ORIGINAL_ARTICLE
Optimal Sliding-Mode Guidance Law for Fixed-Interval Propulsive Maneuvers
An optimal strategy based on minimum effort control and also with terminal positionconstraint is developed for an exoatmospheric interceptor with a fixed- interval guidance time. It isthen integrated with sliding-mode control theory to drive an optimal sliding-mode guidance law forfixed-interval guidance time. In addition, this guidance law is generalized for intercepting anarbitrarily time-varying target maneuver. Robustness of the new guidance method againstdisturbances and good miss distance performance are achieved by the second method of Lyapunovand simulation results. The presented guidance law is simple to implement in practical applications.
http://www.ije.ir/article_71696_6cd4e74aafb20a4f9d2f4147d28b5c0e.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
105
112
optimal
Sliding
mode
guidance
robust
Fixed
Interval
B.
Ebrahimi
becrd@aut.ac.ir
true
1
Mechanical Engineering, Amirkabir University of Technology
Mechanical Engineering, Amirkabir University of Technology
Mechanical Engineering, Amirkabir University of Technology
AUTHOR
M.
Bahrami
mbahrami@aut.ac.ir
true
2
Mechanical Engineering, Amirkabir University of Technology
Mechanical Engineering, Amirkabir University of Technology
Mechanical Engineering, Amirkabir University of Technology
AUTHOR
J.
Roshanian
roshanian@kntu.ac.ir
true
3
aerospace engineering, K. N. Toosi university of technology
aerospace engineering, K. N. Toosi university of technology
aerospace engineering, K. N. Toosi university of technology
AUTHOR
ORIGINAL_ARTICLE
Pool Boiling Heat Transfer in Water/Amines Solutions
In this investigation, nucleate boiling heat transfer coefficients were experimentally measured during pool boiling of mixtures, consisting of water/monoethanolamine and water/diethanolamine on a horizontal heating rod, under atmospheric pressure. The experiment was carried out below 205 kW.m-2 heat flux, over a wide range of concentrations. These experiments include, measurement of pool boiling heat transfer coefficient and also visual information. Applicability of the existing main correlations is briefly discussed, with the present experimental data. The major predictions(over and/or under) were observed in some parameter range by the existing correlations. In this investigation the correlations of Fujita et al and Inoue et al, which are structurally the same but have different tuning parameters were modified for this system and the average error has been significantly reduced.
http://www.ije.ir/article_71698_c32a5a38a69907c0b264df341a367e8a.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
113
131
Pool Boiling
Heat Transfer Coefficient
Amine Solutions
Correlations
M.
Jamialahmadi
jamialahmadi@yahoo.com
true
1
Petroleum Engineering, University of Petroleum Industry
Petroleum Engineering, University of Petroleum Industry
Petroleum Engineering, University of Petroleum Industry
AUTHOR
A. A.
Safekordi
safekordi@sharif.edu
true
2
Chemical & Physic Emgineering, Sharif University of Technology
Chemical & Physic Emgineering, Sharif University of Technology
Chemical & Physic Emgineering, Sharif University of Technology
AUTHOR
S. A.
Alavi Fazel
alavifazel@gmail.com
true
3
Mahshahr Branch, Islamic Azad University
Mahshahr Branch, Islamic Azad University
Mahshahr Branch, Islamic Azad University
AUTHOR
ORIGINAL_ARTICLE
A Newly Developed Laboratory Slab Roller Compactor (Turamesin): An Overview
Methods of preparing test specimens in laboratories are particularly important. It also holds true in terms of compaction procedure in predicting pavement performance. The currently available laboratory compactor cannot adequately replicate field compaction conditions, especially the Stone Mastic Asphalt (SMA) mixture. The essential element of SMA mixture comprises of stones that are placed next to or on top of each other, and therefore are greatly affected by the compaction procedure. Conclusion of different studies have indicated that rolling wheel compactor, simulates properties that are closer to field compaction. Turamesin was developed as an improved method oflaboratory slab roller compactor, to provide a solution for the problem of producing laboratoryspecimens, which would represent materials laid and compacted in the field. This paper gives anoverview of Turamesin and discusses the findings of the units' first phase Pilot Study, conducted inorder to provide specific information, to improve procedures for slab preparation and compaction,also determining the criteria for slab compaction and performance of Turamesin. Turamesin is able tocompact, a slab area measuring; 600 mm by 500 mm, according to clients' specified thicknesses, withnumber of passes up to 75, within 15 minutes time period. One compacted slab could produce up to16 cylindrical core specimens of 100 mm diameter. Turamesin has shown great potential to beadopted as standard laboratory slab compactor, for asphalt mixtures and seemes to be capable ofsimulating field compaction in terms of operational procedures. However, improvement of theTuramesin will need significant amount of research to develop and finalize the optimum procedures.
http://www.ije.ir/article_71701_b305a426be19df392f87af7d5a68c841.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
133
142
Roller Compactor
slab
Asphalt mixtures
Laboratory Compaction
Field Simulation
A. R.
Mahmud
arm@eng.upm.edu.my
true
1
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
AUTHOR
S.
Hassim
hsalih@eng.upm.edu.my
true
2
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
AUTHOR
F. M.
Jakarni
fauzan@eng.upm.edu.my
true
3
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
AUTHOR
R.
Muniandy
ratnas@eng.upm.edu.my
true
4
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
Civil Engineering, Universiti Putra Malaysia
AUTHOR
ORIGINAL_ARTICLE
Finite Horizon Economic Lot and Delivery Scheduling Problem: Flexible Flow Lines with Unrelated Parallel Machines and Sequence Dependent Setups
This paper considers the economic lot and delivery scheduling problem in a two-echelon supply chains, where a single supplier produces multiple components on a flexible flow line (FFL) and delivers them directly to an assembly facility (AF). The objective is to determine a cyclic schedule that minimizes the sum of transportation, setup and inventory holding costs per unit time without shortage. We have developed a new mixed zero-one nonlinear mathematical model for theproblem. Due to the difficulty of obtaining the optimal solution, especially in the instances of medium and large-sized problems, two meta-heuristic algorithms (HGA and SA) are proposed and evaluatedover randomly generated problems. Computational results indicate that the proposed HGA outperforms the SA algorithm with respect to both the solution quality and computation times especially in large-size problems.
http://www.ije.ir/article_71703_69573c3fb9b08b8d2be8bcc1b478a9ce.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
143
158
Flexible Flow Lines
Lot and Delivery
scheduling
Unrelated Parallel Machines
Finite planning horizon
Hybrid genetic algorithm
Simulated Annealing
S. A.
Torabi
satorabi@ut.ac.ir
true
1
School of Industrial Engineering, University of Tehran
School of Industrial Engineering, University of Tehran
School of Industrial Engineering, University of Tehran
AUTHOR
S. M. T.
Fatemi Ghomi
fatemi@aut.ac.ir
true
2
Industrial Engineering, Amirkabir University of Technology
Industrial Engineering, Amirkabir University of Technology
Industrial Engineering, Amirkabir University of Technology
AUTHOR
M.
Jenabi
m_jenabi@aut.ac.ir
true
3
Industrial Engineering, Amirkabir University of Technology
Industrial Engineering, Amirkabir University of Technology
Industrial Engineering, Amirkabir University of Technology
AUTHOR
ORIGINAL_ARTICLE
A New Multi-Objective Model for Dynamic Cell Formation Problem with Fuzzy Parameters
This paper proposes a comprehensive, multi-objective, mixed-integer, nonlinear programming (MINLP) model for a cell formation problem (CFP) under fuzzy and dynamic conditions aiming at: (1) minimizing the total cost which consists of the costs of intercellular movements and subcontracting parts as well as the cost of purchasing, operation, maintenance and reconfiguration of machines, (2) maximizing the preference level of the decision making (DM) and (3) balancing intracellular workload. Dynamic CFP divides the planning horizon to smaller periods and considers different product combinations and demands in each period, which may result in cell reconfiguration necessity. Moreover, it is more realistic to take into account the inexact and uncertain (fuzzy) nature of parameters, such as product demand or machine capacity. The main goals of the proposed model is to select a process plan with the minimum cost and also to identify the most appropriate production volume with respect to fuzzy demands and capacities in order to minimize the deviation from the desired production and balanced machine workload.
http://www.ije.ir/article_71706_fece29c368630c6d8f24134af56abf7d.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
159
172
multi
Objective Cell Formation Problem
Dynamic CMS
Fuzzy theory
S.
Minaeian
sminaeian@gmail.com
true
1
Industrial Engineering, Sharif University of Technology
Industrial Engineering, Sharif University of Technology
Industrial Engineering, Sharif University of Technology
AUTHOR
Reza
Tavakkoli-Moghaddam
tavakoli@ut.ac.ir
true
2
Industrial Engineering, University of Tehran
Industrial Engineering, University of Tehran
Industrial Engineering, University of Tehran
AUTHOR
Masoud
Rabbani
mrabani@ut.ac.ir
true
3
Industerial Engineering, professor
Industerial Engineering, professor
Industerial Engineering, professor
AUTHOR
ORIGINAL_ARTICLE
Magnetic Studies of Fine Fe And Co Species Formed in Fe/Zeolite Catalysts
Magnetic, Mössbauer, and I.R. studies of nanosize particles of Fe and Co species dispersed in a cage of aluminosilicates structure, in relation to syngas (CO+H2) Fischer Tropsch conversion. The difference in the catalytic activity of such species have shown dependancy on their degree of dispersion. The carbonyl impregnation gave ultra-fine Super Paramagnetic Fe3O4, whereas the nitrate impregnation gave larger size particles of Fe3O4 or α-Fe2O3. The active Fe5C2 component was converted to Fe3C during the above reaction.
http://www.ije.ir/article_71709_716e2ec2f2b945dca4cac05ca9c6d1c5.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
173
180
Nanosize
Super Paramagnetic
Fine Particles
Mossbauer
Mohammad Mahdi
Oskoie
oskoie@sharif.edu
true
1
Water & Energy, Sharif University of Technology
Water & Energy, Sharif University of Technology
Water & Energy, Sharif University of Technology
AUTHOR
ORIGINAL_ARTICLE
Second Law Based Analysis of Fluid Flow in the Regenerator of Pulse Tube Refrigerators
As a necessary component, regenerator plays an important role in the refrigeration performance of the pulse tube refrigerator. The objective of this research is to investigate the flow characteristics in a porous regenerator of the pulse tube refrigerators, subjected to oscillating flow. The hydrodynamic and thermal behavior of the regenerator is investigated by considering porous media approach. The conservation equations are transformed by implementing the volumetric average scheme. Harmonic approximation technique is employed to derive an analytical solution. To investigate the system performance, second law analysis is performed in order to calculate the second law efficiency. The effect of geometry and operating key parameters on the regenerator performance are investigated as well. The developed model is able to predict the oscillating flow characteristics in the regenerator.
http://www.ije.ir/article_71711_ae95f71881d7df0dcfb1583c194b6fc3.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
181
194
Oscillatory Flow
Porous media
Entropy generation
Regenerator
S.
Kazemzadeh Hannani
hannani@sina.sharif.ac.ir
true
1
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
AUTHOR
M.H.
Saidi
saman@sharif.edu
true
2
Mechanical Engineering, Center of Excellence in Energy Conversion,Sharif
Mechanical Engineering, Center of Excellence in Energy Conversion,Sharif
Mechanical Engineering, Center of Excellence in Energy Conversion,Sharif
AUTHOR
A.
Jafarian
jafarian@yahoo.com
true
3
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
AUTHOR
ORIGINAL_ARTICLE
A “v2-f Based” Macroscopic K-Ε Model for Turbulent Flow through Porous Media
In this paper a new macroscopic k-ε model is developed and validated for turbulent flow through porous media for a wide range of porosities. The morphology of porous media is simulated by a periodic array of square cylinders. In the first step, calculations based on microscopic v2 − f model are conducted using a Galerkin/Least-Squares finite element formulation, employing equalorder bilinear velocity-pressure elements. Calculations are validated by comparing the results to available data in the literature. In the second step, the volume averaged properties are extracted fromthe microscopic solution of v2 − f model. Then, employing the volume average technique, the macroscopic transport equations of continuity, momentum and k-ε model are derived and modeled. Inthe third step and during the volume averaging process, additional terms appeared in the k-ε model are interpreted and compared with the volume averaged properties that are extracted from the solutionof microscopic v2 − f model. Finally a “ v2 − f based” macroscopic k-ε model is developed and validated successfully for a wide range of porosities by comparing the macroscopic data to those predicted by microscopic v2 − f model. Moreover, the results of the calculations are compared with the result of an experimental work in the literature in order to validate the accuracy of the model.
http://www.ije.ir/article_71713_6494dea6d3bc7e1767f2d280086f9f86.pdf
2008-06-01T11:23:20
2020-05-28T11:23:20
195
212
Porous
Turbulence
K
ε
v2 − f
R.
Bahoosh-Kazerooni
bahoosh@mehr.sharif.edu
true
1
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
AUTHOR
S.
Kazemzadeh Hannani
hannani@sina.sharif.ac.ir
true
2
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
Mechanical Engineering, Sharif University of Technology
AUTHOR