Capacity temperature influence

The press temperature influences the possible press time and therefore the capacity of the production line. The minimal press time has to guarantee that the bond strength of the still hot board can withstand the internal steam pressure as well as the elastic spring back of the board when the press opens or when the board leaves the continuous press. 

The small heat capacity of silica CEC columns means that column temperature is easily changed. Temperature influences EOF velocity through its effect on zeta potential and mobile-phase viscosity [Eq. (4)]. Increased temperature reduces r via an exponential relation ... 

Drying capacity is influenced by the speed of the drum and the temperature of the feed, which may be preheated. With the double-drum drier, the gap between the cylinders determines the thickness of the film. 

The influence of physical water parameters such as pH or temperature on the performance of the adsorption process is quite small in the range relevant for drinking water production. Activated carbon (F-400) shows a slight decline in capacity with raising temperature whereas on Ambersorb 572 no effect was observed [28]. In column tests, the temperature influence observed was only small [59]. 

Soil factors which influence both manganese deficiency and toxicity include pH value, the concentration of Mn + and other cations, cation exchange capacity, temperature, organic matter content, microbial activity, and redox potential. A unit reduction in pH increases the Mn " concentration about 100-fold thus, the pH value of the soil is the decisive factor related to deficiency and toxicity (Bergmann 1992). 

Tables 21 and 22 summarize the usual press strategies for the production of particleboards and MDF. The warming up of the mat is performed by the so-called steam shock effect [442-447]. The precondition for this is the high permeability to steam and gases of the particle or fiber mat [442,443,448,449]. High moisture contents of the face layers and spraying of water on the surface layers sustain this effect. The press temperature influences the possible press time and by this the capacity of the production line. The minimum press time has to guarantee that the bond strength of the still hot board can withstand the internal steam pressure as well as the elastic springback in board thickness at press opening.

The usual way of analyzing the temperature influence is to assume that the side reactions rates follow an Arrhenius law, i.e. increase exponentially with temperature, through a coefficient linked to an "activation energy," E k = ko-e, or log(k) = In(ko) - E/RT. The difficulty comes from the fact that a global phenomenon (for example, capacity loss, or impedance increase) may result from several reactions, each with their own activation energy and rate constant Furthermore, the rate of the phenomena observed are often assumed to be constant with time, which can lead to hazardous... 

Any variable or parameter that influences kinetics can be used if well-defined perturbation can be achieved. Temperature was the early favorite in kinetic studies, but in catalysis the heat capacity of the catalyst makes the response for temperature changes very sluggish. A sudden change in one or more of the product or reactant concentrations can be executed faster and usually gives a better response signal. 

Adsorption for gas purification comes under the category of dynamic adsorption. Where a high separation efficiency is required, the adsorption would be stopped when the breakthrough point is reached. The relationship between adsorbate concentration in the gas stream and the solid may be determined experimentally and plotted in the form of isotherms. These are usually determined under static equilibrium conditions but dynamic adsorption conditions operating in gas purification bear little relationship to these results. Isotherms indicate the affinity of the adsorbent for the adsorbate but do not relate the contact time or the amount of adsorbent required to reduce the adsorbate from one concentration to another. Factors which influence the service time of an adsorbent bed include the grain size of the adsorbent depth of adsorbent bed gas velocity temperature of gas and adsorbent pressure of the gas stream concentration of the adsorbates concentration of other gas constituents which may be adsorbed at the same time moisture content of the gas and adsorbent concentration of substances which may polymerize or react with the adsorbent adsorptive capacity of the adsorbent for the adsorbate over the concentration range applicable over the filter or carbon bed efficiency of adsorbate removal required. 

The sensor is the element of an instrument directly influenced by the measured quantity. In temperature measurement the thermal mass (capacity) of the sensor usually determines the meter s dynamics. The same applies to thermal anemometers. In IR analyzers used for concentration measurement, the volume of the flow cell and the sample flow rate are the critical factors. Some instruments, like sound-level meters, respond very fast, and follow the pressure changes up to several kHz. 

The influence of the presence of sulfur adatoms on the adsorption and decomposition of methanol and other alcohols on metal surfaces is in general twofold. It involves reduction of the adsorption rate and the adsorptive capacity of the surface as well as significant modification of the decomposition reaction path. For example, on Ni(100) methanol is adsorbed dissociatively at temperatures as low as -100K and decomposes to CO and hydrogen at temperatures higher than 300 K. As shown in Fig. 2.38 preadsorption of sulfur on Ni(100) inhibits the complete decomposition of adsorbed methanol and favors the production of HCHO in a narrow range of sulfur coverage (between 0.2 and 0.5). 

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