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bsj-7204
The Influence of Ablation Speed on the Synthesis of Carbon Nanostructures Via Pulsed Laser Ablation of Asphalt in Ethanol
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Pulsed liquid laser ablation is considered a green method for the synthesis of nanostructures because there are no byproducts formed after the ablation. In this paper, a fiber laser of wavelength 1.064 µm, peak power of 1 mJ, pulse duration of 120 ns, and repetition rate of 20 kHz, was used to produce carbon nanostructures including carbon nanospheres and carbon nanorods from the ablation of asphalt in ethanol at ablation speeds of (100, 75, 50, 10 mm/s).  The morphology, composition and optical properties of the synthesized samples were studied experimentally using FESEM, HRTEM, EDS, and UV-vis spectrophotometer. Results showed that the band gap energy decreased with decreasing the ablation speed (increasing the ablation time), the minimum mean particle size of the synthesized samples was 76 nm at an ablation speed of 100mm/s, while the maximum mean particle size was 98 nm at ablation speed of 50 mm/s, the nanospheres were agglomerated to form larger spherical nanoshapes. All the synthesized carbon nano colloids exhibited a blue-green PL emission. It was concluded that the presence of carbon nanorods has an effect on the optical properties of the synthesized nanospheres.

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Publication Date
Tue Mar 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
The effect of gender diversity of board directors and accounting conservatism on firm value
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The study aims to investigate the relationship between the gender diversity of board director, the accounting conservatism and firm value in Iraqi firms. The sample was represented by 30 Iraqi firms listed on the Iraqi market over the period 2017. The research was based on the main hypothesis that gender diversity has a positive relationship with conservatism and firm value, that conservatism as an intermediate variable will enhance the positive relationship between gender diversity and firm value. The study reached results that support the research hypotheses. The appointment of females to the board helps improve the provision of conservative accounting information and avoids overstate when reporting earnings. Based on these res

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Publication Date
Sun Dec 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
The Production of Ethanol from Sugar Beet Waste by Immobilized Saccharomyces Cerevisiae
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Saccharomyces Cerevisiae cells were immobilized in calcium alginate beads and activated charcoal for use in the
production of ethanol from batch fermentation of sugar beet waste. Treatment of the waste with NaOH to increase the
ability of lignocellulose material to hydrolysis by acid (2N H2SO4) to monosaccharide and disaccharide (mainly glucos).
The high reducing sugar concentration obtained was equal to 9.2gm/100ml (10Brix) after treatment. Fermentation
parameters, are (pH, glucose concentration (2.5-25 gm/100ml), immobilized agent concentration (2.5-25 gm/100ml)
were studied to find the optimum physiological condition. And the highest ethanol concentration obtained from the
fermentation in the presence of 20%(wt/v) ca

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Publication Date
Wed Oct 18 2023
Journal Name
Cogent Engineering
Investigating the effect of nanomaterials on the Marshall properties and durability of warm mix asphalt
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This research aims to investigate the effect of four types of nanomaterial on the Marshall properties and durability of warm mix asphalt (WMA). These types are; nano silica(NS), nano carbonate calcium (NCC), nano clay(NC), and nanoplatelets (NP). For each type of Nanomaterial, three contents are tried as following; NS(1%, 3%, and 5%), NCC(2%, 4%, and 6%), NC(3%, 5%, and 7%), and NP (2%, 4%, and 6%) by weight of asphalt cement. Following Marhsall mix design method, the optimum asphalt cement content is determined, thereafter the optimum dosage for each nanomaterial is obtained based on the highest Marshall stability value. The durability of the control mix (no nanomaterial) and modified mixtures have been compared based on moisture damage, r

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Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Engineering
Effect of Heat Treatments and Carbon Content on the Damping Properties of Structural Steel
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Low- and medium-carbon structural steel components face random vibration and dynamic loads (like earthquakes) in many applications. Thus a modification to improve their mechanical properties, essentially damping properties, is required. The present study focuses on improving and developing these properties, significantly dampening properties, without losing the other mechanical properties. The specimens used in the present study are structural steel ribbed bar ISO 6935 subjected to heating temperatures of (850, 950, and 1050) ˚C, and cooling schemes of annealing, normalizing, sand, and quenching was selected. The damping properties of the specimens were measured experimentally with the area under the curve for the loadi

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Publication Date
Mon Jan 01 2024
Journal Name
2nd International Conference For Engineering Sciences And Information Technology (esit 2022): Esit2022 Conference Proceedings
ZnO nanostructures as low concentration NO2 gas sensor and impact the temperature on sensing properties
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Zinc oxide (ZnO) nanostructures were synthesized through the hydrothermal method at various conditions growth times (6,7 and 8 hrs.) and a growth temperature (70, 90, and 100 ºC). The prepared ZnO nanostructure samples were described using scanning electron microscopy (SEM) and X-ray diffractometer to distinguish their surface morphologies and crystal structures. The ZnO samples were confirmed to have the same crystal type, with different densities and dimensions (diameter and length). The obtained ZnO nanostructures were used to manufacture gas sensors for NO2 gas detection. Sensing characteristics for the fabricated sensor to NO2 gas were examined at different operating temperatures (180, 200, 220, and 240) ºC with a low gas concentrati

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Publication Date
Thu Jun 08 2023
Journal Name
Iraqi Journal Of Laser
PDF Effectiveness of 980nm diode Laser in reduction the diameters of exposed dentinal tubules for hypersensitive tooth
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Abstracts:

Background: The oral cavity is a complex environment, both structurally and functionally, the hard and soft tissues are in close a proximity. Oral tissues subjected to wear throughout the life, that threatened the vitality of the pulp or increase the sensitivity of dentinal tubules. One of the common dental problems is loss of enamel or cementum, which stimulate the nerve ending in or near the pulp and manifested as pain sensation. Aim of the study: This study had done to evaluate the effects of 980nm diode Laser in diameters reduction of exposed dentinal tubules analyze the results and morphological changes of irradiated dentine surface by FE-SEM (field emission scann

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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of strategic Supremacy on strategic success A case study in Thi Qar Governorate
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Purpose To test the effect of strategic Supremacy on strategic success A case study in Thi Qar Governorate, methodology/approach – this is a mandatory entry.

a case study was used and applied to the Department managers of Government of the province of Thi Qar, Research limitations/implications – It is clear that the strategic Supremacy variable is not being used effectively to achieve strategic success.

Practical implications – use strategic supremacy positively to Support for strategic success. implementing and monitoring ignorance of them in how to use thi

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Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Investigation of Nonlinear Optical Characteristics of the Multi-Wall Carbon Nanotubes (MWCNT's) Suspensions using Nonlinear Self-Diffraction of a Laser Beam
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Nonlinear diffraction patterns can be obtained by focusing a laser beam through a thin slice of the material. Here, we investigated experimentally the formation of the far field nonlinear diffraction patterns of cw laser beam at 532 nm passing through a quartz cuvette containing multi-wall carbon nanotubes (MWCNT's) suspended in acetone and in DI water at concentrations of 0.030.wt.%, 0.045 wt.%, 0.060 wt.%, and 0.075 wt.%. Our results show that increasing the concentration of both types of suspensions (MWCNTs in acetone and MWCNTs DI water) led to increase in the number of pattern rings which indicates an increase in their nonlinear refractive indices. Moreover, MWCNTs DI water suspension at a concentration of 0.075 wt. % was more effic

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Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Micro and Nano Material on Critical Heat Flux (CHF) Enhancement
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The Nano materials play a very important role in the heat transfer enhancement. An experimental investigation has been done to understand the behaviors of nano and micro materials on critical heat flux. Pool boiling experiments have used for several concentrations of nano and micro particles on a 0.4 mm diameter nickel chrome (Ni-Cr) wire heater which is heated electrically at atmospheric pressure. Zinc oxide(ZnO) and silica(SiO2) were used as a nano and micro fluids with concentrations (0.01,0.05,0.1,0.3,0.5,1 g/L), a marked enhancement in CHF have been shown in the results for nano and micro fluids for different concentrations compared to distilled water. The deposition of the nano particles on the heater surface was the rea

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Publication Date
Thu Jun 01 2023
Journal Name
Baghdad Science Journal
Design and study the effect of inner bore diameter on the magnetic and optical properties of the unipolar lens
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    Many designs have been suggested for unipolar magnetic lenses based on changing the width of the inner bore and fixing the other geometrical parameters of the lens to improve the performance of unipolar magnetic lenses. The investigation of a study of each design included the calculation of its axial magnetic field the magnetization of the lens in addition to the magnetic flux density using the Finite Element Method (FEM) the Magnetic Electron Lenses Operation (MELOP) program version 1 at three different values of current density (6,4,2 A/mm2). As a result, the clearest values and behaviors were obtained at current density (2 A/mm2). it was found that the best magnetizing properties, the high

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