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51.
Paul Geoerg Florian Berchtold Steven Gwynne Karen Boyce Stefan Holl Anja Hofmann 《火与材料》2019,43(7):759-781
To quantify the evacuation process, evacuation practitioners use engineering egress data describing the occupant movement characteristics. These data are typically based to young and fit populations. However, the movement abilities of occupants who might be involved in evacuations are becoming more variable—with the building populations of today typically including increasing numbers of individuals: with impairments or who are otherwise elderly or generally less mobile. Thus, there will be an increasing proportion of building occupants with reduced ability to egress. For safe evacuation, there is therefore a need to provide valid engineering egress data considering pedestrians with disabilities. Gwynne and Boyce recently compiled a series of data sets related to the evacuation process to support practitioner activities in the chapter Engineering Data in the SFPE Handbook of Fire Protection Engineering. This paper supplements these data sets by providing information on and presenting data obtained from additional research related to the premovement and horizontal movement of participants with physical‐, cognitive‐, or age‐related disabilities. The aim is to provide an overview of currently available data sets related to, and key factors affecting the egress performance of, mixed ability populations which could be used to guide fire safety engineering decisions in the context of building design. 相似文献
52.
Jari Kolehmainen Ali Ozel Christopher M. Boyce Sankaran Sundaresan 《American Institute of Chemical Engineers》2017,63(6):1872-1891
To investigate the interplay between particle charging and hydrodynamics in fluidized beds, models for triboelectric charging and electrostatic forces were built into a computational fluid dynamics‐discrete element method model. Charge transfer was governed by the difference in effective work function between contacting materials as well as the electric field at the point of contact. Monodisperse particles were fluidized with an effective work function difference between the particles and the conducting walls. For smaller work function differences, hydrodynamics were not changed significantly as compared with an uncharged case. In these simulations, the average charge saturated at a value much lower than the value anticipated based on the work function difference, and a unimodal distribution of charges was observed. For larger work function differences, particles stuck to walls and bed height oscillations due to slugging were less pronounced. For these cases, a bimodal distribution of charges emerged due to effects from strong electric fields. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1872–1891, 2017 相似文献
53.
The introduction of carbon charges on the use of fossil fuels in China would have a progressive impact on income distribution. This outcome, which contrasts to the regressive distributional impact found in most studies of carbon charges in industrialized countries, is driven primarily by differences between urban and rural expenditure patterns. If carbon revenues were recycled on an equal per capita basis via a ‘sky trust,’ the progressive impact would be further enhanced: low-income (mainly rural) households would receive more in sky-trust dividends than they pay in carbon charges, and high-income (mainly urban) households would pay more than they receive in dividends. Thus a Chinese sky trust would contribute to both lower fossil fuel consumption and greater income equality. 相似文献
54.
55.
Kenneth Boyce 《世界电子元器件》2009,(5):47-50
概述随着手持语音通信设备越来越流行,它们应用在嘈吵环境的机会也越来越高,例如机场、交通繁忙的路段、人多嘈杂的酒吧等。在这种嘈吵的环境下,通话的双方实在难以听清对方所说的话。 相似文献
56.
Oxygen Tracer Diffusion in Vitreous Silica 总被引:2,自引:0,他引:2
Joseph D. Kalen Rethia S. Boyce James D. Cawley 《Journal of the American Ceramic Society》1991,74(1):203-209
Oxygen diffusion in vitreous silica glass is studied using the gas exchange technique. The tracer concentration profiles are consistent with a model based on two mechanisms, one network and the other interstitial. These processes are coupled through limited network–interstitial exchange. Nuclear reaction analysis and secondary ion mass spectrometry techniques are performed and compared. These results are compared to experiments on transport in thin silica films grown on single-crystal silicon. 相似文献
57.
A clinical study of hand strength and complications in 41 patients with a transmetacarpal amputation of the index finger found that the average prehension strength was reduced by 20% and stability of grip by almost 50%. Tendon transfers or other operative modifications did not affect the results. The most disabling complication, hyperesthesia, or painful sensitivity to light touch, in the thumb--long-finger web was present in 59% of patients and interfered with hand function in 37%. 相似文献
58.
R Rabinowitz M Barkin JF Schillinger RD Jeffs GT Cook 《Canadian Metallurgical Quarterly》1977,118(3):436-439
Bypass of the left ventricle was accomplished in dogs and the entire circulation was supported temporarily by only the right ventricle. The atrial septum was excised, and the atrium was repartitioned so that the pulmonary veins were in continuity with the right ventricle and the venae cavae were connected through the atrium. Anastomosis of the superior vena cava to the right pulmonary artery brought systemic venous return directly to the lungs. The main pulmonary artery was ligated proximal to the bifurcation, preserving distal confluence of right and left pulmonary arteries. A tubular prosthesis between the proximal pulmonary artery and the aorta connected the right ventricle to the systemic circuit. This procedure, or some modification of the principle, may have clinical feasibility in the treatment of patients with hypoplastic left heart syndrome. 相似文献
59.
A Berdeaux A Batisse C Richer J Kachaner JF Giudicelli 《Canadian Metallurgical Quarterly》1977,6(24):2142-2144
Measurement of plasma digoxin concentrations in infants after three increasing dosage levels shows that the optimal dose of this glycoside in 20 microgram/kg/day, i.e. a loading dose of 20 microgram/kg followed every 8 hours by a maintenance dose of 7 microgram/kg. The plateau concentration achieved is 3.0 +/- 0,5 ng/ml 8 hours after the last administration. When digoxin levels exceed 5 ng/ml (overdosage, renal failure or low body weight), toxic manifestations occur. 相似文献
60.
Movement of the cervical spine in the sagittal plane was studied in ten normal subjects from 20 to 30 years of age without and with four different cervical orthoses: (1) polyethylene Camp plastic collar with chin and occiput piece, (2) plastizote Philadelphia collar, (3) four-poster and (4) SOMI (sternal occipital mandibular immobilization). The effect of the orthoses on restricting sagittal motion was measured simultaneously using roentgenographic and bubble goniometric methods. The subject was immobilized in a straight back chair to eliminate trunk motion, and lateral cervical spine films were taken of each subject in neutral, flexion and extension without and with each orthotic device. Distortion forces exerted on the orthotic devices were standardized by measurement of pressures at the chin and occiput. Roentgenographic measurements of flexion and extension and anteroposterior displacement of the cervical spine were compared to the measurements obtained by bubble goniometry. The four-poster and SOMI were found to be most effective in restricting extension and flexion respectively. The polyethylene and plastizote orthoses were significantly less effective in restricting motion. The bubble goniometer is an adequate clinical tool in assessing overall flexion-extension of the cervical spine but is not so precise and does not give information on the degree of motion at an individual vertebral level. 相似文献