Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005. / Includes bibliographical references (leaves 74-76). / Limitations of electrical wires result in distortion and dispersion of the signal for long distances. That have emerged optical communication as the only way of communication for long distances. For medium distances optics can support the high data rates required by the latest applications. Optical networks are becoming the dominant transmission medium as the data rate required by different applications increases. The bottleneck for implementing optical instead of electric networks for medium distances, like local area network, is the cost of the optical components and the cost of replacing the existing copper network. This thesis will discuss the possible cost benefits that come from the use of different materials like plastic optical fiber instead of silica fiber or Si, Si/Ge instead of InP or GaAs for the transceiver as well as the trade offs between the performance and cost when discrete transceiver is replaced by the monolithically integrated transceiver, by using a process based cost model. / by Genta (Meco) Gusho. / M.Eng.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2016. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (pages 175-184). / The objective of this thesis is to uncover the chemical states and atomic structure of the initial oxide on zirconium and the oxygen transport kinetics through this oxide under electric field. This goal is important for enabling more accurate zirconium oxidation models, for example for nuclear reactor materials, as well as for assessing the mechanisms that govern the performance of zirconia based technologies, such as redox based resistive switching memory devices, gate dielectric for metal oxide semiconductor devices, and electrolytes for solid oxide fuel cells ... / by Wen Ma. / Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1988. / On t.p. all "x̳" is subscript. / Includes bibliographical references. / Kimberley Elcess. / Ph.D.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 72-83). / In the last decade, the field of single cell mechanics has emerged with the development of high resolution experimental and computational methods, providing significant amount of information about individual cells instead of the averaged characteristics provided by classical assays from large populations of cells. These single cell mechanical properties correlate closely with the intracellular organelle arrangement and organization, which are determined by load bearing cytoskeleton network comprised of biommolecules. This thesis will assess the feasibility of a high throughput single cell force spectroscopy using an atomic force microscopy (AFM)-based platform. A conventional AFM set-up employs a single cantilever probe for force measurement by using laser to detect the deflection of the cantilever structure, and usually can only handle one cell at a time. To improve the throughput of the device, a modified scheme to make use of cantilever based array is proposed and studied in this project. In addition, to complement the use of AFM array, a novel cell chip design is also presented for the fine positioning of cells in coordination with AFM cantilevers. The advantages and challenges of the system are analyzed too. To assess the feasibility of developing this technology, the commercialization possibility is discussed with intellectual property research, market analysis, cost modeling and supply chain positioning. Conclusion about this technology and its market prospect is drawn at the end of the thesis. / by He Cheng. / M.Eng.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2018. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (pages 408-431). / According to the future of the nuclear fuel cycle study at MIT, a reactor with a conversion ratio around one can achieve desired objectives in the long-term sustainability of uranium and reduction of transuranic wastes. This finding relaxes the need for sodium fast reactors (SFR) in a closed-loop nuclear fuel cycle and enables high-conversion light water reactors (HC-LWR) to be used as an alternative. HC-LWRs have two major advantages over SFRs. First, apart from the reactor core, the remaining reactor system can be based on existing LWR technology. Second, extensive operating experience and a proven record of high reliability of LWRs would ease licensing and commercialization processes. Therefore, operating HC-LWRs instead of SFRs may be more economically and technically viable with lower capital and development cost for the near term. This type of reactor is being developed by Hitachi Ltd. under the name of resource-renewable boiling water reactor (RBWR). This study focuses on RBWR-TB2, transuranic burning version of RBWR. To demonstrate that the RBWR-TB2 can operate safely within design constraints and regulatory limits, the thermomechanical behavior of this reactor has been analyzed through fuel performance modeling. Due to its unique design characteristics, several physical phenomena at high temperature and high burnup typically ignored in most LWR fuel performance codes can potentially become active under RBWR's operating conditions. These phenomena involve migration of fuel constituents and fission products, the evolution of O/M ratio with burnup, high burnup structure (HBS) formation, accelerated corrosion, hot pressing, gaseous fuel swelling, hydride precipitation and hydrogen migration in the cladding. Semi-empirical models describing porosity and cesium migration behaviors have been replaced with mechanistic models. All of these phenomena have been successfully implemented in a modified version of FRAPCON-3.5 known as FRAPCON-3.5 EP where EP stands for enhanced performance. The fuel performance comparison between RBWR-TB2 and ABWR fuel rods suggest that because of high axial peaking factors and relatively flat power history, fuel temperature is significantly higher in fissile zones of the RBWR-TB2 leading to various undesirable effects such as excessive fission gas release and cladding deformation. Local fuel burnup in fissile zones of RBWR-TB2 is multiple times higher than that of ABWR leading to excessive fuel swelling, accelerated cladding oxidation, and PCMI at fissile-blanket interfaces. Even if the RBWR-TB2 has to operate under such demanding conditions with a small margin to fuel melting, a steady-state fuel performance analysis still shows that this reactor can operate safely with an acceptable thermo-mechanical performance. In the future optimization of RBWR-TB2 performance, several fuel design strategies are recommended based on a series of sensitivity studies. The sensitivity study on key design parameters indicates that using annular fuel geometry and more hypostoichiometric fuel (lower O/M ratio) could reduce fuel temperature at high burnup. For better resistance to cladding corrosion and PCMI, it is recommended to increase cladding thickness and decrease fuel density. / by Yanin Sukjai. / Ph. D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2007. / Includes bibliographical references (leaves 84-85). / The United States Nuclear Regulatory Commission is responsible for the safe operation of the United States nuclear power plant fleet, and human reliability analysis forms an important portion of the probabilistic risk assessment that demonstrates the safety of sites. Treatment of post-initiating event human error probabilities by three human reliability analysis methods are compared to determine the strengths and weaknesses of the methodologies and to identify how they may be best used. A Technique for Human Event Analysis (ATHEANA) has a unique approach because it searches and screens for deviation scenarios in addition to the nominal failure cases that most methodologies concentrate on. The quantification method of ATHEANA also differs from most methods because the quantification is dependent on expert elicitation to produce data instead of relying on a database or set of nominal values. The Standardized Plant Analysis Risk Human Reliability Analysis (SPAR-H) method uses eight performance shaping factors to modify nominal values in order to represent the quantification of the specifics of a situation. The Electric Power Research Institute Human Reliability Analysis Calculator is a software package that uses a combination of five methods to calculate human error probabilities. Each model is explained before comparing aspects such as the scope, treatment of time available, performance shaping factors, recovery and documentation. Recommendations for future work include creating a database of values based on the nuclear data and emphasizing the documentation of human reliability analysis methods in the future to improve traceability of the process. / by Phillip E. Dawson. / S.M.

Thesis (S.M. and S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2009. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (p. 123-130). / Surface effects on pool boiling heat transfer and the critical heat flux are well documented but poorly understood. This study investigates the pool boiling characteristics of various fluids, and demonstrates that surface effects can drastically alter the nucleate boiling heat transfer coefficient as well as the critical heat flux. Changes in surface morphology and surface chemistry are suspected to be the primary factors influencing pool boiling heat transfer. The relative impact of surface properties is shown to depend strongly upon the working fluid. To evaluate the effects of chemical constituency and surface texture on the pool boiling of water, nanoparticle thin-film coatings are applied to nickel and stainless steel substrates using the layer-by-layer assembly method. This study shows that such coatings, with thicknesses on the order of one micron or less, are capable of enhancing the critical heat flux of water up to 100%, and enhancing the nucleate boiling heat transfer coefficient over 100%. Through the use of thin-film coatings, the importance of nanoscale surface texture, porosity, and chemical constituency on boiling mechanisms is revealed. Low surface tension dielectric fluids, including a recently developed fluorinated ketone with a low global warming potential, are tested to determine their pool boiling heat transfer capabilities. The potential for nanoparticle-based pool boiling enhancement in well-wetting dielectric fluids is investigated. The role of surface wettability and adhesion tension on the incipience of boiling, nucleate boiling, and critical heat flux are considered. / (cont.) Results indicate that the low global warming potential fluorinated ketone may be a viable alternative in the cooling of electronic devices. Additionally, results demonstrate that enhancement of boiling heat transfer is possible for well-wetting dielectric fluids, with 40% enhancement in the critical heat flux using dilute suspensions of aluminum or silica nanoparticles in the fluorinated ketone. / by Eric Christopher Forrest. / S.M.and S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 34). / Bamboo has received much interest recently as a construction material due to its strength, rapid growth, and abundance in developing nations such as China, India, and Brazil. The main obstacle to the widespread use of bamboo as a structural material is the lack of adequate information on the mechanical properties of bamboo. In this work, the microstructure and mechanical properties of Phyllostachis dulcis bamboo are studied to help produce a model for the mechanical properties of bamboo. Specifically, a linear relationship is established between the density of bamboo samples, which is known to vary radially, and their strength in compression. Nanoindentation of vascular bundles in various positions in bamboo samples revealed that the Young's modulus and hardness of the bundles vary in the radial direction but not around the circumference. The compressive strength of bamboo samples was found to vary from 40 to 95 MPa, while nanoindentation results show the Young's modulus of vascular bundles ranges from 15 to 18 GPa and the hardness ranges from 380 to 530 MPa. / by Michael R. Gerhardt. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 52-56). / Bulk luminescent solar concentrators (LSC) cannot make use of Forster resonance energy transfer (FRET) due to necessarily low dye concentrations. In this thesis, we attempt to present a poly-vinylalcohol (PVA) waveguide containing dye-aggregate polystyrene nanospheres that enable FRET at concentrations below that required for the bulk LSC due to dye confinement. In the aqueous state, the maximum achieved energy transfer efficiency of the dye-doped nanoparticles was found to be 8 7% for lwt%/lwt% doping of Coumarin 1 (C1) and Coumarin 6 (C6). In the solid state, however, energy transfer is lost, reducing to 32.8% and 20.1% respectively for the C1(lwt%)/C6(lwt%) and C1(0.5wt%)/C6(lwt/ ) iterations, respectively. Presumably, the dyes leach out of the polystyrene nanospheres and into the PVA waveguide upon water evaporation during drop casting. / by Ron Rosenberg. / S.B.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / Includes bibliographical references (p. 45-48). / There has been much hype in the research and development of continuous glucose monitoring technologies, driven by the enormous and rapidly expanding glucose monitoring market and the large and growing base of diabetes patients. Continuous glucose monitoring has shown significant benefits over traditional intermittent blood glucose testing in reducing the risks of developing long-term complications associated with diabetes, by maintaining blood glucose concentrations to near-normoglycemic levels and reducing glycemic variability. In this thesis, commercially available continuous glucose monitoring systems as well as those still in development are evaluated. SWOT analysis shows that continuous glucose monitoring has a promising future, but there remain a number of challenges to be overcome, such as accuracy, sensor span, data handling, cost and reimbursement issues. It is concluded that continuous glucose monitoring will be the roadmap for future diabetes management. Ongoing technological advances in continuous glucose monitoring systems will hopefully close the loop for a fully automated artificial pancreas and develop a cure for Type I diabetes. / by Guang Li. / M.Eng.