505 research outputs found

    Fractional Ostrowski type inequalities for functions whose derivatives are s-preinvex

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    In this paper, we establish a new integral identity, and then we derive some new fractional Ostrowski type inequalities for functions whose derivatives are s-preinvexpeerReviewe

    Enhancing magnetic particle testing of automotive parts

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    The principle disadvantage in magnetic particle inspection, as generally practiced today, is the combination of variable human judgment and interpretation, and variations in the critical components' characteristics which are: magnetic particle liquid sensitivity, ultraviolet intensity variations, and magnetic field variations at the surface of the test piece. In high speed inspection systems, these variables can reduce the reliability of magnetic particle inspection flaw detection to only about 70% [I]. What is needed is an online, heavy duty, high speed parts inspection with online documentation and almost perfect flaw detect ability within calibrated equipment, if possible, by using modem electronic systems. Currently, the automated MT systems are still in their first stages and are developed on individual researchers' basis [2]. Also, the few current systetns in the market which can automatically perform magnetic particle testing are extremely expensive. Hence, the need to provide a reasonable automated MT system with a comparable performance for inspecting surface defects in ferromagnetic materials automotive component

    Quranic motivation toward modern approach for e-Da'wah

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    The world today need to know Islam correctly. In our days there are more than five billion people who do not believe in Islam all over the world

    Analytical Study and Modeling of Free Vibrations of Functionally Graded Plates Using a Higher Shear Deformation Theory

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    In this paper, we have used an analytical method to analyze the vibratory behavior of plates in materials with gradient of properties, simply supported, proposing a refined non polynomial theory. The number of unknown functions involved in this theory is only four, as compared to five in the case of other higher shear deformation theories. The transverse shearing effects are studied according to the thickness of the plate. The motion equations for the FGM plates are obtained by the Hamilton principle application, the solutions are obtained using the Navier method, and then the fundamental frequencies are found, solving an eigenvalue equation system, the results of this analysis are presented and compared to those available in the literature

    Regression analysis of masked competing risks data under cumulative incidence function framework

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    In the studies that involve competing risks, somehow, masking issues might arise. That is, the cause of failure for some subjects is only known as a subset of possible causes. In this study, a Bayesian analysis is developed to assess the effect of risks factor on the Cumulative Incidence Function (CIF) by adopting the proportional subdistribution hazard model. Simulation is conducted to evaluate the performance of the proposed model and it shows that the model is feasible for the possible applications

    Some new Hermiteโ€“Hadamard type inequalities for functions whose nth derivatives are convex

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    We first create an integral identity for n-times differentiable functions. Relying on this identity, we establish some new Hermiteโ€“Hadamard type inequalities for functions whose nth derivatives are convex

    Electrically active defects in novel Group IV semiconductors.

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    This thesis presents the electrical characterisation of defects in novel group IV semiconducting materials: semiconducting diamond and silicon germanium (SiGe) virtual substrates. Several methods to clean diamond surfaces are introduced, which lead to the fabrication of a diamond Schottky diode with acceptable characteristics. Current-Voltage (I-V) and Capacitance-Voltage (C-V) measurements were carried out to study the electrical properties of both the diamond and SiGe Schottky diodes. Deep level transient spectroscopy (DLTS) and Laplace DLTS were then carried out to investigate the deep electronic states in these devices. Scanning Electron Microscopy (SEM) was also used to investigate defects in the diamond samples. For the diamond Schottky diodes, I-V and C-V measurements confirmed the quality of the fabricated Schottky diode; the measured phase angle between capacitance and voltage was close to 90° for temperatures greater than 300K and frequencies above 200 kHz and the device clearly exhibited rectification. DLTS and LDLTS measurements of the diamond did not show any signatures that could be attributed to isolated point defects. This could be due to the fact that it was necessary to take the samples to higher temperatures in order to fully ionize the boron in the sample. The boron acceptor is at 0.37 eV above the valence band and therefore only about 5% is ionised at room temperature. During the major part of the study at Manchester, there was no access to a high temperature cryostat. However, a clear capacitance transient was observed at lower temperatures and it is proposed that this is due to emission of holes from boron. Deep traps will be located deeper in the band gap than the boron. An additional problem was that the sample was of polycrystalline structure and is full of grain boundaries, which appear to be implicated in the leakage currents present in our devices. I-V, C-V, DLTS and LDLTS were also used to investigate the deep states in the SiGe virtual substrate. I-V and C-V measurements showed that the SiGe Schottky diode showed some leakage (reported by the suppliers) but nevertheless the diode exhibited rectification. Analysis of the DLTS data showed the presence of a defect in the SiGe samples which could be a structural defect, probably dislocation-related. However, the low background doping meant that a considerable depth below the surface was being measured in DLTS and depth profiling was not possible
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