Iraqi Journal of Physics

In this study, one-dimensional non-linear Klein-Gordon equations are solved by applying the integral transform known as the Rohit transform method. The approximate solutions of one-dimensional non-linear Klein- Gordon equations are obtained by combining the Adomian polynomials with the Rohit transform. To show the effectiveness and performance of the Rohit transform method, five one-dimensional non-linear Klein- Gordon type equations are considered and solved. The graphs of the solutions obtained are plotted to indicate the generality and clarity of the proposed method. It can be easily verified that the proposed method yielded the results that satisfy their corresponding non-linear Klein-Gordon equations. The integral Rohit transform combined with Adomian polynomials brought progressive methodologies that offer new insights on the problems (i.e., one-dimensional non-linear Klein-Gordon) examined in the paper, distinguishing itself from existing methods and doubtlessly beginning up new research instructions. Moreover, it reduces the complexity that occurs when non-linear Klein-Gordon are solved by other methods available in the literature. It provided precise results for the specific problems discussed in the paper, surpassing the capabilities of different methods in terms of decision, constancy, or robustness to noise and disturbances.

Using a 940nm diode laser or traditional methods, second-stage implant exposure involves removing soft tissue above the dental implant to expose the implant fixture and complete the implant procedure. This study included twenty-three patients (43.5% of whom were males, and the female percentage was 56.5%), aged between 18 and 70 years, who had at least two implants (3-6 months after implant insertion). Implant exposure was performed in case 1, using the traditional methods of puncture, flap, or incision, and in case 2, using a 940 nm diode laser. The study took place in Baghdad, Iraq. The results showed that the average pain in the laser group was 1.48, which was less than the average pain in the traditional group, which was 3.70. The pain scores that patients immediately reported for the laser cases were between 0 and 3, while the pain scores for the conventional cases were higher, ranging from 2 to 6. This was statistically significant in favour of the laser cases. All patients using the traditional method required infiltration anaesthesia, while 20 patients were satisfied with topical anaesthesia in the diode laser cases; this was statistically significant, favouring the laser method. This study revealed that the 940 nm diode laser is more efficient than the conventional method regarding the patient's perception of pain and the need for infiltration anaesthesia.

The aim of this study was to produce flexible films by combining polylactic acid (PLA) and poly(ε-caprolactone) (PCL), and enhance their strength by reinforcing them with different weight percentages (0.75, 1.5, and 2.25%) of zirconium oxide (ZrO2) nanoparticles (NPs) using a solvent casting process. The physical and antibacterial properties of the films were analysed to determine their suitability for use in food packaging. X-ray diffraction (XRD) patterns of the PLA/PCL films containing 2.25% by weight ZrO2 nanoparticles have a peak at an angle of 2θ = 17.18°, accompanied by smaller peaks. This confirms that these thin films have a semi-crystalline structure and that the molecules in the thin films are well dispersed. Scanning electron microscopy (SEM) analysis of the film surfaces reveals that the pure PLA/PCL films exhibit a smooth surface, while the PLA/PCL/ZrO2NPs films have a rough surface. The thermal behaviour of the blends through differential scanning calorimetry (DSC) showed fluctuations due to variations in the reinforcement ratio, resulting in changes in the glass transition and melting temperatures. These oscillations indicate changes in the level of crystallinity. ZnO2 has antibacterial properties that promote growth inhibition, making these films more effective in food packaging.

The production and use of nanometallic elements, such as gold, have received a lot of attention lately due to their distinctive features and wide range of uses. Most of these studies have employed the Turkevich approach. This research employed the Turkevich technique to produce gold nanoparticles (AuNPs). AuNPs and bromelain-loaded AuNPs were characterized using a variety of methods, including ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and zeta potential (ZP) measurements. The UV-Vis spectra of bromelain, AuNPs, and AuNPs-bromelain each had a peak at 276, 534, and 550 nm wavelengths, respectively. The FE-SEM and TEM studies revealed the presence of spherical particles with a smooth surface. The diameters of the AuNPs ranged from 49.32 to 77.29 nm; the diameters of the bromelain-AuNPs ranged from 46.39 to 75.66 nm, as determined by the FE-SEM analysis. The TEM analysis indicated that the particles' sizes ranged from 7.40 to 15 nm for AuNPs and 14.51 nm for AuNPs-bromelain. The XRD patterns revealed numerous diffraction peaks, indicating the crystal structure of the synthesized nanoparticles. FTIR spectrometry was employed to identify the functional groups in the synthesized nanoparticles. Zeta potential (ZP) measurements revealed that AuNPs had a zeta potential value of +0.1±0.4, and the zeta potential value for AuNPs-bromelain was +1.2±3.0 mV.

In this research, the dynamics of double-head streamer discharge initiation, propagation, interaction and breakdown in the air under different pressure values were presented. The double-head streamer discharge dynamics were analysed within a plane-to-plane electrode configuration. That was done through many aspects proposed, such as electron density, electric field, space charge density and streamer propagation speed. The simulation performed using ‘COMSOL Multiphysics’ is based on the finite element method and was carried out with the fluid model. The fluid model describes the movement of particle concentrations using partial differential equations (PDEs) together with Poisson’s equation; Poisson's equation and charge concentrations determine the electric field distribution in space. According to the results, as the pressure increased from (1, 2 and 3atm), the evolution time of the streamer increased from (0.563 to16.29ns) with the same breakdown voltage of 19kV. This means that the double-head streamer discharge developed faster with the decrease in pressure.

Astronomical radio observations from a small radio telescope suffer from various types of noise. Hence, astronomers continuously search for new techniques to eliminate or reduce such noise and obtain more accurate results. This research investigates the impact of implementing the Savitzky-Golay filter on enhancing radio observation signals retrieved from the Baghdad University radio telescope (BURT). Observations from BURT were carried out for different Galactic coordinates, and then a MATLAB code was written and used to implement the Savitzky-Golay filter for the collected data. This process provides an assessment of the ability of the filter to reduce noise and improve the quality of the signal. The results of this research clearly showed that applying the Savitzky-Golay filter reduces the noise and enhances the signal of astronomical radio observations. However, the filter should be used appropriately to preserve the original features of the signal. In conclusion, the filter is considered an efficient tool for enhancing the radio signal by reducing the noise and smoothing the signal. Therefore, the filter provides a substantial contribution and improvement to the field of radio astronomy.

Polypyrrole (PPy) nanocomposites were prepared using chemical oxidation and were combined with manganese oxide (MnO2) nanoparticles. The PPY-MnO2 nanocomposite was synthesized by integrating PPy nanofibers with varying volume ratio percentages of MnO2 dopant (10, 30, and 50% vol. ratio). The structural features of the PPy and PPy-MnO2 nanocomposite were investigated using X-ray diffraction (XRD). Fourier transfor infrared (FTIR) spectroscopy was used to demonstrate the molecular structures of primary materials and the final product of PPy, MnO2, and PPy- MnO2 nanocomposites. Field Emission Scanning Electron Microscopy (FESEM) showed that the morphology of PPy consisted of a network of nanofibers. Increasing the volume ratios of manganese oxide added to the PPY nanofiber led to the increase of manganese oxide nanoparticles on the surface of the PPY nanofiber network. This resulted in a noticeable alteration in the structure of the nanocomposite. It has been observed that the nanocomposites demonstrate a significant level of pseudocapacitive activity. The highest capacitance of 236 F/g was observed when pure PPy was doped with 30% MnO2 compared to 125 F/g of the pure PPy.

Theoretically, the AlxGa1-xAs/GaAs superlattice is studied as a function of optical energy with and without bias. The transfer matrix approach has determined the transmission coefficient and resonant tunnelling current density. The number of barriers is estimated at N = 3, and the concentration ratio (the mole fraction value) x at 0.1, 0.2, and 0.3 is fixed. The number of cells in the well is established at (ncw) = 5, while the number of barrier cells (ncb) is changed from 1 to 5 for both biases. This study shows that the change in the number of barrier cells plays a crucial role in the tunnelling of charge carriers and the transmission probability of charge carriers through the depletion regions. Thus, changing the current density is based on the purpose to be applied. In addition, the values of current density at the reverse bias are higher than that in the forward bias, which is explained by the bias controlling the energy levels of the superlattice. It is worth noting that there are many practical applications in which this system can be used, including solar cells, detectors, and light-emitting diodes.

In this study, a straightforward, expeditious, and environmentally friendly approach to synthesize copper oxide nanoparticles (CuONPs) utilizing an aqueous extract of Rhazya Stricta (R. stricta) leaves was employed. The CuONPs underwent various analytical techniques for characterization, including X-ray diffractometer (XRD), field emission scan electron microscope (FESEM), energy dispersive X-ray (EDX) analyses, UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and zeta potential. The XRD analysis authenticated the monoclinic crystal nature, revealing an average crystallite size of 15.6 nm. FESEM images depicted semi-spherical and cubic shapes, with particle sizes ranging from 56.64 to 86.95 nm. The formation of CuONPs was initially confirmed by the observable change in color, attributed to the excitation of surface Plasmon resonance at 280 nm in the UV-Vis spectra. FTIR analysis affirmed the presence of functional groups in the R. Stricta leaves extract, serving as both reducing and stabilizing agents, facilitating the formation of CuONPs. Zeta potential measurements indicated substantial stability with a value of -49.7 mV. The biosynthesized CuONPs were further evaluated for their antibacterial properties against Klebsiella Pneumoniae (K. pneumoniae) and Staphylococcus aureus (S. aureus), yielding inhibition zones of 21 mm and 30 mm, respectively. Additionally, the cytotoxicity assessment of CuONPs against A549 cell lines revealed higher cytotoxicity of 81.47 ± 1.517 at a CuONP concentration of 100 μg/ml. This work is the first attempt at R. stricta-facilitated synthesis of CuONPs as antibacterial and anticancer agents. It can subsequently be exploited as a potential candidate for these agents and might be utilized further in vivo studies.

The research investigated the effect of magnetic mirror configuration on the properties of plasma formed in a dielectric barrier discharge (DBD) actuator under atmospheric pressure. The discharge was formed when a high alternating voltage of 22 kV at a frequency of 9 kHz was applied between the electrodes under atmospheric pressure. The magnetic mirror was created when two permanent magnets were placed behind the electrodes. Plasma emission spectra were detected using a photoemission spectrometer at different horizontal distances (D) between the dielectric and the actuator, ranging from 0 to 5 cm. The effect of the magnetic mirror on the plasma properties at different horizontal distances was studied. The results indicated that the value of electron temperature increases with an increase in the horizontal distance at a smaller rate in the presence of the magnetic mirror configuration. The decrease in the surface area of the electrode led to a significant increase in the electron number density in the presence of the magnetic field. The magnetic mirror affected the value of all the plasma properties studied. At the same time, there was no effect on the behaviour of plasma properties in the presence of magnetic mirror configurations.

Magnesium Phthalocyanine (MgPc) was deposited on a glass substrate by pulsed laser deposition (PLD) using Q-Switching Nd:YAG laser with wavelength 1064 nm, repetition rate 6 Hz, at room temperature (300K) and different annealing temperatures (373, 473, and 573) K under vacuum condition of 10-3 torr. All films were annealed for one hour to attain crystallinity. X-ray diffraction (XRD) of MgPc powder indicated that MgPc crystallizes in polycrystalline with a monoclinic structure. While comparing the MgPc films, it was observed that the intensity of the characteristic peak increases with temperature, and the crystallization exhibited a monoclinic structure typical of the β-form. The Miller indices, hkl, values for each diffraction peak in the XRD spectrum were calculated. The characteristic peak of Phthalocyanine (MgPc) was found at 2θ value 6.9137ᵒ with the hkl value of (100) for both MgPc powder and deposited thin films. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) analyses, and atomic force microscopic (AFM) indicated that crystallinity improved and surface morphology was enhanced with the rise in annealing temperature and showed uniform-sized grains. They also assisted in identifying the optimal parameters that yielded the best structural properties for the thin film. The optical properties of MgPc thin film showed two absorption bands. The MgPc thin films exhibit transport and onset direct energy gaps (Eg) for all samples. Additionally, the absorption coefficient (α) was calculated using Lambert Law, revealing a slight dependence on the annealing temperature. FT-IR) spectra for (MgPc) and (H2Pc) were determined.

The expansion of building blocks at the expense of agricultural land is one of the main problems causing climate change within the urban area of a city. The research came to determine these indicators, as a study was conducted on the expansion of the building blocks in three municipalities in the city of Baghdad for a period of four decades extended in the form of time cycles for the period (1981-2021) and using ArcMap GIS 10.7 technology. Then, the impact of this expansion on temperature rates was evaluated, as they are the most important climatic elements due to their significant effect on the rest of the elements. The results showed a clear, direct relationship between the increase in urban expansion rates and the corresponding rise in temperature rates, which results in urban heat islands. The results for the last time cycle showed high expansion rates for the municipalities of Al-Kadhimiya, Al-Shaala, and New Baghdad (62.2, 82.4, and 92.1), respectively, and were offset by high-temperature rates (25.2, 25.49, and 25.67) for the same municipalities, respectively, as the highest rates were recorded in the New Baghdad municipality, followed by the municipality of Al-Shaala, in second place, then the municipality of Al-Kadhimiya, with the lowest rates due to its location on the Tigris River.

Electric energy production by fuel burning produces dangerous pollutants. The photovoltaic solar cell is a suitable alternative. For thin film solar cells, efficiency improvement should be carried out through continued development of their characteristics. The homojunction solar cell has reached its optimum. In the present work, a relationship between optical band gap and solar cell efficiency of heterojunctions has been established. Suitable band gaps of a pair of heterojunctions are required to get maximum efficiency for an appropriate frequency of solar radiation. The efficiency of a couple of extrinsic semiconductors can be calculated theoretically. An optimum band gap of a pair of heterojunctions with the highest efficiency may be found by this process. The efficiency of a few heterojunctions has been calculated using reported data. The results show that efficiency is increased with optical band gaps, and type-I is more efficient than type-II heterojunctions. The work may help to improve the solar cell efficiency.