The Potentiodynamic Behavior of Copper in NaCI Solutions Studied by Auger and Photoelectron Spectroscopy
J.
Avanessian
, Merc
author
text
article
1988
eng
The potentiodynamic behaviour of copper in brine solutions was studies. Auger and photo-electron spectroscopy were used together with electrochemical methods. It is demostrated that the passivation observed in potentiodynamic curves is due to a surface film formation on a copper electrode. It is concluded that this film must be copper (I) chloride in nature. Effect of different factors on potentiodynamic curves has also been investigated.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
1
6
https://www.ije.ir/article_70971_4f9006fc8906b61e6dc2dfcfda290f90.pdf
The Kinetics of Methanation on Nickel Catalysts
Y. W.
Cehn
Chemical & Petroleum Engineering, National Central University
author
text
article
1988
eng
An empirical rate equation was obtained for the methanation kinetics catalyzed by MCR-2X, a commercial catalyst prepared by Haldor-Topsoe. The studies were carried out in a fixed-bed reactor under differential conditions, and in a gradientless recycle reactor (Berry) over a range of total pressures, reactant concentractions (H2/CO ratios), and temperatures. The kinetics of methanation were found to be of first order in hydrogen at total gas pressures below 7 atm, and of half order at f-uigher pressures. With respect to carbon monoxide the reaction order was -0.46 in the composition range studied . Water vapor, a reaction product, was observed to inhibit the methanation rate. On the other hand, carbon dioxide and methane had no influence on the reaction kinetics. The following rate equation was obtained for the methanation rate with the partial pressure (p) of each component expressed in atmospheres and the rate constant k in mol.g-1 catalyst.s-1:The catalyst was observed to be susceptible to deactivation by hydrogen sulfide in the feed gas. The rate coefficient for deactivation was determined. Its value for MCR-2X was comparable to that of other nickelbased catalysts.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
7
18
https://www.ije.ir/article_70972_d424d937cb2406a7dd9a3e345660a2f7.pdf
Stiffness Matrices for Axial and Bending Deformations of Non-Prismatic Beams with Linearly Varying Thickness
A. B.
Sabir
Civil Engineering, University College
author
text
article
1988
eng
Siffness matrices for axial and bending deformations of a beam having a rectangular cross sectional area of constant width and linearly varying thickness are developed. A consistant load vector for a uniformly distributed lateral load is also calculated, using the principal of potential energy. The matrices are used to obtain numerical results for a variety of beams with non-uniform thickness to show that acceptable degrees of accuracy can be obtained. A comparison of results given by other finite element solutions is made to show the effectiveness of the derived stiffness matrices.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
19
28
https://www.ije.ir/article_70973_08a1ea4f9e4b256877c5a229eef40c73.pdf
Harmonic Response of Pile Groups to Dynamic Loading
J. L.
Meek
Civil Engineering, University of Queensland
author
text
article
1988
eng
A completely general method of analysis for three-dimensional raked piles under harmonic excitation is discussed. The piles have been represented by a three-dimensional frame structure and the soil has been represented by a boundary element discretization scheme. A computer program has been written which carries out this analysis and produces a group stiffness matrix that can be included as a foundation stiffness matrix in the analysis of a superstructure. Results from this analysis have been compared with those available in the literature.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
29
36
https://www.ije.ir/article_70974_3c404a979a1a9066081d9ba802281d0f.pdf
Modeling and Performance Evaluation of Multi-Processors Organization with Shared Memories
M.
Naderi
, Sharif University of Technology
author
text
article
1988
eng
This paper is primarily concerned with theoretical evaluation of the performance of multiprocessors system. A markovian waiting line model has been developed for various different multi-processors configurations, with shared memory. The system is analysed at the request level rather than job level.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
37
46
https://www.ije.ir/article_70975_9cee8ad7e520be13a66bc545d27f4323.pdf
Design of Logic Network for Generating Sequency Ordered Hadamard Matrix H
H.J.
Eghbal Jahromi
Computer Engineering, Shiraz University
author
text
article
1988
eng
A logic network to produce the sequency ordered Hadamard matrix H based on the property of gray code and orthogonal group codes is developed. The network uses a counter to generate Rademacher function such that the output of H will be in sequency. A general purpose shift register with output logic is used to establish a sequence of period P corresponding to a given value of order m of the Hadamard matrix. A logic network to generate sequency Hadamard matrix of order 23 was designed to illustrate the effectiveness of the procedure.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
47
52
https://www.ije.ir/article_70976_cbaa7826157f279af589370c31e5ec73.pdf
Digital Distance Relaying
A. M.
Ranjbar
Electrical Engineering, Sharif University of Technology
author
text
article
1988
eng
Increasing interest is being shown in the use of microprocessor for protection, switching and data acquisition required in modern high voltage substations. One of the most difficult functions to fulfill is that of transmission line distance protection employing samples of the voltage and current waveform taken from high voltage transducer equipment at the usual relaying point. This paper examines and compares different digital algorithms suitable for distance measurement, with particular reference to their accuracy and speed of calculation.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
53
62
https://www.ije.ir/article_70977_829873d17a8246d82d39ed386d5228d0.pdf
Reliability and Availability Analysis of Fusion Power Plants
A.
Husseiny
author
R.
Kenarangui
Electerical Engineering, University of Tabriz
author
text
article
1988
eng
Major efforts are underway to develop fusion energy for use in electric power production in the furture. While fusion reactor concepts are being developed, appropriate attention must be given to problems relvant to the utility requirements which are likely to be encountered in the commercialization phase. In this paper the expected fusion plant availability is assessed in detail due to the importance of power plant availability in the commercialization of the use of any energy source. The reliability and availability of fusion plants are analyzed by using the PREP, KITT–1, and KITT–2 codes (1). Analysis of computer output yields the availability of 82–82.9 percent for a fusion power plant under investigation during one year operation by assuming that there would be two schedule outages for first wall replacement. Also, Exploration of those components which are prone to failure and which may increase the change for forced failures is made.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
63
72
https://www.ije.ir/article_70978_01fc5b21fcc289b6bf743a09a7c8771b.pdf
Sulfur Species in Particulates Emitted from Reducing Coal Combustion and Pyrometallurgical Furnaces
S.K.
Sadrnezhaad
Materials Science and Engineering, Sharif University of Technology
author
text
article
1988
eng
The method of X-Ray Photo-electron Spectroscopy is used to determine the chemical state of the sulfur species present in fly-ash samples produced by burning a number of pulverized coal samples under reducing conditions in a continuous combustion furnace. The influence of submicron metallic constituents present in the flue-gases of the pyrometallurical systems on the state of the sulfur species emitted from the burning chamber and produced on the surface of ZnO particulates is thiosulfate. This material, which is relatively stable at the normal workroom conditions, is not as toxic as previously seen metallic sulfur compounds produced under oxidizing conditions.
International Journal of Engineering
Materials and Energy Research Center
1025-2495
1
v.
1
no.
1988
73
78
https://www.ije.ir/article_70979_0f106dbd47d2548a302d43a7ffcf309c.pdf