Kirkuk Journal of Science

To enhancement the superconductor structural characteristics, nanoparticles of the Al2O3
were added to the samples under study. The Samples of high temperature superconductors 1-
X (Bi2Ba2Ca2Cu3O10+????) + X(Al2O3) with X= (0-0.9) were prepared by solid state reaction
method under hydraulic pressure 8 ton/cm2
and annealing temperature 800℃. Electrical
properties of the samples showed that Tc increases from 126 K to 139 K, and also oxygen
content in samples increased with increasing X values from 0 to 0.5, while Tc decreased less
than 77 K with increasing X at values more than 0.5. In Structural properties, the X-ray
diffraction of the samples showed orthorhombic phase with a=4.286A°, b=5.4184A°,
c=35.3528A° at X=0, while c-value is increased to 35.9848A° at X=0.5. AFM results shows
that the average grain size of the best sample was 47.67 nm at X=0.5. SEM it showed that
there are dark regions related to the heavier elements, such as Bi and Cu, and light regions
related to lighter elements, such as Ba and Ca, depending on atomic weights

Hydrogen is considered one of the most promising source of clean and renewable energy
as an alternative for environment polluting fossil fuel resources. The safe and reasonable
volumetric density storage represent the main problem facing the hydrogen technology. Most
of the research nowadays are focusing on development of new technologies for solid state
storage of hydrogen. At the present study, The adsorption of hydrogen molecule (H2) has been
studied on the supercell (3 x 3 x 1) of pure graphene and doped graphene with boron atom
and adsorbed with lithium atom by first principle calculations with DFT method. We choice
local density approximation (LDA) To describe the exchange-correlation energy between the
interacting electrons and the basis set (Double Numerical Plus polarization DNP), the regions
of a Brillion zone are set to (2 x 2 x 1). The binding energy of hydrogen molecules adsorbed
on the surface of graphene adsorbed by the lithium atom was between (0.2-0.4 eV) and with a
storage ratio (6.74 wt.%), Which meets the gravitational capacity standard specified by the
energy department, And the binding energy of hydrogen molecules adsorbed on the surface of
graphene adsorbed by the lithium atom and doped with the boron atom was between (0.23-
0.32 eV) and with a storage ratio (6.67 wt.%), Thus meeting the standard for the final mass
capacity (6.5 wt.%) Specified by the Department of Energy. We conclude that the doping of
the boron atom into one of the six graphene rings in the large unit cell (3 × 3 × 1) played a
major role in increasing the stability of the graphene surface and reduce the binding energy
that contributes to reducing the temperature of the hydrogen desorption process.

Flame thermal spraying technology was used in the production of 25% zirconia
composite material with 25% alumina particle with binder material of 50% Al-Ni alloy base
on 316L alloy steel base, after preparation the base surface with a method of roughing the
granular. Spraying was carried out using a spray distance (12,14,16,18,20) cm. Hardness tests
were carried out on the composite material to study the effect of changing spray distance on
the properties of the resulting layer. The thermal treatment was performed on the samples at
(850,950,1050,1150) ℃ for an hour. The results of the tests confirmed that the best spraying
distance (16 cm) and the thermal treatment (1050℃) have a significant effect on improving
the hardness of the layers of the composite material.

This study included the synthesis of O-carboxymethyl chitosan which contains
amine group attached directly to its glucose unit from the well-known natural
polymer (chitosan), which in turn was reacted with some aromatic aldehydes
containing o- and p- substituents to prepare a series of Schiff bases compounds. The
used aldehydes were; p-boromobenzaldehyde, o-hydroxybenzaldehyde, obromobenzaldehyde, p-chlorobenzaldehyde, and p-nitrobenzaldehyde. The
synthesized compounds were characterized using spectroscopic techniques including
FT-IR and 1H-NMR. The thermal stability of some of the prepared compounds was
checked using differential thermaogravimetric analysis DTA. Finally, the biological
activity of two Schiff bases was measured against two types of bacteria (Escherichia
coli) and (Staphylococcus aureus) in terms of inhibition rate.

In this research, the months of comfort and discomfort were identified using the
Temperature-Humidity Index in selected stations in Iraq (Mosul, Baghdad, Basra) using data
of the temperature and relative humidity values of the period (1983-2019) obtained from the
Iraqi Meteorological organization and Seismology. The results showed that the months of
discomfort in the three study stations were (January, July, August, December), while the
months of comfort in the three study stations were both (April, September), while the months
(February, March, June, September, November) alternated between comfort and discomfort in
the three study stations .This research also clarified the effect of both temperature and relative
humidity on the values of the Temperature-Humidity Index by clarifying the nature of the
relationship between them by calculating the coefficient of correlation using Microsoft Excel
(2010), where the results showed a linear strong correlation between temperature and
Temperature-Humidity Index values, where the values of correlation coefficients ranged
between (0.996) – (0.997), while the correlation was inversely strong between relative
humidity and Temperature-Humidity Index values where the values of correlation coefficients
ranged between (-0.985) – (-0.959) in the study stations, this indicates that the increase in the
value of temperature and decrease relative humidity leads to an increase in the values of the
Temperature-Humidity Index, and vice versa.

Pure Zinc oxide and ZnO/SeO2 oxide thin films were prepared successfully by sol gel
method and annealed at different temperature under ambient condition. These films were
characterized by means of XRD, AFM, and UV-visible. XRD patterns clearly showed the
presence of crystalline ZnO/SeO2 particles, the ZnO/SeO2 film showed a good crystallinity
like pure ZnO film, Optical transmittance spectra of films showed high transparency (>87%)
in visible region. The color coordinate and tristimulus value of transmittance spectral showed
that the best decolourization result was achieved at 7.5 at.% Se at 400oC, 600oC and 10 at.%
Se at 500oC , for the best brightness result appeared at two point with 2.5 at.% Se at 600oC
and 7.5 at.% Se at 400oC. AFM studies reveal that rms roughness of the thin films increased
with the increasing of Se concentrations. Also, the surface roughness increased with the
increasing of the annealed temperature.