Search

The paper examines the possibility of hydraulic characterization of radial well laterals in a manner that does not require prior hydrodynamic analysis by simulating groundwater extraction conditions on a numerical model. The first step of the proposed approach is to assess the groundwater level regime formed in the capture zone when the well is operating, which is indicative of the functional condition of the laterals and the aquifer potential in terms of groundwater availability. Then the efficiency of the laterals is examined through the hydraulic function of the skin zone, depending on its filtration properties. An expression for groundwater flow from the aquifer to the laterals (commonly used to simulate laterals on a hydrodynamic model) is employed to define representative values of the conductance coefficient of the skin zone (as an indicator of colmation), and then applied to several wells at Belgrade Groundwater Source. The present research shows that a conductance coefficient of [Ks/ds]=1.0×10-4 s-1 can be considered as the threshold value in relation to which the effects of colmation of well laterals are exhibited, which is consistent with the results reported by researchers who studied the effect of skin zone conductance on the occurrence and nature of the so-called early drawdown at radial collector wells. In addition to gaining insight into the present condition of the laterals, the proposed approach can be used to study the progress of colmation at different points in time and to quantify the effectiveness of regeneration of laterals. [Projekat Ministarstva nauke Republike Srbije, br. OI176022, br. TR33039 i br. III43004]

Gate insulator (GI) materials in top gate structured InGaZnO thin-film transistor (TFT) with copper gate electrode are examined for the application to the large area display. To overcome the problems with hydrogen diffusion, which can influence the number of carriers in oxide semiconductor and to gain large trans-conductance coefficient, a double-layered GI of 30 nm Al2O3/120 nm SiN xis adopted. The TFT showed field-effect mobility, Von, SS, and hysteresis of 12.8 cm2 V−1 s−1, −0.7 V, 0.17 V decade−1, and almost 0 V, respectively, and the ΔVon under the positive bias stress of 20 V and negative bias stress of −20 V at 60 C for 10 000 s are +0.1 and −0.4 V, respectively. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we propose a local and contextual controlled (LCC) fourth order PDE method for noise removal. In our method, two discontinuity measures are incorporated into a LCC fourth order PDE, where the joint use of the two discontinuity measures leads to a complementary effect for edge preservation. Moreover, the proposed method inherits the advantage of fourth order PDE which is able to avoid the blocky effects widely seen in images processed by second order PDE. Compared with existing four order PDEs, our proposed method can remove isolated speckles and keep the edges from being blurred. The numerical experiments show that the proposed method can outperform the pre-existing methods in terms of the quality of the processed image. [Copyright &y& Elsevier]