Internal fluid mechanics research on supercomputers for aerospace propulsion systems

The Internal Fluid Mechanics Division of the NASA Lewis Research Center is combining the key elements of computational fluid dynamics, aerothermodynamic experiments, and advanced computational technology to bring internal computational fluid mechanics (ICFM) to a state of practical application for aerospace propulsion systems. The strategies used to achieve this goal are to: (1) pursue an understanding of flow physics, surface heat transfer, and combustion via analysis and fundamental experiments, (2) incorporate improved understanding of these phenomena into verified 3-D CFD codes, and (3) utilize state-of-the-art computational technology to enhance experimental and CFD research. Presented is an overview of the ICFM program in high-speed propulsion, including work in inlets, turbomachinery, and chemical reacting flows. Ongoing efforts to integrate new computer technologies, such as parallel computing and artificial intelligence, into high-speed aeropropulsion research are described

Proposal for Strategic Planning for Solid Waste Management in Lewiston, ME

The city of Lewiston currently has excellent provisions for the disposal of solid waste, making waste disposal for citizens a relatively cheap and efficient process. Solid waste is picked up from residences and then sent to Mid Maine Waste Action Corporation (MMWAC). From there, it is turned into ash and then dumped into the Lewiston landfill. Now over 25 years old, municipal officials are concerned about the long term viability of these current arrangements. After being introduced to the current situation by municipal officials and local politicians, the goals of our project were three-fold: 1. Understand the history of waste management in Lewiston and overall patterns of behavior when dealing with waste 2. Understand how other cities with similar characteristics to Lewiston have implemented successful education programs 3. Create a list of suggestions or programs that address the identified complexities within the municipal solid waste system By focusing on these goals, we conducted relevant research that looked at various points of intervention within the system that would have the potential impact of reducing the amount of overall waste being sent to MMWAC and into the landfill. We talked to relevant public officials and professionals to gather the necessary information about the Lewiston waste system. The combined perspectives and knowledge from each of these informants coincided with our own research has guided us towards a number of potential solutions for improving waste practices in Lewiston. We have concluded that creating an education program in schools is the best place to start in the short term in order to begin changing waste management practices at a basic level. To this extent, we selected two primary schools in Lewiston, Geiger and McMahon, to implement programs and curriculum additions that would foster greater environmental awareness and more sustainable waste management practices. In the long term, we feel that implementing a waste reduction program based on economic incentives, such as variable rate pricing, is the best way to increase recycling habits among Lewiston residents. By proposing one short term and long term program, we aim to not only attempt to change the education system as a short term goal, but then offer a broader program that addresses the city of Lewiston as a whole. The programs in schools begin to address recycling behaviors so that when a situation emerges that does call for the implementation of incentive based recycling, Lewiston city residents will be better informed about the program’s benefits

Tax Incidence in Differentiated Product Oligopoly

We analyze the incidence of ad valorem and unit excise taxes in an oligopolistic industry with differentiated products and price-setting (Bertrand) firms. Both taxes may be passed on to consumers by more than 100 percent, and an increase in the tax rate can increase short run firm profits (and hence the long run number of firms). We provide summary conditions for these effects to arise. The conditions depend on demand curvatures and are written in elasticity form. Surprisingly, the analysis largely corroborates Cournot results with homogeneous demand.Excise tax, unit tax, specific tax, ad valorem tax, imperfect competition, product differentiation, Bertrand, oligopoly, tax incidence, discrete choice models

The Efficiency of Indirect Taxes under Imperfect Competition

This paper considers the relative efficiency of ad valorem and unit taxes in imperfectly competitive markets. We provide a simple proof that ad valorem taxes are welfare-superior to unit taxes in the short run when production costs are identical across firms. The proof covers differentiated products and a wide range of market conduct. Cost asymmetries strengthen the case for ad valorem taxation under Cournot competition, but unit taxation may be welfare-superior under Bertrand competition with product differentiation. Ad valorem taxation is superior with free entry under Cournot competition, but not necessarily under price competition when consumers value variety.Excise tax, unit tax, specific tax, ad valorem tax, tax efficiency, product differentiation, imperfect competition

Core Strength Testing: Developing Normative Data for Three Clinical Tests

BACKGROUND AND PURPOSE: The importance of core stability in activities of daily living, athletic performance, and in preventing low back pain (LBP) and extremity injuries is becoming increasingly accepted and better understood in modern literature. However, normative values for current core endurance tests have yet to be validated for clinic use. The purpose of this research project was to determine core endurance strength normative values for three core endurance tests in healthy men and women between the ages of 18 and 55 years old. METHODS: One-hundred-sixteen subjects (76 female and 40 male) with a mean age of 28.8 years participated in this study over a two-year period. Subjects completed a general health and exercise history questionnaire. Each subject was randomly assigned a test order and was tested by one of nine student researchers. The core endurance tests performed were the 60 degree flexion test (Fl), trunk extensor endurance test (Ext), right side plank (RSP), and left side plank (LSP). Analysis included a one-way ANOVA and multiple regression to determine differences between groups and to understand what variables influenced test outcomes. RESULTS: Normative mean values in seconds for each test are: Fl 160(102); Ext 101(51); RSP 54(25); LSP 55(28). One-way ANOVA revealed the following significant differences: gender M/F (RSP p=.00, LSP p=.00), exercise Y/N (RSP p=.03, LSP p=.01, Fl p=.000), active runners Y/N (RSP p=.001, LSP p=.005, Fl p=.001), strength training Y/N (RSP p=.001, LSP p=.000), core exercise Y/N (LSP p=.01), competitive athletes Y/N (RSP p=.01, LSP p=.02, Fl p=.04). Total time of all four tests noted significant differences for exercise Y/N (p=.005) and run Y/N (p=.003), but revealed no significant difference between gender. Multiple regression models revealed that exercise and core time were significant predictors of LSP. Exercise time was a significant predictor of Fl test, and age and waist circumference were significant predictors for Ext test. The overall model for RSP displayed a trend toward significance. CONCLUSION: Our results suggest that normative values can be established for the Fl and Ext tests regardless of gender, however RSP and LSP tests were significant for differences between genders. The results also suggest that increased activity level improved core endurance

Prototype of a Smithfield Nutrient Cover

Smithfield Hog Production has processing facilities throughout the state of Iowa as well as contract finishing sites where producers grow out their swine. The hog manure from these sites is pumped into a slurry store for storage until it can be pumped onto the fields in the spring or fall. The slurry stores stand 19-feet-tall, have a diameter of 120-feet, and hold 1.2-million-gallons of manure. The slurry stores have no cover so they are open to all weather like rain and snow. Most years, evaporation does not equal precipitation which results in a decreased manure holding capacity and an increased cost to pump the manure. The precipitation that accumulates in the tank also lowers the per gallon value of the nutrients as a crop fertilizer due to dilution. A cover for the slurry tanks would eliminate precipitation from entering the tank