The reliability of optical sources is strongly dependent on the degradation and device characteristics are critically dependent on temperature. The degradation behaviours and reliability test results for the laser diode device (Sony-DL3148-025) will be presented .These devices are usually highly reliable. The degradation behaviour was exhibited in several aging tests, and device lifetimes were then estimated. The temperature dependence of 0.63?m lasers was studied. An aging test with constant light power operation of 5mW was carried out at 10, 25, 50 and 70°C for 100hours. Lifetimes of the optical sources have greatly improved, and these optical sources can be applied to various types of transmission systems. Within this degradation range, the device life for system application is estimated to be more than 100 h at 70 ºC at a constant power of 5mW.
Over the last few decades, many instructors have been trying all kinds of teaching methods, but without benefit. Nevertheless, in the 1986, a new technique is appeared which called K-W-L technique, it is specified for reading comprehension passages because reading skill is not easy matter for students for specific purposes (ESP).therefore, the K-W-L technique is a good one for thinking and experiences. To fulfill the aims and verify the hypothesis which reads as follows" it is hypothesized that there are no significant differences between the achievements of students who are taught according to K-W-L technique and those who are taught according to the traditional method
... Show MoreBackground: The rhizome of ginger is used in cooking and for medicinal purposes such as anti-bacterial, anti-fungal, anti-inflammatory and antioxidant. The aims of the study were to test the effect of ethanolic extract of ginger on growth, adherence and acidogenicity of mutans streptococci in comparison to chlorhexidine gluconate 0.2% and de-ionized water. Materials and methods: From saliva often volunteers (dental students 20-22 years); mutans streptococci was isolated, purified and diagnosed according to morphological characteristic and biochemical tests. Ginger was powdered and extracted, different concentrations of ginger extract were prepared. Chlorhexidine gluconate 0.2% used as a control positive; while de-ionized water was used as a
... Show MoreMalaysia will be an ageing population by 2030 as the number of those aged 60 years and above has increased drastically from 6.2 percent in 2000 and is expected to reach 13.6 percent by 2030. There are many challenges that will be faced due to the ageing population, one of which is the increasing cost of pensions in the future. In view of that, it is necessary to investigate the effect of actuarial assumptions on pension liabilities under the perspective of ageing. To estimate the pension liabilities, the Projected Unit Credit method is used in the study and commutation functions are employed in the process. Demographic risk and salary risk have been identified as major risks in analyzing pension liabilities in this study. The sensitivity
... Show MoreThe effect of 5555 strategy on reading comprehension among 4th preparatory students Assist. Prof. Dr. Hassan Khilbas Hammadi College of Education Ibn Rushd – The University of Baghdad Assistant Lecturer. Waleed Khaled Talib Directorate – General For Education Province Of AL - Anbar The purpose of study is to identify the effect of 5555 strategy on reading comprehension among 4th preparatory students. To do this, null hypothesis was postulated. The author hypothesize that there is no a statistically significant difference at (0.05) level between experimental group's scores who study reading comprehension subject following the 5555 strategy and control group's scores who study the same subject following the traditional method in readin
... Show MoreSelenium is naturally present in the human body, animals, and plants, and is one of the important elements in their growth and maintenance. Recently, the nanoform of selenium has attracted attention due to its low toxicity and a high degree of adsorption compared to its organic and inorganic forms. The current study aimed to examine the effect of Cress leaves (Lepidium sativum L.) extract in combination with selenium nanoparticles in alleviating polycystic ovary syndrome in letrozole-induced PCOS in adult female rats. Nonthermal or cold plasma was used in the synthesis of selenium nanoparticles. Subsequently, the produced nanoparticles were identified, the 30 rats were divided into 6 equal groups, the first group was healthy (negative contr
... Show MoreObjective: To evaluate the psychological work environment's effect on the workers’ productivity in Baghdad
City industries at Al-Rusafa and Al-Karkh Sectors.
Methodology: A descriptive evaluation design is employed throughout the present study from May 25th 2012
through January 7
th
, 2014. A purposive (non probability) sample is selected for the study which includes (500)
workers from industries at AL-Russafa and AL-Kerch sectors in Baghdad City. A questionnaire is constructed to
gather data which may assist to achieve the objective of the study. Content validity of the instrument is
determined through eliciting the opinions of a panel of (10) experts and the reliability through a pilot study by
using intern
This intervention study is composed on 55 patients at Saddam Center for Cardiac Surgery (Aben-Albetar) throughout the period from 1st of July 1997 to 15th of January 1999. The study aimed to evaluate the effectiveness of constructed nursing education program on reduction of complications and improving recovery among patients with Coronary Artery Bypass Graft (CABG) surgery through the application of repeated measures. The sample is divided into 27 patients who received the nursing educational program (study group) and 28 patients who continued to receive regular care (controls). Based on previous research meth
Electrospun nanofiber membranes are employed in a variety of applications due to its unique features. the nanofibers' characterizations are effected by the polymer solution. The used solvent for dissolving the polymer powder is critical in preparing the precursor solution. In this paper, the Polyacrylonitrile (PAN)-based nanofibers were prepared in a concentration of 10 wt.% using various solvents (NMP, DMF, and DMSO). The surface morphology, porosity, and the mechanical strength of the three prepared 10 wt.% PAN-based nanofibers membranes (PAN/NMP, PAN/DMF, and PAN/DMSO) were characterized using the Scanning Electron Microscopy (SEM), Dry-wet Weights method, and Dynamic Mechanical Analyzer (DMA). Using DMF as a solvent resulted in a lon
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