روزنامه با شماره پیاپی سال 2003

11

225

235

Aqueous solutions of polymers such as Carbopol and carboxymethyl cellulose (CMC) solutions are employed in laboratory for simulation of the thermo-rheological behaviour of complex fluids. Then, it is necessary to know their thermophysical properties with good precision. Especially, study of the constant pressure specific heat allows to undertake thermal balance and to describe the temperature field evolution under unsteady conditions. Experimental results concerning the direct measure of the specific heat of two complex solutions in the range of temperatures (20–90 °C) are presented and detailed in this work. The temperature dependence of the specific heat is higher for CMC solutions than for Carbopol solutions. Furthermore, an energy contribution of molecular origin is put into evidence from the study of the concentration dependence of the specific heat. Thus, the excess in specific heat value can reach 8% of the water specific heat value.

Food Microbiology

2003

Food Microbiology