Master\u27s Project: Tending to Joy

If we dare to hope for the thriving of humans and all of life, then joy must hold a solid place in our imagination. The purpose of this project was to breathe joy into my own life and into the world around me. Following a literature review, I carried out three mini-projects – creating crowd-sourced collages out of what brings people joy, sending daily text messages with quotes about joy, and providing cookies to groups working on social change efforts. The projects succeeded in spreading delight, raising spirits, and inspiring reflection. The journey towards cultivating joy in my own life was substantially messier and remains completely unresolved. I conclude this project not yet able but still aspiring to fully say “yes” to life

Product Focused Freeform Fabrication Education

Presented in this paper is our experience of teaching freeform fabrication to students at the Missouri University of Science and Technology, and to high school students and teachers. The emphasis of the curriculum is exposing students to rapid product development technologies with the goal of creating awareness to emerging career opportunities in CAD/CAM. Starting from solid modeling, principles of freeform fabrication, to applications of rapid prototyping and manufacturing in industry sponsored product development projects, students can learn in-depth freeform fabrication technologies. Interactive course content with hands-on experience for product development is the key towards the success of the program.Mechanical Engineerin

Laboratory studies of sticking coefficients and heterogeneous reactions important in the stratosphere

The discovery of ozone depletion during spring in the Antarctic stratosphere has received wide spread attention. Both meteorological and chemical mechanisms have been used in attempts to explain this observation. The chemical theory focused on the chlorofluoromethanes released into the atmosphere. However, gas-phase, homogeneous reactions alone in the model can not adequately explain such a depletion. Heterogeneous reactions on ice surfaces could be important in the Antarctic stratosphere. These reactions are thought to convert ClONO2 and N2O5 into HNO3 in the solid phase while Cl2, HOCl, and ClNO2 are released into the stratosphere as gas-phase products. The photolysis of Cl2, HOCl, and ClNO2, then produces active chlorine which subsequently removes ozone through several catalytic cycles, including the Cl2O2 mechanism. The polar stratospheric clouds are thought to consist of mixtures of water ice, nitric acid, and sulfuric acid. Condensation of HCl onto the PSC's could provide active surfaces for heterogeneous reactions

Study of Ceramic Slurries for Investment Casting with Ice Patterns

Ice patterns generated by rapid freeze prototyping or a molding process can be used to make ceramic investment molds for metal castings. Due to the use of ice, the ceramic slurries must be poured around the pattern and cured at sub-freezing temperatures. Success of this process depends greatly on the mold strength after the gelation of the slurries. This paper describes the experimental results of the mold strength after the gelation of the slurries under different compositions. The parameters considered include mixing time, alumino-silicate vs. fused silica ratio, volume of binder, and volume of catalyst. The strength of the gelled slurries is examined by breaking test bars on a four-point bending apparatus. Weibull modulus for each trial is calculated based on the breaking strength from four-point bend tests. Analysis of variance for breaking strength and Weibull analysis is performed to evaluate the significance of the effect of each parameter. The casting of a bolt is used to demonstrate that metal castings of complex geometry can be fabricated using investment casting with ice patterns.Mechanical Engineerin

Modeling and Validation of Temperature and Concentration for Rapid Freeze Prototyping

Rapid Freeze Prototyping is a solid freeform fabrication process that uses water as the main build material in a cold environment to create three-dimensional parts. A eutectic sugar-water solution (C6H12O6 – H2O) has been used as a sacrificial material in order to create complex 3D parts with features such as overhangs. A study of the interaction of the build and support materials is presented in this paper. The temperature of both materials during deposition and subsequent cooling is modeled using a semi-empirical model and a theoretical model. A concentration model is used to predict the concentration in the fabricated parts around the interface of the two materials with predicted temperatures as input. Experiments are conducted to validate both the temperature and concentration models.Mechanical Engineerin

Transmitter switch for high-power microwave output

Combiner system can be used for combining output powers of two transmitters or for switching from one to the other. This can be done when pair of transmitters operate on same frequency and carriers are phase coherent as by excitation from single exciter

Shell Cracking In Investment Casting with Laser Stereolithography Patterns

This paper presents an investigation of ceramic shell cracking during the burnout process in investment casting with internally webbed laser stereolithography patterns. We hypothesize that shell cracking will occur when the rupture temperature of the ceramic shell is lower than both the glass transition temperature of the pattern material and the web· link buckling temperature. The hypothesis is validated by our experimental observations which confirm the numerical predictions from our fillite element analysis. This provides a basis for design of the internal web geometry of a lithography pa.tternand evaluation ofthe burnolltprocesswithsuch a pattern. We show the shell cracking and web link buckling temperatures to be functiollsofthe pattern geometry (including the cross~sectional dimensions and span length of the web link) and the shell thickness.Mechanical Engineerin

Study on Incorporating Support Material in Rapid Freeze Prototyping

Rapid Freeze Prototyping (RFP) is a rapid prototyping method that uses water freezing into ice to make three-dimensional parts. Each layer of a geometry is deposited and allowed to freeze before the next layer is added. Using a support material in RFP is a relatively new addition to the process. Validating the successful use of a support material in conjunction with the main build material of water is presented in this paper. The support material selected for use is a eutectic sugar solution. The selection criteria, properties, and characteristics of the support material are discussed. Of particular interest is the diffusion between the support and main build material, which must be minimized to an acceptable level for producing good quality, reproducible, complex parts.Mechanical Engineerin