Evaluation of ground water quality using multiple linear regression and structural equation modeling

A methodology for characterizing ground water quality of watersheds using hydrochemical data that mingle multiple linear regression and structural equation modeling is presented. The aim of this work is to analyze hydrochemical data in order to explore the compositional of phreatic aquifer groundwater samples and the origin of water mineralization, using mathematical method and modeling, in Maknassy Basin, central Tunisia). Principal component analysis is used to determine the sources of variation between parameters. These components show that the variations within the dataset are related to variation in sulfuric acid and bicarbonate, sodium and cloride, calcium and magnesium which are derived from water-rock interaction. Thus, an equation is explored for the sampled ground water. Using Amos software, the structural equation modeling allows, to test in simultaneous analysis the entire system of variables (sodium, magnesium, sulfat, bicarbonate, cloride, calcium), in order to determine the extent to which it is consistent with the data. For this purpose, it should investigate simultaneously the interactions between the different components of ground water and their relationship with total dissolved solids. The integrated result provides a method to characterize ground water quality using statistical analyses and modeling of hydrochemical data in Maknassy basin to explain the ground water chemistry origin

Kinematics effect on honeycomb sandwich beams vibration

Composite structures are used in aerospace, aeronautics, and automotive industries, especially composite sandwich panels which are exposed to vibration, noise, and unusual loads. They are often considered to support vibrations due to their important resistance to fatigue. The aim of this work is to study the influence of displacement fields on the vibration of honeycomb sandwich beams, considering two materials: Nomex paper and Aluminum alloy. For this purpose, the minimum energy method is used to derive the natural frequencies and modal shapes equations of a cantilever honeycomb sandwich beam. The kinetic and potential energies of skins are derived using the classical laminate theory, and several polynomial displacement fields are tested. The effect of core rotational inertia and bending energy on the sandwich beam vibration is also studied. The modal shapes are then examined. Besides, an experimental study is done on the cantilever honeycomb sandwich beam, using an impact hammer for excitation and a laser vibrometer for measurement. The natural frequencies are then obtained by modal analysis. In addition, a numerical simulation is conducted on the cantilever honeycomb sandwich beam to complete this work, and the natural frequencies obtained analytically, numerically, and experimentally are compared. Future steps to enhance this work are finally advanced

Piezometric levels as possible indicator of aquifer structure: analysis of the data from Maknassy basin aquifer system (Central Tunisia)

International audienc

Piezometric levels as possible indicator of aquifer structure: analysis of the data from Maknassy basin aquifer system (Central Tunisia)

International audienc

Groundwater resources in Maknassy basin (central Tunisia): hydrological data analysis and water budgeting

International audienc