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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Characterization of Nanotube Buckypaper Manufacturing Process

Unknown Date (has links)
The discovery of single-walled nanotubes (SWNTs) gives an important boost to nanomaterial research. Since the nanotubes have exceptional mechanical, thermal, and electrical properties, they are considered very promising reinforcement materials for developing high performance nanocomposites. One of the effective methods for fabricating nanotube composites is to make nanotubes into buckypaper form (Nanotube Buckypaper). The nanotubes are pre-formed into buckypaper of well-dispersed tube network, so as to control tube dispersion and loading as well as microstructures in the resulting composites. In this research, we characterized the quality of buckypaper with different fabricating parameter combinations, and performed statistical analysis on the quality of the produced buckypapers. A statistical model of the nanotube buckypaper process was developed to investigate the contribution of fabricating parameters, including suspension concentration, sonication level and time, filtration vacuum pressure, and surfactant types on nanotube bundle quality as measured by rope size and pore size. Statistical modeling is also used to estimate the variability associated with manufacturing, the image taken, and the measurement processes. The statistical analysis shows that all the selected factors are influential to the quality of buckypaper, and the interactions between these factors contribute more than the factors themselves. Overall, the selection of surfactant is crucial to the formation of a uniform tube rope network of nanotube buckypaper in both average performance and variability. The microscopy characterization of the nanotube buckypaper samples, designed experiment, and variance components analysis all provide strong evidence that Triton X-100 is the best surfactant in terms of better dispersion effect, higher repeatability and less variability in producing nanotube buckypapers. Therefore, the process of fabricating buckypaper with Triton X-100 is suggested to construct a reliable and repeatable model of nanotube buckypaper process, and the model can be further used to optimize operating parameters and predict the quality of nanotube buckypapers. / A Thesis submitted to the Department of Industrial Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Summer Semester, 2004. / Date of Defense: July 6, 2004. / Buckypaper, Design of Experiment, Nanotube / Includes bibliographical references. / Zhiyong Liang, Professor Co-Directing Thesis; James R. Simpson, Professor Co-Directing Thesis; Ben Wang, Committee Member; Chuck Zhang, Committee Member.
2

Comparative Analysis of the Power Output of Crystalline Photovoltaic (PV) Modules Using Solar Tracking System

Unknown Date (has links)
The focus of this thesis was to employ the use of two widely used types of photovoltaic (PV) modules namely monocrystalline and polycrystalline in a tracking system to determine which produces the greater output and compare these results to those reached by my predecessor, Michael O. Case[Case, 2003]. Several factors affect the overall productivity of a solar system. These include but are not limited to, time of day, time of year, latitude and atmospheric conditions, all of which were dealt with throughout this thesis. The thesis began with the design and assembly of a solar tracking system. This system was used to collect data using monocrystalline and polycrystalline modules in various configurations. The configurations were stationary zero degrees, stationary forty degrees and solar tracking at forty degrees. Once data was acquired, it was entered in to the statistical software "Design Expert V6.0". Statistical analysis was then performed to determine the effect the chosen factors had on the power output of the two types of modules in terms of which type provides greater output and in what configuration. It was determined that the monocrystalline module produces greater power output than its polycrystalline counterpart. A final experiment was set up to determine the mode that produces the greatest power output. The results from the experiment revealed that monocrystalline modules deliver greater power in a tracking configuration. However, it may be necessary to consider the effects of temperature depending on application of these modules. / A Thesis submitted to the Department of Industrial Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Fall Semester, 2006. / Date of Defense: October 15, 2006. / Solar Tracking, Crystalline Photovoltaic, PV / Includes bibliographical references. / Yaw A. Owusu, Professor Directing Thesis; James Simpson, Committee Member; Carl A. Moore, Committee Member.
3

Nonlinear model predictive control of end-use properties in batch reactors under uncertainty /

Valappil, Jaleel, January 2000 (has links)
Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 183-198).
4

Reengineering the process of manufacturing thermal-cryogenics tanks

Lozada, Luis O. January 2001 (has links) (PDF)
Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2001. / Includes bibliographical references.
5

The development of a design system for an engineered-to-order product line /

Dahl, Trygve. January 1997 (has links)
Thesis (Ph. D.)--Lehigh University, 1997. / Includes vita. Bibliography: leaves 388-396.
6

Sonopress engineering techniques for increased efficiency /

Jones, Eric James. January 2007 (has links) (PDF)
Thesis (M.Eng.)--University of Louisville, 2007. / Title and description from thesis home page (viewed May 9, 2007). Department of Industrial Engineering. "April 2007." Includes bibliographical references (p. 85).
7

Investigation of Vartm Processing of High Temperature RP-46 Resin System

Unknown Date (has links)
The advantages of using polymer matrix composites in various applications are very well known throughout many industries. Their introduction and subsequent development since the 1940's has led to major cost savings due to their lightweight and excellent mechanical properties. Off late, product designers have been taking advantage of improved thermal properties (CTE, thermo-oxidative stability) that these composite materials have to offer. This began with the development of PMR-15, a high temperature polyimide resin back in the 1970's. The aerospace industry has increasingly turned towards high temperature polymer matrix composites (HTPMC) to replace other heavier materials in engine components thus improving the thrust to weight of the engine. But, PMR-15 has a major drawback related to high safety standards that are needed during processing. The implementation of these controls during processing resulted in huge costs to the industry. This led to the development of a new polyimide high temperature resin system called RP-46 at NASA Langley research center. RP-46 has excellent thermal and mechanical properties comparable to PMR-15 and is safer to handle due to the absence of the lethal MDA monomer, a carcinogen. This research investigates the issues related to processing of RP-46 resin system using the Vacuum Assisted Resin Transfer Molding (VARTM) process, a cost effective method for manufacturing composite materials. The entire process is setup keeping in consideration the requirement of high temperature environments for processing of RP-46. A number of initial trials helped understand the dynamics of the process and identify critical factors and key parameters. The various laminates that were made were tested for mechanical properties (ASTM D3039 - Tensile strength and modulus) and thermal properties (Dynamic Mechanical Analysis, Thermal Mechanical Analysis, Thermal Gravimetric Analysis) were performed and the results were compared with RP-46 samples made using autoclave processing. Although the VARTM laminates had issues related to void contents and the release of volatiles during the infusion stage of the process, the VARTM process was found to be feasible to make composites with RP-46. / A Thesis submitted to the Department of Industrial Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Spring Semester, 2004. / Date of Defense: April 16, 2004. / High Temperature Composites, VARTM / Includes bibliographical references. / Chuck Zhang, Professor Directing Thesis; Okenwa Okoli, Committee Member; Zhiyong Liang, Committee Member.
8

Continuous Buckypaper Manufacturing Process: Process Investigation and Improvement

Unknown Date (has links)
Carbon nanotubes have excellent electrical, thermal, and mechanical properties as determined theoretically and experimentally. Their properties make them great candidates for use in a number of applications ranging from lightning strike protection for airplanes to computer heat sink. However, carbon nanotubes are incredibly small, with diameters as small as 1nm and just a few micrometers long. The nanoscale size makes carbon nanotubes impractical to be used individually for many industrial purposes, thus methods have been developed to fabricate macroscale networks of carbon nanotubes. The carbon nanotube networks, also called Buckypaper, have showed mechanical, thermal and electrical properties inferior to those of individual nanotubes. Extensive work has been conducted to develop and optimize suitable production methods of producing high quality Buckypaper and enhance their properties. Many approaches are capable of producing a carbon nanotube network, but most are not able to scale up for industrial applications due to size and production rate limitations. This research focuses on two aspects of Buckypaper manufacturing improvements. The first is to test 90 mm samples of Buckypaper disks to determine the impact of each processing parameter on the quality and properties. Statistic analysis was used to reveal the effect of processing parameters. Utilizing these results, a long sample of Buckypaper was produced and examined for property and quality consistency along the sample length, using modified customer-made continuous filter devices. Additionally, long samples with larger width were produced to demonstrate production rate of continuous Buckypaper manufacturing. Through this research it was found that the electrical conductivity of the Buckypaper was affected positively by an increase in sonication pressure. Additionally, increases in pressure and increase in power of sonication led to an increase of Buckypaper strength. Strength and electrical properties of the continuous Buckypaper were considered consistent throughout the length. These results provide essential understanding of the continuous Buckypaper manufacturing process. / A Thesis submitted to the Department of Industrial and Manufacturing Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Summer Semester, 2009. / Date of Defense: July 21, 2009. / Carbon Nanotubes / Includes bibliographical references. / Zhiyong Liang, Professor Directing Thesis; Ben Wang, Committee Member; Chuck Zhang, Committee Member; Arda Vanli, Committee Member.
9

An investigation of the goal programming method

Baumgarten, Edwin Oliver January 2010 (has links)
Digitized by Kansas Correctional Industries
10

Policy formulation for a cigarette manufacturing company : a dynamic system simulation

Macropulos, George Manuel January 2011 (has links)
Digitized by Kansas Correctional Industries

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