Iraqi Journal of Physics

Exploding wire Technique is a way for production metal and its
compound nanoparticle that is capable of production of bulk amount
at low cost semiconductor. In this work a copper iodine nanoparticles
were fabricate by exploding copper wires with different currents in
iodine solution. The produced samples were examined by XRD,
FTIR, SEM and TEM to characterize their properties. The XRD
proved the Nano-size for producer. The crystalline size increases
with increasing current. FTIR measurements show a peaks located at
638.92 for Cu-I stretch bond indicate on formation of copper iodide
compound and the peaks intensities increase with increasing current.
The SEM and TEM measurements show that the thin films have
nanostructures.

This work describes the weathering effects (UV-Irradiation, and
Rain) on the thermal conductivity of PS, PMMA, PS/PMMA blend
for packaging application. The samples were prepared by cast
method at different ratios (10, 30, 50, 70, and 90 %wt). It was seen
that the thermal conductivity of PMMA (0.145 W/m.K), and for
PS(0.095 W/m.K), which increases by PS ratio increase up to 50%
PS/PMMA blend then decreased that was attributed to increase in
miscibility of the blend involved. By UV-weathering, it was seen that
thermal conductivity for PMMA increased with UV-weathering up to
(30hr) then decreased, that was attributed to rigidity and defect
formation, respectively. For 30%PS/PMMA, there results showed
unsystematic decrease in thermal conductivity, which was attributed
to unsystematic degradation. By Rain-weathering, thermal
conductivity PS, PMMA, and 30 %PS, PMMA, it was seen
systematic decreased in PS and 30 % PS/PMMA thermal
conductivity; and systematic decrease in PMMA thermal
conductivity. That due to the water diffusion in the samples that
created some voids, bubbles, and results in decrease in thermal
conductivity. This result was attributed to the decrease in adhesive
between the components of polymer systems. The results suggested
that the samples involved could be used for packaging application.

BixSb2-xTe3 alloys with different ratios of Bi (x=0, 0.1, 0.3, 0.5,
and 2) have been prepared, Thin films of these alloys were prepared
using thermal evaporation method under vacuum of 10-5 Torr on
glass substrates at room temperature with different deposition rate
(0.16, 0.5, 0.83) nm/sec for thickness (100, 300, 500) respectively.
The X–ray diffraction measurements for BixSb2-xTe3 bulk and thin
films indicate the polycrystalline structure with a strong intensity of
peak of plane (015) preferred orientation with additional peaks,
(0015) and (1010 ) reflections planes, which is meaning that all films
present a very good texture along the (015) plane axis at different
intensities for each thin film for different thickness. AFM
measurements for the thin films of BixSb2-xTe3, show that the grain
size and the average surface roughness decreases with increasing of
the percentage Bi for different thickness.

For the first time Iron tungstate semiconductor oxides films
(FeWO4) was successfully synthesized simply by advanced
controlled chemical spray pyrolysis technique, via employed double
nozzle instead of single nozzle using tungstic acid and iron nitrate
solutions at three different compositions and spray separately at same
time on heated silicone (n-type) substrate at 600 °C, followed by
annealing treatment for one hour at 500 °C. The crystal structure,
microstructure and morphology properties of prepared films were
studied by X-ray diffraction analysis (XRD), electron Scanning
Electron Microscopy (SEM) and Atomic Force Microscopy (AFM)
respectively. According to characterization techniques, a material of
well-crystallized monoclinic phase FeWO4 films with spindle and
aggregated fine plates microstructures were obtained from using this
advance technique, with thickness about 500 nm. Such these
structures have been recognized as one of the most efficient
microstructures due to their large specific surface area especially in
gas sensor applications.

Poly methyl methacrylate PMMA polymer could be considered
the main material that used mostly in the recent years in denture base
fabrication. It commonly known by it is poor strength properties such
as low impact strength. The aim of the present research was to
enhance the performance of PMMA denture base through the
addition of two kind of nanoparticles (nano particles that selected
from artificial and natural sources). Nano -particles from both Al2O3
and crushed peanut Peel were used for comparing purposes.Various
weight fraction used in this study for both kinds of the additive (1%,
2% and 3%). Moreover, in this work a study and evaluation in impact
strength (I.S.) value were done before and after immersion. The new
prepared nanocomposite in three different liquids (mineral water,
natural lemon juice and Pepsi) immersed during three specific time
(10, 20 and 30 min), all tests completed at room temperature. It was
found that the impact strength value before immersion decreased
gradually during reinforcement with both type of nanoparticles
except when using 3% of Peanuts Peel nanoparticles. Also, it was
found after immersion pure PMMA in the three different liquid that
the value of I.S. decreased. When immersion the prepared sample
inside mineral water, it was noted that using Al2O3 as reinforcement
the determined value decrease with increasing the weight fraction
different from the Peanuts Peel. The obtained results showed that
immersion these samples in naturel lemon juice increased the value
of impact strength gradually with the time. I.S. value decreased while
immersion nanocomposite of Al2O3 with Pepsi, while an obvious
increase was clear with nanocomposite of Peanuts Peel with the
immersion time.

Tin oxide was deposited by using vacuum thermal method on
silicon wafer engraved by Computer Numerical Controlled (CNC)
Machine. The inscription was engraved by diamond-made brine.
Deep 0.05 mm in the form of concentric squares. Electrical results in
the dark were shown high value of forward current and the high
value of the detection factor from 6.42 before engraving to 10.41
after engraving. (I-V) characters in illumination with powers (50,
100, 150, 200, 250) mW/cm2 show Improved properties of the
detector, Especially at power (150, 200, 250) mW/cm2. Response
improved in rise time from 2.4 µs to 0.72 µs and time of inactivity
improved 515.2 µs to 44.2 µs. Sensitivity angle increased at zone
from 40o to 65o.

This study includes the direct influence of (single & multi)
dose of Cold Atmospheric Plasma (CAP) on the no. of platelets
for mice for different exposure time (15, 30, 60, and 120) sec. the
influence of CAP on mice was measured after 1, 2, 3, 7, and 14
day from exposure.
The results obtained in this study indicate that the effect of low
doses of CAP on platelets was stimulatory effect in the first few
hours from exposure (1day) but the high dose was inhibitory, It
was found that after two weeks of exposure that the number of
platelets became normal comparable to the control one, and this
indicates that plasma effect was removed after this period.

Fe, Co and Sb nanopowders were fruitfully prepared by
electrical wire explosion method in Double distilled and de-ionized
water (DDDW) media. The formation of iron, cobalt and antimony
(FeCoSb) alloy nanopowder was monitored by X-ray diffraction.
The x-ray diffraction pattern indicates that there are iron, cobalt and
antimony peaks. Optical properties of this alloy nanoparticles were
characterized by UV-Visible absorption spectra. The absorption peak
position is shifted to the lower wavelengths when the current
increases. That means the mean size of the nanoparticles controlled
by changing the magnitude of the current. The surface morphological
analysis is carried out by employing Scanning Electron Microscope
(SEM). Particles with varies size were observed also from the images
the some particles have uneven shapes with agglomerate and the
other have spherical shape. The exploding FeCoSb alloy wire plasma
parameters is study by optical emission spectroscopy. The emission
spectra of the plasma have been recorded and analyzed. The plasma
electron temperature (Te), was determined by Boltzmann plot, and
the electron density (ne), by Stark broadening for wire with diameter
0.3 mm and current of 75A in distilled water.

Hydrophobic silica aerogels were successfully preparation by an
ambient pressure drying method from sodium silicate (Na2SiO3) with
different pH values (5, 6, 7, 8, 9 and 10). In this study, acidic HCl
(1M), a basic NH4OH (1M) were selected as a catalyst to perform the
surface modification in a TMCS (trimethylchlorosilane) solution.
The surface chemical modification of the aerogels was assured by the
Fourier transform infrared (FTIR) spectroscopic studies. Other
physical properties, such as pore volume and pore size and specific
surface area were determined by Brunauer-Emmett- Teller (BET)
method. The effect of pH values on the bulk density of aerogel. The
sol–gel parameter pH value in the sol, have marked effects on the
physical properties of the silica aerogels produced by this technique.
The density and the hydrophobic tendency of the aerogels were
significantly influenced.

In this search, Ep/SiO2 at (3, 6, 9, 12 %) composites is prepared
by hand Lay-up method, to measure the change in the thermal
conductivity and Impact Strength of epoxy resin before and after
immersion in H2SO4 Solution with a 0.3N for 10 days. The results
before immersion decreases with the increase of the weight ratios of
the reinforcement material (SiO2), It changed from (82.6×10-2 to
38.7×10-2 W/m.°C) with change weight ratios from (3 to 12) %
respectively, but after immersion time in the chemical solution where
it was (65.6×10-2 W/m.°C) at the weight ratios (6 %) and became
(46.6 × 10-2 W/m.°C) after immersion in sulfuric acid. The results of
the Impact strength decreased by increasing the percentage weight
ratio, it changed from (1.48 to 0.87 kJ/m2) with change weight ratios
from (3 to 12) % respectively, but found an increase in the value of
Impact Strength after immersion in the chemical solution Where it
was (1.28 kJ/m2) at the weight ratio of 6 % and became (1.82 kJ/m2)
at the same weight ratio after immersion in sulfuric acid at normality
of 0.3 for 10 days.

The study of vegetative change of cities is one of the most
important studies related to human life because of its direct
correlation with the temporal conditions that occur. These include the
economic problems that force people to move and look for job
opportunities in the city, which leads to an increase in the population
density of cities, especially for cities with an important economic and
administrative location as in the capital city of Baghdad.
In this study, the effect of the increasing in population density was
analyzed on the urban planning of Baghdad city. The decreasing in
vegetation was due to the increasing of urban areas on the outskirts
of the city, which led to an increase in its area. Moreover, urban
cities increased the amount of randomization; this problem has not
good consequences on the environmental and health level and
attached services.
This study was carried out by finding the Normalized Difference
Vegetation Index (NDVI) of the study area through the using of two
satellite image from the Landsat7 satellite for two different dates
(2002 and 20017) after being uploaded from the US Geological
Survey site. The third and fourth bands were used to calculate the
Normalized Difference Vegetation Index (NDVI) by using Arc-GIS
Techniques.