In this research, the effect of PEO procedure time on the distinct properties of coatings such as morphology, chemical composition, roughness and corrosion has been studied. A scanning electron microscopy equipped with an energy dispersive spectroscopy was used to study the microstructure of the coatings. In addition, x-ray diffraction (XRD) and roughness meter were used to evaluate the chemica...

Measurements of the microwave power required for breakdown have been made in a simulated reentry boundary layer flow. By establishing a fully developed laminar pipe flow between cold walls, fed by a subsonic arc jet, we have simulated the appropriate boundary layer temperature, density, electron concentration, and chemical composition profiles over an altitude range from 80 to 180 kft. Correlat...

An analytic solution is presented describing ̄ow to a drain in a semi-in®nite domain bounded by a leaky layer of constant thickness. The solution is developed by applying the method of images to two parallel boundaries: an inhomogeneity boundary and an equipotential boundary. It is then demonstrated that the solution for the problem with the leaky layer approximated by a leaky boundary (a mixed...

By definition, web-services composition works on developing merely optimum coordination among a number of available web-services to provide a new composed web-service intended to satisfy some users requirements for which a single web service is not (good) enough. In this article, the formulation of the automatic web-services composition is proposed as several set-cover problems and an approxima...

[1] Tropospheric hydroxyl (OH) is the cleaning agent of the atmosphere, because most oxidation processes are initiated by OH. If the OH chemical system were unstable, runaway growth of oxidants (autocatalytic conditions) or of reduced gases (catastrophic conditions) might occur, especially because the atmospheric composition is changing rapidly. We present simulations with a global chemistry-tr...

The effects of chemical composition and preparation conditions, especially calcination atmosphere, water content and oxygen content on the catalytic performances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid have been investigated and discussed. Among the catalysts studied, the Mo1.0V0.3Te0.23Nb0.12O catalyst calcined in inert atmosphere under a ...

over the coming decades, global change will have an impact on food and water security and there are strong indications that developing countries will bear the brunt of adverse consequences from climate change. agricultural sector is the most vulnerable to climate change, because of its dependence on water and temperature conditions. consequently, it is important to understand the impacts of cli...