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‣ Mechanical engineering at the University of Minho

Flores, Paulo; Seabra, Eurico
Fonte: IEEC2012 Publicador: IEEC2012
Tipo: Conferência ou Objeto de Conferência
Publicado em 03/11/2012 Português
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This paper draws upon research aiming at investigating teaching and learning at higher education within the so-called Bologna Process. It discusses the ways in which students learn at Engineering Education and it analyses their implications for redesigning initial training and rethinking teachers’ role. Data were gathered through interviews and questionnaires. A questionnaire was designed including both closed and open-ended questions. Four levels of information were included: biographic data (gender, age, initial training, current job position, etc), academic education (reasons for choosing Mechanical Engineering, reasons for selecting University of Minho, expectations about Mechanical Engineering course, etc), transition from University to labor market (difficulties faced, scope and nature of the work, etc) and graduate and post-graduate interests (areas, type and organization for high level courses, specific courses, Masters’ and PhD courses). Background characteristics, such as years of experience, academic years of experience at the current job were also included. Overall, findings suggest a positive evaluation of initial training, namely the ways students adapted to university, relationship between students, and length of their practicum. They also highlight a number of issues to be improved: a more hands-on approach...

‣ Flexure based mounts for sensitive payloads : a management and engineering study

Moon, Daniel K. (Daniel Kyeongtaek), 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 52 p.; 8601234 bytes; 8600992 bytes; application/pdf; application/pdf
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by Daniel K. Moon.; Thesis (S.M. and S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.; Includes bibliographical references (p. 51-52).

‣ An integrated method for managing complex engineering projects using the design structure matrix and advanced simulation

Cho, Soo-Haeng, 1975-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 124 p.; 9360808 bytes; 9360566 bytes; application/pdf; application/pdf
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by Soo-Haeng Cho.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.; Includes bibliographical references (p. 101-104).

‣ Blending engineering modeling, industrial design, and physical prototyping in product design

Page, Matthew E. (Matthew Edwin), 1975-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 71 leaves; 4421428 bytes; 4428663 bytes; application/pdf; application/pdf
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by Matthew E. Page.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.; Includes bibliographical references (leaves 63-64).

‣ Understanding estimation and its relation to engineering education

Linder, Benjamin M
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 87 p.; 5152118 bytes; 5162106 bytes; application/pdf; application/pdf
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Benjamin M. Linder.; Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.; Includes bibliographical references (p. 86-87).

‣ Diagnostic indicators for shipboard systems using non-intrusive load monitoring

DeNucci, Thomas W
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 98 leaves; 4572439 bytes; 4576496 bytes; application/pdf; application/pdf
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Field studies have demonstrated that the Non-Intrusive Load monitor (NILM) can provide real-time indication of the condition of electro-mechanical systems on board naval vessels. Results from data collected from engineering systems on board USCGC SENECA (WMEC-906), a 270-foot U.S. Coast Guard cutter, indicate that the NILM can effectively identify faults, failures and deviations from normal operating conditions on numerous shipboard engineering systems. Data collected from the sewage system identified metrics that can be applied, for example, to cycling systems (high pressure air, hydraulic systems, etc.) to differentiate between periods of heavy usage and fault conditions. Sewage system variability and randomness was minimized by employing a MATLAB simulation designed to permit exploration of system behavior that might not have been exposed during other conditions. Simulation data suggests that the presence, location and magnitude of a spike in the pump run distribution indicated the presence of a leak. Data from the actual shipboard system, when subjected to a quantifiable leak, displayed the same behavior. Data collected from the Auxiliary Seawater (ASW) System indicated that the NILM is able to predict the failure of a flexible coupling linking the pump and motor components.; (cont.) The ASW motor-pump system was modeled using a 5th order induction motor simulation to explore the electro-mechanical relationships between the motor...

‣ Processing and thermal properties of molecularly oriented polymers

Skow, Erik (Erik Dean)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 63 p.
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High molecular weight polymers that are linear in molecular construction can be oriented such that some of their physical properties in the oriented direction are enhanced. For over 50 years polymer orientation and processing has been extensively studied to improve the mechanical properties of polymers. In more recent history the anisotropic thermal properties of oriented polymers have been studied. This thesis investigates the thermal properties of Ultra High Molecular Weight Polyethylene (UHMW-PE) and explores applications for the same. This thesis details an effective means of aligning the molecules in bulk polyethylene sheets through stretching in the gel state. Tests have shown that bulk UHMW-PE can be stretched 50-80 times in xylene. The thermal conductivity of bulk UHMW-PE is 0.3 W/mK, while that of a sample stretched 20-25 times is over 4.5 W/mK.; by Erik Skow.; Thesis (S.M. in Mechanical Engineering and Naval Architecture and Marine Engineering)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (p. 61-63).

‣ An investigation of didactic energy transfer systems

Bavetta, Ryan A. (Ryan Andrew)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 51 leaves
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New experiments were developed for the freshmen seminar Physics of Energy. The class covers electricity generation and dissipation, and provides experience in analysis and design of electrical and mechanical engineering systems. There was interest in developing a series of new laboratory experiments that would demonstrate methods of energy conversion to students. The experiments are focused on the topic of energy conversion and they introduce topics from electromagnetism to mechanical engineering. The new systems developed include a DC motor kit for learning about motor design and use, a linear synchronous motor for learning about electromagnetism, classical mechanics and ballistics, and an end to end power plant energy conversion laboratory to introduce the topics of heat transfer and process efficiencies.; by Ryan A. Bavetta.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (leaf 24).

‣ Association of lingual myoarchitecture with local mechanics during swallowing determined by magnetic resonance imaging

Felton, Samuel M., M. Eng. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 135 p.
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The tongue is an intricately configured muscular organ, which undergoes a series of rapid shape changes intended to first configure and then transport the bolus from the oral cavity to the pharynx during swallowing. In order to observe the synergistic interactions of the eight different muscles in the tongue, MRI techniques were used to determine the three-dimensional fiber architecture, measure the mechanical function of the tongue during swallow, and relate the two quantitatively to identify fiber contraction. Diffusion Tensor Imaging was applied to the in vivo tongue of five subjects at rest to image the tongue myoarchitecture. The data revealed the complex relationships between extrinsic and intrinsic fibers. Phase Contrast MRI was applied to ten subjects to assess the complex array of mechanical events occurring during the propulsive phase of swallowing. Physiological strain rate data was acquired in 4 and 6 time point series during approximately 3 ml water bolus swallows. Data acquisition was gated to pressure from the tip of the tongue against the hard palate, indicating the beginning of the irreversible late accommodation. This method demonstrated that the propulsive phase of swallowing is associated with a precisely organized series of compressive and expansive strain rate events. Individual subject data sets from both of these methods were then related. The alignment between local fiber direction and the co-located strain rate tensor was quantified by the dot product between the two vectors. Using this technique...

‣ The engineering case study as a basis for the Master of Science thesis : the Teradyne, Inc. case study : a kinematic interface for semiconductor test equipment; Kinematic interface for semiconductor test equipment

Alagheband, Ali, 1971-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 89 leaves
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by Ali Alagheband.; Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1996.; Includes bibliographical references.

‣ Experiments in service learning

Banzaert, Amy, 1976-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 86 p.
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Service learning, an educational method that involves the application of academic work to projects that benefit under-served communities, was explored in two complementary forms. First, the development of an alternative form of charcoal made from sugarcane agricultural waste is discussed, including product and process characterization and improvement. The motivation for the project is to establish an alternative cooking fuel that is less detrimental than existing options based on three criteria: health risks, environmental impact, and affordability. A method for improving the speed and safety of a critical process step is presented, and initial test findings demonstrate that the product generally matches the cooking parameters of the benchmark, the wood charcoal that this project seeks to replace. Second, the introduction of service learning pedagogy into three core mechanical engineering classes at MIT - 2.002 Mechanics and Materials II, 2.006 Thermo-Fluids Engineering II, and 2.009 Product Engineering Processes - is explored. Curricular materials, service projects, and assessment methods were developed and implemented. Based on initial research, the pedagogy is effective when integrated into the class well, meaning a project was chosen that was academically rigorous and matched both the curricular goals of the class and the needs of the community partner. In addition...

‣ A continuum model for needlepunched nonwoven fabrics; Continuum model for needle punched non woven fabrics

Jearanaisilawong, Petch, 1979-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 166 p.
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Nonwoven fabrics are sheet structures created by bonding or interlocking a web (network) of fibers through mechanical, thermal or chemical processes. In general, the mechanical response of nonwoven fabrics exhibits two major characteristics. First, the mechanical response can vary significantly when the fabric is loaded along different directions, depending on the existence of a preferential orientation in the fiber arrangement and/or in the pattern of inter-fiber bonding/entanglement. Second, the mechanisms of deformation include elastic and inelastic components, accompanied by an irrecoverable evolution of the texture of the fiber network. In this work, we propose a three-dimensional, large strain continuum model for the constitutive behavior of nonwoven fabrics that accounts for the fiber network characteristics responsible for its anisotropic behavior, and captures the effects of deformation mechanisms at the micro-scale (fiber and bonds/entanglement) level. The model consists of two constitutive components: a nonlinear elastic component representing the resistances to recoverable deformation mechanisms, and a non-linear inelastic component representing the resistances to irrecoverable deformation and texture evolution. For nonwoven fabrics in which the anisotropy of fiber orientation is combined with random entanglement processes...

‣ Neural stem cell differentiation in collagen scaffolds for retinal tissue engineering

Ueda, Erica (Erica Ann)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 125 p.
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Rat neural stem cells (NSCs) were cultured in monolayer or in porous collagen scaffolds and exposed to neurogenic or non-neurogenic medium to determine the effects on neural differentiation and neurite growth. Nestin, [beta]III-tubulin, and GFAP expression were determined using immunofluorescent techniques, and the neurite length was measured. NSCs differentiated into neurons, with actively growing neurites, and astrocytes when cultured in differentiation medium (DM) or neurogenic medium (NM). NSCs cultured in monolayer expressed more nestin and III-tubulin and had significantly longer neurite extensions than NSCs cultured in collagen scaffolds. Laminin coated scaffolds promoted the attachment of NSCs to the scaffold struts and resulted in a more even distribution of nestin and [beta]III-tubulin positive cells throughout the scaffold. Overall, NSCs cultured in DM for at least 14 days resulted in the most neuronal differentiation and neurite growth.; by Erica Ueda.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.; Includes bibliographical references (p. 123-125).

‣ Early-stage engineering design : the designer, the object of design, and design context

Roan, Earl Taylor
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 90 p.
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Much of design research has been focused on developing prescriptive design processes, however, proper description of the designer, the object of design, and the context may be lacking (Dorst, 2007). The present research adds insight concerning these three elements through observation of a creative design course with a diverse student composition. The layout of course was built around six very different early-stage design projects. A technique for characterizing and visualizing design projects and tasks is also introduced and used as a tool for describing the objects of design and project contexts. Collected data carried several important implications. One profound result was that no measure of designer experience was significantly correlated with general performance across all design projects. However, less experienced designers actually seemed to do better at more atypical projects, while experienced designers had the upper hand in solving more traditional problems. No other design-related skills correlated consistently with performance. Designers who were confident, however, tended to learn more and enjoy the projects, their teammates, and the teaching staff more. The results raise many important questions for designers, educators...

‣ Summary of Research 2001, Department of Mechanical Engineering

Faculty of the Department of Mechanical Engineering, Naval Postgraduate School
Fonte: Office of the Associate Provost and Dean of Research, Naval Postgraduate School. Publicador: Office of the Associate Provost and Dean of Research, Naval Postgraduate School.
Tipo: Relatório
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The view expressed in this report are those of the authors and do not reflect the official policy or position of the Department of Defense or U.S. Government.; This report contains project summaries ofthe research projects in the Department ofMechanical Engineering. A list ofrecent publications is also included, which consists of conference presentations and publications, books, contributions to books, published journal papers, and technical reports. Thesis abstracts of students advised by faculty in the Department are also included.

‣ Adhesively bonded composite repairs in marine applications and utility model for selection of their nondestructive evaluation

Panagiotidis, Dimitrios
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 124 leaves
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During the last half century, the use of composite materials and structures has been increasing within many industries: aerospace, automotive, civil, marine, and railway engineering, wind power generation, and sporting goods, to name a few. There is, however, only a small open literature base concerning adhesively bonded composite repairs, primarily originating from within the aerospace industry. Moreover, little work has been done toward the optimization of repairs on marine composite structures, despite a growing number of such applications. Few decision-making procedures leading to the undertaking of composite repairs have been articulated. Among these, the selection of the most appropriate nondestructive evaluation (NDE) scheme is acknowledged as an important aspect in determining the extent and the type of repair, and ultimately assessing its quality. Such selections of NDE technique(s) currently appear to be largely based upon qualitative engineering judgment, which is likely to lead to long-term sub-optimal remedies. An open literature review of various repair schemes and the parameters that affect their mechanical properties is undertaken, and conclusions on adhesively bonded composite repairs for marine applications are summarized.; (cont.) Particular attention is given to the effects on the repaired composite of the mechanical and geometric properties of the adhesive and patch materials...

‣ Mechanism-based constitutive modeling of L1₂ single-crystal plasticity

Yin, Yuan, 1977-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 173 leaves
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Ni3Al, an L12 structure intermetallic crystal, is the basic composition of the [gamma]' precipitates in nickel-based superalloys and is a major strengthening mechanism contributing to the superalloys' outstanding high-temperature mechanical properties. Many L12-structure crystals present unusual macroscopic mechanical properties, including the anomalous temperature-dependence of yield strength and strain hardening rate. To date, extensive research has been carried out to reveal the underlying mechanisms. However, none of the resulting models has satisfactorily quantified the macroscopic behavior based on microscopic phenomena. Mechanism-based constitutive modeling and simulation provide an effective method in this respect, assisting in the understanding and development of current existing models, and potentially providing a convenient path for engineering applications. In light of recent theoretical developments and experimental evidence, a single-crystal continuum plasticity model for the L12-structure compound Ni3A1 is developed.; (cont.) Both the superkink-bypassing mechanism and the self-unlocking mechanism have been modified and combined to describe the unlocking of sessile screw dislocations and the deformation-induced evolution of dislocation "states" in the yield anomaly region. The proposed model has been implemented within a finite-element framework to investigate the mechanical properties observed in constant strain-rate uni-axial tension/compression tests. Results of numerical simulations successfully capture major features of the mechanical behavior of Ni3Al-based single crystals...

‣ Evaluation of non-intrusive monitoring for condition based maintenance applications on US Navy propulsion plants

Greene, William C. (William Calvin)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 141 p.; 8007188 bytes; 8013081 bytes; application/pdf; application/pdf
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The thesis explores the use of the Non-intrusive Load Monitor (NILM) in Condition Based Maintenance (CBM) applications on US Navy ships as part of the Office of Naval Research Electric Ship Integration (ESI) Initiative. The NILM is a device that measures an electrical component's performance by applying a single voltage and current transducer to a ship's existing power distribution system. The NILM was originally developed to monitor electrical power usage in buildings where it was noticed that it could disaggregate and report the operation of individual loads when many loads were present. The limits of this capability are explored by employing a signal processing script in MATLAB using component data gathered on the USCGC SENECA (WMEC-906). The plausibility of using a few NILMs to provide machinery monitoring information for an entire engineering space, and the resulting opportunity to reduce sensor growth on future Navy ships is explored. Then efforts to monitor naval propulsion plant machinery with the NILM are discussed. Two NILMs were constructed and installed on selected individual components at the Naval Surface Warfare Center Philadelphia DDG-51 Land Based Engineering Site (LBES).; (cont.) Monitoring of the Fuel Oil and Low Pressure Air Service Systems was conducted during a week long certification of the pre-commissioning crew of the USS BAINBRIDGE (DDG-96). Data collected was then used to explore the use of the NILM as a diagnostic device for shipboard systems through the evaluation of mechanical transients in the Fuel Oil system and a test leak inserted into the Low Pressure Air System. Additionally...

‣ Design and manufacture of an electro-mechanical hand position tracker

Tan, Nicola
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 77 p.
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This thesis discusses the conceptual design, manufacture, and assembly of a device that tracks the movements and position of a user's hand. This device will be used for stroke patients undergoing rehabilitation using robotic aids, monitoring their use of their unimpaired hand, particular when performing bimanual tasks. This device uses a system of linkages and potentiometers to track the angles of the wrist, as well as the MCP and CMC joints of the index finger and the thumb. This allows a simple model of the hand to be constructed on the computer in x, y, and z dimensions. In addition, a base was designed and built to locate the absolute position of the hand in three dimensions. The potentiometers are then connected to a computer where the movements can be viewed.; by Nicola Tan.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (p. 47).

‣ A reverse engineering process for mechanical engineering systems

Tamarez-Gomez, Frank
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
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This thesis presents a literature review of current reverse engineering technologies and processes, with an emphasis on tools commonly used in Software Reverse Engineering (SRE). Using the foundation of the literature review, the thesis will then propose a standard process, referred to as "A Reverse Engineering Process for Mechanical Engineering Systems (REPMES)." The REPMES tool is intended to enable engineers to understand how current products work. Additionally, REPMES may allow engineering design teams to more effectively revise their product designs through competitive benchmarking. The REPMES is illustrated through application to case studies of a consumer flashlight and an automotive torque converter. Unlike the field of Software Reverse Engineering (SRE), there is not currently a published standardized procedure to successfully implement reverse engineering of mechanical engineering systems. The REPMES process introduced here differs from SRE in that the target for SRE is to understand the inner workings of a computer program or system. However, REPMES has to account for the materials used, the limitations of the same materials, the physical conditions under which the system must operate, the mean time between failure, manufacturing processes and tolerances...