Search Results
): 1267 – 1277 . Karawacki , E. , Suleiman , B. M. , Ul-Hang , I. , Nhi , B. T. ( 1992 ). An extension to the dynamic plane source technique for measuring thermal conductivity
, and the obtained data were analysed by statistical method (analysis of variance). 2 Theoretical background Thermal effusivity e depends on the thermal conductivity κ , density ρ , and the volume
Samples of surimi were prepared under laboratory conditions from Adriatic pilchard ( Sardina pilchardus). Water content in surimi was 81.5% before mixing with NaCl and &-carrageenan, which were added in the range of mass fraction from 0 to 10%. Relative apparent specific enthalpy ( H -), initial freezing point T i, density p and thermal conductivity k of surimi in the temperature range from -25 °C to 10 °C were determined by differential thermal analysis (DTA), gravimetric method and line-heat source technique, respectively. For determination of relative apparent specific enthalpy ( H -) the mathematical model of enthalpy based on orthogonal collocation approximation of DTA was applied. Redistributions of apparent enthalpy in the freezing range as functions of mass fractions of added substances were determined. Increase of mass fraction of added substances resulted in the increase of mass fraction of bound (unfreezable) water and lowered initial freezing point T i, which has effects on the decrease of thermal conductivity k and increase of apparent specific enthalpy ( H -) in the temperature range from -25 °C to T i . This effect was more pronounced for samples where surimi was mixed with NaCl.
Abu-Hamdeh, N.H. 2000. Effect of tillage treatments on soil thermal conductivity for some Jordanian clay loam and loam soils. Soil and Tillage Res. 56 :145–151. Abu
. Usowicz , B. , Lipiec , J. & Usowicz , J. B. 2008 . Thermal conductivity in relation to porosity and hardness to terrestrial porous media . Planet. Space Sci. , 56 . 438 – 447
= freezing temperature (°C) (calculated by needle-based thermocouple) T a = freezing temperature of medium (°C) h = convective heat transfer coefficient at the surface of the food (h =7.26 W m -2 k -1 ) k f = thermal conductivity of the frozen food (k =1
42 1448 1453 Usowicz, B., Lipiec, J. & Usowicz, J. B. , 2008. Thermal conductivity in relation to porosity and hardness to terrestrial
