Behaviour of Grey Cast Iron Under Combined Bending and Tension

This paper deals with the strength of grey cast iron components subjected to combined bending and tension, this case of loading being met in C-frames and clamps, crane hooks and various eccentrically—loaded protruding machine parts. Specimens of rectangular as well as trapezoidal sections, made of flake graphite cast iron, were tested under conditions of eccentric loading. With due consideration of non-linearities and inequalities in stress-strain relations in tension and compression, stress distribution for these sections was obtained from strain measurements. The ratio of bending to tensile stress components is herein shown to play a significant role in locating the neutral plane and in identifying the dominating failure stress. The value 2, for this ratio, is shown to draw some demarkation border between the two modes of fracture encountered in the tests. The apparent superiority of bending strength over tensile strength is herein attributed to the widely differing stress-strain relations in tension and compression

Experimental Investigation of Shock Boundary Layer Interaction for Two-Dimensional and Axisymmetric Flow

A supersonic wind-tunnel has been constructed using an 8 inch by 10 inch single stage jet vacuum ejector with a capacity of handling 0.4 lb/sec air at 4 inches Hg absolute suction pressure. A Toepler Schlieren system with 10-inch diameter parabolic mirrors has been set up for flow pattern visualization. The same apparatus was developed to obtain multi-colored views of the flow pattern. That was accomplished by placing an equilateral prism in front of the light source located at the focal plane of the first parabolic mirror. A spectrum was thus produced at the focal plane of the second parabolic mirror, and the color of the image on the screen could be adjusted by moving a slit (parallel to the bands of the spectrum) across the spectrum. An optical method was developed for visualization of the flow over axisymmetric bodies. A special cylindrical lens test section was designed such that a parallel beam of light coming to one side of the lens would be refracted parallel through its circular cavity and then refracted out parallel on the other side. Using the supersonic tunnel, experiments were conducted on shock boundary layer interaction at low Mach numbers (about 1.3) with two-dimensional as well as axisymmetric models. For the same area ratio the two-dimensional showed severe flow separation from one side but the axisymmetric model showed little or no flow separation both from the pressure data and the optical data. By inserting a plate horizontally, thus dividing the two-dimensional test section into two halves, the severe flow separation was almost eliminated. Although the shock wave is clearly visible when using the optical method for axisymmetric flow, minor flow separation could not be detected using this technique. Theoretical solutions to turbulent incompressible boundary layers for flow over axisymmetric or two-dimensional bodies are well known /1/*. Although these methods area fairly accurate for determining boundary layer growth, the accuracy deteriorates rapidly near the separation point. For the case of compressible flow, the situation in even worse. Thus experimental investigations of compressible boundary layers are needed. A detailed theoretical discussion of compressible boundary layers and shock boundary layer interaction for flow in an axisymmetric inlet is given in Reference 2. The construction of the supersonic tunnel described in this thesis and the testing of several two-dimensional as well as axisymmetric models using this tunnel were made to provide a facility where experimental tests can be conducted on various aspects of flow separation and shock boundary layer interaction

Solution Techniques Based on Adomian and Modified Adomian Decomposition for Nonlinear Integro-Fractional Differential Equations of the Volterra-Hammerstein Type

هذا البحث يطبق بفعاليه طريقه التحليل الادوميانى وطريقه التحليل الادوميانى المعدله كتقنيات عددية لتعيين الحل شبه التحليلى او الحل شبه التقريبى للمعادلات التفاضليه التكامليه اللاخطيه للرتب الكسريه (IFDE) من نوع فولتيرا-هاميرشتين (V-H) والتى توصف فيها المشتقه الكسريه المتعدده العليا بنمط كابوتو. فى هذا النهج سنغير بشكل جذرى ال (IFDE) لنوع  (V-H)  الى بعض معادلات جبريه تكراريه وان الحل لهذه المعادلات هو بمثابه مجموع من المتتابعات اللاعدديه (Countless) لمركبات متقاربه نوعيا للحل المستند (المعتمد)  على الحدود الضوضائيه وذلك فى حاله عدم حصولنا على حل من النوع المغلق وان الحدود المقطوعه (المحذوفه) يستخدم للاغراض العدديه. واخيرا تم اعطاء امثله لتوضيح هذه الافكار والاعتباراتThis paper efficiently applies the Adomian Decomposition Method and Modified Adomian Decomposition Method as computational techniques to locate the semi-analytical solution or semi-approximate solution for the considered nonlinear Integro Differential Equations for the fractional-order (IFDE) of the Volterra-Hammerstein (V-H) type, in which the higher-multi fractional derivative is described in the Caputo sense.In this procedure, we radically change the IFDE’s of V-H type into some iterative algebraic equations and the solution of this equations is considered as the sum of the countless sequence of components typically converging to the solution based on the noise terms where a closed-form solution is not obtainable, a truncated number of terms is usually used for numerical purposes.Finally, examples are prepared to illustrate these considerations

Magnetostatic surface waves on left-handed materials (LHM)

The nonlinear characteristics of magnetostatic surface waves at microwave frequencies in a layered structure of left-handed material film and a semi-infinite linear ferrite substrate have been investigated. The general dispersion relation is derived and analyzed numerically. It is found that it has two solutions for ω (k), one represents a physical solution and other unacceptable. The effects of the applied external magnetic field around the proposed region have also been examined

Laplace Adomian Decomposition and Modify Laplace Adomian Decomposition Methods for Solving Linear Volterra Integro-Fractional Differential Equations with Constant Multi-Time Retarded Delay

     في هذا العمل نقدم تحويلات لابلاس مع طريقة أدوميان التحليلية المتسلسلة و كما اننا نعدل طريقة أدوميان التحليلية للمرة الاولى لحل معادلات فولتيرا التفاضلية-التكاملية الخطيه للرتب الكسرية كما في مفهوم كابوتو مع التأخير الحدي المتضاعف الثابت. هذه الطريقة تعتمد على مزيج ممتاز من طريقة تحويلات لابلاس، طريقة تحديد المتسلسلات، طريقة متعددات الحدود لادوميان مع التعديلات. أن التقنية المستخدمة تحول التأخير الحدي للمعادلات التفاضلية ذات التكاملات الكسرية الى معادلات جبرية متكررة عندما تكون نواة الفروق من نوع المنحل البسيط. و أخيراَ أعطيت أمثلة لتوضيح فعالية و ديقة الطرق المقترحة.In this work, we present Laplace transform with series Adomian decomposition and modify Adomian decomposition methods for the first time to solve linear Volterra integro-differential equations of the fractional order in Caputo sense with constant multi-time Retarded delay. This method is primarily based on the elegant mixture of Laplace transform method, series expansion method and Adomian polynomial with modifications. The proposed technique will transform the multi-term delay integro-fractional differential equations into some iterative algebraic equations, and it is capable of reducing computational analytical works where the kernel of difference and simple degenerate types. Analytical examples are presented to illustrate the efficiency and accuracy of the proposed methods

Internet of Bio Nano Things-based FRET nanocommunications for eHealth

The integration of the Internet of Bio Nano Things (IoBNT) with artificial intelligence (AI) and molecular communications technology is now required to achieve eHealth, specifically in the targeted drug delivery system (TDDS). In this work, we investigate an analytical framework for IoBNT with Forster resonance energy transfer (FRET) nanocommunication to enable intelligent bio nano thing (BNT) machine to accurately deliver therapeutic drug to the diseased cells. The FRET nanocommunication is accomplished by using the well-known pair of fluorescent proteins, EYFP and ECFP. Furthermore, the proposed IoBNT monitors drug transmission by using the quenching process in order to reduce side effects in healthy cells. We investigate the IoBNT framework by driving diffusional rate models in the presence of a quenching process. We evaluate the performance of the proposed framework in terms of the energy transfer efficiency, diffusion-controlled rate and drug loss rate. According to the simulation results, the proposed IoBNT with the intelligent bio nano thing for monitoring the quenching process can significantly achieve high energy transfer efficiency and low drug delivery loss rate, i.e., accurately delivering the desired therapeutic drugs to the diseased cell