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Test Apparatus (test + apparatus)
Selected AbstractsA NEW TEST APPARATUS AND METHOD FOR FRICTION FORCE MEASUREMENT IN JOURNAL BEARINGS UNDER DYNAMIC LOADING: Part IEXPERIMENTAL TECHNIQUES, Issue 5 2005A. Biyiklio No abstract is available for this article. [source] Effectiveness of very thin soil layers in chemical release from bed sedimentENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2001Bryan Talbert The chemical containment effectiveness of both the natural recovery and the "particle broadcasting" processes for remediating contaminated bed-sediments depend upon very thin soil and/or sand layers millimeters in depth. Conventional capping for in situ chemical containment of bed-sediment or dredged material typically involves thick layers of 30 to 90 centimeters in depth. Few studies have been conducted with thin layers of candidate natural materials. A steady-state benzoic acid dissolution test apparatus and procedure, devised to realistically simulate bed-sediment chemo-dynamic conditions, was used to measure chemical flux through thin layers (1 to 8 mm) of soil, sand, and ideal porous media. The thin layers were found to be very effective. Flux reductions ranged from 81 to 96%, with fine sand being slightly better than top soil. Design algorithms developed for the thick layers used in conventional capping design will under predict the flux through very thin layers. Advective flow induced by surface roughness is proposed to explain the higher average measure d-to-predicted flux ratio of 1.67. [source] Comparison of flame spread of textiles and burn injury prediction with a manikinFIRE AND MATERIALS, Issue 6 2005Rene M. Rossi Abstract The flame propagation rate of 94 different natural and synthetic fabrics and commercially available garments was assessed using the EN 1103 bench scale test apparatus. To further evaluate the potential burn hazard, the fabrics were then formed into upper garments, put on a full-scale manikin equipped with 122 heat flux sensors and ignited with a small flame. By using a burn prediction model, the time to feel pain on the human skin as well as the time to suffer second degree burns could be calculated. The bench scale and full-scale test data measurements show that the flame propagation rate is inversely proportional to the fabric weight for cellulose materials. The fabrics with the highest flame propagation rates were also the garments with the shortest times to pain and to second degree burns on the manikin. However, some blends of natural and synthetic fibres gave short pain and burn times on the manikin, even when the measured flame propagation rate using EN 1103 was low. Therefore, the flame propagation rate is a good means to predict the potential hazard of fabrics made of natural fibres; for synthetics and blends of natural and synthetic fibres, the heat transfer to the skin has to be considered as well. Copyright © 2005 John Wiley & Sons, Ltd. [source] Effects of polyethylene colour and thickness on grass silage qualityGRASS & FORAGE SCIENCE, Issue 3 2003H. G. J. Snell Abstract The aim of the investigation was to determine the influence of variations in thickness and colour of agricultural plastic film on silage preservation conditions and grass silage quality. For this purpose, 30 cylindrical plastic containers (mini-silos; 0·3 m3) were filled with chopped grass and covered with five films of different thickness and colour: 90 ,m, white; 125 ,m, green; 150 ,m, black; 200 ,m, green and 200 ,m, white. Four replications of each film type were placed in the open air. Two replications were housed indoors and exposed to an ,artificial sky' in a test apparatus. The surface temperature of the films was found to be strongly dependent on film thickness and colour. Results of the chemical analysis of silages did not reveal any significant influence of the films. This was also the case when restricting the analysis to the uppermost silage layer. The results showed that under the conditions of this experiment, well preserved forage can be produced with films of differing colour, as well as of lesser thickness. [source] Occlusal contact area (OCA) wear of two new composite restorativesJOURNAL OF ORAL REHABILITATION, Issue 2 2002A. U. J. Yap The occlusal contact area wear resistance of two new composite restoratives (Z250 and P60) was investigated and compared with two existing materials (Silux and Z100) using a reciprocal compression-sliding test apparatus. Six wear specimens were made for each material and subjected to wear testing at 20 MPa with artificial saliva as lubricant. Wear depth (,m) was measured using profilometry every 20 000 cycles up to 120 000 cycles. Results were analysed using ANOVA/Scheffe's test (P < 0·05) and Pearson's correlation. The effects of cyclic loading on wear and counter-body loss were material dependent. Silux had the lowest wear at all cyclic intervals. At 20 000 and 40 000 cycles, Silux had significantly less wear than all the other composites evaluated, and Z100 had significantly less wear than Z250 and P60. After 60 000 cycles, significant differences in wear was observed only between Silux and the other composites. Correlation between number of cycles and wear/counter-body loss, and between wear and counter-body were significant and positive. The microfilled composite Silux had significantly better OCA wear resistance than the minifilled composites Z100, Z250 and P60. [source] Modifications to improve the accuracy of a four-ball test apparatusLUBRICATION SCIENCE, Issue 1 2000P. I. Lacey Abstract The four-ball wear test machine is one of the most widely used tribological tools in both research and industry. In general, the test geometry is self-aligning and minimises the opportunity for random variation. Nonetheless, accurate control of the test parameters remains vital to repeatability and reproducibility. The present paper details a number of modifications to a commercially available test apparatus that have been found to improve accuracy. The applied load on some apparatus was found to vary from the correct value, probably due to frictional drag in the loading system. A feedback control loop was designed and fitted to the applied load mechanism, which resulted in significantly improved accuracy. Finally, the apparatus was fully automated, with complete computer control of all test parameters. Under this, following cleaning and assembly of the test specimens, the required test procedure could be selected from a menu of standard methods, and the computer program then adjusted the test parameters according to the method selected, greatly reducing the possibility of operator error. [source] Environmental stress cracking behavior of bottle and fiber grade poly(ethylene terephthalate) in contact with aqueous amine solutionsPOLYMER ENGINEERING & SCIENCE, Issue 10 2008Nadir de B. Sanches The environmental stress cracking (ESC) resistance of commercial virgin bottle and fiber grade poly(ethylene terephthalate) (PET) in contact with aqueous amine solutions was investigated. The ESC resistance, in terms of time to failure, was evaluated taking into account some factors, such as test temperature, molar volume (Vo) of the ESC agent, and molecular weight and degree of crystallinity (Xc) of PET. The specimens were tested in flexural mode using a constant load flexural creep test apparatus and also in tensile mode using a dynamometer. After the creep tests, the specimens were photographed with a digital camera and analyzed by scanning electron microscopy (SEM). It was found that ESC resistance was higher with the increase of ESC agent molar volume as well as with the increase of molecular weight and degree of crystallinity of PET. The highest temperature (60°C) lowered the ESC resistance of the specimens, except for the crystalline specimens in n -butylamine that exhibited a higher ESC resistance at 60°C, which can probably be attributed to the induced crystallization of the remaining amorphous phase by the plasticizing effect of n -butylamine. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source] Lesioning of Locus coeruleus Projections by DSP-4 Neurotoxin Treatment: Effect on Amphetamine-Induced Hyperlocomotion and Dopamine D2 Receptor Binding in RatsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 5 2000Jaanus Harro DSP-4 is a neurotoxin highly selective for the noradrenergic nerve terminals of the locus coeruleus projections. Data on the effect of DSP-4 treatment on amphetamine-induced hyperlocomotion are contradictory. In this study, DSP-4 (50 mg/kg) caused reduction of noradrenaline levels by 70% in the cerebral cortex and by 79% in the cerebellum. This treatment resulted in upregulation of dopamine D2 receptors in the striatum as evidenced by [3H]-raclopride binding. In an open field test, DSP-4 reduced locomotor activity. D -Amphetamine (1.5 mg/kg) caused a similar increase in locomotor activity in control and DSP-4-pretreated animals not familiar to the apparatus. However, when the rats were habituated to the test apparatus, the effect of amphetamine on horizontal activity was significantly larger in the DSP-4-pretreated animals. These data suggest that supersensitivity of D2 receptors develops after locus coeruleus denervation, but that the enhanced efficacy of amphetamine in DSP-4-treated rats is masked by neophobia. [source] | |||||||||||||