this article addresses the interplay between heat of hydration and physico-mechanical properties of calcium sulfate hemi-hydrate in the presence of retarding additives such as citric and malic acids and sodium citrate. the heat of hydration was measured using a semi-isothermal calorimeter. results proved that citric and malic acids had superior impact on hydration and mechanical properties. whi...

in this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (gdl) of pem fuel cell is modeled. the governing equations including energy, mass and momentum conservation equations are solved by numerical methods. also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (gdl) thickness and inlet relative humidity are calculated...

The mixing behavior of the gas-liquid phase in three loop bioreactors was investigated. A gas-induced External Airlift Loop Bioreactor (EALB), a forced-liquid Vertical Tubular Loop Bioreactor (VTLB) and a forced-liquid Horizontal Tubular Loop Bioreactor (HTLB) were used for mixing studies as well as biomass production from natural gas. The effect of design parameters, riser to downcomer cro...

For a general group G we consider various weak mixing properties of nonsingular actions. In the case where the action is actually measure preserving all these properties coincide, and our purpose here is to check which implications persist in the nonsingular case.

A binary relation R on a set S is transitive iff for all a, b, c ∈ S, if aRb and bRc, then aRc. This almost never applies to the relations logicians tend to think of as consequence relations; where such relations are relations on a set at all, they are rarely transitive. Yet it is common to hear consequence relations described as ‘transitive’, and to see rules imposed to ensure ‘transitivity’ o...

I recount briefly the history of neutrino tribimaximal mixing and the use of the discrete family symmetry A4 in obtaining it. Talk at the 4th International Conference on Flavor Physics, Beijing, September 2007. 1 Neutrino Tribimaximal Mixing In 1978, soon after the putative discovery of the third family of leptons and quarks, it was conjectured by Cabibbo [1] and Wolfenstein [2] independently t...

In order to enhance the performance of interconnects which are used in solid oxide fuel cells (SOFCs), a protective/conductive coating can be applied. In this research AISI 430 ferritic stainless steel was coated in a Mn-base pack mixture by pack cementation method. In order to evaluate the oxidation behavior, isothermal oxidation was accomplished for 200 h at 800 ºC. Electrical behavior was al...

In order to rapidly predict the performance of hydrocarbon-fueled regeneratively cooled scramjet engine in system design, a quasi-one-dimensional model has been developed. The consists supersonic combustor with finite-rate chemistry and cooling channel real gas working medium, which are governed by two sets ordinary differential equations separately. Additional models for wall friction, heat tr...