Aeronautical engineering: A continuing bibliography with indexes, supplement 190

This bibliography lists 510 reports, articles and other documents introduced into the NASA scientific and technical information system in July 1985

A Methodological Approach to Knowledge-Based Engineering Systems for Manufacturing

A survey of implementations of the knowledge-based engineering approach in different technological sectors is presented. The main objectives and techniques of examined applications are pointed out to illustrate the trends and peculiarities for a number of manufacturing field. Existing methods for the development of these engineering systems are then examined in order to identify critical aspects when applied to manufacturing. A new methodological approach is proposed to overcome some specific limitations that emerged from the above-mentioned survey. The aim is to provide an innovative method for the implementation of knowledge-based engineering applications in the field of industrial production. As a starting point, the field of application of the system is defined using a spatial representation. The conceptual design phase is carried out with the aid of a matrix structure containing the most relevant elements of the system and their relations. In particular, objectives, descriptors, inputs and actions are defined and qualified using categorical attributes. The proposed method is then applied to three case studies with different locations in the applicability space. All the relevant elements of the detailed implementation of these systems are described. The relations with assumptions made during the design are highlighted to validate the effectiveness of the proposed method. The adoption of case studies with notably different applications also reveals the versatility in the application of the method

Caractérisations diélectriques, expérimentations ex vivo et simulations multiphysiques de l'hyperthermie micro-ondes des tissus biologiques

Research and development of medical devices with various diagnostic and therapeutic applications have been carried out in different countries because of the great advances in electronic and electromagnetic devices during recent decades. However, at present, all of available existing microwave hyperthermia system can just offer treatment, by using high microwave power. In this thesis, a new microwave hyperemia system is researched which could have both diagnostic and therapeutic functions. One single applicator is used to measure dielectric properties of tissue with a very low harmless microwave power for diagnosis first. Then thermal therapeutic treatment will be carried out by using the same applicator with higher and adapted microwave power. Microwave broad band characterization of five different biological tissues at different temperatures with an open–ended coaxial probe method and the virtual line model has been carried out. Ex vivo microwave hyperthermia experiments using microwave power of a few Watts at 2.45GHz have been carried out on five tissues of various thicknesses. Temperature evolution of the biological tissues has been measured by using an infra-red senor. Electromagnetic and thermal simulations for ex vivo microwave hyperthermia experiment have also been achieved by using COMSOL Multiphysics software with 2D axisymmetrical finite–element method and considering different tissues of various thicknesses and incident microwave powers. Simulation results correlate well with the experimental ones. This research, illustrates the possibility to have a flexible and feasible coaxial cable for both diagnosis and treatment for a minimally invasive therapy.La recherche et développement de dispositifs médicaux avec diverses applications en diagnostiques et en thérapie ont été réalisés. Actuellement, tous les systèmes micro-ondes disponibles d'hyperthermie proposent uniquement des traitements avec une puissance élevée de micro-ondes. Dans cette thèse, un nouveau système d'hyperthermie micro-ondes est étudié pour le bénéfice des fonctions de diagnostic et de thérapie. L'utilisation d'un applicateur avec un niveau très faible et inoffensif de puissance micro-ondes permet de faire le premier diagnostic. Le traitement thérapeutique thermique sera effectué en utilisant le même applicateur avec une puissance micro-ondes élevée et adaptée sur la partie pathologique. Des caractérisations micro-ondes large bande de cinq tissus biologiques différents ont été effectuées à différentes températures avec une méthode de sonde coaxiale ouverte et le modèle de ligne virtuelle. Les expérimentations ex vivo d'hyperthermie micro-ondes avec des puissances de quelques watts à 2,45GHz ont été réalisées sur ces tissus d'épaisseurs variées. L'évolution de la température des tissus a été mesurée en utilisant un capteur infrarouge. Les simulations électromagnétiques et thermiques pour les expérimentations ex vivo d'hyperthermie micro-ondes ont été effectuées en utilisant COMSOL Multiphysics avec la méthode des éléments finis et la symétrie axiale 2D en considérant les tissus variés de différentes épaisseurs et puissances micro-onde incidente. Les simulations du modèle correspondent bien aux mesures. Cette recherche illustre la possibilité d'avoir un câble coaxial souple et adapté à la fois au diagnostic et au traitement pour une thérapie mini invasive

Computational Aspects of Heat Transfer in Structures

Techniques for the computation of heat transfer and associated phenomena in complex structures are examined with an emphasis on reentry flight vehicle structures. Analysis methods, computer programs, thermal analysis of large space structures and high speed vehicles, and the impact of computer systems are addressed

Computer aided stress analysis of the femur with prosthetic hip stem utilizing computed tomography

A computer aided design and analysis method, utilizing computed tomography (CT) is developed, which together with a finite element program determines the stress and deformation patterns in the femur with hip prosthesis. The CT scan data file provides the geometry and the material parameters for the generated finite element model. The three-dimensional finite element model of the femur with hip prosthesis is automatically generated from the CT data file by a preprocessing procedure. The preprocessor includes a CT image display, edge detector, nodes generation, prosthesis simulator, mesh generator and model display. The loading conditions applied on the finite element model are determined from existing gait analysis including joint force and muscle force. Formatted input data for ANSYS (Swanson Analysis Systems Inc.) finite element program is generated by the preprocessor. In this research, the influence on the stress pattern of different prosthetic materials and fixation, such as cobalt-chromium alloy or titanium alloy prosthesis, also cemented or porous-coated prosthesis are studied. A comparison of the stress patterns for the three different femora is made and a radiographic follow-up study in two cases is carried out at 14 months and 12 months postoperation for analyzing the bone remodeling process. As a result of the calculated stress patterns in the femur with prosthesis, it is found that the cobalt-chromium alloy prosthesis unloads the calcar cortical bone and the titanium alloy prosthesis decreases the stress within the prosthetic stem except for the proximal side. The highest calculated stress is approximately 12% of the fatigue limit for cobalt-chromium alloy prosthesis, and approximately 4% for the titanium alloy prosthesis. Comparing the porous coating model with the cemented model, the porous coating model leads to decreased bone stresses, reduced stress concentrations in bone surrounding the prosthesis and more uniformly distributed stress to the surrounding bone tissue. For the effect of stiffness and Poisson\u27s ratio of the porous coating layer, lower elastic modulus and Poisson\u27s ratio will reduce the interface stress between cancellous bone and the porous coating layer. The average stress of the fractured femur with prosthesis is approximately twice the amount of the femur with prosthesis in the proximal and distal side of the prosthetic stem. Furthermore the average stress of the male femur with prosthesis is about 4% lower than the female femur with prosthesis. In regards to stress changes in the postoperative femur, the bone remodeling results indicate that bone resorption of the cortex around the proximal prosthesis would increase the stress in the proximal prosthetic stem and femoral surface slightly while decreasing the stress of the midregion. Bone hypertrophy around the distal prosthesis would decrease the stress up to 35% in the distal prosthetic stem and femoral surface

Mechanical Engineering

The book substantially offers the latest progresses about the important topics of the "Mechanical Engineering" to readers. It includes twenty-eight excellent studies prepared using state-of-art methodologies by professional researchers from different countries. The sections in the book comprise of the following titles: power transmission system, manufacturing processes and system analysis, thermo-fluid systems, simulations and computer applications, and new approaches in mechanical engineering education and organization systems

Seismic Response of Partially Filled Rectangular Liquid Tank With Internal Objects

Sloshing is a phenomenon describing the disturbance in an unrestrained free surface of liquid in a container. It encompasses a wide spectrum of problems of engineering interest. The container in question may be a tea cup, a kerosene jerkin, a water or oil tank, a liquid transporting road tanker, a reservoir or even an ocean. The problem of sloshing is common to all such containers which are partially filled and thus have unrestrained free surface. This dissertation makes a small but honest attempt to study the seismic response of partially filled rigid rectangular tank, with internal objects, firmly supported to the ground. The novelty of this PhD is that it focuses on a special class of container with submerged internal object

Proceedings, MSVSCC 2012

Proceedings of the 6th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 19, 2012 at VMASC in Suffolk, Virginia