813 research outputs found

    Experimental Results of a Wind Energy Conversion System with STATCOM Using Fuzzy Logic Controller

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    This paper describes a complete implementation of the experimental voltage regulation of a wind energy conversion system using STATCOM. Firstly conventional control technique is used which is proportional plus integral controller. The control technique is performed using a PC computer through a suitable interfacing and opt-isolating facilities. Secondly fuzzy logic controller is facilitated in this scheme to improve the performance of the experimental setup. Several efforts are done to choose the suitable gains of the fuzzy controller to achieve superior performance of the wind system. Experimental results of the system show the effectiveness of the proposed technique in regulating the output voltage. Thanks to the operation of the STATCOM in controlling the reactive power of the system to fix the output voltage at the desired value regardless of the wind speed

    Experimental Results of a Wind Energy Conversion System with STATCOM Using Fuzzy Logic Controller

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    This paper describes a complete implementation of the experimental voltage regulation of a wind energy conversion system using STATCOM. Firstly conventional control technique is used which is proportional plus integral controller. The control technique is performed using a PC computer through a suitable interfacing and opt-isolating facilities. Secondly fuzzy logic controller is facilitated in this scheme to improve the performance of the experimental setup. Several efforts are done to choose the suitable gains of the fuzzy controller to achieve superior performance of the wind system. Experimental results of the system show the effectiveness of the proposed technique in regulating the output voltage. Thanks to the operation of the STATCOM in controlling the reactive power of the system to fix the output voltage at the desired value regardless of the wind speed

    Geochemical and biomarker characteristics of crude oils and source rock hydrocarbon extracts: An implication to their correlation, depositional environment and maturation in the Northern Western Desert, Egypt

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    AbstractOil–oil and oil–source rock correlations are used in this study in order to achieve their relationship, depositional environments and diagenetic processes in the source rocks. Three oil samples and source rock hydrocarbon extracts were analyzed using relative geochemical analyses, and gas chromatography–mass spectrometry are used for this purpose. The results revealed that the extracts of the Alam El Bueib and Khatatba formations are derived from mixed organic sources in which terrestrial dominates marine sources, and deposited in transitional environments under less anoxic conditions. The extracts of Bahariya formation are derived from mixed marine inputs with a limited terrestrial contribution. The Alam El Bueib oil shows more contribution of terrestrial than marine sources. Also, a genetic close relation between them supported the indigenous mixed source of Alam El Bueib oil which related to different sources including the Khatatba, Alam El Bueib and Bahariya formations. Accordingly, the Alam El Bueib formation can be considered as an important source for petroleum generation in the Northern Western Desert

    First occurrence of the ant genus Brachymyrmex Mayr, 1868 (Hymenoptera: Formicidae) from the Kingdom of Saudi Arabia

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    The formicine ant genus Brachymyrmex Mayr, 1868 is recorded for the first time from the Kingdom of Saudi Arabia and from the Arabian Peninsula by the species B. cordemoyi Forel, 1895. A brief description and automontage images of the species are presented with ecological and biological notes

    Upcycling Used Garments to Recreate Sustainable Fashion Designs Treated by Soil Release Finishing

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    Upcycled garments can have that independent appeal. No matter whom the designer is or what styling options designers choose, these upcycled fashion garments and accessories are by nature one-of-a kind. Finishing of textile fabric is carried out to increase attractiveness and/or serviceability of the fabric. Different finishing treatments are available to get various effects, which add value to the basic textile material, which can be better solutions for sustainable fashion. The sustainable fashion was achieved to a certain extent by using available materials to its ultimate USAge, using waste material, recycling of the products, planning second life for the fashion product, slowing down the fashion etc. The main idea to do so is to develop more sustainable and responsible designs. This paper is not just about recycled clothes but about fashion, recycling, upcycling, adding value and uniqueness by the resulting one-of-a-kind design available for women to purchase in any retail store. Create nine designs using waste garments treated by soil release finishing agent as a source of sustainable fashionable designs

    Haren: A Framework for Ad-Hoc Thread Scheduling Policies for Data Streaming Applications

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    In modern Stream Processing Engines (SPEs), numerous diverse applications, which can differ in aspects such as cost, criticality or latency sensitivity, can co-exist in the same computing node. When these differences need to be considered to control the performance of each application, custom scheduling of operators to threads is of key importance (e.g., when a smart vehicle needs to ensure that safety-critical applications always have access to computational power, while other applications are given lower, variable priorities).Many solutions have been proposed regarding schedulers that allocate threads to operators to optimize specific metrics (e.g., latency) but there is still lack of a tool that allows arbitrarily complex scheduling strategies to be seamlessly plugged on top of an SPE. We propose Haren to fill this gap. More specifically, we (1) formalize the thread scheduling problem in stream processing in a general way, allowing to define ad-hoc scheduling policies, (2) identify the bottlenecks and the opportunities of scheduling in stream processing, (3) distill a compact interface to connect Haren with SPEs, enabling rapid testing of various scheduling policies, (4) illustrate the usability of the framework by integrating it into an actual SPE and (5) provide a thorough evaluation. As we show, Haren makes it is possible to adapt the use of computational resources over time to meet the goals of a variety of scheduling policies

    Measuring Impact of Air and Agricultural Soil Pollution on Social Development in Saudi Arabia

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    This research aimed to measure the impact of air and agricultural soil pollution on social development in Saudi Arabia from the period 1995–2019 by using social development indicators, concentrating on the percentages of expenditure on education and health, and the Human Development Index. In addition, this study uses multiple regressions in estimating the model to study the impact of air pollution and agricultural soil on social development. Results of the study showed that a 10% change in the number of chemical fertilizers and pesticides used in Saudi agriculture leads to a change in the total number of inpatients by 0.7% and 0.5%, respectively. It was also found that an increased percentage of health expenditure to total government spending by 10% leads to a decrease in the total number of patients in the hospital by 1.8%. An increase in air pollution, expressed as a 10% increase in CO2 emissions, increases the total number of hospitalized patients by 11.1%.  The increasing total number of patients by 10% leads to a decrease in the total productivity of the worker, as an indicator of 1.8%. Furthermore, a change of 10% in the ratio of education expenditure to total government expenditure leads to a change in the same direction of the Human Development Index by 9.6%. In light of these results, it can be recommended that the country need to reduce air pollution by expanding the use of natural gas in the industrial and transportation sectors, in addition to reducing the use of nitrogenous fertilizers and pesticides in Saudi agriculture through the expansion of clean farming and good agricultural practices

    Review of the ant genus Technomyrmex Mayr, 1872 in the Arabian Peninsula (Hymenoptera, Formicidae)

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    The taxonomy of the dolichoderine ants of the genus Technomyrmex Mayr, 1872 is revised for the Arabian Peninsula. Six species are treated, T. albipes (F. Smith, 1861), T. difficilis Forel, 1892, T. briani Sharaf, 2009, T. vexatus (Santschi, 1919), T. montaseri Sharaf, Collingwood & Aldawood, 2011, and T. setosus Collingwood, 1985. The successful tramp species T. difficilis Forel, 1892 is recorded for the first time from the Kingdom of Saudi Arabia (KSA) and Yemen, representing new records for the Palearctic Region. Technomyrmex vexatus (Santschi, 1919) is a new species record for Yemen. The queen caste of the rare endemic species, T. briani Sharaf, 2009 is described for the first time. A neotype for KSA endemic T. setosus Collingwood 1985 is designated based on a specimen collected from the type locality, the Asir Mountains, KSA, including new information on habitats and distribution. A male cast of Technomyrmex, possibly of T. setosus, is also described. An illustrated key based on the worker caste of the Arabian species of Technomyrmex is given. New geographical records and a distribution map for the treated species are presented

    Electrical Response of CdS Thin Film and CdS/Si Heterojunction to Gamma Radiation

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    Gamma irradiation method has been used to change the electrical properties of CdS thin film. A specific dose of γ-irradiation increases the activation energy of CdS thin film. In addition, γ-irradiation was used to change the sign of Hall coefficient, RH, of CdS thin film from negative to positive irrespective of temperature. The Hall mobility mechanism shows noticeable change after γ-irradiation from decreasing to increasing with raising the temperature. In depth, analysis was done using capacitance-voltage measurement in order to realize the modification in the CdS/Si junction band gap after γ-irradiation. Several parameters were also studied such as charge carrier concentration, ND, and flat band potential, Vfb. The γ-irradiation was found to increase the concentration of the deep traps within the band gap of the CdS/Si heterojunction
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