Iraqi Journal of Physics

Abstract Article Info.
In this work, carboxymethyl cellulose/polyanionic cellulose (CMC
HV/PAC LV) films were prepared and exposed to different X-ray doses (0, 200,
400, 600 and 800 cGy). Absorption and transmission measurements of the
ultraviolet spectrum of the incident light were studied with a DU 800
spectrophotometer. Stress and strain were calculated by applying a tensile force to
the samples and increasing its amplitude until the sample breaks. Applying this
force to the samples increased the length of the samples. The absorption of CMC
HV/PAC LV films increased with increasing X-ray dose, and therefore, the
absorption coefficient increased with increasing X-ray dose. The results show that
the amount of spectral transmittance of the films decreased with increasing X-ray
dose, indicating that the opacity of the samples increased with increasing X-ray
dose. The characteristic absorption peaks are observed at 275 nm-1, 328 nm-1, 345
nm-1, 370 nm-1, and 470 nm-1, indicating molecular bonding. Increasing the X-ray
dose decreases the elastic modulus of the films, and the stress amplification factor
decreases with increasing strain ratio, indicating that X-ray photon irradiation leads
to a decrease in the elasticity of the films. The results of this research may be
useful in many fields, including industrial, medical or scientific research, as well as
in oil fields.

In this work, the properties of the photodetector were improved by using
carbon quantum dots (CQDs) and tris (8-hydroxyquinoline) aluminium (III) (Alq3)
polymer when deposited on glass and silicon substrates. CQDs were prepared using
an electrochemical method. Two methods of deposition were used; the first was drop
casting, and the other was spin coating. The structural, electrical, and optical
properties were studied. Measurements were made of the manufactured
photoconductive detector\'s current-voltage (I–V) properties, photocurrent gain,
response time, and quantum efficiency, responsivity. The constructed detector\'s
performance was measured without light and using a 250-watt tungsten lamp, whose
wavelength range was between 500 and 800 nm. The results showed that the best
photodetector was when carbon quantum dots were used with Alq3 deposited on a
silicon substrate using the drop-casting method (CQD:Alq3/Si). It was observed that
the best gain, fastest rise, fall, and response times were 7.97, 0.98, 1.1, and 0.34 s,
respectively.

The current study uses the relativistic mean field approach to investigate the nuclear structure of selected even-even neutron-rich nuclei spanning from the stability line to the neutron drip line. Specifically, the nuclei studied include 16–28O, 30–42Si, 48–60Ca, 56–68Ni, 88–100Kr, 96–122Ru, 140–152Ba, 142–154Sm, and 150–162Er. The relativistic Hartree-Bogoliubov (RHB) method was applied, incorporating effective density-dependent point coupling (DD-PC) and density-dependent meson exchange (DD-ME) interactions. The impact of these interactions was demonstrated through the calculation of various nuclear structure properties, including binding energy (BE), kinetic energy (KE), pairing energy (PE), root mean square (rms) charge radius, two-neutron separation energy (S2n), mass densities (ρm), and triaxial deformation. The calculated results were compared with the available experimental data. It is clear that the RMF approach, particularly with the DD-ME2 and DD-PC1 effective interactions, proved to be a valuable tool for studying nuclear properties near the drip lines and away from stability, providing insights into the behavior of exotic or halo nuclei.

Polyaniline (PANI) and manganese dioxide (MnO2) doped with nickel
oxide (NiO) nanocomposite have emerged as promising materials for gas sensing
applications due to their high conductivity and surface area. This study improves
the synthesized PANI/MnO2:NiO nanocomposites\' sensitivity towards NO2 gas.
Atomic force microscopy (AFM), Fourier transfer infrared (FTIR), scanning
electron microscopy (SEM), energy-dispersive X-ray analysis (EDS), and X-ray
diffraction (XRD) were used to analyze the produced nanocomposites. More
precise methods were investigated to identify problems associated with oxidation,
corrosion and sensor activity, such as increasing the amount of added nickel oxide,
changing the structure of nanocomposites, and regulating the working temperature
and humidity. Based on the results of this study, it is critical to comprehend how
sensitive nanomaterials are to NO2 gas because exposure to this pollutant can
negatively impact the environment and human health. Strategies to reduce its
effects and improve industrial and environmental safety can be devised based on
how nanomaterials react to nitrogen dioxide gas. We also examine antioxidants and
PANI/MnO2:NiO nanocomposites for their anti-corrosion properties to guarantee
long-term stability with the sensor\'s conductivity. Strong antioxidant and
corrosion-resistant substances should be added to the sensor to extend its lifespan
and maintain its performance under challenging operating conditions. Integrating
these sensitive nanomaterials into gas-sensing devices can significantly improve
environmental monitoring and industrial safety protocols, ultimately contributing to better air quality management and public health protection.

Hybrid graphene (GR)/ polyaniline (PANI) based composites incorporating
zinc sulfide (ZnS) nanoparticles were synthesized using the drop-casting method. The
weight percentage of ZnS was varied from 0.01 to 0.05%. The optical, structural, and
morphological characteristics of the nanocomposite were examined utilizing X-ray
diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopic
(AFM), and UV-Vis spectroscopy. The qualities and dimensions of the GR, PANI,
and ZnS NPs and nanoparticle morphology resulting from the nanocomposite process
were examined. Utilizing energy dispersive energy X-ray dispersive (EDX), the
weight percentage of each element can be verified. The widening sharp peaks in the
XRD patterns suggested the creation of a nanocrystalline phase of ZnS with a
crystallite size of less than 50 nm. SEM demonstrated the interaction between ZnS
nanoparticles and graphene/polyaniline. Surface topography examination using AFM
shows that ZnS NPs may be effectively dispersed on top of GR/PANI structures. The
ultraviolet-visible absorption spectrum (UV-Vis) showed a small absorption peak at
the wavelength of 459.34nm and a broad absorption peak at 652nm.

Assessment of wind resources is an important issue in the wind industry. This
study aims to assess wind energy in southern Iraq, especially in the Ali Al-Gharbi
region. It includes field data for the wind speed at two altitudes (30 and 50m) in 2017,
using the Weibull Distribution, wind power density and wind energy density
equations. The probability density distribution of mean wind speed and daily,
monthly, and seasonal wind speeds were calculated. The monthly mean wind power
density and wind energy density at heights (30 and 50m) were estimated. The suitable
wind turbine in this study area was the Unison U50. The capacity factor was assessed.
The results showed a northwesterly prevailing wind speed direction in the study area.
Mean wind speed increases during day hours and decreases during night hours
throughout the four seasons. The highest monthly mean wind speed is in May and
June. The highest seasonal mean wind speed is in spring and summer, while the
lowest is in winter and autumn. The highest monthly mean of wind power density and
wind energy density were in June, while the lowest values were in February. The
highest monthly values of wind power, wind energy, and capacity factor were
(5851.11kW, 4212802.15kW.h, 78%) respectively, while the lowest monthly values
were (1080.43kW, 777913.34kW.h, 14%), respectively.

Polythiophene (PTh) is very interesting in various applications due to its
unique electrical, mechanical and structural properties. In this work, PTh was
synthesized using the oxidation method by employing ferric chloride (FeCl3) as an
oxidizing agent, Then the nanocomposite polythiophene: Multi-walled carbon
nanotubes: Tin (IV) oxide (PTh/MWCNT/SnO2) was prepared by adding constant
weight ratio of MWCNT (0.7g) and different weight ratios of SnO2 (0.1, and 0.5g)
using the oxidation method. The FE-SEM images of the pure PTh and the
nanocomposite showed an apparent change in the morphological composition of
the surface. The X-ray diffraction (XRD) pattern of PTh/ MWCNT/SnO2
nanocomposites shows clear peaks for SnO2, while there are broad peaks for
MWCNT. As for the polymer, its behaviour is random. The morphology of these
nanocomposites shows that the nanotubes were not well aligned and were
randomly entangled. The Fourier transformer infrared (FT-IR) spectra of the pure
and nanocomposite samples prepared by chemical method in the range of 450-4000
cm-1wave number are recognized as the chemical pledges (bonds) and functional
groups in the compound. The band gap energy decreased from 3.53 to 2.78 and
2.97 when SnO2 was added. The sensitivity of the two nanocomposites shows a
good enhancement of 14.6% and 62% at the temperature 150C as gas sensor.

Evapotranspiration is considered an essential element for the
stability of the ecosystem due to its importance in many aspects,
including the water cycle, which is an important source of fresh water for
humans, animals and plants. It also has great importance in influencing
climate, temperatures and regulating weather. It also enters into the
design of irrigation networks for crops and knowing their water needs to
prevent drought and desertification. The Penman-Monteith method is
effective and accurate for calculating daily reference evapotranspiration
and has been adopted by the Food and Agriculture Organization (FAO) as
a standard method. This study aims to calculate the variation in
evapotranspiration rates in Iraq using the Penman-Monteith method over
the past thirteen years (2008-2020) in five equal periods (2008, 2011,
2014, 2017, and 2022). This study showed that the total rates of
evapotranspiration are decreasing and these values reached their peak in
2008 and then decreased significantly in subsequent years. The reason for
this decrease is the decrease in wind speed and the increase in relative
humidity. It was found that evapotranspiration rates in the central and
southern governorates are higher than in the northern governorates.
However, there are deviations in the rates for some stations, such as in
2020, which witnessed a general decrease in evapotranspiration rates,
with the exception of some stations that recorded an increase. For
example, Khanaqin station recorded the highest increase in
evapotranspiration rates, which amounted to 23.6%. The reason for this
increase is the increase in temperatures by 5.2% and the decrease in
relative humidity by -6.5%.

This work evaluates a new titanium dioxide/silicon nitride (TiO2/Si3N4)
catalyst prepared by the deposition of thin films of Si3N4 and TiO2 nanostructures
on glass using a lab-made closed-field unbalanced DC reactive magnetron
sputtering technique. A highly pure silicon sheet and titanium sheet were used as a
sputtering target, and a gas mixture of (Ar: N2) and (Ar∶O2) with mixing ratios of
(50:50) for each was used to prepare TiO2/Si3N4 sample, respectively. This sample
has been heat treated. The structure and morphology of the catalyst were
determined by X-ray diffraction (XRD), Field-Emission Scanning Electron
Microscopy (FE-SEM), Energy Dispersive X-ray (EDX) Spectroscopy, and
Fourier transform infrared (FTIR) spectroscopy. The resultant nanocomposite
sample was polycrystalline, and there were no impurities in the investigated
nanocomposite, as revealed by XRD analysis. The absorption edge was found to be
at 420 nm, as revealed by UV-visible spectroscopy, and the study of the optical
properties also showed that the absorption edge of TiO2/Si3N4 was shifted towards
the low energy region (redshift) relative to TiO2. The results obtained from the
photodegradation of organic pollutants under a Xenon lamp indicate that
TiO2/Si3N4 nanocomposite photocatalytic activity is significantly more effective
than TiO2 nanophotocatalyst.

This paper investigates the proton capture reactions 7Be(p,γ)8B,
12C(p,γ)13N, 14N(p,γ)15O, and 15N(p,γ)12C in the proton-proton (p-p) chain and
Carbon-Nitrogen-Oxygen cycle (CNO), which are essential for comprehending the
development of main sequence stars in the initial stages of spiral and elliptical
galaxy formation. This study investigates proton capture reactions in spiral and
elliptical galaxies. The excitation functions were summarized, which describe the
energy dependence of the nuclear reaction cross-sections, to analyze the (p,γ)
interaction cross-sections of 7Be(p,γ)8B, 12C(p,γ)13N, 14N(p,γ)15O, and 15N(p, γ)12C,
in the p-p series and CNO cycle with energy up to 8 MeV. In this work, the
theoretical values from the ENDF/B-VII library were compared with the estimated
database of proton capture cross-sections in hydrogen-burning stellar objects from
CSC-GM and TALYS. Cross-sections can be calculated at low energies within the
p-p chain and CNO cycle. Therefore, we were able to calculate the proton capture
cross-sections of four of the investigated nuclear reactions, 7Be(p,γ)8B, 12C(p,γ)13N,
14N(p,γ)15O, and 15N(p,γ)12C, which are part of the p-p chain and CNO cycle in
stellar nucleosynthesis in galaxies.

A simulated perovskite solar cell based on a P3HT/MAPbI3/C60 structure
is examined to achieve 30% PCE using SCAPS-1D software. Several aspects of A
simulated perovskite solar cell based on a P3HT/MAPbI3/C60 structure are
examined to achieve 30% PCE using SCAPS-1D software. Several aspects of the
perovskite layer were evaluated, including the perovskite layer thickness, CB and
VB effective density of state, band gap, and electron affinity. These factors greatly
influence the device's performance. The best device based on the best-examined
parameter has exhibited a PCE of 32.1% correlated with FF of 84.8%, VOC of
1.23V and JSC of 30.77 mA.cm-2. Such a result is promising towards achieving high
PCE for perovskite-based solar cells by optimizing several factors, including active
layer thickness, energy band gap, electron affinity, and effective state density for
CB and VB. However, the preparation conditions and other factors may render this
result in the experimentally produced solar cells. A low effective DOS of (1x1016m-3) is desired for both CB and VB to achieve high solar cell performance.

Gas sensors are essential for detecting noxious gases that have a
detrimental effect on people's health and welfare. Carbon quantum dots (CQDs) are
the fundamental component of gas detectors. CQDs and graphene (Gr) were
prepared using the electrochemical method. The gas sensitivity of these materials
was evaluated at different temperatures (150, 200, 250 C) to assess their
effectiveness. Subsequently, experiments were conducted at different temperatures
to ascertain that the combination of CQDs and Gr, with various percentages of Gr
and CQDs, exhibited superior gas sensitization properties compared to CQDs
alone. This was evaluated based on criteria such as sensitivity, recovery time, and
reaction time. Interestingly, the combination was highly responsive. The quantum
dots on glass substrates could detect NO2 gas at the temperatures mentioned above.
Experimental evidence showed that the gas sensor can only detect graphene at low
temperatures. Measurements indicate that the resistance diminishes with various
graphene concentrations, accompanied by a decrease in both Response and Recovery times.

Zinc cobalt ferrite (ZnCoFe2O4) and zinc ferrite (ZnFe2O4) were prepared using the sol-gel synthesis. Composite materials, PAN@CoFe2O4 and PAN@ZnCoFe2O4, were created by combining polyacrylonitrile (PAN) polymer with ZnCoFe2O4 and ZnFe2O4. Electrospinning was used to apply thin coatings onto glass and p-Si wafers. The synthesized fibre for both pure PAN polymers and their ferrite-based composites was illustrated in Field Emission Scanning Electron Microscopy (FESEM) images. The X-ray diffraction (XRD) analysis reveals that the PAN polymer exhibits a prominent peak at a precise angle of 29. 3345°.The size of this peak remains constant in PAN composites containing ZnCoFe2O4 and CoFe2O4. Fourier transformer infrared (FTIR) shows that absorptions have stretching vibrations between metal and oxygen. Nanofiber composites display nonohmic characteristics, as evidenced by current-voltage (I-V) tests. PAN nanofibers display conductive properties, whilst their ferrite composites demonstrate
rectification behaviour at room temperature when subjected to a low applied field.
For PAN NFs, there is no effect when relative humidity percentage increases and decreases, but with adding ferrite materials PAN@ZnFe2O4 and PAN@ZnCoFe2O4 where, there is a significant change in resistance when humidity increases and decreases.