Journal of Education and Scientific Studies

The optical properties of pure V₂O₅ films at different concentrations (0.1, 0.3, and 0.5
Mool) deposited on porous silicon substrates were investigated within the 300–900 nm
wavelength range using thermochemical spraying. The results showed increased absorbance and a higher absorption coefficient with increasing vanadium oxide concentration.
A decrease in transmittance and a reduction in the energy gap (2.51–2.63 eV) were observed with increasing concentration, as were increases in the extinction coefficient and
reflectivity. These improvements in optical properties suggest the potential use of these
films in optoelectronic devices and solar cells

This study analyzes the effect of a range of physical and structural variables on the performance of
perovskite solar cells based on FA₁₋ₓMAₓPbI₃ as the main absorber layer, using the SCAPS-1D simulation software. The study examined the effects of temperature, series resistance (Rs), parallel resistance
(Rsh), doping of the absorber layer, and the conformation, transmission, and reflection layers, as well as
the effect of absorber and conformation layer thickness (V₂O₅) on the fundamental photovoltaic characteristics: Voc, Jsc, FF, and efficiency (η). The results showed that increasing the temperature leads to a
significant decrease in Voc and η due to an increase in reverse saturation current and a narrowing of the
energy gap, while Jsc remained relatively constant. Increasing Rs also led to a deterioration in FF and
efficiency due to ohmic losses, while increasing Rsh helped reduce leakage currents and improve performance. The doping results showed that an optimal level of absorption layer doping achieves the highest
efficiency, while high doping resulted in increased recombination and decreased Jsc. V₂O₅ and ITO doping improved carrier extraction and reduced resistance, while the effect of CuO doping was limited. The
thickness effect demonstrated that increasing the absorption thickness increased Jsc and efficiency, while
increasing the alignment thickness slightly reduced performance. The study confirms that optimizing
cell efficiency requires a carefully considered balance between these factors.

This study demonstrates that heat treatment (sintering) at 1150°C is the most
critical factor in enhancing the mechanical and physical properties of nano-titanium
samples. This process successfully reduced porosity and increased relative density
by 30%, resulting in a significant improvement in fracture load and hardness compared to the brittle green compact. Furthermore, the addition of 30 wt% Molybdenum
enhanced the alloy’s hardness and promoted beta-phase stability, thereby achieving
a structural balance between hardness and toughness. Although Molybdenum increased the overall density and improved inter-particle bonding, the pure sintered
titanium exhibited superior resistance to maximum loads. These findings confirm
that the integration of thermal densification and alloying is key to optimizing the
long-term mechanical performance of advanced titanium alloys.

This study investigates the natural radioactivity levels in surface soil samples collected from the Jisr Diyala region,
south of Baghdad, and evaluates the associated radiological hazards, The results provide a necessary database for monitoring any variation in radioactive activity and optimal protection measures for the population. Gamma-ray spectrometry
using a high-purity germanium )HPGe( detector was employed to measure the activity concentrations of 238U, 232Th, and
40K. The mean activity concentrations were found to be 12.09 ± 0.85 Bq/kg, 11.26 ± 0.97 Bq/kg, and 220.10±13.33 Bq/
kg, respectively, with 40K contributing the highest activity .Radiological hazard parameters were calculated based on the
measured activities. The average radium equivalent activity )Ra
eq
( was 44.93 Bq/kg, while the absorbed gamma dose
rate in air was 21.47 nGy/h. The indoor and outdoor annual effective doses were estimated as 26.33 µSv/y and 105.31
µSv/y, respectively. Additional radiological indices, including the gamma activity index )I
γ
(, external hazard index )Hex(,
internal hazard index )Hin(, excess lifetime cancer risk )ELCR(, and annual gonadal dose equivalent )AGDE(, were all
found to be below the internationally recommended safety limits.The obtained results indicate that the natural radioactivity levels and associated radiological hazards in the studied soils are within the permissible limits recommended by
(UNSCEAR,2000(, and therefore do not pose any significant radiological risk to the population or the environment.

In this study, thin films of pure and aluminum-doped zinc selenide (ZnSe) were deposited on
glass substrates using pulsed laser deposition (PLD). The doping concentrations of aluminum were
(3%, 5%, and 7%). The deposition was carried out using a laser energy of (840) mJ at a frequency
of 7 Hz, with two different pulse counts: (100) and (500) pulses. The structural and optical band gap
properties of the pure and doped ZnSe films were investigated.
X-ray diffraction (XRD) analysis confirmed that all prepared films retained a cubic crystal structure. The main diffraction peaks were observed at 2θ angles of (27.7°, 45.3°, and 53.6°) , corresponding to the (111), (220), and (311) planes, respectively. An increase in peak intensity was noted
for the films deposited with (500) pulses, indicating improved crystallinity. However, a broadening
of the peaks (FWHM) was also observed with the higher number of pulses, suggesting a decrease
in crystallite size.
Atomic Force Microscopy (AFM) images showed a clear reduction in both surface roughness
and grain size as the number of pulses increased. Optically, the measurements revealed a slight decrease in the optical band gap with the increase in pulse number, suggesting that variations in pulse
count have a more pronounced effect on the structural properties than on the optical characteristics

In this research, we measured the concentrations of radioactive radon gas )222Rn( by selecting
10 samples of the most commonly used and popular local and imported fertilizers in the Iraqi markets. The closed chamber technique was used, which is not a common technique for measuring this
gas in fertilizers. Using the electronic radon detector (Rad-7), the lowest concentration of (222Rn(
was found to be (37.98±6.7 Bq.m-3) in sample (F.3) of Chinese origin, while the highest concentration of )222Rn) was (112.87±7.8 Bq.m-3( in sample )F.10( of Chinese origin. The overall average of
the measured samples was (84.953±8.2 Bq.m-3(, which is lower than the internationally permissible
limit set by ))ICRP(( for 2009, which is (200-300 Bq.m-3(. After performing several calculations to
determine the extent of contamination of these samples with )222Rn), the effective dose (AED) was
found to be (2.1235 mSv.y⁻¹), which is below the internationally accepted limit of (3-10 mSv.y⁻¹).
The annual incidence of cancer per million people (CPPP) for the studied samples was found to be
(3.8219 × 10⁻⁵), significantly lower than the limit set by (ICRP) of (170-230) per million people.
The surface emission )Eexh( of )222Rn)was also found to be (4.587 Bq.m⁻².h⁻¹), which is below the
internationally accepted limit.

Dans cette étude , SnO2 NPs powders are synthesized by the chemical bath approach
using SnCl4·5H2O. Compared to other approaches, SnO2 nanoparticles crystallize at a
lower temperature (200°C) and in a shorter duration (2 hours). Various advanced techniques are used to investigate the structural characteristics of SnO2 nanoparticles. include X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM),
and atomic force microscopy (AFM). The UV-visible spectrum and photoluminescence
(PL)spectrum were optical properties of SnO2 nanoparticles. XRD indicates that SnO2
nanoparticles are comprised of a pure rutile-type tetragonal phase, with an average particle size of 9.618 nm. FESEM pictures validate the dimensions of SnO2 nanoparticles
at the nanoscale, while AFM measurements indicate that the SnO2 particles are semispherical in shape. The energy band gap of SnO2 nanoparticles is seen in the UV-visible
spectrum. The photoluminescence spectra of SnO2 nanoparticles indicate that the near
band edge is 2.95eV.

Another trend in the effectiveness of radiotherapy is the application of radioactive nanoparticles; the biological effect of ionizing radiation may be increased by them effectively due to
their own unique properties. In this experiment, an effort was made to create a numeric simulator model using the linear quadratic equation of loss (LQ Model) to assess how varying
forms of nanoparticles affect the human cell response in radiation. The correlation between
the coefficients of radiosensitivity α and β) and concentration of nanoparticles was modeled in
Python 3.11 programming environment and the D50 and D10 doses as a measure of radioactivity were calculated. The findings revealed the gradual reduction in D50 and D10 increments
with a rise in particle dose, at the same time as cellular sensitivity on radiation sets in. It was
further revealed that the two, α and β, also rise with concentration, which is a sign that the
particles do offer direct and cumulative cellular damage. These findings pose an important use
of nanoparticles in enhancing the effectiveness of radiotherapy and favor their application as
a novel predictive measure in radiobiology particularly at lower doses. The research has also
paved the way to the formulation of directed treatment approaches using the characteristics of
particles and tumor biology which may eventually help in a better treatment outcome and the
minimization of the radiation damage to the normal tissue.

In this study, pure cadmium oxide (CdO) membranes inlaid with chromium ions in the
proportions of 0%, 2% and 4% were prepared using the thermochemical spraying method
and the effect of grafting on structural, morphological, optical and sensory properties towards NO₂ gas was studied.The X-ray diffraction results showed that all membranes possessed a polycrystalline cubic structure, with the average crystal size decreasing from 59.8
nm for the pure sample to 45.7 nm and 38.2 nm at grafting ratios of 2% and 4% respectively,
as shown by the FESEM images . The grain size decreased from 52.6 nm in the pure sample
to 41.8 nm and 34.5 nm with increased grafting, and was accompanied by a marked increase
in surface roughness. Optically, the power gap decreased from 2.63 eV for the pure sample
to 2.60 eV and 2.48 eV at 2% and 4% Cr, respectively, with a marked improvement in absorption. In gas sensing applications, the 4% Cr sample achieved the highest sensitivity
of about 50% at 200°C with response and retrieval times of 19.4 s and 24.6 s, respectively.
These results confirm that chromium CdO grafting within the 0–4% domain is an effective
strategy to improve the structural, optical and sensor performance of CdO membranes

This study focuses on the fabrication and characterization of nickel–vanadium alloys prepared by the powder metallurgy technique, aiming to investigate the influence of different vanadium contents (0–20 wt.%) on
the crystal structure, microstructure, mechanical properties, and mechanical wear behavior at 500 °C. X-ray diffraction (XRD) analysis confirmed that nickel preserved its face-centered cubic (FCC) structure in all compositions, while vanadium maintained its body-centered cubic (BCC) structure, indicating the stable coexistence
of both phases without the formation of unwanted phase transformations. The structural analysis revealed
that increasing the vanadium content led to a noticeable reduction in the crystallite size of the nickel matrix,
highlighting the effectiveness of vanadium in restricting grain growth and refining the microstructure. These
observations were further supported by scanning electron microscopy (SEM) results, which showed a gradual
decrease in grain size from approximately 120 nm for pure nickel to about 96 nm with the addition of 20 wt.%
vanadium. This behavior demonstrates the role of vanadium as an efficient grain refiner by stabilizing grain
boundaries and limiting their growth at elevated temperatures. The refined microstructure had a direct and positive impact on the mechanical properties of the alloys. The Vickers hardness values increased steadily from
148.6 HV for pure nickel to 178.2 HV at the highest vanadium content, which can be attributed to the increased
grain boundary density and enhanced resistance to dislocation movement. In addition, compressive strength
measurements showed a significant improvement with increasing vanadium content, rising from 420 MPa to
512 MPa. This enhancement confirms the strong correlation between grain size refinement and the improved
ability of the alloy to withstand plastic deformation under applied loads.The mechanical wear behavior of the
alloys was also evaluated, and the results demonstrated a continuous reduction in the wear rate with increasing
vanadium content. This improvement is mainly attributed to the increased hardness and the formation of a fine
and homogeneous microstructure, which effectively reduces material removal during sliding contact. Regarding true porosity, a slight increase was observed with higher vanadium additions; however, all porosity values
remained below 3%, indicating good densification and acceptable structural integrity of the prepared samples.
Keywords:Nickel alloys, Vanadium addition, Powder metallurgy, Microstructural refinement, Mechanical
properties, Wear behavior.

Iraq has strong solar resources, but it also faces a serious need for stable and reliable
electricity. Because of that, both grid-connected PV systems and stand-alone (off-grid)
systems can be practical solutions in different situations. The paper reviews several studies that used PVsyst in different Iraqi locations and with different system configurations. Most studies aimed to improve system performance by adjusting the tilt angle,
identifying where the main losses occur (such as temperature effects, dust/soiling, and
shading), or selecting PV technologies that better fit Iraq’s climate conditions. Overall,
the findings show that PVsyst can provide detailed predictions about system behavior,
expected energy production, and areas where the design can be improved. However, the
review also highlights some limitations. Many simulations assume fixed tilt angles, the
results are not always validated with real field measurements, and the economic analysis
is missing or not fully developed in several works. Even with these issues, the review
confirms that PVsyst remains a valuable predictive tool for planning solar projects. It
supports better system design and can help develop PV solutions that are efficient and
cost-effective in Iraq, and in other regions with similar climates.

This study aimed to determine the effect of low temperatures, ranging from 0°C to
-16°C, on the characteristics and performance of a 532 nm green DPSS laser. The results showed a decrease in threshold current with decreasing temperature, consistent with
the laser’s typical behavior. Temperature is the most important factor in determining the
performance and stability of the green DPSS laser. The results showed that increasing
temperatures leads to a significant deterioration in optical power, impaired stability, and a
decrease in optical conversion efficiency. Conversely, operating the laser at low and stable
temperatures showed a significant improvement in energy stability and an increase in optical conversion efficiency, reflecting improved laser output quality. These results indicate
that the adoption of precise thermal control systems and operation within low and stable
temperature ranges is essential to ensure the reliable operation and high performance of
DPSS laser systems, especially in scientific and industrial applications that require spectral stability and high operational efficiency.

The rapid growth in the diversity and number of vehicles has produced increasing environmental pollution, creating a serious threat to human safety and health. These circumstances
highlight the need for intelligent automated systems capable of accurately detecting vehicle
types to aid traffic management, improve public safety, and decrease congestion. This work introduces an effective model classification built on Continuous Wavelet Transform CWT scalogram representations combined with a Convolutional Neural Network CNN. The enhanced
time–frequency visual scalogram effectively describes non-stationary signals characterized by
time and spectral changes, authorizing suitable deep feature extraction. A global sound dataset
includes eight categories, and five of the most commonly used on the roads were selected for
training (each class 250 signals, except cars, the data contains only 229 audio files). The other
three, aircraft types, like a helicopter, were excluded. The data was divided 80 % training and
20 % testing. Image processing methods, like normalization, logarithmic transformation, and
denoising, were applied to improve feature classification. The CNN model performs strongly
and works with a balanced achievement, 97.31 % precision, 97.12% specificity, and an of
97.22 % F1-score. Class-wise analysis showed excellent performance across all vehicle types;
buses achieved optimal results with 100 %, while motorcycles and trucks had near-perfect
classification. The combination of enhanced CWT scalograms with CNN provides an accurate
system for intelligent traffic monitoring and management.

In this study, tantalum -doped zinc oxide to (ZnO-Ta) thin films were deposited glass
substrates on using a direct - Current (DC) magnetron sputtering system operating under
aragon atmosphere with a target substrate distance of (5cm) and a room temperature, the
films were prepared at sputtering Powers of (70, 80 W) with a deposition time of (5 min)
and a pressure (10-5 bar). The FE-SEM images revealed that the tantalum doped ZnO thin
films exhibit a well adhered nanostructure composed of nearly spherical grains within the
nanoscale range of approximately (17-66 nm) depending on the doping ratio and deposition conditions. The results also showed that increasing the Ta doping concentration leads
to a noticeable increase in grain size and surface roughness this observation is further
supported by cross-sectional analysis, indicating that higher tantalum doping results in
increased surface roughness furthermore, the antibacterial fast revealed that the samples
with rougher surfaces the and larger grain sizes exhibited the highest inhibition efficiency against both Gram- Positive (Staphylococcus aureus) and Gram-negative (Escherichia
coli) bacteria the results demonstrated that controlling the surface morphology through
Ta-doping in the key factor governing the antibacterial Performance. It was found that
increasing the tantalum doping ratio leads to higher surface roughness and enhanced bacterial inhibition efficiency which makes these films highly suitable for medical applications
as antibacterial materials.