The effect of catalyst particle size on dehydration of methanol to dimethyl ether is investigated using fixed bed and micro-channel reactors at different temperatures and weight hourly space velocities. The experiments were carried out at 290 and 320oC. The space velocities were changed from 10 up to 90h-1 and from 1.22 to 3.65h-1 for fixed bed and micro-channel reactors, respectively. Consider...

Several researches dealing with the single-phase forced convection heat transfer inside micro channels have been published in the past decades. The performance of liquid flow has been proved that agree with the conventional correlations very well (Yang and Lin [2007]). However, owing to the low heat transfer coefficient of gaseous flow, it is more difficult to eliminate the effects of thermal s...

The properties of double-stranded DNA and other chiral molecules depend on the local geometry, i.e., on curvature and torsion, yet the paths of closed chain molecules are globally restricted by topology. When both of these characteristics are to be incorporated in the description of circular chain molecules, e.g., plasmids, it is shown to have implications for the total positive curvature integ...

Final quality of products/services starts with suppliers in the supply chain. Problems can occur if suppliers do not deliver the quantities requested in full, on time, or buyers select suppliers solely on the basis of lowest price. Supplier selection has been studied for large businesses but not for very small (micro) businesses. Therefore, a survey was administered to micro-businesses to deter...

Micro-expression is gaining more attention in both the scientific field and the mass media. It represents genuine emotions that people try to conceal, thus making it a promising cue for lie detection. Since micro-expressions are considered almost imperceptible to naked eyes, researchers have sought to automatically detect and recognize these fleeting facial expressions to help people make use o...

In this paper, we derive a capacity inner bound for a synchronous Gaussian Z channel with intersymbol interference (ISI) under input power constraints. This is done by converting the original channel model into an n-block memoryless circular Gaussian Z channel (n-CGZC) and successively decomposing the n-block memoryless channel into a series of independent parallel channels in the frequency dom...

gas mixing in a t-shape micro mixer has been simulated using the direct simulation monte carlo (dsmc) method. it is considered that the adequate mixing occurs when the mass composition of the species, co or n2, deviates below 1 % from their equilibrium composition. the mixing coefficient is defined as the ratio of the mixing length to the main channel’s height. as the inlet kn increases, while ...

Because the electrical installations are nowadays a lot of options and variants, it is necessary to evaluate these complex installation process from several perspectives and objectively. Due to the complexity of evaluation of electrical installation is design a methodology that uses multi-criteria analysis MCA.