بحوث سكوبس — محمد هاشم عباس

In the present work, fabrication of CS - SnO2 - ZnO and CS - ZrO2 - Fe2O3 nanocomposites was investigated to apply in different flexible nanoelectronics fields. The morphological and dielectric features of CS - SnO2 - ZnO and CS - ZrO2 - Fe2O3 nanocomposites films were studied at frequency ranged from 100Hz to 2MHz. The results recognized that the dielectric constant and dielectric loss of CS - SnO2 - ZnO and CS - ZrO2 - Fe2O3 nanocomposites films were decreased but the conductivity was increased with increasing frequency. The dielectric constant, dielectric loss and conductivity of CS were enhanced when the SnO2 - ZnO and ZrO2 - Fe2O3 nanoparticles content increased. The final outcomes showed the CS - SnO2 - ZnO and CS - ZrO2 - Fe2O3 nanocomposites films may be useful in numerous electrical and electronics applications. © 2026, Russian Academy of Natural Science. All rights reserved.

The present work aims to design and manufacture PS-SiO2-MnO2 promising nanostructure films to apply in several optical and nano-optoelectronics fields. The electronic, morphological, microstructure, and optical features of PS-SiO2-MnO2 nanostructures were investigated. Results confirmed that the SiO2-MnO2 NPs showed good distribution inside the PS matrix. The PS absorbance was improved by 44.7% at λ = 340 nm when the content of SiO2-MnO2 NPs increased to reach 2.8 wt.%, this performance making (PS-SiO2-MnO2) nanostructures multifunctional nanomaterials for nanoelectronics and photonics approaches. The absorbance has the highest values at UV-spectra, this result making (PS-SiO2-MnO2) nanostructures suitable for UV-blocking and radiation shielding compared with other types of nanostructures. The indirect allowed band gap was reduced from 3.65 eV to 3.4 eV with the rise of SiO2-MnO2 NPs content to reach 2.8 wt.%. The PS optical factors were enhanced with the increase in SiO2-MnO2 NPs content. The electronic features indicated that the (PS-SiO2-MnO2) nanostructures included excellent electronic parameters. The final results indicated that the (PS-SiO2-MnO2) nanostructures are promising films for futuristic optics and nanoelectronics applications. The (PS-SiO2-MnO2) nanostructures illustrated remarkable optical and electronic characteristics compared with other works, including excellent optical behaviour, good electronic features, and low cost. © 2025 Chemical Society of Ethiopia and The Authors.

The current work aims to fabricate of futuristic nanocomposites films based on poly-methyl methacrylate (PMMA) filled with silicon carbide (SiC) and zinc oxide(ZnO) nanostructures to apply in many advanced optical fields. The optical, morphological, microstructure, and electronic features of (PMMA-SiC-ZnO) nanocomposites films are examined. The results demonstrated that the PMMA absorption increases of 81.1% at λ = 360 nm when the SiC-ZnO NPs content increased to 2.8 wt.%. The transmittance decreased of 23.7% at λ = 360 nm, these results making the (PMMA-SiC-ZnO) films as promising nanomaterials for optical and nanoelectronics fields. The energy gap reduced from 3.5 eV to 3.03 eV with growing SiC-ZnO NPs content to 2.8 wt.%. The other optical parameters were improved with rising of SiC-ZnO NPs content. The results of electronic properties showed to enhance the electronic factors of PMMA by adding the SiC-ZnO NPs. The obtained results confirmed that the nanocomposites films of (PMMA-SiC-ZnO) are promising nanosystem for development of nanoelectronics and optical fields. © The Author(s), under exclusive licence to Springer Nature B.V. 2025.

The present work aims to fabricate of chitosan doped with SnO2-ZnO nanoparticles to employ in various optical and electronics applications. The study included the compact of (SnO2/ZnO) nanocomposites on optical features of chitosan to be used in variety of optics and electronics applications. The chitosan-SnO2/ZnO nanocomposites have been prepared by utilizing casting technique with various concentrations of (SnO2/ZnO) nanoparticles and chitosan. The optical features have been investigated at a range of wavelengths from (320 - 920 nm). The analysis reveal that when (SnO2/ZnO) nanoparticles ratio has been increased, absorption value of chitosan-(SnO2/ZnO) nanocomposites was boosted whereas the transmittance value was drop down. Whenever (SnO2/ZnO) nanocomposites ratio have been rise, the band gap was reduced from 3.33 to 2.9 eV for allowed transition and from 3.13 to 2.51 eV for forbidden transition. The other optical features of chitosan-SnO2/ZnO nanocomposites have been boosted. Finally, the outcomes of optical features reveal that the chitosan-SnO2/ZnO nanocomposites are being possible to be utilized in a variety of applications. © 2025, Walailak University. All rights reserved.

The goal of this research is to create PMMA and SiO2-Si3N4 nanoparticles doped PMMA films with enhanced structural and electrical properties to employ in various quantum electronics fields. The casting process was used to create the (PMMA-SiO2-Si3N4) nano-composite films. In the development of nanocomposite materials, the hybrid nanocomposite films with 2.3%, 4.6% and 6.9% contents of nanoparticles were prepared. Using an optical microscope (OM), the morphology of the nanocomposites was examined. At room temperature, the electrical characteristics of (PMMA-SiO2-Si3N4) nano-composites were investigated. The results revealed that the dielectric constant and dielectric loss of (PMMA-SiO2-Si3N4) nanocomposites reduced as the frequency of the applied electric field increased. The electrical conductivity of alternating current rises with rising frequency. With increasing concentrations of SiO2-Si3N4 nanoparticles, the dielectric constant, dielectric loss, and AC electrical conductivity of (PMMA-SiO2-Si3N4) nanocomposites were enhanced. When the SiO2-Si3N4 NPs content reached 6.9% at 100Hz, the dielectric constant increased from 3.86 to 4.76 while the dielectric loss increased from 0.19 to 0.29. Finally, the obtained results demonstrated that the (PMMA-SiO2-Si3N4) nanocompo sites have elevated values of dielectric constant compared with dielectric loss, which makes them suitable for a variety of quantum electronics applications. © 2025, Lviv Polytechnic National University. All rights reserved.

The goal of the present study is to fabricate PVA/PEG/ZnO-GO nanocomposites and investigate their optical features. The PVA/PEG/ZnO-GO nanocomposites have been prepared by utilizing casting technique with various concentrations of (ZnO-GO) nanoparticles. The optical features have been investigated at a range of wavelengths from (220-820 nm). The analysis reveal that when (ZnO-GO) nanoparticles ratio has been increased, absorption value of PVA/PEG was boosted whereas the transmittance value was drop down. Whenever (ZnO-GO) nanocomposites ratio have been rise, the band gap was reduced from 4.7 to 3.9 eV for allowed transition from 4.3 to 3.2 eV for forbidden transition. The reduce of energy gap making PVA/PEG/ZnO-GO nanocomposites are suitable for many optoelectronics applications like sensors, diodes, solar cell, transistors and photovoltaic cell. The other optical features of PVA/PEG/ZnO-GO nanocomposites have been boosted. Finally, the outcomes of optical features reveal that the PVA/PEG/ZnO-GO nanocomposites are being possible to be utilized in many optoelectronics applications. © 2025, Walailak University. All rights reserved.

The development of new materials with improved features requires the use of nanocomposite materials and polymer blends. Their special combination provides enhanced performance in a range of environmental, biomedical, and industrial applications. Using the traditional casting procedure, the polyvinyl alcohol (PVA)/poly acrylic acid (PAA) polymer blend doped with silicon carbide (SiC)/multi-walled carbon nanotubes (MWCNTs) nanocomposites was successfully created. Nanocomposites (NPs) were evenly distributed over the polymer mix matrix, and the polymer blend was well dispersed in the solution, according to the optical microscopy image. The films’ surface morphology of the polymer blend exhibits a homogeneous grain distribution, according to FE-SEM examination. The generated materials do not include any new functional groups, according to the FTIR analysis, indicating that just a physical interaction has taken place. It was observed from the study of optical properties that the increase in SiC/MWCNTs nanoparticles led to enhancement of all optical features, such as absorbance, refractive index, optical conductivity, real and imaginary parts of the dielectric constant, while transmittance and energy gaps were decreased. The energy gap decreased from 4.8 eV to 3.82 eV for the allowed transition, and from 4 eV to 3.02 eV for the forbidden transition. These results reveal that PVA/PAA doped SiC/MWCNTs films can be utilized in a variety of advanced applications. © 2025 by the authors.

FeCo binary alloys with high saturation magnetization have been envisioned as the most promising compounds in the fabrication of solid-state devices, including hard drives. Forming multilayered nanowires (MNWs) of these alloys would allow for ultra-high density data storage by reversing spins in the 3D space. However, thorough experimental investigations into the angular magnetic properties of FeCo/Cu MNWs have not been performed yet. Here, we first electrochemically deposit FeCo/Cu MNWs into nanopores of anodic alumina membranes using a pulse method, and then comprehensively investigate their angular magnetic properties using a vibrating sample magnetometer equipped with first-order reversal curve (FORC) software. We also change the Cu layer length (LCu) in the range of 3‒20 nm while keeping the FeCo layer length constant to 180 nm, and measure hysteresis loops and FORC diagrams for 0° ≤ θ ≤ 90°. We observe that the coercivity continuously increases with increasing θ from 0° to 45° when LCu ≤ 12 nm, and that it remains nearly constant for LCu = 20. For all LCu values, the angular dependence of hysteresis loop coercivity shows sharp reductions with increasing θ over 45°, especially for θ ≥ 70°. These events are accompanied with the appearance of perceptible single vortex states in the angular FORC diagrams and significant enhancements in magnetostatic interactions between the FeCo layers. Our evaluations based on the angular dependence of FORC coercivity peaks indicate that the magnetization reversal of the FeCo/Cu MNWs is dominated by a vortex mode, monotonically increasing the coercive field to above 3000 Oe at θ = 82.5° for the lowest LCu. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

This work objects to prepare of tin oxide (SnO2)-silicon carbide (SiC) doped- polyvinyl alcohol (PVA) as future nanomaterials to utilize in the nanoelectronics and optics devices. The structural, optical and dielectric characteristics of PVA/SnO2/SiC films were investigated. The results indicated to the absorption (A) rise about 90.7% at UV-region (λ = 300 nm) and transmittance decreases about 41.3%, this behavior can be useful in optical, anti-reflectance and electronic nano-devices. The energy gap of PVA reduced from 5 to 2 eV with rise in the SnO2/SiC ratio to (6 wt%) which make the PVA/SnO2/SiC films appropriate in several nano-electronics and nano-optics fields. The other optical parameters for PVA enhanced with an increase in the SnO2/SiC ratio. Results of the dielectric properties showed the dielectric constant (ε') and electrical conductivity (σAC) improved about 62.3% and 76.2% when content of SnO2/SiC reached (6 wt%) at (f = 100 Hz) which is welcomed in potential and energy storage applications. Finally, the attained results showed the PVA/SnO2/SiC films can be considered as a promising nano-materials to employ in various nano-electronics and optics applications with exceptional optical and electrical properties compared of other nanosystems. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

The present work aims to synthesize of polystyrene (PS)-cerium oxide (CeO2)- silicon carbide (SiC) nanostructures as promising materials to utilize in various optics nanoelectronics devices like transistors, photovoltaic cell, electronic gates and other applications. The structural, optical and electrical characteristics of PS/CeO2/SiC nanostructures have been investigated. The results indicated that the absorbance (A) was increased about 46.1% at UV-spectra (λ = 300 nm) and 59.1% at visible- spectra (λ = 500 nm). The energy gap of PS was decreased from 4 eV to 2.8 eV when the ratio of CeO2/SiC nanostructures reached (4.8 wt.%) which made it suitable for several optics and nanoelectronics fields. The optical parameters of PS matrix were enhanced with an increase in the CeO2/SiC NPs content. Results of the AC electrical properties showed that the dielectric constant (ε') and AC electrical conductivity (σAC) were improved about 35% and 66.1% with rise in the CeO2/SiC nanostructures content at (f = 1 kHz). Finally, the obtained results showed the PS/CeO2/SiC nanostructures are promising for various optics and nanoelectronics fields. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

This work aims to improve the structural, optical and electrical characteristics of silicon carbide(SiC) yttrium oxide(Y2O3) nanostructures doped poly-methyl methacrylate(PMMA) to utilize it for various optics and potential nanodevices like light filters, transistors sensors diodes, lasers, electronics gates which were distinguished by low cost, excellent optical and electrical properties, flexible and low weight. Results showed that the absorbance of PMMA enhanced about 76.3% at photon wavelength(λ = 440 nm) when the SiC/Y2O3 NPs content reached (4.8wt.%). The energy gap value of PMMA reduced from 4.3 eV to 3 eV with an increase in the SiC/Y2O3 NPs content. Doping PMMA with SiC/Y2O3 NPs improved the optical constants. The dielectric constant and AC electrical conductivity) of PMMA enhanced about 22.5% and 31.6 when the SiC/Y2O3 NPs content reached (4.8w.%) at frequency (f = 100 Hz). The obtained results indicated that the doping PMMA with SiC/Y2O3NPs improved the optical, structural and electrical characteristics which made the PMMA/SiC/Y2O3 nanostructures are promising materials for optics and potential nanodevices in the development of optoelectronics approaches. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.

Due to the poor thermal conductivity of phase change materials (PCMs), the operation of Latent heat thermal energy storage (LHTES) is restricted by the limited heat exchange rate between PCMs and heat sources or sinks. The current review discusses the effects of magnetic field, rotation, tilt angle, and vibration on the discharging and charging heat performance of PCMs and nano-enhanced PCMs (NEPCMs) which are encapsulated in various container geometries and orientations based on melting and solidification standpoints. From this review, it is concluded that the orientation and design of the heat exchanger has a significant effect on the melting/solidification performance. The melting and solidification performance have been improved by increasing the magnetic number and decreasing the Hartmann number. Moreover, rotating cavity in a counter direction of buoyancy flow has improved the melting rate/time. The optimum tilting angle varies depending on the thickness of PCM layers. In terms of the vibration effect, frequency and amplitude/frequency are found to have an important role at low and high discharge rates, respectively. Following a comprehensive review, a few suggestions are provided as future research topic in this field. © 2023

The current article objects to fabricate of PVP-Si3N4-Al2O3 nanostructures films as future nanomaterials and promising to utilize in the nanoelectronics and optics fields. The morphological and optical characteristics of PVP-Si3N4-Al2O3 nanostructures films were investigated. The optical characteristics results indicated to the absorption(A) rises with 57.8% at UV-region(λ = 340 nm) while transmission decreases with 21.7% when the concentration rises from 12.5 gm/L to 50 gm/L, this performance can be functional in optical, solar collectors, anti-reflectance and semiconductors fields. The energy gap of PVP reduced from 3.05 eV to 2 eV when the concentration reached 50 gm/L which make the PVP-Si3N4-Al2O3 films appropriate in numerous nanoelectronics fields. The other optical parameters: refractive index, absorption coefficient, real and imaginary parts of dielectric constants, extinction coefficient and optical conductivity of PVP enhanced with an increase in the concentration. The results of thermal energy storage application showed to get on melting time gain reached 55.8% which makes the PVP-Si3N4-Al2O3-H2O nanofluids are appropriate in the thermal energy storage applications. Finally, the attained results demonstrated the PVP-Si3N4-Al2O3 nanostructures are important promising nano-materials to employ in solar collectors and various optics approaches with outstanding optical characteristics compared of other nanosystems. © 2023, The Author(s), under exclusive licence to Springer Nature B.V.

Although phase change materials are significant for heat storage, the fundamental issue with energy storage is their poor heat conductivity. Three scenarios have been widely provided to enhance the discharging efficiency of a triplex-tube heat storage unit: the first uses fins, the second uses nanoparticles, and the third use both fins and nanoparticles. This paper's primary goal is to introduce a thorough evaluation of the state-of-the-art research on solidification enhancement of phase change materials in a triplex-tube thermal energy storage system, as well as a summary of employing fins, nanoparticles, and both fins and nanoparticles. This study examines several more factors that influence the solidification enhancement of phase change materials (PCMs). These variables include the effect of employing various fin geometries, the temperature of the thermal fluid, heat exchanger length and pipes' diameters, the velocity of the coolant, the length and thickness of fins, fins' intensity, and the geometries of PCM units. Discussions centre on findings and recommendations from earlier research. According to the outcome of this work, the solidification enhancement of PCM suggests plans for further research initiatives. © 2023

The amino acid histidine is an important bioactive molecule for growth and tissue repair and has an influential role as a neurotransmitter in the human musculoskeletal and central nervous systems. Therefore, excessive deficiency of this amino acid and the proteins induced by it causes many diseases. For this reason, the specific and sensitive detection of the amino acid histidine is very important. Surface-enhanced Raman scattering (SERS) is a sensitive method for detecting low concentrations of various substances, especially biomaterials. The silver nanoparticles (AgNPs)-coated substrates were employed in the present investigation to detect the amino acid histidine to control the diseases caused by it. First, a chemical method named Tollens was applied to fabricate AgNPs, and then, the Fluorine-doped tin oxide (FTO) substrates were coated with AgNPs by applying voltage and through the electrodeposition technique. Therefore, AgNPs were fabricated using the Tollens method, as well as the size distribution of nanoparticles was specified as being equal to 130–150 nm by employing dynamic light scattering. Moreover, UV–Vis spectroscopy was employed for the characterization of prepared substrates and AgNPs. The results show that the plasmonic peak tends toward longer wavelengths following the self-array of AgNPs. In addition, it was proved by the field-emission scanning electron microscope (FE-SEM) images that AgNPs on the surface of FTO substrates were distributed non-uniformly. The limit of detection (LOD) was equal to 10−9 for SERS-active substrates for the purpose of detecting this amino acid. Moreover, for ten repeated calculations, the mean relative standard deviation (RSD) was achieved to be 3.86%. Furthermore, the values for the enhancement factor were obtained to be 1.344 × 105 and 1.389 × 105 via experimental and simulation methods, respectively. Thus, the results obtained from Raman indicate that by applying the developed methods, SERS-active substrates coated with AgNPs for the detection of amino acid histidine show advantageous results for SERS-based investigations and can cause the development of nanosensors. © 2022 Elsevier B.V.

The technique of phase change thermal storage is an effective solution to overcoming the problem of a mismatch between the supply of energy and the demand for it. In this work, a numerical investigation of the influence of an air bubble placement on the paraffin wax melting (PCM) inside of a rectangular cavity is described. The PCM refers to the melting of paraffin wax. In order to conduct a numerical investigation of the research, the enthalpy-porosity combination (the ANSYS / FLUENT 16 program) is used. For the purpose of this experiment, phase change materials for paraffin wax are being used (RT58). As a result of examining several locations of the air bubble (top, center, and bottom) in the rectangular cavity, this paper investigates the influence of air bubbles on the dissolution process and heat transfer. Additionally, the paper investigates the influence of air bubbles on the amount of time that it takes for paraffin wax to melt. When compared to the presence of air bubbles in the center, the presence of air bubbles at the bottom and top of the solution has resulted in a 7% reduction in the amount of time needed to complete the process of dissolution. It has been shown that the presence of air bubbles naturally advances the dissolving process, and it has also been demonstrated that the dissolution process will be accelerated when it is known that the volume of PCMs is greater since it includes the volume of air bubbles © 2023,Mathematical Modelling of Engineering Problems. All Rights Reserved.

Polymeric nanocomposites have drawn a lot of interest when it comes to innovative materials because of their enhanced optical, electrical, and magnetic properties. These materials have a high rising modulus, are flame resistant, and may also halt oxidation and agglomeration. These improvements in properties are related to interactions between nanoparticles and polymers. The addition of nanoparticles to polymers prolongs their life, changes their surface via passivation defect levels, and provides low cost, simple device manufacture, as well as adjustable electrical and optical properties. This study examines the properties and potential uses of nanofluids made from inorganic nanostructures doped with PEG. The results demonstrate that when the concentration of ZrO2/SiC NPs increased to 12wt%, the electrical conductivity of nanofluids increased by roughly 43.6%. Additionally, when the concentration of ZrO2/SiC nanoparticles increases, the melting time reduces. Additionally, when the concentration of ZrO2/SiC NPs increases from 3 weight percent to 12 weight percent within 15 minutes, the growth of melting time reaches 51.2%, and the absorbance increases by approximately 80.3% while transmittance decreases by about 82.5%. © A. Hashim, F.L. Rashid, M.H. Abbas, B.H. Rabee, 2023.

Heat is transferred to the storage medium during the charging phase of thermal energy storage (TES), and then released during the discharging phase. It may be used for industrial operations like metallurgical transformations or solar power facilities. Heat is stored in materials that alter temperature, phase, or chemical composition in sensible, latent, and thermochemical media, respectively. Optimal heat storage has a long history. This study investigates the optical and electrical properties of MgO/SiC-H2O nanofluids for applications including thermal energy storage. Results indicate that when MgO/SiC NP concentrations were raised to 1.2 gm/L, absorbance rose by approximately 66.9% and transmittance by about 54%. Additionally, the increase in MgO/SiC NP concentration will raise absorbance, which indicates improved nanofluid dispersion. Additionally, when MgO/SiC nanoparticle concentrations approach 1.2 gm/L, the electrical conductivity of nanofluids increases by roughly 49.2%, and the melting time reduces as the concentration of MgO/SiC nanoparticles rises. © F.L. Rashid, A. Hashim, M.H. Abbas, A. Hadi, 2023.

FeCo/Cu multilayer NW arrays are fabricated using a pulsed electrodeposition method in 50 nm pore diameter anodic aluminum oxide templates. The magnetic layer (LFeCo) and nonmagnetic layer (LCu) thicknesses range between 23–225 and 2–50 nm, respectively. These layer designations make it possible to find a thin Cu layer, in which the magnetic behavior of multilayer NWs is similar to that of alloy NWs. A threshold LCu is also obtained, representing dual behavior of the coercive field in FeCo/Cu multilayer NWs. These behaviors, in turn, are associated with an increase in magnetizing and demagnetizing interactions, as evidenced by hysteresis curve and first-order reversal curve experiments. By extracting magnetic parameters such as the average coercive field, irreversible coercive field, magnetostatic interaction distribution, and reversibility, the magnetic behavior of FeCo/Cu multilayer NWs is comprehensively explored as a function of LFeCo. © 2022 Elsevier B.V.

This study examines the dielectric properties of polyvinyl alcohol (PVA)/polyethylene glycol (PEG) doped with chromium oxide (Cr2O3) nanoparticles, with the aim of leveraging these properties in electronic and electric nanodevices. The effect of Cr2O3 nanoparticle concentration on the dielectric constant, dielectric loss, and AC electrical conductivity of the composites was systematically investigated. The results demonstrate that both the dielectric constant and dielectric loss decrease with increasing frequency, but increase with the concentration of Cr2O3 nanoparticles. Conversely, AC electrical conductivity was found to increase with both frequency and Cr2O3 nanoparticle concentration. The enhanced dielectric properties of the PVA/PEG/Cr2O3 nanocomposites make them suitable for various applications in the field of electronics and energy storage. The study provides new insights into the design of materials for electrical and electronics applications. © 2023 Lavoisier. All rights reserved.

Films of PVA and PVA doped with Fe2 O3/Co2 O3 nanoparticles are fabricat-ed to employ in different electronics fields. The dielectric properties of (PVA–Fe2 O3/Co2 O3) nanocomposites are investigated in frequency range from 100 Hz to 5 MHz. The results show that both the dielectric constant and the dielectric loss of (PVA–Fe2 O3 /Co2 O3) nanocomposites are reduced, while the A.C. electrical conductivity increases with increasing of the frequency of applied electric field. The dielectric constant, the dielectric loss and the A.C. electrical conductivity of PVA increases with increasing of the Fe2 O3/Co2 O3-nanoparticles’ content. The dielectric-properties’ results show that the (PVA–Fe2 O3/Co2 O3) nanocomposites can be suitable for different electronics fields. © 2023, G.V. Kurdyumov Institute for Metal Physics of N.A.S. of Ukraine. All rights reserved.

In present work, fabrication of poly(vinyl alcohol) (PVA)/CeO2/SiC nano-composites with lightweight and low cost is investigated. The dielectric properties of PVA/CeO2/SiC nanocomposites are studied. The results show that both the dielectric constant and the dielectric loss of PVA/CeO2/SiC nanocomposites are decreased with an increasing in the frequency, while the electrical conductivity is increased as frequency increases. Dielectric constant, dielectric loss and electrical conductivity of PVA are increased with an increasing in the CeO2/SiC-nanoparticles’ concentration. The results on dielectric properties show that the PVA/CeO2/SiC nanocomposites can be useful in various electronics applications. © 2023, G.V. Kurdyumov Institute for Metal Physics of N.A.S. of Ukraine. All rights reserved.

This work aims to prepare of Ag-Ti nanostructures and investigating their optical characteristics to employ in medical and industrial fields. The optical characteristics were measured by recording the absorbance spectrum. The obtained results demonstrated to improve in absorbance (A) values of Ag NPs with adding of Ti NPs content. The transmittance (T) and energies gaps (Eg) values of Ag NPs were reduced with rising of Ti NPs content which lead to made the Ag-Ti nanostructures may be employed in different approaches of medical and industrial fields. © 2023 Author(s).

In this paper, the influence of manganese oxide (MnO2 NPs) on optical parameters of PEG/PVP films was investigated to use in various fields. The optical characteristics were tested at wavelength(?) ranged from 300 nm to 900 nm. The results of optical characteristics of PEG/PVP/MnO2 films demonstrated the absorption rises but transmission reduces with the rise in MnO2 NPs content. The optical parameters of PEG/PVP were developed as MnO2 NPs content increase. © 2023 Author(s).

In this research, the PVP/PEG/In2O3 nanostructure films were prepared and testing the optical characteristics to make it useful in many optical and electronics fields. The results illustrated to rise in the absorbance while reduce in the transmittance and energies gaps values of PVP/PEG with rising of In2O3 NPs content. Also, the optical parameters of PVP/PEG enhanced by adding of In2O3 NPs content. © 2023 Author(s).

FeNi/Cu multilayer nanowire arrays were first electrochemically deposited in nanopores of alumina membranes by a single-bath pulse method, and then their magnetic behavior was investigated by using a vibrating sample magnetometer (VSM) instrument equipped with first-order reversal curve (FORC) software. The Cu deposition pulse time varied from 2.4 to 9.6 s at a constant FeNi pulse time of 2.88 s, and hysteresis curves and FORC diagrams of the resultant nanowires were extracted at magnetic field angles in the range of 0° <0< 90°. At each 9< 90°, the results of VSM hysteresis curves showed that coercivity and remanence ratio decreased with increasing the pulse time. Furthermore, magnetostatic interaction field distributions were enhanced at each 0 when decreasing the pulse time. This enhancement was ascribed to the lower separation of the ferromagnetic FeNi layers along the nanowire length, influencing the magnetostatic interactions. The vanation of FORC coercivity as a function of 0 revealed the dominance of the vortex domain wall mode in the magnetic behavior, regardless of the Cu pulse time.Abstract. © 2023 American Institute of Physics Inc.. All rights reserved.

The dielectric properties of polyvinyl alcohol/polyethylene glycol/TiN (PVA/PEG/TiN) nanocomposites are studied to use them in different electronic nanodevices. The PVA/PEG/TiN nanocomposites’ films are synthesized by using the casting method. The dielectric properties of PVA/PEG/TiN nano-composites are tested at frequency (f) ranged from 100 Hz to 5 MHz. The results demonstrate that the dielectric properties of fabricated nanocomposites (ε', ε" and σA.C.) are improved with increase in the TiN-nanoparticles’ concen-tration. Components (ε' and ε") of complex dielectric constant are decreased, while the A.C. electrical conductivity (σA.C.) is increased with increase in the frequency. The results indicate that the PVA/PEG/TiN nanocomposites can be useful in different electronic nanodevices. © 2023, G.V. Kurdyumov Institute for Metal Physics of N.A.S. of Ukraine. All rights reserved.

Films of PVA/PEG/CeO2 nanocomposites are fabricated to be used in different electronic applications. The A.C. electrical properties of PVA/PEG/CeO2 nanocomposites are studied. The dielectric properties are examined at frequencies from 100 Hz to 5 MHz. The experimental results indicate that the A.C. electrical properties of PVA/PEG/CeO2 nanocompo-sites are enhanced with increase in the CeO2 nanoparticles’ content. The dielectric parameters are changed with rise in the frequency. © 2023, G.V. Kurdyumov Institute for Metal Physics of N.A.S. of Ukraine. All rights reserved.

Nanocomposites of PVA/PEG blend doped with ZrC nanoparticles (NPs) are fabricated by using casting process with various contents of PVA/PEG blend and ZrC NPs. The A.C. electrical properties of PVA/PEG/ZrC nano-composites are investigated at frequencies from 100 Hz to 5 MHz. The experimental results show that the A.C. electrical properties (dielectric constant, dielectric loss and A.C. electrical conductivity) of PVA/PEG blend are increased with increase in the ZrC NPs’ ratio. In addition, dielectric parameters of PVA/PEG/ZrC nanocomposites are changed with rise in the frequency from 100 Hz to 5 MHz. © 2023, G.V. Kurdyumov Institute for Metal Physics of N.A.S. of Ukraine. All rights reserved.

PCMs have a huge storage capacity, improved heat transfer capability, and a constant operating temperature. PCMs have a weak conduction heat transfer coefficient, which slows melting and reduces energy storage. To increase thermal energy storage system efficiency, performance augmentation technologies are being developed. These strategies include using fins, metal foams in PCMs, and high-thermal-conductivity nanoparticles. This article presents a complete overview of experimental, numerical, and experimental and numerical investigations on melting enhancement of phase change material in triplex-tube thermal energy storage. Fins, nanoparticles, and both are used. This article reviews works on melting enhancement of phase transition material in triplex-tube thermal energy storage. In addition, recent findings and research developments will be summarized. This article covers setting up, examining settings, and discovering results. © 2022 Lavoisier. All rights reserved.

In this study, many samples have been synthesized by using solution casting technique with different additive content of Chromium oxide nanoparticle (Cr2O3NPs), poly vinylalcohol (PVA) and polyethylene glycol (PEG). The UV-Vis. spectrophotometer used to record the absorbance spectrum in the range of (200-800) nm. The absorption of UV waves is improved while the transmittance is reduced when Cr2O3 NPs were added to the polymeric system which are useful for a number of applications including low-cost UV protection and solar radiation shield. When Cr2O3 NPs concentrations increased, the optical energy gap for indirect transition (allowed and forbidden) was decreased. Furthermore, all the optical constant has been improved. © 2022 Lavoisier. All rights reserved.

Incompressible fluid flow research uses lid-driven cavity as a benchmark issue to measure computer simulation accuracy. Flow within a hollow includes recirculation, turbulence, eddies, instability, impingement, flow separation, attachment with walls (moving and stationary), fluid entrapment in the recirculation area, and other fluid flow phenomena. In this article, forced convection in a lid-driven square cavity with a sliding top wall and hemispherical obstruction is mathematically illustrated. This chamber filled with Newtonian fluid was exposed to a moving wall (5, 10, 15, and 20 m/s), as selected in the literature. The finite volume technique using the SIMPLER algorithm is used to solve the complete governing equations with the Boussinesq approximation, whereas the analytical approach uses the parallel flow assumption. The moving wall disrupts the cavity's flow field, according to the results. Also, moving wall produces great mixing between the flow field below it and the hollow. The static pressure fluctuates from 0.6 m to 1 m (contact with the moving wall). Also, dynamic pressure increases linearly until 0.7 m, then decreases linearly until 1 (contact with the moving wall). In addition, the inner surface's velocity varies randomly along the location while the others remain constant. © 2022,Mathematical Modelling of Engineering Problems.All Rights Reserved.

From fast magnetic memories with low-power consumption to recording media with high densities, realizing the magnetization reversal and interaction of magnetic layers would allow for manipulating the ultimate properties. Here, we use a pulsed electrochemical deposition technique in porous alumina templates (50 nm in pore diameter) to fabricate arrays of nanowires, consisting of FeNi layers (26-227 nm in thickness) with disk to rod-shaped morphologies separated by ultra-thin (3 nm) Cu layers. By acquiring hysteresis curves and first-order reversal curves (FORCs) of the multilayer nanowire arrays, we comprehensively investigate magnetization reversal properties and magnetostatic interactions of the layers at different field angles (0° ≤ θ ≤ 90°). These involve the extraction of several parameters, including hysteresis curve coercivity (H c Hyst ), FORC coercivity (H c FORC ), interaction field distribution width (ΔH u ), and irreversible fraction of magnetization (IF m ) as a function of θ. We find relatively constant and continuously decreasing trends of H c Hyst when 0° ≤ θ ≤ 45°, and 45° < θ ≤ 90°, respectively. Meanwhile, angular dependence of H c FORC and IF m shows continuously increasing and decreasing trends, irrespective of the FeNi layer morphology. Our FORC results indicate the magnetization reversal properties of the FeNi/Cu nanowires are accompanied with vortex domain wall and single vortex modes, especially at high field angles. The rod-shaped layers also induce maximum ΔH u during the reversal process, owing to enhancements in both magnetizing and demagnetizing-type magnetostatic interactions. © 2022 IOP Publishing Ltd.