5,263 research outputs found

    Notched graphite polymimide composites at room and notched graphite polymide composites at room and elevated temperatures

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    The fracture behavior in graphite/polyimide (Gr/PI) Celion 6000/PMR-15 composites was characterized. Emphasis was placed on the correlation between the observed failure modes and the deformation characteristics of center-notched Gr/Pl laminates. Crack tip damage growth, fracture strength and notch sensitivity, and the associated characterization methods were also examined. Special attention was given to nondestructive evaluation of internal damage and damage growth, techniques such as acoustic emission, X-ray radiography, and ultrasonic C-scan. Microstructural studies using scanning electron microscopy, photomicrography, and the pulsed nuclear magnetic resonance technique were employed as well. All experimental procedures and techniques are described and a summary of representative results for Gr/Pl laminates is given

    Anovel Immunological Technique for Identification of Human Seminal Fluid

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    An immunological technique was investigated for the detection of human semen in forensic analysis.This technique included a preparation of anti-human seminal plasma antibodies, by immunizing rabbits with treated human semen. The human semen was treated with an acid to prevent cross reactivity with other human body fluids. The antibody produced was tested against different animal,s seminal fluid samples (dog, goat ,sheep, cow) and human body fluids( saliva, blood , vaginal fluid, ear wax and human semen). It was found that using this developed technique was only selectively responsed with human semen . The prepered kit was evaluated and tested in Forensic laboratory- Ministry of Health. Finally, results were obtained in a comparison with the recommended techniques

    Building an Agile, Competitive and Dynamic Entrepreneurial Ecosystem to Create a Startup Culture, Startup Nation, and a Startup Region: Case of Egypt and the MENA Region

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    In today’s economic, business and social spaces, communities and societies around the world constantly face a set of challenges related to growing unemployment, economic development, changing market dynamics and tough business conditions amongst others. However, these societies and spaces are also regularly presented with a variety and spectrum of opportunities, given the continuous development of new markets, the growing role of cutting-edge technology platforms, especially with the growing penetration and impact of the fourth industrial revolution, the evolution of the digital economy and the global widespread of entrepreneurial initiatives and activities around the world in both the developed world and in emerging economies

    Pre- and post-processing for Cosmic/NASTRAN on personal computers and mainframes

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    An interface between Cosmic/NASTRAN and GIFTS has recently been released, combining the powerful pre- and post-processing capabilities of GIFTS with Cosmic/NASTRAN's analysis capabilities. The interface operates on a wide range of computers, even linking Cosmic/NASTRAN and GIFTS when the two are on different computers. GIFTS offers a wide range of elements for use in model construction, each translated by the interface into the nearest Cosmic/NASTRAN equivalent; and the options of automatic or interactive modelling and loading in GIFTS make pre-processing easy and effective. The interface itself includes the programs GFTCOS, which creates the Cosmic/NASTRAN input deck (and, if desired, control deck) from the GIFTS Unified Data Base, COSGFT, which translates the displacements from the Cosmic/NASTRAN analysis back into GIFTS; and HOSTR, which handles stress computations for a few higher-order elements available in the interface, but not supported by the GIFTS processor STRESS. Finally, the versatile display options in GIFTS post-processing allow the user to examine the analysis results through an especially wide range of capabilities, including such possibilities as creating composite loading cases, plotting in color and animating the analysis

    Some Properties of Chaotic Modified of Bogdanov Map

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    In this  research to the modified dynamics of Bogdanov's map  studied, and the  found sensitivity to the initial conditions of the modified map  found as well as the Lyapunov exponent .the general characteristics of the map  by the diffeomorpism. Finally we boosted my research  with matlab to find chaotic area

    Potentiometric detection of low-levels of sulfamethazine in milk and pharmaceutical formulations using novel plastic membrane sensors

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    Novel potentiometric sensors for selective screening of sulfamethazine (SMZ) in pharmaceutical preparations and milk samples are reported. The sensor membranes were made from PVC matrix doped with magnesium(II)-, manganese(II)- and dichlorotin (IV)-phthalocyanines as ionophores and aliquat-336 and nitron/SMZ ion-pair complex as ion exchangers. These sensors revealed fast, stable and near-Nernstian anionic response for the singly charged sulfamethazine anion over the concentration range 10-2 - 10-5 M. The sensors exhibited good selectivity towards SMZ over most known anions, excipients and diluents commonly added in drug preparations. Validation of the proposed methods was demonstrated via evaluating the detection limit, linear response range, accuracy, precision (within-day repeatability) and between-day-variability. The sensors are easily interfaced with a double channel flow injection system and used for continuous monitoring of SMZ in drug formulations, spiked milk samples and biological tissues. The method offers the advantages of design simplicity, results accuracy, and automation feasibility

    Improvement of Water Quality in a Highly Polluted River in Jordan

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    Zarqa River is considered one of the most important sources of surface water in Jordan. The construction of Al-Samra wastewater treatment plant has caused a considerable deterioration in water quality of that river and pollution of the groundwater of that basin. This paper aims to study the change in water quality in the river by applying hydraulic and quality models. Samples of wastewater from the inlet and outlet of the plant were collected and analyzed according to the standard methods. The obtained results concerning BOD, NH4 and DO were used as input to predict water quality in the river. For this purpose, a one dimensional quality model has been developed to simulate pollutants transport in the river. The model was constructed to represent the change in concentrations of such parameters in the river from the treatment plant to the King Talal dam. 296 quality samples and 90 hydraulic samples were taken in order to calibrate the model. Results indicate that the concentrations of BOD, COD and NH4 effluent from the plant exceeded the allowable limits according to Jordanian standards. From the results of simulation, it is found that the model is applied successfully to predict water quality in Zarqa River. Due to self purification, high reduction of pollutant concentrations occur along the river .The concentration of BOD is still higher than the allowable limit until 33 km downstream of the plant, while NH4 concentration is higher than the standards in all reaches

    An active buffer management technique for providing interactive functions in broadcast video-on-demand systems

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    Multicast delivery is an efficient approach to the provision of a video-on-demand (VoD) service. Interacting with the video stream is a desirable feature for users. However, it is a challenging task to provide the functionality in the multicast environment because a lot of users share multicast delivery channels. In this paper, we propose an active buffer management technique to provide interactive functions in broadcast VoD systems. In our scheme, the client can selectively prefetch segments from broadcast channels based on the observation of the play point in its local buffer. The content of the buffer is adjusted in such a way that the relative position of the play point is kept in the middle part of the buffer. Our simulations show that the active buffer management scheme can implement interactive actions through buffering with a high probability in a wide range of user interaction levels. © 2005 IEEE
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