Image dehazing using morphological opening,dilation and Gaussian filtering

Image pre-processing is a critical stage in computer vision systems, with greater relevance when the input images are captured in outdoor environments because the pictures could contain low contrast and modified colors. A common condition present in outdoor images is haze. In this work, a new dehazing algorithm based on dark channel prior mathematical morphology operations (opening and dilation), and a Gaussian filter, is proposed. Moreover, the proposed algorithm performance is compared qualitatively and quantitatively against previously reported algorithms. Obtained results show that the proposed algorithm requires less processing time providing higher quality dehazing results than other state-of-the-art approaches.     

Cat-CVD-prepared oxygen-rich μc-Si:H for wide-bandgap material

Microcrystalline phase-involved oxygen-rich a-Si:H (hydrogenated amorphous silicon) films have been obtained using catalytic chemical vapor deposition (Cat-CVD) process. Pure SiH₄ (silane), H₂ (hydrogen), and O₂ (oxygen) gases were introduced in the chamber by maintaining a pressure of 0.1 Torr. A tungsten catalyzer was fixed at temperatures of 1750 and 1950 °C for film deposition on glass and crystalline silicon substrates at 200 °C. As revealed from X-ray diffraction spectra, the microcrystalline phase appears for oxygen-rich a-Si:H samples deposited at a catalyzer temperature of 1950 °C. However, this microcrystalline phase tends to disappear for further oxygen incorporation. The oxygen content in the deposited films was corroborated by FTIR analysis revealing SiOSi bonds and typical SiH bonding structures. The optical bandgap of the sample increases from 2.0 to 2.7 eV with oxygen gas flow and oxygen incorporation to the deposited films. In the present thin film deposition conditions, no strong tungsten filament degradation was observed after a number of sample preparations.     

Anisotropic membrane materials for gas separations

To date the design of membranes for gas separations has relied on isotropic materials that control the magnitude of mass flux. However, mass flux is a vector quantity and controlling its direction is essential for complete manipulation of diffusion processes. In this article, we show how anisotropic materials enable control of mass flux direction in membranes and allow for novel mechanisms for gas separation. We present a detailed study of the design parameters that control membrane selectivities and permeances and demonstrate that this new class of membranes can provide a new avenue to obtain significant improvements with respect to isotropic materials. We also discuss how the proposed anisotropic membranes can be constructed using isotropic materials. Mass diffusion principles for gas separations in anisotropic membranes are different from those in isotropic materials and this novel strategy for the design of membranes can open new opportunities in membrane separation processes.