Theses and Dissertations

Polylactic acid (PLA) is perhaps one of the best known polymers produced from renewable raw materials such as sugar cane and corn starch. Several studies have focused on improving the properties of PLA by incorporating nanofillers in polymer matrix. Cellulose nanocrystals (CNC) is a nanofiller from natural sources (typically wood pulp) that is used to reinforce and modify the mechanical properties and biodegradability of PLA.

The stamping process, of which the punching process is a major division, is one of the most important metal parts production methods in industry. Punching dies are the heart of the punching process. Die performance, as measured by the number of strokes between sharpenings and/or repairs, determines the important per part costs of die depletion and maintenance. Existing quantitative studies are principally on tool wear and punchability.

This hypothesis: a direct correlation exists between methods changes and related productivity changes in non machine-controlled work situations, appeared to be at the root of many problems in applied work measurement. Therefore, the author decided to conduct an objective, quantitative analysis of its validity.

The fundamental relationships among the design parameters of an information system and the utility of the information that a system produces are analyzed in an effort to develop a methodology for measuring the utility of information. The utility of the information is defined as a measure of the effectiveness with which the information can be employed to attain the objectives of the using organization.

The purpose of this research was to further the investigation into GERT output distributions. From the family of GERT networks containing only Exclusive-Or nodes, a generally applicable network form was chosen for simulation. A generalized computer program was written to simulate any specific network of this form.

The solutions to the problems of production forecasting, scheduling, and in-process inventory control for high volume multi-product manufacturing lines are not readily available in current industrial literature. This study proposes simulation as a general approach to solving these problems and proceeds to develop a simulator which is applied to just such a high volume line.

The building industry is perhaps the most fragmented large industrial complex in the country today. Consumers are expressing needs for faster delivery for more functional and sophisticated space at more reasonalble prices. At the same time, the industry in itself is faced with growing internal problems which are making it increasingly more difficult to perform even as well as in the past. This study investigates the area of utility sub-systems in the building industry.

Utilizing CRAFT an optimum plant layout with regard to all products manufactured can be realized. In addition, two manufacturing policies; related to production and inventory control, will be investigated with respect to the effect of said policies on plant layout.

Computational efficiencies of the primal-dual algorithm and the uv-method in solving transportation problems are compared in this thesis. A computer program was written in Fortran IV and run on the CDC 6400 system; it generated random problems with integer constants ranging in the size from 5X10 to 30 X 50, and solved them by both methods.

This is a result of an initial investigation to simplify feedback controllers for stochastic processes. The investigation concerns itself with incrimental control as opposed to proportional control.

This paper concerns itself with quantification of the intangible factors in Product Design Decisions where there is one very big supplier with one very big customer and a unique product. The product design is represented as a state diagram, or curve, with Time as one axis and Product or Material State as the other. Industry affects the product design curve with various levels of decisions. This paper describes four of these levels and investigates a case in which three levels are involved.

A simulation program is presented that develops a risk profile of the intended investment. The risk profile is essentially a return on investment probability analysis developed from the estimated distributions of costs, service life and savings of the intended investment in a computer based, on-line system.

An investigation of the feasibility of applying linear programming to assembly line balancing problems is presented. Salveson and Bowman developed the mathematical models.

Hexagonal Boron Nitride has been shown to enhance thermal conductivity in polymer composites more so than conventional ceramic fillers. However, to see a significant increase in thermal conductivity a high loading level of the advanced ceramic is often needed which can have an adverse effect on the mechanical behavior of the composite part. Applications for thermal management using thermal interface materials (TIM) continue to grow with thermoplastic injection molded parts emerging as an area for market growth.

Extending the use of metal surface finishes as intermediate layers in complex composites is often met with difficulty in achieving the proper balance of properties or sufficient adhesion. In the case of chromium metal, in particular chromium electroplating, such issues are known from the automotive industry. Despite this, use of electroplating and other methods of metal deposition are expanding into other high technology areas such as additive manufacturing and microelectromechanical system fabrication (MEMS).

Crosslinked epoxy resins have become popular materials in advanced engineering applications such as the aerospace, packaging, coatings, electrical, and adhesive industries. These resins offer a high strength to weight ratio, but have a drawback of being inherently brittle and exhibit poor flaw tolerance. In microelectronic packaging applications, the thermal expansion coefficients (CTEs) of neat epoxy resins are too high. The addition of inorganic fillers is a traditional solution for increasing fracture toughness and lowering CTE.

Rheology modifiers play an important role in formulating personal care products by providing rheology to the components it is added to. Most skin care formulations are oil in water systems which require rheology modifiers that are hydrophilic in nature such as polymeric rheology modifiers. Some of the polymeric rheology modifiers provide rheology through associations whereas others impart thickening efficiency through hydrodynamic volume increase.