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Enhanced thermal and electrical properties of epoxy/carbon fiber–silicon carbide composites
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The silicon carbide/carbon fiber (SiC/CF) hybrid fillers were introduced to improve the electrical and thermal conductivities of the epoxy resin composites. Results of Fourier transform infrared spectroscopy revealed that the peaks at 3532 and 2850 cm−1 relate to carboxylic acid O–H stretching and aldehyde C–H stretching appearing deeper with an increased volume fraction of SiC. Scanning electron microscopic image shows a better interface bonding between the fiber and the matrix when the volume fraction of SiC particles are increased. As frequency increases from 102 Hz to 106 Hz, dielectric constants decrease slightly. Dissipation factor (tan δ) values keep low and almost constant from 102 Hz to 104 Hz, has a slight increase after 104 Hz, and obtain relaxation peaks approximately between 105 and 106 Hz. A sharp increase in dielectric constant and dissipation factors is observed in epoxy (Ep)/CF composites with 30 vol.% of SiC. The increase in electrical conductivity of composites may result from the increased chain ordering by annealing effect. The electrical conductivities of the Ep/CF composites are decreasing with the increasing volume fraction of SiC. It is attributed to the introduction of insulating SiC. The glass transition temperature ( T g) of the Ep/CF-30 vol.% SiC composite was 352 C, which was higher than other composites. The decomposition temperature at 5% weight loss, decomposition temperature at 10% weight loss, and maximum decomposition temperature of the Ep/CF-30 vol.% SiC composite were about 389.5°C, 410.7°C, and 591°C, respectively, and were higher than pure epoxy and other composites. A higher thermal conductivity of 1.86 W (m K)−1 could be achieved with 30 vol.% SiC/CF hybrid fillers, which is about nine times higher than that of native epoxy resin of 0.202 W (m.K)−1.

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Publication Date
Wed Mar 23 2011
Journal Name
Ibn Al- Haitham J. For Pure & Appl. Sci.
Image Compression Using Proposed Enhanced Run Length Encoding Algorithm
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In this paper, we will present proposed enhance process of image compression by using RLE algorithm. This proposed yield to decrease the size of compressing image, but the original method used primarily for compressing a binary images [1].Which will yield increasing the size of an original image mostly when used for color images. The test of an enhanced algorithm is performed on sample consists of ten BMP 24-bit true color images, building an application by using visual basic 6.0 to show the size after and before compression process and computing the compression ratio for RLE and for the enhanced RLE algorithm.

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Publication Date
Thu Oct 19 2023
Journal Name
Journal Of Optics
Production and characterization of porous silicon via laser-assisted etching as photodetector: effect of different HF concentrations
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Publication Date
Mon May 01 2023
Journal Name
Cuadernos De Economía
The Role of Carbon Pricing Mechanisms and Renewable Energy Technologies in Reducing Carbon Emissions: Evidence from the International Economy
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Abstract: The international community now places significant emphasis on achieving zero carbon emissions, requiring both new researchers and experienced policymakers to prioritise this goal. This article examines the effects of carbon taxes, carbon cap and trade, renewable energy (RE) production and consumption, and economic growth (EG) on carbon emission reduction in the United States, Japan, Canada, and Australia. The study collected secondary data from the World Development Indicators (WDI) secondary source spanning the years 1991 to 2022. The study examines the relationship between variables using the cross-sectionally augmented autoregressive distributed lag (CS-ARDL) approach. The findings indicate that carbon taxes, carbon cap and tr

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Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Structure dependence of gamma ray irradiation effects on polyurethane and epoxy resin studied by PAL technique
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Positron annihilation lifetime (PAL) technique has been employed to
study the microstructural changes of polyurethane (PU), EUXIT 101
and epoxy risen (EP), EUXIT 60 by Gamma-ray irradiation with the
dose range (95.76 - 957.6) kGy. The size of the free volume hole and
their fraction in PU and EP were determined from ortho-positronium
lifetime component and its intensity in the measured lifetime spectra.
The results show that the irradiation causes significant changes in the
free volume hole size (Vh) and the fractional free volume (Fh), and
thereby the microstructure of PU and EP. The results indicate that
the γ-dose increases the crystallinity in the amorphous regions of PU
and increas

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Publication Date
Fri Sep 30 2011
Journal Name
Journal Of Electrochemical Science And Technology
Electrodeposition of Silicon from Fluorosilicic Acid Produced in Iraqi Phosphate Fertilizer Plant
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Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Engineering
Determination of Mono-crystalline Silicon Photovoltaic Module Parameters Using Three Different Methods
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For modeling a photovoltaic module, it is necessary to calculate the basic parameters which control the current-voltage characteristic curves, that is not provided by the manufacturer. Generally, for mono crystalline silicon module, the shunt resistance is generally high, and it is neglected in this model. In this study, three methods are presented for four parameters model. Explicit simplified method based on an analytical solution, slope method based on manufacturer data, and iterative method based on a numerical resolution. The results obtained for these methods were compared with experimental measured data. The iterative method was more accurate than the other two methods but more complexity. The average deviation of

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Publication Date
Tue Nov 21 2023
Journal Name
Mater Sci: Mater Electron
Pulsed laser deposition of nanostructured CeO2 antireflection coating for silicon solar cell
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Increasing the power conversion efficiency (PCE) of silicon solar cells by improving their junction properties or minimizing light reflection losses remains a major challenge. Extensive studies were carried out in order to develop an effective antireflection coating for monocrystalline solar cells. Here we report on the preparation of a nanostructured cerium oxide thin film by pulsed laser deposition (PLD) as an antireflection coating for silicon solar cell. The structural, optical, and electrical properties of a cerium oxide nanostructure film are investigated as a function of the number of laser pulses. The X-ray diffraction results reveal that the deposited cerium oxide films are crystalline in nature and have a cubic fluorite. The field

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Publication Date
Sun Sep 07 2014
Journal Name
Baghdad Science Journal
Analytical Study of near Mobility Edge Density of States of Hydrogenated Amorphous Silicon
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Experimental results for the density of states of hydrogenated amorphous silicon due to Jackson et al near the valence and conduction band edges were analyzed using Levenberg-Marquardt nonlinear fitting method. It is found that the density of states of the valence band and the conduction band can be fitted to a simple power law, with a power index 0.60 near the valence band edge, and 0.55 near the conduction band edge. These results indicate a modest but noticeable deviation from the square root law (power index=0.5) which is found in crystalline semiconductors. Analysis of Jackson et al density of states integral J(E) data over about (1.4 eV) of photon energy range, showed a significant fit to a simple power law with a power index of 2.11

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Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
The study of thermal description for non-thermal plasma needle system
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Cold plasma is a relatively low temperature gas, so this feature enables us to use cold plasma to treat thermally sensitive materials including polymers and biologic tissues. In this research, the non-thermal plasma system is designed with diameter (3 mm, 10 mm) Argon at atmospheric pressure as well as to be suitable for use in medical and biotechnological applications.
The thermal description of this system was studied and we observed the effect of the diameter of the plasma needle on the plasma, when the plasma needle slot is increased the plasma temperature decrease, as well as the effect of the voltages applied to the temperature of the plasma, where the temperature increasing with increasing the applied voltage . Results showed t

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Publication Date
Mon Mar 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Synthetic Sacks as Reinforced Fibers in the Thermosetting Composites
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This study was carried out to investigate the preparation of thermosetting polymeric blend consisting of three adhesive types, namely: epoxy, polyvinyl formal (PVF) and unsaturated polyester. Both of epoxy and PVF were used as a matrix-binder at fixed weight. Whilst unsaturated polyester was used at different weights and added to the matrix so as to produce prepared epoxy-PVF-unsaturated polyester blend. Several experiments were performed at different operating conditions, mixing speed and time at room temperature to identify the most favorable operating conditions. The optimum mixing speed and mixing time for the prepared blend were 500rpm and 5 minutes respectively.

      Solid wastes-synthetic sack fib

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