Thermal Conductivity of Fresh Lamb Meat, Offals and Fat in the Range ‐40 to +30oC: Measurements and Correlations
ABSTRACT The thermal conductivity of fresh lamb meat, offals and fat was measured over the temperature range -40°C to +30°C using a guarded hot plate apparatus. Simple empirical equations were presented for the conductivity of high-moisture (65 to 80%) meat and offals. With independently obtained values of physical parameters, several theoretical models were tested to sec if thermal conductivity could be calculated from composition and temperature. Over a wide range of compositions and temperatures, best predictions (in terms of mean, standard deviation and range of errors) were obtained with Levy's modification to the Maxwell-Eucken equation. Its accuracy was not unduly sensitive to the uncertainties in the values of the physical parameters, the prediction errors remaining in the range ± 10% for all reasonable values of the latter.
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- "Fig. 3 shows that, since k water /k solids is relatively low, the choice of effective thermal conductivity model is not critical for Class I foods. Pham and Willix (1989) performed measurements on the effective thermal conductivity of meat, fat and offal between À40 °C and +30 °C, and compared the results to the predictions of six of the effective thermal conductivity models plotted in Fig. 1. They found that for the unfrozen materials (Class I foods) any of the six models provided satisfactory predictions, consistent with the previous discussion. "
ABSTRACT: In this study, it was shown that effective thermal conductivity models that are functions only of the components’ thermal conductivities and volume fractions could not be accurate for both granular-type porous foods (“external porosity”) and foam-type porous foods (“internal porosity”). An extra parameter is needed to make the model sufficiently flexible to allow it to be applied to porous foods with a range of different structures. A number of effective thermal conductivity models contain the required extra parameter, and of these, Krischer’s model appears to have received the greatest use in the food engineering literature; however, for isotropic materials it is recommended that a modified Maxwell model be used instead, because it assumes an isotropic physical structure, unlike Krischer’s model, and because the numerical value of the extra parameter may be estimated based on whether the food has internal or external porosity. A new procedure for predicting the effective thermal conductivity of non-frozen porous foods is presented as a flowchart.Journal of Food Engineering 08/2006; 75(3-75):297-307. DOI:10.1016/j.jfoodeng.2005.04.021 · 2.58 Impact Factor
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- "The model considers the Protein, Fat and Ash content, as a function of the thermal conductivity. Spells  model was considered by Pham  to obtain the conductivity of various kinds of meat. Comini et al. and Spells models deemed only the moisture content as the main parameter, which influenced the thermal conductivity. "
ABSTRACT: Thermal conductivity and thermal diffusivity of 'Hashi' camel meat were measured and predicted over a temperature range from 5-45°C. Thermal conductivity and thermal diffusivity were determined using a line heat source probe. The obtained values for thermal conduc vity varied from 0.482 to 0.494 W/m.°C and the percent standard errors varied from 3.2 to 5.2%. The thermal diffusivity values varied from 1.26 x 10-7 to 1.29 x 10-7 m2/s and the percent standard errors varied from 8.7 to 12.3%. Experimental values of the 'Hashi' camel meat were compared with the thermal conductivities and thermal diffusivities calculated using different empirical models.Journal of King Saud University - Science 01/2004; 16(2):153-160.
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ABSTRACT: In this paper influence of the water bolus temperature on the thermal distribution inside an homogeneous muscles phantom are analyzed for a microwave applicator for superficial hyperthermia on small subcutaneous tumors. Temperature simulations were used for the analysis considering two models with different thermal interfaces between the water bolus and the phantom. The results show dependence of the temperature peak deepness which position reduces increasing the bolus temperature with differences between the two models considered. These results can be used for a preliminary guideline for the choice of water bolus temperature to be used on hyperthermia treatment according to the tumor size and deepness.