2,582 research outputs found
The Gribov Ambiguity for Maximal Abelian and Center Gauges in SU(2) Lattice Gauge Theory
We present results for the fundamental string tension in SU(2) lattice gauge
theory after projection to maximal abelian and direct maximal center gauges. We
generate 20 Gribov copies/configuration. Abelian and center projected string
tensions slowly decrease as higher values of the gauge functionals are reached.Comment: 3 pages, latex, 1 postscript figure, presented at Lattice
2000(Topology and Vacuum
GEMPAK: An arbitrary aircraft geometry generator
A computer program, GEMPAK, has been developed to aid in the generation of detailed configuration geometry. The program was written to allow the user as much flexibility as possible in his choices of configurations and the detail of description desired and at the same time keep input requirements and program turnaround and cost to a minimum. The program consists of routines that generate fuselage and planar-surface (winglike) geometry and a routine that will determine the true intersection of all components with the fuselage. This paper describes the methods by which the various geometries are generated and provides input description with sample input and output. Also included are descriptions of the primary program variables and functions performed by the various routines. The FORTRAN program GEMPAK has been used extensively in conjunction with interfaces to several aerodynamic and plotting computer programs and has proven to be an effective aid in the preliminary design phase of aircraft configurations
The Maximal Abelian Gauge, Monopoles, and Vortices in SU(3) Lattice Gauge Theory
We report on calculations of the heavy quark potential in SU(3) lattice gauge
theory. Full SU(3) results are compared to three cases which involve
gauge-fixing and projection. All of these start from the maximal abelian gauge
(MAG), in its simplest form. The first case is abelian projection to U(1)xU(1).
The second keeps only the abelian fields of monopoles in the MAG. The third
involves an additional gauge-fixing to the indirect maximal center gauge
(IMCG), followed by center projection to Z(3). At one gauge
fixing/configuration, the string tensions calculated from MAG U(1)xU(1), MAG
monopoles, and IMCG Z(3) are all less than the full SU(3) string tension. The
projected string tensions further decrease, by approximately 10%, when account
is taken of gauge ambiguities. Comparison is made with corresponding results
for SU(2). It is emphasized that the formulation of the MAG is more subtle for
SU(3) than for SU(2), and that the low string tensions may be caused by the
simple MAG form used. A generalized MAG for SU(3) is formulated.Comment: 22 pages, latex, 2 postscript figures. Replaced version has added
data at beta=6.0, analysis of Gribov ambiguities, extended tables of results,
discussion of scalin
Design and experimental evaluation of a swept supercritical Laminar Flow Control (LFC) airfoil
A large chord swept supercritical laminar flow control (LFC) airfoil was designed, constructed, and tested in the NASA Langley 8-ft Transonic Pressure Tunnel (TPT). The LFC airfoil experiment was established to provide basic information concerning the design and compatibility of high-performance supercritical airfoils with suction boundary layer control achieved through discrete fine slots or porous surface concepts. It was aimed at validating prediction techniques and establishing a technology base for future transport designs and drag reduction. Good agreement was obtained between measured and theoretically designed shockless pressure distributions. Suction laminarization was maintained over an extensive supercritical zone up to high Reynolds numbers before transition gradually moved forward. Full-chord laminar flow was maintained on the upper and lower surfaces at M sub infinity = 0.82 up to R sub c is less than or equal to 12 x 10 to the 6th power. When accounting for both the suction and wake drag, the total drag could be reducted by at least one-half of that for an equivalent turbulent airfoil. Specific objectives for the LFC experiment are given
The NASA Langley laminar-flow-control experiment on a swept, supercritical airfoil: Evaluation of initial perforated configuration
The initial evaluation of a large-chord, swept, supercritical airfoil incorporating an active laminar-flow-control (LFC) suction system with a perforated upper surface is documented in a chronological manner, and the deficiencies in the suction capability of the perforated panels as designed are described. The experiment was conducted in the Langley 8-Foot Transonic Pressure Tunnel. Also included is an evaluation of the influence of the proximity of the tunnel liner to the upper surface of the airfoil pressure distribution
Factors Associated with Diabetes Risk in South Texas College Students
International Journal of Exercise Science 7(2) : 110-118, 2014. South Texas has a high prevalence of diabetes and college students may be particularly at risk. While increased BMI, sedentary activity and depression have been associated with diabetes progression in the general population, it has not been established whether these factors contribute to increased diabetes risk in college students. The purpose of this study was to assess diabetes risk and determine whether depressive symptoms or physical activity patterns are associated with increased diabetes risk in college students. Sixty-nine college students were assessed for diabetes risk using the Finnish Diabetes Risk Score (FINDRISC) . Each participant completed the International Physical Activity Questionnaire (IPAQ) which included a sitting subscale, the Zung Self-Rated Depression Scale, and had anthropometric measures taken. Of the participants, 21.7% reported elevated risk (FINDRISC score 7-11), and 4.3% of participants had a moderate-to-high risk of developing diabetes (FINDRISC \u3e12). On average, the sample was overweight (BMI = 26.81±0.75 kg . m-2), and BMI was associated with diabetes risk (r = 0.626, p \u3c 0.001). While diabetes risk was not correlated with IPAQ total physical activity score (r = 0.019, p = 0.874), it was modestly correlated with time spent sitting (r = 0.295, p = 0.015). There was no association between self-reported depressive symptoms and diabetes risk (r =0.078, p = 0.525). Although diabetes risk was not associated with total activity and depressive symptoms, it was associated with time spent sitting and BMI. These results suggest that in this population, sitting less and reducing weight may help lower the risk of developing diabetes
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