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961.
KB Smith 《Surface Coatings International Part B: Coatings Transactions》1997,80(12):573-576
Summary & Conclusions The goniphotometer/glossmeter based on the LDA detector has been developed into a portable and robust instrument with exceptionally
high resolution of the light distribution near the specular angle.
The LDA detector combined with the read-out circuitry and associated software made it possible to select the appropriate sets
of photodiode sensors to calculate indices of peak specular reflectance; gloss; haze and distinctness of image. The data,
including full reflected light distribution curves, can be stored and subsequently downloaded to a computer for display or
analysis. 相似文献
962.
This paper compares the occurrence of rheumatic complaints among male engine drivers with their body measurements and with the dimensions of the cab in the Rc Swedish engine. 150 Swedish engine drivers were interviewed regarding symptoms from the musculoskeletal system. Relevant anthropometric measurements were obtained from each subject and compared with similar dimensions on a symptom free group of drivers matched for age. Data concerning the dimensions of the cab in the Rc engine were obtained from drawings and measurements of the cab. The results indicate that engine drivers with complaints in the lower back, neck and/or shoulders and/or the lower extremities were significantly shorter than controls in those anthropometric measurements related to correct sitting posture. Since the cab of the Rc engine is designed for tall engine drivers, the shorter driver appears to be at risk. Recommendations for cab designs suitable for all potential male and female drivers are appended. 相似文献
963.
The present study is focused on swirl motion in a top blown water model, where a deep water swirl motion is observed. During the experiments, the top lance, with cylindrical nozzles, was placed above the water surface and thereby produced an external force on the bath. The effect on how different parameters, such as nozzle diameter and the distance between the bath surface and nozzle exit, i.e. the lance height, affect the swirl motion were studied. More specifically, the amplitude and period of the swirl as well as the starting and damping time of the swirl were determined. The amplitude was found to increase with an increased nozzle diameter and gas flow, while the period had a constant value of about 0.5 s for all nozzle diameters, gas flows and lance heights. The starting time for the swirl motion was found to decrease with an increased gas flow, while the damping time was found to be independent of gas flow rate, nozzle diameter, lance height and ratio of depth to diameter. 相似文献
964.
A static modelling approach was used to study the growth and removal of inclusions during gas stirring in a ladle. A mathematical model of a gas‐stirred ladle was used to predict the data necessary to calculate growth and removal of inclusions. Results indicated that inclusion growth resulting from laminar shear collisions is negligible in comparison with growth from turbulent and Stokes collisions. Furthermore, the need for a model describing inclusion flotation by spherical‐cap bubbles was identified. Since the existing models presented in the literature are only valid for spherical bubbles, a model for the removal of inclusions by spherical‐cap bubbles was developed. Inclusion removal to the slag, refractory and by bubble flotation was compared. The mechanism determined to be responsible for the removal of the majority of inclusions larger than 25 μm was Stokes flotation and for the majority of the smaller inclusions, bubble flotation by spherical‐cap bubbles (assuming plane contact between the inclusion and the bubble). 相似文献
965.
This paper examines how fluxes in the aquatic environment reflect the reduced use of cadmium (Cd) and lead (Pb) in Stockholm, Sweden, between 1975 and 1995. The sediment deposition of Cd and Pb in the waters around Stockholm was investigated using laminated sediment cores, which facilitated reconstructions of historical annual metal deposition to the sediments. The resulting reconstructions were compared to independent estimations of the emissions to the aquatic environment during the phase-out period. The loads of Cd and Pb from sewage treatment plants, storm water and in atmospheric deposition were studied using literature data. The data set indicates a reduced load of Cd and Pb on the aquatic surroundings of Stockholm. The reduction is, however, not as pronounced in the sediment deposition as in the calculated emissions. This indicates that emissions may be delayed on their way to the sediments or that there are other sources, e.g. resuspension of older sediments. It is therefore argued that sediment investigations are an essential component in environmental monitoring, in order to get a complete picture of the metal fluxes to and in the environment in urban areas. 相似文献
966.
JL Brodsky ED Werner ME Dubas JL Goeckeler KB Kruse AA McCracken 《Canadian Metallurgical Quarterly》1999,274(6):3453-3460
Polypeptide import into the yeast endoplasmic reticulum (ER) requires two hsp70s, Ssa1p in the cytosol and BiP (Kar2p) in the ER lumen. After import, aberrant polypeptides may be exported to the cytoplasm for degradation by the proteasome, and defects in the ER chaperone calnexin (Cne1p) compromise their degradation. Both import and export require BiP and the Sec61p translocation complex, suggesting that import and export may be mechanistically related. We now show that the cne1Delta and two kar2 mutant alleles exhibit a synthetic interaction and that the export and degradation of pro-alpha factor is defective in kar2 mutant microsomes. Pulse-chase analysis indicates that A1PiZ, another substrate for degradation, is stabilized in the kar2 strains at the restrictive temperature. Because two of the kar2 mutants examined are proficient for polypeptide import, the roles of BiP during ER protein export and import differ, indicating that these processes must be mechanistically distinct. To examine whether Ssa1p drives polypeptides from the ER and is also required for degradation, we assembled reactions using strains either containing a mutation in SSA1 or in which the level of Ssa1p could be regulated. We found that pro-alpha factor and A1PiZ were degraded normally, indicating further that import and export are distinct and that other cytosolic factors may pull polypeptides from the ER. 相似文献
967.
Dementia due to cerebral ischemic lesions is relatively common in the elderly. Since many of these lesions are probably caused by emboli, studying emboli-induced cerebral lesions in rabbits should, hopefully, provide information that is useful when searching for a means of preventing and treating vascular dementia in humans. Using magnetic resonance imaging we have found that N-tert-butyl-alpha-phenyl-nitrone (a free radical scavenger) reduced the number of emboli-induced cerebral microinfarctions in the rabbit cortex but did not have any impact on the number of infarctions found in the subcortical structures. The results suggest that significant amount of free radicals are produced in the ischemic foci located in the cortex, but not in the ischemic foci located in the subcortical structures. This finding may be of importance when considering treatments for cerebral ischemia in humans. 相似文献
968.
M Conconi L Djavadi-Ohaniance W Uerkvitz KB Hendil B Friguet 《Canadian Metallurgical Quarterly》1999,362(2):325-328
Proteasomes interact with a variety of macromolecular ligands that modulate their ability to degrade peptide and protein substrates. The effector PA28 increases the peptidase activities of proteasomes whereas HSP90 and alpha-crystallin inhibit a peptide-hydrolyzing activity. Four monoclonal antibodies were used as probes to detect conformational changes of proteasome subunits. Conformational changes in alpha- or beta-subunits were found upon binding PA28, HSP90, alpha-crystallin, and the substrate casein but not with the peptide substrate analogs calpain inhibitor 1 (Ac-Leu-Leu-norleucinal), calpain inhibitor 2 (Ac-Leu-Leu-methioninal), or MG 132 (N-Cbz-Leu-Leu-leucinal). 相似文献
969.
Experimental data from a study using a landfill simulation reactor were used to develop and calibrate a one-dimensional distributed model of co-digestion of municipal solid waste and three phthalic acid diesters with different water solubilities. The three diesters were diethyl phthalate, dibutyl phthalate, and di-2-ethylhexyl phthalate. Two types of municipal solid wastes were assumed, easily degradable and recalcitrant. The model considered inhibition of hydrolysis of the recalcitrant fraction and phthalic acid esters, and also methanogenesis at acidic pH. The results indicated that the prolonged steady-state concentrations of the diesters in the leachates could be explained by equilibrium between physicochemical desorption and sorption processes for the three diesters. When methanogenic conditions were induced in the acidogenic landfill simulation reactor, inhibition of both hydrolysis of recalcitrant MSW and of phthalic acid esters ceased. 相似文献
970.
Mark I. Howells Sandra Jonsson Emilia Käck Philip Lloyd Kevin Bennett Tony Leiman Beatrice Conradie 《Energy Policy》2010
This paper describes how management and information failures can retard transitions from the traditional use of biomass fuel by low income rural consumers and micro-producers. 相似文献