AbstractsGeography &GIS

"The problem to be investigated in this thesis is that of periodic heat flow in a semi-infinite solid. Periodic flow means that heat flow is a continuous function of time and repeats itself at regular intervals. A semi-infinite solid is one which is bounded by one and only one plane. This subject has received considerable attention in the field of soil temperatures, both at the surface of the earth and at various depths. The surface of the earth is subjected to temperature changes which are nearly periodic. These temperature changes take place both daily and annually. A knowledge of these fluctuations is helpful in deciding such things as the depth at which water main will be out of danger of freezing. Its importance is not limited to problems on the earth's soil. The subject has also received attention in the fields of heat flow in cylinder walls. It is of interest in the field of temperature stresses where these stresses are set up by expansions and contractions of the material subjected to cyclic temperatures. Because the analytical treatment becomes very involved in the more complex problems, these problems are usually attacked from the physical measurement standpoint. This particular subject was chosen by the author because thus far all analytical treatment has been on the basis of heat flow taking place by conduction alone. It is the object of this paper to investigate the feasibility of considering the effect of both convection and conduction on the flow of heat" – Introduction, p. 1-2.