Sharif Digital Repository

The objective of this paper is to derive the mathematical model of two-dimensional heat conduction at the inner and outer surfaces of a hollow cylinder which are subjected to a time-dependent periodic boundary condition. The substance is assumed to be homogenous and isotropic with time-independent thermal properties. Duhamel's theorem is used to solve the problem for the periodic boundary condition which is decomposed by Fourier series. In this paper, the effects of the temperature oscillation frequency on the boundaries, the variation of the hollow cylinder thickness, the length of the cylinder, the thermophysical properties at ambient conditions, and the cylinder involved in some... 

Escherichia coli is widely used host for the intracellular expression of many proteins. However, in some cases also secretion of protein from periplasm was observed. Improvement of both intracellular and extracellular production of recombinant protein in E. coli is an attractive goal in order to reduce production cost and increase process efficiency and economics. Since heat shock proteins in E. coli were reported to be helpful for protein refolding and hindering aggregation, in this work different types of single and periodic heat shocks were tested on lab scale to enhance intracellular and extracellular protein production. A single heat shock prior to induction and different oscillatory...