Natural convection in a trapezoidal enclosure with partial heating from below and symmetrical cooling from the sides has been investigated numerically. The heating is simulated by a centrally located heat source on the bottom wall, and four different values of the dimensionless heat source length, 1/5, 2/5, 3/5, 4/5 are considered. The laminar flow field is analyzed numerically by solving the steady, two-dimensional incompressible Navier-Stokes and energy equations. The Cartesian velocity components and pressure on a collocated (non-staggered) grid are used as dependent variables in the momentum equations discretized by finite volume method; body fitted coordinates are used to represent the trapezoidal enclosure, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The range of Rayleigh number is (103≤ Ra ≤105) and Prandtl number is 0.7. The results show that the average Nusselt number increases with the increases of the source length.
The university professor is the main theme in the educational process, then we must have prepared attention and study, it is the upper hand in achieving the objectives of education and a factor of development of society and its development factors that set it up and increase the efficiency of the duties of universities and development centers and through that evaluation is essential process and Zerorah to improve his performance, especially if they're the evaluation process from the standpoint of their students
research goals
The current research aims to identify:
1. identify the effectiveness of teaching the University of Tikrit from the standpoint of their students
2. to identify the differences in
على الرغم من تحقق ثورة هائلة وطفرة نوعية في مجال تكنلوجيا الاتصالات في دول العالم الا ان بلدنا كان محروما من التمتع بهذه التقنيات الحديثة في ظل النظام السابق, وبعد سقوط النظام ووجود بحبوحة من الحرية، دخلت الكثير من هذه التقنيات الى العراق ومنها الموبايل والانترنيت وغيرها من وسائل الاتصال المتطورة.
ويقول (Smith & Fletcher, 2001) في كتابهما Inside Information
... Show MoreThe Islamic orthodox caliphs had a great importance in the history of Arabs in
particular, and of Muslims in general.
Some attributed poetry to them. This issue to see whether such an attribution is correct
or not.
This research tried to deal objectively with this poetry .it discussed the topic,
exploring the scholars’ opinions about poetry attributed to the Islamic orthodox
Caliphs, stating their dispute : some of them agreed while others rejected the
attribution.
The research adopted the opinon that had rejected for reasons stated in the
research, of them: the weakness of poetry and its dealing with unimportant things, for
example, the caliph Omar composed verses about a new garment worn by him.
Is it
تتركز مشكلة البحث في ضعف كثير من المربين معلمين كانوا أو مدرسين في التعامل مع أخطاء المتعلمين في ضوء السنة النبوية مما يؤدي إلى تعلم غير منتظم، ومن أهم أسباب هذه المشكلة قلة الإطلاع على الأساليب العملية التي ينبغي أن يتعامل بها المربي مع أخطاء المتعلمين، ولا سيما الأساليب المستمدة من القرآن الكريم والسنة النبوية، وهذا ما لمسه الباحث واقعاً من خلال ممارسته لعملتي التعليم والتدريس لمدة خمس عشرة سنة، ومن خ
... Show MoreThis paper deals with defining Burr-XII, and how to obtain its p.d.f., and CDF, since this distribution is one of failure distribution which is compound distribution from two failure models which are Gamma model and weibull model. Some equipment may have many important parts and the probability distributions representing which may be of different types, so found that Burr by its different compound formulas is the best model to be studied, and estimated its parameter to compute the mean time to failure rate. Here Burr-XII rather than other models is consider because it is used to model a wide variety of phenomena including crop prices, household income, option market price distributions, risk and travel time. It has two shape-parame
... Show MoreThe objective of the study is developing a procedure for production and characterization of rice husk ash (RHA). The effects of rice husk (RH) amount, burning/cooling conditions combined with stirring on producing of RHA with amorphous silica, highest SiO2, lowest loss on ignition (LOI), uniform particle shape distribution and nano structured size have been studied. It is concluded that the best amount is 20 g RH in 125 ml evaporating dish Porcelain with burning for 2 h at temperature 700 °C combined with cooling three times during burning to produce RHA with amorphous silica, SiO2 90.78% and LOI 1.73%. On the other hand, cooling and stirring times affect the variation of nano structured size and particle shape dis
... Show Moreت لا نم ظ او ره لا يأ لاح اهلاح رضاحلا رصعلا يف ةريطخ ه ةوشرلا لثم ةيداصتقا ةميرج ديعصلا ىلع ةيبلس بقاوع اهل يتلاو زازتبلااو لاوملأا لسغو ني ىلا ةجاحلا تءاج انه نم ، يداصتقلااو يعامتجلاا تاسسؤم لبق نم اهينبت يغبني يرادلإاو يلاملا داسفلا نم دحت تامدخو بيلاسأو تاينقت ةيلاملا مئارجلا نم دحلل ةلودلا اع ىلع عقت يتلا تاسسؤملا نمو ةيئاصقتسلاا ةبساحملا وا ةيئاضقلا ةبساحملاب تلثمت ةيداصتقلاا تادحولا يف ينبت اهقت ة
... Show MoreThe current research aimed to investigate the psychometric characteristics of the Arabic version of the Nomophobia scale for the Omani youth. The scale was administered to a random sample of students from public and private universities and colleges in Oman. The research sample consisted of 2507 students, of whom 868 males and 1639 females. The validity of the measure was first checked by presenting the scale to a group of experts in this field. Then the exploratory and confirmatory factor analysis was carried out. The exploratory factor analysis revealed the existence of three main factors: the fear of connectivity loss, the fear of communication loss with others, and the fear of network outages. These factors accounted for 65.6% of the
... Show MoreFaintly continuous (FC) functions, entitled faintly S-continuous and faintly δS-continuous functions have been introduced and investigated via a -open and -open sets. Several characterizations and properties of faintly S-continuous and faintly -Continuous functions were obtained. In addition, relationships between faintly s- Continuous and faintly S-continuous function and other forms of FC function were investigated. Also, it is shown that every faintly S-continuous is weakly S-continuous. The Convers is shown to be satisfied only if the co-domain of the function is almost regular.
In the current digitalized world, cloud computing becomes a feasible solution for the virtualization of cloud computing resources. Though cloud computing has many advantages to outsourcing an organization’s information, but the strong security is the main aspect of cloud computing. Identity authentication theft becomes a vital part of the protection of cloud computing data. In this process, the intruders violate the security protocols and perform attacks on the organizations or user’s data. The situation of cloud data disclosure leads to the cloud user feeling insecure while using the cloud platform. The different traditional cryptographic techniques are not able to stop such kinds of attacks. BB84 protocol is the first quantum cry
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