@article { author = {Alemzadeh, Iran}, title = {A Study on Plant Polymer: Pectin Production and Modification (RESEARCH NOTE)}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {107-114}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Abstract Pectin from two different plant sources: apple and sugar beet was studied. Apple pectinwas modified by chemical treatments such as: acid, alkali and ammonia, so as to obtain an ester levelequal to or less than 50 %, which is described as low methoxyl (LM) pectin. LM pectin form gelswith significant characteristic. In this study, de-esterification of apple pectin with acid treatmentresulted in gel specification with higher molecular weight and viscosity. Acid treatment resulted inpectin with average molecular weight of 32000 Dalton. Pectin was extracted from sugar beet pulp byacid and alkali treatments. The quality of gel formation and water uptake was improved using sugarsource (glucose), CaCl2 and peroxidase enzymes. The optimal levels of materials in formation of gelwith high water absorption capacity were: Glucose 5 %, Pectin 15 %, CaCl2 80mg/g, and enzyme unit170 U/g pectin. The level of ingredients responsible for gel hardness was related to sugar content(glucose) of 15 %.}, keywords = {}, url = {https://www.ije.ir/article_71840.html}, eprint = {https://www.ije.ir/article_71840_356ee9636840e67dc9242c1916229028.pdf} } @article { author = {Asadi, M. and Mehdizadeh, S.Jafar and Najafpour, Ghasem}, title = {Environmental Impact of Fossil Fuel Utilization in Neka Thermal Power Plant}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {115-120}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Carbon dioxide causes green house effect and has been considered as a pollutant source forsafe environment. Since combustion of fossil fuel may create tremendous amount of carbon dioxide,detecting any pollutant sources would be important to eliminate the origin of pollution sources.Evaluation of smoke dispersion generated by the power plant utilizing fossil fuel is the objective of thispaper. The concentration of NOx and SOx in the soil till a distance of 15 km from Neka power plant,have been analyzed. The maximum concentrations of SOx and NOx in the distance of 2.5 to 4 km fromthe power plant were 0.13 and 0.36 ppm, respectively. Replacement of fossil fuel (fuel no. 6, Mazout) bynatural gas may increase NOx concentration in the atmosphere; however the use of natural gas wasrecommend by environmental protection agencies as clean fuel. Use of natural gas may not be an actualsolution for prevention of NOx pollution.}, keywords = {}, url = {https://www.ije.ir/article_71842.html}, eprint = {https://www.ije.ir/article_71842_99fdce05e0f9cc1d12e07114694b2fb6.pdf} } @article { author = {Ashourian, Mohsen and Amoozeidi, Sepideh and Moallem, Payman}, title = {A Novel Temporal-Frequency Domain Error Concealment Method for Motion Jpeg}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {121-132}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Motion-JPEG is a common video format for compression of motion images with highquality using JPEG standard for each frame of the video. During transmission through a noisychannel some blocks of data are lost or corrupted, and the quality of decompression frames decreased.In this paper, for reconstruction of these blocks, several temporal-domain, spatial-domain, andfrequency-domain error concealment methods are investigated. Then a novel method is proposed forrecovery of channel errors with a mixture of temporal-domain and frequency-domain errorconcealment methods. To reconstruct the missed blocks in the proposed novel method, when twosuccessive frames are similar, a proposed two phase block matching algorithm is performed intemporal-domain. When two successive frames are different, our proposed method reconstructs themissed block by the estimation of DC and AC coefficient, in frequency-domain. The proposedmethod and the other similar methods are simulated for different noise and quality factors. The resultsof quality measurements are indicated that in all tested video sequences, the proposed method showshigher quality in reconstruction of missed blocks.}, keywords = {}, url = {https://www.ije.ir/article_71843.html}, eprint = {https://www.ije.ir/article_71843_b988357ea4c8dc00fe853befe2b78811.pdf} } @article { author = {Alibeigi, S. and Vaezi, M.R. and Nikzad, L. and Esmaielzadeh Kandjani, A.}, title = {Preparation of Cobalt Oxide/Zinc Oxide Nanocomposite}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {133-138}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Cobalt Oxide/ Zinc Oxide nanocomposite was synthesized by dropwise addition ofCo(NO)3.6H2O and Zn(NO3)2.4H2O solutions to KOH solution at different temperatures followed bycalcination at 300ºC for 4 h. The morphology and structure of nanoparticles and the influence oftemperature on particle size were studied using scanning electron microscopy (SEM) and X-RayDiffraction (XRD). Minimum particle size was obtained before calcination at 70ºC. In addition, thespherical, semispherical and flake-shaped nanoparticles were observed at ambient temperature. Onthe other hand, Co(OH)2 was transformed to Co3O4, ZnO flakes were eliminated, and particle sizechanged during calcination. Synthesized samples at 50ºC and 70ºC showed an increase size aftercalcinations; however, elimination of flakes during calcination caused particle size reduction forsynthesized sample at ambient temperature.}, keywords = {}, url = {https://www.ije.ir/article_71845.html}, eprint = {https://www.ije.ir/article_71845_a91c606002eca76d53440ed34f8103d0.pdf} } @article { author = {Azazari.khosroshahi, rasoul and Abbasi Nargesi, Farshad and parvini.ahmadi, Naghi}, title = {The Influence Of Process Control Agent (P.C.A)’S State on Expedition of Mechanical Alloying of Anostructure Tial(Γ) Alloy}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {139-146}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this research, the effect of two process control agent: methanol (liquid state) and stearicacid (solid state) on mechanical alloying process of Ti and Al with equal at%(Ti50Al50) wereinvestigated. Phase transformation at presence of two PCA was: at first, powder mixture wastransformed to a metastable solid solution of Al in Ti lattice (disordered hcp) and then transformed toamorphous phase with increasing the alloying time. The results showed that the state and type of PCAis effective in expedition of mechanical alloying process. The metastable solid solution phase (dis.hcp) at presence of methanol was achieved more quickly than stearic acid was used. Changes in grainsize, lattice strain, weight recovered and impurity content of milling parameters at presence of twodifferent PCA were studied. At last with annealed of last product of alloying, the TiAl(γ) phase withhigh purity and nanostructured form were produced.}, keywords = {}, url = {https://www.ije.ir/article_71846.html}, eprint = {https://www.ije.ir/article_71846_04473ff2cd36284140e3d28d6153861b.pdf} } @article { author = {Azazari.khosroshahi, rasoul and Abbasi Nargesi, Farshad and parvini.ahmadi, Naghi}, title = {Studying the Effect of Productive Factors on Synthesis of Anostructure Tial (Γ) Alloy By Mechanical Alloying}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {147-156}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this research, the Planetary mill was used for mechanical alloying (MA) of Ti and Alpowder mixture with equal at% (Ti50Al50). The effect of various factors, such as process control agent(PCA), speed of rotation of vial and ball-to-powder weight ratio, on process were studied and the bestcondition to synthesis the alloy was determined. Study on X-ray diffraction (XRD) patterns showedthat at primary hours of milling, the powder mixture transmitted to metastable solid solution phaseand with increasing the alloying time, that phase transformed to an amorphous, ultra fine grain andhomogenous phase. Changes in grain size, lattice strain and impurity content during alloying andvarious condition were studied and at last with annealing of the product, the TiAl (γ) phase with highpurity and nanostructered form was produced.}, keywords = {}, url = {https://www.ije.ir/article_71848.html}, eprint = {https://www.ije.ir/article_71848_8ab6645a3dbf7ed507bff509203640e9.pdf} } @article { author = {Alipour, A. and Korayem, M. H.}, title = {Dynamic Analysis of Moving Cables with Variable Tension and Variable Speed}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {157-168}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Dynamic Analysis of an axially moving cable with time dependent tension and velocity isstudied in this paper. Tension force and the moving speed are assumed to be harmonic.It is found that there exists a specific value of speed in which natural frequency of the system approacheszero. This specific speed for such a critical condition is called critical speed and it will be proved thatincreasing the cable tension increases critical speed of the moving cable. Multiple-Scales perturbationtechnique is used to discretize the nonlinear equations of motions. Critical speeds are then obtained inwhich vibrations of motion become unstable. Stability analysis is carried out for different sets ofexcitation frequency. Dynamic responses of the system are calculated using Galerkin’s method. Acomprehensive parametric study is carried out and effects of different parameters like the moving speedand tension force on the responses are studied both in frequency and time domain}, keywords = {}, url = {https://www.ije.ir/article_71850.html}, eprint = {https://www.ije.ir/article_71850_b24a345d0759ecd34d51c59abad54c7c.pdf} } @article { author = {Atashipour, Seyed Rasoul and nasr, asghar and Fadaee, Mohammad}, title = {An Elasticity Solution for Static Analysis of Functionally Graded Curved Beam Subjected to a Shear Force}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {169-178}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this paper, using 2-D theory of elasticity, a closed-form solution is presented for stressdistributions and displacements of a FG curved beam under shear force at its free end. The materialproperties are assumed to vary continuously through the radial direction based on a simple power lawmodel and Poisson’s ratio is supposed to be constant. In order to verify the solution, it is shown that allstress and displacement relations are converted to those of a homogenous curved beam when theinhomogeneity constant approaches zero. The effects of inhomogeneity on stress distributions areinvestigated. It is shown that specified stress distribution profiles can be obtained by changing thevariation of volume fraction of constituents. It is observed that for a specific value of inhomogeneityconstant, a proper stress distribution along the radial direction is obtained for designing purposes.}, keywords = {}, url = {https://www.ije.ir/article_71852.html}, eprint = {https://www.ije.ir/article_71852_912bf634942cc9767a4376e42d4134a6.pdf} } @article { author = {Saidi, Alireza and Kazerouni, Seyyed Mohammad and Mohammadi, M.}, title = {Buckling Analysis of Thin Functionally Graded Rectangular Plates with two Opposite Edges Simply Supported}, journal = {International Journal of Engineering}, volume = {23}, number = {2}, pages = {179-192}, year = {2010}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this article, an exact analytical solution for thermal buckling analysis of thin functionallygraded (FG) rectangular plates is presented. Based on the classical plate theory and using the principle ofminimum total potential energy, the stability equations are obtained. Since the material properties in FGmaterials are functions of the coordinates (specially the thickness), the stability equations are coupled interms of in-plane and out-of plane displacements. Introducing a new analytical method, the coupledstability equations are converted into independent equations. It is assumed that the plate is simplysupported on two opposite edges and has arbitrary boundary conditions along the other edges, so theLevy solution is considered. Two types of thermal loads, uniform and non-linear temperature risethrough the thickness are considered as the loading conditions. Finally, the effect of aspect ratio,thickness to side ratio, index of FGM and boundary conditions on the critical buckling temperature ofFG rectangular plates are discussed in details.}, keywords = {}, url = {https://www.ije.ir/article_71854.html}, eprint = {https://www.ije.ir/article_71854_0855f38ff9f237e5cf91049ccd6e9e06.pdf} }