The development of magnox fuel cans at the Heston Laboratories of A.P.C. Ltd. required a non-contact method of measuring fuel can temperature during heat transfer tests. Infra-red techniques were examined and a two colour ratio pyrometer was selected as offering the greatest prospect of success. A design specification was compiled for an instrument having a lower temperature limit of 250°C with a target area of approximately 1mm². During heat transfer tests a pressurised rig is used and an observation window is necessary. This leads to some deterioration in performance which it is impracticable to remove by internal chopping and the pyrometer is designed for outside use. Operational wavebands around 1.8 and 2.3 microns are chosen and a lead sulphide infra-red detector operating at room temperature is selected. The properties of the detector lead to a design where the signal is chopped at 900 cps and modulated at 30 cps by the energy in each waveband. Conventional optical systems are considered and rejected in view of the large size of chopper wheel necessary. An alternative system is devised in which a commercially available pencil galvanometer is used to combine the function of chopping at both 900 cps and 30 cps. This enables an optical system to be designed which, because it employs reflecting optics, is compact and for the most part axially symmetric. The signal ration is extracted using an automatic gain control technique and a high signal to noise ratio is achieved with a phase sensitive rectifier at the output. The pulses which activate the galvanometer chopper and phase sensitive circuits are derived from a master oscillator operating at 900 cps. The performance of the system is assessed and it meets the specification in all respects except for a small surface geometry effect. The underlying cause for this is examined and a means for overcoming it is suggested. The performance when scanning a magnox can during bench tests is illustrated and it can be seen that although agreement to within 2°C is obtained with thermocouples placed at the fin roots, the geometry effect prevents the isolation of fin tip temperature. During the development of the instrument the possibility of wider application was an important consideration. Some of the applications which have arisen are discussed briefly and an indication of the performance of the pyrometer is given. Furthermore the system is capable of easy modification for use with a cooled detector and other regions of the infra-red spectrum.

Thesis. 1976. B.S.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Microfiche copy available in Archives and Engineering. / Includes bibliographical references. / B.S.

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2004. / Habetler, Thomas, Committee Member ; Sadegh Nader, Committee Member ; Taylor David, Committee Member ; Tsiotras Panagiotis, Committee Co-Chair ; Heck-Ferri Bonnie, Committee Co-Chair. Vita. Includes bibliographical references (leaves 319-326).

Conceptual design is a vital part of the design process during which designers first envision new ideas and then synthesize them into physical configurations that meet certain design specifications. In this research, a computational approach is developed to assist the designers perform this non-trivial task of navigating the design space for creating conceptual design configurations. The methodology is based on combining empirical reverse engineering techniques with a graph-grammar approach. Accordingly, design knowledge is systematically extracted from past designs, formulated as procedural grammar rules, and employed in building new design concepts. The implemented system provides a theoretical framework for automatically searching conceptual design spaces and produces novel alternative configurations to real design problems. The application of the approach to the design of various electromechanical devices shows the method's range of capabilities, and how it serves as a comparison to human conceptual design generation and as a tool to complement the skills of a designer.

Thesis (M.Phil.)--University of Hong Kong, 2003. / Includes bibliographical references. Also available in print.

Orientador: Marcos César de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-30T18:19:25Z (GMT). No. of bitstreams: 1 DoriguelloDiniz_JoaoFernando_M.pdf: 5802868 bytes, checksum: 75d67be6662dcc05e681b956a5848b12 (MD5) Previous issue date: 2016 / Resumo: Passeios quânticos são a contrapartida quântica aos passeios aleatórios clássicos e têm um papel crucial no desenho de algoritmos quânticos eficientes que superam algoritmos clássicos. Durante os últimos anos, um grande esforço tem sido feito para implementar passeios quânticos experimentalmente, principalmente unidimensionais. Entretanto, implementações experimentais de passeios quânticos em duas dimensões ainda são escassas, e é justamente a partir de duas dimensões em que há algum ganho computacional. Este projeto parte desta necessidade para propor um sistema físico capaz de implementar um passeio quântico bidimensional: um qubit superconductor acoplado capacitivamente a um oscilador mecânico. Este sistema já foi estudado anteriormente e mostrou-se ser capaz de reproduzir um passeio quântico unidimensional. O projeto centrou-se então em generalizar este sistema acoplamento um segundo oscilador mecânico ao qubit e em demonstrar que o sistema assim obtido é capaz, teoricamente, de gerar um passeio quântico bidimensional. Foram conduzidas simulações da distribuição de probabilidade do sistema sem e com decoerência. Além disso, estudamos a recente relação entre mecânica quântica relativística e passeios quânticos; mais especificamente, revisamos a semelhança entre as equações de Klein-Gordon e Dirac e as equações de evolução do passeio quântico / Abstract: Quantum walks are the quantum counterpart to classic random walks and have a crucial role in the design of efficient quantum algorithms that overcome classic algorithms. During the last years a great effort has been dedicated to implement quantum walks experimentally. However, bi-dimensional quantum walk implementations are still scarce and it is precisely starting from two dimensions that there exists some computational gain. This dissertation is based on this necessity to propose a physical system capable of implementing a two-dimensional quantum walk: a superconducting qubit capacitively coupled to a mechanical oscillator. This system has already been studied in the literature and was shown to adequately generate a one-dimensional quantum walk. The dissertation was thus centred in generalizing this system by coupling a second mechanical resonator to the qubit and in demonstrating that this resulting system is theoretically capable of simulating a two-dimensional quantum walk. Simulations of the probability distribution with and without decoherence were conducted. Moreover, we studied the recent connection between relativistic quantum mechanics and quantum walks; more specifically, we revised the resemblance between the Klein-Gordon and Dirac equations and the quantum walk time evolution equations / Mestrado / Física / Mestre em Física / 2014/12617-5 / FAPESP

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Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Orthodontics is the eld of dentistry concerned with the treatment of maloc- clusion and anomalies of the dento-facial complex. This thesis is concerned with studying the underlying biomechanical principles of orthodontic tooth movement. It aims to develop a novel treatment approach and an orthodontic appliance to facilitate said approach by employing advanced technologies. A thorough review of the literature is used to form a comprehensive knowledge base pertaining to the factors a ecting orthodontic tooth movement. It is hypothesised that an electromechanical orthodontic appliance could improve treatment by characterising orthodontic cases based on the relationship be- tween the applied mechanical stimulus and the resulting changes to the af- fected structures, which can then be sensed by the appliance. A prototype is built using electronically controllable linear actuators and a custom built force transducer system for measuring orthodontic forces. Electronic circuits are de- veloped to connect the appliance to a USB port and allow it to be controlled from a graphical user interface (GUI). This further facilitates real-time viewing of important orthodontic parameters. Experiments are carried out to evaluate the appliance functionality with regard to the proposed hypothesis. To con- clude, the relevance of the results to the orthodontic eld is highlighted and recommendations for further development of an electromechanical orthodontic appliance are provided. / AFRIKAANSE OPSOMMING: Ortodonsie is die vakgebied in tandheelkunde gemoeid met die behandeling van wanpassing en abnormaliteit van die tand- en gesig-area. Hierdie tesis bestudeer die onderliggende biomeganiese beginsels van ortodontiese tandbeweging om sodoende 'n nuwe benadering sowel as 'n ortodontiese apparaat te ontwikkel om die genoemde benadering te fasiliteer deur gebruik te maak van gevorderde tegnologie. 'n Deeglike oorsig van die literatuur word gebruik om 'n omvattende kennisbasis op te bou rondom die faktore wat ortodontiese tandbeweging a ekteer. Die hipotese word gestel dat 'n elektromeganiese ortodontiese apparaat behandeling kan verbeter deur ortodontiese gevalle te identi seer/- karakteriseer gebaseer op die verhouding tussen die toegepaste meganiese stimulus en die gevolglike veranderinge aan die gea ekteerde strukture wat deur die apparaat aangevoel word. Elektronies-beheerbare lineêre aandrywers en 'n pasgemaakte krag-oordraerstelsel vir die meet van ortodontiese kragte word gebruik om 'n prototipe te vervaardig. Elektroniese stroombane word ontwikkel om die apparaat te koppel aan 'n USB poort sodat dit beheer kan word d.m.v. 'n gra ese gebruikerskoppelvlak. Eksperimente poog om die apparaat funksioneel te evalueer volgens die voorgestelde hipotese. Ter afsluiting: die toepaslikheid van die verwerfde resultate in die ortodontiese vakgebied word beklemtoon en aanbevelings word gemaak vir toekomstige/verdere ontwikkelings m.b.t. 'n elektromeganiese ortodontiese apparaat.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 75-77. / by Bradley L. Hunter. / M.S.

This thesis describes studies of a two-dimensional (2D), hexagonal arrangement of carbon atoms, graphene. Because of graphene’s reduced dimensionality, the 2D material possesses many desirable mechanical and electrical properties compared to its three-dimensional (3D) counterpart, graphite. In fact, its mechanical strength and electrical mobility are one of the strongest and fastest in the world, prompting much excitements from science and engineering communities alike ever since its first experimental demonstration in 2004. The first part of this thesis deals with graphene in material level. Chapter 1 provides an introduction to graphene. Chapter 2 describes chemical vapor deposition (CVD) synthesis of graphene and various transfer techniques. Chapter 3 describes characterization of graphene using optical inspection, oxidation test, Raman spectroscopy, and electrical transport. The second part of this thesis concerns graphene in device level, electro-mechanical implementation in particular. Chapter 4 gives an introduction to graphene nano-electro- mechanical systems (GNEMS), where the material’s mechanical and electrical prowess can best be combined, and describes fabrication process as well as transduction mechanism. Chapter 5 shows how GNEMS can be used to build a pressure sensor or an accelerometer. Chapter 6 is a study of the graphene resonators for signal processing such as in RF filters or oscillators. Chapter 7 describes the graphene - silicon nitride heterostructure resonators. The third part of this thesis considers the integration of GNEMS at a system level. Chapter 8 depicts integration of graphene resonators onto a taped-out CMOS die using post-processing. This work, in conjunction with numerous other work done by fellow researchers in the field, tries to provide an overview - from the material synthesis to device fabrication and characterization, and further to system level integration - in utilizing graphene, and graphene NEMS in particular, for sensing and signal processing applications.