eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
107
114
71840
A Study on Plant Polymer: Pectin Production and Modification (RESEARCH NOTE)
Iran Alemzadeh
alemzadeh@sharif.ir
1
Chemical Engineering, Sharif University of Technology
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 %.
https://www.ije.ir/article_71840_356ee9636840e67dc9242c1916229028.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
115
120
71842
Environmental Impact of Fossil Fuel Utilization in Neka Thermal Power Plant
M. Asadi
asadi.mostafa@gmail.com
1
S.Jafar Mehdizadeh
jfar_mehdizadeh@yahoo.com
2
Ghasem Najafpour
ije.editor8@gmail.com
3
Civil Engineering, University of Mazandaran
Industrial Engineering, Mazandaran University of Science and Technology
Biochemical & Chemical Engineering, Noshirvani University of Technology, Babol
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.
https://www.ije.ir/article_71842_99fdce05e0f9cc1d12e07114694b2fb6.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
121
132
71843
A Novel Temporal-Frequency Domain Error Concealment Method for Motion Jpeg
Mohsen Ashourian
mohsena@ieee.org
1
Sepideh Amoozeidi
szeidi@yahoo.com
2
Payman Moallem
p_moallem@eng.ui.ac.ir
3
Electerical Engineering, Islamic Azad university of Majlesi Branch
, Isfahan Telecommunication Company (TCE)
Department of Electrical Engineering, Faculty of Engineering
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.
https://www.ije.ir/article_71843_b988357ea4c8dc00fe853befe2b78811.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
133
138
71845
Preparation of Cobalt Oxide/Zinc Oxide Nanocomposite
S. Alibeigi
salibeigi@yahoo.com
1
M.R. Vaezi
vaezi9016@yahoo.com
2
L. Nikzad
leila_nikzad@yahoo.com
3
A. Esmaielzadeh Kandjani
mstgahmad@gmail.com
4
materials department, KNTU
Nanotechnology and Advanced Materials Department, Material and Energy Research Center(MERC)
Research Center of Advanced Materials, Merc
Applied Science, RMIT - RMIT University
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.
https://www.ije.ir/article_71845_a91c606002eca76d53440ed34f8103d0.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
139
146
71846
The Influence Of Process Control Agent (P.C.A)’S State on Expedition of Mechanical Alloying of Anostructure Tial(Γ) Alloy
rasoul Azazari.khosroshahi
rakhosroshahi@sut.ac.ir
1
Farshad Abbasi Nargesi
farshadabbasi60@yahoo.com
2
Naghi parvini.ahmadi
parvini@sut.ac.ir
3
, Sahand Univ. of Technology
Materials and Metallurgical Engineering Department, Sahand Univ. of Technology
Materials Eng., Sahand University of Technology
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.
https://www.ije.ir/article_71846_04473ff2cd36284140e3d28d6153861b.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
147
156
71848
Studying the Effect of Productive Factors on Synthesis of Anostructure Tial (Γ) Alloy By Mechanical Alloying
rasoul Azazari.khosroshahi
rakhosroshahi@sut.ac.ir
1
Farshad Abbasi Nargesi
farshadabbasi60@yahoo.com
2
Naghi parvini.ahmadi
parvini@sut.ac.ir
3
, Sahand Univ. of Technology
Materials and Metallurgical Engineering Department, Sahand Univ. of Technology
Materials Eng., Sahand University of Technology
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.
https://www.ije.ir/article_71848_8ab6645a3dbf7ed507bff509203640e9.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
157
168
71850
Dynamic Analysis of Moving Cables with Variable Tension and Variable Speed
A. Alipour
hasnomail@ije.ir
1
M. H. Korayem
hkorayem@iust.ac.ir
2
Mechanical Engineering, Iran University of Science & Technology
Mechanical Engineering, Iran University of Science & Technology
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
https://www.ije.ir/article_71850_b24a345d0759ecd34d51c59abad54c7c.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
169
178
71852
An Elasticity Solution for Static Analysis of Functionally Graded Curved Beam Subjected to a Shear Force
Seyed Rasoul Atashipour
atashipour@iust.ac.ir
1
asghar nasr
a_nasr@iust.ac.ir
2
Mohammad Fadaee
fadaee@iust.ac.ir
3
Mechanical Engineering, Iran University of Science and Technology (IUS
Railway Engineering, Iran University of Science and Technology (IUS
Mechanical Engineering, Iran University of Science and Technology (IUS
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.
https://www.ije.ir/article_71852_912bf634942cc9767a4376e42d4134a6.pdf
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2010-05-01
23
2
179
192
71854
Buckling Analysis of Thin Functionally Graded Rectangular Plates with two Opposite Edges Simply Supported
Alireza Saidi
a_r_saidi@yahoo.com
1
Seyyed Mohammad Kazerouni
sm_kazerooni@yahoo.com
2
M. Mohammadi
m.mohammadi@mail.urmia.ac.ir
3
Mechainical Engineering, Shahid Bahonar University of Kerman, Kerman
Mechanical Engineering, Islamic Azad University, Branch of Khomeinishahr
Civil Engineering, Urmia University
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.
https://www.ije.ir/article_71854_0855f38ff9f237e5cf91049ccd6e9e06.pdf