107,248 research outputs found

    Professional Excellence

    Get PDF

    Adaptive high-order finite element solution of transient elastohydrodynamic lubrication problems

    Get PDF
    This article presents a new numerical method to solve transient line contact elastohydrodynamic lubrication (EHL) problems. A high-order discontinuous Galerkin (DG) finite element method is used for the spatial discretization, and the standard Crank-Nicolson method is employed to approximate the time derivative. An h-adaptivity method is used for grid adaptation with the time-stepping, and the penalty method is employed to handle the cavitation condition. The roughness model employed here is a simple indentation, which is located on the upper surface. Numerical results are presented comparing the DG method to standard finite difference (FD) techniques. It is shown that micro-EHL features are captured with far fewer degrees of freedom than when using low-order FD methods

    Information on bird navigation obtained by British long range radars

    Get PDF
    Radar observations of the migratory habits of passerine birds over a 10 year period are presented. The relationships between intensity of cloud cover and the frequency and density of migration are illustrated. The aspects of migration which were determined by the radar were: (1) migration under total overcast, (2) compensation for wind drift, (3) changes in flight direction during migration, and (4) effects of meteorological parameters

    Magentically actuated compressor

    Get PDF
    A vibration free fluid compressor particularly adapted for Stirling cycle cryogenic refrigeration apparatus comprises a pair of identical opposing ferromagnetic pistons located in a housing and between a gas spring including a sealed volume of a working fluid such as gas under pressure. The gas compresses and expands in accordance with movement of the pistons to generate a compression wave which can be vented to other apparatus, for example, a displacer unit in a Stirling cycle engine. The pistons are urged outwardly due to the pressure of the gas; however, a fixed electromagnetic coil assembly located in the housing adjacent the pistons, is periodically energized to produce a magnetic field which interlinks the pistons in such a fashion that the pistons are mutually attracted to one another. The mass of the pistons, in conjunction with the compressed gas between them, form a naturally resonant system which, when the pistons are electromagnetically energized, produces an oscillating compression wave in the entrapped fluid medium

    Autophagy and urothelial carcinoma of the bladder: A review.

    Get PDF
    The incidence of urothelial carcinoma of the urinary bladder (bladder cancer) remains high. While other solid organ malignancies have seen significant improvement in morbidity and mortality, there has been little change in bladder cancer mortality in the past few decades. The mortality is mainly driven by muscle invasive bladder cancer, but the cancer burden remains high even in nonmuscle invasive bladder cancer due to high recurrence rates and risk of progression. While apoptosis deregulation has long been an established pathway for cancer progression, nonapoptotic pathways have gained prominence of late. Recent research in the role of autophagy in other malignancies, including its role in treatment resistance, has led to greater interest in the role of autophagy in bladder cancer. Herein, we summarize the literature regarding the role of autophagy in bladder cancer progression and treatment resistance. We address it by systematically reviewing treatment modalities for nonmuscle invasive and muscle invasive bladder cancer

    Liquid drops on a surface: using density functional theory to calculate the binding potential and drop profiles and comparing with results from mesoscopic modelling

    Get PDF
    The contribution to the free energy for a film of liquid of thickness hh on a solid surface, due to the interactions between the solid-liquid and liquid-gas interfaces is given by the binding potential, g(h)g(h). The precise form of g(h)g(h) determines whether or not the liquid wets the surface. Note that differentiating g(h)g(h) gives the Derjaguin or disjoining pressure. We develop a microscopic density functional theory (DFT) based method for calculating g(h)g(h), allowing us to relate the form of g(h)g(h) to the nature of the molecular interactions in the system. We present results based on using a simple lattice gas model, to demonstrate the procedure. In order to describe the static and dynamic behaviour of non-uniform liquid films and drops on surfaces, a mesoscopic free energy based on g(h)g(h) is often used. We calculate such equilibrium film height profiles and also directly calculate using DFT the corresponding density profiles for liquid drops on surfaces. Comparing quantities such as the contact angle and also the shape of the drops, we find good agreement between the two methods. We also study in detail the effect on g(h)g(h) of truncating the range of the dispersion forces, both those between the fluid molecules and those between the fluid and wall. We find that truncating can have a significant effect on g(h)g(h) and the associated wetting behaviour of the fluid.Comment: 16 pages, 13 fig

    Computation of group table alphanumeric display

    Get PDF
    Computer program, using only group elements as input data, provides machine computation of group tables used for proving theorems and algorithms of finite groups. Program is written for second generation computers

    Device for tensioning test specimens within an hermetically sealed chamber

    Get PDF
    The device is characterized by a support column adapted to be received within an insulated, hermetically sealable chamber. A plurality of anchor pins are mounted on the column for releasibly connecting thereto a plurality of test specimens. A plurality of axially displaceable pull rods are received by the column in coaxial alignment with the anchor pins. One end of each pull rod is provided with a coupling for connecting the pull rod to a test specimen. The opposite end of the pull rod is entended through a cover plate and adapted to be connected with a remotely related linear actuator through a connecting link including a load cell for measuring stress as the pull rod is placed in tension by the actuator
    corecore