A Transformer With Saturable Two-port Core
دکتر حسین
محسنی
author
مهندس کاوه
نیایش
author
text
article
1995
per
The behaviour of power transformers is very like to
ideal ones. Their characteristic matrices can not be
determined directly, because the elements of the
characteristic matrices are either close to infinity or zero.
On the other hand, strong coupling between two
transformer windings causes the determinant of these
matrices to become zero. Therefore, conversion of these
matrices to each other will decrease the precision of
results.
In this paper, we define three new parameters, d,
Zo.c.(open - circuit impedance) and Zs.c. (short-circuit
impedance). Using these parameters; we develop a new
method for determination of the characteristic matrices of
such transformers, and we show that this method does not
lead to a major decrease in the precision of results. All
characteristic matrices are obtained by this method and
some equivalent circuits for such transformers have been proposed.
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26252_380351574bff23d0e311f266933c9331.pdf
Far Field Vector Analysis of the Dielectric Fresnel Zone Plate Antenna
دکتر فرخ
آرزم
author
مهندس علیرضا
شوشتری
author
text
article
1995
per
A vectorial analysis of the Fresnel Zone plate antenna
(FZPA) with a dielectric layer for changing the phase of
the incident wave has been presented. The radiation
properties of the feed are chosen as a raised cosine
function power pattern approximation with no cross
polarization. The electric field on the aperture plane has
first been found, then the radiation field, gain and
efficiency have been obtained by "equivalence magnetic
currents".
Several FZPA are fabricated and experimental results
show a good agreement with the theoretical study.
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26253_1cc77caa04615e2e26a1f4460d832a40.pdf
The Effect of Seismic Waves on Buried Gas pipelines
دکتر خسرو
برگی
author
مهندس غلامرضا
هروی
author
text
article
1995
per
In this paper, the behaviour of buried pipelines under
the effect of propagation of seismic waves and faulting is
studied seperately.
The stability of this type of structure was first studied
by using three different methods proposed by
Newmark-Hall, kenndey et al. and Wang - Yeh under the
effect of ground faulting. By parametric study, the effect
of soil types, size of pipeline, depth of embedment, the
incident angle of fault with pipline, the type of fault, the
supporting conditions of the pipeline in the vicinity of the
fault are analyzed and some technical recommendation
are presented.
Finally, by using a lumped model for the pipeline
structure, it is analyzed by using, the step-by-step method
of Wilson - ?. The effect of the most important
parameters on the pipeline are mentioned and based on
the implemented analysis, some applicable rules are recommended.
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26254_a70ab920f8becaea5b13ca9d6a378f4a.pdf
he Reaction Rate of Phithalic Anhydride With Urea in the Presence of Acetic Acid From the Freezing Curve
دکتر سید محمد علی
موسویان
author
مهندس مجید
واحدی
author
علیرضا طالبی زاده
رفسنجانی
author
text
article
1995
per
Antranilic acid is an intermediate material which we
can produce by Hofmann's rearrangement reaction. In
this process phithalimide is a main reactant. One
procedure for produceing phthalimide is the reaction of
phithalic anhydride with urea in the presence of acetic
acid. In this research, the kinetics of this reaction was
studied at 115 C. We found that the reaction of phthalic
anhydride and urea is a second order reaction. The rate
constant was 0.OS1 liter/mole minute.
In determining the rate constant, the freezing curve
for the binary mixture of phthalimide and phthalic
anhydride was also obtained. It was found that the
optimum initial ratio of urea to phthalic anhydride is in the range of 1-2.
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26255_bfb960aefe1bb625eee869784e3bf136.pdf
Direct Smelting of Steel: Process Simulation
دکتر خطیب الاسلام صدر
نژاد
author
مهندس عبدالرضا
سیمچی
author
text
article
1995
per
The Design and manufacture of direct smelting
reactors depends on the rate of the physico-chemical
reactions that occur in the particles immersed into the
molten bath. Investigation of the effects of the important
parameters that influence the smelting rate of the
particles that in the furnace are both difficult and
expensive if the aimed is to take measure meuts under
real practical conditions. It is feasible of simulate the
process through application of the physico-mathematical
models that may be capable to predicting the influence of
the important variables such as (a) type and dimensions
the furnace, (b) analyses of the materials, and (c) size and
rate of feeding the particles. In this paper, the operational
conditions required to maximize the rates and the
efficiencies of heating, reduction, melting and purification of the reactor is investigated.
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26256_66670c504c8a80015baac429bc628d55.pdf
Modling and Interpretation of a Magnetic Anomaly
in Saghand-e-Yazd.
دکتر غلامحسین
نوروزی
author
text
article
1995
per
Following a magnetic survey in Saghande Yazd region,
the existance of a relatively important dike shape anomaly
was detected.
In the present study, this anomaly has been
interpreted by the Werner deconvolution method and
Parker standard curves.
The location and depth of the uper surface of
magnetic dike has been calculated by the Werner method
using a series of profiles perpendicular to the strike of the
dike. The depth of the dike was determined by
comparison of the variation along one of the profiles
(BB') with Parker's standard curves.
Finally by fitting the experimental anomaly variation
curve to the resultant curves for different thicknesses, the
optimum thickness of the dike has been selected
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26257_b34a7e8f0e358fadc3be287abb4841d5.pdf
Banki Turbine Evaluation and its Future
دکتر غفار
جهانگیری
author
مهندس علیرضا
انتظاری
author
text
article
1995
per
Prior Experimental and theoretical background of the
Banki water turbine has been briefly presented.
Theoretical values of unit quantities have been compared
with published experimental data as well as data obtained
in the hydraulic lab at the University of Tehran; from
which, shortcomings of the existing theory in predicting
the turbine performance has been highlighted. Factors
responsible for the deviation of turbine performance from
the existing theory has been discussed; an algorithm for
developing the appropriate theory and several areas for
future experimental research has been proposed
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26258_09513e148ce782e3bed5a9b9c8b61173.pdf
Design of a Self Tuning Voltage Regulator for
Synchronous Generators
دکتر حمید
لسانی
author
مهندس محسن شفیعی
خور
author
text
article
1995
per
This paper presents a self-tuning PID (Proportional
and Integral and Derivative) controller for regulating
terminal voltage synchronous generators. In order to
modify the system reponse and to overcome the
difficulties of self tuning controllers, a Dual Rate
sampling control system was used. System results
demonstrated usfulness of the proposed regulator. The
designed controller is simple and can be applied in the actual power system.
University College of Engineering
دانشکده فنی
0803-1026
56
v.
0
no.
1995
https://jfe.ut.ac.ir/article_26259_084bb707f89fdf448af8e4f0b6200f61.pdf