Effect of Compression on Sensitiveness

Effect of Compression on Sensitiveness of Initiation, See Vol 3 of Encycl, p C492-L, under Compression, Effect on Sensitiveness of Initiation... 

A more detailed version of the Stranks approach would incorporate the notion due to Sutin [4, 5] that electron transfer within the precursor assemblage ML(f+i)+,ML + occurs over a reaction zone of thickness Sa rather than on hard-sphere contact of the reactants. In that case, a must be treated as pressure-sensitive, compressing along with the solvent. It turns out, however, that allowance for compression of a in Eqs (5.6) and (5.7) can be neglected for adiabatic reactions because it is almost exactly cancelled by a term AVp representing the effect of compression on the pre-exponential part of the expression for [9] (the exponential part generates AV j). Electron transfer, however, could be non-adiabatic -... 

The effect of compressed CO2 on the esterification of acetic acid and ethanol in [bmim][HS04]) at 60.0°C up to 15 MPa were studied (Figure 17). There was only one phase in the reaction system without CO2. However, CO2 can induce phase separation of the reaction system. As the pressure is less than 3.5 MPa, there are two phases in the system and increase in pressure can enhance the equilibrium conversion. In the pressure range of 3.5-9.5 MPa, there are three phases in the system and the equilibrium conversion increases rapidly with increasing pressure. The third phase disappears as the pressure is larger than 9.5 MPa, where the equilibrium conversion remains at high values and is not sensitive to pressure. 

The effect of compression speed on the yield pressure of a material has been suggested as a method of determining the time-dependent nature of materials compression properties (Roberts and Rowe 1985). Heckel plots are produced at two punch velocities, 0.03 and 300 mm sec, and the yield pressures determined. The strain rate sensitivity (SRS) is calculated as ... 

When considering the potential effect of pressure on a system, it is useful to recognize the magnitude of pressure required to significantly alter molecular and bulk properties. The isothermal compressibility, k (or its reciprocal K, the bulk modulus) (Eq. 2), gives an indication of the sensitivity of a system to pres-... 

The work on iron-nickel alloys has described shock-compression measurements of the compressibility of fee 28.5-at. % Ni Fe that show a well defined, pressure-induced, second-order ferromagnetic to paramagnetic transition. From these measurements, a complete description is obtained of the thermodynamic variables that change at the transition. The results provide a more complete description of the thermodynamic effects of the change in the magnetic interactions with pressure than has been previously available. The work demonstrates how shock compression can be used as an explicit, quantitative tool for the study of pressure sensitive magnetic interactions. 

Reavell(17) has given a comparison of costs for the concentration of a feed of a heat-sensitive protein liquor at 1.70 kg/s from 10 per cent to 50 per cent solids, on the basis of a 288 ks (160 hour) week. These data are shown in Table 14.3. It may be noted that, when using the double-effect evaporation with vapour compression, a lower temperature can be used in the first effect than when a triple-effect unit is used. In determining these figures no account has been taken of depreciation, although if this is 15 per cent of the capital costs it does not make a significant difference to the comparison. 

Dunkle s Syllabus (1957-1958) Shock Tube Studies in Detonation (pp 123-25) Determination of Pressure Effect (144-45) Geometrical and Mechanical Influences (145-48) Statistical Effects of Sensitivity Discussion on Impact Sensitivity Evaluation (148-49) Pressure in the Detonation Head (175) Temperature of Detonation (176) Charge Density, Porosity, and Granulation (Factors Affecting the Detonation Process) (212-16) Heats of Explosion and Detonation (243-46) Pressures of Detonation (262-63) A brief description of Trauzl Block Test, Sand Test, Plate Dent Test, Fragmentation Test, Hess Test (Lead Block Crushing Test), Kast Test (Copper Cylinder Compression Test), Quinan. Test and Hop-kinson Pressure Bar Test (264-67) Detonation Calorimeters (277-78) Measurements... 

The mechanical properties of Micelle-Templated Silicas (MTS) are very sensitive items for industrial process applications which might submit catalysts or adsorbents to relevant pressure levels, either in the shaping of the solid or in the working conditions of catalysis or separation vessels. First studies about compression of these highly porous materials have shown a very low stability against pressure. These results concern these specific materials tested. In this study, we show very stable MTS with only a loss of 25% of the pore volume at 3 kbar. The effects of several synthesis parameters on the mechanical strength are discussed. 

Ignition delays, investigated in adiabatic compression machines (89, 91, 92, 106, 182, 209, 212, 213), have been correlated with knock (90, 93-5, 111, 158, 160, 194, 203). Ignition occurs in two stages. Levedahl (106) examined the effects of temperature, density, and fuel type on the induction periods, ti and r2, corresponding to each ignition stage. A close correlation existed between total delay, r, and knock resistance. Sensitivity was explained in terms of the relative partial contributions of n and r2 to r. 

The most straightforward way to measure the effect of low temperatures on recovery is by means of a compression set or tension set test. Tests in compression are favoured and a method has been standardised internationally. The procedure is essentially the same as set measurements at normal or elevated temperatures and has been discussed in Chapter 10, Section 3.1. As the recovery of the rubber becomes more sluggish with reduction of temperature the dynamic loss tangent becomes larger and the resilience lower (see Chapter 9), and these parameters are sensitive measures of the effects of low temperatures. Procedures have not been standardized, but rebound resilience tests are inherently simple and quite commonly carried out as a function of temperature. It is found that resilience becomes a minimum when the rubber is in its most leathery state and rises again as the rubber becomes hard and brittle. 

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