The Materials Advantage of the SLS Selective Laser Sintering Process

The rapid prototyping market continues to progress in tenns of processes and materials used for the creation of conceptual and functional parts and prototype tooling. As this market continues to mature, the market leaders win be able to offer rapid prototyping processes and materials that provide parts which are accurate, have good surface finish, and provide properties which support fqnctional applications.. The materials used for these parts will be. polymers, metals, and ceramics. '. The strength oithe SLSTM Selective Laser Sintering Process is the. potential to use a wide variety of powdered materials for the creation of models, patterns, and some fonns of prototype tooling. ,This paper will cover the types of materials currently used in the SLS process and their inherent advantages.and discuss current research into the development of new materials.Mechanical Engineerin

A comparison of the antimicrobial efficacy of silver diamine fluoride and silver nitrate: an in vitro study

A COMPARISON OF THE ANTIMICROBIAL EFFICACY OF SILVER DIAMINE FLUORIDE AND SILVER NITRATE: AN IN VITRO STUDY By: Nicholas L Luke, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, May 2018 Thesis Advisor: William O. Dahlke Jr., D.M.D. Pediatric Dentistry, Department Chair Purpose: To determine the antimicrobial efficacy of SDF and SN/NaF. Methods: Three bacterial species were combined to create an in vitro biofilm. Treatment was completed with SN, SN/NaF, SDF, SDF½ or untreated (control). Results: The untreated group demonstrated significantly higher growth than all other treatment groups across the study. On the BHI-plates (1-day), there were significant differences between all treatments except SDF and SDF½. On the BHI-plates (3-days), SN/NaF was not significantly different from SDF or SDF½. On the L-MRS-plates (1-day), both SN treatment groups yielded significantly higher growth than the SDF groups. On the L-MRS-plates (3-days), SN yielded significantly higher growth than SN/NaF, SDF, and SDF½. Conclusion: SDF is more effective than SN/NaF, with the exception of BHI-plates (3-days) only and SN/NaF is more effective than SN on primarily S. mutans and L. acidophilus. There is evidence of a possible antimicrobial tolerance of oral bacteria to silver

Rational approximations to the solution of the second order Ricatti equation Technical report, 15 Jan. - 14 Oct. 1965

Rational approximations to solution of second order nonlinear Ricatti equation, using linear transformations - differential equations and operational calculu

Generalized rational approximations with applications to problems in control theory Interim technical report

Rational approximations and solution of control theory problems involving Ricatti equation

Analysis of the coupled frequencies and mode shapes of vehicle control systems Final report, 15 Apr. 1965 - 14 Apr. 1966

Coupled frequencies and mode shapes of vehicle control syste

Rational approximations to the generalized Duffing equation Final report, 15 Jan. - 1965 - 14 Jan. 1966

Linear transformation to obtain rational approximation to response of physical system described by nonlinear differential equation including Duffing equation as special cas

The Visible Hand: Race and Online Market Outcomes

We examine the effect of race on market outcomes by selling iPods through local online classified advertisements throughout the United States in a year-long field experiment. Each ad features a photograph of the product being held by a dark- or light-skinned (“black” or “white”) hand. To provide context, we also consider a group of sellers against whom buyers might statistically discriminate for similar reasons: white sellers with wrist tattoos. Black sellers do worse than white sellers on a variety of market outcome measures: They receive 13% fewer responses and 17% fewer offers. These effects are strongest in the Northeast, and are similar in magnitude to those associated with the display of a wrist tattoo. Conditional on receiving at least one offer, black sellers also receive 2–4% lower offers, despite the selfselected—and presumably less biased—pool of buyers. In addition, buyers corresponding with black sellers exhibit lower trust: They are 17% less likely to include their name in e-mails, 44% less likely to accept delivery by mail, and 56% more likely to express concern about making a long-distance payment. We find evidence that black sellers suffer particularly poor outcomes in thin markets; it appears that discrimination may not “survive” in the presence of significant competition among buyers. Furthermore, black sellers do worst in the most racially isolated markets and markets with high property crime rates, consistent with channels through which we might expect statistical discrimination to operate.race, advertising

Numerical integration of nonlinear differential equations by use of rational approximation Final report, 15 Jan. 1965 - 14 Jul. 1967

Numerical integration of nonlinear differential equations by use of rational approximatio