The effects of using aqueous nanofluids containing covalently functionalized graphene nanoplatelets with triethanolamine (TEA-GNPs) as novel working fluids on the thermal performance of a flat-plate solar collector (FPSC) have been investigated. Water-based nanofluids with weight concentrations of 0.025%, 0.05%, 0.075%, and 0.1% of TEA-GNPs with specific surface areas of 300, 500, and 750 m2/g were prepared. An experimental setup was designed and built and a simulation program using MATLAB was developed. Experimental tests were performed using inlet fluid temperatures of 30, 40, and 50 °C; flow rates of 0.6, 1.0, and 1.4 kg/min; and heat flux intensities of 600, 800, and 1000 W/m2. The FPSC’s efficiency increased as the flow rate and hea

In this paper, several combination algorithms between Partial Update LMS (PU LMS) methods and previously proposed algorithm (New Variable Length LMS (NVLLMS)) have been developed. Then, the new sets of proposed algorithms were applied to an Acoustic Echo Cancellation system (AEC) in order to decrease the filter coefficients, decrease the convergence time, and enhance its performance in terms of Mean Square Error (MSE) and Echo Return Loss Enhancement (ERLE). These proposed algorithms will use the Echo Return Loss Enhancement (ERLE) to control the operation of filter's coefficient length variation. In addition, the time-varying step size is used.The total number of coefficients required was reduced by about 18% , 10% , 6%

The research studies the main variables for the concept of sharing in knowledge in one of the most important control agencies in Iraq, which is (The Federal Board of Supreme Audit). Also, the quality of the controlling businesses by the Board in light of the major challenges that facing the fight against signs of cheating and administrative and financial corruption for offices submitted to controlled and auditing, with the increasing and intensification of these appearances. In order to enable the Board to cope with this situation, has to be thinking hard about how to achieve excellence, progress and development to face these situations, through the application of sharing in knowledge for the financial controller, and then achiev

المقدمة

تتعامل الجهات الضريبية في مختلف دول العالم بأساليب عديدة لجباية الضرائب من المكلفين بغض النظر عن فئات وأصناف هؤلاء المكلفين،وفي العراق تم اعتماد العديد من الأساليب لجباية الضرائب على امتداد المدد الزمنية المتعاقبة،وكان لأسلوب التقدير الذاتي وهو أحد تلك الأساليب مجالاً للتطبيق خلال مدة زمنية معينة،حيث جرى تطبيق هذا الأسلوب على وحدات اقتصادية معينة، وبالرغم من المساوئ التي قد ترافق تطبيق

This research aims at identifying the level of quality of University environment according to the viewpoint of female students taking the College of Sciences for Woman an example, as represented in the college units as registration unit and the unit of students' affairs, the curricula, instructors, study halls, the college library, scientific labs, computer access, stationary and photocopying services, health care center, the unit of artistic, cultural and sportive activity, the canteen, the college gardens, college buildings and equipment and bathrooms. To achieve the objectives of the research, the researcher prepared a questionnaire to identify the viewpoints of female students concerning the extent of the availability of the standards o

This paper study two stratified quantile regression models of the marginal and the conditional varieties. We estimate the quantile functions of these models by using two nonparametric methods of smoothing spline (B-spline) and kernel regression (Nadaraya-Watson). The estimates can be obtained by solve nonparametric quantile regression problem which means minimizing the quantile regression objective functions and using the approach of varying coefficient models. The main goal is discussing the comparison between the estimators of the two nonparametric methods and adopting the best one between them

The response of the combustor’s liner to the air-flow that passes through it is the key reason for the combustion chambers noise, hence the instabilities of those chambers that decreases the mechanical efficiency of such sections, by increased its mechanical vibrations, which increases the failure rate created during originating of the cracks spreading by the shakes producing by the series of high-level frequencies. Accordingly, any work debating the impact of the context of liners in the combustion chamber can provide grasping for the combustion noise generated by the undesirable vibrations, and benefits the industrial firms to design an ideal production procedure which increases the lifespan of the combustor. The goal of this work is