Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Application of three Types of Dryers Namely Tunnel, Fluidized Bed, and Fluidized Bed with Microwave for Drying of Celery, Corn, and Sour Cherry: Experiments and Modeling (TECHNICAL NOTE)
667
674
EN
Tahmasb
Hatami
Department of chemical engineering, University of Kurdistan
hatami.tahmas@gmail.com
Seyed Mostafa
Mirfatah
Chemical Engineering, University of Kurdistan
mostafamirfatah@yahoo.com
Mehrdad
Khamforoush
Department of Chemical Engineering, University of Kurdistan, 66177 Sanandaj, Iran
m.khamforoush@uok.ac.ir
In this paper, water content from celery, corn, and sour cherry were removed through tunnel, fluidized bed, and fluidized bed with microwave dryers. One day before performing the experiments, the fruits were put into a refrigerator and were ground into slices with average dimensions of 5×8×8 mm. For each experiment, 40 g of the samples were inserted in dryers. Moisture content in the samples was determined by weighting the samples using a balance. Experiments were accomplished in the air flow rate of 1 to 3 m/s, the temperature of 40 to 60 oC, and the microwave power of 180 to 540 w. Influences of these operating conditions on the drying yield were presented and discussed. This study evidenced that the fluidized bed with microwave field resulted the highest drying rate among the applied drying methods. The optimum temperature and air velocity for attaining the maximum drying performance were 60 oC and 1 m/s. In addition, the Exponential and Page’s models were used to fit the experimental data. The results showed that Page’s model had a good agreement with the experimental data.
Drying,Tunnel Dryer,Fluidized Bed Dryer,Microwave Dryer,Modeling
https://www.ije.ir/article_72297.html
https://www.ije.ir/article_72297_2a37ab2dc15dea4508509dc1e2d4c732.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Entropy-based Serviceability Assessment of Water Distribution Networks, Subjected to Natural and Man-Made Hazards
675
688
EN
Hossein
Emamjomeh
Structural Eng. Research Center, International Institute of Earthquake Engineering and Seismology (IIEES)
h.emamjome@iiees.ac.ir
M.
Hosseini
, International Institute of Earthquake Engineering and Seismology (IIEES)
hosseini@iiees.ac.ir
In this study a modified entropy-based measure is presented for evaluating the serviceability level of water distribution networks in which the hydraulic uncertainties (flow rates in pipes) as well as the uncertainties due to mechanical parameters (failure probabilities of links) are considered simultaneously. In the proposed entropy calculation method, the connectivity order of the network demand nodes is incorporated in the entropy calculations by defining a factor based on the ratio of the nodal demand to the total flow rates of all links of the network. The failure probability of the network links has been incorporated by using a penalty function based on their failure probability in any specified hazard scenario. Then, this penalty function is inserted satisfactorily in the existing hydraulic entropy function (defined by previous researchers) of the network. In this way, the effect of mechanical behavior of links is also taken into account in the hydraulic entropy function of the network, while keeping its simplicity and applicability. By calculating the entropy values of some sample networks, it has been shown that the proposed entropy-based index is an efficient tool to find the optimum hydraulic layout for designing a new system, or to make decision on the best mitigation plan for an existing network subjected to different natural and man-made hazards.
Lifelines,Hydraulic uncertainties,Failure Probabilities of Links,Informational Entropy
https://www.ije.ir/article_72298.html
https://www.ije.ir/article_72298_34ea3608c4fb1ce5022c4c318110bfd0.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Mapping CRC Card into Stochastic Petri Net for Analyzing and Evaluating Quality Parameter of Security (TECHNICAL NOTE)
689
698
EN
Hossein
Nemat Zadeh
Computer & Electrical Eng., Islamic Azad Univresity , Sari
mostafanemati_999@yahoo.com
Homayoon
Motameni
Computer & Electrical Eng., Islamic Azad Univresity , Sari
mostafa.nemati@outlook.com
Mostafa
Nemati
Computer & Electrical Eng., Payame noor University of Manjil
mostafa.manjil@gmail.com
Reza
Salimi
Computer & Electrical Eng., Tabari University of Babol
rz.sa63@gmail.com
CRC cards are unconventional method for identifying and describing classes, behavior and its responsibilities and collaborators of class. Representation of three categories of class, responsibilities and collaborators can give proper image of scenario. These cards are effective method for analyzing scenarios. With all positive features of CRC cards, of weaknesses of these cards are failure to show details of operations and failure to evaluate them. These weaknesses guide us to model and evaluate these cards using petri nets. Basis of petri nets is on graph. In addition that petri nets have mathematical structure and definitions, they have graphics. One of the other important characteristics of petri nets is their applicability which can be used for evaluating behavior and efficiency of a system. Therefore, our goal in this paper is to map CRC cards into stochastic petri net for evaluating and analyzing quality parameter of security.
CRC cards,stochastic petri net,Security Evaluation
https://www.ije.ir/article_72299.html
https://www.ije.ir/article_72299_de895bfe988ad17021d76b82c6195fe2.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Stability Assessment Metamorphic Approach (SAMA) for Effective Scheduling based on Fault Tolerance in Computational Grid
699
708
EN
BASKARAN
K
Computer Science and Engineering, Government College of Technology
baski_101@yahoo.com
Shamila
A
Computer Science and Engineering, Karunya University
shamilaa2012@yahoo.com
Grid Computing allows coordinated and controlled resource sharing and problem solving in multi-institutional, dynamic virtual organizations. Moreover, fault tolerance and task scheduling is an important issue for large scale computational grid because of its unreliable nature of grid resources. Commonly exploited techniques to realize fault tolerance is periodic Checkpointing that periodically saves the job’s state. But an inappropriate checkpointing interval prevails to delay in the job execution, and reduces the throughput. With that concern, this paper endeavors to ensure better performance on computational grid with more effective and reliable fault tolerant system using a novel Stability Assessment Metamorphic Approach (SAMA). Here, the strategy used to attain fault tolerance is by adapting the checkpoints depending on the current status and past failure information of the resources dynamically, which is being maintained in the information server. Effective scheduling process can be achieved by fault tolerance based scheduling that involves in determination of deviation rate of all nodes using some high-stability assessment constraints. This evinces the job to be accomplished within the deadline with improved throughput and paves a way for making the grid environment trust worthy.
Checkpointing,Grid Computing,fault tolerance,recovery rate,scheduling
https://www.ije.ir/article_72300.html
https://www.ije.ir/article_72300_4cb0b759c09e19991d15e79d9c453ef7.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Dimensionality Reduction and Improving the Performance of Automatic Modulation Classification using Genetic Programming (RESEARCH NOTE)
709
714
EN
karim
Hessampour
Elecrtical and Computer enginnering, Yazd University
k.hessampour@stu.yazduni.ac.ir
Alimohammad
Latif
Department of Electrical and Computer Engineering, Yazd University
alatif@yazd.ac.ir
This paper shows how we can make advantage of using genetic programming in selection of suitable features for automatic modulation recognition. Automatic modulation recognition is one of the essential components of modern receivers. In this regard, selection of suitable features may significantly affect the performance of the process. Simulations were conducted with 5db and 10db SNRs. Test and training data released from real ones recorded in an actual communication system. For performance analyzing of the proposed method a set of experiments were conducted considering signals with 2PSK, 4PSK, 2FSK, 4FSK, 16QAM and 64 QAM modulations. The results show that the selected features by the model improve the performance of automatic modulation recognition substantially. During our experiments, we also reached the suitable values and forms for mutation and crossover ratio, fitness function as well as other parameters for the proposed model.
Modulation automatic detection,Genetic programming,Entropy,multi,layer neural network perceptron,decision tree
https://www.ije.ir/article_72301.html
https://www.ije.ir/article_72301_0345449a1c707433f3dbcd5734983f33.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
A Capacitive Fed Microstrip Patch Antenna with Air Gap for Wideband Applications (RESEARCH NOTE)
715
722
EN
Arman
Azadi
Electrical and Computer Engineering, Semnan University
azadi.arman.90@gmail.com
Pejman
Rezaei
Electrical and Computer Engineering, Semnan University
prezaei@semnan.ac.ir
Mohammad Mehdi
Fakharian
Electrical and Computer Engineering, Semnan University
m_fakharian@sun.semnan.ac.ir
Mahmoud Reza
Dadras
Electrical and Computer Engineering, Semnan University
mahmoud.dadras@students.semnan.ac.ir
In this paper a microstrip antenna on a suspended substrate with capacitive feed is presented. capacitive feed is created by a slot within the rectangular patch around the feed point. The proposed antenna exhibits a much higher impedance bandwidth of about 47% (S11 < −10 dB). Effects of key design parameters such as the air gap between the substrate and the ground plane, the gap width between radiator patch and feed point, and the location of the feed point on the input characteristics of the antenna have been investigated and discussed. A prototype of the antenna is also fabricated and tested, to verify the design. Measured characteristics of the antenna are in good agreement with the simulated results.
Microstrip Patch Antenna,capacitive fed,suspended,Wideband
https://www.ije.ir/article_72302.html
https://www.ije.ir/article_72302_e40df8079fd4b1f59b76e5365dae251c.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
A New Approach for Low Voltage CMOS based on Current-controlled Conveyors
723
730
EN
Alireza
KERAMATZADEH
Electrical Engineering, University of Shahid Chamran of Ahvaz
a-keramatzadeh@scu.ac.ir
Ebrahim
Farshidi
Department of Electrical Engineering, Shahid Chamran university of Ahvaz
farshidi@scu.ac.ir
Abstract In his paper a new current-controlled conveyor (CCCII) in CMOS technology is presented. It features, low supply voltage (±0.7), low power consumption, low circuit complexity, rail to rail operation and wide range parasitic resistance ( ). The circuit has been successfully employed in a multifunction biquad filter. Simulation results by HSPICE show high performance of the circuit and confirm the validity of the proposed design technique.
Keywords Current conveyor,Filter,multifunction,biquad,Low Voltage,MOS
https://www.ije.ir/article_72303.html
https://www.ije.ir/article_72303_a0c95d52cfc7739cd4f2be91296d0fb8.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
A Robust STATCOM Controller using Particle Swarm Optimization
731
738
EN
deepa
somasundaram
EEE, Panimalar ins of tech
dee_soms123@yahoo.co.in
ranjani
M
electrical, sathyabama university
ranjani_eee@yahoo.co.in
samuel
rajesh babu
electrical, panimalar
samuel.rajeshbabu@gmail.com
In this paper, a statcom without any energy storage devices is proposed to compensate network voltage during disturbances. This statcom utilizes a matrix converter in its topology which eliminates the DC-link capacitor of conventional statcom. The modulation method for matrix converter which is used in this paper is space vector modulation. There are some methods to improve power quality for sensitive loads. In this paper, Combination of Improved multi objective Particle swarm optimization (PSO) algorithm with fuzzy membership function is used to determine the PI coefficients. The simulation results indicate the efficiency of proposed method.
Statcom,PSO,Fuzzy,voltage sag,matrix converter
https://www.ije.ir/article_72304.html
https://www.ije.ir/article_72304_66a95eda4d105ffa6630c6abc7f0af7f.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Estimating Reliability in Mobile ad-hoc Networks Based on Monte Carlo Simulation (TECHNICAL NOTE)
739
746
EN
Meisam
Yadollahzadeh Tabari
School of Computer Engineering, Shahrood University of Technology
m_tabari@shahroodut.ac.ir
Ali A
Pouyan
Computer, Shahrood University of Tech.
apouyan@shahroodut.ac.ir
Each system has its own definition of reliability. Reliability in mobile ad-hoc networks (MANET) could be interpreted as, the probability of reaching a message from a source node to destination, successfully. The variability and volatility of the MANET configuration makes typical reliability methods (e.g. reliability block diagram) inappropriate. It is because, no single structure or configuration represents all manifestations of a MANET. Thus, new methods should be developed to analyze the reliability of this new networking technology. In this paper we first introduce a simple technique for calculating reliability in MANET which is appropriate for small size of the networks. It is shown that this way is time consuming and costly in a larger network domain. Then, a heuristic method based on a Monte Carlo simulation is presented, which has less overall time consuming even for large size of the network. For a better investigation, the effect of network size (number of nodes) and probability of link existence have been studied and evaluated on network reliability for the proposed method.
mobile ad,hoc networks,Reliability,probability,Monte Carlo simulation
https://www.ije.ir/article_72305.html
https://www.ije.ir/article_72305_86d563c1b77f801e4208c61e041cfc98.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Region Completion in a Texture using Multiresolution Transforms
747
756
EN
Vinod
Kumar
ELECRONICS & COMMUNICATION, Noorul Islam Centre for Higher Education
rsvinodkumar69@yahoo.co.in
Abstract Natural images, textures and photographs are likely to be impaired by stains. As a result a substantial portion of the image remains blurred. However, a method called region completion is adopted to fill in the tainted part by using the information from the portion left unblemished by stains. A novel method to perform this operation is proposed in this paper. The three significant stages involved in the proposed work are patch size selection, matching patch identification using multiresolution transforms such as Wavelet and Contourlet Transforms; and finally minimum cost path determination. The aforesaid methods perform well for different varieties of texture images. The results obtained using the proposed method is encouraging and reasonable in some cases.
Keywords Image Processing,Texture Synthesis,Patch,Concatenation,Minimum Cost Path,Wavelet Transform and Contourlet Transform
https://www.ije.ir/article_72306.html
https://www.ije.ir/article_72306_c9bf778a63d41c965260fe398bda3833.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Synthesis of Zinc Oxide Nanostructured Thin Film by Sol- Gel Method and Evaluation of Gas Sensing Properties
757
762
EN
M.
Zameni
Nanotechnology and Advanced Materials Department, Material and Energy Research Center(MERC)
mazamene@yahoo.com
M.R.
Vaezi
Nanotechnology and Advanced Materials Department, Material and Energy Research Center(MERC)
vaezi9016@yahoo.com
Ethanol (C2H6O) sensitivity of zinc oxide (ZnO) thin film has been studied in present work. Semiconductor thin films of zinc oxide (ZnO) were deposited onto alkali-free glass substrates by the sol–gel method and dip-coating technique. The ZnO sol was synthesized by dissolving zinc acetate dehydrate in ethanol, and then adding Tetra ethanol-amine. The as-coated films were preheated at 150 ºC for 10 min and annealed at 500 ºC for 1 h in air ambiance. Fundamental features of a sensor element e.g. sensitivity, response time and recovery process has been studied using X-ray diffraction, and Scanning Electron Microscopy. The sensitivity to ethanol was desirable and Response and recovery time were only 8 sec. and 4 sec., respectively.
ZnO,Thin film,Nanostructure,Sol gel,Gas Sensor
https://www.ije.ir/article_72307.html
https://www.ije.ir/article_72307_35475184a20be14e46d5be1ec345c62f.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
AC Electrophoresis; Deposition of Ceramic Nanaoparticles on In-plane Electrodes at Low Frequencies (RESEARCH NOTE)
763
768
EN
Ehsan
Marzban
Ceramic, Material and Energy Research Center(MERC)
em13@merc.ac.ir
Babak
Raissi
Ceramic department, Material and Energy Research C, Materials and Energy Research Center, Tehran, Iran
babakraissi@yahoo.com
Reza
Riahifar
Ceramic, Material and Energy Research Center(MERC)
reza_rfr@yahoo.com
Cyrus
Zamani
Electronic, University of Barcelona
cyrus_zamani@yahoo.com
Deposition of ceramic nanoparticles (dispersed in a non-aqueous suspension) on in-plane electrodes and under the influence of AC electric fields in the frequency range of 0.01 Hz - 10 kHz is investigated. Analysis of the particle response to the applied field is a difficult task due to the mutual effect of electric- and hydrodynamic force which are present in the system. In this work, however, we show the possibility of dividing the frequency range into four domains with four distinct governing mechanisms. Possible mechanisms are suggested and dominant forces are determined for each domain. In situ optical microscopy observations as well as numerical calculations are used for three dimensional visualization of nanoparticles´ movement dispersed in liquid medium. New applications such as micro-patterning and sorting ceramic particles are introduced for the first time.
Electrophoretic deposition (EPD),AC electric field,Ceramic nanoparticle,Dielectrophoresis,AC,electroosmosis
https://www.ije.ir/article_72308.html
https://www.ije.ir/article_72308_46743a615e5b571f2024393d2e8e7407.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Synthesis of Tantalum Carbide/Boride Nano Composite Powders by Mechanochemical Method
769
774
EN
saeed reza
Bakhshi
Department of Materials Engineering, Malek-e-ashtar University of Technology
bakhshisr@ma.iut.ac.ir
Gholam hossein
Borhani
Department of Materials Engineering, Malek-e-ashtar University of Technology
borhani_g@yahoo.co.uk
Behzad
Mehdikhani
Department of Materials Engineering, Malek-e-ashtar University of Technology
beh_mehdikhani@yahoo.com
Hamid reza
Baharvandi
Department of Materials Engineering, Malek-e-ashtar University of Technology
hrbahar@ut.ac.ir
In this study, mechanochemcical process(MCP) is applied to synthesize ultrafine TaC powders. In this research, nano powder composite TaC-TaB2 was produced using mixtures of tantalum carbide and boron carbide as raw materials via mechanochemical process. The phase formation characterization during process was utilized by X-ray diffractometry (XRD). The morphology of synthesized powder was studied using scanning electron microscopy (SEM).
Mechanochemcical process(MCP),Tantalum carbide,TAC,TaB2 composite
https://www.ije.ir/article_72309.html
https://www.ije.ir/article_72309_b93d4c1b844a29ca5725eb1d3fee8c7e.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Simulation of Store Separation using Low-cost CFD with Dynamic Meshing
775
784
EN
Hamid
Parhizkar
Department of Aerospace Engineering, Malek Ashtar University
h_parhiz@yahoo.com
Sadjad
Ghasemlu
Department of Aerospace Engineering, Malek Ashtar University
sadjad_ja@yahoo.com
A.R.
Toloei
Department of Aerospace Engineering, Shahid Beheshti University
toloei@sbu.ac.ir
Mostafa
Jafari
, Shahid Beheshti University
mostafa.jafari.um@gmail.com
The simulation of the store separation using the automatic coupling of dynamic equations with flow aerodynamics is addressed. The precision and cost (calculation time) were considered as comparators. The method used in the present research decreased the calculation cost while limiting the solution error within a specific and tolerable interval. The methods applied to model the aerodynamic forces are time-dependent dynamic meshes and quasi-static methods. In the time-dependent method, a dynamic unstructured tetrahedral mesh approach using combination of spring-based smoothing and local remeshing is employed in respect of bodies motion with an implicit, second-order upwind accurate 3d Euler solver. In this method, a 6dof dynamic code is coupled with the flow solver to update the store trajectory information. In the quasi-static method, a 3-D implicit, steady state Euler solver is automatically integrated with a grid generation software and a 6dof dynamic code. Although the time-dependent method is more precise and reliable, it is not proper and appropriate for the initial design of the separation system due to its high cost. The quasi-static solution is very fast, but unable to simulate realistically because of not satisfying the problem conditions due to solution divergence as the store speed increases. The method used in the present research decreased the calculation cost while limiting the solution error within a specific and tolerable interval. In this way, the time step can be enlarged, the solution can be carried out with a few calculation points, and the solution can have considerably more speed with a limited error magnitude. Simulation of the store separation using the automatic coupling of dynamic equations with flow aerodynamics with the new Low-Cost method is the innovative aspect of this paper. To validate the solution method, the transonic store separation was simulated that agreed well with the wind tunnel test outcomes.
Store separation,Automatic Coupling,Dynamic mesh,Quasi,Static,time,dependent solution,Low,cost CFD
https://www.ije.ir/article_72310.html
https://www.ije.ir/article_72310_d4fea234395012d5d386508f34d0098a.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
An Outrun Competition of Corrosion Fatigue and Stress Corrosion Cracking on Crack Initiation in a Compressor Blade
785
792
EN
Omid
Pedram
Mechanical Engineering, University of Zanjan
omid.pedram@gmail.com
Esmaeil
Poursaeidi
Department of Mechanical Engineering, University of Zanjan, Zanjan, Iran
epsaeidi@znu.ac.ir
First row rotating blades of four axial-flow compressors were prematurely fractured. Previous investigations showed that the site atmosphere contains corrosive compounds which lead to an increase in possibility of pitting on the blades. It was also revealed that the crack was originated from two corrosion pits. Thus, this work is conducted to ascertain which of fatigue or stress corrosion cracking (SCC) mechanisms was predominant in transition of pits into initial cracks. To this end, experimental, numerical and theoretical studies are considered. Scanning Electron Microscope (SEM) and fractography of the broken blade indicate that the pits join together and make one bigger pit under SCC mechanism which reduces the failure time. 3-D models of the pitting on the blade under existing forces are analyzed by ABAQUS software. The simulation results show the location of maximum stress concentration inside one of the pits which is compatible with the location of initial SCC crack. Theoretical analysis shows stress intensity range around the pits smaller than threshold stress intensity range; thus, cracks initiated and propagated at the mouth of the pits under SCC mechanism. Then the pits join together and make one equivalent pit, so that stress intensity range reaches to threshold stress intensity range and finally crack propagates under fatigue mechanism.
Corrosion Pitting,Gas Turbine Compressor Blade,Stress Corrosion Cracking,Custom 450
https://www.ije.ir/article_72311.html
https://www.ije.ir/article_72311_deae1222081a1c4a60c9277456bbd72e.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
An Analytical Model for Flame Propagation through Moist Lycopodium Particles with Non-unity Lewis Number
793
802
EN
Hossein
Beidaghy Dizaji
Engineering Department, The Australian National University (ANU)
u5930615@anu.edu.au
Farzad
Faraji Dizaji
, Iran University of Science and Technology (IUST)
farzadfaraji@mecheng.iust.ac.ir
Seyed alireza
Mostafavi
Department of Mechanical Engineering, Faculty of E, Arak University
a-mostafavi@araku.ac.ir
In this investigation, the structure of one-dimensional flame propagation in uniform cloud of volatile organic particles has been analyzed in which the structure of flame is divided into three zones. The first zone is preheat zone which is divided into three subzones itself. In first subzone (heating), particle cloud heated until the moisty particles reach to vapor vaporization temperature. In the next subzone (drying), particle moisture comes out, and in the final subzone the pyrolysis phenomena happens. The second zone is reaction zone, and the last zone is post-flame zone. In this research, an analytical method is used in order to solve the governing equations of particle cloud combustion in aforementioned zones. The overall investigation of this study leads to a non-linear burning velocity correlation. Consequently, the results show that increase in particle moisture content, equivalence ratio and Lewis number causes to increase in devolatization rates which culminate to increase in flame temperature and burning velocity.
Analytical model,Lycopodium particle,Moisture effect,Lewis number,Flame temperature,Burning Velocity
https://www.ije.ir/article_72312.html
https://www.ije.ir/article_72312_6a7d6bb691ba4557709620709d139063.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
The Investigation of Modelling Material Behavior in Autofrettaged Tubes Made from Aluminium Alloys
803
810
EN
karim
aliakbari
Department of Mechanical Engineering, Faculty of Montazeri, Khorasan Razavi Branch,Technical and Vocational University (TVU), Mashhad, Iran
karimaliakbari@yahoo.com
Normal 0 false false false EN-US X-NONE AR-SA The ratio of compression yield strength to the initial tensile yield strength is called Bauschinger effect factor, BEF. A nonlinear strain hardening mathematical model is proposed for 7075 aluminium alloy (A7075). Uniaxial tension-compression experimental data are used to figure out a suitable model to study the BEF. Hence, uniaxial tension-compression tests on some specimens having 12.5 mm and 6 mm diameters were carried out by an Instron servohydraulic machine and were compared. In this paper several factors including Young’s modulus, the amount of offsets to determine yield point and BEF were studied. Besides, BEF in the aluminium tubes made from alloys of A5083 and A7075 were compared. This model will be employed to predict residual stress and fatigue life in autofrettaged tubes.
Thick,walled tube,Autofrettage,nonlinear mathematical model,Bauschinger effect,Aluminum alloys
https://www.ije.ir/article_72313.html
https://www.ije.ir/article_72313_eb5111a14f442a84c7b8795e2d4ea410.pdf
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
27
5
2014
05
01
Drying Kinetics of Muscat Grapes in a Solar Drier with Evacuated Tube Collector
811
818
EN
Subramanian
C.V
Architecture, Periyar Maniammai University
cvsubra@gmail.com
Neelamegam
P
School of Electrical and Electronics Engg, SASTRA University
neelkeer@gmail.com
Umayal Sundari
AR
Physics, A.V.V.M Sri Pushpam College
umacvs@rediffmail.com
A solar drier assisted with evacuated tube collector is designed and developed to study and examine the drying Kinetics of muscat grapes in Thanjavur, Tamilnadu, India. During the drying period, temperature at various places, relative humidity, wind velocity and mass of the sample are measured on hourly basis. The outlet temperature of the collector and temperature within the chamber varies from 74-130 ºC and 50-87 ºC respectively, while the ambient temperature ranges from 29.5-33.2 ºC. Solar insolation recorded during these days ranges from 155.6-1115 W/m2. The designed drier takes 14 hours to lessen the moisture content of muscat grapes from 78% to 9.5% (wb) to ensure safe storage. It is found that the whole drying process exists in falling-rate period. The maximum drier efficiency for muscat grapes is found to be 29.92% during the drying period. Six thin-layer drying models have been used to fit the experimental moisture ratio obtained for muscat grapes by nonlinear regression analysis using IBM SPSS 20 statistical package. According to the results, Page model shows a good fit with highest correlation (R2 = 0.991), lowest reduced chi-square (χ2 = 0.001) and lowest root mean square error (RMSE = 0.0297).
Solar Drier,Evacuated Tube Collector,Muscat Grapes,Drier Efficiency,Thin,Layer Drying Model,Moisture ratio
https://www.ije.ir/article_72314.html
https://www.ije.ir/article_72314_074632f3d19751e66ed886af43476019.pdf