Abstract Rasha Hameid Jehad Baghdad University Background: The high reactivity of hydrogen peroxide used in bleaching agents have raised important questions on their potential adverse effects on physical properties of restorative materials. The purpose of this in vitro study was to evaluate the effect of in-office bleaching agents on the microhardness of a new Silorane-based restorative material in comparison to methacrylate-based restorative material. Materials and method: Forty specimens of Filtek™ P90 (3M ESPE,USA) and Filtek™ Supreme XT (3M ESPE, USA) of (8mm diameter and 3m height) were prepared. All specimens were polished with Sof-Lex disks (3M ESPE, USA). All samples were rinsed and stored in incubator 37˚C for 24 hours in DDW. Ten sample of each material were subjected to 37.5% hydrogen peroxide gel (Pola office +, SDI)for 8 minutes while exposed to light curing device, this step was repeated three times for 3 weeks. While the other ten samples for each material was served as control. All specimens were subjected to microhardness test using digital microhardness tester to determine the VHN (Vickers Hardness Number) Results : The Filtek™ P90 exhibited higher microhardness value than Filtek™ Supreme XT. After hydrogen peroxide treatment, both types of composites exhibited low microhardness values but still Filtek™ P90 is harder than Filtek™ Supreme XT. Conclusion : In-office hydrogen peroxide bleaching agent resulted in reduction in microhardness values for both composite materials. Silorane- based composite is more affected by the bleaching agent than methacrylate-based composite.
Obesity is a common disease that resulted from over-nutrition in adults and children. It rarely causes damage to the centers of food in the brain. Obesity is defined as an increased body weight from its natural limit which is resulted from the accumulation of excessive amounts of fatty tissue incredibly up to 20% in males, 30 % in females unless this increase is not due to an increase in muscles as in athletes or accumulation of water in the body which is resulted from Mesothelioma or the magnitude of the skeleton.Obesity is the increase of the total average of fat in the body compared to other tissues, which causes an increasing body weight, thereby increasing body mass. The fatty child has an increase in the stored fatty layer under th
... Show MoreNumerous research studies have been conducted on why some learners acquire a second language more easily and quickly than others. Most of these studies have demonstrated that acquiring a second language does not depend only on learners’ cognitive ability or professional teaching strategies. The learning language process is more complicated than that. It is affected by crucial factors that are beyond the control of learners and teachers. These factors are known as sociolinguistic factors. These factors include culture, age, motivation, socio-economic status, and gender. This research paper mainly concentrates on the role of motivation in second language acquisition.
The spectral response of the Si solar cell does not coincidence with the sun irradiance spectrum, so the efficiency of the Si solar cell is not high. To improve the Si solar cell one try to make use of most region of the sun spectrum by using dyes which absorb un useful wavelengths and radiate at useful region of spectrum (by stock shift). Fluorescence's dye is used as luminescent concentrator to increase the efficiency of the solar cell. The results show that the performance efficiency and out power for crystalline silicon solar cells are improved.
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Buzurgan oil Field which is located in south of Iraq has been producing oil for five decades that caused production to drop in many oil wells. This paper provides a technical and economical comparison between the ESP and gas lift in one oil well (Bu-16) to help enhancing production and maximize revenue. Prosper software was used to build, match and design the artificial lift method for the selected well, also to predict the well behavior at different water cut values and its effect on artificial lift method efficiency. The validity of software model was confirmed by matching, where the error difference value between actual and calculated data was (-1.77%).
The ESP results showed the durability of ESP regarding th
... Show MoreIndividual cannot live alone due to to his need for others to facilitate His supplies for living, thus social affiliation is considered one of the most important psychological, social needs in individuals life through his willing to affiliate to others whether they were friends ,family, colleague , or even home to reach some degree of psychological stability.
Affiliation is a tool to search for Satiate through living with group from the same type or comply for group or to be compatible with them or even to be adherent and accept what the group agreed about of criterion.
 
... Show MoreAll the available reports on the issue of infertility confirmed the increase in this population problem worldwide. Although the accurate estimate of the number of infertile people is due to several reasons, including the discrepancy in the true definition of infertility (whether it extends for one, two or five years of failed pregnancy attempts), as well as the great discrepancy in the size of the selected population groups (large population sample size versus epidemiological studies) and defining the category that diagnosed included (individuals, women, or couples). The goal of today’s IVF program is to obtain high-quality embryos with high efficiency in development, which leads to an increase in live birth rates.
In the present paper, three reliable iterative methods are given and implemented to solve the 1D, 2D and 3D Fisher’s equation. Daftardar-Jafari method (DJM), Temimi-Ansari method (TAM) and Banach contraction method (BCM) are applied to get the exact and numerical solutions for Fisher's equations. The reliable iterative methods are characterized by many advantages, such as being free of derivatives, overcoming the difficulty arising when calculating the Adomian polynomial boundaries to deal with nonlinear terms in the Adomian decomposition method (ADM), does not request to calculate Lagrange multiplier as in the Variational iteration method (VIM) and there is no need to create a homotopy like in the Homotopy perturbation method (H
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Cultural and identity scars have been engraved in the body of ethnic minority of Muslims in America due to the bloody attacks of 9/11. These events have created thus traumatic experiences on the party who witnessed the events at close and the people on whom the blame is conclusively directed, Muslim Americans. For Americans, the attacks resulted in a proud reassertion of the national virtue and communal integrity from which Muslim Americans were excluded. This reassertion is accompanied for Muslims by a reconstruction of a cultural identity away from their origin homeland and under pressures and prejudices that made the process of reconstruction to be severely challenging. Accordingly, the challenge needed to be portrayed to overcome the d
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Beta-lactamase was purified from local isolate Klebsiella pneumonia by several steps included precipitation with ammonium sulphate at 20-40% saturation, DEAE- ion exchange chromatography and gel filtration on Sephacryl S-200 column. The obtained purification fold and recovery were 32.66; 47.04% respectively. The characterization of the purified beta-lactamase showed that the molecular weight was about 4000 daltons as determined by gel filtration.Purified enzyme had an optimal pH of 7 for activity and an optimal stability between pH 6.5-7.5, results shows that the optimal temperature appear to be 35 ? C .During storage the enzyme retained 72% at -20 ? C and retained 25% of the activity at the same period at 4 ? C.