In the present study, ultra-thin layer ZnS is inserted in the structure of standard solar cell between CdS buffer layer and CZTS absorber layer to represent the Second Phase (SP) often forms on the top of CZTS. The impact of this layer on the performance of CZTS solar cells is illustrated by the diverse results obtained by simulation using SCAPS-1D. The formation of ZnS on the CZTS surface has harmful effects on the solar cells parameters where the conversion efficiency (η) decreases by 2%. When varying thickness of ZnS SP of 2% to 20% corresponding of the total absorber layer the efficiency decreases by about 0.65%. The ZnS SP can deteriorate the photovoltaic power conversion efficiency from 10.2% to levels of 8.8%, depending on the material buffer layer and the thickness of ZnS SP. Using the ZnS as buffer layer mitigates harmful effects of the ZnS secondary phase forms on the top of CZTS absorber layer.

During the last decade, the construction sector in Algeria has been in constant development with higher demands for urban lands. This has resulted in placing building foundations in closer proximities with potential impact on the bearing capacity and settlements. Moreover, there have been limited investigations on the interference and overlapping effects on the ultimate bearing capacity of closely placed footings. This work explains the numerical investigation of the interference effect of juxtaposed strip footings based on a bilayer granular soil. A numerical model, based on the finite element method, was developed using Plaxis Package. The influence of spacing between foundations, friction angle, Young's modulus and thickness of the first layer on the efficiency factor ξγ were examined. The obtained results show clearly that the efficiency factor depends significantly on the thickness and strength of the first layer.

A numerical simulation is presented to study loose sand improved by stone column (SC) to reduce potential of liquefaction by the drainage effect by this column. The proposed simulation aims to design a unit cell which is consisted of a column and its surrounding soil; it is modeled in 3D under a gravity load and is subjected dynamically to a sinusoidal load. A Finn model is considered for the sand to analyze the evolution of the excess pore water pressure (EPWP), and the column is modeled by the Mohr–Coulomb yield criterion. Parametric studies are included geometrically the effect of the diameter of the stone column and dynamically the effect of dynamic criterions of Finn model and the frequency content of the dynamic load. The numerical simulation of the unit cell gives interesting results in the dynamic behavior of a loose sand reinforced by stone column, and it is suggested for designing the mitigation of liquefaction of loose sand improved under the effect of gravity.