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91.
Previous research indicates that the use of impression management is related to supervisor ratings of employee likeability and job performance. It has been argued, though, that employees might also use impression management so that their superiors will see them as ‘good soldiers’ who engage in high levels of organizational citizenship behaviors (OCBs). This study investigates the ways in which three types of impression management—namely, job‐focused, self‐focused, and supervisor‐focused tactics of impression management—influence supervisor ratings of OCB. Using a sample of 122 supervisor‐subordinate dyads, the findings indicate that supervisor‐focused tactics of impression management are positively related to OCB ratings, while job‐focused tactics are negatively related to such evaluations. Additionally, citizenship behaviors are positively related to supervisor liking of the employee and overall ratings of job performance. Finally, the results suggest that OCB ratings mediate the relationship between supervisor‐focused tactics of impression management and supervisor evaluations of employee likeability. Some implications of this study and directions for future research are also addressed. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
92.
On the response of 500 gal propane tanks to a 25% engulfing fire   总被引:1,自引:0,他引:1  
This paper presents detailed data on the thermal response of two 500 gal ASME code propane tanks that were 25% engulfed in a hydrocarbon fire. These tests were done as part of an overall test programme to study thermal protection systems for propane-filled railway tank-cars.

The fire was generated using an array of 25 liquid propane-fuelled burners. This provided a luminous fire that engulfed 25% of the tank surface on one side. The intent of these tests was to model a severe partially engulfing fire situation.

The paper presents data on the tank wall and lading temperatures and tank internal pressure. In the first test the wind reduced the fire heating and resulted in a late failure of the tank at 46 min. This tank failed catastrophically with a powerful boiling liquid expanding vapour explosion (BLEVE). In the other test, the fire heating was very severe and steady and this tank failed very quickly in 8 min as a finite rupture with massive two-phase jet release. The reasons for these different outcomes are discussed. The different failures provide a range of realistic outcomes for the subject tank and fire condition.  相似文献   

93.
This paper describes the results from a series of fire tests that were carried out to measure the effect of defects in thermal protection systems on fire engulfed propane pressure vessels.

In North America thermal protection is used to protect dangerous goods rail tank-cars from accidental fire impingement. They are designed so that a tank-car will not rupture for 100 min in a defined engulfing fire, or 30 min in a defined torching fire. One common system includes a 13 mm blanket of high-temperature ceramic fibre thermal insulation covered with a 3 mm steel jacket. Recent inspections have shown that some tanks have significant defects in these thermal protection systems. This work was done to establish what levels of defect are acceptable from a safety standpoint.

The tests were conducted using 1890 l (500 US gallon) ASME code propane pressure vessels (commonly called tanks in the propane industry). The defects tested covered 8% and 15% of the tank surface. The tanks were 25% engulfed in a fire that simulated a hydrocarbon pool fire with an effective blackbody temperature of 870 °C.

The fire testing showed that even relatively small defects can result in tank rupture if the defect area is engulfed in a severe fire, and the defect area is not wetted by liquid from the inside. A wall failure prediction technique based on uniaxial high-temperature stress rupture test data has been developed and agrees well with the observed failure times.  相似文献   

94.
In two role‐playing scenarios, we investigate how White male and female evaluators perceive an Asian American versus White job candidate on the dimensions of competence and social skills and how these perceptions affect evaluators' decisions in hiring and promotion. Specifically, Study 1 examines how the perceptions of competence and social skills affect Asian (versus White) college graduates' chance of obtaining a non‐technical (versus technical) position, and Study 2 tests how these perceptions affect Asians' probability of promotion relative to Whites'. Our findings suggest that female evaluators were less likely to select Asian than White candidates into positions involving social skills and were less likely to promote Asian than White candidates into these types of positions. Furthermore, female evaluators' perception that Asians were less socially skilled than Whites mediated both of these decisions. This paper contributes to the understanding of workplace discrimination of Asian Americans. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
95.
In recent years, there has been increasing interest in positive organizational scholarship in general, including positive organizational behavior (POB) in particular. This work identifies organizational citizenship behavior (OCB) as a prototypical POB. Conceptualizing OCBs in this way is sensible in light of more than 30 years of research highlighting the desirable aspects of such behavior. At the same time, some researchers have raised questions about positive organizational scholarship and have called for a more balanced view of ostensibly positive behaviors. The purpose of this paper, then, is to take a more nuanced view of OCBs while highlighting the dark side of citizenship behavior. In doing so, we review conceptual and empirical work that has challenged the idea that OCBs are inherently positive. We also discuss research that seeks to develop a deeper understanding of the conditions under which OCB does more harm than good. Finally, important areas for future research and the practical realities facing scholars who seek to publish research investigating the dark side of citizenship are addressed as well. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
96.
97.
This study compares highway crash incidence, injuries, and costs by vehicle type. Annual crash and injury incidence were estimated using Crashworthiness Data System (1988-1991), National Automotive Sampling System (1982-1986), General Estimates System (1992-1993), and Fatal Analysis Reporting System (1993) data. Costs were computed based on restraint use, body region, and threat-to-life severity of the injury. Costs were then allocated between vehicle types using three different methods in order to answer comparative safety questions. Motor vehicle and bicycle crash costs total $389 billion annually; 75% resulting from passenger vehicles. Motorcycles and bicycles have the highest costs per 1000 vehicle and passenger miles; costs per victim are highest for pedestrians, bicyclists, and motorcyclists. Costs per vehicle mile for heavy trucks and passenger cars are comparable but exceed costs for light trucks. Passenger vehicle occupants are safest if a crash occurs. Light truck, other single truck, and bus occupants have the lowest cost per passenger mile, but higher costs than air and rail travelers. Motorcyclists face the greatest risks. Combination trucks may not impose an excess risk to other drivers, but their drivers face large risks.  相似文献   
98.
This study analyzes 46 brain and 48 spinal-cord impact experiments. The velocity of brain impact was 2.0-10.0 m/s and displacement, 0.75-5.0 mm (5.3-33% compression) using a controlled pneumatic impact. The velocity of spinal-cord impact was 1.5-6.0 m/s and displacement, 1.25-3.25 mm (25-65% compression). Brain injury varied from cortical contusion, diffuse axonal injury (DAI), to fatalities, and spinal-cord injury from temporary to complete loss of somatosensory-evoked potentials. Logist functions were determined for each injury severity and various biomechanical parameters, VC, C, V, and combinations. Brain and spinal-cord injury is most strongly correlated to VC, the viscous response. The goodness-of-fit was x2 = 22.1, R-0.84 and p< 0.0000 for fatal brain injury, x2 = 27.5, R = 0.96 and p< 0.0000 for cortical contusion, and x2 = 17.7, R = 0.49 and p < 0.0001 for partial recovery of spinal-cord conduction. Neural tissue is viscoelastic, with a rate-dependent tolerance related to energy absorption. VC is a measure of energy absorption by impact deformation and is predictive of neural contusion, DAI, long-duration coma, spinal-cord dysfunction, and death. Tolerances for various severities of neural injury are presented. At the tissue level, VC is the product of strain and strain-rate, ε dε/dt. The research shows that strain is not a sufficient parameter of neural injury risk, and that the product of strain and strain-rate is a key biomechanical parameter for brain and spinal-cord injury.  相似文献   
99.
This article is a brief review of the mechanism of action of fibrous filters and of the performance of respirators; it neglects many of the complications discussed in longer and more detailed articles. An expression is given for the pressure drop across a filter in terms of fibre diameter and filtration velocity. The particle capture mechanisms of interception and diffusional deposition are introduced and the way in which filtration efficiency varies with particle size is discussed. Filters with fibres of small diameter are shown to be the most efficient, but their use can cause problems. Electrically charged materials are widely used in respirators because of their high efficiency and low pressure drop. Types of material, their means of charging, and their method of action are described. An account is given of respirator leakage, the protection factor, and of the way that these may vary in a period of use. The leakage of air and particles through face seal leaks and leaky valves is discussed. The frequent discrepancy in the protection given by respirators in the workplace, on the one hand, and that suggested by laboratory measurements, on the other, is reviewed, and the article ends with an account of the combined effect of aerosol penetration through a filter and through a leak.  相似文献   
100.
The aim of the work is to outline a procedure of finding force-velocity (F–V) characteristics (F = f(V)) of individual skeletal muscles of the human locomotor system. The presentation is based on an example concerning extensors of the elbow joint: the lateral and long heads of triceps brachii (TBCIat and TBCIong). The experimental part of the procedure involves a natural movement of using the upper extremity to push an external object of variable, adjustable load, engaging both the elbow and shoulder joint.

Five men aged 23 took part in the experiment. Their task was to push the handle of a physical pendulum whose moment of inertia could be adjusted within the range of 58 kg m2-450 kg m2, so as to give it maximum angular velocity. During each trial the movement of the trunk, of the upper extremity and of the pendulum was video recorded and the force applied with the hand to the handle of the pendulum was measured.

In order to find the F–V characteristics a simulation model SHOULDER was used, which is capable of solving the synergy problem for muscles of the arm and the shoulder girdle.

It was found that despite considerable dispersion of experimental points the respective regression lines revealed a clear tendency of decreasing muscle force for increased shortening velocity of the monoarticular head (TBCIat) and of increasing muscle force for increased lengthening velocity of the biarticular head (TBCIong) of the triceps brachii muscle.  相似文献   
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