Evaluación de un protector antipolvo electrostático de carga automática para aplicaciones de células solares en el clima exterior de Bagdad

Introduction: It is well known that the biggest problem facing the utilizing of solar cell Panels in Baghdad is the unpredictable dusty weather through the days of year. This big problem is not easy to overcome due to the frequent dust accumulations and the high cost of cleaning and other maintenance problems. Dust problems are increasing due to global warming. In Baghdad city, where solar radiation is intense and available almost throughout the year, Deposition of dust on the panels could severely minimize solar-to power output efficiency. There are many methods for dust removing from surfaces like the natural dust removal of wind, mechanical dust removing, super-hydrophobic on solar panel surface, and the electrostatic method which is adopted in this work. The dust particles will be charged statistically by rolling on the surface of the solar panels they will have the same electric charge and the electrostatic forces between them are repulsion. Hence, the dust particles will float away from the solar panels. Materials and Methods: A self-charging transparent conductive glass is prepared by spraying a thin film (141 nm thickness) of a Tin dioxide (SnO2) solution on a glass substrate (12x12 cm2). The dust shield is connected to an electronic charging circuit. The shield is located on the top of a silicon solar cell. The novel idea is that the shield is electrically supplied by the solar cell itself whereas D.C. current from the solar cell itself is used to charge the conductive glass, which is located on the top surface of the cell. Results and Discussion: A test was done for dust removing from a Silicon solar cell by electrostatic repulsion method, considering matching the spectral response region of the Siliconsolar cells with the film transmittance spectral region (400 -700 nm). The transmittance value is between (92 – 95)% and results are compared withan identical reference solar cell. Results show a good response as the calculated clearing factor value increases due to the cell efficiency increment.Also, the clearing factor is discussed as a function of outdoor temperature to show a direct proportionality, while the environmental humidity showed an inverse proportionality. Conclusions: A self-cleaning method for a solar cell is successfully introduced via a conductive glass. tests were carried outdoor in Baghdad city. Results showed that there is a direct proportionality between both: the clearing factor and the efficiency gain with the ambient temperature. The ambient humidity showed indirect proportionality with system efficiency (clearing factor and efficiency gain show reduction as the humidity percentage increases)

The Regenerative Effect of Intra-Articular Injection of Autologous Fat Micro-Graft in Treatment of Chronic Knee Osteoarthritis

The study started in 2010 to find the effect of autologous fat micrograft for osteoarthritis (OA); the result was published on normal animal’s model, in 10 patients, then in 80 patients with knee osteoarthritis, and the current study in 205 patients. The study was conducted at King Abdulaziz University Hospital (January 2012–October 2015); 80 adult patients were suffering from moderate to severe knee osteoarthritis. About 10–20 mL fat micrograft was prepared with liposuction and injected intra-articularly into the affected knee/s. The results revealed that pain improvement after the fat injection during rest and with activity with the visual analogue scale. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) indicated improvement, both in the three domains (pain, stiffness, and physical function) and in total. The use of intra-articular autologous fat micrograft is simple, safe, and effective for degenerative knee osteoarthritis

Influence analysis of director’s elements on the circular Yagi disc antenna performance at 1.8 GHz

This paper aims to investigate and design a Yagi disc antenna with a variable number of director elements for Band 3 in fourth-generation long term evolution (4G LTE) mobile applications. The array technique was introduced by increasing the number of director elements to achieve superior results and better performance, such as higher gain and lower return loss. Initially, the simulated results of return loss and gain with one director element were -19.02 dB and 8.51 dBi, respectively. Then, by increasing the number of directors to three and five elements, the antenna’s performance improved significantly from -32.44 to -42.68 dB for return loss and from 8.51 to 11.17 dBi for gain, respectively. The simulated circular Yagi disc antenna provided a response in the range of 1.78 to 1.82 GHz. Therefore, a model was fabricated and tested to validate the antenna design. The measured results matched well with the simulated ones. By increasing the number of director elements, the measurement results of gain and return loss at a frequency of 1.8 GHz also showed improvement from 7.70 to 11.09 dBi and from -27.31 to -32.91 dB, respectively. Meanwhile, the measured antenna provided a wider bandwidth in the range of 1.72-1.82 GHz

Increasing radiation power in half width microstrip leaky wave antenna by using slots technique

The radiation power in the endfire is decreased while the main beam of half substrate integrated waveguide scan from broadside to endfire in a forward. The design of half-width microstrip leaky-wave antenna (HW-MLWA) has been presented in this work to increase the power radiation near endfire by using the slots technique in the radiation element. This slot leads to a decrease the cross-polarization. The proposed design comprises one element of HW-MLWA with repeated meandered square slots in the radiation element. One aspect of this antenna is generated by using a half substrate integrated waveguide with a full tapered feed line. The proposed antenna was terminated by load of 50 Ω, and feed on the other end of the antenna. Finally, the suggested design is simulated and acceptable results were found. The released gain is increased from 10.6 dBi to 12 dBi at 4.3 GHz. This design is suitable for unmanned aerial vehicle UAVs at C band application

منهجية القنوجي في الترجيح في تفسيره فتح البيان في مقاصد القران

إن المطّلِعَ على كتاب فتح البيان في مقاصد القران للمفسر صديق حسن القنوجي، يجد ففس أمامَ كتابِ وموسوعةٍ ضخمةٍ في دراسات، التفسيرية والفقهيَّة، والحديييَّة في ففس الوقت. حيث، أن مؤلِّفَ قد ألمَّ إلماماً واسعاً بمختلف فنون العلم، أهمّها والحديث ومصطلح ا ولقران وعلوم ا ولفق وأصول واللغة وعلومها؛ نجد كتاب فتح البيان في مقاصد القران، قد أعتنى ب مؤلِّفَ وجمع أفواعاً متعدَّدة من الشرح، لذا نجد أن التعددية من هذه العلوم في كتاب قد جعلت للمفسر منهجية في الترجيح، حيث اتخذ منهجاً خاصاً أتبع في كتاب ، وتتضح منهجية في الترجيح من خلال وجوه الترجيح ، وصيغ الترجيح، وهذا المنهجية نجدها عند كييراً من المفسرين ولكن الذي يميز القنوجي في منهجية اف يستخدم قواعد الترجيح لدى المفسرين ، فيجعلها ميزة لتقوية حجت ، لذا سيبرز الباحث من خلال البحث استقراء و إظهار هذا والمنهجية في الترجيح لدي ، في كتاب فتح البيان في مقاصد القران **************************************************************************** In his life, man follows various ways in his endeavor to research anything which would please him and develop his life socially, scientifically, ethically and behaviorally. Education remains the basis of human development and civilizational construct. Since the time immemorial, man has paid a special attention to educational matters through different methods, and specifically, it received a great attention in the Islamic civilization. We have sought to add the educational matters which could benefit Muslims in particular and non-Muslims in general, based on the most miraculous book witnessed in history, the Noble Qur’an, the last of the revealed scriptures. In an effort to achieve the objectives of this research, the inductive and analytical methods were employed to draw out some educational rules from the Qur’anic chapter called Sūrat Al-Isrā̕ in order to be presented in the form of thesis. The chapter was presented with its exegesis from the authorized books of Tafsīr. Afterwards, substantiated by both the Qur’an and Sunnah, educational rules were deduced. Also, we were keen on having valid inferences far from interpretations and distortions. Moreover, the term ‘rule’ was defined both literally and operationally, as well as its classifications and requirements. The occasion of revelation of the chapter (Sūrat Al-Isrā̕ ) was highlighted. The educational rules which comprise four aspects (worship (Al-̕Ibādah), faith (Al-Īmān), ethics (Al-Akhlāq), and behavior (Al-Sulūq)) were discussed and their effects on individuals and the society. Then, we moved to practical applications in some aspects, shedding light on the contemporary challenges and how they are addressed by the chapter

An ultra-miniaturized MCPM antenna for ultra-wideband applications

In this paper, an ultra-miniaturized modified circular printed monopole (MCPM) antenna is proposed for ultra-wideband (UWB) applications. The proposed antenna consists of four circular discs connected to the structure of the MCPM antenna, which leads to enhancing the antenna impedance bandwidth. The stated MCPM antenna is fed by a coplanar waveguide (CPW) to achieve a 50 impedance matching. A Rogers RT5880 substrate (tan 0.0004 and εr 2.2) is employed for design simulation. The proposed UWB MCPM antenna is designed and simulated for frequencies from 3 up to 11 GHz utilizing computer simulation technology (CST) software. The MCPM antenna is successfully designed and simulated, and its parametric study is performed in a comprehensive way to validate the design novelty. Furthermore, the proposed antenna shows a stable radiation pattern with good gain in the operating band. The stated antenna is also compared with the related literature reviews to differentiate its performance. The total dimension of the finalized antenna is 0.150×0.150×0.00160 that corresponds to the lowest operating frequency of 3 GHz. The finalized MCPM antenna achieves peak gain of 3.2 dB and directivity of 3.9 dBi with high efficiency of 85 % at 11 GHz. Besides, the antenna offers a wide enough bandwidth to be used for UWB and radio communication applications

Failure Data Analysis for Aircraft Maintenance Planning

This paper presents an application of Weibull method for forecasting the failure rate of Boeing 737 Auxiliary power unit (APU) oil pumps. The Weibull method is extremely useful for maintenance planning. Using Weibull failure forecasting, a maintenance planner can make quantitative trades between scheduled and unscheduled maintenance or non-destructive inspection and replacement. The method also helps for determining the age at which an operating part in an aircraft system should be replaced with a new part. In this study, the failure rate of APU oil pump of Boeing 737 aircraft is modeled by using the Weibull technique. The results were in close agreement with the real data indicating the validity of the Weibull model in predicting failure rate of failure for APU oil pumps. In addition, the optimum replacement age of the pumps is also calculated for various cost ratios

Failure Data Analysis for Aircraft Maintenance Planning

This paper presents an application of Weibull method for forecasting the failure rate of Boeing 737 Auxiliary power unit (APU) oil pumps. The Weibull method is extremely useful for maintenance planning. Using Weibull failure forecasting, a maintenance planner can make quantitative trades between scheduled and unscheduled maintenance or non-destructive inspection and replacement. The method also helps for determining the age at which an operating part in an aircraft system should be replaced with a new part. In this study, the failure rate of APU oil pump of Boeing 737 aircraft is modeled by using the Weibull technique. The results were in close agreement with the real data indicating the validity of the Weibull model in predicting failure rate of failure for APU oil pumps. In addition, the optimum replacement age of the pumps is also calculated for various cost ratios

Failure Forecasting of Aircraft Air-Conditioning/Cooling Pack with Field Data

This paper presents methods for modeling the failure of air-conditioning/cooling packs for a particular type of aircraft with field data. In many regards, field data are highly desirable for more accurate failure prediction by aircraft operators, because the data implicitly account for all actual usage and environmental stresses. It is not always possible to accurately anticipate or simulate these stresses in a laboratory or even in a field test. Field data, in a larger extent, are also important to the manufacturer, because the data identify product deficiencies and areas of improvement. In this study, the failure of the aircraft air-conditioning/cooling pack under a customer-use environment is first modeled at the component level by using the Weibull distribution and its extensions. These include the two-parameter Weibull model, three-parameter Weibull model, mixture model, and phased bi-Weibull model. The number of failures over time is estimated by a renewal process. The failure of the air-conditioning/cooling pack at the system level is then modeled by using the power law process model. The failure trend is tested by the Laplace test. The results give an insight into the reliability and quality of the air-conditioning/cooling pack under actual operating conditions. The models presented here can be used by aircraft operators for assessing system and component failures and customizing the maintenance programs recommended by the manufacturer