A direct and inverse boundary layer method for subsonic flow over delta wings

A new inverse boundary layer method is developed and applied to incompressible flows with laminar separation and reattachment. Test cases for two dimensional flows are computed and the results are compared with those of other inverse methods. One advantage of the present method is that the calculation of the inviscid velocities may be determined at each marching step without having to iterate. The inverse method was incorporated with the direct method to calculate the incompressible, conical flow over a slender delta wing at incidence. The location of the secondary separation line on the leeward surface of the wing is determined and compared with experiment for a unit aspect ratio wing at 20.5 deg incidence. The viscous flow in the separated region was calculated using prescribed skin friction coefficients

Method and apparatus for improving performance of AC machines

A method and apparatus for improving the performance of polyphase AC machines. The polyphase AC machines are excited both with a fundamental frequency and with an odd harmonic of the fundamental frequency. The fundamental flux wave and the harmonic flux wave will travel at synchronous speed in the air gap. This facilitates redistributing the flux densities in the machine and thereby increasing the total flux per pole in the machine.Board of Regents, University of Texas Syste

Calculation of acid dissociation constants

A computational method has been developed for the determination of dissociation constants of acids (and bases). The method is applicable to mono or polybasic acids and, in certain cases, to mixtures of acids. A least-squares treatment is employed, and no simplifying assumptions are made in any of the equations or factors involved. All the available data are utilized, and provision is made for including or calculating activity coefficients. Utilization of the method requires a medium to large size digital computer

Motivation, achievement orientation, and competition in collegiate track and field athletes

Competition and motivation are important components of sports. Based on Self-Determination Theory and Cognitive Evaluation Theory (Deci &Ryan, 1985), this study had four purposes. The purposes of the current study were to: a) evaluating gender differences in preferences toward internal or external competition b) examining the relationship of competition preferences and sport achievement orientations with motivation type c) investigating the motivational profiles of athletes based on their competition preference towards internal and external competition and d) exploring gender differences in motivation and sport achievement orientations. Participants (N=142) were NCAA Division-I collegiate track and field athletes from various universities throughout the United States. The participants completed a measures assessing a demographic, a motivation type (Behavioral Regulation in Sport Questionnaire; BRSQ), sport achievement orientation (Sport Orientation Questionnaire; SOQ) and competition preference (Internal and External Competition Questionnaire; IECQ). Paired- samples t-tests, Pearson correlation and various ANOVAs were conducted to analyze the data. Results of the study indicated that a) both male and female track and field athletes have a higher preference for external competition than internal competition b) internal and external competition preference and sport achievement orientation variables were positively related to one or more self- determined motivational variables (intrinsic, integrated or identified motivation), c) three distinct competition preference groups were identified and there are motivational differences between the groups d) women had higher levels of self-determined forms of motivation than males, but no significant differences were found in sport achievement orientation. The results are discussed in relative to the Self-Determination Theory and Cognitive Evaluation Theory (Deci & Ryan, 1985).  M.S

Nearshore internal bores and turbulent mixing in southern Monterey Bay

We observed transient stratification and mixing events associated with nearshore internal bores in southern Monterey Bay using an array of instruments with high spatial and temporal resolution. The arrival of the bores is characterized by surging masses of dense (cold) water that tend to stratify the water column. The bore is followed by a gradual drop in the temperature throughout the water column over several hours (defined here as the bore period) until a sharp warm-front relaxation, followed by high frequency temperature fluctuations, returns the column back to nearly its original state (defined here as the mixing period). Mixing periods revealed increased temperature variance at high frequencies (ω \u3e ), as well as a greater percentage of events where dynamic instabilities may be present (Ri\u3c 0.25), suggesting active mixing of the stratified water column. Turbulent dissipation rates in the stratified interior during the mixing period, estimated using the technique of isopycnal slope spectra, revealed mean values the same order of magnitude as near-bed bottom-generated turbulence. Observations indicate that local shear-produced turbulent kinetic energy by the warm front relaxations dominates mixing in the stratified interior. The non-canonical nature of these bore and relaxation events is also investigated with a numerical model, and the dynamics are shown to depend on the internal Iribarren number. Our results suggest that nearshore internal bores interacting with local bathymetry dramatically alter local dynamics and mixing in the nearshore with important ecological implications

Democratically engaged assessment: Reimagining the purposes and practices of assessment in community engagement

This document is a project of reclamation and transformation, one that is both ongoing and rooted in years of dialogue within Imagining America and the work of its Assessing Practices of Public Scholarship research group (APPS). It emerges from our own experiences with assessment related to community engagement and from those of many other colleagues on campuses and in diverse communities. It is intended to bring together those who wish to reimagine assessment in light of its civic potential — to develop what we refer to as Democratically Engaged Assessment (DEA).Imagining Americ

Echangeur de chaleur “air-terre” pour la climatisation passive de locaux : Etude de cas réalisée au Burkina Faso

An Earth Air Heat Exchanger is a novel way to cool and heat buildings using the ground temperature. Earth Air Heat Exchangers are cheaper and they use less energy than traditional air conditioning. These factors make it a perfect technology to cool houses and buildings in Burkina Faso, a developing country with a major indoor cooling demand. This study shows that in Burkina Faso it is possible to build a simple EAHX to cool down ambient air by 10°C which in turn can cool down a room by 1°C-5°C. The EAHX will be 30 meters long, buried 1.5 meters in the ground and use a ventilator with a flow rate of 90 m3/h. In total the EAHX will cost CFA 300,000 ($US 600)

Integrability of a conducting elastic rod in a magnetic field

We consider the equilibrium equations for a conducting elastic rod placed in a uniform magnetic field, motivated by the problem of electrodynamic space tethers. When expressed in body coordinates the equations are found to sit in a hierarchy of non-canonical Hamiltonian systems involving an increasing number of vector fields. These systems, which include the classical Euler and Kirchhoff rods, are shown to be completely integrable in the case of a transversely isotropic rod; they are in fact generated by a Lax pair. For the magnetic rod this gives a physical interpretation to a previously proposed abstract nine-dimensional integrable system. We use the conserved quantities to reduce the equations to a four-dimensional canonical Hamiltonian system, allowing the geometry of the phase space to be investigated through Poincar\'e sections. In the special case where the force in the rod is aligned with the magnetic field the system turns out to be superintegrable, meaning that the phase space breaks down completely into periodic orbits, corresponding to straight twisted rods.Comment: 19 pages, 1 figur

Geostatistical Characterization of the Spatial Distribution of Adult Corn Rootworm (Coleoptera: Chrysomelidae) Emergence

Geostatistical methods were used to characterize spatial variability in western ( Diabrotica virgifera virgifera LeConte) and northern ( Diabrotica barberi Smith & Lawrence) corn rootworm adult emergence patterns. Semivariograms were calculated for adult emergence density of corn rootworm populations in fields of continuous corn and rotated (corn/soybean) corn. Adult emergence densities were generally greater for northern corn rootworms than for western corn rootworms. The spatial structures of the adult rootworm emergence were aggregated as described by spherical spatial models for western corn rootworm and exponential models for northern corn rootworm. Range of spatial dependence varied from 180 to 550 m for western corn rootworm and 172 to 281 m for northern corn rootworm. Semivariograrn models were used to produce contour density maps of adult populations in the fields, based on grid sampling of actual emerging adult populations