Fluidization of Initialty Segregased Equidensity Binary System
E. N.
Wami
Chemical & Petroleum Engineering, Rivers State University of Science and Technology
author
text
article
1996
eng
Fluidization of initially segregated binary mixtures has been investigated for particle systems of the same material. This paper reports experiments conducted in 0.055m diameter fluidizes bed for binary mixtures composed of sands whose sizes ranged from 450 to 1450mm. An empirical relationship, Utf = 0.95 UF (dR)0.87, was derived in terms of the minimum fluidization of the smaller particle, UF , and particle diameter ratio, dR , for predicting the velocity at commencement of total fluidization. This expression was found also suitable for estimating the take-over velocity or equidensity binary systems which enables good prediction of mixing behaviour. The corresponding exprrision for pressures drop at the commencement of total fluidization was = exp(1.7 UF(dR)0.13)
International Journal of Engineering
Materials and Energy Research Center
1025-2495
9
v.
2
no.
1996
1
7
https://www.ije.ir/article_71146_5cdb7c5d350b6b0e002593488a6e6a6d.pdf
Simulation of a Variable Reluctance Steping Motor for Sinusoidal and Step Exitations
R.
Iranpour
Electerical Engineering, University of Tabriz
author
Jawad.
Faiz
Electrical and Computer Engineering, University of Tehran
author
text
article
1996
eng
Steady-state dynamic simulation of a variable reluctance stepping motor is carried out by applying two different excitation voltages. First a single-step voltage is applied to the motor, and a sinusoidal voltage, as the first term of Fourier series of the single-step voltage, is then used as the input voltage of the motor. In both cases plots of machine torque, current and speed are presented. A comparison between the results of the two cases shows that a sinusoidal input voltage cannot predict the real performance of the motor, and in critical dynamic conditions, a single-step response is far from the reality. Reasons for these discrepancies arising from the various factors are discussed in the paper.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
9
v.
2
no.
1996
9
20
https://www.ije.ir/article_71147_6dccf18a23e9807daee5a16e6ae33b5d.pdf
Economic and Effectiveness Evaluation Analysis of Some Resource Allocation Procedures
S.M.
Seyed- Hosseini
Industrial Engineering, Iran University of Science & Technology
author
text
article
1996
eng
Review of theoretical models for cost-effectiveness and of procedures currently being used by different levels of decision makers to evaluate the projects or alternatives is the main objective of this article. To come to some conclusion that which theoretical model would be more effective to be applied for allocating the limited resources among different projects. the performance evaluation procedure has been developed. Some of the popular and commonly used models such as B/C analysis and its various improved versions. Integer Programming has been developed and critically analyzed and the suitable procedure under different levels of project funding strategy is recommended.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
9
v.
2
no.
1996
21
28
https://www.ije.ir/article_71148_7038aae85c8cb5b269f01d6dac773fb0.pdf
Freezing in a Finite Slab Using Extensive Perturbation Expansions Method
A.
Baradaran Rahimi
Mechanical Engineering, Ferdowsi University of Mashhad
author
text
article
1996
eng
In this paper Mathematica is used to solve the moving boundary problem of freezing in a finite slab for higher order perturbations. Mathematica is a new system which makes it possible to do algebra with computer. More specifically, it enables researchers to find the location of the ice at any time for as high order of perturbation as one whishes. Using of Mathematica and outer solution and an inner solution for the quantities involved are developed and then these solutions are matched together using the method of matched asymptotic expansions. At the end the composite solutions are compared to the available low-order solutions.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
9
v.
2
no.
1996
29
35
https://www.ije.ir/article_71149_9a291fffa4196fb45519a7c57aa038fd.pdf
Fiber - Optic Sensing of Linear Thermal Expansion (RESEARCH NOTES)
H.
Golnabi
Water & Energy, Sharif University of Technology
author
text
article
1996
eng
The use of a LED fiber-optic sensor to measure displacement and linear thermal expansion is described. It has a sensitivity of about 0.6 mV/mm, a resolution of 1.25 mm, and a dynamic rang of 400 mm for displacement measurements. For thermal expansion, it shows a sensitivity of about 3.5 mV/C, and the experimental linear expansion values are in agreement with those calculated. The reported sensor offers the advantage of simplicity, reliability, high sensitivity, and a wide dynamic range with a minimum cost.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
9
v.
2
no.
1996
37
43
https://www.ije.ir/article_71150_d41d8cd98f00b204e9800998ecf8427e.pdf
Thermal -Hidraolyc Study of Trr Core in Fuel Conversion Frome Highly Enriched Uranium to Low Enriched Uranium Fuel (RESEARCH NOTES)
M.A.
Shirazi
Physics, Sharif University of Technology
author
text
article
1996
eng
International Journal of Engineering
Materials and Energy Research Center
1025-2495
9
v.
2
no.
1996
45
52
https://www.ije.ir/article_71151_b08fecb45261d248df8ef46ef4622e37.pdf
Turbine Blade Investment Casting Cost Estimating Model (TECHNICAL NOTES)
Mohammad
Saidi Mehrabad
Industral Engineer, Iran University of science and technology
author
text
article
1996
eng
The objective of this research is to develop a turbine blade investment casting cost advisor model to assist a blade designer in decision-making in a concurrent engineering environment. It is a microcomputer based cost estimating system that employs a manufacturing knowledge base. The concept of the manufacturing process for blade production by the investment casting method is used to develop the model, which is suitable for implementation in the concurrent engineering environment. The program will aid the blade designer in examining the design with respect to manufacturing cost. This approach considers the feasibility of manufacturing design at the early design stage to reduce the manufacturing and engineering costs. The system was tested during at trial run. The results indicate that this model could provide a substantial improvement in production cost.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
9
v.
2
no.
1996
53
59
https://www.ije.ir/article_71152_d41d8cd98f00b204e9800998ecf8427e.pdf