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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
Tue Aug 01 2023
Journal Name
Civil Engineering Journal
Structural Strengthening of Insufficiently Designed Reinforced Concrete T-Beams using CFRP Composites
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This study aims to compare the response of reinforced concrete (RC) T-beams strengthened with carbon fibre-reinforced polymer (CFRP) composite with that of non-strengthened control beams when subjected to monotonic two-point loading until failure for flexural once and shear again. The experimental programme tested eight RC T-beams, which included two reference beams without strengthening and six strengthened beams. The eight beams were divided into two main groups according to strengthening (flexural and shear). Experimental analysis was performed to study the effect of the CFRP laminate width in the flexural group and the spacing of CFRP U-wrap sheets in the shear group on the ultimate load capacity, load-strain relationship, and l

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Publication Date
Tue Aug 01 2023
Journal Name
International Journal Of Electrical And Computer Engineering (ijece)
Energy generation by crystalline silicon photovoltaic network per meter square in Iraq
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<span lang="EN-US">Iraqi people have been without energy for nearly two decades, even though their geographic position provides a high intensity of radiation appropriate for the construction of solar plants capable of producing significant quantities of electricity. Also, the annual sunny hours in Iraq are between 3,600 to 4,300 hours which makes it perfect to use the photovoltaics arrays to generate electricity with very high efficiency compared to many countries, especially in Europe. This paper shows the amount of electric energy generated by the meter square of crystalline silicon in the photovoltaic (PV) array that already installed in 18 states in Iraq for each month of the year. The results of the meter-square of PV arr

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Publication Date
Sun Nov 04 2018
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
MEASURING OBESITYLEVEL BY BIO-ELECTRICAL IMPEDANCE ANALYSIS TECHNIQUE AND COMPARED TO TRADITIONAL METHODS: MEASURING OBESITYLEVEL BY BIO-ELECTRICAL IMPEDANCE ANALYSIS TECHNIQUE AND COMPARED TO TRADITIONAL METHODS
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This study aimed to determine obesity level of some population in Baghdad by using Bio-electrical impedance analysis (BIA) and compared with anthropometric measurements such as body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR). Statistical analysis results of linear correlation coefficients for obesity indicators showed that BIA correlation 0.92 was most significant and reliable for obesity measurement.

Results of BIA method for age group 20-29 years showed that 44.4% of females were healthy body while 37.8% of males suffer from increased body fat. Results of age group 30-39 year showed that 32.6 of females were in healthy body and 42% of males were obese. In case age group 40-4

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Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Synthesis and characterization of carbon nanospheres by catalytic CVD method
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Carbon nanospheres (CNSs) were successfully prepared and synthesized by Catalytic Chemical Vapor Deposition (CCVD) by using camphor as carbon source only, over iron Cobalt (Fe-Co) saturated zeolite at temperature between (700 oC and 900 °C), with different concentrations of camphor, and reaction time. The synthesized CNSs were characterized using Scanning Electron Microscopy (SEM), X-ray diffraction spectroscopy (XRD), and Fourier Transform Infrared (FTIR). The carbon spheres in different sizes between 100 nm and 1000 nm were investigated. This work has done by two parts, first preparation of the metallic catalyst and second part formation CNSs by heat treatment.

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Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Preparation and characterization of Activated Carbon from Iraqi Corns Stalks
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In this paper, Activated Carbon was successfully prepared from local Iraqi material namely corns stalks .Zinc chloride ZnCl2 was used as activating agent with different concentrations (20%, 40%, 60%) for 72 hours. followed by carbonization at 450 C for (2) hour. UV-Spectrophotometer used for measuring absorbance of methylene blue solutions before and after adsorption. the maximum amount adsorbed for methylene blue material of the prepared activated Carbon was studied by Langmuir adsorption isotherm. Other characteristics of the resulting activated Carbon also discussed, such as pH, Moisture Content and ash content. Finally Activated carbon prepared in this work has good properties compared to the standard samples in such a way it could be

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Publication Date
Sun Dec 07 2014
Journal Name
Baghdad Science Journal
Corrosion Behavior of Copper and Carbon Steel in Acidic Media
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The corrosion behavior of copper and carbon steel in 1M concentration of hydrochloric acid (HCl) and sulphuric acid (H2SO4) has been studied. The corrosion inhibition of copper and carbon steel in 1M concentration of hydrochloric acid (HCl) and sulphuric acid (H2SO4) by Ciprofloxacin has been investigated. Specimens were exposed in the acidic media for 7 hours and corrosion rates evaluated by using the weight loss method. The effect of temperature (from 283 ºK to 333 ºK), pH (from 1to 6), inhibitor concentration (10-4 to 10-2) has been studied. It was observed that sulphuric acid environment was most corrosive to the metals because of its oxidizing nature, followed by hydrochloric acid. The rate of metal dissolution increased with incre

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Publication Date
Mon Mar 23 2020
Journal Name
Baghdad Science Journal
Role of Carbon Dioxide on the Corrosion of Carbon Steel Reinforcing Bar in Simulating Concrete Electrolyte
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The main factors that make it possible to get the corrosion of reinforcing steel in concrete are chloride ions and the absorption of carbon dioxide from the environment, and each of them works with a mechanism which destroys the stable immunity of rebar in the concrete. In this work the effect of carbon dioxide content in the artificial concrete solution on the corrosion behavior of carbon steel reinforcing bar (CSRB) was studied, potentiostatically using CO2 stream gas at 6 level of concentrations;  0.03 to 2.0  weight percent, and the effect of rising electrolyte temperature was also followed  in the range 20 to 50ᴼ C. Tafel plots and cyclic polarization procedures were obeyed to investigate the c

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Publication Date
Wed Dec 30 2009
Journal Name
Iraqi Journal Of Physics
Electrical Investigation of PSi/Si (n-type) structure
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In this work, porous Silicon structures are formed with photochemical etching process of n-type Silicon(111) wafers of resistivity (0.02.cm) in hydrofluoric acid (HF) of concentration (39%wt) under light source of tungeston halogen lamp of (100 Watt) power. Samples were anodized in a solution of 39%HF and ethanol at 1:1 for 15 minutes. The samples were realized on n-type Si substrates Porous Silicon layers of 100m thickness and 30% of porousity. Frequency dependence of conductivity for Al/PSi/Si/Al sandwich form was studied. A frequency range of 102-106Hz was used allowing an accurate determination of the impedance components. Their electronic transport parameters were determined using complex impedance measurements. These measu

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Publication Date
Sun Nov 20 2022
Journal Name
Journal Of Optics
Good cleavers for fiber-optic communication technology
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Fiber optics technology has shown immense applications in the areas of medicine, telecommunication, and imaging. For these particular applications, it requires fibers with precise cleaving. In this paper, we will demonstrate a quick, simple and efficient cleaving method that can result in a high-quality fiber surface that works well for many fiber-optic applications. The smooth tip and good surface quality obtained on the cleaved surface of optical fiber is demonstrated by using a microscope imaging system and was flat surface with a 900 angle for perpendicular cleavages. The precision cleaver provides smooth and high-quality cleaves on single-fiber surfaces as opposed to the ruby scribe pen. The defects that may occur during the cleaving p

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Publication Date
Sun Dec 03 2017
Journal Name
Sci. Int.(lahore)
IMPROVING NO2 SENSITIVITY OF POROUS SILICON BY FUNCTIONALIZATION ITS SURFACE WITH COPPER AS CATALYST
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In this work, porous silicon gas sensor hs been fabricated on n-type crystalline silicon (c-Si) wafers of (100) orientation denoted by n-PS using electrochemical etching (ECE) process at etching time 10 min and etching current density 40 mA/cm2. Deposition of the catalyst (Cu) is done by immersing porous silicon (PS) layer in solution consists of 3ml from (Cu) chloride with 4ml (HF) and 12ml (ethanol) and 1 ml (H2O2). The structural, morphological and gas sensing behavior of porous silicon has been studied. The formation of nanostructured silicon is confirmed by using X-ray diffraction (XRD) measurement as well as it shows the formation of an oxide silicon layer due to chemical reaction. Atomic force microscope for PS illustrates that the p

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