Artificial roughness applied to a Solar Air Heater (SAH) absorber plate is a popular technique for increasing its total thermal efficiency (ηt−th). In this paper, the influence of geometrical parameters of V-down ribs attached below the corrugated absorbing plate of a SAH on the ηt−th was examined. The impacts of key roughness parameters, including relative pitch p/e (6–12), relative height e/D (0.019–0.043), angles of attack α (30–75°), and Re (1000–20,000), were examined under real weather conditions. The SAH ηt−th roughened by V-down ribs was predicted using an in-house developed conjugate heat-transfer numerical model. The maximum SAH ηt−th was shown to be 78.8% as predicted under the steady-state condition

The selection and assessment of single-photon detection modules is a crucial problem in satellite-based QKD systems. The system's overall efficiency, secure key rate and quantum bit error rate are all significantly influenced by single-photon detection modules. There is a knowledge gap about the practical performance of commercially available single-photon detectors because existing research frequently relies on theoretical characteristics. This paper introduces a study on the effect of the parameters of three commercial single photon detection modules from ID Quantique company: ID Qube, ID100, and ID281 on certain Bennett-Brassard 1984 protocol parameters such as secure key rate, mean photon number per pulse, quantum bit error rate

In this paper, the Azzallini’s method used to find a weighted distribution derived from the standard Pareto distribution of type I (SPDTI) by inserting the shape parameter (θ) resulting from the above method to cover the period (0, 1] which was neglected by the standard distribution. Thus, the proposed distribution is a modification to the Pareto distribution of the first type, where the probability of the random variable lies within the period  The properties of the modified weighted Pareto distribution of the type I (MWPDTI) as the probability density function ,cumulative distribution function, Reliability function , Moment and  the hazard function are found. The behaviour of probability density function for MWPDTI distrib

Abstract

A new type of solar air heater was designed, fabricated, and tested in Baghdad, Iraq winter conditions. The heater consists of two main parts. The horizontal section was filled with the black colored iron chip while the vertical part has five pipes filled with Iraqi paraffin wax. A fan was fixed at the exit of the air. Two cases were studied: when the air moved by natural convection and when forced convection moved it. The studied air heater has proven its effectiveness as it heated the air passing through it to high temperatures. The results manifest that using little air movement makes the temperatures, stored energies, and efficiencies of the two studied cases converge

٠ اش١جخ ٗزفقث ٌٟبِ ٟجعبؾٌّا تٔبغٌا ٟف بقزخِ ٟئبنل ( ًئاضل بساحم ) توهم ىلع ءىضلا طٍلسحو بلارم ءادأ ىلع اهرٍثأحو تٍوهملا اهحاءارجإو تمذخخسملا اهحاٍومح ثٍح نم تٍئاضملا تبساحملا دبثبغؾٌا . اسبِٙٚ د ءبمٌلأ ٟمبٌّا ـؾف ٍٝػ ض١وشزٌا يلاخ ِٓ خ١ٔٛٔبمٌا سِٛلأبث خفشؼٌّا ءٛم ٟف دب٠شؾزٌا ًجمزغٌّا ٍٝػ حشظٔ ٌا خجعبؾٌّا ْا شؽبجٌا ظزٕزعاٚ ذٍجٌٍ ٞدبقزللاا َذمزٌا خٍغػ غفد ٟف ُٙغر خ١ئبنم ، خجعبؾٌّا ٟف خِذخزغٌّا خض٠ذؾٌا ت١ٌ

dance that reflect deferent sides from life human , in this search ensure for the causation can the expressionistic dancing be development acting actor in Iraqis theatre ? so this search concept of section one composed of the search problem  , and important  the search  and need it , aimed the search , lines search it composed of the lines time ,  place , and lines subject , and the searcher ended this section with practical terms .   Section tow – theatrical lines form that composed of part one the dance kinds: the expressionistic dancing, is very important in analyses the symbol .                     

مشكلة البحث

       لقد حدا بالمهتمين في الميدان التربوي، والادارة التربوية بصورة خاصة، ان يجدوا علاقات ايجابية بين متغيرات الميدان التربوي عامة والاداري بصورة خاصة وقد تمخض هذا عن وجود علاقة ايجابية بين اداء المديرين ورؤساء الاقسام ودرجة التقويم، ومن هنا يتضح انه كلما كان التقويم عالياً في درجته، يتضح ان هناك اداءً فاعلاً ولكن ليس بالشكل الحقيقي لمعنى التقويم ما لم يكن هناك

 The research aims to study the entrepreneurial performance of the banks, according to the intelligence of competitive and strategic as the entrepreneurial performance is the one who does not stand the benefits of excellence in accomplished when just achieving the bank's objectives planned, but exceed it down to creativity in accomplishing these goals in a manner leads to making a entrepreneurial bank in the markets and the focus the eyes of competitors and the banks and other Following his example.

Was chosen the subject of research and strategic intelligence and competitive because of its impact on the strategic success of the banking sector, the fact is the entrepreneurial in the Iraqi banking mar

This book includes four main chapters: 1. Indefinite Integral. 2. Methods of Integration. 3. Definite Integral. 4. Multiple Integral. In addition to many examples and exercises for the purpose of acquiring the student's ability to think correctly in solving mathematical questions.

Changes in mechanical properties of material as a result of service in different conditions can be provided by mechanical testing to assist the estimation of current internal situation of these materials, or the degree of deterioration may exist in furnaces serviced at high temperature and exceed their design life. Because of the rarity works on austenitic stainless steel material type AISI 321H, in this work, ultimate tensile strength, yield strength, elongation, hardness, and absorbed energy by impact are evaluated based on experimental data obtained from mechanical testing. Samples of tubes are extracted from furnace belong to hydrotreaterunit, also samples from un-used tube material are used to make comparisons between these properti