Thermal conductivity Effect

Carne, M., and D. H. Charlesworth, 1966, Thermal Conduction Effects on the Critical Heat Flux in Pool Boiling, Chem. Eng. Prog. Symp. Ser. 62(64) 24-34. (5)... 

The physical properties of the catalyst (specific surface area, porosity, effective thermal conductivity, effective diffusivity, pellet density, etc.). 

A schematic plot of thermophoretic velocity (Eq. 11.21) as a function of particle diameter for air at normal temperature and pressure is shown in Fig. 11.4. It can be seen that the thermophoretic velocity decreases from a high value at small particle sizes to a somewhat lower constant value for large particle sizes. The range of the region of changing vT is approximately 0.01 < d p,m < 40, and the thermal conductivity effect of a particle begins to become apparent above about d 0.2 p,m. 

Kottke, T., and Niiler, A., Thermal Conductivity Effects on SHS reactions, USA Ballistic Research Laboratory. Aberdeen Proving Ground, MD (1988). 

Another study by Wu et al. [72] focused on the development of the PLA nanocomposites with various functionalized MWCNTs prepared by melt mixing for morphological, rheological and thermal measurements. The surface functionalization influences the dispersion state of MWCNTs in the PLA matrix strongly as the carboxylic functionalized MWCNTs show relatively better dispersion than that of hydroxy and purified MWCNTs, which is due to the nice affinity between carboxylic group and PLA. For all composites, no remarkable improvement in thermal stability is seen at the initial stage of degradation, while with increase of decomposition level, the presence of carboxylic and purified MWCNTs retards the thermal depolymerization of PLA due to their barrier and thermal conductive effects, respectively. 

The process is controlled by many operating parameters, such as (1) intrinsic parameters like shape and size of the raw material, initial water content, specific heat, thermal conductivity, effective diffusivity, etc. (2) operating process parameters like P, T, f, P, T, and T (3) kinetic parameters like pressure drop rate (APa/At) = (P - P )IAt and temperature... 

Mass spectrometer [1], thermal conductivity [2, 3] and catalytic conversion methods [4, 5] have been used to determine trace impurities in helium. These methods are, however, inadequate for the present purpose for various reasons. The mass spectrometer, such as Consolidated Electrodynamics Corporation 21-103, is limited in sensitivity, for most contaminants, to out 25 ppm. Instruments based on the thermal conductivity method, such as those manufactured by Cow-Mac Instrument Co., Beckman Instruments and others, are satisfactory for monitoring nitrogen and hydrogen in helium, but since these gases have opposite thermal conductivity effects, this method, when used alone, gives indefinite results. Catalytic conversion methods, such as are employed in an instrument manufactured by Baker and Company for analysis of trace quantities of hydrogen and oxygen, are not responsive to other impurities and are therefore poorly adapted to an overall analysis of trace impurities in helium. 

The microwave absorption is converted as heat generation in the material. As mentioned before, two main mechanisms describe the microwave absorption dipole orientation and resistive heating. Depending on the nature of the susceptor, the heating can be traced back to one specific mechanism or the combination of several of them [30]. The microwave radiation strongly increases the temperature of the additives. The polymeric material is also heated though a thermally conductive effect. Dispersion of the additives, interphase, concentration and the nature of the susceptor, are critical parameters for the heating efficiency of the composite material. 

N. H. Abu-Hamdeh and R. C. Reeder. Soil thermal conductivity effects of density, moisture, salt concentration, and organic mattter. Soil Science Society of America Journal, 64 (2000), 1285-1290. 

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