eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1473
1479
73300
Interpreting the CO2 adsorption on functionalized organic group of IRMOF-1: A B3LYP DFT based study
M Arjmandi
mehrzad.arjmandi89@gmail.com
1
M Pourafshari Chenar
mpourafsharich@um.ac.ir
2
M Peyravi
m.peyravii121@nit.ac.ir
3
M Jahanshahi
m.jahanshahii10@nit.ac.ir
4
A Arjmandi
abolfazlarjmandi91@gmail.com
5
A Shokuhi Rad
a.shokuhirad12@gmail.com
6
Chemical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
Chemical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
Membrane Research Group, Nanotechnology Institute, Babol Noshirvani University of Technology, Shariati Ave.,Babol, Iran
Membrane Research Group, Nanotechnology Institute, Babol Noshirvani University of Technology, Shariati Ave.,Babol, Iran
Department of Chemical Engineering, Mazandaran University of Science and Technology, Mazandaran, Iran
Department of chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran
Density Functional Theory (DFT) calculations techniques in terms of energetic and electronics properties are used to study CO2 adsorption in NH2-, OH-, COOH-, Br- and Cl-functionalized IRMOF-1. Geometry optimization, density of states (DOS), and energy analyses were performed to investigate the adsorption phenomenon. First, we examined the geometrical as well as the electronic structures of functionalized IRMOF-1 (actually functionalized H2BDC as representative section) before and after interaction with CO2, in order to compare and comprehend the relationship between their chemical structure and their related properties. The binding properties have been calculated and analyzed theoretically for pristine H2BDC and X-H2BDC as well as their complex forms with CO2 molecule in terms of binding energies, band structures, total density of states, and Mulliken charges. The finding showed larger interaction energy in COOH-H2BDC (-22.3125 kJ/mol) and somewhat in OH-H2BDC (-12.8625 kJ/mol) and NH2-H2BDC (-12.6000 kJ/mol) complexes compared to less interaction energies in Br-H2BDC (-10.2375 kJ/mol) and Cl-H2BDC (-6.0375 kJ/mol) complexes. The type of interaction between CO2 with pristine H2BDC and X-H2BDC was studied with understanding the HOMO and LUMO energies.
https://www.ije.ir/article_73300_68af936ad128b995e9f7e66ecc06b70c.pdf
IRMOF
1
CO2 capture
Functionalization
DFT
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1480
1486
73283
The Effect of Air Fuel Ratio and Temperature on Syngas Composition and Calorific Value Produced from Downdraft Gasifier of Rubber Wood-Coal Mixture
T Tiara
tyara_eg@yahoo.co.id
1
T. E Agustina
tuty_agustina@unsri.ac.id
2
M Faizal
mfaizal1405@gmail.com
3
Chemical Engineering Magister Program, Faculty of Engineering, Universitas Sriwijaya, Palembang 30139, Indonesia
Chemical Engineering Department, Faculty of Engineering, Universitas Sriwijaya, Palembang 30139, Indonesia
Chemical Engineering Department, Faculty of Engineering, Universitas Sriwijaya, Palembang 30139, Indonesia
Rubber wood (Ficus elastica) is one the biomass waste that can be used as raw material for a gasification process and has a calorific value of 4,069 cal/gram. Gasification is a process to convert a solid fuel to syngas (CO, CH4, and H2) through a combustion process using limited air between 20% to 40% of air stoichiometry. Depending on the direction of airflow, the gasifiers are classified as updraft, downdraft, and cross-flow. The downdraft type of gasifier produces a lower tar content than updraft type. The gasification of rubber wood and rubber wood-coal mixture were carried out in this research. The purpose of the research is to determine the effect of Air Fuel Ratio (AFR) and temperature on calorific value and composition of syngas by using a downdraft gasifier. The variations of AFR were 0.64, 0.95, and 1.26. The temperature of gasification was varied between 600ºC-1000ºC. The result showed that the percentage of CO, H2, and CH4 decreased with increasing of AFR, so decreasing the calorific value. The calorific value of syngas increased along with the temperature. The use of coal in the gasification process can maintain stable combustion the temperatures and increase the syngas produced. The best-operating conditions in the research occurred at AFR of 0.64, the temperature of 800ºC and use of coal as a stabilizer. At this condition, the percentage of syngas of 35.95% of CO, 15.95% of H2, 9.38% of CH4, and caloric value of 9,420 MJ/m3 was obtained.
https://www.ije.ir/article_73283_035e67c29812ef57df087a90598bfefd.pdf
Rubber wood
gasification
Downdraft gasifier
Syngas
LHV
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1487
1497
73284
A Prioritization Model for HSE Risk Assessment Using Combined Failure Mode, Effect Analysis, and Fuzzy Inference System: A Case Study in Iranian Construction Industry
A Ardeshir
ardeshir@aut.ac.ir
1
P Farnood Ahmadi
pm.farnood@aut.ac.ir
2
H Bayat
bayat94@aut.ac.ir
3
Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran
Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran
Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran
The unavailability of sufficient data and uncertainty in modeling, some techniques, and decision-making processes play a significant role in many engineering and management problems. Attain to sure solutions for a problem under accurate consideration is essential. In this paper, an application of fuzzy inference system for modeling the indeterminacy involved in the problem of HSE risk assessment is presented. For this purpose, Failure Mode and Effect Analysis, one of the most practical techniques in reliability programs in HSE risk assessment is integrated with Fuzzy Inference System. The proposed model is executed according to the Mamdani algorithm and fuzzy logic toolbox of MATLAB software. With respect to a case study, a comparison between the proposed model and common FMEA risk assessment approach is made for prioritization of HSE risks. Based on the proposed model, falling and slipping of workers is the first serious risk (RPN= 0.7938) and inconsiderable risk is skin injury (RPN= 0.0223). Ultimately, by applying the method on a case study, the results indicate that the proposed model by considering economic aspects as an intelligent risk evaluation tool provides more detailed and precise results.
https://www.ije.ir/article_73284_d82673d474337bfffdb58c61ed31697c.pdf
FMEA
Fuzzy inference system
HSE risk assessment
Mamdani algorithm
Construction Industry
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1498
1504
73285
Comparison of Two Computational Microstructure Models for Predicting Effective Transverse Elastic Properties of Unidirectional Fiber Reinforced Composites
W. Lin
wangqinglin@stu.haut.edu.cn
1
H. Wang
huiwang@haut.edu.cn
2
Y. Zhang
yuxuanzhang@stu.haut.edu.cn
3
College of Civil Engineering & Architecture, Henan University of Technology, Zhengzhou, China
College of Civil Engineering & Architecture, Henan University of Technology, Zhengzhou, China
State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, China
Characterization of properties of composites has attracted a great deal of attention towards exploring their applications in engineering. The purpose of this work is to study the difference of two computational microstructure models which are widely used for determining effective transverse elastic properties of unidirectional fiber reinforced composites. The first model based on the classic mechanics of materials permits free unloaded opposite boundaries in the unite cell, while the second one introduces straight-edge constraints in the unite cell to represent interactions of neighboring cells during deformation. The two approaches are firstly verified by the periodic circular hole problems. Then three microstructures are taken into consideration including the circular fibers, square fibers, and circular fiber clusters periodically embedded in the matrix and solved by finite element analysis. A comparison of the numerical results demonstrates that the two computational models with and without periodic conditions can give different predictions on the effective elastic properties of composite for both low and high fiber volume fractions, especially for the effective Poisson’s ratio of composite. Applying periodic straight-edge constraints after deformation can prevent any over-constrained conditions in the numerical model and give more stable results.
https://www.ije.ir/article_73285_05ce17000cd86904b5b0815940041cfe.pdf
Fiber
reinforced composite
effective transverse elastic properties
free boundary
straight
edge boundary
Finite Element
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1505
1513
73286
Effects of Far- and Near-Field Multiple Earthquakes on the RC SDOF Fragility Curves Using Different First Shock Scaling Methods
P Kamrani Moghaddam
p.kamrani@urmia.ac.ir
1
A. R. Manafpour
a.manafpour@urmia.ac.ir
2
Civil Engineering Department, Urmia University, Urmia, Iran
Civil Engineering Department, Urmia University, Urmia, Iran
Typically, to study the effects of consecutive earthquakes, it is necessary to consider definite intensity levels of the first shock. Methods commonly used to define intensity involve scaling the first shock to a specified maximum interstorey drift. In this study the structure’s predefined elastic spectral acceleration caused by the first shock is also considered for scaling. This study aims to investigate the effects of consecutive far-field (FF) and near-field (NF) ground motions on the exceedance probability of different performance levels of a reinforced concrete single degree of freedom system considering the aforementioned first shock scaling methods. Eight groups of simulations are defined with each considering a combination of FF and NF ground motions. By using elastic spectral acceleration as the scaling method, it is found that the exceedance probability of the second shock performance levels, especially in pulse-like records, greatly depends on the order of far/near field ground motions and the level of damage caused by the first shock. It could be inferred that although first shock scaling method to maximum drift ratio is the commonly used method, the effects of record type multiple earthquakes are more revealed using elastic spectral acceleration as the first shock scaling criteria.
https://www.ije.ir/article_73286_ce189c860b63540670713adbf4de0471.pdf
First shock intensity Scaling
Consecutive Earthquakes
Fragility curves
FAR
and Near
Field Ground Motions
Pulse Effects
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1514
1520
73287
Modification of the Properties of Warm Mix Asphalt Using Recycled Plastic Bottles
A. M. Mosa
ahmed.mancy@muc.edu.iq
1
I. T. Jawad
engibtehaj.taha@uobabylon.edu.iq
2
L. A. Salem
lubna.abdulrahman@muc.edu.iq
3
Civil Engineering Department, AL Mansour University College, Baghdad, Iraq
Department of Civil Engineering, College of Engineering, University of Babylon, Hilla, Iraq
Civil Engineering Department, AL Mansour University College, Baghdad, Iraq
Construction of flexible pavements with hot mix asphalt (HMA) mixtures consumes huge energy which impacts the resources and the environment of the world. Warm Mix Asphalt (WMA) is an effective alternative as they produced with lower mixing and compaction temperature than those used in HMA production. This technology decreases energy consumption, saves money, and reducing the environmental pollution. This technology, if combined with the use of waste materials to improve the properties of WMA, can generate a revolution in sustainable construction. Polyethylene Therephthalate (PET) wastes accumulated over the world increasingly. However, and to the best knowledge of the author, no such research adopts using PET wastes in combination with WMA properties improvement. Therefore, this study covers usage of PET waste bottles to modify the properties of WMA. The study adopted usage of ground PET waste bottles with maximum particle size of 2.36 mm with different contents (0.1%, 0.3%, 0.5%, 0.7%, 0.9%, and 1.1% by the weight of aggregate) to replace an equivalent portion of fine aggregate. The study involved a number of laboratory tests to investigate the effects of different PET content on the properties of WMA. The testing program included Marshall tests and rutting susceptibility tests. The results exhibited significant improvement in engineering properties of the mixtures modified with optimum PET content (which was found to be 0.5%) in terms of increase in stability and stiffness and decrease in rutting susceptibility without adverse effects on the other desirable properties of the mixture.
https://www.ije.ir/article_73287_45ba382848dde5441e4dc2b6b30a18f8.pdf
PET Waste
Marshall Properties
Rutting Susceptibility
WMA
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1521
1528
73288
Analysis and Development of Technology Acceptance Model in Mobile Bank Field
D Moazenzadeh
moazenzadeh.del@yahoo.com
1
H. Hamidi
h_hamidi@kntu.ac.ir
2
Department of Information Technology Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran.
Department of Industrial Engineering, Information Technology Group, K. N. Toosi University of Technology, Tehran, Iran.
Internet-based banking (Internet bank) has limitations such as access to the Internet Network and PC (Personal Computer) in addition to providing bank services at any time and easily to customers. The provision of mobile phone services with the title of Mobile Bank was introduced to eliminate these restrictions and limitations. Due to the importance of technology adoption by users, in this research, the technology acceptance model has been developed by taking into account the variables of the original model, by adding new variables such as risk perception, cost perception, trust, resistance, compatibility while examining the proposed models to examine these factors. This research has analyzed the statistical population using the questionnaire and has determined the following results. Individual's age has not much effect on the technology adoption according to results, and also individuals do not have much resistance to adopt the technology in this period, which will cause to adopt new technologies more and more. Individuals are also willing to pay for the use of technology and benefiting from its advantages, and cost has not affected the attitude of individuals and is not an impediment and barrier to technology adoption, and ultimately, individuals have adopted the risk of the use of technology, and this issue does not damage their trust in new technology.
https://www.ije.ir/article_73288_0c3117adf26951898de26c018856dc77.pdf
Adoption of Mobile Bank
Mobile Bank
Development of Technology Acceptance Model
banking
Fuzzy TOPSIS
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1529
1535
73289
Voice-based Age and Gender Recognition using Training Generative Sparse Model
S. Mavaddati
s.mavaddati@umz.ac.ir
1
Department of Engineering and Technology, University of Mazandaran, Babolsar, Iran
Abstract: Gender recognition and age detection are important problems in telephone speech processing to investigate the identity of an individual using voice characteristics. In this paper a new gender and age recognition system is introduced based on generative incoherent models learned using sparse non-negative matrix factorization and atom correction post-processing method. Similar to general signal classification scheme, our proposed algorithm includes train step to provide related atoms to each signal class and test phase to assess classification performance. Since the classification accuracy depends highly on the selected features, we employ Mel-frequency cepstral coefficients to train basis for better representation of speech structure. These bases are learned over data of male and female speakers using non-negative matrix factorization with sparsity constraint. Then, atom correction is carried out using an energy-based algorithm to decrease coherence between different categories of trained dictionaries. In sparse representation of each data class, atoms related to other sets with the highest energy are replaced with the lowest energy bases if reconstruction error does not exceed from a specified limit. The experimental results show that the proposed algorithm performs better than the earlier methods in this context especially in the presence of background noise.
https://www.ije.ir/article_73289_c2e5f510617f3ef6a6a325f1582f0843.pdf
Gender recognition
Sparse Non
negative matrix factorization
Incoherence
Mel
frequency cepstral coefficient
Voice processing
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1536
1545
73290
Sensorless Model Predictive Force Control with a Novel Weight Coefficients for 3-Phase 4-Switch Inverter Fed Linear Induction Motor Drives
S. Masomi Kazraji
masomi_saeed@yahoo.com
1
M. R. Feyzi
feyzi@tabrizu.ac.ir
2
M. B. B. Sharifin
sharifian@tabrizu.ac.ir
3
S. Tohidi
tohidi@tabrizu.ac.ir
4
Faculty of Electrical & Computer Engineering, University of Tabriz, Iran
Faculty of Electrical and Computer Engineering University of Tabriz, Tabriz, Iran
Faculty of Electrical and Computer Engineering University of Tabriz, Tabriz, Iran
Faculty of Electrical and Computer Engineering University of Tabriz, Tabriz, Iran
The sensorless model predictive force control (SMPFC) is a strong method for controlling the drives of three-phase 4(6)-switch inverter linear induction motors. This kind of inverter can be employed for fault tolerant control in order to solve the problem of open/short circuit in 6-switch inverters (B6). This paper proposed a method for the SMPFC of a linear induction motor (LIM) with a 4-switch inverter fed along with DC-link voltage offset suppression. Numerical simulations have been performed on several different LIMs in MATLAB software for determine the weight coefficients of the stator flux and the reduced of the capacitor voltage offset. Then, a relationship has been extracted for determining the weight coefficients of the stator flux and DC-link voltage in the cost function of the SMPFC. Using weight coefficients in the cost function, the B4 inverter voltage vectors under the DC-link capacitor voltage swing were obtained for the exact prediction. The balance among the currents was improved by determining the appropriate value for the weight coefficient of the reduced of the capacitor voltage offset. Simulation results were provided for the validation of the suggested control method.
https://www.ije.ir/article_73290_8b80ae0609abbf0d9239370b90546722.pdf
Linear Induction Motor (LIM)
Sensorless Model Predictive Force Control (SMPFC)
4
switch inverter
Weight Coefficient
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1546
1552
73291
Low Dropout Based Noise Minimization of Active Mode Power Gated Circuit
D. Nath
nath.debanjali@gmail.com
1
S. N. Pradhan
sambhu.pradhan@gmail.com
2
Department of Electronics & Communication Engineering, National Institute of Technology Agartala, Agartala, India
Department of Electronics & Communication Engineering, National Institute of Technology Agartala, Agartala, India
Power gating technique reduces leakage power in the circuit. However, power gating leads to large voltage fluctuation on the power rail during power gating mode to active mode due to the package inductance in the Printed Circuit Board. This voltage fluctuation may cause unwanted transitions in neighboring circuits. In this work, a power gating architecture is developed for minimizing power in active mode and noise is analyzed. The effect of different noise minimization approaches for reducing power supply noise is evaluated in power gating architecture. A new concept of noise minimization technique using Low Dropout Voltage regulator is proposed in this paper. The amount of charge in the internal nodes of the power gating circuit passes through the sleep transistors during the wake-up transition is controlled by the proposed noise minimization techniques. The Low Dropout Voltage Regulator is designed newly in such a way that can be used to reduce bounce noise by minimizing voltage fluctuation on the power rail of power gating circuit. Architectures have been developed in Synopsys Custom Designer tool at iPDK 90nm technology. Percentage saving of noise on the power supply is reduced up to 99%.
https://www.ije.ir/article_73291_2c7659bbf892d42f6d1f8047a494e26f.pdf
architecture powergating data
retention leakage noise low
dropout voltage
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1553
1558
73292
A High Gain and Forward Body Biastwo-stage Ultra-wideband Low Noise Amplifier with Inductive Feedback in 180 nm CMOS Process
S. S. Mousavi
saeid.mosavi1368@gmail.com
1
J. Ghasemi
j.ghasemi@umz.ac.ir
2
M. Gholami
m.gholami@umz.ac.ir
3
Mazandaran University of Sience and Technology, Babol, Iran
University of Mazandaran, Babolsar, Iran
University of Mazandaran, Babolsar, Iran
This paper presents a two-stage low-noise ultra-wideband amplifier to obtain high and smooth gain in 180nm CMOS Technology. The proposed structure has two common source stages with inductive feedback. First stage is designed about 3GHz frequency and second stage is designed about 8GHz. In simulation, symmetric inductors of TSMC 0.18um CMOS technology in ADS software is used.Simulations results show high and relatively smooth S21 equal to 18.674±1.38dB, noise figure of less than 3.7dB, power consumption of 14.6mW with 1.2v supply voltage and suitable matching at the input (S11
https://www.ije.ir/article_73292_261f88c34ca9fba5812b677964672a11.pdf
Low Noise Amplifier
UWB
Inductive feedback
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1559
1567
73293
Optimal Control of the Vehicle Path Following by Using Image Processing Approach
Y. Pourasad
faroughi.alireza.h@gmail.com
1
Faculty of Electrical Engineering, Urmia university of Technology, Urmia, Iran
Nowadays, the importance of the vehicles and its dramatic effects on human life is no secret. The use of trailers with multiple axels for transporting bulky and heavy equipment is essential. Increase in trailers axles which results increment of wheels, needs considerations in order to increase in transporting speed, maneuverability, safety, better control and path following accurately. Therefore, in this paper dynamic modeling and control of a 5 axial trailer was studied. As well as to increase maneuverability and speed up, steering 3 axles was considered. Also, by using image processing trailer path following in desired path with the highest accuracy was achieved. In this study, first a 14 DoF model for a 5 axial trailer with 3 steering axles was considered and its characteristics were described. Then, dynamic equations including kinematic and kinetic of trailer was obtained. Then, with checking trailers behavior a linear quadratic optimal control algorithm was designed. To evaluate the performance of the control algorithm, control problem simulation for 3 maneuver; single lane change, double lane change and overtaking; was done. The results confirmed the performance of designed control algorithm and image processing accuracy in trailer path following.
https://www.ije.ir/article_73293_4ada96e0fed758b738a665732dd2c011.pdf
Trailer
image processing
Path Following
Optimal control
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1568
1574
73294
Considering Production Planning in the Multi-period Inventory Routing Problem with Transshipment between Retailers
A. Roostaei
a.roostaei@modares.ac.ir
1
I. Nakhai Kamal Abadi
nakhai.isa@gmail.com
2
Department of Industrial Engineering, Tarbiat Modares University, Tehran, Iran
Department of Industrial Engineering, University of Kurdistan, Sanandaj, Iran
Generally, the inventory routing problem occurs in a supply chain where customers consider the supplier responsible for inventory replenishment. In this situation, the supplier finds the answer to questions regarding the time and quantity of delivery to the customer as well as the sequence of customers in the routes. Considering the effect of production decisions on answering these questions, the present paper examines the integrated decision making on production, routing and inventory in a two-echelon supply chain composed of a manufacturer and multiple retailers. Transshipment, as a policy in supply chain logistic which increase integration and decrease inventory cost, is also allowed between retailers. The mathematical formulation for the problem is developed and an adaptive large neighborhood search heuristic is proposed to solve this complicated problem. The results of numerical experiments show that the solutions yielded by the heuristic method have high efficiency.
https://www.ije.ir/article_73294_56d823c2a4725045279477cd326ca693.pdf
Inventory routing
Production Planning
Transshipment between retailers
Adaptive large neighborhood search
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1575
1584
73295
A possibilistic bi-objective model for a competitive supply chain network design under variable coverage
A. Shamekhi Amiri
ashamekhi@ut.ac.ir
1
S. Ali Torabi
satorabi@ut.ac.ir
2
R. Ghodsi
ghodsi@ut.ac.ir
3
School of Industrial Engineering, College of Engineering, University of Tehran, Tehran, Iran
School of Industrial Engineering, College of Engineering, University of Tehran, Tehran, Iran
Central Connecticut State University, Connecticut, USA
In this paper, the strategic planning of a supply chain under a static chain-to-chain competition on the plane is addressed. It is assumed that each retailer has a coverage area called the radius of influence. The demand of each demand zone is divided equally between the retailers which can cover that market. However, the demand of distant customers who are not in the retailers’ radius of influence, will be lost. This competition is modelled for a real case application of a super market chain. It is assumed that the chain’s owner wants to expand retail outlets to improve its market share. Since this expansion could affect the current customers of existing retailers, the owner wants to avoid attacking the market share of its current retailers. A bi-objective fuzzy mixed integer nonlinear model is proposed. For solving the model, it is first reformulated to a mixed integer linear program and then an interactive approach is devised to handle the fuzzy bi-objective model. Four expansion strategies are analysed from which useful managerial insights are drawn.
https://www.ije.ir/article_73295_b2d078eb39a9e2553712432252d24257.pdf
Facility location on the plane
Chain
to
chain competition
Radius of influence
Cannibalization effect
capacity planning
multi
objective possibilistic programming
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1585
1592
73296
Investigation of the Size Effect on the Nano-beam Type Piezoelectric Low Power Energy Harvesting
Z. Tadi Beni
zahra.tadi@gmail.com
1
S. A. Hosseini Ravandi
hoseinir@cc.iut.ac.ir
2
Y. Tadi Beni
tadi@sku.ac.ir
3
Department of Textile Engineering, Isfahan University of Technology, Isfahan, Iran
Department of Textile Engineering, Isfahan University of Technology, Isfahan, Iran
Department of Mechanical Engineering, Shahrekord University, Shahrekord, Iran
In this paper, size dependent beam type peizoelectric energy hardvester is investigated. For this goal, first nonlinear formulation of isotropic piezoelectric Euler-Bernoulli nano-beam is developed based on the size-dependent piezoelectricity theory then special beam type piezoelectric energy hardvester is probed for different parameters. Basic nonlinear equations of piezoelectric nano-beam are derived using principle of minimum of potential energy and variational method. To evaluate the formulation derived, static deformation and free vibration of the clamped-clamped piezoelectric nano-beam is investigated in the special case. The results of the formulation derived are investigated under different parameters, and particularly, the ability and performance of the beam type piezoelectric low power energy harvesting was evaluated in nanoscale.
https://www.ije.ir/article_73296_e793807d1630ae5e49a7303327e3f85c.pdf
Piezoelectric
size effect
Euler
Bernoulli nano
Beam
Energy harvesting
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1593
1601
73297
Autonomous Underwater Vehicle Hull Geometry Optimization Using a Multi-objective Algorithm Approach
S. Abbasi
s_abbasi@arakut.ac.ir
1
M. Zeinali
zeinali@alumni.iust.ac.ir
2
P. Nejadabbasi
nejadabbasi@mecheng.iust.ac.ir
3
School of Mechanical Engineering, Arak University of Technology, Arak, Iran
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
Abstarct In this paper, a new approach to optimize an Autonomous Underwater Vehicle (AUV) hull geometry is presented. Using this methode, the nose and tail of an underwater vehicle are designed, such that their length constraints due to the arrangement of different components in the AUV body are properly addressed. In the current study, an optimal design for the body profile of a torpedo-shaped AUV is conducted, and a multi-objective optimization scheme based on the optimization algorithm NSGA-II (Non-dominated Sorting Genetic Algorithm-II, as an evolutionary algorithm) is employed. In addition, predefined geometrical constraints are considered so that equipment with the specific dimensions can be placed inside the AUV space without any effect on the AUV volume and the wetted surface. By optimizing the parameters of the newly presented profile, in addition to maximizing the volume and minimizing the wetted surface area, more diversed shapes can be achieved than with the ‘Myring’ profile. A CFD analysis of the final optimal design indicates that with the help of the proposed profile, the hydrodynamic parameters for the AUV hull are improved effectively.
https://www.ije.ir/article_73297_fa6cce3af96e86b7aec6dfcabacbfdd7.pdf
Autonomous underwater vehicles
Hull shape design
multi
objective optimization
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2018-09-01
31
9
1602
1608
73298
Investigating the Effects of Cold Bulge Forming Speed on Thickness Variation and Mechanical Properties of Aluminum Alloys: Experimental and Numerical
S. M. R Tabatabaei
mitso64sed@yahoo.com
1
K. Alasvand Zarasvand
alasvand@stu.sku.ac.ir
2
Department of Mechanical Engineering, Razi University of Kermanshah, Kermanshah, Iran
Department of Mechanical Engineering, Shahrekord University, Shahrekord, Iran
In this work, cold bulge forming of an Aluminium-Magnesium (Al-Mg) sheet with a solid bulging medium is performed experimentally and numerically. Mechanical properties and thickness variations of Al-Mg sheet are evaluated before and after the forming process. The results indicated that the Al-Mg sheet has taken the desired shape without necking using the cold bulge forming process. Also, the experimental results show significant improvements in mechanical properties of Al-Mg sheet after bulge forming. It is proved that the maximum thickness reduction of Al-Mg blank is less than 6% after cold bulge forming. Numerical simulations of cold bulge forming of Al-Mg sheet are conducted using Abaqus finite element software. For this purpose, many numerical models are created and analysed to investigate the effects of bulge forming speed on the blank thickness variation for different Aluminium alloys. In these simulations, four different speed of 1, 5, 15 and 25mm/min are used as forming speeds. Numerical results of bulge forming of Al-Mg sheet are compared with experimental measurements and good correlation is observed between the results. Moreover, obtained results from numerical simulations for different Aluminium alloys show that the thickness variations of formed Al-Mg sheet are more uniform by reducing the forming speed.
https://www.ije.ir/article_73298_d3218ee5617c83acbdf1425fddecfb99.pdf
Cold bulge forming
Al
Mg sheet
Thickness variations
Numerical
experimental