Iraqi Journal of Physics

In this study, thin films of pure and aluminum (Al)-doped zinc oxide/polymethyl methacrylate (ZnO/PMMA) with two different amounts (5% and 7%) using the sol-gel and spin coating methods were created and then heated at two temperatures (450 and 750°C). Many characteristics were used to analyze the resulting samples, including X-ray diffraction (XRD), UV-visible, and infrared (IR) absorption spectroscopy. The X-ray diffraction analysis of the samples indicated that they formed a hexagonal structure of ZnO known as wurtzite, with a preferred direction labelled as (101). UV-visible analysis of the specimens\' optical characteristics has helped calculate the gap energy using the Tauc method. The energy value is 4.12 eV. The optical characteristics of the samples were analyzed by the Fourier Transform Infrared (FTIR), which shows the presence of absorption peaks attributed to the existence of the new phase that cannot be observed through the X-rays, which is a phase of spinel zinc aluminate (ZnAl2O4).

This study evaluated the relationship between the blood glucose level (BGL), maximal standardized uptake value (SUVmax), and 18F-FDG uptake in tissues at normal and tumour organs with positron emission tomography/computed tomography (PET/CT) examinations. On the morning of the procedure, finger-stick fasting blood glucose is routinely assessed. The study looked at the SUVmax in the liver and bone of 200 people with F-FDG PET/CT scans for tumors and healthy organs18. The study formed three groups of patients based on their serum glucose levels. The study retrospectively examined the relationship between glucose levels and standardized uptake values. The mean liver and bone SUVmax gradually decreased as blood glucose levels increased, starting at 160 mg/dl. All the groups whose blood glucose levels were between 100 and 160 mg/dl had a slight but significant increase in the uptake of 18F-fluorodeoxyglucose (FDG) in bones and livers compared to the group whose BGLs were all normal. The study concludes that following a BGL of 160 mg/dl, hyperglycemia progressively lowers the absorption of 18F-FDG by the liver and bones. Studies using FDG-PET are especially inaccurate when BGLs are high. Therefore, individuals undergoing FDG-PET examinations should fast and consider their BGLs.

The current study used satellite data and geographic information systems to detect changes in land use and land cover and also studied climate factors, temperature, and humidity in Amara, located in the southeast of Iraq, from 1990 to 2022. The study aimed to calculate the land use land cover (LULC) using satellite images from Landsat 5 TM, Landsat 8 OLI, and Landsat 9 OLI2, also from the Meteorological Service; temperature and humidity data were used to calculate the Temperature-Humidity Index (THI). Iraq was one of the nations most exposed to the altering climate due to global warming and its effects. There was an urgent need to research climate change and land use in Amara City as temperatures rose and the city experienced drought and a shortage of rainfall. The findings showed that the percentage of urban areas increased noticeably from 38.2 to 69.8 km2, the amount of vegetation increased slightly, and the barren areas were the highest. Low rainfall in the study area and high temperatures caused by global warming are two major variables affecting public safety. The main factors that affect the comfort of residents are temperature and humidity. The results of the climate suitability study also indicated that November and December are considered the most suitable months for the population, while the hottest and most unpleasant months were from the end of May to the beginning of September.

This study analyzes long-term trends in temporal data from 1980 to 2020 in Baghdad's city, spanning four decades, to assess the impacts of climate change on the environment and ecosystems. The National Aeronautics and Space Administration (NASA) provided us with data on wind, temperature, solar radiation, atmospheric pressure, precipitation, and humidity. The study used statistical analysis methods, such as trend analysis and ANOVA, to assess the differences between the decades of time. Linear regression models were employed to conduct trend analysis for each decade, assessing changes in climate parameters. Key findings indicated that the P-values were high. The findings demonstrated no statistically significant differences in the examined climate parameters during the decades. However, trend analysis of average monthly data over the four decades indicated that local climates have changed in recent years. The monthly analysis of six parameters indicated an increase in wind speed, temperature, and pressure, whereas solar radiation, humidity, and precipitation consistently decreased.

In this work, Ag and Ag@Cr nanoparticles were fabricated utilizing the plasma jet and chemical spray deposition approach to produce thin films of Ag and Ag@Cr. The optimal gas-detecting properties can be achieved by varying the ratios of Ag@Cr (4:6, 2:8, 3:7) ml and 10 ml Ag. XRD, transmission electron microscopy (TEM), and UV-Vis spectroscopy were used to characterize the Ag and Ag@Cr thin films. Additionally, an absorption peak appears at 422 nm for Ag, and the absorption peaks for Ag@Cr are at 408, 413, and 410 nm, with a polycrystalline character as seen from the XRD pattern. The gas NO₂ was used to check how sensitive, responsive, and quickly recoverable the Ag and Ag@Cr nanocomposite thin films are. According to the findings, at 150 °C, the optimal Ag@Cr ratio was 3:7 with 26% sensitivity. At 150 °C, pure silver's sensitivity was 32%, and it was concluded that chromium has low sensitivity. The results of the Hall effect test indicated that the material is p-type at all ratios.

Zinc oxide nanoparticles (ZnO NPs) were created using two different preparation methods: chemical precipitation and the green method using the leaves of Ficus carica extract. The nanoparticles were examined using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray Spectroscopy (EDX). Analytical techniques such as XRD were applied to verify the crystallinity of ZnO NPs as well as used to calculate the crystal size for the prepared samples. The XRD pattern exhibited a hexagonal structure, and the mean diameter of the crystal size for ZnO NPs prepared by chemical precipitation was 27.44 and 33nm for ZnO NPs prepared by the biological method. Nanoparticles of ZnO have a spherical shape, as examined by FE-SEM. The EDX test indicated the existence of peaks corresponding to zinc and oxygen. The surface properties, such as root mean square roughness (Rq) and average roughness (Ra) were examined by atomic force microscopy (AFM), where Rq and Ra were 35.8 and 29.3 nm, respectively. The ZnO NPs made using chemical precipitation and biological methods were studied with UV-visible spectroscopy (UV-Vis) to look at the absorption spectra, and it was found that the absorption spectrum increased with the green method.

This study used the green method to synthesise zinc oxide nanoparticles by microwave irradiation, using plant extracts of tea, coffee, and rosemary separately and Zn(NO₃)₂.6H₂O; this method is considered eco-friendly, rapid, and cost-effective. The structural properties of prepared materials were investigated with an X-ray diffractometer (XRD), atomic force microscope (AFM), Fourier transform infrared (FTIR) spectroscope, and field emission scanning electron microscope (FESEM). Energy Dispersive X-ray (EDX) analysis was used to prove the presence of ZnO NPs. The electrical charge of the surface of nanomaterials was measured by Zeta potential, where 20 mV is adequate for ensuring physical stability. The three green extracts (tea, coffee, and rosemary) were 21.9, 14.7, and 15.5 mV, respectively. The shapes of the zinc oxide nanoparticles were irregular and agglomerated, and the average particle size was 59.96, 24.63, and 24.59 nm for the three extracts. Infrared spectroscopy using the Fourier transform (FT-IR) methods verified the presence of C=O, N-O, and C-H bonds; these results confirm the high reducing and capping capacity of ZnO NPs via biomolecules found in the plant extract. A UV-Vis spectrometer was used to study the light properties, and the energy gap was found to be 3.31, 3.26, and 3.35 eV for the tea, coffee, and rosemary extracts, respectively. Finally, ZnO NPs were used to inhibit the activity of many kinds of fungi and bacteria, both gram-positive and gram-negative. Studies have demonstrated their ability to penetrate the bacterial cell wall and halt the bacterial activity.

In this research, iron oxide (Fe2O3) nanoparticles were doped with 5% mol of metallic material silver (Ag) and non-metallic material sulfur (S) by a wet impregnation process. Scanning electron microscopy (SEM) was used to determine the shape and arrangement of the crystals. UV-Vis spectroscopy was used to study the photocatalytic degradation of dye pollutants by measuring the absorbance spectra of the Ag/Fe2O3 and S/Fe₂O₃ nanoparticle samples. The objective of this study was to investigate the impact of pH on the photocatalytic activity of nanoparticles. The pH of a 5ppm solution of methylene blue (MB) dye was changed to 3 and 8 using hydrochloric acid (HCl) and sodium hydroxide (NaOH). In pH=8, Ag/Fe2O3 takes 240 min to reach nearly 93.35% degradation, while S/Fe2O3 achieves over 90% degradation in the first 60 min of the photocatalysis process. At pH=3, Ag/Fe2O3 achieves only 34.46 %, while S/Fe2O3 achieves 61.44% decomposition after 240 min. The pseudo-first-order kinetic model was found to be the best fit for the adsorption of MB by the two catalysts.

The study included preparing pure polyaniline (PANI) and treating it with sulfuric acid at various strengths while keeping the temperature at 27ºC. The morphology of the polymerization products was examined using a scanning electron microscope (SEM). The SEM images revealed a notable effect of how much acid is present on the formation of PANI. The investigation focused on the relationship of alternating electrical conductivity with temperature and frequency. The A.C. electrical conductivity was represented by the variable (s) and varied with frequency, which ranged from 1 kHz to 10 MHz. The value of s was found to be less than 1, and it decreased as the temperature increased. This observation implies a dominant hopping mechanism. The activation energy was measured within the temperature range of 303-423 K at a frequency of 10 kHz; the measured values ranged from 0.249 to 0.12 eV. The relative dielectric for PANI and the constant loss were determined. The data collected indicated that the actual dielectric constant exhibits a decrease with both frequency and temperature.

This research shows how to prepare polyvinyl alcohol (PVA) films with silver nanoparticles and how different amounts of these nanoparticles affect the films' properties. The silver nanoparticles (AgNPs), featuring a uniform spherical shape, were synthesised using the chemical reduction method. The concentration of AgNPs and the amount of the reducing agent were found to influence the structural and optical characteristics of the prepared films. Higher volumes of the reducing agent have resulted in the formation of larger silver nanoparticles. These factors affected the size of the silver nanoparticles and the specific absorption peak, which was between 420 and 435 nm, with the nanoparticles measuring between 20 and 32 nm in size. The UV-visible spectroscopy of PVA film samples with silver nanoparticles showed that the silver nanoparticles had a peak absorption in the 420-435 nm range. The FTIR spectroscopy showed that the silver nanoparticles do not chemically attach to the PVA structure, but instead, they fit into the matrix as small flaws. Still, they integrate into the matrix as structural imperfections. The present work aims to study the structural behaviour and particle size effect of Ag NPs dispersed in a polymer network and select the best conditions for synthesizing such nanostructures.

Over the past few years, there has been a significant focus on studying the synthesis and applications of metal nanoparticles. These tiny particles possess distinct properties that set them apart from bulk metals. The liquid for Cr:Se core-shell nanoparticles was made using the plasma jets method and turned into thin films that are 158.9 nm thick through chemical spray pyrolysis. The nano thin films were analyzed using X-ray diffraction (XRD), ultraviolet-visible spectroscopy, and transmission electron microscopy (TEM). This study looks at the structure and light properties of core-shell nanoparticles made with a chromium to selenium (Cr:Se) ratio of 6:4. The XRD patterns confirmed the crystalline nature of the nanoparticles for the polycrystalline ratio (6:4). When the best thin film, which is well-crystallized, is exposed to non-thermal plasma (dielectric barrier discharges (DBD)), the XRD shows important changes, suggesting it is becoming more crystalline. Tauc plots show that the direct bandgap energies change in a non-linear way, with a notable increase in energy from 2.77 to 3.88 eV. Transmission electron microscopy analysis highlights improved nanoparticle distribution and uniformity. These findings point out the importance of Cr:Se nanoparticles for advanced optoelectronic and sensing technologies, as well as various technological applications.

The study used optical emission spectroscopy to present the effect of changing doping ratios and laser energy on plasma parameters. Plasma spectra were acquired across energy levels by zinc oxide combined with nickel oxide (ZnOXNiO1-X) at x = 0.3, 0.5, and 0.7. The analysis of these airborne mixtures was carried out through spectroscopy. The electron temperature results indicated that the range for x=0.3 was 0.446-0.491 eV, for x=0.5 was 0.470-0.486 eV, and for x=0.7 it was 0.474-0.489 eV. Differences in electron temperatures between compositions can lead to new technological applications and comprehension of physical phenomena. It was found that when the proportion of doping was increased, the intensities of the spectral lines, electron temperature (Te), Debye number (ND), and Debye length (λD) increased. On the other hand, as the laser energy increased, the electron density (ne) and plasma frequency (fp) went down. At the same time, the emission lines from the doped material appeared more often in the mixed material. These results provide the best conditions for solar cell applications for zinc oxide elements combined with nickel oxide.

A hybrid organic-inorganic light-emitting diode (OI-LED) device was made by combining carbon nanoparticles (CNPs) that are 20 to 40 nm in size with layers of organic and inorganic semiconductors. This technique resulted in enhanced electroluminescence (EL) generation. The active layer comprised a composite of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl) diphenylamine))] (TFB) and tris(8-quinolinolato) aluminum(III) (Alq3). The device fabrication included spin-coating and phase-segregation techniques, yielding a thin-film structure with ITO/TFB/CNP/Alq3/Al configuration. The electroluminescent characteristics of the fabricated organic light-emitting diode were analysed by evaluating performance variations at different bias voltages (8, 9, and 10 V) and modifying the organic layers' deposition parameters at room temperature. Current-voltage curves exhibited a pronounced knee voltage of 0.6 V, significantly influenced by the applied bias voltage. This characteristic enabled the OI-LED to emit a broad light spectrum ranging from 300 to 800 nm. Electronic transitions associated with the surface states and sub-levels within the CNPs are responsible for the broad emission spectrum. The analysis of colour space, employing the Commission Internationale de l’Éclairage (CIE) standard, revealed that the device's correlated colour temperature (CCT) ranged from 1550 to 2550 K.

Cadmium selenide (CdSe) nanocrystals, modified with water-soluble L-cysteine and known as CdSe/Cys nanocrystals, were synthesized using L-cysteine as a stabilizing agent. This synthesis process ensured the formation of highly stable nanocrystals with desirable properties for various applications. The CdSe/Cys nanocrystals were carefully studied using advanced methods to understand their structure, composition, and optical features in detail. The peak that shows the preferred (111) orientation of L-cysteine-capped CdSe matches the usual core components, as indicated by the XRD pattern. On the other hand, the peaks at (220) and (311) are not as prominent. Photoluminescence (PL) spectroscopy was conducted to study the optical properties of the CdSe/Cys nanocrystals. The PL spectra's strong fluorescence emission showed these nanocrystals' excellent quantum efficiency. The emission peak was sharp and well-defined, highlighting the uniformity in size and composition of the synthesised nanocrystals. The study revealed the robust fluorescence of the spherical CdSe/Cys nanoparticles, with an average diameter of 2.3 nm. Modifying the surface of CdSe nanoparticles with cysteine improved their water solubility and biocompatibility.

This study aims to enhance the corrosion resistance of carbon steel (45 alloys) in saline water (3.5% NaCl) by applying a polymer nanocomposite coating. The nanocomposite was synthesized by integrating nickel oxide (NiO) and vanadium oxide (V₂O5) nanoparticles, produced via a green synthesis method using moringa extract, into a polyacrylonitrile (PA) matrix. The coating's performance was evaluated across various of temperatures: 293, 303, 313, and 323 K, achieving an inhibition efficiency of up to 89% at 303 K. The created nanocomposites were thoroughly tested using different methods, such as atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). AFM analysis revealed particle sizes of 44.5 nm for NiO and 54.47 nm for V₂O5, while TEM images indicated nonhomogeneous spherical morphologies. FT-IR and XRD showed that the nanoparticles were successfully added to the polymer, and TGA/DSC tests proved that the nanocomposites can withstand high temperatures. The results indicate that these nanocomposites could be very useful as strong corrosion protectors, improving the safety of carbon steel in harsh conditions.