Journal of Applied Sciences and Nanotechnology

Graphene-ZnO nanohybrid thin films were prepared by spray pyrolysis technique at 350 °C. Different graphene nanoplate concentrations of 0.1, 0.2, 0.3, 0.4, and 0.5 wt.% were used to deposit films on quartz substrates. The Structural and optical properties of the nanohybrid films have been investigated. X-ray diffraction XRD results show that the films have a hexagonal wurtzite polycrystalline structure and no secondary phases were observed. The structural parameters of crystallite size, dislocation density, and microstrain have indicated that the addition of graphene has a strong effect on the microstructure of zinc oxide films. Surface morphological analysis of the ZnO-graphene films reveals that the graphene content effectively modifies the morphologies and grain growth of the ZnO microstructure. It was also found from the optical properties that the maximum energy gap for pure ZnO films was 3.4 eV which decreases to 2.7 eV as the concentration of graphene increases to 0.5 wt.%. Results confirmed that graphene can be used as an efficient modifier for band gap engineering and the microstructure of ZnO thin films for enhanced photovoltaic applications.

One of the recommended platforms for waveguide generation in the infrared region is silicon-on-sapphire (SOS). This paper proposes a modal of the optical waveguide of silicon on a sapphire from λ=2-5 μm, using FEM (finite-element method) solver simulation performed by FDTD [finite-different-time-domain]. The waveguide is directly based on the refractive index difference between the wave's guideline regions and surrounding media (cladding). The use of FEM to analyze a single waveguide mode of SOS at a certain size within multiple wavelengths is a unique aspect of this research. In addition, this project's objective is to discover how the waveguide size (dimension) impacts single-mode waveguides in the infrared region. The investigation includes single-mode polarization with both transverse-magnetic TM0 and transverse-electric TE0 polarization. The waveguide is reliant on the effective index of different mediums, and sizes of substances, they have a significant role in generating waveguide with minimum loss (minimum dispersion). The study's most crucial finding is that single-mode can be achieved in silicon with widths ranging from 0.4-4.5 μm and height ranging from 0.4-0.7 μm as well as analysis the characteristics of mode polarization and explain those parameters have a massive role in the waveguide like effective index, sizes of structure and wavelength. In keeping with our modal analysis, we also state the mode's characterization and direct some factors' influence on the waveguide.

Revolutionary developments have been started in the field of superconductors since their discovery. High-temperature superconductors have been a focus of attention in advanced technology for many scientists because of their potential applications. Therefore, many changes are made in the products that use such materials. It remains one of the most exciting research fields and can revolutionize the physics and technology of the future. It is required to understand and learn the history and basic principles of Superconductivity for its better implications. Considering its recent discoveries, its current applications can be studied. The mechanism of ‘HTS’ is much easier to understand after the significant development made in the field of Superconductivity. The purpose of this work is to better understand and appreciate research in the field of Superconductors. Basically, HTS has been used in many areas, but much progress is needed. HTS can be used in optoelectronics technologies and countless other applications after the effects seen by such improvements. In particular, this review focuses on the high-temperature BSCCO compound and its manufacture by the Solid-State reaction method and the PLD technique, which could be useful to electronics technology, particularly optoelectronic devices applications. Superconducting electronics devices have a lot of promise for future high-efficiency optoelectronics.

Iraqi petroleum refineries produce large quantities of base lubricating oils (lube oils). Managing the influence of nano-additives on the lube oil nanofluids is required deep understanding to explain the resulting new specifications of produced nano-lubricants. The present study investigated the effect of Al2O3 NPs addition on the thermal properties of lube oil stock-60. Different mass additions of 0.25, 0.65, 1.05, 1.45, and 1.85 wt.% of Al2O3 NPs at operating temperatures of 20-50°C were evaluated. Also, the thermal conductivity coefficient of the prepared nanofluid was studied at the full range of the experimental temperatures (20-50°C). It was noted that the addition of Al2O3 NPs improved the thermal properties of the prepared nano-lubricant due to the high thermal conductivity of the added Al2O3 NPs. Moreover, the greatest improvement in the thermal conductivity of modified nano-lubricating oil was 13.02% at added Al2O3 mass fraction of 1.85%. The results indicated that the viscosity index of the prepared nano-lubricant was improved dramatically with Al2O3 NPs addition increase at measured standard temperatures of 40 and 100°C. The viscosity index of lubricant nanofluid is increased up to 2.46% at a weight fraction of 1.85%. The flashpoint increased by 1.33, 3.54, 5.75, 7.52, and 9.73% for mass fraction of 0.25, 0.65, 1.05, 1.45, and 1.85 wt.%, respectively. Furthermore, the highest flashpoint value was 248oC of prepared nanofluid lube oil with 1.85 wt.% of Al2O3 NPs. Finally, the produced nano-lubricating oil has high operating quality with economic feasibility. Furthermore, an accurate correlation for predicting the viscosity of both types of nano-lubricants was provided.

Due to its flexibility, small size and low cost, the nanomaterials films are widely desired in optical applications. In this study, a solid nanodiamond (ND) film was fabricated and characterized for photonics applications. The nanocomposite films were prepared by drop casting method where ND was embedded into poly Vinylidene fluoride-trifluoroethylene (PVDF-TrFE) as a host polymer. Both physical and optical properties of the prepared film were investigated. To analyze the structure of fabricated ND-PVDF-TrFE film, various measurement methods were adopted, including a field emission scanning electron microscopy (FESEM), Fourier transform spectroscopy (FTIR), and x-ray diffraction. The nonlinear absorption property of ND-PVDF-TrFE film was studied by balanced twin detector technique (BTDT) using mode-locked fiber laser with pulse width of 1.4 ps at wavelength of 1566 nm. The results showed that the saturable-absorption features of ND-PVDF-TrFE film possess a good nonlinear performance. Furthermore, a good nonlinearity with a high modulation depth makes the ND-PVDF-TrFE film a good candidate to use in many photonics systems such as saturable absorber (SA) in passive Q-switched or mode-locked fiber lasers.

In this research, composite material consist of PMMA and MMA as a matrix materials was prepared and reinforced by natural fibers (sisal fibers) in different concentrations (5, 10%wt). The conventional processing technique for complete dentures was followed to prepare the composite specimens. FTIR test was carried out to reinforcement material (sisal fibers) before and after salinization to determine, whether or not there is chemical bond between reinforcements materials and saline coupling agent. Physical tests such as thermal conductivity, water sorption and solubility were performed on all specimens. The results refer to a highly significant differences in: thermal conductivity, water sorption and solubility of reinforced specimens compared with pure specimens. Increasing the fiber concentration showed a slight decrease in the thermal conductivity of PMMA specimens reinforced with sisal fibers, and increase both water sorption and solubility of composite specimens. FTIR results showed a new absorption band was developed after sialne treatment.

In this work, the physical properties of iron sulfide (FeS2) thin films deposited by the chemical spray-pyrolysis (CSP) technique were studied. The thin films are deposited on glass substrates at 200oC, using FeCl3 salt with thiourea (NH2)2CS as precursors. Structural analysis of X-Ray diffraction manifested that the thin films contain two phases: Marcasite and Pyrite in planes (110), (111) at angles 2θ =26.3°, 2θ =28.3° respectively. Optical properties analysis showed that the prepared iron sulfide thin-films were highly absorbing in the UV-Visible range and the absorption coefficient was in the range of 1.6x105 cm-1 with a relatively low resistivity of about 0.49 (Ω.cm). The calculated activation energy (Ea) was 0.024 eV and the bandgap value was 2.45 eV. Moreover, the FeS2 thin films were also deposited on (CdO) to fabricate a heterojunction photocell. In conclusion, there is the feasibility of preparing low-cost and highly absorbing iron sulfide (FeS2) thin films for optoelectronic applications with acceptable homogeneity using the spray-pyrolysis technique.

In the present work, Laser Induced Breakdown Spectroscopy (LIBS) has been utilized to investigate two forms of aluminum samples, namely Al in the form of the nanoparticles (NPs) and a bulk (pellet). The Al target was irradiated by pulsed Nd-YAG laser with wavelength 1064 nm to produce plasma. The plasm spectrum is analyzed in the wavelength range between 250 nm and 700 nm. Some plasma parameters were calculated, including electron temperature (????????), plasma density (ne) and Debye length (????????) for different laser energies. The temperature of electrons was computed employing the Boltzmann plot technique, and the electrons density was computed utilizing the Stark broadening technique. This work aims to investigate the effect of laser energy on the plasma parameters and the influence of using two different forms of targets on these parameters. It was noted that increasing the laser energy from (400 mJ) to (700 mJ) resulted in an increase in electrons temperature from (0.52 eV) to (0.65 eV) and an increase in electron density from (57.38×1016 cm-3) to (67×1016 cm-3) for the nano aluminum plasma, whereas the electrons temperature increased from (0.52 eV) to (0.59 eV) and the electron density increased from (43.88×1016 cm-3) to (55.05×1016 cm-3) for the bulk aluminum plasma. From the obtained results, it's concluded that using identical laser energies, the electron temperature and electron density of the plasma generated from aluminum in the form of nanoparticles are greater than that generated from aluminum in the bulk form. The differences in the calculated parameters for Al NPs and Al bulk belong to their different structures and morphologies as presented via Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) methods.

Oxidative stress has been linked to the development of a variety of malignancies, including leukemia. Furthermore, the incidence of leukemia increases with age due to an increase in the number of free radicals reacting with age and a lower ability of the immune system to detoxify those free radicals. This study aims to investigate the levels of antioxidant activity and their relationship with various types of leukemia. The current study was carried out in the Hematology section of Baghdad Teaching Hospital/Medical City from November 2020 to January 2021. Patients with leukemia (n = 60) were divided into four groups based on their leukemia type: Acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), chronic lymphoid leukemia (CLL), and chronic myeloid leukemia (CML). These groups were compared to 30 healthy subjects. In this study, serum levels of superoxide dismutase (SOD) and vitamin E were measured using an enzyme-linked immunosorbent assay. The findings revealed that (Mean±SE) SOD levels were observed to be raised with age, but (Mean±SE) vitamin E levels decreased with age in leukemia patients. There were no statistically significant differences in gender (males and females). Compared with healthy subjects, the results showed a significant increase in SOD levels in ALL, AML, CLL, and CML (P < 0.01). There were no statistically significant differences observed in vitamin E levels in ALL, AML, and CML except for the CLL group, which showed a significant decrease compared to the healthy subjects. Positive correlations were found between SOD and age (r = 0.367 P < 0.01). These results suggest that SOD and vitamin E levels play a critical role as an indicator of acute and chronic leukemia.

Silver nanoparticles were prepared by the chemical reduction method. Silver nitrate was taken as a metal precursor and sodium borohydride as a reducing agent with polyvinyl alcohol (PVA) stabilizers of different concentrations, polyvinylpyrrolidone (PVP). X-ray diffraction (XRD), transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques have been used, these measurement results showed that the prepared material is silver nanoparticles. The average size of silver nanoparticles using the Scherrer equation with values ranging from 8.49-12.15nm. TEM images showed that the silver nanoparticles are spherical in size between 5-47nm. Nanoscale distribution of silver nanoparticles (AgNPs) prepared at different concentrations was studied by AFM. Silver nanoparticles showed high antimicrobial and antibacterial activity against Gram-positive bacteria such as Escherichia Coli and Gram-negative Staphylococcus aureus, whose bacterial activity was dependent on the concentration of PVA and PVP and the degree of intramolecular accumulation. Low concentrations of PVP lead to increase the activity, while high concentrations of PVA give better activity.

To develop bio-packaging materials, nanocomposite films of cellulose acetate reinforced with titanium dioxide and zinc oxide nanoparticles were prepared, by the casting method at different weight ratios of ZnO nanoparticles (1.5, 2, and 2.5) wt% and a constant weight ratio of 2 wt% TiO2. ZnO and TiO2 nanoparticles were tested using scanning electron microscopy (SEM). The mechanical properties (tensile strength and elongation) were improved at a fixed level of Cellulose Acetate+ 2% TiO2+1.5wt% ZnO loading. Beyond that level of loading, they decreased. The tensile strength was decreased due to some degrees of agglomeration of filler particles above a critical content. Fourier-Transform Infrared Spectroscopy (FTIR) was conducted to reveal the microstructures and chemical composition of as-prepared composite films. The wettability of the films was also determined by the sessile drop method. An increase in contact angle was also observed by the addition of ZnO content from 70.6° to 77.1° compared to pure Cellulose Acetate, which indicated a value of 61.3°. Antibacterial activity against Escherichia coli and Staphylococcus aureus was enhanced after incorporation of ZnO-TiO2 compared with pure CA. The enhanced wettability and antibacterial activity of the prepared films suggest that they could be used for packaging applications.

Chitosan holds net ionic positive charges, which contribute its ability to chemically bind with negatively charged fats, lipids, metal ions, proteins, and microorganisms. Magnesium oxide (MgO) nanoparticles are important inorganic materials with a wide band-gap used in many applications such as catalysts, antibacterial and medical products. The aim of this study was to investigate the effect of Chitosan (CHT) hydrogel loaded MgO nanoparticles on the bacterial growth. CHT/ poly vinyl alcohol (PVA)/ poly ethylene glycol (PEG) hydrogel was blended with various amounts of MgO nanoparticles. The surface morphology of the obtained blends was investigated by Field Emission Scanning Electron Microscope (FE-SEM). Evidently, surfaces with appropriate roughness were obtained for most of the prepared hydrogels. Fourier Transform Infrared Spectroscopy (FT-IR) and Energy Dispersive X-Ray analysis (EDX) were also included in this paper. Thermal properties of all samples was studied by DSC-TGA curves. The antibacterial activity of the prepared hybrids CHT/PVA/PEG/MgO nanoparticles have performed against gram positive bacteria Staphylococcus aureus (S.aureus) and Streptococcus, as well as gram negative bacteria Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E.coli). In this study, MgO nanoparticles various proportions presented high efficiency towards gram positive microorganisms. High resistance of gram negative bacteria against the final products was extremely detected according to measured inhibition zones which were between (0-9) mm.

Osteoporosis is a systematic bone disorder characterized by bone mass loss and bone tissue architectural degeneration. The incidence of osteoporosis in women increases with age, reflecting the considerable increase in bone loss rate in postmenopausal women once estrogen loses its protective influence. The purpose of this study was to determine the levels of Osteocalcin, Vitamin D, and other parameters that influence bone quality and increased bone fragility in postmenopausal Iraqi women with type 2 diabetes mellitus (T2DM). The levels of vitamin D receptor and vitamin D binding protein in serum are studied for the first time in our study. The present study included 89 postmenopausal women aged 50-70 years old, 62 T2DM patients, and 27 controls. Ten of the T2DM patients were considered osteoporotic, 28 were considered osteopenia, and 22 were normal; this classification is according to the WHO criterion. After matching for body mass index (BMI) and age for patients and controls, results show a significant difference in serum Osteocalcin, vitamin D, and vitamin D binding protein levels in patients compared to controls. In our study, diabetic patients appear with high levels of Osteocalcin, vit.D, and vitamin D binding protein compared with non-diabetic control. The processes underlying diabetes mellitus-induced skeletal problems are unknown. Anti-diabetic medications might have an adverse or favorable effect on bone metabolism. The study concludes that managing skeletal health in postmenopausal women entails screening fracture risk factors, lowering modifiable risk variables through dietary and lifestyle modifications, and using a pharmacologic treatment for individuals at high risk of osteoporosis or fracture. Women with osteoporosis must be managed for the rest of their lives.

In this study, Au:TiO2 nanoparticles (NPs) are prepared by using the laser ablation method in liquid at different laser energies (600, 800, and1000 mJ). After that, Au: TiO2 NPs were deposited on porous-Si(PS). Porous silicon (PS) is synthesized by using the photo-electrochemical etching (PECE) of n-type crystalline Si (c-Si) wafers of (100) orientation. The intensity of the etching current density was (4, 12, and 20 mA/cm2), with 16% (HF), and the etching time was 15 minutes. The X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM), UV–visible spectrophotometry, and electrical properties are used to characterize the obtained particles. From the photo-detector measurements, the spectral responsivity curves three inclusive regions; the first peak was due to the absorption of UV light by Au: TiO2 NPs. The second peak was corresponding to the visible light absorption with the PS layer and the third peak was due to the absorption edge of the Si substrate. The higher responsivity of Au: TiO2 NPs/PS photo-detector was found to be 2.56A/W for specimens prepared at laser energy 800mJ.

The present work is a study of some properties of PbI2 deposited on porous silicon (n-PSi) by using the thermal evaporation technique. X-ray diffraction, scanning electron microscopy, UV–Vis spectrophotometer, and FTIR analysis were used to characterize the structural, optical, and morphological properties of n-Psi. X-ray diffraction showed that the PbI2 film has a hexagonal polycrystalline structure, while FE-SEM images showed porous silicone in Photoelectrochemical etching, the pore distribution is irregular and the pore refers to the increased surface area of the silicon. SEM images of pbI2 film showed that particles were scattered and resembled gravel in size. The estimated optical energy value of thin films of PbI2 was 2.6 eV. PbI2 film has lower transmittance values at short wavelengths, but as the wavelength increases, the transmittance values gradually increased. The greatest transmittance value was 0.88. From FTIR analysis, chemical bonds were determined between porous silicon and PbI2.