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排序方式: 共有922条查询结果,搜索用时 31 毫秒
781.
Michelle Cardoso Fred Fulton Colin McKinnon Jack P. Callaghan Michel J. Johnson 《International journal of occupational safety and ergonomics》2019,25(3):331-343
A postural evaluation of commercial licensed truck drivers was conducted to determine the ergonomic benefits of a truck seat prototype in comparison with an industry standard seat. Twenty commercially licensed truck drivers were recruited to perform a 90-min driving task. Postures were assessed using accelerometers and a backrest and seat pan pressure mapping system. Subjective discomfort measurements were monitored using two questionnaires: ratings of perceived discomfort (RPD) and the automotive seating discomfort questionnaire (ASDQ). Participants reported significantly higher discomfort scores when sitting in the industry standard seat. Participants sat with more lumbar lordosis and assumed a more extended thoracic posture when seated in the prototype. Pairing the gluteal backrest panel with the adjustable seat pan also helped reduce the average sitting pressure on both the seat pan and the backrest. The prototype provided several postural benefits for commercially certified truck drivers, as it did for a young and healthy population. 相似文献
782.
Drawing from the social cognitive theory of self‐regulation, we develop a model linking experienced incivility to emotional exhaustion and supportive behaviors via self‐blame, with observed incivility experienced by coworkers as a first‐stage moderator and trait emotional control as a second‐stage moderator. We contend that employees will experience self‐blame if they perceive themselves to be distinct targets of incivility (i.e., observed incivility experienced by others is low). Self‐blame can potentially trigger prosocial responses for improving the situation, but self‐blaming targets rarely respond in a prosocial manner because rational attempts to do so are thwarted by deleterious negative emotions accompanying self‐blame. We argue that trait emotional control provides resources for managing these negative emotions to unleash a bright side of self‐blame, such that the relation of self‐blame with prosocial responses (i.e., being supportive to coworkers) will be more positive and the relation of self‐blame with emotional exhaustion will be less positive for individuals with high (vs. low) trait emotional control. Multiwave data collected from a sample of 220 police officers largely support our hypotheses, indicating that the indirect relation of experienced incivility with supportive behaviors via self‐blame is strongest at lower levels of observed incivility and higher levels of emotional control. 相似文献
783.
Jean L. Johnson 《黑龙江环境通报》2003,23(1):6-8
Molybdenum cofactor deficiency and isolated sulfite oxidase deficiency are autosomal recessive inborn errors of metabolism with severe neurological symptoms resulting from a lack of sulfite oxidase activity. The deficiencies can be diagnosed prenatally by monitoring sulfite oxidase activity in chorionic villus sampling (CVS) tissue. In those families in which the specific defects have been identified, diagnosis can be achieved by mutation analysis or linkage studies directed at affected genes. These include MOCS1, MOCS2 or GEPH, in cases of molybdenum cofactor deficiency, or SUOX in patients with isolated sulfite oxidase deficiency. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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786.
Derek Johnson Robert Heltzel Andrew Nix Rebekah Barrow 《Journal of the Air & Waste Management Association (1995)》2017,67(3):371-388
With the advent of unconventional natural gas resources, new research focuses on the efficiency and emissions of the prime movers powering these fleets. These prime movers also play important roles in emissions inventories for this sector. Industry seeks to reduce operating costs by decreasing the required fuel demands of these high horsepower engines but conducting in-field or full-scale research on new technologies is cost prohibitive. As such, this research completed extensive in-use data collection efforts for the engines powering over-the-road trucks, drilling engines, and hydraulic stimulation pump engines. These engine activity data were processed in order to make representative test cycles using a Markov Chain, Monte Carlo (MCMC) simulation method. Such cycles can be applied under controlled environments on scaled engines for future research. In addition to MCMC, genetic algorithms were used to improve the overall performance values for the test cycles and smoothing was applied to ensure regression criteria were met during implementation on a test engine and dynamometer. The variations in cycle and in-use statistics are presented along with comparisons to conventional test cycles used for emissions compliance.
Implications: Development of representative, engine dynamometer test cycles, from in-use activity data, is crucial in understanding fuel efficiency and emissions for engine operating modes that are different from cycles mandated by the Code of Federal Regulations. Representative cycles were created for the prime movers of unconventional well development—over-the-road (OTR) trucks and drilling and hydraulic fracturing engines. The representative cycles are implemented on scaled engines to reduce fuel consumption during research and development of new technologies in controlled laboratory environments. 相似文献
787.
H. Carolyn Peach Brown Barry Smit Olufunso A. Somorin Denis J. Sonwa Johnson Ndi Nkem 《Ambio》2014,43(6):759-769
Tropical forests are vulnerable to climate-change representing a risk for indigenous peoples and forest-dependent communities. Mechanisms to conserve the forest, such as REDD+, could assist in the mitigation of climate change, reduce vulnerability, and enable people to adapt. Ninety-eight interviews were conducted in three countries containing the Congo Basin forest, Cameroon, CAR, and DRC, to investigate perceptions of decision-makers within, and responses of the institutions of the state, private sector, and civil society to the challenges of climate change. Results indicate that while decision-makers’ awareness of climate change is high, direct institutional action is at an early stage. Adaptive capacity is currently low, but it could be enhanced with further development of institutional linkages and increased coordination of multilevel responses across all institutions and with local people. It is important to build networks with forest-dependent stakeholders at the local level, who can contribute knowledge that will build overall institutional adaptive capacity. 相似文献
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789.
Prakash Karamchandani Jeremiah Johnson Greg Yarwood Eladio Knipping 《Journal of the Air & Waste Management Association (1995)》2014,64(4):453-467
The Community Multiscale Air Quality (CMAQ) modeling system Version 5.0 (CMAQv5.0) was released by the U.S. Environmental Protection Agency (EPA) in February 2012, with an interim release (v5.01) in July 2012. Because CMAQ is a community model, the EPA encourages the development of proven alternative science treatments by external scientists and developers that can be incorporated as part of an official CMAQ release. This paper describes the implementation, evaluation, and testing of a plume-in-grid (PinG) module in CMAQ 5.01. The PinG module, also referred to as Advanced Plume Treatment (APT), provides the capability of resolving sub-grid-scale processes, such as the transport and chemistry of point-source plumes, in a grid model. The new PinG module in CMAQ 5.01 is applied and evaluated for two 15-day summer and winter periods in 2005 to the eastern United States, and the results are compared with those from the base CMAQ 5.01. Eighteen large point sources of NOx in the eastern United States were selected for explicit plume treatment with APT in the PinG simulation. The results show that overall model performance is negligibly affected when PinG treatment is included. However, the PinG model predicts significantly different contributions of the 18 sources to pollutant concentrations and deposition downwind of the point sources compared to the base model.
Implications: This study describes the incorporation of a plume-in-grid (PinG) capability within the latest version of the EPA grid model, CMAQ. The capability addresses the inherent limitation of the grid model to resolve processes, such as the evolution of point-source plumes, which occur at scales much smaller than the grid resolution. The base grid model and the PinG version predict different source contributions to ozone and PM2.5 concentrations that need to be considered when source attribution studies are conducted to determine the impacts of large point sources on downwind concentrations and deposition of primary and secondary pollutants. 相似文献
790.
S. R. Milillo B. Lungu C. A. O’Bryan S. E. Dowd A. Muthaiyan M. G. Johnson 《Journal of environmental science and health. Part. B》2013,48(2):146-150
In certain environments nutrient and energy sources available to microorganisms can be limited. Foodborne pathogens must efficiently adapt in order to be successfully transmitted through the food chain to their hosts. For the intracellular foodborne pathogen Listeria monocytogenes, little is known regarding its response to nutrient/energy-limiting conditions. The alternative stress responsive sigma factor σB has been reported to contribute to survival under specific stresses. Therefore, the effects of several metabolic inhibitors on growth of L. monocytogenes wild-type and a ΔsigB mutant were examined. In the absence of inhibitors, both strains reached stationary phase after 18 h at 23°C and 10 h at 37°C. All of the metabolic inhibitors slowed growth of either strain, with few differences observed among the different inhibitors. 相似文献