Solid household waste characterization and fresh leachate treatment

Fatima Benyoucef,Abdelhadi Makan,Abderrahman El Ghmari,Aziz Ouatmane 대한환경공학회 2015 Environmental Engineering Research Vol.20 No.4

This study aims to characterize solid household waste and to present physicochemical characteristics of fresh leachate before landfilling in Kasba Tadla city, Morocco. Obtained results show that household waste produced in 2013 were about 11,787 tons, or 0.27 tons/capita/year. These wastes were composed essentially of organic materials (74%), paper (8%), plastics (9%), metals (1%), and glass (0.5%). However, monthly produced leachate ranges from a maximum of 130.92 ㎥ during summer and a minimum of 21.88 ㎥ in winter. Moreover, leachate treatment using Upflow Anaerobic Sludge Blanket technique was accompanied by a decrease in electrical conductivity, certainly related to leachate-sediment chemical exchanges. Otherwise, the same acidity reduction phenomenon occurs when pH value increased from 4.49 to 6.17 after 24 hours, confirming the system response since the early stages of treatment. In addition, temporal evolution of the treatment efficiency in terms of COD highlighted a very important reduction which reached 94% after 5 days with an average temperature of 25℃.

Robust quasi 3D computational model for mechanical response of FG thick sandwich plate

Samir Benyoucef,Fatima Achouri,Fouad Bourada,Rabbab Bachir Bouiadjra,Abdelouahed Tounsi 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.70 No.5

This paper aims to develop a quasi-3D shear deformation theory for the study of bending, buckling and free vibration responses of functionally graded (FG) sandwich thick plates. For that, in the present theory, both the components of normal deformation and shear strain are included. The displacement field of the proposed model contains undetermined integral terms and involves only four unknown functions with including stretching effect. Using Navier’s technique the solution of the problem is derived for simply supported sandwich plate. Numerical results have been reported, and compared with those available in the open literature were excellent agreement was observed. Finally, a detailed parametric study is presented to demonstrate the effect of the different parameters on the flexural responses, free vibration and buckling of a simply supported sandwich plates.

Improved analytical method for adhesive stresses in plated beam: Effect of shear deformation

Guenaneche, B.,Benyoucef, S.,Tounsi, A.,Adda Bedia, E.A. Techno-Press 2019 Advances in concrete construction Vol.7 No.3

This paper introduces a new efficient analytical method, based on shear deformations obtained with 2D elasticity theory approach, to perform an explicit closed-form solution for calculation the interfacial shear and normal stresses in plated RC beam. The materials of plate, necessary for the reinforcement of the beam, are in general made with fiber reinforced polymers (Carbon or Glass) or steel. The experimental tests showed that at the ends of the plate, high shear and normal stresses are developed, consequently a debonding phenomenon at this position produce a sudden failure of the soffit plate. The interfacial stresses play a significant role in understanding this premature debonding failure of such repaired structures. In order to efficiently model the calculation of the interfacial stresses we have integrated the effect of shear deformations using the equilibrium equations of the elasticity. The approach of this method includes stress-strain and strain-displacement relationships for the adhesive and adherends. The use of the stresses continuity conditions at interfaces between the adhesive and adherents, results pair of second-order and fourth-order coupled ordinary differential equations. The analytical solution for this coupled differential equations give new explicit closed-form solution including shear deformations effects. This new solution is indented for applications of all plated beam. Finally, numerical results obtained with this method are in agreement of the existing solutions and the experimental results.

Effect of porosity on vibrational characteristics of non-homogeneous plates using hyperbolic shear deformation theory

Mouaici, Fethi,Benyoucef, Samir,Atmane, Hassen Ait,Tounsi, Abdelouahed Techno-Press 2016 Wind and Structures, An International Journal (WAS Vol.22 No.4

In this paper, a shear deformation plate theory based on neutral surface position is developed for free vibration analysis of functionally graded material (FGM) plates. The material properties of the FGM plates are assumed to vary through the thickness of the plate by a simple power-law distribution in terms of the volume fractions of the constituents. During manufacture, defects such as porosities can appear. It is therefore necessary to consider the vibration behavior of FG plates having porosities in this investigation. The proposed theory is based on assumption that the in-plane and transverse displacements consist of bending and shear components, in which the bending components do not contribute toward shear forces and, likewise, the shear components do not contribute toward bending moments. The neutral surface position for a functionally graded plate which its material properties vary in the thickness direction is determined. The equation of motion for FG rectangular plates is obtained through Hamilton's principle. The closed form solutions are obtained by using Navier technique, and then fundamental frequencies are found by solving the results of eigenvalue problems. Numerical results are presented and the influences of the volume fraction index and porosity volume fraction on frequencies of FGM plates are clearly discussed.

A simple shear deformation theory based on neutral surface position for functionally graded plates resting on Pasternak elastic foundations

Meksi, Abdeljalil,Benyoucef, Samir,Houari, Mohammed Sid Ahmed,Tounsi, Abdelouahed Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.6

In this work, a novel simple first-order shear deformation plate theory based on neutral surface position is developed for bending and free vibration analysis of functionally graded plates and supported by either Winkler or Pasternak elastic foundations. By dividing the transverse displacement into bending and shear parts, the number of unknowns and governing equations of the present theory is reduced, and hence, makes it simple to use. The governing equations are derived by employing the Hamilton's principle and the physical neutral surface concept. There is no stretching-bending coupling effect in the neutral surface-based formulation, and consequently, the governing equations and boundary conditions of functionally graded plates based on neutral surface have the simple forms as those of isotropic plates. Numerical results of present theory are compared with results of the traditional first-order and the other higher-order theories reported in the literature. It can be concluded that the proposed theory is accurate and simple in solving the static bending and free vibration behaviors of functionally graded plates.

Preparation and Characterization of the New Conducting Composites Obtained From 2-Methylaniline and Aniline with Activated Carbon by In situ Intercalative Oxidative Polymerization

Faiza Chouli,Abdelghani Benyoucef,Abdelhafid Zehhaf 한국고분자학회 2014 Macromolecular Research Vol.22 No.1

A simple method was used to synthesize poly(2-methylaniline), poly(2-methylaniline-co-aniline) andpolyaniline composites with activated carbon (AC) using in situ adsorption oxidative polymerization. The resultantpolymer/activated carbon composites were characterized by UV-visible (UV-vis), Fourier transform infrared (FTIR),thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). The UV-vis and FTIR studies showed that ACparticles affect the quinoid units along the polymer backbone and indicate strong interactions between AC particlesand quinoidal sites of polymers. In addition, the room temperature conductivity values of these composites variedbetween 0.256 and 11.196 S cm-1. The electrochemical behavior of the polymers extracted from the composites hasbeen analyzed by cyclic voltammetry. Good electrochemical response has been observed for polymer films; theobserved redox processes indicate that the polymerization into AC produces electroactive polymers.

Investigation on thermal buckling of porous FG plate resting on elastic foundation via quasi 3D solution

Mohamed Mekerbi,Samir Benyoucef,Abdelkader Mahmoudi,Fouad Bourada,Abdelouahed Tounsi 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.4

The present article deals with thermal buckling of functionally graded plates with porosity and resting on elastic foundation. The basic formulation is based on quasi 3D theory. The present theory contains only four unknowns and also accommodates the thickness stretching effect. Porosity-dependent material coefficients of the plate are compositionally graded throughout the thickness according to a modified micromechanical model. Different patterns of porosity distributions are considered. The thermal loads are assumed to be uniform, linear and non-linear temperature rises through the thickness direction. The plate is assumed to be simply supported on all edges. Various numerical examples are given to check the accuracy and reliability of the present solution, in which both the present results and those reported in the literature are provided. In addition, several numerous new results for thick FG plates with porosity are also presented.

A simple shear deformation theory based on neutral surface position for functionally graded plates resting on Pasternak elastic foundations

Abdeljalil Meksi,Samir Benyoucef,Mohammed Sid Ahmed Houari,Abdelouahed Tounsi 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.6

In this work, a novel simple first-order shear deformation plate theory based on neutral surface position is developed for bending and free vibration analysis of functionally graded plates and supported by either Winkler or Pasternak elastic foundations. By dividing the transverse displacement into bending and shear parts, the number of unknowns and governing equations of the present theory is reduced, and hence, makes it simple to use. The governing equations are derived by employing the Hamilton’s principle and the physical neutral surface concept. There is no stretching–bending coupling effect in the neutral surface-based formulation, and consequently, the governing equations and boundary conditions of functionally graded plates based on neutral surface have the simple forms as those of isotropic plates. Numerical results of present theory are compared with results of the traditional first-order and the other higher-order theories reported in the literature. It can be concluded that the proposed theory is accurate and simple in solving the static bending and free vibration behaviors of functionally graded plates.

Thermal stability analysis of solar functionally graded plates on elastic foundation using an efficient hyperbolic shear deformation theory

El-Hassar, Sidi Mohamed,Benyoucef, Samir,Heireche, Houari,Tounsi, Abdelouahed Techno-Press 2016 Geomechanics & engineering Vol.10 No.3

In this research work, an exact analytical solution for thermal stability of solar functionally graded rectangular plates subjected to uniform, linear and non-linear temperature rises across the thickness direction is developed. It is assumed that the plate rests on two-parameter elastic foundation and its material properties vary through the thickness of the plate as a power function. The neutral surface position for such plate is determined, and the efficient hyperbolic plate theory based on exact neutral surface position is employed to derive the governing stability equations. The displacement field is chosen based on assumptions that the in-plane and transverse displacements consist of bending and shear components, and the shear components of in-plane displacements give rise to the quadratic distribution of transverse shear stress through the thickness in such a way that shear stresses vanish on the plate surfaces. Therefore, there is no need to use shear correction factor. Just four unknown displacement functions are used in the present theory against five unknown displacement functions used in the corresponding ones. The non-linear strain-displacement relations are also taken into consideration. The influences of many plate parameters on buckling temperature difference will be investigated. Numerical results are presented for the present theory, demonstrating its importance and accuracy in comparison to other theories.

Effect of porosity on vibrational characteristics of non-homogeneous plates using hyperbolic shear deformation theory

Fethi Mouaici,Samir Benyoucef,Hassen Ait Atmane,Abdelouahed Tounsi 한국풍공학회 2016 Wind and Structures, An International Journal (WAS Vol.22 No.4

In this paper, a shear deformation plate theory based on neutral surface position is developed for free vibration analysis of functionally graded material (FGM) plates. The material properties of the FGM plates are assumed to vary through the thickness of the plate by a simple power-law distribution in terms of the volume fractions of the constituents. During manufacture, defects such as porosities can appear. It is therefore necessary to consider the vibration behavior of FG plates having porosities in this investigation. The proposed theory is based on assumption that the in-plane and transverse displacements consist of bending and shear components, in which the bending components do not contribute toward shear forces and, likewise, the shear components do not contribute toward bending moments. The neutral surface position for a functionally graded plate which its material properties vary in the thickness direction is determined. The equation of motion for FG rectangular plates is obtained through Hamilton`s principle. The closed form solutions are obtained by using Navier technique, and then fundamental frequencies are found by solving the results of eigenvalue problems. Numerical results are presented and the influences of the volume fraction index and porosity volume fraction on frequencies of FGM plates are clearly discussed.