In this study, the drying kinetics of saffron stigmas pretreated by atmospheric pressure cold plasma pretreatment (15, 30, 45 and 60 s) followed by hot air drying (60°C and 1.5 m/s) were modeled using 10 conventional mathematical thin layer models. The use of cold plasma pretreatment reduced drying time and enhanced effective moisture diffusivity (Deff). The most accurate models describing beha...

Thin-layer moisture adsorption tests were conducted by exposing com kernels to different air relative humidities (RH of 75, 80, and 90%) and temperatures (25, 30, 35, and 40°C). A two-dimensional finite element model was developed to simulate moisture diffusion into a com kernel during adsorption. The finite element model satisfactorily predicted experimental moisture ratio of corn samples and ...

The determination of the moisture diffusivity in capillary range is studied for rammed earth building materials, using X-ray method. To prevent liquefaction and expansion these materials during absorption test, a brick wick paper are added as lower sample parts confining sealing utilised. Since bring about composite case, compatibility with Boltzmann transformation must be redeveloped. It found...

The advection of a passive scalar by a quenched (frozen) incompressible velocity field is studied by extensive high precision numerical simulation and various approximation schemes. We show that second-order self-consistent perturbation theory, in the absence of helicity, perfectly predicts the effective diffusivity of a tracer particle in such a field. In the presence of helicity in the flow, ...

The advection-diffusion equation for the concentration of a tracer may be transformed into a pure diffusion equation by using the area inside concentration contours as a coordinate. The corresponding effective diffusivity depends on the geometry of the tracer field, which is determined by the underlying flow. Recent studies have used effective diffusivity, calculated from a suitable tracer, as ...

The produced liquid water in cathode catalyst layer (CCL) has significant effect on the operation of proton exchange membrane fuel cell (PEMFC). To investigate this effect, the transport of oxygen in CCL in the presence of immiscible liquid water is studied applying a two-dimensional pore scale model. The CCL was reconstructed as an agglomerated system. To explore the wettability effects, diffe...