Dissertations / Theses on the topic 'Mechanical'
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Marcucci, Lorenzo. "A mechanical model of muscle mechanics." Phd thesis, Ecole Polytechnique X, 2009. http://pastel.archives-ouvertes.fr/pastel-00004880.
Full textMatek, Christian C. A. "Statistical mechanics of nucleic acids under mechanical stress." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:ce44cf50-2001-4f54-8e57-d1757f709fd6.
Full textPorro, Cristina Shino. "Quantum mechanical/molecular mechanics studies of Cytochrome P450BM3." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/quantum-mechanical--molecular-mechanics-studies-of-cytochrome-p450bm3(ad4255e7-b779-47a2-a2c5-8dbf6b603ca5).html.
Full textGuillou, Lionel. "Cell Mechanics : Mechanical Properties and Membrane Rupture Criteria." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX041/document.
Full textAtherosclerosis is a chronic disease of the arteries that is a major cause of heart attacks and strokes. This thesis aims to provide novel insight into this disease by looking at specific factors involved in its development from a mechanical standpoint.Two important cell types involved in the development and progression of atherosclerosis are adherent endothelial cells and non-adherent leukocytes (white blood cells). We developed two devices that are able to measure the mechanical properties of both of these cell types. The first one, termed “profile microindentation”, uses micropipettes and microindenters to indent the cell, while the second one uses microfluidics to submit cells to an extensional stress.Further, we wondered if mechanics could help us understand when deformations undergone by cells, or stresses exerted on them, could become harmful.As a matter of fact, when atherosclerotic plaques occlude too much of the blood flow, the most common treatment consists of reopening the vessel with a balloon and keeping it open with a tubular wired mesh called a stent. This procedure exerts considerable compressive stress on the endothelium and is known to be associated with extensive endothelial damage. Hence, we seek to find a physical criterion that is predictive of endothelial cell membrane rupture under compression and to compare this to the stress exerted on the endothelium during the stenting procedure, to see if endothelial damage could potentially be avoided.Similarly, we seek to obtain a physical criterion that is predictive of leukocyte membrane rupture. We then compare and contrast the maximum possible deformations of leukocytes depending on whether those deformations are passive (such as when going through the microvasculature) or active (such as when leukocytes traverse the endothelial barrier)
Miao, Yuyang. "Mechanics of textile composites : from geometry to mechanical properties /." Search for this dissertation online, 2005. http://wwwlib.umi.com/cr/ksu/main.
Full textBlackstone, Britani Nicole. "Biomaterial, Mechanical and Molecular Strategies to Control Skin Mechanics." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406123409.
Full textLai, Jiun-Yu. "Mechanics, mechanisms, and modeling of the chemical mechanical polishing process." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8860.
Full textIncludes bibliographical references.
The ever-increasing demand for high-performance microelectronic devices has motivated the semiconductor industry to design and manufacture Ultra-Large-Scale Integrated (ULSI) circuits with smaller feature size, higher resolution, denser packing, and multi-layer interconnects. The ULSI technology places stringent demands on global planarity of the Interlevel Dielectric (ILD) layers. Compared with other planarization techniques, the Chemical Mechanical Polishing (CMP) process produces excellent local and global planarization at low cost. It is thus widely adopted for planarizing inter-level dielectric (silicon dioxide) layers. Moreover, CMP is a critical process for fabricating the Cu damascene patterns, low-k dielectrics, and shallow isolated trenches. The wide range of materials to be polished concurrently or sequentially, however, increases the complexity of CMP and necessitates an understanding of the process fundamentals for optimal process design. This thesis establishes a theoretical framework to relate the process parameters to the different wafer/pad contact modes to study the behavior of wafer-scale polishing. Several models of polishing - microcutting, brittle fracture, surface melting and burnishing - are reviewed. Blanket wafers coated with a wide range of materials are polished to verify the models. Plastic deformation is identified as the dominant mechanism of material removal in fine abrasive polishing.
(cont.) Additionally, contact mechanics models, which relate the pressure distribution to the pattern geometry and pad elastic properties, explain the die-scale variation of material removal rate (MRR) on pattern geometry. The pad displacement into low features of submicron lines is less than 0.1 nm. Hence the applied load is only carried by the high features, and the pressure on high features increases with the area fraction of interconnects. Experiments study the effects of pattern geometry on the rates of pattern planarization, oxide overpolishing and Cu dishing. It was observed that Cu dishing of submicron features is less than 20 nm and contributes less to surface non-uniformity than does oxide overpolishing. Finally, a novel in situ detection technique, based on the change of the reflectance of the patterned surface at different polishing stages, is developed to detect the process endpoint and minimize overpolishing. Models that employ light scattering theory and statistical treatment correlate the sampled reflectance with the surface topography and Cu area fraction for detecting the process regime and endpoint. The experimental results agree well with the endpoint detection schemes predicted by the models.
by Jiun-Yu Lai.
Ph.D.
Liu, Guoning. "Application of fracture mechanics in electrical/mechanical failures of dielectrics /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20LIU.
Full textJonsson, Anders. "Integral equation methods for fracture mechanics and micro-mechanical problems." Doctoral thesis, KTH, Solid Mechanics, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3336.
Full textLevert, Joseph Albert. "Interface mechanics of chemical mechanical polishing for integrated circuit planarization." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15914.
Full textSvantesson, Cecilia. "Respiratory mechanics during mechanical ventilation in health and in disease." Lund : Dept. of Clinical Psychology, Lund University, 1997. http://catalog.hathitrust.org/api/volumes/oclc/38987113.html.
Full textKleinauskas, Marius. "Dviračio vairo statinio stiprumo ir standumo tyrimai." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060614_011209-33463.
Full textKlasmer, Gabriel. "Assassin : mechanical painting in the post mechanical age." Thesis, Royal College of Art, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534689.
Full textKatiyar, Pushkar. "PROCESSING, MICROSTRUCTURAL AND MECHANICAL CHARACTERIZATION OF MECHANICALLY ALLOYED Al-Al2O3 NANOCOMPOSITES." Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4496.
Full textM.S.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Materials Science and Engineering
Wolff, Lars, and Klaus Kroy. "Mechanical stability." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-190323.
Full textDahlin, Sanna, and Henrik Fagerlund. "Mechanical Mirror." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296234.
Full textDetta kanidatexamensarbete har syftet att presentera en översikt av de steg som genomfördes för att konstruera och programmera en prototyp av en mekanisk spegel. Idén med en mekanisk spegel är att en kamera läser in en bild som sedan är översatt till pixlar med olika värden på ljusstyrka. Dessa ljusstyrkor visas sedan av metallplattor, vilka agerar som pixlar, som roterar till olika vinklar för att reflektera motsvarande ljus från en lampa. Pixlarna formar tillsammans gråskalebilder baserat på de bilder som kameran läser in. En prototyp konstruerades framgångsrikt. Test visade att dess syfte att röra sig i enlighet med den inlästa bilden uppfylldes, dock finns plats för justeringar för att ljuset från lampan ska nå pixlarna i större utsträckning. Pixlarnas vinkelomfång visade sig bli mellan 32°och 44°, vilket konstaterades vara tillräckligt för deras syfte. Skillnaden i vinkelomfång mellan pixlarna berodde på mindre konstruktionsfel och påverkade inte spegelns funktionalitet. Spegelns uppdateringsfrekvens, vilket kan beskrivas som frekvensen med vilken pixlarna roterar och formar en bild, sattes till 25 bilder per sekund. Detta tillät spegeln att härma rörelser framför den utan stor fördröjning utan att överstiga kamerans bildhastighet, som läser in med en bildhastighet på 30 bilder per sekund. Kameran var således den begränsade faktorn för pixlarnas uppdateringsfrekvens.
Sheeter, Eric. "Mechanical silviculture." Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/10527.
Full textYue, Peng. "A micro mechanical study of critical state soil mechanics using DEM." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/38060/.
Full textZhang, Qiuting. "Mechanics and Functionality of Extreme Mechanical Instabilities through Buckling Driven Delamination." Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/587760.
Full textPh.D.
Mechanical instabilities such as wrinkling and buckling-driven delamination in thin film-substrate systems have historically been considered as one of structural failure mechanisms, which should be avoided. The past decade has witnesssed rapid growth in harnessing such surface instabilities for a wide range of tunable surface related properties and functionalities, especially in soft materials on small scales. Compared to extensively studied wrinkling on soft substrates and localized buckling driven delamination on stiff substrates, the fundamental mechanics underpinning ordered buckle-delamination on soft substrate over large area and its guidance for potential implications in engineering innovation remain largely to be explored. This thesis aims to partially bridging such a knowledge gap. In this thesis, I exploit how to generate the controllable and globally periodic delaminated buckling patterns in thin films on highly prestrained elastomeric substrates, and then explore the fundamental mechanics of this spontaneous extreme buckling driven periodic delamination, as well as its implications in design of extremely stretchable electronics and interfacial mechanical properties measurement. Compared to wrinkling, one of the benefits of extremely buckling driven delamination is the extraordinarily high aspect ratio of buckles. The large surface roughness and high local curvature could potentially enable extreme surface topographies related properties, such as adhesion, wetting, friction, and optics, as well as augment the extreme stretchability in stretchable optical and electronic devices. In the aim of harnessing this extreme buckling driven delamination, I first explore the formation and evolution of extraordinarily high-aspect-ratio delaminated buckles of thin films on 400% pre-strained elastomers, as well as uncovered the underlying deformation mechanism through combining quantitative theoretical analysis and experimental and numerical approaches. A theoretical framework is developed to describe the formation and evolution process of periodic delaminated buckles, which includes three deformation stages, i.e. onset of localized blisters (Stage I), growth and propagation of delamination (Stage II), and post-buckling after delamination arrest (Stage III). I show that under extreme large compressive strain, the profile of periodic blisters changes from sinusoidal shape to jig-saw-like shape with relative high aspect ratio, which have potential applications for design of extremely stretchable electronics. Equipped with the fundamental mechanics of buckle-delamination in thin films, I then exploit harnessing the spontaneous buckling driven periodic delamination to achieve high stretchability in both metal and silicon films. Experimentally I observe periodic buckle-delaminated patterns over large area, accompanied by highly ordered transversely cracking patterns, which can be theoretically predicted by simple crack fragments model. I hypothesize that when the width of ribbons is set to be equal or smaller than the theoretically predicted crack fragment width, there would be no cracking fragmentation. This criteria for designing crack-free micro-ribbons is further validated by related experiments. Guided by the validated criteria, I successfully design crack-free and spontaneous delaminated ribbons on highly prestrained elastomer substrates, which provides a high stretchability of about 120% and 400% in Si and Au ribbons, respectively. I further extend the buckling instability-based metrology to systematically measure the mechanical properties of 2D organic conjugated polymer nano-films, which have tremendous promising applications in organic integrated circuits, solar cells, and stretchable devices. I develop a new fabrication strategy to generate buckle-delaminated free-standing organic conjugated polymeric (P3BT/C60) nanosheets. Through both experiments and theoretical analysis, I show that the free-standing buckle-delaminated organic P3BT/C60 nanosheets have significant advantages over the traditional spin-coated wrinkled nanosheets, including the enhanced mechanical properties, a higher level of stretchability with lower electrical resistance, and a wider range of controllable wettability modulation.
Temple University--Theses
Schöneboom, Jan Claasen Curd. "Combined quantum mechanical - molecular mechanical calculations on cytochrome P450cam." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968865267.
Full textShan, Lei. "Mechanical interactions at the interface of chemical mechanical polishing." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/17774.
Full textLoveless, Thomas A. "Mechanical Properties of Kenaf Composites Using Dynamic Mechanical Analysis." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4310.
Full textSjölin, Malin. "Mechanical and chemical chip pre-treatment in mechanical pulp production." Thesis, Linköping University, The Department of Physics, Chemistry and Biology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15169.
Full text
The mechanical pulping industry has been developing throughout the years, due to competitive prices in the electricity market and good accessibility of wood. This has made it possible for such and “expensive” process to further develop. Today, with increasing electricity prizes, it is of great interest to reduce electrical consumption in mechanical pulping industry, since the process consumes large amounts of electricity. Braviken paper mill is starting up a new thermomechanical pulping line, scheduled for start-up in August 2008, which aims to reduce electrical consumption. The new line will include chip pre-treatment equipment such as an impregnator, an Andrtiz Impressafiner (Screw press), a high intensity primary stage refines double disc (DD), and a new low consistency refiner (LC), significantly bigger than those earlier available on the market. This master´s thesis is one out of three Master´s thesis made at Braviken paper mill during spring 2008. They all are connected, and are investigating the possibility to reduce electric energy consumption within TMP production. Master´s thesis concerning high consistency refining was done by Dino Muhic, “High consistency refining of mechanical pulps during varying refining conditions”, and low consistency refining written by Fredrik Johansson “Increased energy efficiency in low consistency refining”.
Chip pre-treatment is to be used to reduce electrical consumption. Mechanical pre-treatment, such as using an Andrtiz Impressafiner demolishes the chips while also making it possible to impregnate the chips with chemicals, the later giving additional possibilities to reduce electricity consumption. Chemical chip pre-treatment decreases the lignin softening temperature, which benefits the refining process, yielding longer and less damaged fibers that will create a fibrous pulp with reduced electrical energy input.The goal for this study was to investigate the effect of alkaline-peroxide on chip pre-treatment by using a design of experiment method, in terms of electric energy consumption for the process, strength properties, opacity and ISO-brightness within the pulp/sheets. The trials were built up as a factorial experiment, with two factors, alkaline and peroxide, with two levels each (high and low). The high level for alkaline was 15 kg/t and 10 kg/t for the low level, and the high level for peroxide was 10 kg/t and 5 kg/t for the low level. This resulted in four trials with two zero-points, and two reference pulps, one normal TMP, thermomechanical pulp, and the other TMP with pressafiner and water.
The trials showed that adding alkaline-peroxide clearly had an impact on pulp properties, such as increased strength properties, fiber length improvements and less shives could be found in the alkaline-peroxide treated pulps. The yield was highest for the normal TMP, about 99% and it decreased with increasing alkaline addition, the lowest value was achieved for the pulps containing the highest dose of alkaline, about 95%. The optical properties were more or less as expected. Opacity had the highest value for the pulps that had been made from chips with the highest total alkaline level. The ISO brightness was highest for pulps containing low level of alkaline. It could not be decided if the electricity demand had been reduced for the chemically treated pulps; it actually had the opposite effect as expected. The chemically treated pulps demanded a higher SEC, specific energy consumption, compared to the reference pulps. This result could have depended on the small pilot plant high consistency refiners at CTP, Centre technique du papier, Grenoble, France, due to the plate size and what kind of plats that were used. To do trials like this and to be able to draw correct conclusions relevant for a full scale plant, bigger refiners might give a more comparable result. It was clear that the fiber properties had improved, which could be the key to reduce electricity when LE- (low-energy) plates are used in the HC-refiner. A higher intensity could be used and electricity energy could be saved.
Dike, Nnadozie N. F. "Performance of Mechanical and Non-mechanical Connections to GFRP Components." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5187.
Full textID: 031001297; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Title from PDF title page (viewed March 7, 2013).; Thesis (M.S.)--University of Central Florida, 2012.; Includes bibliographical references (p. 80-82).
M.S.
Masters
Civil, Environmental, and Construction Engineering
Engineering and Computer Science
Civil Engineering; Structural and Geotechnical Engineering
Conca, Luca. "Mechanical properties of polymer glasses : Mechanical properties of polymer glasses." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1050/document.
Full textThis manuscript presents recent extensions to the PFVD model, based on the heterogeneity of theh dynamics of glassy polymers at the scale of a few nanometers et solved by 3D numerical simulation, which aim at providing a unified physical description of the mechanical and dynamical properties of glassy polymers during plastic deformation. Three main topics are treated: Plasticization. Under applied deformation, polymers undergo yield at strains of a few percent and stresses of some 10 MPa.We propose that the elastic energy stored at the scale of dynamical heterogeneities accelerates local dynamics. We observe yield stresses of a few 10 MPa are obtained at a few percent of deformation and that plastification is due to a relatively small amount of local yields. It has been observed that dynamics becomes faster and more homogeneous close to yield and that the average mobility attains a stationary value, linear with the strain rate. We propose that stress-induced acceleration of the dynamics enhances the diffusion of monomers from slow domains to fast ones (facilitation mechanism), accelerating local dynamics. This allows for obtaining the homogeneisation of the dynamics, with the same features observed during experiments. Strain-hardening, in highly entangled and cross-linked polymers. At large strain, stress increases with increasing strain, with a characteristic slope (hardening modulus) of order 10 – 100 MPa well below the glass transition. Analogously to a recent theory, we propose that local deformation orients monomers in the drawing direction and slows dows the dynamics, as a consequence of the intensification of local interactions. The hardening moduli mesured, the effect of reticulation and of strain rate are comparable with experimental data. In addition, strain-hardening is found to have a stabilizing effect over strain localization and shear banding
Jenett, Benjamin(Benjamin Eric). "Discrete mechanical metamaterials." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/130610.
Full textCataloged from the official PDF version of thesis.
Includes bibliographical references (pages 127-136).
Digital fabrication enables complex designs to be realized with improved speed, precision, and cost compared to manual techniques. Additive manufacturing, for example, is one of the leading methods for rapid prototyping and near net shape part production. Extension to full scale structures and systems, however, remains a challenge, as cost, speed and performance present orthogonal objectives that are inherently coupled to limited material options, stochastic process errors, and machine-based constraints. To address these issues, this thesis introduces new materials that physically embody attributes of digital systems, scalable methods for automating their assembly, and a portfolio of use cases with novel, full-scale structural and robotic platforms. First, I build on the topic of discrete materials, which showed a finite set of modular parts can be incrementally and reversibly assembled into larger functional structures.
I introduce a new range of attainable properties, such as rigidity, compliance, chirality, and auxetic behavior, all within a consistent manufacturing and assembly framework. These discretely assembled mechanical metamaterials show global continuum properties based on local cellular architectures, resulting in a system with scalability, versatility, and reliability similar to digital communication and computation. Next, I present a new kind of material-robot system to enable methods of assembly automation. Rather than relying on global motion control systems for precision, mobile robots are designed to operate relative to their discrete material environment. By leveraging the embedded metrology of discrete materials, these relative robots have reduced complexity without sacrificing extensibility, enabling the robots to build structures larger and more precise than themselves.
Multi-robot assembly is compared to stationary platforms to show system benefits for cost and throughput at larger scales. Finally, I show a range of discretely assembled systems that blur the boundary between structure and robotics. Full-scale demonstrations include statically reconfigurable bridges, supermileage racecars, and morphing aero and hydrodynamic vehicles. Performance scaling is projected to new regimes, using case studies of turbine blades, airships, and space structures. These discrete systems demonstrate new, disruptive capabilities not possible within the limits of traditional manufacturing.
by Benjamin Eric Jenett.
Ph. D.
Ph.D. Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences
McCrate, Mark P. "Modern Mechanical Automata." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1291146053.
Full textLevin, Ari. "Modelling mechanical systems." Master's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/19420.
Full textOtte, Alexander-Nikolaj. "Combined quantum mechanical, molecular mechanical investigation of enantioselective reactions in lipases." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980565707.
Full textYasuda, Koji, and Daisuke Yamaki. "Simple minimum principle to derive a quantum-mechanical/molecular-mechanical method." American Institute of Physics, 2004. http://hdl.handle.net/2237/8738.
Full textAryaei, Ashkan. "Mechanical Properties of Bio-nanocomposites and Cellular Behavior under Mechanical Stimulation." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1398361357.
Full textShooter, Steven B. "Information modeling in mechanical design : with application to cam mechanical design /." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-155414/.
Full textParker, Eleanor. "Mechanical loading and cartilage physiology." Thesis, University of Westminster, 2011. https://westminsterresearch.westminster.ac.uk/item/8zzqy/mechanical-loading-and-cartilage-physiology.
Full textZhang, Qian. "Isothermal mechanical and thermo-mechanical durability characterization of selected pb-free solders." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/220.
Full textThesis research directed by: Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Sul, Onejae Washburn Michael Sean. "Thermally actuated mechanical systems." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,392.
Full textTitle from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics and Astronomy." Discipline: Physics and Astronomy; Department/School: Physics and Astronomy.
Mow-Lowry, Conor. "Opto-mechanical noise cancellation." View electronic text, 2002. http://eprints.anu.edu.au/documents/disk0/00/00/07/65/index.html.
Full textAvailable via the Australian National University Library Electronic Pre and Post Print Repository. Title from title screen (viewed Mar. 28, 2003). "A thesis submitted for the degree of Bachelor of Science with Honours in physics at the Australian National University" "November 2002" Bibliography: p. 73-75.
Lillehei, Peter Thomas. "Single molecule mechanical testing." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/31044.
Full textWas, Loïc. "Mechanical Engineering for Electronics." Thesis, KTH, Hållfasthetslära (Inst.), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103785.
Full textRadcliffe, Torrey Owen 1974. "Mechanical structures interactive laboratory." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/16833.
Full textIncludes bibliographical references (p. 53-54).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
The Mechanical Structures Interactive Lab is one of a number of new remotely accessible WebLabs being developed at the Massachusetts Institute of Technology. WebLabs allow students access to physical experiments from anywhere at anytime via the World Wide Web. While these cannot replace laboratories that are more traditional, they facilitate lab assignments when traditional labs are not practical. The Mechanical Structures Interactive Laboratory is a framework for allowing remote experimentation on elastic structures. Users of the system are able to obtain data from experiments they perform on the structures form a remote location. The system is designed to allow new experiments to be easily added, and can support all levels of mechanical structures courses currently oered at MIT. The system can be used by multiple courses in multiple departments of multiple universities. Users are only required to have a computer connected to the World Wide Web and they can send actuator commands and monitor sensor responses in near real time. The typical student is expected to spend between fifteen minutes to an hour using the system to obtain experimental data. A queuing system regulates (and allows monitoring of) system usage. All of the software was developed using National Instruments G language. Unlike similar systems, the Mechanical Structures Interactive Lab does not use any sort of Java based applications. The system has been tested in a small graduate course. The students used a piezoelectric actuator to stimulate a beam and monitored the response using strain gauges, laser displacement sensors and a webcam. By using the same computer to both model the beam and perform experiments, the students received rapid feedback on the accuracy of their numerical models. While most of the feedback received was positive, there are still a number of areas for system improvement. While work is still being done to make these improvements, the system has shown itself to be an effective means of providing a positive educational experience to engineering students.
by Torrey Owen Radcliffe.
S.M.
Walsh, Brian Kendall. "Computer-aided mechanical ventilation." Thesis, Rush University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10111109.
Full textStatement of the problem: The systematic implementation of evidence-based practice through the use of guidelines, checklists and protocols has been shown to mitigate the risks associated with MV, yet variation in practice remains prevalent. Recent advances in MV, physiologic monitoring, device-to-device communication, computer processing and software engineering have allowed for the development of an automated point-of-care access to real-time goal setting and practice variance identification. Our aim was to assess the utility of a computer-aided MV (CAMV) system that displays variances and scores the overall MV course. Methods: A retrospective categorization of the ventilation and oxygenation statuses of patients within our pediatric intensive care unit (PICU) over a 2 '/z years period utilizing 15 rule-based algorithms was initiated as a proof of concept. Goals were predetermined based on generally accepted values. All patient categories were calculated and presented as a percent of recording time. Following the feasibility study, a retrospective observational study (baseline), followed by two sequential interventions made over a 2-month period was conducted. Phase I comprised a survey of goals of MV by clinicians caring for patients being monitored by the CAMV system. Phase II intervention was the setting and monitoring of goals of MV with a web browser based data visualization system (T3). An outcome measurement tool was developed to score each MV course. The MV score (MVS) evaluated four outcomes: (1) acceptable ventilation, (2) acceptable oxygenation, (3) barotrauma free and (4) volutrauma-free states as a percent of recording time. Results: Pilot consisted of 222 patients. The Baseline phase evaluated 130 patients, Phase I enrolled 31 patients and Phase II enrolled 36 patients. There were no differences in demographic characteristics between cohorts. One hundred and seventy-one surveys were completed in Phase I. An increase in the use of T3 by 87% was observed in Phase II from Phase I. MVS improved by 8.4% in Phase I and 11.3% in Phase II from Baseline. The largest improvement was in the volutraumafree category. MVS was 9% higher on average in those who survived. Conclusion: The use of CAMV was associated with an improvement in MVS. Further research is needed to determine if improvements in MVS through a targeted, process-oriented intervention such as CAMV will lead to improved patient outcomes.
Howe, Kimberly Palazzo. "Mechanical Ventilation Antioxidant Trial." Case Western Reserve University School of Graduate Studies / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=case1112877564.
Full textChiel, Joshua R. "Natural Mechanical Topological Insulators." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1586315731890489.
Full textVonderheide, Christopher M. "Laser velocimetric flow mapping and characterization of oil mist nozzles used for blade excitation in high cycle fatigue testing." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FVonderheide.pdf.
Full textThesis Advisor(s): Dr. Raymond Shreeve, Dr. Garth Hobson. Includes bibliographical references (p. 61). Also available online.
Fountoukidis, Evangelos. "Thermo-mechanical response of monolithic and NiTi shape memory alloy fiber reinforced Sn-3.8Ag-0.7Cu solder." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FFountoukidis.pdf.
Full textHosoglu, Selcuk. "Cellular automata an approach to wave propagation and fracture mechanics problems." Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion.exe/06Dec%5FHosoglu.pdf.
Full textThesis Advisor(s): Young W. Kwon. "December 2006." Includes bibliographical references (p. 63-64). Also available in print.
Betancourt, Arturo. "Computational study of the heat transfer and fluid structure of a shell and tube heat exchanger." Thesis, Florida Atlantic University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10172609.
Full textA common technique to improve the performance of shell and tube heat exchangers (STHE) is by redirecting the flow in the shell side with a series of baffles. A key aspect in this technique is to understand the interaction of the fluid dynamics and heat transfer. Computational fluid dynamics simulations and experiments were performed to analysis the 3-dimensional flow and heat transfer on the shell side of an STHE with and without baffles. Although, it was found that there was a small difference in the average exit temperature between the two cases, the heat transfer coefficient was locally enhanced in the baffled case due to flow structures. The flow in the unbaffled case was highly streamed, while for the baffled case the flow was a highly complex flow with vortex structures formed by the tip of the baffles, the tubes, and the interaction of flow with the shell wall.
Barry, Matthew M. "Analytical and experimental studies of thermoelectric devices and materials." Thesis, University of Pittsburgh, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10183683.
Full textInterest in thermoelectric devices (TEDs) for waste-heat recovery applications has recently increased due to a growing global environmental consciousness and the potential economic benefits of increasing cycle efficiency. Unlike conventional waste-heat recovery systems like the organic Rankine cycle, TEDs are steady-state, scalable apparatus that directly convert a temperature difference into electricity using the Seebeck effect. The benefits of TEDS, namely steady-state operation and scalability, are often outweighed by their low performance in terms of thermal conversion efficiency and power output. To address the issue of poor device performance, this dissertation takes a multi-faceted approach focusing on device modeling, analysis and design and material processing.
First, a complete one-dimensional thermal resistance network is developed to analytically model a TED, including heat exchangers, support structures and thermal and electrical contact resistances. The purpose of analytical modeling is twofold: to introduce an optimization algorithm of the thermoelectric material geometry based upon the realized temperature difference to maximize thermal conversion efficiency and power output; and to identify areas within the conventional TED that can be restructured to allow for a greater temperature difference across the junction and hence increased performance. Additionally, this model incorporates a component on the numerical resolution of radiation view factors within a TED cavity to properly model radiation heat transfer. Results indicate that geometric optimization increases performance upwards of 30% and the hot-side ceramic diminishes realized temperature difference. The resulting analytical model is validated with published numerical and comparable analytical models, and serves as a basis for experimental studies.
Second, an integrated thermoelectric device is presented. The integrated TED is a restructured TED that eliminates the hot-side ceramic and directly incorporates the hot-side heat exchanger into the hot-side interconnector, reducing the thermal resistance between source and hot-side junction. A single-state and multi-stage pin-fin integrated TED are developed and tested experimentally, and the performance characteristics are shown for a wide range of operating fluid temperatures and flow rates. Due to the eliminated to thermal restriction, the integrated TED shows unique performance characteristics in comparison to conventional TED, indicating increased performance.
Finally, a grain-boundary engineering approach to material processing of bulk bismuth telluride (Bi2Te3) is presented. Using uniaxial compaction and sintering techniques, the preferred crystallographic orientation (PCO) and coherency of grains, respectively, are controlled. The effect of sintering temperature on thermoelectric properties, specifically Seebeck coefficient, thermal conductivity and electrical resistivity, are determined for samples which exhibited the highest PCO. It is shown the performance of bulk Bi2Te3 produced by the presented method is comparable to that of nano-structured materials, with a maximum figure of merit of 0.40 attained at 383 K.
Vaidya, Anirudha. "Load-Displacement Relations for an Edge-Cracked Beam with a Hysteretic Bilinear Cohesive Zone Model." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408958644.
Full textCuster, Erica M. "Cortical Bone Mechanics Technology and Quasi-static Mechanical Testing Sensitivity to Bone Collagen Degradation." Ohio University Honors Tutorial College / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1556281791006274.
Full textRigato, Annafrancesca. "Characterization of cell mechanics with atomic force microscopy : Mechanical mapping and high-speed microrheology." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4070/document.
Full textThe field of cell mechanics gained a growing interest because of its fundamental implication in several cellular processes, such as migration, division, differentiation and apoptosis. Among other techniques, atomic force microscopy (AFM) demonstrated particularly useful for the mechanical characterization of living cells. In this thesis, two different aspects were investigated by AFM. In the first part, the elastic properties of epithelial cells grown on adhesive micropatterns were mapped. This study shows that the elasticity of a cell varies as a function of the geometry of its adhesive environment on both global and subcellular scales. The second part of this thesis focuses on the characterization of the viscoelastic response of a cell subjected to an oscillatory mechanical stimulus at high frequency. Previous studies show that the response of cells to such stimuli is mainly dominated by elastic stress and follows a weak power law at low frequency. Instead, a predominantly viscous behavior is expected at high frequency. Up to now, technical limitations prevented the experimental validation of this property. In this thesis, these limitations were overcome thanks to the modification of a high-speed AFM (HS-AFM). With this setup, active rheological measurements of living fibroblasts could be performed from 1 Hz to 120 kHz, extending of two orders of magnitude the frequency scale explored until now. This work highlights a response of cells to high-frequency stimuli which is more viscous than at low frequency, but also suggests a more complex response than expected