Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1926. / performed by Shantanu L. Kirloskar. / B.S.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007. / Includes bibliographical references (leaves 58-59). / Mutation detection within the human genome is becoming an increasingly important field today. It is possible that with a correlation between diseases and the mutations that cause them, new therapeutic treatments could be developed against many of today's common diseases In order to accomplish mutation detection, 1012 gene segments may be needed, requiring a significant increase in current technologies An instrument termed an Ultra-high throughput mutational spectrometer (UTMS) uses a process known as constant denaturing capillary electrophoresis (CDCE) to detect mutations in 10,000 capillaries simultaneously. The UTMS is at a 100-capillary proof of concept stage to successfully perform CDCE. In order for this stage to be successful, multiple subsystems of the device must work in unison, including thermal control, optical detection, electrical and fluidic connectivity. In this thesis, multiple devices were created to work in conjunction with previously existing instruments, including a passively aligned 100-port buffer reservoir and DNA injection loading plate. These devices were used to perform electrophoresis on DNA fluorescent primers in order to test the functionality of the UTMS 100-stage concept. / (cont.) A procedure for performing these experiments was developed in order to minimize risk and maximize chance of success. Successful isolation of individual signal detection was accomplished through the use of these procedures and devices, proving the 100-capillary proof of concept may reliably and repeatedly perform CDCE on the UTMS. / by Michael J. Beltran. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. / Includes bibliographical references (p. 24). / The goal on this thesis project was to develop a novel, easy-clean protein shaker. Protein shakers are used to contain and mix protein supplementation powder and water or liquid of the user's choice. Due to the nature of products within the fitness theme, shakers should be easy to use and low maintenance. Significant problems with current protein shakers are bacteria build-up in hard-to-reach places, low quality seals, mouthpiece caps separating from the shaker, and unsatisfactory mixing. Therefore, the goal of this project was to design and prototype a protein shaker that would be easy to clean, preventing unnecessary bacteria build-up in hard-to-reach locations in the shaker. In order to identify the needs of shaker users, an investigation into what current shaker users believed important in a product was conducted. A new design that eliminated all corners and crevasses was proposed and a prototype was constructed using rapid prototyping technology. The prototype provided further insight to additional improvements that could be made to the design. The goal of being easy to clean was successfully achieved. / by Donald R. Lancaster. / S.B.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009. / Includes bibliographical references (leaves 103-106). / The objective of this thesis was to determine the motions needed in a prosthesis that would enable a transhumeral amputee professional golfer, Michael Gibson, to play golf with similar dynamics to those of a two-armed golfer. Although he plays golf well using only one arm, his swings tend to have less power and are less consistent than his two-armed colleagues. Significant user testing was carried out using various prototypes with Gibson. Analysis was performed with Gibson's feedback, video comparisons of swings, and data from both motion capture and flight analysis software. Not only were differences in the dynamics of Gibson's swing and a two-armed golfer's swing studied, but the root causes of the differences were understood. It was determined that a prosthesis that enables wrist cock, forearm rotation, and slight elbow compliance would increase Gibson's golf performance. / by Helen Tsai. / S.M.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 58). / This research creates a system to help PDAP Electronics Singapore control its inventories and achieve demand-driven production on a multiple-product production line. One stage is chosen for study in this thesis. An inventory supermarket combined with a Kanban visualization system is proposed to control the total inventories and schedule production. An ANOVA test is used to first decide the seasonality of demand. Then the inventory levels of the supermarket during each season are determined respectively using the safety stock model. The Kanban system will record the inventory and demand levels and direct daily production accordingly. The simulation results show that the proposed system is capable of controlling the inventory levels and delivering high customer service levels (>95%) at the studied stage. In addition, it could reduce the inventory cost of selected products by 10-15%. It is also suggested that the use of small batch sizes in production will significantly reduce the total inventory cost at the stage. The performance of the system also proves satisfactory in a multi-stage simulation. It is therefore recommended that PDAP implement and further fine-tune this system in its operation. / by Yuan Zhong. / M.Eng.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999. / Includes bibliographical references (p. 84-89). / Deposition of molten microdroplets is fundamental to many emerging droplet-based manufacturing (DBM) processes. Although the spreading behavior of ordinary liquid and molten droplets has been studied extensively for years, some basic questions remain unanswered. Specifically, the fundamental mechanisms of abnormal spreading behavior, such as splashing and bouncing, have yet to be satisfactorily addressed. An understanding of these mechanisms is essential to determine the optimal deposition conditions for the DBM process. This thesis investigates the fundamental, but poorly understood, behavior of liquid and molten metal droplets upon impact on solid surfaces. The splashing of liquid droplets is addressed first. A linear perturbation theory is developed for the interface instabilities of a radially-expanding, liquid sheet in cylindrical geometries. The theory is then applied to rapidly spreading droplets as the fundamental mechanism behind splashing. The effects of such factors as the transient profile of the interface radius, the perturbation onset time, and the Weber number on the analysis results are examined. The analysis shows that the wave number of maximum instability does not remain constant but rather, changes during spreading because of time-dependent coefficients in the amplitude equation. A large impact inertia, associated with a high Weber number, promotes interface instability and prefers high wave number for maximum instability. The next stage investigates the oscillations of liquid droplets upon collision with solid surfaces as a prerequisite for understanding droplet bouncing. Experiments using a high speed video system show that the droplets with higher impact inertia oscillate more vigorously upon collision. The oscillation is strongly affected by the wetting between the liquid droplet and the solid surface, such that the oscillation is greatly promoted in poor wetting conditions. In addition, this thesis develops approximate models based on the variational principle, rather than the Navier-Stokes equation to simulate the droplet oscillation. The results of the models are in good agreement with the experimental data. The analysis shows that the relative magnitudes of surface energy and viscous dissipation play critical roles in determining droplet dynamics. Following the oscillation study, the bouncing of molten metal droplets upon collision with subcooled target surfaces is studied. To determine the conditions for bouncing and sticking, an empirical regime map is constructed using an approximate model and extensive experimental data. A clear trend develops, illustrating that bouncing occurs when solidification is slow compared to oscillation, when a molten metal droplet collides with a non-wetting surface. It is also found that bouncing is prohibited by good wetting between the droplet and the target, which suggests that the wetting be an additional parameter affecting the bouncing behavior. / by Ho-Young Kim. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 37-38). / The Osney Laboratory sought to create an entropy noise test rig that could determine the relationship between entropy noise and the flow parameters of temperature change and nozzle Mach number. The apparatus simulates entropy noise in an aero engine. In the test rig, compressed air enters an anechoic labyrinth, flows through a settling chamber that straightens airflow, and then goes to the entropy wave generator. The entropy wave generator forms entropy waves through electric heating. Entropy waves are then accelerated in a convergent-divergent nozzle to produce entropy noise. Microphones at the end of the rig detect entropy noise readings as acoustic sound. Air exits through an anechoic termination. The test rig allows for easy changes in temperature and Mach number so variation in entropy noise with different input values can be tested. Project stages include literature compilation, 3D computer-aided design, part revision, material specification, and finally supervision of manufacture. / by Mariah I. Hake. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003. / Includes bibliographical references (leaves 159-163). / (cont.) At low load, oil flowing past by the piston was found to be the major consumption source, while the contributions of oil evaporation and of blowby entrainment became more significant with increasing engine load. Furthermore, an extensive study was conducted to measure and analyze the oil consumption behavior during engine load transients to simulate real driving conditions. This work is an important step in advancing the understanding of oil consumption sources in spark ignition engines. / Engine oil consumption is an important source of hydrocarbon and particulate emissions in automotive engines. In addition, chemical compounds present in oil additives poison catalytic converters and reduce their conversion efficiency. As a part of the effort to comply with increasingly stringent emission standards, engine manufacturers strive to minimize engine oil consumption. This requires the advancement of the understanding of the characteristics, sources, and driving mechanisms of oil consumption. There is a general lack of oil consumption studies that connect comprehensive experiments and theoretical analysis. In this work, a combined theoretical and experimental approach was used to separate and quantify different oil consumption sources in a production spark ignition engine at different engine operating conditions. An extensive diagnostic system was successfully implemented on the test engine to measure real time oil consumption and in-cylinder parameters that affect major consumption sources such as inter-ring pressures, oil film thickness in the piston-ring-pack, and liner temperatures. A multi-species liner evaporation model was developed and verified by testing two oils with different volatility at varying cylinder liner temperatures and engine speed and load conditions. The experimental and modeling results were used to separate and quantify the contributions of oil evaporation, oil entrained in the blowby gas flow, and oil flow into the combustion chamber passing by the piston system to total engine oil consumption. The results show that the contribution of each consumption source varies with engine operating conditions. / by Ertan Yilmaz. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001. / Leaves 148 and 149 blank. / Includes bibliographical references (leaves 144-147). / A new all-additive method for direct fabrication of nanometer-scale planar and multilayer structures using the probe tip of an atomic force microscope (AFM) and a material reservoir is proposed. The process, which is called Pick-and-Place NanoAssembly, enables true "pick-and-place" retrieval and deposition of materials with a wide range of electrical, chemical, and mechanical properties. The silicon tip of an AFM is used to discretely pick up molecules from a reservoir, transfer them to a construction zone, and then weld them to a surface. Unlike the prior art, this assembly method offers high-resolution direct patterning of a variety of materials, many of which are not amenable to patterning using current probe-based or conventional lithography methods. Metal nanoparticles, polymers, inks, solvents, and organics have been deposited onto a variety of substrates with resolutions approaching 1 million dots per inch (1 trillion dots per square inch). Lines of nanoparticles have been deposited with line widths of less than 17 nm. These materials can be assembled using reservoirs of viscous liquids, non-viscous liquids, and soft solids. Deposited volumes span a range of 10 orders of magnitude from 10-24 to 10-14 liters. Structures with dimensions of 60 to 100 nm are common. / he patterning process is capable of creating structures with height-to-width aspect ratios of better than 1-to-2, and is relatively insensitive to fluctuations in temperature (3 - 30 C) and humidity (0% - 90%). Methods for the fabrication of multi-layer structures and routes towards true three-dimensional structures are also introduced. It is anticipated that Pick-and-Place NanoAssembly will be suitable for precision deposition and direct patterning of a wide range of useful materials including semiconductors and biological compounds such as DNA. This technique promises to be an enabling tool for biological, chemical, and molecular electronics applications throughout the field of nanotechnology. Near-term applications may include the fabrication of ultra-high density gene chips, high-capacity nano-patterned magnetic disk drives, and single electron transistors. / Brian N. Hubert. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 40). / Hands-on learning remains a key aspect of the educational path through MIT. It provides the practical experience and real-world tie-in that theoretical study and analysis alone could not uphold. Thus, it is necessary to ensure that a lack of lab resources, space, and time do not present barriers to prospective students. As such, the portable FlexLab/LevLab module serves to bring laboratory teaching beyond the lab. This paper presents the results of efforts to redesign the FlexLab portion's cantilever beam to meet two design goals. First of all, that the frequency of the second natural mode of the beam fall below 100 Hz. Second, that the beam's damping is increased such that the first peak gain is within an order of magnitude of the surrounding gain. After testing, a new beam geometry and damping mechanism that satisfied both goals is proposed. / by Christopher Harmon. / S.B.