Publications

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Volume 3, (May–June 2015)

Composite Differential Evolution Algorithm: Mixed Variable Structural Optimization Problem

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 3–8

A. Hammoudi, F. Djeddou

 

Abstract

Differential evolution (DE) has been widely applied to solve global optimization problems. As we know, the choice of trial vector generation strategies and the control parameters values such as: crossover probability CR, scaling factor F, population size NP, plays a very important role on the DE performance. In the present work, we applied an extended version of DE. This method uses three trial vector generation strategies and three control parameter settings. It randomly combines them to generate trial vectors. To investigate the robustness of CoDE in solving highly constrained mixed variable structural optimization problems, we have chosen to optimize the dimensions of a helical spring subjected to a constant compressive load axially guided. In this case the objective function is to minimize the volume of the spring. A program using CoDE has been developed and implemented in MATLAB. The obtained results in this paper were compared with those existing in the literature. They demonstrate the effectiveness and robustness of the applied method.

 

Keywords: Composite differential evolution; Global optimization; Mixed variables.

 

Received
  Received in revised
03 December 2014
  23 March2015
 

The mechanical properties of Zigzag carbon nanotube using the energy‒ equivalent model

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 9–14

Mohamed Zidour, Lazreg Hadji, Mokhtar Bouazza, Abdelouhed Tounsi and El Abess Adda Bedia.

 

Abstract

This paper is concerned with the use of the energy-equivalent model to investigate the mechanical properties of Zigzag single and Multi-walled carbon nanotubes. The equivalent Young’s modulus and shear modulus for both zigzag single (SWCNTs) and Multi (MWCNTs) walled carbon nanotubes  are derived by combining the continuum mechanics and molecular mechanics. The analytical solution is derived using the principle of molecular mechanics when the total system potential energy associated with both stretching and angular variations is obtained and the strain energy can be obtained based on continuum mechanics. The values of the effective Young’s moduli of Multi- walled carbon nanotube depend on the number of tube layer. The varying range of moduli reflects the physics change in the true lattice rigidity, this change is caused by Van-der-Waals force interactions between adjacent tubes. The influence of chirality of Zigzag carbon nanotube and number of layer is studied and discussed. The research work reveals the significance of the chirality of Zigzag nanotube and number of layer on the Young’s modulus, shear modulus and Poisson’s ratio. Young’s modulus and shear modulus for  single and Multi-walled zigzag nanotubes increase with increasing of chirality nember, but the variation trend of Poisson’s ratios is reverse. On the other hand, Young’s modulus and shear modulus of zigzag nanotubes decrease with increasing of nember of layer.

 

Keywords: Nanotube, Chirality, Zigzag, Young’s modulus, Energy, Multi-walled.

 

Received

 Received in revised
03 December 2014
23 March 2015
 

Triaxial Compression Tests of Soil Reinforced with Fibers

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 15–20

K. Negadi, A. Arab, M. Kamal Elbokl, F. Setti

 

Abstract

This  paper  investigates  the  effects  of  vegetation  on  the  stability  of   soil  using  the  triaxial  compression  test .In  order  to evaluate influences of roots on soil shear strength an experimental investigations on the stress-strain behaviour of chlef soil, a  monotonic drained and undrained  triaxial laboratory  tests  that  were  carried  out  on  reconstituted  specimens  at  various confining  pressure  (σc’=50, 100, 200, 300, 400  KPa) , and  a  constant  relative  density  (Dr = 50 %).Reinforcement  of  soil  by fibrous roots is crucial for preventing soil erosion and degradation. Therefor we investigated soil reinforcement by roots of acacia pycnantha planted in the area of chlef where shallow landslides and slope instability are frequent. These Roots were distributed in soil in two forms: vertically and horizontally. The monotonic Test results showed that roots have more impacts on the soil shear strength than the friction angle; and the presence of roots in soil substantially increased the soil shear strength. Also the results showed that the contribution of roots on the shear strength mobilized increases with increase in the confining pressure

 

Keywords: Drained, Monotonic, Roots, Shear Strength, Triaxial test.


Received
 Received in revised
03 December 2014
23 March 2015
 

Studies on the Properties of Cellulose Fibers-Reinforced Thermoplastic Starch Composites

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 21–25

H. L. Boudjema and H. Bendaikha

 

Abstract

Green composites have gained renewed interest as environmental friendly materials and as biodegradable renewable resources for a sustainable development; in this study, cellulosic fibers are obtained from raw plant material such as Atriplex Halimus plant (found in Oran, Algeria).  These fibers have been used as reinforcement for thermoplastic starch in order to improve its different properties. The composites were prepared by solution casting method from corn starch plasticized with glycerol as matrix which was reinforced with micro-cellulosic fibers with fiber content ranging from 0 to 15% (wt/wt of fibers to matrix). Physical properties of composites were determined by mechanical tensile tests and thermogravimetric analysis. The results showed that higher fibers content raised the elastic modulus and the temperature of degradation when compared to the non-reinforced thermoplastic starch. Optical microscopy revealed a good adhesion between matrix and fibers. The prepared composites present an environmentally safe material for different applications and can be one of the strongest drivers for sustainable products.

 

Keywords: thermoplastic starch; Cellulose fibers; Mechanical properties; Thermal properties.


   Received
 Received in revised
03 December 2014
23 March 2015
 

Effect of a Composite Aggregate on the Durability of Mortars

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 26–31

M.T. Gouasmi, A.S. Benosman,  H. Taibi, M. Belbachir and Y. Senhadji

 

Abstract

In this study, the reutilization of plastic waste from PET bottles (polyethylene terephthalate) is suggested, in order to design a composite material (PET- siliceous sand). This composite material will subsequently give a lightweight aggregate WPLA. Technical solutions to some specific and massive applications in the field of eco-friendly construction, through the reduction of plastic waste, are proposed in the present study. The effects of this material on the behavior of an industrial screed are investigated through the replacement of conventional aggregates (calcareous sand) with this material at rates of 0, 25, 50, 75 and 100 % by weight, vis-a-vis the acid - alkaline attack , and subsequently recommend some possible specific uses of this screed and also of the composite material. Very encouraging positive results have been obtained, concerning the application of this composite material, in the field of construction. A microstructural analysis of screed mortars, conceived after exposure to acid - alkaline attack, was carried out by infrared FTIR and SEM analysis.

 

Keywords: Composite aggregate design; Durability; FTIR; Mechanical strength; WPLA.

 

Received
    Received in revised
03 December 2014
23 March 2015
 

Aging effect of synthetic sea water after fatigue in tension of a glass epoxy composite

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 32–37

Y. Menail, A. El Mahi, M. Assarar and B. Redjel

 

Abstract

The study of the fatigue behavior tensile in sea water is based on the stress strain relationship. The evolution of Young’s modulus and strain based on fatigue and aging, gives us an idea about the resistance of the material. The effect of the increased number of fatigue cycles ranging from 100-50000 cycles and aging times of the order of 100, 500 and 1000 hours, is shown by a loss in rigidity.

 

Keywords: Aging, Sea water, Fatigue, Tension, Gglass epoxy.


Received
 Received in revised
03 December 2014
23 March 2015
 

Elaboration of Thermostructural Composites by Chemical Vapor Infiltration (CVI)

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 38–42

M. Athmani, M. Boulekra, A. Benfoughal, N. Sassane and A. Grid

 

Abstract

Space and aicraft applications need to have light but not brittle materials at high temperatures. Ceramic martix composites are interesting candidates for such applications because they have a low density, tolerant to the damage and have good mechanical properties compared to metal alloys at high temperatures. CMCs are made with long fiber fabric embedded in a ceramic matrix deposited by the chemical vapor infiltration (CVI). This work provides a general overview on the chemical vapor infiltration technology to be used to carry out our research project. The aim of this project is the elaboration of ceramic matrix composite SiC-SiC by CVI and the characterization of their mechanical and physical properties.

 

Keywords: Space; aicraft; CMCs; elaboration; Porosity; characterization; SiC.

 

Received 
 Received in revised
03 December 2014
23 March 2015
 

Preparation of Material Composite Chitosan / Hydroxyapatite

Original Research Article

Journal of Chemistry and Materials Research Vol. 3, 2015, 43–47

O. Sebaoui and H.  Maachou

 

Abstract

The aim of this work was to develop a novel Chitosan/Hydroxyapatite composite biomaterial, using chitosan biopolymer as a matrix and hydroxyapatite as a mineral charge. First, HA particles have been synthesized by precipitation in aqueous solution. Second, composite microspheres (Cs/HA) have been prepared by emulsification cross-linking process, using dispersed HA powder in chitosan solution with different ratios as aqueous phase, paraffin oil as oil phase and glutaraldehyde as a cross-linking agent. The as-prepared powders and the novel class of composites have been characterized by X-ray diffraction (XRD) and Fourier-transformed infrared spectroscopy (FTIR). The results showed that all the peaks of standard HA were present in that of synthesized one. The FTIR spectrum of non-loaded chitosan microspheres presents the characteristic peaks of chitosan. In addition, the structural analysis of the composite microspheres (Cs/HA) indicates that the intensity of peaks is, in general, proportional to the amount of HA in these composites.

 

Keywords:  Chitosan, Hydroxyapatite, Microsphere, Composite, Biomaterial.

 

Received
 Received in revised
03 December 2014
23 March 2015