Collapse test

These powders can be classified qualitatively by assigning appropriate three-digit designations, or descriptors, in accordance with the presence or absence of particular stages in the bed collapsing test, as shown in Table VI. 

Plastic collapse test in lab. of optimal model frame. high (though different specimen each time) loads — clear collapse mode - fairly clear medium - high fairly high... 

ABSTRACT Type of collapsibility of site is an important content in evaluation of loess collapsibility, the results calculated according to indoor test is often contradict with field test results. In order to solve the contradiction, the paper analyzes the factors that brings about difference in indoor and field test results based on the in-situ immersion test results in loess site completed in recent years, makes a study of the influence of discontinuous distribution of collapsible loess on collapse settlement, and presents the improved empirical formula for collapse settlement calculation under overburden pressure. The results show that indoor collapsibility test succeeds but impairs the correlation between factors such as loess property, stratum configuration, stress history, buried depth and settlement by immersion, during collapse settlement calculation, the correction of these influential factors shall be taken into consideration the standard used for judgment of loess as to whether it is collapsible may be properly heightened, in case of discontinuous distribution of collapsible loess, stress redistribution effect shall be taken into account. 

Maxwell, R. L., and R. W. Holland, Collapse Test of a Thin-Walled Cylindrical Pressure Vessel with Radially Attached Nozzle, WRC Bulletin No. 230, Welding Research Council, New York, September 1977. 

Neumann has adapted the pendant drop experiment (see Section II-7) to measure the surface pressure of insoluble monolayers [70]. By varying the droplet volume with a motor-driven syringe, they measure the surface pressure as a function of area in both expansion and compression. In tests with octadecanol monolayers, they found excellent agreement between axisymmetric drop shape analysis and a conventional film balance. Unlike the Wilhelmy plate and film balance, the pendant drop experiment can be readily adapted to studies in a pressure cell [70]. In studies of the rate dependence of the molecular area at collapse, Neumann and co-workers found more consistent and reproducible results with the actual area at collapse rather than that determined by conventional extrapolation to zero surface pressure [71]. The collapse pressure and shape of the pressure-area isotherm change with the compression rate [72]. 

Barnes and Hunter [290] have measured the evaporation resistance across octadecanol monolayers as a function of temperature to test the appropriateness of several models. The experimental results agreed with three theories the energy barrier theory, the density fluctuation theory, and the accessible area theory. A plot of the resistance times the square root of the temperature against the area per molecule should collapse the data for all temperatures and pressures as shown in Fig. IV-25. A similar temperature study on octadecylurea monolayers showed agreement with only the accessible area model [291]. 

Excessive pressure during pressure test can collapse floats and wreck level-measuring device if unit is not suitably protected. 

Although lusting is normally a slow process, it can be rapid under some conditions. Two men collapsed in an evaporator, which had contained warm, moist magnesium chloride. One of them later died. Afterward, tests showed that the oxygen content fell to 1% in 24 hours [9, 10]. Other tests showed that corrosion rates increased ten times when the relative humidity increased from 38% to 52% [11]. 

A man was asked to clean a 45-m tank that had contained toluene. It was 20 ft (6 m) tall and 10 ft (3 m) diameter. It had not been gas-freed, and the atmosphere had apparently not been tested. He entered the tank through the 16-in.-diameter top opening, using a rope for descent. Self-contained breathing apparatus was available on the job, but he did not wear it. He was overcome by tbe vapor and lack of air and collapsed on the floor of the tank. 

An 87 13 mixt with benz gave a Trauzl test of 134% of TNT (Ref 26). Mixts of from 65 to 90% by wt in benz had a card gap test of over 300 cards, indicating them to be very sens (Ref 36). The sensy of mixts with benz was found to be due to the formation and collapse of cavitation bubbles in the liq (Ref 43) Ethylene Glycol. A 50% soln by wt had a card gap test of 270 cards (Ref 36)... 

In the conclusion of the present chapter we show how comparison of NMR and Raman scattering data allows one to test formulae (3.23) and (3.24) and extract information about the relative effectiveness of dephasing and rotational relaxation. In particular, spectral broadening in nitrogen caused by dephasing is so small that it may be ignored in a relatively rarefied gas when spectrum collapse proceeds. This is just what we are going to do in the next sections devoted to the impact theory of the isotropic Raman spectrum transformation. 

If return occurs during the bromination of cw-stilbenes and rotation around the C-C bond is faster than collapse of the intermediates to dibromides, this process will lead to fra j-stilbene (Scheme 9). We used this test to check the possibility of return in the bromination of unsubstimted, 4-methyl, 4-trifluoromethyl-, and 4,4 -bis(trifluoromethyl)-stilbenes in DCE (ref. 24). All these olefins gave clean third-order rate constants spanning 7 powers of 10. For each cis-trans couple the cis olefin was brominated 3.5 to 5.5 times faster than the trans isomer. Reactions for products analysis were performed at initial molar ratios of Br2 to olefin of 1 to 2, so that products arose only from the cis olefin, the trans isomer being accumulated in the reaction medium. 

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