Publications
Effect of Innovative Glassy House and Secondary Reflectors Combination with Nanocoating on Fast and Slow Increase of Receiver Temperature in Parabolic Solar Collector
Feb 20, 2025Journal Eximia journal
Publisher AIP Conference Proceedings
DOI https://doi.org/10.47577/eximia.v14i1.534
Issue 1
Volume 14
The purpose of this work is to enhance the ability of the receiver for increasing in temperature absorbing, firstly achieving a rapid rise the temperature in a relatively short time through geometric variables, and secondly, achieving higher temperatures and maintaining them over time for long periods using nano-coatings.The present study related to the development of parabolic dish solar concentrator as a design by using the concept of a glass house with an attempt to invent and manufacture small-sized secondary reflectors to be placed inside the greenhouse which is placed on the side of the receiver at an angle of 45° to reflect the rays that may pass directly without passing through the receiver. The three primary modifications include, copper receiver, a glassy spherical cover, and secondary reflectors. A copper tube is made up of coil in spiral shape and it is fixed in the focus of dish to obtain maximum solar energy. The higher absorber temperature was 58°C with out any modification.The absorber temperature increased with first modification to( 87°C,50%), by using second modification (a glassy spherical ) it was found that the glass cover improved the rapid and greater temperature rise which increased to (132°C, 137%), Also by using of a glassy spherical cover with secondary reflectors (third modification), the increasing absorber temperature are raised to (162°C ,179%). The temperature of the receiver will be less lost with an increase in wind speed in the second and third modifications.Thirdly, a nanocoating was used for each of (CuO, TiO2) to determine the extent to which it is possible to achieve an increase in the absorbed temperature for a relatively long time without any modification once which increased to (71°C,22.4% for CuO nanocoating) and decreased to (50C, -60% for TiO2 nanocoating). Using the third modification with nanocoating and for a relatively long period time, this research found that the temperature increased (175°C,201 % for CuO nanocoating), and ( 115 C, 98% for TiO2 nanocoating).This means that the nanocoating of (TiO2) without an air-tight cover leads to a decrease in the absorption efficiency compared to the absorbing surface alone, but it increases with the use of the third modification, while the coating with (CuO) increases the absorbed temperature in both cases and is more efficient than titanium oxide, the higher temperature difference of the nanocoating is due to higher thermal conductivity of CuO nanoparticles.These results can enhance the improvement of designs used for the same purpose in the future.
Study a structural and magnetic properties of a hematite (αFe2O3) nanoparticles synthesized by hydrothermal method
Nov 19, 2024Journal AIP Conference Proceedings
Publisher AIP Conference Proceedings
DOI https://doi.org/10.1063/5.0236250
Issue 1
Volume 3219
The nanoparticles of α Fe2O3 have been produced using a hydrothermal method. X-ray diffraction of Iron Oxide (αFe2O3) shows a nanocrystal structure α Fe2O3 phase and we found that the crystallite size is increasing as reaction time increased. FTIR indicates that the products consist of αFe2O3 nanoparticles. From SEM results we found irregular morphology of cubic nanoparticles with a side lengths that vary between of (70-93) nm, and uniform morphology of spherical nanoparticles that have a limit size distribution, and the diameter range in (⁓50-75)nm, and thus a good dispersed with size-controlled cubic, the nanostructures of (α-Fe2O3) with a spherical shapes were obtained by changing the time of reaction process, as well as the morphology of sample 6 (periodic time 15h and cooled down to (RT) then heating with 5h), there are growing and increasing of grain size of product as a comparison with sample 2which prepared at constant time, this mean that this adding are an affect new parameter that can be used in hydrothermal method. Magnetic measurements at (RT room temperature) displayed the maximum coercivity (Hc=~342 Oe) is observed for sample6 as a comparison with same constant time of sample2, indicating that the magnetization of a hematite is have ahigh sensitivity to structural properties such as shape, size and defects in crystal structure and the samples shows weak ferromagnetic Property with symmetric hysteresis loops.
EFFECTS OF ANNEALING TEMPERATURE ON STRUCTURAL AND GAS SENSING PROPERTIES OF PBS THIN FILMS OBTAINED BY CHEMICAL BATH DEPOSITION
Jun 1, 2024Journal International Journal of Applied Sciences and Technology
Publisher MINAR
DOI http://dx.doi.org/10.47832/2717-8234.19.5
Issue 2
Volume 6
In this research, studying the structural properties and gas sensing of PbS thin films grown on cleaned glass substrates by using chemical bath deposition (CBD) method. The thin films are annealed in air at 100 ℃, 200 ℃, 300 ℃, and 350 ℃ temperatures for 2hrs. The structural and morphological properties were investigated by X-ray diffraction (XRD), atomic force microscopy(AFM), field emission scanning electron microscopy (SEM), and energy –dispersive X-ray analysis(EDX). XRD patterns which showed that the preferred orientation growth along (200) diffraction peaks for as-deposited film while, a significant increase in the peak intensity of (111) plane when annealed at 100℃. The crystallization of PbS thin films obtained for asdeposited and annealed at 100 ℃, 200 ℃, 300 ℃ and 350 ℃ temperature are nanocrystalline cubic structure. The minimum value of grain size was 44.963 nm when the thin film annealed at of 350 ℃. We notice from the FE-SEM images that the number of voids decreases on the film surface with increment of annealing temperature and the floral shapes also disappeared for the annealed film at an annealing temperature of 300℃. The energy dispersive X-ray analysis indicated that the thin films contains Pb and S elements. The sensor response of the as-deposited and post heat treated films of PbS sensors toward H2S gas was investigated in the temperature range of RT-200 ℃ with gas concentration of 100 ppm. The sensitivity of H2S gas on the PbS thin films are dependent on grains shape and excessive chemisorbed oxygen molecules on surface of thin film.
Synthesis and Characterization of copper oxide(II) nanoparticles prepared by hydrothermal process
Sep 22, 2019Journal Journal of University of Babylon for Pure and Applied Sciences
Publisher Journal of University of Babylon for Pure and Applied Sciences
DOI https://doi.org/10.47577/eximia.v14i1.534
Issue 4
Volume 27
Hydrothermal process was used to prepare CuO nanoparticles. CuO nanoparticles can be prepare without organic solvents, expensive raw materials by a hydrothermal method. XRD diffraction reveals that CuO nanoparticles have a monoclinic structure with particle size 20nm , and AFM analysis showed that the diameter of the Grain size is in a nanometer range. The analysis by FTIR spectra assure that the composition was CuO, and the features of vibrational types of Cu–O were fixed. also the optical properties was analysed with UV–vis showed that CuO nano particles have considerable a blue shift , which have aband gab equal to (4.9 eV ) , and this is because the effect of quntum confienment of prepared CuO nano particles.
Preparation and Characterization of Zno Nano particles Prepared by Hydrothermal Method
May 9, 2019Journal Tikrit Journal of Pure Science
Publisher Tikrit Journal of Pure Science
DOI https://doi.org/10.25130/tjps.v24i3.374
Issue 3
Volume 24
In this study,the nanoparticles of zinc oxide were readily prepared through Hydrothermal process by using zinc nitrate hexahydrate, and Sodium hydroxide as aprecursors. The surface topology, and crystalline structure of prepared ZnO nanoparticles were studied. X-ray diffraction (XRD) revealed that the prepared ZnO nano particles is highly crystalline, having (wurtzite) crystal structure. The optical analysis by UV–vis showed that these ZnO nano particles have considerable blue shift in the optical band gap energy (Eg = 4.9eV), and this may be to the quantum confinement effect of nano particles. The FT-IR results shows the existence of OH, COO, H2O groups the characteristic vibrational modes of Zn–O were identified. and AFM analysis showed that the diameters of the ZnO particles is in ananometer range of (70-74)nm