Journal of Kufa - physics

In this study, the shell model used to calculate energy levels and reduced electric quadruple transition probability B(E2) for 18Ne isotope using OXBASH code within the sd shell and using the KUOSD effective interaction.18Ne isotope contain two proton outside 16O core in shell (0d5/2, 1s1/2, and 0d3/2) .The results of the energy levels and values of B(E2) were reasonably consistent with the experimental data available.

In optical communication systems, the main aim is to control and limit the unwanted Crosstalk (CT) effects on wavelength divisions multiplexing (WDM) channel, which degrade the transmission performance. To do this, a simple approximate formula was presented for calculating the CT of multiwaveguide directional coupler (DC) using Finite Differences (FD) method. Through this formula, the input power can be controlled to be entered from one specified channel, which is required in some applications. Then, the evolution of the power has been determined without using Beam Propagation Method (BPM). The purpose of this paper is to calculate the CT for arbitrary input channel. Result obtained from this formula are in a complete agreement with the previous works for two and three waveguide directional couplers.

Polymer blends of different concentrations for PVP-K30 and different additive weights of PEG8000 have been prepared as polymeric blends solutions. The rheological and optical properties of the blends samples have been investigated using Ostwald viscometer and Refractometer. The results showed that the density, shear, relative and specific viscosities are increases with the increasing of PVP concentrationand additive weight of PEG. The optical constant values such as refractive index, reflectance, molar reflectance, coefficient of finesse and Brewster Angle are increase with the increasing of PVP concentration and additive weight of PEG while the criticalangle has the revers behavior.

The present work is concerned with the measurements of uranium concentrations infourtynine surface soils samples from selected locations (some of them were measured for the first time as far as authors know) in Al-Diwaniyah governorate by using uranium fission fragment U-235 (n-f), obtained by the bombardment of U-235 with thermal neutrons. The results have shown that, the highest uranium concentration in surface soils samples in the selected regions in Al-Diwaniyah governorate was found in (Al-sdeer) region , which was equal to (8.86±0.89 ppm), while the lowest uranium concentration was found in (Al-shamr 2) region which was equal to (2.50±0.92 ppm) The present results have show that the uranium concentrations in the studied surface soils samples were less than the allowed value (11.7 ppm) recommended by UNSCEAR, 1993

Bethe approximation had been used to compute the excitation cross
section in term of the diploe oscillator strength for some allowed
transitions between energy levels of Li-atom collide with electrons with
impact energy range (2-2000) eV. We also compute the radiation
transition probability and lifetime. Our results for all calculations we
had done were compared with the available theoretical and experimental
data

Bethe approximation had been used to compute the excitation cross
section in term of the diploe oscillator strength for some allowed
transitions between energy levels of Li-atom collide with electrons with
impact energy range (2-2000) eV. We also compute the radiation
transition probability and lifetime. Our results for all calculations we
had done were compared with the available theoretical and experimental
data

The carbon quantum dots (CQDs) were prepared by using an easy
and economic one – pot method. The starting materials are the ascorbic
acid as a carbon source and copper acetate as a catalyst to accelerate the
reaction. The structural and optical properties of the CQDs are studied
by UV-VIS spectrophotometer and photoluminescence (PL)
measurements, transmission electron microscope (TEM), X-ray
diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR).
The excitation wavelength and the pH-dependent of PL properties was
investigated also. The results show that the CQDs have strong
absorption peak in the UV-region. The PL is the excitation wavelength
dependent. The PL of CQDs decreases upon lowering the pH value of
the solutions and the PL peaks shifted to the shorter wavelength. The
average size of the CQDs is 4 nm from the TEM measurements.

This research aimed to study the friction and diffusion coefficients
of neutral atoms that moving and interact with a laser field .The
Mathcad 14 program used to calculate the results. The theoretical model
was solved and shown the effect of different optical parameters on the
diffusion and friction of neutral atoms .The different values of ellipticity
(Ɛ) were used to find the friction and diffusion coefficients ,for each
value of ellipticity we found that the relationship between the natural
width of excited level( γ) and the difference(δ) between the frequency
of laser field(ω) and the atomic resonance (ω0 ) has strong effect on the
friction coefficient of atoms .The effect of Rabi frequency (Ω ) on the
diffusion coefficient has been investigated .In this research the results
showed that each of the parameters δ and Ω has effect on the diffusion
of atom and the Rabi frequency has more influence. The dependence of
the friction and diffusion coefficients on the natural width of the excited
level was studied. The measuring of the friction and diffusion
coefficients of atom very important to control the movement and then
localize it, this have many applications in physics fields.

Using first-principles quantum transport simulations, this work
examines changes in the total electronic currents within the plane of
short ultrathin graphene nanoribbon with armchair edges (AGNR). A 5-
AGNR-M (M = 4,12,20 and 28 zigzag line) junction was simulated and
its transmission were analyzed. The I-V curves under external bias
exhibit remarkable semiconducting characteristics. It further
demonstrates that the length of the junction also showed significant
effects in the determination of the semiconducting nature. More
importantly, a significant increasing by double in bias voltage threshold
of I–V characteristics have been observed for the positively charged
nanoribbon in the family of 5-AGNRs.

This work focuses on the two methods of extraction for dye plant Lantana
Camara (ethanol and water), thin film was synthesized from two solvents by spin
coating method on glass substrates. Theses dyes were characterized by the
measurement of Fourier transform infrared spectrophotometer FTIR, the result
showed that the film had the chemical structure for flowers of lantana camara of two
methods in rang (4000-400 cm-1
). The measurement the optical properties of the films
were studied by using UV spectrophotometer. The range absorbance spectrum has
been recorded at wavelength with in the (300-1000) nm. The optical absorption (A) for
the peak of ethanol was 0.93 in the wavelength 330 nm while for extraction water
was 0.7 in the wavelength 330 nm ,determined the optical constants such, as
absorption coefficient (α) was less than of 104
that value of ethanol and water
extraction , an extinction coefficient (k) was low value between (0.2-0.25) .and was
found optical energy gap from extraction water (2.4) eV ,and the optical energy gap of
extraction of ethanol was found (2.25) eV.

Radiation pollution become a major problem threatening the life on
the earth that causes many of the serious diseases, through acute or
chronic effects. The leukaemia this considered to be the most serious
and common disease due to the increasing of radiation pollution levels.
In this study the province of Basrah was selected because this province
contains many of the wars remnants due to the Gulf Wars (1991, 2003).
The aim of this study is to investigate the possibility of any a
relationship between the radioactivity level and leukaemia incidence;
there are a direct or indirect relationship between the cancer rate and the
exposure to radiation. Therefore, the levels of different radionuclide in
leukaemic patients. In order to achieve our goal 75 samples were study
and many techniques are utilized, such as the SAM 940 TM (Gamma ray
Spectroscopy). In addition, to compare between the healthy and
Leukaemic samples, the UV-Vis spectrometer has been used. The
results showed that there is a big difference between the radionuclide’s
concentrations of the healthy and patients samples. For example, the
238U concentration in several Leukaemic patients were (2.0958 Bq/Kg),
whilst at healthy individuals were (0.408 Bq/Kg).

This work studies the gain from plasmonic quantum dot (QD)
nanolaser. A metal/semiconductor/metal (MSM) structure was
considered to attain plasmonic nanocavity with active region contains:
QD, wetting layer (WL) and barrier layers. Band alignment between
layers was used to predict their parameters. Momentum matrix element
for transverse magnetic (TM) mode in QD structure was formulated.
Waveguide Fermi energy was introduced and formulated, for the first
time, in this work to cover the waveguide contribution (Ag metal layer)
in addition to the active region. High net modal gain was obtained when
the waveguide Fermi energy was taken into account which means that
the increment comes from the material gain not from the confinement
factor. The change in waveguide Fermi energy in the valence band
explained the high gain, where the valence band QD states are fully
occupied referring to an efficient hole contribution.

In this study, the spectral analysis technique was used to calculate the
electron temperature and density of argon gas using the ratio method
between the two spectral lines. These parameters were calculated at
different pressures (0.375, 0.75, 1.5, 1.875, 2.25 torr) and voltages (240,
250, 260, 270, 280 volt). The results showed that the temperature of the
electron increases by increasing the voltage and decreases with
increasing pressure, while the density of the electrons increases by
increasing the voltage and the pressure. where the temperature of the
electrons was calculated and it was at the limitations of (0.28 - 0.54eV),
As for the density of electrons was at the limitations of (1.5 × 1012
- 3.7 ×
1012
cm – 3
) .