783 research outputs found

    Dynamics of shape fluctuations of quasi-spherical vesicles revisited

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    In this paper, the dynamics of spontaneous shape fluctuations of a single, giant quasi-spherical vesicle formed of a single lipid species is revisited theoretically. A coherent physical theory for the dynamics is developed based on a number of fundamental principles and considerations and a systematic formulation of the theory is also established. From the systematic theoretical formulation, an analytical description of the dynamics of shape fluctuations of quasi-spherical vesicles is derived. In particular, in developing the theory we have made a new interpretation of some of the phenomenological constants in a canonical continuum description of fluid lipid-bilayer membranes and shown the consequences of this new interpretation in terms of the characteristics of the dynamics of vesicle shape fluctuations. Moreover, we have used the systematic formulation of our theory as a framework against which we have discussed the previously existing theories and their discrepancies. Finally, we have made a systematic prediction about the system-dependent characteristics of the relaxation dynamics of shape fluctuations of quasi-spherical vesicles with a view of experimental studies of the phenomenon and also discussed, based on our theory, a recently published experimental work on the topic.Comment: 18 pages, 4 figure

    The oblique impingement of an axisymmetric jet

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    The mechanics of the oblique impingement of an axisymmetric jet on a plane surface are examined in detail. The stagnation point is discussed. A schematic drawing of the problem and coordinate system used to describe the flow field are given. The kinematic features of the flow above the plate are examined in the context of the conservation of mass, the vorticity of the jet, and the vorticity introduced by the jetplate interaction. The dynamic features of the flow are examined in terms of the surface pressure distribution and the cause-effect relationships which exist between the pressure and velocity/vorticity distributions. Flow calculations performed are given. The investigation is relevant to the flow resulting from the interaction of the propulsion jet with the main airfoil (STOL aircraft), and is appropriate to an over- or under- wing configuration

    A study of the round jet/plane wall flow field

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    Impingement angles, between the axisymmetric jet axis and the plane wall, from zero to 15 degrees have been examined for nozzle heights of 0.75, 1.0, 1.5 and 2.0 diameters and for: (1) a fully developed pipe flow, and (2) a relatively uniform exit velocity condition. Velocity measurements have been used to define isotach contours and to determine mass, momentum and energy flux values for the near field (within five diameters) of the jet. Surface pressure measurements have been used to define surface pressure forces and jet centerline trajectories. The geometric and flow conditions examined and the interpretation of the results have been motivated by the externally blown flap STOL aircraft application

    The effect of exit conditions on the development of an axisymmetric turbulent free jet

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    The mean flow in the near field of a submerged axisymmetric jet emitting from a plane wall is presented. An experimental configuration to provide a nearly uniform mean velocity profile with a core of homogeneous turbulence of variable intensity and scale was developed. Eight cases with intensity values of 0.004 less than or equal to U prime less than or equal to 0.035 and integral scales up to l sub x/R = 0.28 were investigated using conditional sampling techniques. It was found that the jet exhibits an increasing momentum flux in the near field. Contrary to expectation and the accepted assumption of ambient static pressure in a turbulent jet, results seem to be conclusive and borne out by comparison with published data. Both integral measures, mass and momentum flux ratios, are insensitive to exit turbulence variations, but, the detailed structure (including centerline velocity) variations with exit conditions are systematic and explainable

    An Analytical Examination on the Effects of Vegetarian and Omnivorous Diets on C-Reactive Protein

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    There is a lack of research regarding how following a vegetarian or omnivores diet effects C-Reactive Protein (CRP) levels of people as seen through results from an analysis of data gathered from the National Health and Nutrition Examination Survey (NHANES). The level of CRP is a reflection of how much inflammation there is in one’s body and is a popular indicator of risk for heart disease. Thus, in this research, I use the NHANES data to look at the relationship of CRP levels of people who identified themselves as vegetarian or not, while also considering the general healthiness of each diet based on their Healthy Eating Index (HEI) score. While there exists a vast prevalence of studies and research into the health benefits of following a restricted meat or vegetarian diet compared to one including meat, there is a rarity of studies that look at how well either diet meets a nationally accepted healthy diet over time and the C-Reactive Protein levels of either group who met and exceeded or fell below the standard of a nationally accepted healthy diet

    Mean flow characteristics for the oblique impingement of an axisymmetric jet

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    The oblique impingement of an axisymmetric jet has been investigated. A summary of the data and the analytical interpretations of the dominant mechanisms which influence the flow are reported. The major characteristics of the shallow angle oblique jet impingement flow field are: (1) minimal dynamic spreading as revealed by the surface pressure field, (2) pronounced kinematic spreading as revealed by the jet flow velocity field, (3) a pronounced upstream shift of the stagnation point from the maximum pressure point, (4) the production of streamwise vorticity by the impingement process

    Quarry

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    A descriptive narration of a project to create a 3-D computer animated film, Quarry, about a gargoyle in a big city and a little girl who comes to have a special bond with him. Includes original proposal, storyboard example, production stills, script, and set design and character

    A Method to include Detector Effects in Estimators sensitive to the Trilinear Gauge Couplings

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    This paper describes the use of weighted Monte Carlo events to accurately approximate integrals of functions of the experimentally measured kinematical vectors and their dependence on physical parameters. This technique is demonstrated in estimating the evolution of cross sections, efficiencies, measured kinematical distributions and mean values as functions of the Trilinear Gauge Couplings.Comment: 20 pages, 10 figures, Late
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