The objective of this study is to apply Artificial Neural Network for heat transfer analysis of shell-and-tube heat exchangers widely used in power plants and refineries. Practical data was obtained by using industrial heat exchanger operating in power generation department of Dura refinery. The commonly used Back Propagation (BP) algorithm was used to train and test networks by divided the data to three samples (training, validation and testing data) to give more approach data with actual case. Inputs of the neural network include inlet water temperature, inlet air temperature and mass flow rate of air. Two outputs (exit water temperature to cooling tower and exit air temperature to second stage of air compressor) were taken in ANN.

 مشكلة البحث:

تعد مناهج كليات التربية العمود الفقري لإعداد مدرسين تربويين تقع على عاتقهم مهمة تربية وتعليم الجيل الذي سيتحمل مسؤولية بناء المجتمع وتطويره من خلال بناء وإعداد الأفراد في العديد من المجالات. ولما كان التغيير والتطوير المستمرين هما من السمات المميزة للعصر الذي نعيش فيه لذا تتطلب العملية التربوية مراجعة مستمرة لمناهجها بغية تقويمها وتطويرها بما يتناسب ومت

            In this work, the adsorption of crystal violet dye from aqueous solution on charcoal and rice husk has been investigated, where the impact of variable factors (contact time; the dosage of adsorbent, pH, temperature, and ionic strength) have been studied. It has been found that charcoal and rice husk have an appropriate adsorption limit with regards to the expulsion of crystal violet dye from fluid arrangements. The harmony adsorption is for all intents and purposes accomplished in 45 min for charcoal and 60 min for rice husk. The amount of crystal violet dye adsorbed (0.4 g of charcoal and 0.5 g of rice husk) increased with an increasing pH and the value of 11 is the best

Nine new compounds of 2-amino-5-chlorobenzothiazole derivatives were synthesized. These new compounds were formed through the reaction of 2-amino-5-chlorobenzothiazole 1 with ethyl chloroacetate and KOH, which gave an ester derivative 2, followed by refluxing compound 2 with hydrazine hydrate to afford hydrazide derivative 3. The reaction of compound 3 with CS₂ and KOH gave 1,3,4-oxadiazole-2-thiol derivative 4, and then the reaction of compound 2 with thiosemicarbazide to produce compound 5  then treated it with 4%NaOH led to ring closure to provide 1,2,4-triazole-3-thiol derivative

This paper deals with the modeling of a preventive maintenance strategy applied to a single-unit system subject to random failures.

According to this policy, the system is subjected to imperfect periodic preventive maintenance restoring it to ‘as good as new’ with probability

p and leaving it at state ‘as bad as old’ with probability q. Imperfect repairs are performed following failures occurring between consecutive

preventive maintenance actions, i.e the times between failures follow a decreasing quasi-renewal process with parameter a. Considering the

average durations of the preventive and corrective maintenance actions a

        The current research aims to investigate the skills of the intended meaning beyond the context when reading poetry among fifth literary students. To achieve the aim of the research, the researcher has followed the descriptive approach and used two tools: an open questionnaire that includes an inquiry about the skills of the intended meaning beyond the poetic context, and a closed questionnaire that were examined by the juries, and modified accordingly. Besides, its validity and stability were examined by applying the study on an exploratory sample of (15) teachers to reach its final version and determine the time required to answer it. Then, the researcher applied it on the research sample of (9

The target of this study was to synthesize several new Ciprofloxacin drug analogs by providing a nucleophilic substitution procedure that provides new functionality at the carboxylic group location. The analogs were synthesized, designed, and characterized by ¹HNMR, and FTIR. The synthetic path began from the reaction of ciprofloxacin drug with morpholine to give compound[B], ciprofloxacin derivative was linked with a variety of primary and secondary amines to give compounds[B1-B9]. The above-mentioned prepared compounds [B3 and B5] were applied to liver enzymes, and the increase in the activity of these enzymes was observed. In addition, a theoretical study was conducted to study the energies and properties of the prepared co

لابد لكل باحث في أي موضوع يرغب في عن القارة الافريقية  والمناطق المسلمة منها بشكل خاص ان يتلمس طرق حريتها وتحريرها وانعتاقها علية التحري والبحث عن العقدة الدينية التي عتنقها اهلها والتي جعلت منهم تواقين الى الحرية واثر هذة العقدة على ذلك الانسان في التحرير من كل اشكال العبودية

            The widespread use of the Internet of things (IoT) in different aspects of an individual’s life like banking, wireless intelligent devices and smartphones has led to new security and performance challenges under restricted resources. The Elliptic Curve Digital Signature Algorithm (ECDSA) is the most suitable choice for the environments due to the smaller size of the encryption key and changeable security related parameters. However, major performance metrics such as area, power, latency and throughput are still customisable and based on the design requirements of the device.

The present paper puts forward an enhancement for the throughput performance metric by p

يتضمن البحث طرق تحضير والخواص الكيمائية لمشتقات حلقة 1,3,-4 اوكسادايازول المعوضة في الموقعين 2,5 . كما يتضمن كيفية تحضير بوليمرات بلورية سائلة من المركبات الحلقية غير المتجانسة لحلقة 1,3,-4 اوكسادايازول المعوضة والطرق الطيفية المستخدمة في تشخيص المركبات المحضرة.