41,564 research outputs found

    Coulomb gauge confinement in the heavy quark limit

    Full text link
    The relationship between the nonperturbative Green's functions of Yang-Mills theory and the confinement potential is investigated. By rewriting the generating functional of quantum chromodynamics in terms of a heavy quark mass expansion in Coulomb gauge, restricting to leading order in this expansion and considering only the two-point functions of the Yang-Mills sector, the rainbow-ladder approximation to the gap and Bethe-Salpeter equations is shown to be exact in this case and an analytic, nonperturbative solution is presented. It is found that there is a direct connection between the string tension and the temporal gluon propagator. Further, it is shown that for the 4-point quark correlation functions, only confined bound states of color-singlet quark-antiquark (meson) and quark-quark (baryon) pairs exist.Comment: 22 pages, 6 figure

    The Effects of Blowing Over Various Trailing-edge Flaps on an NACA 0006 Airfoil Section, Comparisons with Various Types of Flaps on other Airfoil Sections, and an Analysis of Flow and Power Relationships for Blowing Systems

    Get PDF
    The results are presented of a two-dimensional investigation conducted to determine the effect of blowing over various types of trailing-edge flaps on a wing having the NACA 0006 airfoil section and a drooped-nose flap. The position and profile of the trailing-edge flap, the nozzle height, and the location of the flap with respect to the nozzle were found to be important variables. Data from many investigations were used to make an evaluation of the effects of blowing on lift. An analysis was made of flow and power relationships for blowing systems

    Effect of Reynolds number on stability characteristics of a cruciform wing-body

    Get PDF
    An experimental investigation was conducted to determine the effect of Reynolds number on the stability characteristics of a body with cruciform wings at large angles of attack. Pressure distributions and force and moment data (axial force not measured) are presented for Mach 1.60 and 2.70, Reynolds numbers based on body diameter from approximately 130,000 to 2,800,000, and angles of attack from 0 deg to 50 deg. In general, the data show only small effects of Reynolds number throughout the range of test condition. Also discussed are force balance and pressure data that suggest a direct relationship between wind choking and the onset of a nonlinear stability variaton with angle of attack

    Baker Street Wonderpass: evaluation of improvement works

    Get PDF
    Summary: Baker Street Quarter Partnership identified the pedestrian subway under the Marylebone Road as an area that many of its members would like to see improved. Researchers from the Policy Studies Institute were commissioned to provide an impartial evaluation of improvement works that were carried out to transform the subway into the ‘Baker Street Wonderpass’. The views of users were assessed through an online survey of Baker Street Quarter members (June 2015), pedestrian counting and face-to-face surveys both before the improvement works (July 2015) and after the Wonderpass had opened (February 2016). The pre-works surveys took place in July 2015, with 206 subway users’ answering a total of 12 questions. The post-works surveys took place in February 2016 with 163 subway users answering a total of 15 questions. The survey was supplemented by ‘vox-pop’ interviews. Pedestrian counts before and after the improvement works show a very large increase in pedestrian traffic after the improvement works were completed. After the improvement works, morning usage increased by 153.8%, afternoon usage increasing by 27.8%, and evening usage increasing by 70.8%. Survey results showed a substantial improvement in user’s satisfaction with the lighting, cleanliness, overall appearance, safety, signage and visibility of the subway. The redevelopment of the subway and the opening of the Wonderpass have been a clear success. 83.9% of users said that the subway was ‘much better’, and 98.4% of users said that they thought the subway was ‘better’ or ‘much better’ after the improvement works. Overall, the investment in the Marylebone Road underpass has greatly improved usage levels and user perceptions of the subway and some users stated that they used the subway solely to see the renovations and new displays. While users previously complained about the cleanliness, lighting and appearance of the subway, by February 2016 it has been successfully transformed into a much safer, cleaner, and more desirable ‘Wonderpass’ to cross Marylebon

    Freezing line of the Lennard-Jones fluid: a Phase Switch Monte Carlo study

    Full text link
    We report a Phase Switch Monte Carlo (PSMC) method study of the freezing line of the Lennard-Jones (LJ) fluid. Our work generalizes to soft potentials the original application of the method to hard sphere freezing, and builds on a previous PSMC study of the LJ system by Errington (J. Chem. Phys. {\bf 120}, 3130 (2004)). The latter work is extended by tracing a large section of the Lennard-Jones freezing curve, the results for which we compare to a previous Gibbs-Duhem integration study. Additionally we provide new background regarding the statistical mechanical basis of the PSMC method and extensive implementation details.Comment: 18 pages, 6 figure

    Survey of J=0,1 mesons in a Bethe-Salpeter approach

    Full text link
    The Bethe-Salpeter equation is used to comprehensively study mesons with J=0,1 and equal-mass constituents for quark masses from the chiral limit to the b-quark mass. The survey contains masses of the ground states in all corresponding J^{PC} channels including those with "exotic" quantum numbers. The emphasis is put on each particular state's sensitivity to the low- and intermediate-momentum, i.e., long-range part of the strong interaction.Comment: 8 pages, 4 figure

    Counseling College Student-Athletes: A Working Alliance Model Approach

    Get PDF
    Student-athletes often represent a highly visible, yet decidedly misunderstood population on college and university campuses. In the general student population, the combination of multiple stressors often leads students to seek professional counseling services. Unfortunately, student-athletes, who are often faced with a multitude of psychosocial stressors germane to balancing athletic and academic responsibilities, seldom seek out professional counseling services. However, when they do seek services, the authors posited that an understanding of the construct of the therapeutic working alliance and the application of the working alliance model (Bordin, 1979) offered a useful template for fostering positive counseling outcomes with student-athletes. In this article, the major elements of this construct and model were presented along with a discussion and implications for its application to a college or university student-athlete population
    • …
    corecore