Kirkuk Journal of Science

prestressing is the deliberate creation of permanent internal stresses in a structure or
a system in order to improve it’s performance under service loads. Such stresses are
designed to counter act those induced by external loading. The application of prestressed
concrete is widely used and is in away a natural result. Concrete is strong in compression
and weak in tension. Prestressing the concrete would produce compressive stresses which
will counteract tensile stresses induced by external loading, thus producing a crack-free
material during service-steel is strong in both compression and tension. The benefits of
prestressing composite steel beam are to increase the elastic strength, to reduce deflection
with limited member depth, to reduce steel weight, to increase ductility by redistribution of
internal stresses, and to improve fatique strength of a structural detail by reducing the
tensile stress range.
Presteressing mechanisms and bending behaviour of prestressed steel beam are very
important to fully utilize the member section. The analysis equations for the elastic state
and fully plastic state are developed based on equilibrium of forces and compatibility of
deformation. The comparison between bounded and unbounded tendons shows that the
bond of the tendons in prestressed steel beams has small effect in improving their behavior.
Beams with draped tendons are compared with beams with straight tendons. Draping the
tendons reduce the shear stresses in the beam. The magnitude of the reduced shear stresses
depends on the depth of the beam and the tendon profile.

In the present investigation, a laboratory study of scour characteristics
downstream weirs, compound gates has been conducted. The study included the
measurement of maximum scour depth and the length of scour hole downstream these
structures. Also, the effects of structure height, under sluice opening height, discharge
variation and the diameter of bed material on the depth and length of scour hole. Two
hundred and thirty four experiments were conducted in a concrete laboratory channel.
Three sizes of crushed aggregate in range of (1.43-2.21)cm and three of gate height 15,
20 and 30cm were tested . Three heights of gate openings 1, 2 and 3cm were also tested.
Experimental Results of this study showed a good direct relationships between relative
scour depth (Ds/D50) and relative scour length (Ls/D50) with densimetric Froude number
(Fro) for weirs and compound gates. It was also shown that (Ds/D50) and (Ls/D50) have
good relationships with the relative discharge (qu/qd) for all cases and bed materials of
compound gates. Two empirical relationships were obtained to estimated (Ds/D50) and
(Ls/D50) in terms of (Fro) and relative water surface fall (ΔHw/P) for weirs with high
determination coefficients. Another two empirical relationships were obtained to
estimated (Ds/D50) and (Ls/D50) in terms of (Fro) , relative water surface fall (ΔHt/P) ,
relative opening height (h0/ΔHt) and relative discharge (qu/qd) for compound gates with
high determination coefficients.

The method is proposed to study the performance of single-phase capacitor motor
with amplitude control. This is clearly shown by controlling the speed of the motor with
varying the applied voltage to the control voltage while the excitation voltage is
constant. The obtained results show the validity of the method and the accuracy of the
equations derived in this work.

An experimental study on free convection heat transfer from a horizontal array
consists of three cylinders heated under the condition of constant surface temperature
was carried out. The study included clarifying the effect of separation distance between
the cylinders and the distance that separate them from a floor, on the natural convection
heat transfer from the array.
The study showed that the ability of the cylinders to transmit heat with free
convection is a function to separation distances between the cylinders also the distance
between the cylinders and the floor, as well as Rayligh number, this ability is decrease
too much when the separation distance from the floor and the neighborhood cylinder is
small, the reduction in heat transfer for the center cylinder was (40%) in comparison
with single cylinder test at vertical and horizontal separation distance of (1/8), the
thermal performance for both cylinders may be got better as the separation distance
increase, where the maximum enhancement in heat transfer for the center cylinder was
recorded as (11%) in comparison with single cylinder test at vertical separation distance
of (1) and horizontal separation distance of (3/4).
The experimental results showed that the enhancement in heat transfer increases as
the separation distance from the floor being larger, and the maximum heat transfer at
small heights may be at high Rayligh numbers, where for high separation distances, the
maximum relative enhancement may be observed at low Rayligh numbers.

Theoretical and experimental study was carried out of heat transfer by forced
convection from the cylinder in cross flow embedded in a saturated porous media. the
theoretical part of the work includes solving the standard energy transport equation in
porous media regions by FLUENT. there are maximum temperature and minimum
velocity at the rear of cylinder
0
  0
but minimum temperature and maximum velocity
at the front of cylinder
0
 180
. the stagnant area at
0
  0
and the separation at
0 0
  90 and  270 .. The experimental part of this work included the construction of
an experimental model composed of cast iron cylinder with a (18 mm) inner diameter
and (20mm) outer diameter with a length of(200mm) heated internally by an electrical
heater. The cylinder was embedded in a packing of glass ball with diameter (12mm)
placed in across flow wind tunnel. The experimental results revealed that the average
heat transfer increased when the Peclets number and Reynolds number increased for
steady state condition. The relationship between Na&Re and Na&Pe for experimental
gives us Nu=alnRe-b and Nu=2Pe-2.666 respectively when a and b are constants
depending on Re and Q for
20  Q 120
(Q in watt) and
2000  Re  3000
10.087  a  27.61 , 66.33  b 183.6 .

18 samples of soil were collected from selected places in Al-Tamim governorate
and these samples were measured by using Gamma ray spectrum system represented by
Germanium high purity (HPGe) with energy resolution 2.2 KeV at the energy 1332
KeV of Co60. The system was attached to the computer where the spectrum was
collected and analyzed by the PCA program which is a comprehensive program for
spectral and quantity analysis of Gamma ray. The radiatary activity of radiating nuclides
resulting from the chain of U238,U235, K40 and Cs137 were calculated .
The ratios Th234 /Ra226, was found (0.828 – 0.969), Th234 /Pa234m, was found to be
(0.805 – 0.954).The value of R which represents U235/ U238 was counted and it ranged
between (0.00562-0.00602) for the samples of polluted soils and (0.0064-0.0071) for the unpolluted soil. The value of R in the soil 100% polluted with the depleted Uranium
Equals 0.00351.The present study proves the existence of high concentrations of Cs-137
exceeding (11 Bq/Kg).

Brucellosis is a zoonotic disease, endemic in Iraq, and transmitted through dairy
products. Several serological tests have already been used for Brucella infection
diagnosis. Sera from a total 182 suspected patients having brucellosis attended Azadi
General Hospital during the period between June – September 2009 had been screened
by different serological tests, Rose Bengal agglutination test, B.abortus antigen
agglutination test, B.melitensis antigen agglutination test as well as ELISA IgM, IgG
have been used in this investigation to determine the type of infection and to evaluate
the best serologic tests . By comparing the results obtained from these serologic tests
and by using statistical methods (PPV, NPV and F-measure) it was found that the Rose
Bengal test is most useful and more sensitive than other two tests B.abortus antigen test
and B.melitensis antigen test. There have been no significant differences between the
rate of acute and chronic infection. The result also suggested that the male and female
have the same susceptibility for infection with Brucella.

Studying the water quality of Erbil waste water, and how much it match with the world
criteria to irrigation purpose, during Spring 2007 to Winter 2008 , ten stations within and
along the city wastewater channel were chosen , the first formation (Qalaa in the city
centre) till the last gathering station to form the main channel in the southern west of the
city (Areb qand).Important measurements were taking in consideration :T. coliform, TP,
TN, BOD5, COD and TSS .The main results were :
* The seasonal values followed certain rhythm which was; Summer > Spring > Winter .
* Only for the reason of high number of T. cliform in the studies season except the winter
season which was in low value, the wastewater in the main channel match to irrigation
purpose only in Winter season.

In this research effect caused by X-Ray on the properties of AlGaAs laser has
been carried auto at different times ,there properties include the I-V and I-P at 180oC.
It is noted that these properties has change when the laser is exposed to X-ray
radiation also the stimulated emission is completely eliminated at moderate exposure
times, but at longer exposure times (45-90)min the laser break down and both
stimulated and spontaneous emission were completely disappear. Creased with the
disappearing of each at the catalytic spontaneous resurrections.

This study aimed to estimate and analyze the prevalence of different normal, benign
and abnormal cellular changes based on cytological diagnosis.
The study included 236 women undergoing cytological exams in obstetric and pediatric
hospital in Hawler city. It revealed 4(1.6%) cases of various grades of CIN, 5(2.1%)
cases of atypical squamous cells (ASC), 67(28.3%) cases of reactive cellular changes
(RCC) and 71(30%) cases of squamous metaplasia. The relation of these conditions to
the development of cervical cancer is discussed.
Furthermore, different cervical and vaginal infections were identified by cytological
means, including 21(8.8%) cases of Gardnerella vaginalis, 11(4.6%) cases of Candida,
9(3.8) cases of Trichomonas vaginalis, 2(0.8%) cases of viral infection, and 45(19%)
cases of nonspecific infection.In some cases more than one lesion is present in the same
smear.

This study aims at designing optic fibers out of the doped silica and studying the
properties of the manufactured optic fibers and employing them in different practical
processes . Three types of doped silica will be chosen :
(13.5 m / 0 GeO2, 86.5 m / 0 SiO2)
( 9.1 m / 0 GeO2,7.7m/0B2O3, 83.2 m / 0 SiO2)
( 4.03 m / 0 GeO2, 9.7m/0B2O3, 86.27m / 0 SiO2)
By using sellmeire equation the refraction index will be calculated for the materials
used in manufacturing optic fibers. The study shows that the materials (13.5 m / 0
GeO2, 86.5 m / 0 SiO2) has the highest index of refraction among the other materials by
using special equation, the properties of optic fibers has been examined ( the numerical
aperture , the critical angle ,…) as a function of wave length. The result shows that the
core optic fiber has the doped silica (13.5 m / 0 GeO2, 86.5 m / 0 SiO2) while the clad
has the material (9.1 m / 0 GeO2,7.7m/0B2O3, 83.2 m / 0 SiO2) this should be of suitable
properties to act as a receiving fiber. The fiber of the core materials (13.5 m / 0 GeO2,
86.5 m / 0 SiO2) while the glade has the materials (4.03 m / 0 GeO2, 9.7m/0B2O3,
86.27m / 0 SiO2) have properties which enabled it to act as a sending fiber with various
wave length.

The objective of the study is for using remote sensing and GIS techniques for
monitoring the changing of landuse and vegetation therefore we studied the change of
landcover types during the years (1987-2007) in selected areas arrive at 273700ha for
Kirkuk governorates from Iraq .Image of Landsat taken by (Thematic Mapper) TM for
year 1987 and ETM+ for year (2007) were used . image classification are done for
allocation land cover types by using ER-Mapper V 6.4 program. The results indicated
that there are six abundant classes of landcover including soils
1&2,vegetations1&2,urban and water .Also clear changing of land cover areas observed
during the year (1987 to 2007 )including reduction of soil\2 and water areas in( 2007)
by 12%and 0.01% respectively ,but vegetation\1&2 , urban and soil\1 were increased
about 3.5 %, 0.19%, 1,0% and 7.31% respectively

The optical properties of polymer composite polycarbonate-polystyrene
(PC-PS) films prepared by casting technique were studied in the visible and
ultraviolent wavelength regions. It was found that the optical absorption is
due to direct allowed transitions for pure and composite polymer films,
while the energy gaps and the width of the tail localized states of the
composite was lied in the mid values of the pure samples. The optical
constants refractive index , extinction coefficient , the real and the
imaginary parts of the dielectric constant have been also calculated. The
dielectric constant and refractive index become more stable for composite
sample.

This investigation was conducted for two successive years (2000 and 2001) in the
experimental field of Qlyasan research station-college of Agriculture-University of
Sulaimani, to study the effect of Nitrogen fertilizer (0, 20 and 40 kgN/ha) and two
cutting treatments (one cut and two cut) on the characters of plant height, No. of
tillers/plant, Green and dry leaf%, Green and dry stem %, dry matter%, green and dry
weight/plant, leaf dry weight, stem dry weight and green and dry forage yield for proso
millet.
Results of combined analysis for two years indicated the presence of significant
effect of Nitrogen fertilizer on plant height and green forage yield only. Concerning
cutting treatments on studied characters as the average of two years, results indicated
the out yielding the treatment of two cut in plant height, green and dry leaves%, green
yield/plant, while the treatment of one cut out yielded two cuts in green and dry stem%,
dry matter %, dry stem yield and dry forage yield, in which there are no significant
effect of cutting treatment on No. of tillers/plant, dry weight/plant, dry leaves yield and
green forage yield.
Concerning to the interaction effect between the two factors levels, the results of
combined analysis indicate no significant effect on all characters except of plant height.

In this paper we modified Newton – Raphson and Secant methods to Complex
form, then from that we get new iterative formula to them, named Newton (Secant) real
iteration formula and Newton (Secant) imaginary iteration formula, real iteration used to
find real roots while imaginary iteration one will be used to find complex roots of nonlinear equations such as (
0
2
x  a 
). To find real roots, we start with a real initial
point in real iteration getting a sequence of real numbers, to find complex roots start
with a complex initial point in complex formula getting a sequence of complex
numbers, also we write a new algorithm for this technique and write the program by
using Matlab application system version 7.8 for this new method such that it will
determine the real roots when we enter the initial real point but when we enter the initial
complex point it will determine the complex roots.