey, 1.71−2.19+0.911.71^{+0.91}_{-2.19} clusters deg−2^{-2}, agrees with that of other, X-ray selected, surveys. It is possible, given the large error on our contamination rate, that we have not detected X-ray emission from any of our observed PDCS cluster candidates. We find no statistically significant difference between the X-ray luminosities of PDCS cluster candidates and those of Abell clusters of similar optical richness. This suggests that the PDCS contains objects at high redshift similar to the low redshift clusters in the Abell catalogs. We show that the PDCS cluster candidates are not bright X-ray sources, the average luminosity of the six detected candidates is only Lxˉ=0.9×1044\bar{L_x}=0.9\times10^{44} erg s−1^{-1} (0.4-2.0 keV). This finding is in agreement with previous X-ray studies of high redshift, optically selected, rich clusters of galaxies.Comment: 19 pages, LaTeX with AAS Preprint Macros (v. 4), 3 embedded postscript figures, 3 Seperate Tables using aj_pt4.sty, Accepted by the Astronomical Journal for November 199

    Market assessment of photovoltaic power systems for agricultural applications worldwide

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    Agricultural sector PV market assessments conducted in the Phillippines, Nigeria, Mexico, Morocco, and Colombia are extrapolated worldwide. The types of applications evaluated are those requiring less than 15 kW of power and operate in a stand alone mode. The major conclusions were as follows: PV will be competitive in applications requiring 2 to 3 kW of power prior to 1983; by 1986 PV system competitiveness will extend to applications requiring 4 to 6 kW of power, due to capital constraints, the private sector market may be restricted to applications requiring less than about 2 kW of power; the ultimate purchase of larger systems will be governments, either through direct purchase or loans from development banks. Though fragmented, a significant agriculture sector market for PV exists; however, the market for PV in telecommunications, signalling, rural services, and TV will be larger. Major market related factors influencing the potential for U.S. PV Sales are: lack of awareness; high first costs; shortage of long term capital; competition from German, French and Japanese companies who have government support; and low fuel prices in capital surplus countries. Strategies that may aid in overcoming some of these problems are: setting up of a trade association aimed at overcoming problems due to lack of awareness, innovative financing schemes such as lease arrangements, and designing products to match current user needs as opposed to attempting to change consumer behavior

    Optical properties of Mn4+ ions in GaN:Mn codoped with Mg acceptors

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    The optical properties of Mn-Mg codoped epitaxial GaN were studied. Addition of Mg acceptors quenches the weak manganese-related photoluminescence (PL) band at 1.3 eV in GaN:Mn and a series of sharp PL peaks are observed at 1 eV in codoped epilayers. The change in PL spectra indicates that Mg addition stabilizes the Mn4+ charge state by decreasing the Fermi level. The 1 eV PL peaks are tentatively attributed to intra center transitions involving Mn4+ ions. Spin allowed 3d-shell 4T2-4T1 transitions and their phonon replicas are involved. The relative intensities of the sharp peaks are strongly dependent on the excitation wavelength, indicating the optically active Mn4+ centers involved in the separate peaks are different. The temperature dependence of the PL spectrum suggests the presence of at least three distinct Mn4+ complex centers.Comment: 14 pages, 3 figures, 1 table, accepted by Appl. Phys. Let

    Finding renewal in the midst of disaster: The case of the deepwater horizon oil spill

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    In 2010, the United States experienced the worst environmental disaster in its history. An explosion on a BP oilrig located in the Gulf of Mexico triggered the crisis. As a result, the United States coast guard and BP were charged with crisis communication in its response to the crisis. This essay provides an unprecedented examination and analysis of the communication experiences of public information officers who worked in the unified command center in Houma, Louisiana during the Deepwater Horizon oil spill response. The authors use the discourse of renewal theory to understand the communication practices and choices of the public information officers. Then, using the renewal framework, the authors present three implications for improving crisis communication research and practice

    Tidal scattering of stars on supermassive black holes in galactic centers

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    Some of the mass that feeds the growth of a massive black hole (BH) in a galactic center is supplied by tidal disruption of stars that approach it on unbound, low angular momentum orbits. For each star that is disrupted, others narrowly escape after being subjected to extreme tidal distortion, spin-up, mixing and mass-loss, which may affect their evolution and appearance. We show that it is likely that a significant fraction of the stars around massive BHs in galactic centers have undergone such extreme tidal interactions and survived subsequent total disruption, either by being deflected off their orbit or by missing the BH due to its Brownian motion. We discuss possible long-term observable consequences of this process, which may be relevant for understanding the nature of stars in galactic centers, and may provide a signature of the existence of massive BHs there.Comment: 5 pages 4 figures. ApJL in press, minor changes to reflect journal version including redifinition of unbound tidally disturbed stars and additional reference
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