An experimental investigation of the variation of argon discharge current with a glow and afterglow time intervals of a square discharge voltage was carried out at low pressure (6-11 mbar). The discharge was created between two circular metal electrodes of diameter (7.5 cm), separated horizontally by a distance (10 cm) at the two ends of a Pyrex cylindrical tube. A composite of two Gaussian functions has been suggested to fit and explain the variation graphs clearly. It is shown that the necessary times of glow and afterglow needed to attain a maximum discharge current are (70 us) and (60 us), respectively. The discharge current is observed to drop to the lowest value when the two times are serially longer than (85 us) and (72 us). Furthermore, the difference between the two times required to obtain a maximum rate of change in the discharge current, or a maximum discharge current, is deduced to be comparable to the breakdown time delay of gases reported in the literature. These observations can be useful for the design of plasma devices requiring specialized engineering.
الجمود المؤسسي واثره في فشل التنمية السياسية : محاولة من اجل بناء مفهوم
من اهداف بعض التجارب هي معرفة تاثير التسلسلات المختلفة لبعض الادوية او التغذية او تجارب التعلم. وفي بعض الاحيان قد تكون الوحدات التجريبية نادرة لهذا نقوم باستخدام الوحدات التجريبية على نحو متكرر. او بسبب الميزانية المحدودة فان صاحب التجربة يخضع كل وحدة تجريبية لاختبارات عديدة ويطلق على هذا النوع من التجارب التي يتم فيها استخدام الوحدات التجريبية (الاشخاص) Subject على نحو متكرر
... Show MoreThe Negro minority in the United States is associated with social injustice,
political deprivation, and economic oppresion. Its members felt that they are
second-class citizens, and that the acceptance of such status will lead to the
continual oppresion of the Whites upon them. As a result, the educated community
adopted a process to put a framework to their opposition to the former's injustice.
This organised framework is exemplified in the "Niagara Movement," which is
regarded as the first national organisation for Negros. The topic of this study is
chosen due to its historical and political significance.
The study consists of an introduction and five sections. The first section
addresses the preliminaries an
This study attempts to highlights on the evaluation of performance efficiency for Investments in both National & Iraqi Insurance companies for the years 2001-2010 and their importance on those companies and the economy of the country in order to find out the investment areas and to compare between investment activity and its revenues as well as to compare performance of both companies in investment field.
The study was based on annual reports and balance sheets of both companies. In many chapters, this study dealt with theoretical and practical aspects of the investments and its revenues. Key hypothesis was based on this study, including four parts of Sub hypotheses about (statistical effective relationship between the
... Show Moreتقييم قابلية اداء متطلبات العمل للعاملين في الصناعة باستخدام طريقة القصور الذاتي
The report includes a group of symbols that are employed within a framework that gives a language of greater impact. This research discusses the problem of the semiotic employment of religious symbols in press reports published in the electronic press across two levels: Reading to perceive the visual message in its abstract form, and the second for re-understanding and interpretation, as this level gives semantics to reveal the implicit level of media messages through a set of semiotic criteria on which it was based to cut texts to reach the process of understanding and interpretation.
The report includes a group of symbols that are employed within a framework that gives a language of greater impact. This research discusses the p
... Show MoreThe problem of the present study lies in the challenges that college education especially that concerns the quality of college teachers performance and developing the level of educational process quality.
This study aimed at constructing a vision the researchers have constructed depending on the standards of performance quality represented by Deming's quality course. The researchers presented a number of skills that should be existed in the performance of college teacher through using the analytic and constructing approach in imagining this drawing to develop performance.
The study results represented by a number of efficiencies that college teachers shoul
... Show Moreيعد شعر المنفى احد اهم روافد الادب المعاصر فهو يعكس الإبداع الشعري الحقيقي للشاعر المنفي، ويعكس في الوقت ذاته الحنين والألم الذي يعاني منه بسبب البعد عن وطنه. ومن ناحية أخرى، يصور شعر المنفى حالة المقاومة والنضال التي يختزنها الشاعر . نتناول في هذا البحث م وضوع شعر المنفى عند شاعرين منفيين لم يلتقيا في بلد واحد ولم يتبنيا ثقافة فكرية مشتركة, إلا أن الشاعرين تحملا نفس مرارة المنفى التي عبرا عنها بشكل واضح في شعر
... Show MoreExpired drug Metoclopramide was investigated as an antibacterial corrosion inhibitor for carbon steel in 0.5M H3PO4 solution using the electrochemical method at 30oC and 60oC. The results showed that this drug is an efficient inhibitor for carbon steel and the efficiency reached to 82.244 % for 175 ppm at 30oC and 76.146% for 225 ppm at 60oC. The adsorption of drug on carbon steel surface follows Langmuir adsorption isotherm with small values of adsorption-desorption constant. The polarization plots revealed that Metoclopramide acts as mixed-type inhibitor. Some parameters of inhibition process were calculated and discussed. The surface morphology of the carbon steel speci
... Show MoreBarium–doped TiO2 / n-Si photodetector was fabricated by spray pyrolysis exhibited visible enhancement responsivity profile with peak response at 600 nm flat response between 650 and 900 nm. The quantum efficiency was 30% and specific detectivity was 5x1012 W-1Hz1/2cm at peak response. The GaAlAs laser diode was used to estimate the rise time of the detector.