Iraqi Journal of Physics

Early detection of eye diseases can forestall visual deficiency and
vision loss. There are several types of human eye diseases, for
example, diabetic retinopathy, glaucoma, arteriosclerosis, and
hypertension. Diabetic retinopathy (DR) which is brought about by
diabetes causes the retinal vessels harmed and blood leakage in the
retina. Retinal blood vessels have a huge job in the detection and
treatment of different retinal diseases. Thus, retinal vasculature
extraction is significant to help experts for the finding and treatment
of systematic diseases. Accordingly, early detection and consequent
treatment are fundamental for influenced patients to protect their
vision. The aim of this reseaech is to utilized image processing
techniques to detect blood vessels from the digital fundus images.
This research will present a methodology to separate retinal blood
vessel network. The suggested system in this research involves four
stages, after image acquisition, the pre-processes of the image to
preparing and improving the image quality is the first stage.
Morphological operations are used for the detection of blood vessels.
In this research, we use two morphological operations: erosion and
dilation. These two tasks have two sources of info, a binary image,
and a structuring element object. We utilize two morphological
procedures ((boundary extraction and Top, Bottom Hat transform).
Before these operations, we will use applying a canny edge detector
technique to obtain the edges of the retina image. The technique is
tried on shading retinal images acquired from STARE and DRIVE
databases which are accessible on the web as well as the samples of
retinal images were obtained from the digital camera from Ibn
Al-Haytham specialist Hospital for Eye in Baghdad, Iraq. The results
obtained from these techniques showed the efficiency of these
methods in the detection of blood vessels, especially when using
morphological methods after the detection of edges.

In this work, analytical study for simulating a Fabry-Perot bistable
etalon (F-P cavity) filled with a dispersive optimized nonlinear
optical material (Kerr type) such as semiconductors Indium
Antimonide (InSb). Because of a tradeoff between the etalon finesse
values and driving terms, an optimization procedures have been done
on the InSb etalon/CO laser parameters, such as critical switching
irradiance (Ic) via simulation systems of optimization procedures of
optical cavity. In order to achieve the minimum switching power and
faster switching time, the optimization parameters of the finesse
values and driving terms on optical bistability and switching
dynamics have been studied.
For different values of a cavity finesse (F=25 and 2.37) the switching
intensity takes low values with a high finesse etalon compared to a
high switching intensity with a low finesse etalon. So, the minimum
switching power for a low finesse etalon is about 0.785 mW, and is
about 0.0785 mW for a high finesse etalon. The driving term peak of
a high finesse etalon becomes higher and the slowing down region
becomes less, leading to a fast switching about 300 ns for low finesse
etalon, and about 150 ns for a high finesse etalon.

This research investigate the effect of uncoated and coated
chopped carbon fibers with alumina Al2O3 or Tri calcium phosphate
(TCP) on the impact value of acrylic poly methyl methacrylate
(PMMA) denture base resin. To improve bonding between carbon
fibers and coating materials powders, the surface of carbon fibers has
been treated with Para amino benzoic acid (C7H7NO2) and poly vinyl
alcohol (PVA) was also used. The morphology of the coating layers
has been examined by field emission scanning electron microscope
(FE-SEM). According to the tests results, PMMA reinforced with
uncoated chopped carbon fiber presents high impact strength value
with bad aesthetic. Samples prepared by coated carbon fiber with
Al2O3 or TCP have high impact strength values when compared to
control group with good aesthetic. The measured value of impact
strength shows a noticeable increase accordingly with the increase of
PVA and decrease of used fiber.

The calculation of the nuclear charge density distributions ρ(r)
and root mean square radius (RMS) by elastic electron scattering of
medium mass nuclei such as (90Zr, 92Mo) based on the model of the
modified shell and the use of the probability of occupation on the
surface orbits of level 2p, 2s eroding shells and 1g gaining shell. The
occupation probabilities of these states differ noticeably from the
predictions of the SSM. We have found an improvement in the
determination of ground charge density and this improvement allow
more precise identification of (CDD) between (92Mo-90Zr) to
illustrate the influence of the extra two protons on the charge density
distributions and was agree with those of experimental data and
Hartree.– Fock. (H.F) wave functions.

In this study, the effect of pumping power on the conversion
efficiency of nonlinear crystal (KTP) was investigated using laser
pump-power technique. The results showed that the higher the
pumping power values, the greater the conversion efficiency (η) and,
as the crystal thickness increases within limitations, the energy
conversion efficiency increases at delay time of (0.333 ns) and at
room temperature. Efficiency of 80 % at length of KTP crystal
(L = 1.75 X 10-3 m) and Pin = 28 MW, and also, compare the
experimental results with numerical results by using MATLAB
program. The contribution of this technique is measuring ultrafast
phenomena inside matter such as the movement of atoms or electron
excitations.

In this work, pure Polypyrrole (PPy) and Polypyrrole (PPy)/
Graphene (GN) was synthesized by in-situ polymerization with
different weight percentages (0.1, 0.3, 0.5, 1, 3 and 5 wt.%) of GN
nano particles using chemical oxidation method at room temperature.
The FTIR, SEM and electrical properties were studies for the nano
composites. The result show that when concentration of GN Nano
particle increase, the electrical conductivity increased and the
graphene sheets were merging to form a continuous area of the GN
through the polypyrrole base material. The FTIR spectra shows that
the characteristics absorption peaks of polypyrrole that is,1546.80,
1463.87 and 3400.27 cm-1 (stretching vibration in the pyrrole ring),
and at 1080.06 cm-1 was assigned to C—O stretching and at 1589.23
cm
-1 was assigned to C—C vibration of carbon ring in graphene.

Highly-fluorescent Carbon Quantum Dots (CQDs) are
synthesized in a simple step by hydrothermal carbonization method
of natural precursor such as orange juice as a carbon source.
Hydrothermal method for synthesized CQDs requires simple and
inexpensive equipment and raw materials, thus this method is now
common synthesis method. The prepared CQDs have been
characterized by X-ray, AFM, SEM, FTIR and fluorescence
measurements with Stilbene 420 dye. It has found that the
synthesized CQDs have amorphous structure and possess ultrafine
size up to few nanometers and contains of carbon, oxygen based
groups and surface-modified functional groups. Moreover, the
prepared CQDs derived from orange juice have extremely good
fluorescence. It showed an improvement in the optical properties
when mixed with the Stilbene 420 dye.
This work demonstrates the method of preparing highly
fluorescent CQDs also briefly introduces the most commonly used
techniques for characterizing CQDs and the results obtained and
studying their optical properties by adding Stilbene 420 dye in a
method that changes the input power of used laser.

The nuclear structure of 40Ar, 112Cd, 133Cs, 151Eu, 154Sm, and 226Ra
target nuclei used in nuclear battery technology has been investigated
in the framework of Hartree-Fock approximation based on Skyrme
effective two-body interaction. These nuclei are extensively used in
radioisotope thermo-electric generator space studies and for beta
voltaic battery microelectronic systems. For this purpose, some static
nuclear properties have been calculated. In particular, the various
nuclear single particle radial density distribution, the corresponding
root mean square radii, neutron skin thicknesses and binding
energies. The bremsstrahlung spectrums produced by absorption of
beta particles in beta voltaic process and the backscattered photon
spectrum have also been calculated. All obtained results are
compared with available experimental data.

In this paper, Pentacene based-organic field effect transistors
(OFETs) by using different layers (monolayer, bilayer and trilayer)
for three different gate insulators (ZrO2, PVA and CYEPL) were
studied its current–voltage (I-V) characteristics by using the gradualchannel approximation model. The device exhibits a typical output
curve of a field-effect transistor (FET). Source-drain voltage (Vds)
was also investigated to study the effects of gate dielectric on
electrical performance for OFET. The effect of capacitance
semiconductor in performance OFETs was considered. The values of
current and transconductance which calculated using MATLAB
simulation. It exhibited a value of current increase with increasing
source-drain voltage.

The plasma holmium produced by a 1064 nm Nd:YAG
Q-switched laser in air was investigated. This work was done
theoretically and experimentally. Cowan code was used to get the
emission spectra for different transition of the holmium target. In the
experimental work, the plasma evolution has been studied by
acquiring spectral images with different laser pulse energies (600,
650,700, 750, and 800) mJ, with The repetition rates of (1 Hz and
10 Hz). In the UV region (200-400) nm. The results indicate that, the
emission line intensities increase with increasing of the laser pulse
energy and repetition rate. The strongest emission spectra appeared
when the laser pulse energy is 800 mJ and 10 Hz repetition rate at
λ= 345.64 nm, with the maximum intensity of 77000 counts.

Chaotic properties of nuclear energy spectrum in 68Ge are
analyzed using the framework of the nuclear shell model. Nuclear
energies of considered states are obtained via performing f5p shell
model calculations using the OXBASH computer program together
with the effective interaction of F5PVH. The 68Ge nucleus is
suggested to consist of a core 56Ni with twelve particles (8 neutrons +
4 protons) in f5p-model space (2????3⁄2 , 1????5⁄2 and 2????1⁄2). The density
of energy level of studied classes have been found to have a form of
Gaussian, which is in accord with the prediction of other theoretical
studies. The distributions of the spacing P(s) and ∆3 statistic for the
studied states are well described by the Gaussian orthogonal
ensemble (GOE). Furthermore, these fluctuations are independent on
the spin J.