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Rangharajan, Kaushik Krishna. "Engineering Electromechanical Systems to Regulate Nanoscale Flows." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1524140747281763.
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Chu, Angela (Angela J. ). "Prototyping practices in electromechanical startups." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92604.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (page 24).<br>Electromechanical startups contend with signicant uncertainty, especially in early stages of development. Prototyping is a critical component through the product development process, and when employed eciently, can act as a method for mitigating risk associated with product viability for founders and funders. While extensive research has been conducted on prototyping practices in industry, there has been little investigation into prototyping for electromechanical startups. This research aims to understand current prototyping practices in these environments by answering the following questions. What kinds of prototypes do startups develop? What functions do these prototypes serve? What are the relevant traits that make these prototypes conducive to these functions? To develop a formal questionnaire, preliminary interviews with two startups were conducted. A case study was also conducted of prototyping practices in 2.009 Product Engineering Processes, an undergraduate course at MIT. Following this, secondary interviews were held with members of three additional startups. From a sample of 52 identied prototypes, relationships were found between the material categorizations of prototypes and three key functional roles: test, clarify, and communicate. To further understand the prototyping choices of startups, material categorizations were evaluated with respect to eight core prototype characteristics. Results show that prototypes favored for testing were physically interactive, such as 3D sketches or digitally fabricated models. Inexpensive and easy-to-alter representations (2D sketches, 3D sketches, and CAD) were created to clarify concepts. Visually appealing models (CAD, 2D sketches) were used heavily for both internal and external communication.<br>by Angela Chu.<br>S.B.
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Yaglioglu, Onnik 1976. "Carbon nanotube based electromechanical probes." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40357.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.<br>Includes bibliographical references (p. 131-137).<br>Electromechanical probing applications continuously require smaller pitches, faster manufacturing and lower electrical resistance. Conventional techniques, such as MEMS based cantilever probes have their shortcomings in terms of the lowest pitch that can be achieved, cost and yield. Given their promising mechanical and electrical properties, carbon nanotubes (CNTs) are strong candidates for future probing applications. A new class of metal-CNT hybrid electromechanical probes is presented where vertically aligned carbon nanotube structures, grown with a chemical vapor deposition (CVD) technique, act as elastic springs, and a metal coating on the probes is used for increased electrical conduction. This design and architecture presents a scalable approach where thousands of probes can be fabricated in very short production times. 1.5 Ohm resistance and reliable performance for 6000 cycles at 50 [mu]m over-travel was achieved for a column of 200 [mu]m x 200[mu]m cross-section and 1plm of Au deposition. In-situ scanning electron microscope mechanical compression tests revealed a unique deformation mechanism of the CNT structures where continued compression results in successive buckle formation which later can serve as micro-bellows and elastic springs.<br>(cont.) A novel stiffness tuning method is presented to control the elastic properties of a given CNT probe by controlling the initial compressing amount. Further stiffness tuning is achieved by changing gas composition during CVD growth where CNT diameter and density is modified. Lateral compression and densification tests show that these CNT structures are highly anisotropic and have very different deformation mechanisms in vertical and lateral directions. Mechanical properties resulting from two main CVD growth techniques, namely fixed catalyst where a thin film of catalyst layer is deposited onto the growth substrate, and floating catalyst where the catalyst particles are introduced in the gas phase, are compared. It is found that floating catalyst CVD growth yields much stiffer structures due to the relatively larger CNT diameters. As the adhesion of CNT structures to the growth substrate is very weak and the support layer is typically an insulator, a versatile transfer printing technique is developed which enables simultaneous placement and reinforcement of the probes on a wide range of substrates, including metals and printed circuit boards. Electromechanical performance and failure mechanisms of fully functional metal-CNT hybrid probes are presented.<br>by Onnik Yaglioglu.<br>Ph.D.
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Wilhelm, Eric Jamesson 1977. "Printed electronics and micro-electromechanical systems." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/27141.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.<br>Includes bibliographical references.<br>Current electronics and micro-electromechanical systems (MEMS) manufacture is optimized for the production of very high-volume parts on a limited range of substrates. These processes are long, consume large amounts of resources, and require expensive machines and facilities, but yield excellent products. Cheaper, faster printing processes are beginning to emerge with the ability to economically produce low or high-volume electronics and MEMS on flexible substrates. This thesis describes the theoretical and practical design of a suite of printing processes including liquid embossing and offset liquid embossing (OLE). These printing techniques have created resistors, capacitors, and thin-film transistors without etching, vacuum deposition, or high temperatures. Here, the fabrication of all-printed electrostatic actuators is described In liquid embossing a polydimethylsiloxane (PDMS) stamp with bas-relief features is brought into intimate contact with a thin liquid film such as a metal or semi-conductor nanoparticle colloid, spin-on-glass, or polymer to create patterns as small as 100 nm. A simulation of liquid embossing was developed by coupling fluid flow in a thin liquid film to the diffusion of solvent into a PDMS stamp. The model accurately predicts real aspects of the printing process including the time required to stamp and usable stamp geometries. OLE was designed to address some of the limitations of liquid embossing. In OLE the patterned liquid film is transferred to a different substrate, allowing finer control over geometry and material placement and leaving behind excess material trapped during stamping. All-printed electrostatic actuators were fabricated using OLE by patterning gold on flexible polyimide and then under-etching with oxygen plasma.<br>The polyimide acts as a sacrificial material, dielectric layer, and mechanical substrate. Square electrostatic actuators 50 microns on a side can modulate light up to approximately 1 kHz with fields of 1-2 volts per micron. These actuators also show a sharp non-linear response to driving voltage that could be used as part of a passive row-column addressing scheme.<br>by Eric Jamesson Wilhelm.<br>Ph.D.
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PAVESI, ANDREA. "Bioreactors and microbioreactors for electromechanical stimulation in cardiac tissue engineering." Doctoral thesis, Politecnico di Torino, 2012. http://hdl.handle.net/11583/2503040.
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This PhD thesis work was focused onto the development of advanced culture systems for laboratory studies of cardiac tissue engineering, featuring controlled electrical, or combined electro-mechanical stimulation of the culture environment. In consideration of the different research interests involved at the diverse hierarchical levels,the work was developed along two parallel lines acting at two different length scales,namely i) the development of macroscopic bioreactor devices suitable to carry out stimulated cell cultures with traditional cell-lab tools and procedures; ii) the development of engineering solutions for applying the electrical/electromechanical stimulation in microscale-oriented studies, namely in cell cultures performed in microfluidic, or lab-ona-chip, systems.
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Zhang, Xu. "Implicitly-coupled electromechanical and electromagnetic transient analysis." Thesis, Illinois Institute of Technology, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3664035.
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<p> The operation of an electrical power system involves continuous electromechanical and electromagnetic interaction of energy among the system components. Under normal operation, the system behavior could be represented by voltage and current phasors in the frequency domain. However, the system may not work on the fundamental frequency following some fast transients (loss of generator, switching event, system disturbance and etc.), at this time we need specific tools to investigate the dynamic scenario.</p><p> Transient stability (TS) simulator, also referred to as electromechanical transient simulator, running at time steps on the order of milliseconds and only capable of capturing the fundamental frequency transient, is used for the analysis of large-scale networks. On the other hand the electromagnetic transient (EMT) simulator running at time steps on the order of microseconds, with detailed equipment modeling is capable of analyzing transients over a wider frequency spectrum; however, it is computationally onerous, so it is typically restricted to the analysis of small networks.</p><p> An electromechanical-electromagnetic transient simulator is the combination of a TS simulator and an EMT simulator, inheriting the merits of both programs The basic idea of an electromechanical-electromagnetic simulator is to decompose the power system into two broad categories: a large connected TS network (main network) and smaller EMT network (detailed subsystem). The main network is running on TS simulator while the detailed subsystem is running on the EMT simulator. The implicitly-coupled electromechanical and electromagnetic simulator has TS and EMT simulators coupled at the equation solution level, which could ensure the consistence of the solution between TS and EMT simulation.</p><p> Instead of using fundamental frequency equivalent model of the main network in EMT simulation of implicitly-coupled electromechanical and electromagnetic simulator, a frequency dependent network equivalent (FDNE) model is utilized to preserve the non-fundamental frequency fast transient response of the main network.</p><p> Along with the implementation of FDNE model, this research work also propose a new TS simulator that is capable of running three-phase transient stability simulation under fundamental and non-fundamental frequency simultaneously. Furthermore the performance of implicitly-coupled electromechanical-electromagnetic transient simulator could be improved with the implementation of this new TS simulator.</p>
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Calbry-Muzyka, Adelaide S. "Technical development of an electromechanical braille labeler." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54527.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 36-37).<br>The work presented in this thesis concerns the development of an electromechanical device that prints labels in braille. For blind and visually impaired people, differentiating between similarly-shaped objects - CDs, medication bottles, food cans, etc. - is a challenge that can be solved by affixing braille labels to the surface of these items. However, the existing technology for making braille labels is either fully manual and slow, or too large to be portable. As a result of this identified need, the first prototype of a braille labeler was developed in the fall of 2008. However, several outstanding mechanical and design issues remained. During this thesis, the first prototype was tested with focus groups to identify these issues. These included the lack of a cutting mechanism for the tape, the uncomfortable shape and size of the device, and the ease of manufacturing of some components. A second prototype was designed and built, resolving these problems.<br>by Adelaide S. Calbry-Muzyka.<br>S.B.
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Spencer, Matthew Edmund. "Design Considerations for Nano-Electromechanical Relay Circuits." Thesis, University of California, Berkeley, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3733438.
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<p> Complementary metal oxide semiconductor (CMOS) technology has a minimum energy per operation, and that limitation is one of the myriad hurdles CMOS faces as it reaches small scales. This minimum energy is set by the balance between leakage energy and dynamic energy in subthreshold CMOS circuits, and sets floors on the achievable energy of digital units. A new, post-CMOS device with a sharper subthreshold slope than CMOS would be able to sidestep this minimum energy constraint. </p><p> A candidate device called a nano-electromechancial (NEM) relay has recently emerged. NEM relays are small, integrated, capacitively-actuated, mechanical switches. The devices have demonstrated extremely high subthreshold slopes: ten orders of magnitude over a millivolt of swing. However, in the same lithographic process they are twenty times larger than a minimum sized CMOS device, their gate capacitance is ten times that of a minimum sized CMOS device, and their mechanical motion is an order of magnitude slower than a CMOS inverter. Can NEM relays improve digital systems even with these drawbacks? </p><p> With proper circuit design, simulations say "yes". This dissertation examines three of the critical components of digital systems—logic, timing, and memory—and proposes NEM circuits which mitigate the weaknesses of the technology while achieving design goals. Simulations show that optimized relay logic, which arranges for all of the slow movement of relays to happen at the same time, can achieve an improvement of 10x in energy-per-operation below the CMOS minimum energy point at a penalty of 10x in delay and 3x in area. This logic style is experimentally demonstrated. In addition, relay latch based timing with staticization in the feedback path is simulated, which results in a working relay pipeline with zero mechanical delays of timing overhead. Finally, a new device called NEMory is proposed to build dense, non-volatile, mechanical memory. A hybrid NEMory/CMOS array is simulated, and its performance is compared to other memory solutions. The NEMory density is higher than any non-volatile memory except for multi-level cell, o-chip Flash, and its read and write energy are lower than any other non-volatile technology. Finally, the scaling and process limits of realizing mechanical devices are discussed in the context of future work.</p>
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Bryant, Reginald (Reginald Eugene) 1978. "High-index-contrast electromechanical optical switches." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65998.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, June 2011.<br>"June 2011." Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 278-288).<br>System developers are looking to replace protocol-dependent, bandwidth-limited optical networks with intelligent optically-transparent integrated photonic networks. Several electromechanical optical switches are explored with the intent of being utilized as optical switching elements in transparent, integrated photonic networks. The electromechanical optical switches are based on high-index-contrast waveguide optics that is integrated with electrostatic parallel plate actuators on submicron scales. High-index-contrast waveguides are attractive due to their reduced bending radius and low in-plane scattering and optical loss. These qualities of high-index-contrast waveguides make them uniquely suited for low-cost, large-scale integration. The parallel plate actuators are used to control the waveguide light switching by mechanically establishing and terminating light pathways on time scales well below 100s of microseconds. Investigations of light pathway coupling schemes and parallel plate actuator configurations led to the development of several device structures that are categorized in three distinct device generations. Design premiums were placed upon device footprint minimization, polarization independence, high extinction ratios, and operational robustness.<br>by Reginald Eugene Bryant.<br>Ph.D.
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Wang, Jin. "Computational study of electromechanical instabilities in dielectric elastomers." Thesis, Boston University, 2014. https://hdl.handle.net/2144/21271.
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Thesis (M.Sc.Eng.)<br>Dielectric elastomers (DEs) have attracted significant attention in recent years and have been found to provide excellent overall performance in actuation-based application. This thesis will introduce the fundamentals of DEs, derive the field and finite element equations for simulating its deformation, and then focus on numerically studying electromechanical instabilities, in particular electrostatically driven creep and the effect of pre-stretch on surface (creasing) instabilities. First, a nonlinear, dynamic finite element model coupled with a finite deformation viscoelastic constitutive law is utilized to study the inhomogeneous deformation and instabilities resulting from the application of a constant voltage to dielectric elastomers. Theoretical studies are performed of two problems that have been experimentally observed, i.e. electromechanical snap-through instability and bursting drops in a dielectric elastomer. In general, increasing the viscoelastic relaxation time leads to an increase in time needed to nucleate the electromechanical instability. However, it is found that the time needed to nucleate the instability of these two cases scales with the relaxation time. Second, the effect of pre-stretch on the performance of dielectric elastomers is studied. Two cases are studied, the electromechanical snap-through instability under equibiaxial pre-stress, and a strip under uniaxial pre-stretch. It is found that prestress markedly increases the stability of the elastomers, while pre-stretch increases the critical field for electro-creasing instability.<br>2031-01-01
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Ahmed, Shaheen Sooleman. "Damping of electromechanical oscillations using power system stabilizers." Doctoral thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/9644.
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Includes bibliographical references.<br>This thesis deals with the damping of electromechanical oscillations using Power System Stabilizers (PSS). The thesis focuses on three problems associated with the damping of these oscillations, namely the determination of the optimal locations of the PSS, the determination of the best control structure of the PSS and the design of robust PSS. We develop two new methods for determining the optimal locations of the PSS. These two methods are based on Total Modified Coupling Factors (TMC) and optimization by Simulated Annealing (SA). The TMC is a measure of the damping influence of each machine pair on several power system modes. The TMC incorporates the effect of the performance and the type of excitation system of the generator. The method based on TMC is tested on a nine-bus benchmark network. In the method based on SA, we formulate the PSS placement problem as a discrete nonlinear optimization problem. The objective function corresponds to the damping of the electromechanical modes of the system. In this method, the placement is performed simultaneously for all PSS. Using SA, we obtain a placement scheme which guarantees that the undesired poles can be controlled with finite control energy. As a result of the optimization formulation, the method based on SA is computationally more intensive than the method based on TMC. We demonstrate the method based on SA on two networks namely, a seven-bus network and a 35-bus equivalent of the Eskom network. The problem of determining the control structure for damping of the electromechanical oscillations is composed of three aspects namely, the type of feedback, the type of signal and the type of control.
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Chaney, Rachel M. "Electrical interfaces for electromechanical and energy systems." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61147.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 59).<br>The design, construction, and testing of a versatile robot driver circuit is described. The printed circuit board produced can be used as an interface between any two-motor robot and the R31-JP, an eight-bit microcontroller system. The circuit board implements sensing, Ethernet communications, and motor driving modules. These modules are composed of eight bit peripheral microcontroller chips such as the ADC0808 analog-to-digital converter and the 84C54 programmable timer. Additionally, a programmable logic chip, the GAL22V1O creates the signals necessary for driving both direct current and stepper motors. The robot driver printed circuit board was testing in simulation and in hardware. The results are listed in this document. This robot driver will allow for the use of wireless mobile robots that can be used in future iterations of the Microcomputer Project Laboratory, 6.115. The design, construction, and testing of a sensor signal conditioning printed circuit board for use in a hardware emulator for a Gas Turbine Generator used on the US Navy's DDG-51 Class Destroyer is described. The system emulator project seeks to construct a scaled hardware model and perform control experiments to explore different shipboard power distribution systems. The synchronization of two generators is necessary to fulfill these goals to extend versatility and allow for the testing of new power distribution systems. The signal conditioning circuit uses digital logic to develop a frequency sensor, which reduces the required sampling rate. Additionally, analog amplifier circuits are used to condition the signals output by voltage and current transducers, preparing them for analog to digital conversion. These signals will be used to implement the synchronization and load-balancing algorithms described in this document. This scaled model for shipboard power distribution systems will be demonstrate and compare experimental power distribution systems that will lead to increases in the safety and efficiency of shipboard power distribution systems.<br>by Rachel M. Chaney.<br>M.Eng.
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Jackson, Deron K. (Deron Keith). "Inductively-coupled power transfer for electromechanical systems." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9956.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.<br>Includes bibliographical references (p. 359-366).<br>by Deron Keith Jackson.<br>Ph.D.
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Leong, Hoi San. "Effect of corrosion inhibitor and laser surface treatment on corrosion behavior of steel used in chilling system." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2550589.
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Sio, Sei Hoi. "Concurrent engineering in modern mold design and production." Thesis, University of Macau, 2001. http://umaclib3.umac.mo/record=b1446138.
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Said, Fahad. "Energy analysis and traffic surveillance using micro-electromechanical sensor." Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1597790.
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<p>The advancement of technology has led to significant improvement in the field of Wireless Sensor Networking (WSN). Great success in Micro-Electro-Mechanical System (MEMS) sensor with respect to their size, energy consumption and cost, as well as miniaturization of radio frequency (RF) transceiver and energy/cost efficient micro-controllers has led to the development of small and very low power wireless sensor nodes that would replace the traditional wired system.
The sensor nodes can communicate with other nodes in an intelligent sensor network and can last longer due to their low power consumption. Motivated by the advancement in this field, a wireless MEMS sensor based system is proposed for traffic surveillance to collect the traffic data.
Furthermore, a detailed energy analysis is conducted on the system and the algorithm is improved to minimize the overall power consumption. With refined software code and utilizing low power hardware components, the surveillance system can remain functional for years.
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Liu, Wenjiao. "Electromechanical response of carbon nanotube/carbon fibre epoxy composites." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123267.
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Carbon fibre (CF) reinforced polymers have become the most widely used composites in theaerospace industry. However, ensuring the integrity of composite structures remains one of themain challenges. By measuring the change in electrical resistance of these materials, it is feasibleto monitor strains and damage initiation and accumulation in-situ and in real-time. The objectiveof this work is to investigate the potential of adding carbon nanotubes (CNTs) to existing CFpolymersto improve strain self-sensing. First, the DC and AC conductivities of epoxy containingdifferent CNT weight concentrations are measured in order to characterize the percolationthreshold. Second, the variation in electrical resistance as a function of electrode distance isinvestigated for CF-epoxy and CF-CNT-epoxy composites. The results show that the addition ofCNTs increases through-thickness conductivity by primarily reducing CF-CF contact resistancerather than increasing the number of CF-CF contacts. In addition, the presence of CNTsengenders a more homogeneous CF-CF contact resistance distribution. Third, theelectromechanical behaviours of CF-epoxy and CF-CNT-epoxy composites are compared viatension, compression, and flexure experiments while simultaneously monitoring electricresponses. The addition of CNTs results in: 1) improved sensitivity under compression due to thecreation of more CF-CF contacts; 2) better linearity under tension due to a more gradual changein CF-CF contact resistance; 3) better electric response reproducibility and repeatability due tomore homogeneous distribution of CF-CF contact resistance. Finally, an existing analyticalmodel is modified to estimate the change in surface resistance on both the tension andcompression sides of flexural specimens using the results of tension- and compression-only testsas inputs. The modelling data is then compared with the measured change in surface resistanceunder flexural load and shows good agreement. The model advances CF-CF contact as thedominating mechanism in the change of surface resistance under mechanical loading—especiallyin compression.<br>Les polymères à fibre de carbone (FC) sont de nos jours les composites les plus largementutilisés dans le domaine aéronautique. Cependant, assurer l'intégrité de ces structures compositesreste l'un des principaux défis. En mesurant la variation de la résistance électrique descomposites polymère-FC, il est possible de surveiller les déformations et les dommages in-situen temps réel. L'objectif de ce travail est d'étudier l'influence de l'addition de nanotubes decarbone (NTCs) dans des polymère-FC sur la capacité d'auto-détection des déformations et desendommagements structurels. Premièrement, les conductivités continues et alternatives derésines époxy contenant différentes concentrations en poids de NTC sont mesurées afin decaractériser le seuil de percolation. Deuxièmement, la variation de la résistance électrique enfonction de la distance de l'électrode est étudiée pour les composites époxy-FC et époxy-CFNTC. Les résultats démontrent que l'ajout de NTC augmente la conductivité à travers l'épaisseur,en réduisant principalement la résistance de contact FC-FC plutôt que d'augmenter le nombre decontacts FC-FC. De plus, l'ajout de NTC permet une répartition plus homogène de la résistancedes contacts FC-FC. Troisièmement, les comportements électromécaniques peuvent êtrecomparés en mesurant les réponses électriques d'échantillons en temps réel soumis à des tests detraction, compression, et flexion. L'ajout de NTC conduit à: 1) une amélioration de la sensibilitésous contraintes de compression due à davantage de contacts FC-FC créés, 2) une meilleurelinéarité de la résistance électrique sous contraintes de traction due à un changement plusprogressif de la résistance de contact FC-FC, 3) une meilleure reproductibilité et répétabilité desréponses électriques grâce à une répartition plus homogène de la résistance de contact FC-FC.Enfin, un modèle analytique est modifié pour estimer la variation de la résistance de surface enflexion en utilisant les résultats des essais de traction et de compression comme donnéesd'entrée. Les données obtenues par le modèle sont ensuite comparées avec la variation de larésistance de surface mesurée lors des essais en flexion, et présentent une bonne corrélation. Cemodèle démontre en plus que la variation des contacts FC-FC domine la variation de résistancede surface sous chargement mécanique, en particulier la compression.
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Takahashi, Satoshi Ph D. Massachusetts Institute of Technology. "Integrated optical switching using titanium nitride micro electromechanical systems." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35645.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.<br>Includes bibliographical references (p. [116]-[127]).<br>This thesis reports an integrated optical wavelength specific switching device for applications in optical integrated circuits (OICs) based on micro electromechanical systems (MEMS). The device consists of a ring resonator add-drop filter and a conductive MEMS bridge which is actuated by electrostatic force. Introducing conductive material into the electromagnetic evanescent field of the ring waveguide results in loss in the propagating light within, disabling the resonance and the filtering capabilities of the ring resonator. Therefore, by actuating the MEMS bridge in and out of the waveguide's evanescent field, the filter can be toggled between the on and off states. One large problem that must be faced when fabricating and actuating a MEMS cantilever or bridge structure for this type of device is the residual stress that may deflect the structure in an undesired way. This is because the vertical displacement of the structure is crucial. In order to solve this problem, this thesis is based on the use of titanium nitride (TiN) as structural material for the bridge. Titanium nitride has very attractive mechanical properties as well as good conductivity, which makes it an ideal structural material for electrostatically actuated devices.<br>(cont.) Moreover, the residual stress within the material can be relieved by proper control of deposition conditions and/or post processing. This thesis focuses on the post process annealing of titanium nitride in order to eliminate the residual stress in the structure and obtain a fiat bridge profile. Titanium nitride MEMS bridge structures were fabricated and tested. Their deflection from a flat state and stress was measured and characterized, and a structure with minimal residual stress was successfully fabricated. The actuation of the MEMS bridge is also demonstrated, and its characteristics are analyzed. Also discussed is the possibility of extending the design of the MEMS switch to implement the three-electrode ultra-fast strain-induced switching and MEMS wavelength tuning of an integrated optical filter. A realistic design of these devices is proposed in context with the requirements imposed by the optical telecommunication industry, and fabrication methods are considered. Simulations have been conducted using finite element analysis and mode solving to establish the feasibility of these designs.<br>y Satoshi Takahashi.<br>S.M.
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Johnson, David. "Design considerations and implementation of an electromechanical battery system." Doctoral thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/5200.
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Includes bibliographical references.<br>This thesis covers the design and implementation of a low cost electromechanical battery using an outside rotor permanent magent Halbach array with hybrid magnetic bearings and heat pipe cooling. The theoretical calculations include finite element analysis. A dipole Halback array produces a uniform flux distribution inside the cylindrical statoe, where straight windings on an iron-less stator are placed near the inner boundary.
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Foley, Joseph Timothy 1976. "An infrastructure for electromechanical appliances on the Internet." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/37193.
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Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.<br>Includes bibliographical references (p. 73-74).<br>In this thesis, I designed and constructed an intelligent microwave capable of automatically determining the time required to properly cook commercially-packaged foods. This research involved creating a database infrastructure capable of supporting a huge amount of data distributed throughout the internet. It was accomplished through a number of techniques involving careful application of the existing internet technologies: the Domain Naming System and the World Wide Web. A prototype using Radio Frequency ID tags was built and tested with several test foods.<br>by Joseph Timothy Foley.<br>S.B.and M.Eng.
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Kren, David Edward. "High carbon-doped base HBTs : growth and processing engineering." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274478.
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Cheong, Chan Wa. "Development of heat transfer correlation and flow regime map for heated horizontal pipe using support vector machines." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2493970.
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Wen, Quan. "An experimental investigation of inner surface roughness on friction factor for horizontal micro-tubes." Thesis, University of Macau, 2010. http://umaclib3.umac.mo/record=b2493677.
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Rutledge, Matthew S. "Aircraft Gearbox Dynamics Subject to Electromechanical Actuator Regenerative Energy Flow." Wright State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=wright1292358176.
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Martineau, Brenda L. "Learning technologies used by CVTC electromechanical graduates in manufacturing." Online version, 2002. http://www.uwstout.edu/lib/thesis/2002/2002martineaub.pdf.
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Ceru, Maricel. "Acceleration feedback in model predictive control of electromechanical drive systems." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/9372.
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This thesis discusses the use of acceleration measurements in predictive control schemes for electromechanical positioning systems. The proposed method is intended to improve the tracking error while maintaining the controllability and the robustness of the' controllers. The influence of acceleration feedback on controllers and observers of predictive type is evaluated, and the results are compared with those obtained by classical control schemes, without this type of feedback. Multiple approaches are subsequently compared, from the classical PID, Linear Quadratic Gaussian (LQG) control, to Dynamic Matrix Control (DMC) with state feedback and DMC with acceleration feedback (DMC/AF) as well. The simulations and the experiments are done using the framework of MATLAB/Simulink and dSPACE computer packages, on an electromechanical positioning system (EMPS) with friction wheel used at the Cologne Laboratory of Mechatronics (CLM). A controller design suite using GUI developed to facilitate industrial implementation has been used for rapid testing of diverse schemes. The observers for non-measured states were of Kalman filters type. (Abstract shortened by UMI.)
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Marmorato, Leonardo F. (Leonardo Francesco) 1982. "Scaled electromechanical modeling of the F-35A Joint Strike Fighter." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32769.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.<br>"June 2004."<br>Includes bibliographical references.<br>During the early 1990s, The U.S. Department of Defense embarked on a search for an affordable, next generation fighter aircraft that could fit the common needs of the Navy, Air Force, and Marines, as well as several allied nations. Lockheed Martin Corporation provided the answer with a cutting-edge fighter jet design that fulfilled all of the DoD's needs; the F-35 Joint Strike Fighter. The JSF was produced in three different variants, the first and simplest being the F-35A CTOL (Conventional Take-off, Landing), designed especially for the Air Force. In order to explore the underlying principles of the JSF's design as well as its aerodynamic characteristics, a scaled electromechanical model of the JSF F-35A variant was constructed using limited information about the aircraft's unclassified dimensions and features. The design process involved at first a CAD solid model of the entire structure. Once the computer-based model was completed, parts were manufactured with high precision out of 1/16" polycarbonate with the aid of a waterjet. The scaled model also had several electrical components such as an R/C transmitter and receiver, servos for controlling the aerodynamic surfaces; high speed ducted fan motor for providing the necessary thrust, and LEDs to mimic the aircraft's external lighting system. Despite some minor differences in detail, the F-35A 25:1 scaled model closely resembled most of the physical features contained in the Joint Strike Fighter conventional takeoff/landing variant. It should be made clear that the decision for making the airframe out of polycarbonate was greatly influenced by time limitations and budget constraints experienced throughout the term. Our original intention was to make the airframe completely out of balsa wood,<br>(cont.) a material with a stiffness (E) similar to that of polycarbonate, yet up to eight times lighter. Nevertheless, the fact that balsa stock comes in relatively small sizes meant more time would be spent loading and unloading pieces on the waterjet. In general, having limited resources had a lot of leverage on our design approach, especially so when the cost for operating the waterjet at the LMP facilities was tagged at $100 per hour. It is then proposed as a side project to build the same model out of balsa for flying purposes in the near future.<br>by Leonardo F. Marmorato.<br>S.B.
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Wong, Christine Y. 1975. "Strategic outsourcing of micro-electromechanical systems (MEMS)." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/43726.
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Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; in conjunction with the Leaders for Manufacturing Program at MIT, 2002.<br>"June 2002."<br>Includes bibliographical references (leaves 60-61).<br>ABB Automation is starting to experiment with Micro-electrical Mechanical Systems (MEMS) as an enabling technology for their products. If ABB's implementation of MEMS is found successful, it will be able to create breakthrough products and services that will revolutionize the market in ABB's industrial sensors, instrumentation and analytical areas. The thesis begins with a description of ABB as a company and then provides a brief overview on MEMS and the challenges ABB faces as it tries to commercialize MEMS enabled products. A literature review is also included to explain how companies can better profit from technological innovations such as MEMS. An analysis of ABB's decision to outsource MEMS is described with multiple frameworks including a vertical integration versus outsourcing model as well as a traditional make or buy decision assessment from a financial perspective. The decision to outsource is valid given the stage of the technological life cycle and the company's resolution to use MEMS in selected products. Since the strategic fit argument is still questionable through much of ABB, outsourcing is a legitimate choice for MEMS. Outsourcing allows a greater amount of flexibility and the least amount of capital investment. Although ABB has decided to outsource its MEMS capabilities, it has to realize that there is a possibility of vertical market failure with MEMS. There are very few suppliers in the market today with potentially fewer in the future as mergers and acquisitions begin to take place once a dominant design is established. This vertical market failure encourages vertical integration and not outsourcing.<br>Christine Y. Wong.<br>S.M.<br>M.B.A.
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Chang, Woo Sok 1964. "An electromechanical valve drive incorporating a nonlinear mechanical transformer." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/38201.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.<br>Includes bibliographical references (leaves 145-147).<br>In traditional internal combustion engines, a camshaft acts on the valve stems to open and close the valves. Valve timing is fixed relative to piston position. On the other hand, if a valve is flexibly controlled by a variable valve actuation (VVA) system, we can achieve significant improvements in fuel efficiency, engine performance, and emissions. One of the most advanced variable valve actuation systems is the VVA operated by an electromechanical actuator without a camshaft, the so-called bi-positional electromechanical valve drive (EMVD). Existing EMVDs characteristically use a spring to provide the required mechanical power for operating a valve. The use of a spring provides many benefits to the design of the system, but it also results in difficult design challenges. The large holding force against the spring at the ends of the stroke suggests the use of a normal-force electromagnetic actuator, which, from a servomechanical point of view, is considerably inferior to a shear-force actuator. Furthermore, the large holding force generates a large jerk at the beginning and the end of a stroke and makes it difficult to achieve soft valve landing. An innovative electromechanical valve drive (EMVD) design is proposed, which incorporates a nonlinear mechanical transformer and a shear-force actuator. This allows not only fast but also smooth valve motion, almost zero seating velocity, zero holding power, and improved control with acceptable electric power. This proposed concept is modeled, analyzed, simulated, designed, and implemented. Experimental results show the beneficial features of the promising proposed concept.<br>by Woo Sok Chang.<br>Ph.D.
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Alvarez, María José (Alvarez Varea) 1971. "Analysis of the accessory business : focus on electromechanical grips." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/46262.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, 1999.<br>Includes bibliographical references (p. 87).<br>Today, many manufacturing companies are facing numerous challenges that had not been present in the past. The paradigm of how companies must perform has dramatically changed over the years. Back in the 1980's customer service was used as a tool to gain competitive advantage. Now, good customer service is expected from the vendor and few companies survive if they don't embrace best of breed practices such as this one. In addition, quality, cost and delivery time have become intrinsic values for the consumer. Not only does the product need to be at a lower cost but they also need to be of higher quality and be delivered promptly. Instron Corporation is one of the companies that is searching for ways to remain as the industry leader given the fierce competition they face. This company sells electromechanical testing machines and has a large after market for accessories for these machines. While the company has placed a lot of effort into certain areas, others have been completely neglected. This project will focus on the accessory business of the electromechanical systems. The intent has been to identify the major problems that the accessory business faces and provide the company with a set of tools and guidelines that will help the company perform more effectively. Due to time constraints, the research was done on one segment of the accessory business, the grips. Therefore, this thesis should be used as a template for the rest of the accessory business. Topics included are; product rationalization, redesign with product platforms, and an inventory model to reduce existing inventory investments and increase inventory turns.<br>by María José Alvarez.<br>S.M.
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Leong, Iok Sam. "An investigation of the usage of small scale furnace for fire resistance test." Thesis, University of Macau, 2006. http://umaclib3.umac.mo/record=b1446610.
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Nabki, Frederic. "Silicon carbide micro-electromechanical resonators for highly integrated frequency synthesizers." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=94958.
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A low temperature (<300ºC), low-stress micro-electromechanical systems (MEMS) fabrication process based on a mechanically superior silicon carbide structural layer is outlined. The process is designed for low-cost film deposition and CMOS post-integration, stemming from chemical and thermal compatibility. MEMS beam resonators and arrays are fabricated, and have higher power handling capabilities and operating frequencies, compared to those of similar polysilicon-based resonators. A tuning method based on integrated heaters is introduced, yielding constant insertion loss tuning and wide tuning ranges. Quality factors of up to 1493 and resonant frequencies of up to 26.2 MHz are measured. A MEMS beam resonator model that accounts for electrostatic and mechanical non-linearities, and that may be used in circuit simulators is proposed. The model captures non-linear effects such as resonant frequency shifting and Duffing behaviour. It offers valuable insights into the trade-offs involved in the design optimization of MEMS resonator-based oscillators. Such oscillators are designed using an integrated high gain-bandwidth trans-impedance amplifier (TIA) combined with a resonator. The TIA employs automatic gain control to mitigate the inherent low power handling capabilities and the non-linearities of the MEMS device, thus minimizing their effect on phase noise. A highly integrated 1.7-2.0 GHz digitally programmable fractional-N frequency synthesizer using a MEMS resonator-based oscillator as its frequency reference is presented. Due to the dimensions of the MEMS device (e.g. 25 um by 114 um), the entire system with a total area of 6.25 mm2 can be housed in a small standard chip package. This considerably reduces the form factor and cost of the system, compared to using an external crystal as a reference. The synthesizer has a fine frequency resolution (~11 Hz) in order to allow for high output frequency stability when used with an appropriate control loop. A fully integ<br>Une technologie de fabrication de microsystèmes électromécaniques (MEMS) à basse température (<300ºC) incorporant une couche structurelle de carbure de silicium à faible contrainte est décrite. Une implémentation peu dispendieuse et une intégration avec les procédés CMOS qui découle d'une compatibilité chimique et thermique sont possibles. Des micro-résonateurs en forme de poutre et des résonateurs couplés sont fabriqués. Ceux-ci transigent des puissances plus grandes et ont des fréquences de résonance plus élevées comparativement à des structures en poly-silicium. Une méthode pour ajuster la fréquence de résonance avec un élément chauffant intégré est introduite et permet une perte d'insertion constante et une vaste gamme d'ajustement. Des facteurs de qualité allant jusqu'à 1493 et des fréquences de résonance allant jusqu'à 26.2 MHz sont mesurés. Un modèle est conçu pour tenir compte des non-linéarités électrostatiques et mécaniques du résonateur et peut être utilisé au sein d'un simulateur de circuits. Il capture les effets non-linéaires tels l'ajustement de la fréquence de résonance et le comportement de Duffing. Les compromis lors de la conception d'oscillateurs basés sur des résonateurs peuvent être discernés avec ce modèle. Ces oscillateurs sont conçus à l'aide d'un amplificateur de transimpédance qui emploie un contrôle du gain automatique pour réduire l'impact des non-linéarités du résonateur et permet la réduction du bruit de phase. Un synthétiseur de fréquences à division fractionnelle hautement intégré est présenté. Celui-ci couvre la bande de 1.7 GHz à 2.0 GHz et incorpore un oscillateur basé sur un résonateur MEMS pour sa référence de fréquence. Les petites dimensions du résonateur (ex: 25 um par 114 um) confèrent au système une superficie totale de 6.25 mm2 et permettent de le placer dans un boitier. La superficie et le coût du système sont réduits comparativement à un
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Zhang, Zai Yong. "Simultaneous fault diagnosis of automotive engine ignition systems using pairwise coupled relevance vector machine, extracted pattern features and decision threshold optimization." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2493967.
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Råberg, Ingela. "Efficiency verification of an electromechanical linear actuator." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-303147.
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Cascade Drives has developed an electromechanical linear actuator with a patented feature which allows for load sharing between multiple pinions interacting on the same rack. This arrangement has proven resilient for shock loads, and allows for compact gearbox designs with very high load rating. For the further development of the actuators, access to proper simulation models for various gearbox behaviours is important. One such behaviour is that of the gearbox efficiency. In 2020, a Simulink model for predicting the gearbox efficiency was produced. The aim of this thesis has been to verify the 2020-model using Romax, and also to continue the development of the Simulink model so that it can also handle gearbox acceleration and backdrive. The results from the Romax modelling were while not identical to the 2020 Simulink model results, close enough that the Simulink model could be considered verified through that method. The results from the new dynamic Simulink model were in the same order of magnitude as those of the other two models. To achieve an absolute accuracy for the models, efficiency testing on physical actuators should be executed.<br>Cascade Drives utvecklar en ny typ av elektromekaniska linjära ställdon. Ställdonen är elektromekaniska och följer konceptet med en kuggstång och pinjonger som drivs av en elektrisk motor. I själva växellådan finns patenterad teknik som tillåter att lasten från kuggstången fördelas jämnt mellan flera pinjonger utan att systemet överbestäms. Detta möjliggör kompakta växellådor till ställdonen som kan ta höga laster och dessutom fungerar utmärkt för chocklaster. I och med att det är helt ny teknik erfordras beräkningsmodeller så att växellådans beteende kan förutspås redan innan prototyper tillverkas. En beräkningsmodell för ställdonets statiska verkningsgrad utvecklades 2020 i Simulink. Detta arbete syftar till att genom Romax verifiera funktionaliteten av modellen från 2020. Dessutom utvecklades modellen vidare för att hantera de dynamiska lastfallen när ställdonet accelererar och drivs från last. Modelleringen Resultaten från modelleringen i Romax och de från den statiska Simulinkmodellen från 2020 var snarlika med en skillnad på ungefär ± 1 %. Graferna över växellådans verkningsgradsbeteende över varierande last och hastighet skiljde sig tillräckligt lite för att bedömningen skulle vara att den statiska modellen kan betraktas som verifierad av Romax. Även den nya dynamiska Simulinkmodellen genererade resultat som liknade de från de statiska Simulinkoch Romax modellerna. För att få en absolut precision på samtliga beräkningsmodeller rekommenderas att genomföra verkningsgradstester på fysiska prototyper för framtiden.
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Zhong, Jian Hua. "Intelligent system based facility monitoring and fault diagnosis of power generators." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2550655.
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Jarmul, Edward S. "Investigation of interface parameters that influence the electromechanical transfer of tactile information /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487678444259659.
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Seth, Danny 1978. "A remotely automated microscope for characterizing micro electromechanical systems (MEMS)." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86762.
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Dutta, Sumit Ph D. Massachusetts Institute of Technology. "Floating-point unit (FPU) designs with nano-electromechanical (NEM) relays." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/84724.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Includes bibliographical references (pages 71-74).<br>Nano-electromechanical (NEM) relays are an alternative to CMOS transistors as the fabric of digital circuits. Circuits with NEM relays offer energy-efficiency benefits over CMOS since they have zero leakage power and are strategically designed to maintain throughput that is competitive with CMOS despite their slow actuation times. The floating-point unit (FPU) is the most complex arithmetic unit in a computational system. This thesis investigates if the energy-efficiency promise of NEM relays demonstrated before on smaller circuit blocks holds for complex computational structures such as the FPU. The energy, performance, and area trade-offs of FPU designs with NEM relays are examined and compared with that of state-of-the-art CMOS designs in an equivalent scaled process. Circuits that are critical path bottlenecks, including primarily the leading zero detector (LZD) and leading zero anticipator (LZA) blocks, are carefully identified and optimized for low latency and device count. We manage to drop the NEM relay FPU latency from 71 mechanical delays in a CMOS-style implementation to 16 mechanical delays in a NEM relay pass-logic style implementation. The FPU designed with NEM relays features 15x lower energy per operation compared to CMOS.<br>by Sumit Dutta.<br>S.M.
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Parulkar, Wrutu Deepak. "Electromechanical Characterization of Poly(Dimethyl Siloxane) Based Electroactive Polymers." VCU Scholars Compass, 2005. http://scholarscompass.vcu.edu/etd/1446.
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The main objectives of this thesis are 1) to evaluate the effect of cross-linking polar cyano phenyl (CN) groups on poly (dimethyl siloxane) (PDMS) and 2) to characterize the electromechanical properties of the resulting CN-PDMS blend as an electroactive actuator. Materials responding to an external stimulus are referred to as electroactive materials. There are several phenomena, which govern the mechanism in these materials, such as piezoelectricity, Maxwell's effect, ferroelectricity, electrostriction to name a few. These electroactive materials can be employed in several applications such as biomedical devices, robots, MEMs, aerospace vehicles, where the application is governed by the specific mechanism. However in order for the materials to be used effectively, they need to be thoroughly characterized to understand their behavior under factors like electric field, temperature, frequency and time.The present work focuses on developing an electroactive actuator, which has tailorable properties, allowing a wide operational temperature window from -100°C to 200°C and stability in harsh conditions. The characterization of the CN-PDMS polymer blend is done in two folds. First the physical properties of the polymer system are characterized by performing tests such as Dielectric Spectroscopy, Differential Scanning Calorimetery and Thermally Stimulated Current measurement. These techniques offer complete understanding of the structure-property relationship and effects of the functional groups on the dielectric and relaxation behavior of the polymer. The Dielectric Spectroscopy and the Thermally Stimulated Current analysis are used to elucidate the primary and the secondary relaxations, such as molecular mobility, interfacial polarization and dipolar relaxation. Dielectric Spectroscopy reveals that the molecular weight of PDMS does not affect the dielectric permittivity of the polymer blend. Also, Dielectric Spectroscopy clarifies the role of the CN polar group in the polarization of the CN-PDMS blend, inducing electromechanical strain in the polymer blend through electrostriction.The Differential Scanning Calorimetery is used to quantify the thermal behavior of the CN-PDMS polymer blend by quantifying properties such as melting temperature (Tm) and re-crystallization temperature of the PDMS polymer cross-linked with CN functional group. Results reveal that the thermal characteristics of the blend are not affected when PDMS is cross-linked with the functional CN moieties, meaning CN-PDMS maintains the advantages of PDMS in terms of stability towards harsh conditions, wide operating temperature and resistance to ultraviolet radiations.Following the physical characterization, electromechanical characterization of the CN-PDMS polymer blend is done to assess the electromechanical strain induced in the blend in response to electric field. The electromechanical strain is studied in two configurations; the electromechanical strain induced along the length of the polymer blend and induced through the thickness of the blend. These strain measurements are performed by applying both direct current as well as alternating current electric fields, and the induced electromechanical strain is studied as a function of amplitude and frequency of the electric field as well as the time of application of the electric field. The mechanism behind the development of the electromechanical strain and the nature of the strain under electric field is elucidated. The performance of the electroactive polymer is compared with several other polymeric actuators such as PVDF and PVDF-TrFE, polyurethane based actuators and ionomers. Comparison gives favorable results in terms of strains. In addition, CN-PDMS polymer system has the advantage of allowing control of processing of the blend, which is not present in all the other commercial electroactive polymers. The maximum electromechanical strain yielded along the length of the CN-PDMS polymer blend is 1.74 % when an electric field of 0.2MV/m is applied along the length of the polymer. Through the thickness, the maximum induced strain is 0.12 % for an electric field of 0.8 MV/m. Based on the nature of the strain yielded it is observed that the strain induced in the CN-PDMS blend is consistently proportional to the square of the electric field (E2). Moreover, the strain is driven by the concentration of the dipolar moieties (CN) present in the polymer blend.All the above-mentioned techniques used for thermal and electromechanical characterization of the CN-PDMS polymer blend illustrate the electrostrictive nature of the polymer under the study.
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Wang, Heng Yu. "Multimodal signal based fault diagnosis system for non-stationary electromechanical equipment." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3950614.
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Wroble, Daniel G. "Force Fight Study in a Dual Electromechanical Actuator Configuration." University of Dayton / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1512641850024148.
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Chong, Ian Ian. "Vibration control and genetic algorithm based design optimization on self-sensing active constrained layer damped rotating plates." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2493698.
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Wong, Ian Kai. "Numerical study of stokes' second flow problem." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2550664.
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Caulfield, F. Donald. "Electromechanical Actuator Development for Integrated Chatter Prediction on High Speed Machining Centers." NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-04222002-234733/.
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Machine tool chatter imposes limitations on the productivity and quality of modern high speed machining (HSM) operations. It has been shown that chatter prediction and avoidance strategies can lead to increased machining productivity if certain modal characteristics of the machine are known. The objectives of this research are to design and demonstrate an electromechanical actuator (EMA) to easily and accurately identify these characteristics. Design specifications for this actuator reflect a wide range of machine tools and operating conditions. A simulation-based design strategy is employed, based on traditional electromechanical analysis, finite element analysis (FEA), and computer simulations to ensure performance meets the design specifications. A prototype EMA system is built to validate the analytical results and demonstrate its capabilities as part of an automated chatter prediction and avoidance system. The EMA is shown to generate the required modal characteristics, namely frequency response functions (FRFs) and stability lobe diagrams (SLDs) quickly, accurately, and with fewer technical skill requirements than other vibration testing methods. Experimental machining tests demonstrate that the EMA can be an effective component of an integrated chatter prediction and avoidance system.
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Raboin, Peter J. "The mechanical behavior of maraging steel under extreme electromechanical and thermal conditions." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/37167.
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Tatem, Rachel E. "Portable electromechanical braille label maker : from a 2.009 prototype to a product." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/85781.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2009.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 27-28).<br>Most student projects never make the transition from a class prototype to a commercial product. This document is meant to be used as a guide by any student trying to turn an alpha prototype into a product on the market. The process is involved and there can be many challenges. There are also many approaches that might be adopted depending on the product and the goals of the inventor. This thesis begins with a discussion of technology transfer programs at three different universities and then looks into successful stories of student products. The focus then shifts to my own student product: a portable electromechanical Braille label maker that was developed in the MIT class 2.009, product engineering processes. The discussion focuses on the steps that have been taken thus far towards making the alpha prototype into a commercially available device, and discusses the steps that must be taken in the future.<br>by Rachel E. Tatem.<br>S.B.
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Coad, Margaret Mary. "A case study in troubleshooting electromechanical software-controlled systems : the InMotion² Robot." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98919.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (page 64).<br>The InMotion² robot is a clinical version of the MIT-Manus robot, which was developed in the 1990s to help with upper limb rehabilitation of stroke survivors. In 2015, experiments were planned to use the InMotion² robot for studies of human force and motion control. During preparation for the experiments, however, a malfunction was discovered in the robot. A series of systematic tests were carried out to determine what part of the robot was causing the malfunction. It was determined that the magnets on one of the two motors were slipping on the rotor shaft. This slippage caused the malfunctioning motor's torque output to range from 10% to 13% of the other motor's output given the same input signal. The malfunctioning motor was repaired, and the robot was reassembled. Tests were carried out to verify the performance of the robot, and the torque output of the malfunctioning motor was measured to range from 120% to 130% of the other motor's torque output, showing that the malfunction had been fixed.<br>by Margaret Mary Coad.<br>S.B.
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Gilbertson, Matthew Wright. "Electromechanical systems to enhance the usability and diagnostic capabilities of ultrasound imaging." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/96459.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 283-293).<br>Ultrasound is used extensively in medicine to non-invasively examine soft tissues. Compared to computed-tomography (CT) scanning or X-ray imaging, ultrasound is lower-cost, more portable, real time, and subjects neither the caregiver nor the patient to potentially harmful ionizing radiation, which makes it the imaging modality of choice for many medical applications. Common uses include fetal, vascular, and musculoskeletal imaging, as well as biopsy needle insertion guidance. With 165 million ultrasound exams conducted in the United States annually, and an annual US market of $1.3 billion, improvements to the usability and diagnostic capabilities of ultrasound imaging could lead to significant improvements in medical care. Ultrasound is unique because it generally requires significant contact force with the patient. This has a number of important consequences. The contact forces exerted by the ultrasound probe are generally not known, resulting in images that are acquired at non-repeatable levels of compression, which makes sequentially-acquired ultrasound images difficult to compare and reproduce. Contact force has also been implicated as a major risk factor in work-related musculoskeletal disease (WRMSD) amongst ultrasonographers; currently, clinical reports indicate that nearly 90% of sonographers scan in pain. This thesis explores the mechanical design and experimental evaluation of three novel electro-mechanical systems that could be used to enhance the usability and diagnostic capabilities of ultrasound by measuring and/or controlling probe acquisition state (i.e., contact forces, torques, and angles of orientation). The first system, a hand-held servo-driven ball screw stage, improves image repeatability by applying a constant, programmable contact force between the probe and the patient, and attenuates hand tremors by a factor of 10. The second system, a force/torque-measuring ultrasound probe, was used in the first rigorous clinical study to characterize contact forces and torques applied during abdominal scanning. The third device, driven by a voice coil motor, enables high-bandwidth constant force scanning, and was used to measure the elastic modulus of tissue-an indicator of tissue health-at repeatable pre-load forces.<br>by Matthew Wright Gilbertson.<br>Ph. D.
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Nassuphis, Nick I. "A laser-assisted microchemistry system for the fabrication of small electromechanical devices." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36928.
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Turnbull, Ross G. "Sensitivity enhancement in micro-electromechanical systems for sensor applications." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:6d863c2f-532f-40fc-b34a-0f877225c8bc.
Full textAbstract:
Micro-mechanical sensors are typically fabricated both in large numbers and economically using the photolithographic processes that were originally developed in the integrated circuit industry. The magnitude of a change in resonant frequency of a micro-me chanical structure can be used to quantify a change in mass of such a device. Hence, when packaged with integrated measurement, actuation and control electronics, it is possible to deliver a low-cost and small system in a package using fabrication techniq ues that are both mature and widely available. A micro-mechanical resonator has been designed for this project and samples of the prototype resonator were used to investigate various methods for detecting a change in resonant frequency using discrete elec tronic components. The system that has been designed can eventually be integrated with a small micro-mechanical structure to create a mass sensor. Resonators have been fabricated at QinetiQ as part of the Europractice Foundry Access Program and characteri sation of typical devices is described in this thesis. A popular method for controlling the behaviour of resonant micro-mechanical sensors is a force feedback technique designed to increase the effective quality factor of the resonant system. In this thesis, an increase in the effective quality factor of the prototype system has been demonstrated. When the resonator operates in air at atmospheric pressure, an improvement in the effective quality factor of two orders of magnitude was achievable. This meant that it was possible to assess the potential benefits offered by the force feedback technique by testing the various detection schemes that have been implemented at the natural quality factor and also at a high effective quality factor. A prototype control system has been built using simple digital electroni cs, a key component of which is a direct digital frequency synthesis chip used to provide a stable and accurate driving frequency. Methods for determining a change in the resonant frequency of a micro-mechanical resonator using this control system have be en investigated. A method has been developed for determining the magnitude of a shift in resonance when the frequency of the excitation force is fixed. This thesis contains a description of the technique and also results demonstrating the corresponding de tection capability of the prototype sensor.