7,023 research outputs found

    Carbon-13 nuclear magnetic resonance spectra and mechanism of bridgeā€“terminal carbonyl exchange in di-Āµ-carbonyl-bis[carbonyl(Ī·-cyclopentadienyl)iron](Feā€“Fe)[{(Ī·-C5H5)Fe(CO)2}2]; cd-di-Āµ-carbonyl-f-carbonyl-ae-di(Ī·-cyclopentadienyl)-b-(triethyl -phosphite)di-iron(Feā€“Fe)[(Ī·-C5H5)2Fe2(CO)3P(OEt)3], and some related complexes

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    A mechanism involving carbonyl-bridge breaking, rotation about the Feā€“Fe bond, and bridge reformation is shown to account qualitatively for changes in the carbonyl region of the 13C n.m.r spectrum of the complex [(cp)(OC)[graphic omitted]e(cp){P(OEt)3}] and quantitatively for [(cp)(OC)[graphic omitted]e(CO)(cp)](cp =Ī·-cyclopentadienyl).The activation energy for this process, 49.0 Ā± 4 kJ mol^ā€“1(11.7 Ā± 1 kcal mol^ā€“1), is close to that reported for cisā€“trans-isomerization of the cp groups, in accord with this mechanism. Variable-temperature 13C n.m.r. spectra of the complexes [(cp)(OC)[graphic omitted]u(CO)(cp)] and [(cp)(OC)[graphic omitted]i(cp)] are also reported

    The Adoption of Lean Operations and Lean Accounting on the Financial-Performance Measures of Publicly Traded Companies

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    For fiscal years 2008 through 2010, manufacturers and service providers that adopted lean operations outperformed companies that did not adopt lean operations. Using non-parametric tests and a matched-pairs design, lean companies had greater returns on both net operating assets (RNOA) and total assets (ROA). Lean companies also experienced better operating cash flows and cash adequacy than non-lean companies. The profit margins and financing-assets ratios were marginally better for lean companies than non-lean companies. Several working-capital measures, however, were not significantly different. Lean companies also experienced higher total-inventory turnover and raw-materials inventory turnover than non-lean companies. Although work-in-process inventory turnover did not differ significantly between the two groups, the test for that hypothesis contained the fewest number of matched pairs due to fewer companies reporting values for work-in-process. Lean companies experienced lower days\u27-sales in inventory and marginally higher finished-goods inventory turnover than non-lean companies

    Optical and Thermal Properties of Spinel with Revised (Increased) Absorption at 4 to 5 Ī¼M Wavelengths and Comparison with Sapphire

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    Infrared absorption of high-quality, commercial, polycrystalline MgAl2O4 spinel is āˆ¼40% greater in the range of 3.8 to 5.0 Ī¼m than the value predicted by the computer code OPTIMATRĀ®, which has been used for window and dome design for more than 20 years. As a result, spinel and a-plane sapphire windows designed to support the same external pressure with the same probability of survival have approximately the same infrared absorptance in the range 3.8 to 5.0 Ī¼m. c-Plane sapphire has greater absorptance than spinel in the range 3.8 to 5.0 Ī¼m. Spinel has two weak absorption bands near 1.8 and 3.0 Ī¼m. At 1.064 Ī¼m, the laser calorimetric absorption coefficient of spinel is 10 to 50 times greater than that of sapphire. New measurements of specific heat capacity, thermal expansion, thermal conductivity, elastic constants, and refractive index (including dnāˆ•dT) of spinel are reported

    The Effect of Emotional Intelligence and Task Type on Malevolent Creativity

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    Malevolent creativity (MC), or intending to inflict harm in original ways, is an aspect of creativity that has received little empirical attention. It reasons that generating malevolently creative products in response to a problem is dependent upon individual differences and environmental factors, especially with regard to the social and emotional content of a particular problem. A personality variable strongly associated with how individuals acknowledge and respond to such social and emotional content is emotional intelligence (EI). Individuals with higher EI often solve problems in cooperative, beneficial, and positive ways, which seems contrary to solving a problem with MC. In addition to testing whether EI is negatively related to MC in general, we analyzed whether that negative relationship would persist even after controlling for cognitive ability and task effects. Those questions were examined across two studies. Results suggest that individuals with lower EI are more likely to respond to different types of problems with increased instances of MC even when the social or emotional content of those problems are factored out. The implications and limitations of these studies, as well as future directions for the study of MC, are discussed

    Revisions of Extensive Acetabular Defects with Impaction Grafting and a Cement Cup

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    Item does not contain fulltextBACKGROUND: Loosening of acetabular components often leads to bony defects. Management of extensive acetabular bone loss in hip revision arthroplasty can be a tremendous challenge. QUESTIONS/PURPOSES: We asked whether a reconstruction with impacted bone grafts will provide a durable and pain-free function in extensive acetabular defects. We specifically determined the (1) survival rates with the end point of revision for any reason, aseptic revision, and radiographic loosening; (2) visual analog scale (VAS) pain score, Harris hip score (HHS), and the Oxford Hip Questionnaire score (OHQS); (3) number of repeat revisions; (4) complications; and (5) radiographic loosening, wear, and radiolucencies. PATIENTS AND METHODS: We retrospectively followed 25 patients (27 hips) with extensive acetabular defects. No patient was lost to followup. Two patients died during followup. Minimum followup was 3 years (mean, 8.8 years; range, 3-14.1 years). RESULTS: Three patients (three hips) underwent repeat revision surgery and another two patients (two hips) had radiographically loose hips. The 10-year survival rate was 88% (95% confidence interval, 74.2%-100%) with the end point acetabular revision for any reason and 95% (95% confidence interval, 86.0%-100%) with the end point acetabular revision for aseptic loosening. The mean HHSs were 55 points before surgery and 72 points postoperatively. CONCLUSIONS: Acetabular reconstruction with impaction bone grafting and a cemented cup is a reliable technique with a 10-year survival rate of 88% in patients with extensive acetabular deficiencies. LEVEL OF EVIDENCE: Level IV, case series. See the Guidelines for Authors for a complete description of levels of evidence
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