The ceramic compound Mg1-xSixAl2O4 (x= 0, 0.1, 0.2, 0.3, 0.4) was prepared from nano powder of Al2O3 and MgO doped with Nano powder of SiO2 at different molar ratios. The specimens were prepared by standard chemical solid reaction technique and sintered at 1450 oC. Structure of the specimens was analyzed by using X-ray diffraction (XRD). The X-ray patterns of the specimens showed the formation of pure simple cubic spinel structure MgAl2O4 phase with space group of ̅ . The average grain size and surface topology were studied by atomic force microscopy. The results showed that the average grain size was about 73-90 nm. The DC electrical properties of the specimen were measured. The apparent density was found to increase and the porosity and water absorption were found to decrease with increase of Si addition. Mechanical properties were characterized by Vicker’s micro hardness and Brazilian fracture test to measure the fracture toughness of the samples. The micro hardness decreased with Si addition increase. Fracture toughness increased with the increase in Si addition.
The current research aims to know the extent of the impact of performance evaluation in its dimensions as an explanatory variable in the behavioural and attitudinal work outputs with its dimensions as a response variable in order to reach appropriate solutions through which the University of Fallujah seeks to achieve its goal in the process of diagnosing the axes of strength and to benefit from them in the process of strengthening the status and sobriety of the academic position of the professor and the researcher relied on The descriptive and analytical approach in carrying out this study, and data was collected from university professors, including leaders, heads of departments and divisions, who numbered (97) teachers. And fie
... Show MoreIn this paper, the effect of temperature on the charge transfer rate of dye (N3) in contact with ZnS semiconductors is discussed and studied when electrons move from the excited N3 dye to the conduction band of ZnS based on quantum shift theory. In a heterogeneous system, the energy levels are assumed to be continuous, and the N3-ZnS system is surrounded by a variety of polar solvent media. The transition energy of the N3/ZnS heterojunction was calculated using seven different solvents at room temperature, considering the refractive index and dielectric constant of the solvents and the ZnS semiconductor, respectively. The charge-transport reaction rate was calculated over different te
The research aims to measure the impact of the quality of the audit on the Earnings Quality, for a sample of private joint stock companies listed on the Iraq Stock Exchange, as the research sample included (14) private and listed joint stock companies in issuing their financial statements for the period from (2010-2018), as well as companies The audit offices in charge of auditing these companies, which number (18) companies or an audit office, and the research relied on two main models for measurement, as the first model reflects the assumed relationship between independent variables represented in the characteristics of external audit quality and measuring the extent of its impact on the dependent variable represented in the Ea
... Show MoreThis study has aimed to measure the relationship between the skills required for the labor market and the employment of graduates of community colleges at King Khalid University. For gathering the required data, a questionnaire has been designed and distributed to the faculty members of community colleges at King Khalid University in a random sample method. The chosen sample size has covered (123) individuals. Questionnaire forms have been distributed and retrieved from (117) participants. Therefore, the estimated response has reached 95 % of the total sample size. The results of the study have shown that there is not any significant relationship between the skills which the graduates acquire and the requirements of employmen
... Show MoreThat the structural changes in the environment, business and finance and the spread of business and the diversity of transactions between economic organizations and breadth of a commercial scale in the world have left their clear on the need to keep up with the accounting for these variables as one of the social sciences affect and are affected by the surrounding environment because of the various economic and social factors, technical, legal and others.
As a result of these variables emerged a new field of accounting called Forensic Accounting, which involves the use of expertise of multiple pour in the end to the accounting profession, where the Forensic Accounting cover a large area of disciplines including strengthening
... Show MoreIn this research, Zinc oxide (ZnO)/epoxy nanocomposite was synthesized by simple casting method with 2wt. % ZnO concentration. The aim of this work was to study the effect of pH and composite dosage on the photocatalytic activity of ZnO/ epoxy nanocomposite. Scanning electron microscopy (SEM) technique images proof the homogeneous distribution of ZnO nanoparticles in epoxy. A synthesized nanocomposite samples were characterized by Fourier Transform Infrared spectrometer (FTIR) measurements. Two spectra for epoxy and 2wt.% ZnO/epoxy nanocomposites were similar and there are no new bonds formed from the incorporation of ZnO nanoparticles. Using HCl and NaOH were added to Methylene blue (MB) dye (5ppm) to gat pH values 3 and 8. The degradat
... Show MoreBackground: Celiac disease is an autoimmune chronic disease that affects the human’s intestine and subsequently reflects its effect on the entire body health by retardation the absorption and immune mediated complications cause the involvement of oral health. The present study intended to evaluate the impact of the histopathological disease activity upon dental enamel defects and dental caries.
Subjects and methods: Forty celiac-diseased patients aged 7-11 years were collected from 3 different teaching hospitals in Baghdad classified by means of the histopathological activity of the intestinal disease according to modified Marsh-Ros
... Show MoreBackground : It had been indentified by histological, histochemical and morphometrical studies that peganum harmala is a mammogenic herb and borage officinalis is a lactogenic one . To complete our investigation about these two herbs , we performed electron microscopical study . Materials and methods : Rats were grouped according to their physiological status into three groups . Each group was subdivided in to three subgroups : one control and two experimental . The two experimental group were treated daily; the 1st one with an aqueous extract of peganum harmala seeds and the 2nd with an aqueous extract of borage officinalis flowers . After two weeks of treatment , mammary glands were employed for electron microscopical study . Resu
... Show MoreHyperthyroidism or thyrotoxicosis occurs due to excess release of thyroid hormone. These hormones regulate the body’s energy balance and have effects on adipokine level. There are several reports suggesting interrelation between adipokines (resistin and leptin) with thyroid dysfunction. Objectives: This study was established to investigate the effect of thyroid hormones in hyperthyroidism state on the level of some adipokines, leptin and resistin; in comparison with control. Patients and Methods: The present study included 50 Iraqi female patients with hyperthyroidism with age ranged between 30-58 years and 30 healthy controls with age ranged between 30-53 years. Serum samples were collected from study groups. The levels of thyroid hormon
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