Water permeable porosities and thermal conductivity of ceramic construction materials have been experimentally determined in this work. The samples were selected so as to obtain a wide variation in their apparent porosity. To study the influence of porosity on thermal conductivity, thermal conductivities of all the samples were measured in oven dried and water saturated conditions. A model relating porosity with thermal conductivity of these materials is proposed. In the model, two types of pores are hypothesized, namely; enclosed pores and enclosing pores. The three-dimensional steady-state heat transfer through unit cells containing each of the two types of pores, is solved to evaluate their effective thermal conductivity. By using the law of mixture for the random distribution of the type of pores, an equation combining the conductivities of the two cells is framed to get overall effective thermal conductivity of the material, in both dry and saturated states. The experimentally determined values of thermal conductivities reported in literature for some bricks are then compared with those predicted through this model.

Permeable Porosity and Thermal Conductivity of Construction Materials

Closed-form solutions of the in-plane effective thermal conductivities of woven-fabric composites

Describes class of spherically symmetric, high degree of freedom robots called "platonic beasts". A robot in this family is kinematically equivalent to a symmetric polyhedron, such as one of the platonic solids, with identical multi-purpose limbs attached to its vertices. The symmetry and regularity of the design have several advantages including robustness to toppling, novel gaits such as the rolling gait, and fault tolerance. The authors describe the design, simulation, and construction of a prototype platonic beast robot that the authors have built in their lab. The robot has four limbs, each with three degrees of freedom, and is controlled by a network of four embedded 32-bit microcontrollers. The authors also discuss the general features of these robots, including locomotion using the rolling gait and the implications of its novel features. >

Platonic beasts: a new family of multilimbed robots

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/24893/0000320.pdf?sequence=1

Vijay R. Raghavan

Papers

A thermal conductivity model for two phase media

Parametric analysis of direct contact sensible heat transfer in spray columns