Effect of temperature on capacity

Fig. 5 Effect of temperature on capacity utilization of D size alkaline cells (3.9 ohm load). (From Ref. " l)...

FIGURE 11.15 Effect of temperature on capacity of a cadmium/mercuric oxide button battery (3000-mAh size). 

FIGURE 23.31 Effect of temperature on capacity of traction batteries, typical flat-plate design. From Ref. 23.)... 

FIGURE 24.9 Effect of temperature on capacity for D and X size cylindrical units. 

FIGURE 25.16 Effect of temperature on capacity and energy of nickel-iron battery (C/3 rate). 

Figure 30.32 Eagle Richer renwtely activated primary silver-zinc battery effect of temperature on capacity at constant discharge (Courtesy of Eagie Rchei)...

Figure 51.18 Effect of temperature on capacity of Eveready BH1 and BH1T sealed nickel-cadmiumbutton cells, 1.2V, 1 Ah capacity, discharge current 100 mA (Courtesyof Union Carbide)...

Figure 32.1 Effect of temperature on capacity of Eagie Rcher manuaiiy operated siiver-zinc ceiis (Courtesy of Eagie Richer)...

Temperature is of particular importance to the performance of anodes, especially when anodes are buried. Anodes may often be used to protect pipelines containing hot products. Thus temperature effects must be considered. Figure 10.14 illustrates the effect of temperature on different anodes in hot saline mud. Al-Zn-In anodes experience greatly reduced capacity in open seawater at temperatures above 70°C (down to 1200Ah/kg at 100°C) and in seabed muds in excess of (900 Ah/kg at 80°C). At... 

The effect of temperature on column efficiency, however, is frequently exploited, particularly in size exclusion chromatography (SEC). As has already been discussed, high efficiencies are essential in SEC due to the limited peak capacity of the column and consequently, the very small separation ratios. However the effect of temperature on column efficiency is not well understood by many analysts and consequently, will be discussed in some detail. It was shown on page... 

Fig. 3.10 The effect of temperature on the air-entraining capacity of sodium dodecyl sulfate in a cement paste (Bruere).

Figure 1. Effect of temperature on ammonia uptake capacity of 6.5 wt.% V20g/Ti02(A)...

Table 3.1 Effect of temperature on the capacity of D-size Leclanche and ZnCl2 cells when discharged continuously through 2.25 2 to a cut-off voltage of 0.9 V...

Figure 10 The Effect of pH on the CD Spectra (a) and the Effect of Temperature on the Heat Capacity (b) of Coiled Coils,63labc...

Figure 18.13 Effect of temperature on (a) apparent relative molar enthalpies (b) apparent molar volumes and (c) apparent molar heat capacities, for n-dodecylpyridinium chloride. The temperatures are (1) 298.15 K (2) 313.15 K and (3) 328.15 K.

Whereas the cooling capacity depends linearly on temperature, the heat production rate depends exponentially following the Arrhenius law. This may result in extremely high temperature maxima, if the control is not appropriate. Thus, it is important to characterize the effect of temperature on the heat balance. 

In Chapter 4 the effects of temperature on Af G ° and AfH ° and on ArG ° and ArH ° are discussed on the basis of the assumption that A,H° at zero ionic strength is independent of temperature. Therefore the effects of heat capacities of species were not treated. When a biochemical reactant contains two or more species, the standard transformed molar heat capacity of the pseudoisomer group is given by (Alberty, 1983a)... 

The effect of temperature on retention has been described experimentally,(4-8) but the functional dependence of k with temperature has only recently been described.W A thermodynamic model was outlined relating retention as a function of temperature at constant pressure to the volume expansivity of the fluid, the enthalpy of solute transfer between the mobile phase and the stationary phase and the change in the heat capacity of the fluid as a function of temperature.(9) The solubility of a solid solute in a supercritical fluid has been discussed by Gitterman and Procaccia (10) over a large range of pressures. The combination of solute solubility in a fluid with the equation for retention as a function of pressure derived by Van Wasen and Schneider allows one to examine the effect of solubility on solute retention. 

Adsorption is normally exothermic thus a decrease in temperature will increase the extent of adsorption whereas an increase in temperature will increase the adsorption capacity for chemisorption (normally endothermic). The heat of adsorption, AHads, is defined as the total amount of heat evolved per a specific amount of adsorbate adsorbed on an adsorbent. Because adsorption from an aqueous solution occurs, AHads is small, and thus small changes in temperature do not alter the adsorption process much. The effect of temperature on adsorption can be expressed by ... 

The effects of temperature on C or Cy are determined by experiment, most often from spectroscopic data and knowledge of molecular structure by the methods of statistical mechanics. Where experimental data are not available, methods of estimation are employed, as described by Reid, Prausnitz, and Sherwood.t Ideal-gas heat capacities increase smoothly with increasing temperature toward an upper limit, which is reached when all translational, rotational, and vibrational modes of molecular motion are fully excited. 

Figure 3 shows the effect of temperature on the capacity factor of p-nltroanillne, from 0°C to 77°C. A mobile phase consisting of 10 methanol/water was employed. The retention at 0°C was 23.62 min. while at 77°C was 2.28, a ten fold decrease. This decrease in retention may be attributed to many factors such as increased solubility of the p-nitroaniline with increase in temperature, which results in less solute-stationary phase, and an increase in solute-mobile phase Interactions increase in mass transfer, and decrease in the pressure. Also the binding constant of any solute with cyclodextrin goes to zero at 80°C (11). 

Figure 1. Effect of temperature on the capacity factor of naphthalene (—o—) and biphenyl (-0-) using a 6 cyclodextrin column, ii.6 x 100 mm, and a mobile phase of methanol/water at a flow rate of 1 ml/min.

The effects of temperature on the equilibrium capacity of active carbon for adsorption of 2,4-D and DNOSBP have been studied. The data are plotted in Figure 11, and the experimentally determined heats of adsorption are listed in Table IV. The values for AH for the 2,4-D and DNOSBP are remarkably similar, and as one would anticipate from considering the thermodynamics of adsorption, both values are negative. In view of the general range of the values for AH it may be anticipated that normal temperature variations in practical applications will not significantly affect ultimate capacity for sorption of organic pesticides on carbon. 

This heat must be dissipated by cooling, which can be done but only to a limited extent The ability to dissipate heat efficiently is usually the factor that limits the speed of electrophoresis, since excess heat leads to non-uniform electrophoresis and a decrease in resolution. The main reason for this is convection in matrix-free electrophoresis in solution, and the effect of temperature on viscosity and diffusion. High temperatures can also lead to denaturation of proteins and nucleic acids. The thinner the layer used for electrophoresis, the more readily is the heat dissipated, and the higher the voltages that can be used. The thickness of the layer will be a compromise between a desire to have a thin layer to minimise heat problems whilst maintaining sufficient capacity to ran samples that can be detected easily. Consis-... 

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