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Sample records for radial cool molecular

  1. Radial molecular abundances and gas cooling in starless cores

    CERN Document Server

    Sipilä, O

    2012-01-01

    Aims: We aim to simulate radial profiles of molecular abundances and the gas temperature in cold and heavily shielded starless cores by combining chemical and radiative transfer models. Methods: A determination of the dust temperature in a modified Bonnor-Ebert sphere is used to calculate initial radial molecular abundance profiles. The abundances of selected cooling molecules corresponding to two different core ages are then extracted to determine the gas temperature at two time steps. The calculation is repeated in an iterative process yielding molecular abundances consistent with the gas temperature. Line emission profiles for selected substances are calculated using simulated abundance profiles. Results: The gas temperature is a function of time; the gas heats up as the core gets older because the cooling molecules are depleted onto grain surfaces. The contributions of the various cooling molecules to the total cooling power change with time. Radial chemical abundance profiles are non-trivial: different s...

  2. Laser Cooling of Molecular Anions

    CERN Document Server

    Yzombard, Pauline; Gerber, Sebastian; Doser, Michael; Comparat, Daniel

    2015-01-01

    We propose a scheme for laser cooling of negatively charged molecules. We briefly summarise the requirements for such laser cooling and we identify a number of potential candidates. A detailed computation study with C$\\_2^-$, the most studied molecular anion, is carried out. Simulations of 3D laser cooling in a gas phase show that this molecule could be cooled down to below 1 mK in only a few tens of milliseconds, using standard lasers. Sisyphus cooling, where no photo-detachment process is present, as well as Doppler laser cooling of trapped C$\\_2^-$, are also simulated. This cooling scheme has an impact on the study of cold molecules, molecular anions, charged particle sources and antimatter physics.

  3. Laser cooling of molecular anions.

    Science.gov (United States)

    Yzombard, Pauline; Hamamda, Mehdi; Gerber, Sebastian; Doser, Michael; Comparat, Daniel

    2015-05-29

    We propose a scheme for laser cooling of negatively charged molecules. We briefly summarize the requirements for such laser cooling and we identify a number of potential candidates. A detailed computation study with C_{2}^{-}, the most studied molecular anion, is carried out. Simulations of 3D laser cooling in a gas phase show that this molecule could be cooled down to below 1 mK in only a few tens of milliseconds, using standard lasers. Sisyphus cooling, where no photodetachment process is present, as well as Doppler laser cooling of trapped C_{2}^{-}, are also simulated. This cooling scheme has an impact on the study of cold molecules, molecular anions, charged particle sources, and antimatter physics.

  4. Molecular identity of human outer radial glia during cortical development.

    Science.gov (United States)

    Pollen, Alex A; Nowakowski, Tomasz J; Chen, Jiadong; Retallack, Hanna; Sandoval-Espinosa, Carmen; Nicholas, Cory R; Shuga, Joe; Liu, Siyuan John; Oldham, Michael C; Diaz, Aaron; Lim, Daniel A; Leyrat, Anne A; West, Jay A; Kriegstein, Arnold R

    2015-09-24

    Radial glia, the neural stem cells of the neocortex, are located in two niches: the ventricular zone and outer subventricular zone. Although outer subventricular zone radial glia may generate the majority of human cortical neurons, their molecular features remain elusive. By analyzing gene expression across single cells, we find that outer radial glia preferentially express genes related to extracellular matrix formation, migration, and stemness, including TNC, PTPRZ1, FAM107A, HOPX, and LIFR. Using dynamic imaging, immunostaining, and clonal analysis, we relate these molecular features to distinctive behaviors of outer radial glia, demonstrate the necessity of STAT3 signaling for their cell cycle progression, and establish their extensive proliferative potential. These results suggest that outer radial glia directly support the subventricular niche through local production of growth factors, potentiation of growth factor signals by extracellular matrix proteins, and activation of self-renewal pathways, thereby enabling the developmental and evolutionary expansion of the human neocortex.

  5. The design of an air-cooled metallic high temperature radial turbine

    Science.gov (United States)

    Snyder, Philip H.; Roelke, Richard J.

    1988-01-01

    Recent trends in small advanced gas turbine engines call for higher turbine inlet temperatures. Advances in radial turbine technology have opened the way for a cooled metallic radial turbine capable of withstanding turbine inlet temperatures of 2500 F while meeting the challenge of high efficiency in this small flow size range. In response to this need, a small air-cooled radial turbine has been designed utilizing internal blade coolant passages. The coolant flow passage design is uniquely tailored to simultaneously meet rotor cooling needs and rotor fabrication constraints. The rotor flow-path design seeks to realize improved aerodynamic blade loading characteristics and high efficiency while satisfying rotor life requirements. An up-scaled version of the final engine rotor is currently under fabrication and, after instrumentation, will be tested in the warm turbine test facility at the NASA Lewis Research Center.

  6. Broadband optical cooling of molecular rotors

    CERN Document Server

    Lien, Chien-Yu; Odom, Brian C

    2014-01-01

    Contrary to intuition, resonant laser excitation of bound electrons can decrease the temperature of a system, with electronic relaxation times as fast as nanoseconds allowing for rapid cooling to far below ambient temperature. Although laser cooling of atoms is routine owing to their relatively simple internal structure, laser cooling of molecular translational speeds, vibrations, or rotations is challenging because a different laser frequency is required to electronically excite each populated vibrational and rotational state. Here, we show that molecules with decoupled vibrational and electronic modes can be rotationally cooled using a single spectrally filtered broadband laser to simultaneously address many rotational states. We optically cool AlH$^+$ ions held in a room-temperature radiofrequency Paul trap to collect 96% of the population in the ground quantum state, corresponding to a rotational temperature of 4 K. In our current implementation, parity-preserving electronic cycling cools to the two lowes...

  7. Composite casting/bonding construction of an air-cooled, high temperature radial turbine wheel

    Science.gov (United States)

    Hammer, A. N.; Aigret, G.; Rodgers, C.; Metcalfe, A. G.

    1983-01-01

    A composite casting/bonding technique has been developed for the fabrication of a unique air-cooled, high temperature radial inflow turbine wheel design applicable to auxilliary power units with small rotor diameters and blade entry heights. The 'split blade' manufacturing procedure employed is an alternative to complex internal ceramic coring. Attention is given to both aerothermodynamic and structural design, of which the latter made advantageous use of the exploration of alternative cooling passage configurations through CAD/CAM system software modification.

  8. Broadband Optical Cooling of Molecular Rotors

    Science.gov (United States)

    Lien, Chien-Yu

    Laser cooling of atoms is a widely utilized technique in scientific research, and has been developed over more than three decades. Recently, optically controlling and manipulating the external and internal degrees of freedom of molecules has aroused wide interest in the physics and chemistry communities. However, owing to the more complicated internal structure of molecules, laser cooling of molecules is still underdeveloped. Here we demonstrate cooling the rotation of trapped molecular ions from room temperature to 4 K. The molecule of interest, AlH+, is co-trapped and sympathetically cooled with Ba+ to milliKelvin temperatures in its translational degree of freedom. The nearly diagonal Franck-Condon-Factors between the electronic X and A states of AlH+ create semi-closed cycling transitions between the vibrational ground states of X and A states. A spectrally filtered femtosecond laser is used to optically pump the population to the two lowest rotational levels, with opposite parities, in as little as 100 mus by driving the A-X transition. In addition, a cooling scheme including vibrational relaxation brings the population to the N=0positive-parity level on the order of 100 ms. The population distribution among the rotational levels is detected by resonance-enhanced multiphoton dissociation (REMPD) and time-of-flight mass-spectrometry (TOFMS). This technique opens new avenues to many further studies such as high-precision molecular quantum logic spectroscopy (mQLS) and fundamental constant measurements.

  9. A combined radial collimator and cooled beryllium filter for neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Groitl, Felix, E-mail: felix.groitl@psi.ch [Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland); Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Rantsiou, Emmanouela; Bartkowiak, Marek; Filges, Uwe; Graf, Dieter [Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, 5232 Villigen (Switzerland); Niedermayer, Christof [Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Rüegg, Christian [Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Department of Quantum Matter Physics, University of Geneva, 1211 Geneva (Switzerland); Rønnow, Henrik M. [Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland); Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark)

    2016-05-21

    A flexible, combined, radial collimator and beryllium (Be) filter have been designed and manufactured at the Paul Scherrer Institut (PSI), Switzerland. The Be is integrated in the radial collimator by placing thin Be slices between the collimator lamellas. The filter/collimator is mounted within a vacuum vessel and dry cooled. The flexible design allows for different degrees of collimation and for different Be lengths. Results of measurements carried out at the BOA beamline at PSI are presented. These experiments include rotation scans determining the focal full width half maximum (FWHM), transmission measurements, test of different collimator lamellas and performance tests of the cooling of the filter. This new combined device will be a crucial part of the CAMEA spectrometer at SINQ, PSI.

  10. A combined radial collimator and cooled beryllium filter for neutron scattering

    Science.gov (United States)

    Groitl, Felix; Rantsiou, Emmanouela; Bartkowiak, Marek; Filges, Uwe; Graf, Dieter; Niedermayer, Christof; Rüegg, Christian; Rønnow, Henrik M.

    2016-05-01

    A flexible, combined, radial collimator and beryllium (Be) filter have been designed and manufactured at the Paul Scherrer Institut (PSI), Switzerland. The Be is integrated in the radial collimator by placing thin Be slices between the collimator lamellas. The filter/collimator is mounted within a vacuum vessel and dry cooled. The flexible design allows for different degrees of collimation and for different Be lengths. Results of measurements carried out at the BOA beamline at PSI are presented. These experiments include rotation scans determining the focal full width half maximum (FWHM), transmission measurements, test of different collimator lamellas and performance tests of the cooling of the filter. This new combined device will be a crucial part of the CAMEA spectrometer at SINQ, PSI.

  11. Drag and Cooling with Various Forms of Cowling for a "Whirlwind" Radial Air-Cooled Engine I

    Science.gov (United States)

    Weick, Fred E

    1930-01-01

    This report presents the results of an investigation undertaken in the 20-foot Propeller Research Tunnel at Langley Field on the cowling of radial air-cooled engines. A portion of the investigation has been completed, in which several forms and degrees of cowling were tested on Wright "Whirlwind" J-5 engine mounted in the nose of a cabin fuselage. The cowlings varied from the one extreme of an entirely exposed engine to the other in which the engine was entirely inclosed. Cooling tests were made and each cowling modified, if necessary, until the engine cooled approximately as satisfactorily as when it was entirely exposed. Drag tests were then made with each form of cowling, and the effect of the cowling on the propulsive efficiency determined with a metal propeller. The propulsive efficiency was found to be practically the same with all forms of cowling. The drag of the cabin fuselage with uncowled engine was found to be more than three times as great as the drag of the fuselage with engine removed and nose rounded. The conventional forms of cowling, in which at least the tops of the cylinder heads and valve gear are exposed, reduce the drag somewhat, but the cowling entirely covering the engine reduces it 2.6 times as much as the best conventional one. The decrease in drag due to the use of spinners proved to be almost negligible. The use of the cowling completely covering the engine seems entirely practical as regards both cooling and maintenance under service conditions. It must be carefully designed, however, to cool properly. With cabin fuselages its use should result in a substantial increase in high speed over that obtained with present forms of cowling on engines similar in contour to the J-5. (author)

  12. Radial and temporal variations in surface heat transfer during cryogen spray cooling

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Walfre [Department of Mechanical Engineering, University of California, Riverside, CA 92521 (United States); Liu Jie [Department of Mechanical Engineering, University of California, Riverside, CA 92521 (United States); Wang Guoxiang [Department of Mechanical Engineering, University of Akron, Akron, OH 44325 (United States); Nelson, J Stuart [Beckman Laser Institute, University of California, Irvine, CA 92617 (United States); Aguilar, Guillermo [Department of Mechanical Engineering, University of California, Riverside, CA 92521 (United States)

    2005-01-21

    Cryogen spray cooling (CSC) is a heat extraction process that protects the epidermis from thermal damage during dermatologic laser surgery. The objective of the present work is to investigate radial and temporal variations in the heat transferred through the surface of a skin phantom during CSC. A fast-response thermal sensor is used to measure surface temperatures every 1 mm across a 16 mm diameter of the sprayed surface of the phantom. An analytical expression based on Fourier's law and Duhamel's theorem is used to compute surface heat fluxes from temperature measurements. Results show that radial and temporal variations of the boundary conditions have a strong influence on the homogeneity of heat extraction from the skin phantom. However, there is a subregion of uniform cooling whose size is time dependent. It is also observed that the surface heat flux undergoes a marked dynamic variation, with a maximum heat flux occurring at the centre of the sprayed surface early in the spurt followed by a quick decrease. The study shows that radial and temporal variations of boundary conditions must be taken into account and ideally controlled to guarantee uniform protection during CSC of human skin.

  13. Preliminary Tests of Nose- and Side- Entrance Blower Cooling Systems for Radial Engines, Special Report

    Science.gov (United States)

    Biermann, David; Valentine, E. Floyd

    1939-01-01

    Two cowling systems intended to reduce the drag and improve the low-speed cooling characteristics of conventional radial engine cowlings were tested in model form to determine the practicability of the methods. One cowling included a blower mounted on the rear face of a large propeller spinner which drew cooling air in through side entrance ducts located behind the equivalent engine orifice plate. The air was passed through the equivalent engine orifice plate from rear to front and out through a slot between the spinner and the engine plate. The blower produced substantially all the power necessary to circulate the cooling air in some cases, so the quantity of air flowing was independent of the air speed, Two types of blowers were used, a centrifugal type and one using airfoil blades which forced the air outward from the center of rotation. The other cowling was similar to the conventional N.A.C.A. cowling except for the addition of a large propeller spinner nose. The spinner was provided with a hole in the nose to admit cooling air and blower blades to increase the pressure for cooling at low speeds. The tests show that with both cowling types the basic drag of the nacelle was reduced substantially below that for the N.A.C.A. cowling by virtue of the better nose shape made possible by the spinner . The drag due to the side-entrance ducts was nearly zero when the openings were closed or when the blower was drawing in a certain quantity of air in proportion to the air speed. The drag increased, however, when air mas allowed to spill from the openings. The nose-entrance blower showed considerable promise as a cooling means although the blower tested was relatively inefficient, owing to the fact that the blower compartments evidently were expanded too rapidly under the conditions imposed. by the design.

  14. Structure and radial equilibrium of filamentary molecular clouds

    CERN Document Server

    Contreras, Yanett; Garay, Guido

    2013-01-01

    Recent dust continuum surveys have shown that filamentary structures are ubiquitous along the Galactic plane. While the study of their global properties has gained momentum recently, we are still far from fully understanding their origin and stability. Theories invoking magnetic field have been formulated to help explain the stability of filaments; however, observations are needed to test their predictions. In this paper, we investigate the structure and radial equilibrium of five filamentary molecular clouds with the aim of determining the role that magnetic field may play. To do this, we use continuum and molecular line observations to obtain their physical properties (e.g. mass, temperature and pressure). We find that the filaments have lower lineal masses compared to their lineal virial masses. Their virial parameters and shape of their dust continuum emission suggests that these filaments may be confined by a toroidal dominated magnetic field.

  15. Heat Transfer and Fluid Flow of Nanofluids in Laminar Radial Flow Cooling Systems

    Institute of Scientific and Technical Information of China (English)

    Gilles ROY; Samy Joseph PALM; Cong Tam NGUYEN

    2005-01-01

    Nanofluids are considered as interesting alternatives to conventional coolants. It is well known that traditional fluids have limited heat transfer capabilities when compared to common metals. It is therefore quite conceivable that a small amount of extremely fine metallic particles placed in suspension in traditional fluids will considerably increase their heat transfer performances. A numerical investigation into the heat transfer enhancement capabilities of coolants with suspended metallic nanoparticles inside a radial, laminar flow cooling configuration is presented. Temperature dependant nanofluid properties are evaluated from experimental data available in recent literature. Results indicate that considerable heat transfer increases are possible with the use of relatively small volume fractions of nanoparticles. Generally, however, these are accompanied by considerable increases in wall shear-stress. Results also show that predictions obtained with temperature variable nanofluid properties yield greater heat transfer capabilities and lower wall shear stresses when compared to predictions using constant properties.

  16. Cooling in the Central Molecular Zone

    Science.gov (United States)

    Ragan, Sarah

    2015-10-01

    The Central Molecular Zone (CMZ) of the Milky Way contains a huge reservoir of molecular gas, and yet its star formation efficiency appears to be significantly lower than expected from standard star formation relations. This suggests that additional physics must be considered in order to understand the regulation of star formation in the CMZ. We propose GREAT observations of the [OI] and [CII] transitions toward two compact clouds residing in the so-called 100 pc ring surrounding the Galactic Centre. These lines are predicted to be the primary coolants of molecular clouds in this harsh environment. Measuring the strength of the [CII] and [OI] line emission produced by the clouds will therefore allow us to constrain their total cooling rate, while the [OI]/[CII] line ratio and the ratio of both lines relative to the measured FIR emission will allow us to constrain the density and temperature of the clouds, and hence the intensity of the cosmic ray ionization rate in their vicinity. We can test models that predict that the CMZ is a unique environment in which oxygen dominates carbon as a coolant. The superb velocity resolution provided by GREAT will also allow us for the first time to study the kinematics of the warm gas in the clouds, which we expect to fill much of their volume. Finally, by comparing clouds at different locations within the 100 pc ring, we will be able to study whether the age of the clouds increases as we move away from Sgr A*, allowing us to test the idea that the formation of the clouds may have been triggered by the tidal influence of the Milky Way's central black hole and nuclear star cluster. These ground-breaking observations are only possible with SOFIA and offer several different pathways to high-impact science.

  17. Final design of a 24 MW radially-cooled insert for a 45 T hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Weggel, R.J.; Stejskal, V.; Bobrov, E.; Holowinski, M.; Williams, J.E.C. [M.I.T., Cambridge, MA (United States). Francis Bitter National Magnet Lab.

    1996-07-01

    For the National High Magnetic Field Laboratory the Francis Bitter National Magnet Laboratory has designed and is fabricating a 24 MW radially-cooled insert magnet. It is to add 31 teslas or more to the 14 T of the 616 mm bore superconducting magnet of Hybrid V, a system to generate at least 45 T in a 32 mm bore. The insert embodies many innovations for the sake of housing component commonality, unobstructed access for users, quick installation, efficiency, longevity and burnout isolation, while coping with power densities up to 7 W/mm{sup 3}, heat flux densities to 9 W/mm{sup 2}, water pressures to 40 bars, and fault loads to 3.5 MN. The upper surface of the housing is free of all electrical and hydraulic clutter. The compact coil package plugs in from above. Its three coils are electrically and hydraulically in series-parallel, with inward flow through the outer two coils. High water pressure and short passages give water velocities up to 40 m/s, despite depths of only 0.10 to 0.15 mm, thus achieving outstanding cooling efficiency and a peak temperature of only 68C. Conductors, with strengths to match local stresses, are two thicknesses of copper, three of Be-Cu and two of 24% Ag-Cu. All have excellent combinations of strength and electrical conductivity.

  18. A new type of radially cooled helices designed for a 25 T magnet

    Energy Technology Data Exchange (ETDEWEB)

    Rub, P.; Joss, W. [Centre National de la Recherche Scientifique, Grenoble (France)

    1996-07-01

    The authors designed a new magnet yielding a field of 25 T in a 50 mm room temperature bore for a consumed power of 11.2 MW. It consists of four coils electrically in series and hydraulically in parallel. The two outer coils are Bitter stacks which deliver together 14.7 T in a diameter of 163 mm. Two helices made of CuCrZr alloy with an elastic limit of 360 MPa and an electrical conductivity of 85% IACS constitute the inner part of the magnet. The helices are cut out of cylindrical tubes with an electrical discharge machine and produce a field of 10.4 T in 58 mm. The insulation between turns is obtained by a number of 125 {micro} thick sectors of Kapton, which are maintained by two fiber glass rods. The spaces between the insulators constitute the channels for radial cooling. The high water velocity (about 21 m/s) in the channel results in a relatively low average temperature for the copper. Since July 1994 the magnet has been in operation for several hundred hours and its performance is very encouraging. Presently, it is the only magnet in the facility in which more than 10 MW are dissipated.

  19. Thermo-fluid simulation of a rotating disc with radial cooling passages / Francois Holtzhausen

    OpenAIRE

    Holtzhausen, Francois

    2003-01-01

    Turbine blade cooling via internal cooling channels is a very important aspect in modern-day gas turbine cycles. The need for blade cooling stems from the fact that higher cycle efficiencies requires higher maximum temperatures and therefore also higher turbine inlet temperatures. In order to evaluate the effects of these cooling flows on the cycle as a whole under various load conditions, it is necessary to simulate the compressible flow with heat transfer within the channe...

  20. Rotational Laser Cooling of Vibrationally and Translationally Cold Molecular Ions

    DEFF Research Database (Denmark)

    Drewsen, Michael

    2011-01-01

    by sympathetic cooling with Doppler laser cooled Mg+ ions. Giving the time for the molecules to equilibrate internally to the room temperature blackbody radiation, the vibrational degree of freedom will freeze out, leaving only the rotational degree of freedom to be cooled. We report here on the implementation...... of a new technique for laser-induced rotational ground-state cooling of vibrationally and translationally cold MgH+ ions [10]. The scheme is based on excitation of a single rovibrational transition [11], and it should be generalizable to any diatomic polar molecular ion, given appropriate mid......-infrared laser sources such as a quantum cascade laser are available. In recent experiments, a nearly 15-fold increase in the rotational ground-state population was obtained, with the resulting ground-state population of 36,7±1,2 %, equivalent to that of a thermal distribution at about 20 K. The obtained cooling...

  1. Production and sympathetic cooling of complex molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chaobo

    2008-06-24

    This thesis reports on experimental and theoretical studies of the sympathetic cooling of complex molecular ions demonstrating that this general method for cooling atomic and molecular ions is reliable and efficient. For this purpose, complex molecular ions and barium ions have been confined simultaneously in a linear Paul trap. The complex molecular ions are generated in an electrospray ionization system and transferred to the trap via a 2 m long octopole ion guide. These molecular ions are pre-cooled by room temperature helium buffer gas so that they can be captured by the trap. The atomic barium ions are loaded from a barium evaporator oven and are laser-cooled by a 493 nm cooling laser and a 650 nm repumping laser. Due to the mutual Coulomb interaction among these charged particles, the kinetic energy of the complex molecular ions can be reduced significantly. In our experiments we have demonstrated the sympathetic cooling of various molecules (CO{sub 2}, Alexa Fluor 350, glycyrrhetinic acid, cytochrome c) covering a wide mass range from a few tens to 13000 amu. In every case the molecular ions could be cooled down to millikelvin temperatures. Photo-chemical reactions of the {sup 138}Ba{sup +} ions in the ({sup 2}P{sub 1/2}) excited state with gases such as O{sub 2}, CO{sub 2}, or N{sub 2}O, could be observed. If the initial {sup 138}Ba{sup +} ion ensemble is cold, the produced {sup 138}BaO{sup +} ions are cold as well, with a similar temperature as the laser-cooled barium ions (a few tens of millikelvin). The back-reaction of {sup 138}BaO{sup +} ions with neutral CO to {sup 138}Ba{sup +} is possible and was observed in our experiments as well. A powerful molecular dynamics (MD) simulation program has been developed. With this program dynamic properties of ion ensembles, such as sympathetic interactions or heating effects, have been investigated and experimental results have been analyzed to obtain, for example, ion numbers and temperatures. Additionally, the

  2. Rotational Laser Cooling of Vibrationally and Translationally Cold Molecular Ions

    DEFF Research Database (Denmark)

    Drewsen, Michael

    2011-01-01

    [7,8,9]. Furthermore, in order to learn more about the chemistry in interstellar clouds, astrochemists can benefit greatly from direct measurements on cold reactions in laboratories [9]. Working with MgH+ molecular ions in a linear Paul trap, we routinely cool their translational degree of freedom...... of a new technique for laser-induced rotational ground-state cooling of vibrationally and translationally cold MgH+ ions [10]. The scheme is based on excitation of a single rovibrational transition [11], and it should be generalizable to any diatomic polar molecular ion, given appropriate mid...

  3. Sympathetic cooling of molecular ion motion to the ground state

    CERN Document Server

    Rugango, Rene; Dixon, Thomas H; Gray, John M; Khanyile, Ncamiso; Shu, Gang; Clark, Robert J; Brown, Kenneth R

    2014-01-01

    We demonstrate sympathetic sideband cooling of a $^{40}$CaH$^{+}$ molecular ion co-trapped with a $^{40}$Ca$^{+}$ atomic ion in a linear Paul trap. Both axial modes of the two-ion chain are simultaneously cooled to near the ground state of motion. The center of mass mode is cooled to an average quanta of harmonic motion $\\overline{n}_{\\mathrm{COM}} = 0.13 \\pm 0.03$, corresponding to a temperature of $12.47 \\pm 0.03 ~\\mu$K. The breathing mode is cooled to $\\overline{n}_{\\mathrm{BM}} = 0.05 \\pm 0.02$, corresponding to a temperature of $15.36 \\pm 0.01~\\mu$K.

  4. Rotational laser cooling of vibrationally and translationally cold molecular ions

    DEFF Research Database (Denmark)

    Staanum, Peter; Højbjerre, Klaus; Skyt, Peter Sandegaard

    2010-01-01

    -molecular reactions with coherent light fields 8, 9 , for quantum-state-selected bi-molecular reactions 10, 11, 12 and for astrochemistry 12 . Here, we demonstrate rotational ground-state cooling of vibrationally and translationally cold MgH+ ions, using a laser-cooling scheme based on excitation of a single...... rovibrational transition 13, 14 . A nearly 15-fold increase in the rotational ground-state population of the X  1Σ+ electronic ground-state potential has been obtained. The resulting ground-state population of 36.7±1.2% is equivalent to that of a thermal distribution at about 20 K. The obtained cooling results...

  5. POLYANA-A tool for the calculation of molecular radial distribution functions based on Molecular Dynamics trajectories

    Science.gov (United States)

    Dimitroulis, Christos; Raptis, Theophanes; Raptis, Vasilios

    2015-12-01

    We present an application for the calculation of radial distribution functions for molecular centres of mass, based on trajectories generated by molecular simulation methods (Molecular Dynamics, Monte Carlo). When designing this application, the emphasis was placed on ease of use as well as ease of further development. In its current version, the program can read trajectories generated by the well-known DL_POLY package, but it can be easily extended to handle other formats. It is also very easy to 'hack' the program so it can compute intermolecular radial distribution functions for groups of interaction sites rather than whole molecules.

  6. Intense Atomic and Molecular Beams via Neon Buffer Gas Cooling

    CERN Document Server

    Patterson, David; Doyle, John M

    2008-01-01

    We realize a continuous guided beam of cold deuterated ammonia with a flux of 3e11 ND3 molecules/s and a continuous free-space beam of cold potassium with a flux of 1e16 K atoms/s. A novel feature of the buffer gas source used to produce these beams is cold neon, which, due to intermediate Knudsen number beam dynamics, produces a forward velocity and low-energy tail that is comparable to much colder helium-based sources. We expect this source to be trivially generalizable to a very wide range of atomic and molecular species with significant vapor pressure below 1000 K. This source has properties that make it a good starting point for laser cooling of molecules or atoms, cold collision studies, trapping, or nonlinear optics in buffer-gas-cooled atomic or molecular gases.

  7. Adiabatic Cooling for Rovibrational Spectroscopy of Molecular Ions

    DEFF Research Database (Denmark)

    Fisher, Karin

    2017-01-01

    The field of cold molecular ions is a fast growing one, with applications in high resolution spectroscopy and metrology, the search for time variations of fundamental constants, cold chemistry and collisions, and quantum information processing, to name a few. The study of single molecular ions...... is attractive as it enables one to push the limits of spectroscopic accuracy. Non-destructive spectroscopic detection of molecular ions can be achieved by co-trapping with an easier to detect atomic ion. The ion chain has coupled motion, and transitions which change both the internal and motional states...... to the measured heating rates, almost perfectly fitting existing heating rate theory. Further, the same model successfully predicted the heating rates of the in-phase mode of a two-ion crystal, indicating that we can use it to predict the heating rates in experiments on molecule-atom chains. Adiabatic cooling...

  8. Experimental study of flat plate cooling using draft induced by a submerged radial jet

    Directory of Open Access Journals (Sweden)

    Argemiro Palencia-Diaz

    2017-01-01

    Full Text Available Una investigación experimental se ha llevado a cabo para evaluar la transferencia de calor en una configuración modificada de un chorro radial sumergido, por medio del cual se puede extraer el fluido directamente debajo de la boquilla, en busca de una mejora en la velocidad de transferencia de calor. Los experimentos se llevaron a cabo para las siguientes gamas de parámetros que rigen el fenómeno: boquilla de 16 mm de diámetro, distancia entre boquilla y placa entre 10 mm a 20 mm, número de Reynolds que oscila entre 10.000 y 20.000, y calor de 10,2 – 13,6 kW/m2. La transferencia de calor se estima a través de la distribución de temperatura obtenida por medio de un dispositivo de adquisición de datos y un apropiado post-procesamiento, lo que hace posible determinar el coeficiente de transferencia de calor y el número de Nusselt para las diferentes condiciones en estudio. El uso de la extracción de fluido a través de tiro inducido genera un aumento significativo en la transferencia de calor en el área debajo de la boquilla, obteniendo valores desde 290 hasta 1500 W/m2.°C.

  9. A cryogenic buffer gas cooled beam of BaH for molecular laser cooling and ultracold fragmentation

    Science.gov (United States)

    Iwata, Geoffrey; Tarallo, Marco G.; Soerensen, Fabian; Zelevinsky, Tanya

    2015-05-01

    Laser cooled and trapped molecules promise many possibilities to explore a variety of fields such as many-body physics, quantum collisions and dissociation, and precision measurement. We report on an experiment for cooling and trapping barium monohydride (BaH) diatomic molecules. We present a cryogenic buffer gas cooling apparatus for producing a 4 K beam of BaH, and describe the laser cooling schemes necessary to load a molecular magneto-optical trap from that beam. Current progress includes identification of the cooling transitions in the BaH B2 Σ molecules and construction of the molecular beam. The large mass ratio of constituent atoms in BaH makes this system attractive for future studies of ultracold fragmentation, potentially resulting in samples of ultracold hydrogen atoms.

  10. Conceptual design of a 24--32 MW radially-cooled insert for a {ge}45 T hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Weggel, R.J.; Hake, M.E.; Stejskal, V. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Francis Bitter National Magnet Lab.

    1994-07-01

    The FBNML is designing and will fabricate a radially-cooled insert magnet to generate 70% of the field of a system, Hybrid V, to surpass 45 T in a 32 mm bore. The insert is to have an overall diameter and a maximum active coil length of 610 mm. With a background field of 14 T the system should generate 47 T at 24 MW and nearly 49 T at 32 MW. The peak stress is extremely high, calling for conductors such as Be-Cu (UNS C17510) and 24% Ag-Cu with strengths up to 1,100 MPa. The peak heat flux density also is high, nearly 12 W/mm{sup 2}. Because the water is coldest and its velocity highest where the heat flux is highest, however, the peak temperature is only 80 C. The water flow is {approx} 200 l/s at 27 atm. The system is to be very user friendly. Access is completely unobstructed at the top. Insert removal leaves the plumbing and electrical connections intact. The massive and expensive outer coils should be long lived, the inner coil easily replaceable. During an inner coil burnout, a sleeve intercepts arcing from the inner coil to the middle one, reducing burnout severity and fault loads. The insert should be a worthy successor to those of the FBNML`s world-record holding systems, Hybrids II and III.

  11. Modelling Alkali Line Absorption and Molecular Bands in Cool DAZs

    CERN Document Server

    Homeier, D; Allard, F; Hauschildt, P H; Schweitzer, A; Stancil, P C; Weck, P F; Homeier, Derek; Allard, Nicole F.; Allard, France; Hauschildt, Peter H.; Schweitzer, Andreas; Stancil, Phillip C.; Weck, Philippe F.

    2005-01-01

    Two peculiar stars showing an apparent extremely broadened and strong NaI D absorption have been discovered in surveys for cool white dwarfs by Oppenheimer et al. (2001) and Harris et al. (SDSS, 2003). We discuss the nature of these objects using PHOENIX atmosphere models for metal-poor brown dwarfs/very low mass stars, and new white dwarf LTE and NLTE models for hydrogen- and helium-dominated atmospheres with metals. These include complete molecular formation in chemical equilibrium and a model for the alkali resonance line broadening based on the damping profiles of Allard et al. (2003), as well as new molecular line opacities for metal hydrides. First results of our calculations indicate good agreement with a hydrogen-dominated WD atmosphere with a Na abundance roughly consistent with a state of high accretion. We analyse deviations of the abundances of Na, K, Mg and Ca from the cosmic pattern and comment on implications of these results for standard accretion scenarios.

  12. Molecular orientation sensitive second harmonic microscopy by radially and azimuthally polarized light

    Science.gov (United States)

    Ehmke, Tobias; Nitzsche, Tim Heiko; Knebl, Andreas; Heisterkamp, Alexander

    2014-01-01

    We demonstrate the possibility to switch the z-polarization component of the illumination in the vicinity of the focus of high-NA objective lenses by applying radially and azimuthally polarized incident light. The influence of the field distribution on nonlinear effects was first investigated by the means of simulations. These were performed for high-NA objective lenses commonly used in nonlinear microscopy. Special attention is paid to the influence of the polarization of the incoming field. For linearly, circularly and radially polarized light a considerable polarization component in z-direction is generated by high NA focusing. Azimuthal polarization is an exceptional case: even for strong focusing no z-component arises. Furthermore, the influence of the input polarization on the intensity contributing to the nonlinear signal generation was computed. No distinct difference between comparable input polarization states was found for chosen thresholds of nonlinear signal generation. Differences in signal generation for radially and azimuthally polarized vortex beams were experimentally evaluated in native collagen tissue (porcine cornea). The findings are in good agreement with the theoretical predictions and display the possibility to probe the molecular orientation along the optical axis of samples with known nonlinear properties. The combination of simulations regarding the nonlinear response of materials and experiments with different sample orientations and present or non present z-polarization could help to increase the understanding of nonlinear signal formation in yet unstudied materials. PMID:25071961

  13. Efficient sympathetic motional ground-state cooling of a molecular ion

    CERN Document Server

    Wan, Yong; Wolf, Fabian; Schmidt, Piet O

    2015-01-01

    Cold molecular ions are promising candidates in various fields ranging from precision spectroscopy and test of fundamental physics to ultra-cold chemistry. Control of internal and external degrees of freedom is a prerequisite for many of these applications. Motional ground state cooling represents the starting point for quantum logic-assisted internal state preparation, detection, and spectroscopy protocols. Robust and fast cooling is crucial to maximize the fraction of time available for the actual experiment. We optimize the cooling rate of ground state cooling schemes for single $^{25}\\mathrm{Mg}^{+}$ ions and sympathetic ground state cooling of $^{24}\\mathrm{MgH}^{+}$. In particular, we show that robust cooling is achieved by combining pulsed Raman sideband cooling with continuous quench cooling. Furthermore, we experimentally demonstrate an efficient strategy for ground state cooling outside the Lamb-Dicke regime.

  14. Geometry-Independent Determination of Radial Density Distributions in Molecular Cloud Cores and Other Astronomical Objects

    CERN Document Server

    Krčo, Marko

    2016-01-01

    We present a geometry-independent method for determining the shapes of radial volume density profiles of astronomical objects whose geometries are unknown, based on a single column density map. Such profiles are often critical to understand the physics and chemistry of molecular cloud cores, in which star formation takes place. The method presented here does not assume any geometry for the object being studied, thus removing a significant source of bias. Instead it exploits contour self-similarity in column density maps which appears to be common in data for astronomical objects. Our method may be applied to many types of astronomical objects and observable quantities so long as they satisfy a limited set of conditions which we describe in detail. We derive the method analytically, test it numerically, and illustrate its utility using 2MASS-derived dust extinction in molecular cloud cores. While not having made an extensive comparison of different density profiles, we find that the overall radial density dist...

  15. Vibrational relaxation and vibrational cooling in low temperature molecular crystals

    Science.gov (United States)

    Hill, Jeffrey R.; Chronister, Eric L.; Chang, Ta-Chau; Kim, Hackjin; Postlewaite, Jay C.; Dlott, Dana D.

    1988-01-01

    The processes of vibrational relaxation (VR) and vibrational cooling (VC) are investigated in low temperature crystals of complex molecules, specifically benzene, naphthalene, anthracene, and durene. In the VR process, a vibration is deexcited, while VC consists of many sequential and parallel VR steps which return the crystal to thermal equilibrium. A theoretical model is developed which relates the VR rate to the excess vibrational energy, the molecular structure, and the crystal structure. Specific relations are derived for the vibrational lifetime T1 in each of three regimes of excess vibrational energy. The regimes are the following: Low frequency regime I where VR occurs by emission of two phonons, intermediate frequency regime II where VR occurs by emission of one phonon and one vibration, and high frequency regime III where VR occurs by evolution into a dense bath of vibrational combinations. The VR rate in each regime depends on a particular multiphonon density of states and a few averaged anharmonic coefficients. The appropriate densities of states are calculated from spectroscopic data, and together with available VR data and new infrared and ps Raman data, the values of the anharmonic coefficients are determined for each material. The relationship between these parameters and the material properties is discussed. We then describe VC in a master equation formalism. The transition rate matrix for naphthalene is found using the empirically determined parameters of the above model, and the time dependent redistribution in each mode is calculated.

  16. A simulation of the collapse and fragmentation of cooling molecular clouds

    Science.gov (United States)

    Monaghan, Joe J.; Lattanzio, John C.

    1991-01-01

    The application of the Smoothed Particle Hydrodynamics method to the fragmentation of rotating cloud and disk systems is described, allowing for molecular cooling due to H2 and CO. A novel approach to solving Poisson's equation for disklike structures which exploits the multigrid algorithm is also described. Numerical studies are presented which investigate the evolution of both rotating clouds and Maclaurin disks, in each case with both an isothermal equation of state and with molecular cooling. The results establish the influence of molecular cooling on the fragmentation of molecular clouds. The isothermal sequences, if they fragment at all, do so into far fewer lumps than the cooling sequences. This is not due to a cooling instability as such, but rather to the reduced thermal support. One of the sequences shows a remarkable similarity to the W49A star-forming region.

  17. Structural evolution of Ti50Cu50 on rapid cooling by molecular dynamics simulation

    Science.gov (United States)

    Pang, J. J.; Tan, M. J.; Liew, K. M.

    2012-03-01

    The structural evolution and atomic structure of the Ti50Cu50 compound have been investigated by means of molecular dynamics simulation using the generalized embedded-atom model (GEAM) potential. Gibbs free energy calculation manifests the large driving force of undercooled Ti50Cu50 for crystallization and thus the poor glass-forming ability. Radial distribution functions (RDFs) within the temperature range from 2000 K to 300 K are analyzed and reveal the increasing degree of short-range order and reducing periodic length between peaks on cooling. Atomic arrangement is characterized by the Voronoi tessellation method, showing that the frequency of icosahedral configurations is most sensitive to temperature and grows upon quenching while that of the others remains relatively stable. The thermal behavior of the structure factors follows the Debye model up to the supercooled liquid temperature. The structural investigation of amorphous Ti50Cu50 demonstrates that there exist a variety of polyhedral configurations in Ti50Cu50 amorphous alloy, where icosahedral and bcc clusters are the major types. Due to the existence of bcc clusters and the other distorted polyhedra other than full icosahedra, the structural analysis reconfirms the inference from the Gibbs free energy calculation.

  18. Preliminary Tests of Blowers of Three Designs Operating in Conjunction with a Wing-Duct Cooling System for Radial Engines, Special Report

    Science.gov (United States)

    Biermann, David; Valentine, E. Floyd

    1939-01-01

    This paper is one of several dealing with methods intended to reduce the drag of present-day radial engine installations and improve the cooling at zero and low air speeds, The present paper describes model wind-tunnel tests of blowers of three designs tested in conjunction with a wing-nacelle combination. The principle of operation involved consists of drawing cooling air into ducts located in the wing root at the point of maximum slipstream velocity, passing the air through the engine baffles from rear to front, and exhausting the air through an annular slot located between the propeller and the engine with the aid of a blower mounted on the spinner. The test apparatus consisted essentially of a stub wing having a 5-foot chord and a 15-foot span, an engine nacelle of 20 inches diameter enclosing a 25-horsepower electric motor, and three blowers mounted on propeller spinners. Two of the blowers utilize centrifugal force while the other uses the lift from airfoils to force the air out radially through the exit slot. Maximum efficiencies of over 70 percent were obtained for the system as a whole. Pressures were measured over the entire flight range which were in excess of those necessary to cool present-day engines, The results indicated that blowers mounted on propeller spinners could be built sufficiently powerful and efficient to warrant their use as the only, or chief, means of forcing air through the cooling system, so that cooling would be independent of the speed of the airplane.

  19. SENSITIVE LIMITS ON THE MOLECULAR GAS CONTENT OF CLUSTER COOLING FLOWS

    NARCIS (Netherlands)

    MCNAMARA, BR; JAFFE, W

    1994-01-01

    We have searched for molecular gas toward six cluster cooling flows in the CO(2-1) line using the James Clerk Maxwell Telescope. The sample includes clusters with estimated total cooling rates Of m(CF) approximately 10-600M. yr-1, at redshifts between z approximately 0.01-0.06. None were detected ei

  20. Progress towards the laser cooling of the magnesium fluoride molecular beam

    Science.gov (United States)

    Xia, Yong; Dai, Dapeng; Li, Xingjia; Yin, Yanning; Yin, Jianping

    2015-05-01

    Though the laser cooling techniques that have been tremendously successful in producing ultracold atoms are difficult to apply to molecules, in the past few years, a new approach, laser cooling and trapping of diatomic molecules has become possible. We select magnesium fluoride (MgF) as a prototype molecule for laser cooling experiment. In order to compensate the changes of the Doppler shift during the longitudinal slowing of the molecular beam, we theoretically investigate the possibility of stimulated light force deceleration and cooling of the diatomic magnesium fluoride molecular beam with near-cycling transitions in the bichromatic standing light wave of high intensity which estimated by the two-level optical Bloch equations. We also demonstrate a robust and versatile solution for locking the continuous-wave Ti:sapphire tunable laser for applications in laser cooling of molecules which need linewidth-narrowed and frequency-stabilized lasers.

  1. Continuous all-optical deceleration and single-photon cooling of molecular beams

    CERN Document Server

    Jayich, A M; Hummon, M T; Porto, J V; Campbell, W C

    2013-01-01

    Ultracold molecular gases are promising as an avenue to rich many-body physics, quantum chemistry, quantum information, and precision measurements. This richness, which flows from the complex internal structure of molecules, makes the creation of ultracold molecular gases using traditional methods (laser plus evaporative cooling) a challenge, in particular due to the spontaneous decay of molecules into dark states. We propose a way to circumvent this key bottleneck using an all-optical method for decelerating molecules using stimulated absorption and emission with a single ultrafast laser. We further describe single-photon cooling of the decelerating molecules that exploits their high dark state pumping rates, turning the principal obstacle to molecular laser cooling into an advantage. Cooling and deceleration may be applied simultaneously and continuously to load molecules into a trap. We discuss implementation details including multi-level numerical simulations of strontium monohydride (SrH). These techniqu...

  2. BaH molecular spectroscopy with relevance to laser cooling

    Science.gov (United States)

    Tarallo, M. G.; Iwata, G. Z.; Zelevinsky, T.

    2016-03-01

    We describe a simple experimental apparatus for laser ablation of barium monohydride (BaH) molecules and the study of their rovibrational spectra relevant to direct laser cooling. BaH is a promising candidate for laser cooling and ultracold fragmentation, both of which are precursors to novel experiments in many-body physics and precision measurement. We present a detailed analysis of the properties of ablation plumes that can improve the understanding of surface ablation and deposition technologies. A range of absorption spectroscopy and collisional thermalization regimes has been studied. We directly measured the Franck-Condon factor of the B 2Σ+(v'=0 ) ←X 2Σ+(v''=1 ) cycling transition. Prospects for production of a high luminosity cryogenic BaH beam are outlined.

  3. BaH molecular spectroscopy with relevance to laser cooling

    CERN Document Server

    Tarallo, M G; Zelevinsky, T

    2015-01-01

    We describe a simple experimental apparatus for laser ablation of barium monohydride (BaH) molecules and the study of their rovibrational spectra that are relevant to direct laser cooling. We present a detailed analysis of the properties of ablation plumes that can improve the understanding of surface ablation and deposition technologies. A range of absorption spectroscopy and collisional thermalization regimes has been studied. We directly measured the Franck-Condon factor of the $\\mathrm{B}^2\\Sigma^+(v'=0)\\leftarrow\\mathrm{X}^2\\Sigma^+(v"=1)$ transition. Prospects for production of a high luminosity cryogenic BaH beam are outlined. This molecule is a promising candidate for laser cooling and ultracold fragmentation, both of which are precursors to novel experiments in many-body physics and precision measurement.

  4. Application of the stabilization method to the molecular states of LiHeT : Energies and radial couplings

    Energy Technology Data Exchange (ETDEWEB)

    Macias, A.; Mendizabal, R.; Pelayo, F.; Riera, A.; Yaez, M.

    1986-01-01

    We have used the stabilization method to perform calculations on autoionizing states of the LiHeT system which are involved in LiT +He collisions. The molecular energies and radial couplings are calculated with use of programs developed at our laboratory. For both short and large internuclear distances, the stabilization treatment is complemented by block-diagonalization techniques. Our calculations allow us to draw conclusions on the conditions under which these methods can be used to calculate energy positions and radial couplings for states that lie in an ionization continuum.

  5. Different Cooling Rate Dependences of Different Microstructure Units in Aluminium Glass by Molecular Dynamics Simulation

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-Song; ZHU Zhen-Gang; XIA Jun-Chao; SUN De-Yan

    2000-01-01

    Constant-pressure molecular dynamics simulation and the pair analysis technique have been performed to study the microstructural evolution of aluminium during rapid solidification. The microstructure characteristics of icosahedral ordering increase with decrease of the cooling rate, whereas the microstructure unit characteristics of hcp crystalline structure decrease. There are two kinds of microstructure units which are similar to those in the fcc crystal containing interstitialcies. These two kinds of microscopic units are nearly independent of the cooling rate. The microscopic structural unit characteristics of fcc crystalline structure do not depend on the cooling rate either. These results may help us understand the microstructure of glass and its stability.

  6. Modeling of the Radial Heat Flow and Cooling Processes in a Deep Ultraviolet Cu+ Ne-CuBr Laser

    Directory of Open Access Journals (Sweden)

    Iliycho Petkov Iliev

    2009-01-01

    Full Text Available An improved theoretical model of the gas temperature profile in the cross-section of an ultraviolet copper ion excited copper bromide laser is developed. The model is based on the solution of the one-dimensional heat conduction equation subject to special nonlinear boundary conditions, describing the heat interaction between the laser tube and its surroundings. It takes into account the nonuniform distribution of the volume power density along with the radius of the laser tube. The problem is reduced to the boundary value problem of the first kind. An explicit solution of this model is obtained. The model is applied for the evaluation of the gas temperature profiles of the laser in the conditions of free and forced air-cooling. Comparison with other simple models assumed constant volume power density is made. In particular, a simple expression for calculating the average gas temperature is found.

  7. Radial heat flux transformer

    Science.gov (United States)

    Basiulis, A.; Buzzard, R. J.

    1971-01-01

    Unit moves heat radially from small diameter shell to larger diameter shell, or vice versa, with negligible temperature drop, making device useful wherever heating or cooling of concentrically arranged materials, substances, and structures is desired.

  8. Investigation of Reactivity Feedback Mechanism of Axial and Radial Expansion Effect of Metal-Fueled Sodium-Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Seung-Hwan; Choi, Chi-Woong; Jeong, Tae-Kyung; Ha, Gi-Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The major inherent reactivity feedback models for a ceramic fuel used in a conventional light water reactor are Doppler feedback and moderator feedback. The metal fuel has these two reactivity feedback mechanisms previously mentioned. In addition, the metal fuel has two more reactivity feedback models related to the thermal expansion phenomena of the metal fuel. Since the metal fuel has a good capability to expand according to the temperature changes of the core, two more feedback mechanisms exist. These additional two feedback mechanism are important to the inherent safety of metal fuel and can make metal-fueled SFR safer than oxide-fueled SFR. These phenomena have already been applied to safety analysis on design extended condition. In this study, the effect of these characteristics on power control capability was examined through a simple load change operation. The axial expansion mechanism is induced from the change of the fuel temperature according to the change of the power level of PGSFR. When the power increases, the fuel temperatures in the metal fuel will increase and then the reactivity will decrease due to the axial elongation of the metal fuel. To evaluate the expansion effect, 2 cases were simulated with the same scenario by using MMS-LMR code developed at KAERI. The first simulation was to analyze the change of the reactor power according to the change of BOP power without the reactivity feedback model of the axial and radial expansion of the core during the power transient event. That is to say, the core had only two reactivity feedback mechanism of Doppler and coolant temperature.

  9. Continuous all-optical deceleration and single-photon cooling of molecular beams

    Science.gov (United States)

    Jayich, A. M.; Vutha, A. C.; Hummon, M. T.; Porto, J. V.; Campbell, W. C.

    2014-02-01

    Ultracold molecular gases are promising as an avenue to rich many-body physics, quantum chemistry, quantum information, and precision measurements. This richness, which flows from the complex internal structure of molecules, makes the creation of ultracold molecular gases using traditional methods (laser plus evaporative cooling) a challenge, in particular due to the spontaneous decay of molecules into dark states. We propose a way to circumvent this key bottleneck using an all-optical method for decelerating molecules using stimulated absorption and emission with a single ultrafast laser. We further describe single-photon cooling of the decelerating molecules that exploits their high dark state pumping rates, turning the principal obstacle to molecular laser cooling into an advantage. Cooling and deceleration may be applied simultaneously and continuously to load molecules into a trap. We discuss implementation details including multilevel numerical simulations of strontium monohydride. These techniques are applicable to a large number of molecular species and atoms with the only requirement being an electric dipole transition that can be accessed with an ultrafast laser.

  10. Cooling rate dependence of solidification for liquid aluminium: a large-scale molecular dynamics simulation study.

    Science.gov (United States)

    Hou, Z Y; Dong, K J; Tian, Z A; Liu, R S; Wang, Z; Wang, J G

    2016-06-29

    The effect of the cooling rate on the solidification process of liquid aluminium is studied using a large-scale molecular dynamics method. It is found that there are various types of short-range order (SRO) structures in the liquid, among which the icosahedral (ICO)-like structures are dominant. These SRO structures are in dynamic fluctuation and transform each other. The effect of the cooling rate on the microstructure is very weak at high temperatures and in supercooled liquids, and it appears only below the liquid-solid transition temperature. Fast cooling rates favour the formation of amorphous structures with ICO-like features, while slow cooling rates favour the formation of FCC crystalline structures. Furthermore, FCC and HCP structures can coexist in crystalline structures. It is also found that nanocrystalline aluminium can be achieved at appropriate cooling rates, and its formation mechanism is thoroughly investigated by tracing the evolution of nanoclusters. The arrangement of FCC and HCP atoms in the nanograins displays various twinned structures as observed using visualization analysis, which is different from the layering or phase separation structures observed in the solidification of Lennard-Jones fluids and some metal liquids.

  11. Comb-assisted cavity ring-down spectroscopy of a buffer-gas-cooled molecular beam.

    Science.gov (United States)

    Santamaria, Luigi; Sarno, Valentina Di; Natale, Paolo De; Rosa, Maurizio De; Inguscio, Massimo; Mosca, Simona; Ricciardi, Iolanda; Calonico, Davide; Levi, Filippo; Maddaloni, Pasquale

    2016-06-22

    We demonstrate continuous-wave cavity ring-down spectroscopy of a partially hydrodynamic molecular beam emerging from a buffer-gas-cooling source. Specifically, the (ν1 + ν3) vibrational overtone band of acetylene (C2H2) around 1.5 μm is accessed using a narrow-linewidth diode laser stabilized against a GPS-disciplined rubidium clock via an optical frequency comb synthesizer. As an example, the absolute frequency of the R(1) component is measured with a fractional accuracy of ∼1 × 10(-9). Our approach represents the first step towards the extension of more sophisticated cavity-enhanced interrogation schemes, including saturated absorption cavity ring-down or two-photon excitation, to buffer-gas-cooled molecular beams.

  12. The origin of peculiar molecular bands in cool DQ white dwarfs

    Science.gov (United States)

    Kowalski, P. M.

    2010-09-01

    Aims: The DQ white dwarfs are stars whose atmosphere is enriched with carbon, which for cool stars (Teff fluid-like atmospheres of cool DQ white dwarfs. Methods: In our investigation we use a density functional theory based quantum mechanical approach. Results: The electronic transition energy Te increases monotonically with the helium density (ΔTe (eV)~1.6 ρ (g/cm3)). This causes the Swan absorption to occur at shorter wavelengths compared with unperturbed C2. On the other hand the pressure-induced increase in the vibrational frequency is insufficient to account for the observed Swan bands shifts. Our findings are in line with the shape of the distorted molecular bands observed in DQp stars, but the predicted photospheric density required to reproduce these spectral features is one order of magnitude lower than the one predicted by the current models. This indicates pollution by hydrogen or reflects incomplete knowledge of the properties of fluid-like atmospheres of these stars. Conclusions: Our work shows that at the physical conditions encountered in the fluid-like atmospheres of cool DQ white dwarfs the strong interactions between C2 and helium atoms cause an increase in Te, which should produce a blueward shift of the Swan bands. This is consistent with the observations and indicates that the observed Swan-like molecular bands are most likely the pressure-shifted bands of C2.

  13. Pahs, Ionized Gas, and Molecular Hydrogen in Brightest Cluster Galaxies of Cool Core Clusters of Galaxies

    CERN Document Server

    Donahue, Megan; O'Connell, Robert W; Voit, G Mark; Hoffer, Aaron; McNamara, Brian R; Nulsen, Paul E J

    2011-01-01

    We present measurements of 5-25 {\\mu}m emission features of brightest cluster galaxies (BCGs) with strong optical emission lines in a sample of 9 cool-core clusters of galaxies observed with the Infrared Spectrograph on board the Spitzer Space Telescope. These systems provide a view of dusty molecular gas and star formation, surrounded by dense, X-ray emitting intracluster gas. Past work has shown that BCGs in cool-core clusters may host powerful radio sources, luminous optical emission line systems, and excess UV, while BCGs in other clusters never show this activity. In this sample, we detect polycyclic aromatic hydrocarbons (PAHs), extremely luminous, rotationally-excited molecular hydrogen line emission, forbidden line emission from ionized gas ([Ne II] and [Ne III]), and infrared continuum emission from warm dust and cool stars. We show here that these BCGs exhibit more luminous forbidden neon and H2 rotational line emission than star-forming galaxies with similar total infrared luminosities, as well as ...

  14. Efficient stimulated slowing and cooling of the magnesium fluoride molecular beam

    Science.gov (United States)

    Dai, Dapeng; Xia, Yong; Fang, Yinfei; Xu, Liang; Yin, Yanning; Li, Xingjia; Yang, Xiuxiu; Yin, Jianping

    2015-04-01

    We theoretically investigate the possibility of stimulated light force deceleration and cooling of the diatomic magnesium fluoride molecular beam with near-cycling transitions in the bichromatic standing light wave of high intensity. The weighted degeneracy and force reduction factor are considered due to the behavior of the optical bichromatic force (BCF) in near-cycling transitions with internal degeneracies, and the two-level optical Bloch equations can estimate the actual behavior of the BCF. Our simulation shows that the stimulated force exceeding the spontaneous force by a factor of 2.8 can slow down the molecular beam to several m s-1 within centimeter-scale distance, and this slowing mechanism can eliminate the need of compensation of Doppler shift during the longitudinal deceleration of the molecular beam.

  15. Molecular Cooling as a Probe of Star Formation: Spitzer Looking Forward to Herschel

    Science.gov (United States)

    Bergin, Edwin A.; Maret, Sebastien; Yuan, Yuan; Sonnentrucker, Paule; Green, Joel D.; Watson, Dan M.; Harwit, Martin O.; Kristensen, Lars E.; Melnick, Gary J.; Tolls, Volker; Werner, Michael W.; Willacy, Karen

    2009-01-01

    We explore here the question of how cloud physics can be more directly probed when one observes the majority of cooling emissions from molecular gas. For this purpose we use results from a recent Spitzer Space Telescope study of the young cluster of embedded objects in NGC1333. For this study we mapped the emission from eight pure H2 rotational lines, from S(0) to S(7). The H2 emission appears to be associated with the warm gas shocked by the multiple outflows present in the region. The H2 lines are found to contribute to 25 - 50% of the total outflow luminosity, and can be used to more directly ascertain the importance of star formation feedback on the natal cloud. From these lines, we determine the outflow mass loss rate and, indirectly, the stellar infall rate, the outflow momentum and the kinetic energy injected into the cloud over the embedded phase. The latter is found to exceed the binding energy of individual cores, suggesting that outflows could be the main mechanism for cores disruption. Given the recent launch of Herschel and the upcoming operational lifetime of SOFIA we discuss how studies of molecular cooling can take a step beyond understanding thermal balance to exploring the origin, receipt, and transfer of energy in atomic and molecular gas in a wide range of physical situations.

  16. Molecular dissociation and shock-induced cooling in fluid nitrogen at high densities and temperatures

    Science.gov (United States)

    Radousky, H. B.; Nellis, W. J.; Ross, M.; Hamilton, D. C.; Mitchell, A. C.

    1986-01-01

    Radiative temperatures and electrical conductivities were measured for fluid nitrogen compressed dynamically to pressures of 18-90 GPa, temperatures of 4000-14,000 K, and densities of 2-3 g/cu cm. The data show a continuous phase transition above 30 GPa shock pressure and confirm that (delta-P/delta-T)v is less than 0, as indicated previously by Hugoniot equation-of-state experiments. The first observation of shock-induced cooling is also reported. The data are interpreted in terms of molecular dissociation, and the concentration of dissociated molecules is calculated as a function of density and temperature.

  17. Evaporative cooling of microscopic water droplets in vacuo: Molecular dynamics simulations and kinetic gas theory.

    Science.gov (United States)

    Schlesinger, Daniel; Sellberg, Jonas A; Nilsson, Anders; Pettersson, Lars G M

    2016-03-28

    In the present study, we investigate the process of evaporative cooling of nanometer-sized droplets in vacuum using molecular dynamics simulations with the TIP4P/2005 water model. The results are compared to the temperature evolution calculated from the Knudsen theory of evaporation which is derived from kinetic gas theory. The calculated and simulation results are found to be in very good agreement for an evaporation coefficient equal to unity. Our results are of interest to experiments utilizing droplet dispensers as well as to cloud micro-physics.

  18. Molecular Dynamics Simulation Studies on the Cooling Process of Polyvinyl Chloride

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    By means of molecular dynamics simulation, the transition of the conformations of polyvinyl chloride during a cooling process from 600 to 300 K was studied. The results show that the amorphous polyvinyl chloride chain experiences the melting state, elastic state and glass state and the conformations can be characterized by the increases of the trans-state of C-C-C-C and the near gauche-state of C-C-C-Cl with the decrease of temperature. It is found that the transition of the conformations is driven mainly by the Coulomb interaction between chain segments.

  19. Dynamical cooling of galactic discs by molecular cloud collisions - origin of giant clumps in gas-rich galaxy discs

    Science.gov (United States)

    Li, Guang-Xing

    2017-10-01

    Different from Milky Way-like galaxies, discs of gas-rich galaxies are clumpy. It is believed that the clumps form because of gravitational instability. However, a necessary condition for gravitational instability to develop is that the disc must dissipate its kinetic energy effectively, this energy dissipation (also called cooling) is not well understood. We propose that collisions (coagulation) between molecular clouds dissipate the kinetic energy of the discs, which leads to a dynamical cooling. The effectiveness of this dynamical cooling is quantified by the dissipation parameter D, which is the ratio between the free-fall time t_ff≈ 1/ √{G ρ _{disc}} and the cooling time determined by the cloud collision process tcool. This ratio is related to the ratio between the mean surface density of the disc Σdisc and the mean surface density of molecular clouds in the disc Σcloud. When D cloud), cloud collision cooling is inefficient, and fragmentation is suppressed. When D > 1/3 (which roughly corresponds to Σdisc > 1/3Σcloud), cloud-cloud collisions lead to a rapid cooling through which clumps form. On smaller scales, cloud-cloud collisions can drive molecular cloud turbulence. This dynamical cooling process can be taken into account in numerical simulations as a sub-grid model to simulate the global evolution of disc galaxies.

  20. Theory of vibrational cooling in molecular crystals: Application to crystalline naphthalene

    Science.gov (United States)

    Hill, Jeffrey R.; Dlott, Dana D.

    1988-07-01

    The process of vibrational cooling (VC) is theoretically investigated in the molecular crystal naphthalene. Specificially we consider the process where a highly excited vibration cools by emitting lower energy vibrations (vibrational relaxation, or VR) and phonons. We also consider the subsequent cooling of emitted optic phonons by emission of acoustic phonons. Using previously determined vibrational lifetimes [J. R. Hill et al., J. Chem. Phys. 88, 949 (1988)], a consistent transition rate matrix is obtained which describes VR of all vibrations and optic phonons at all temperatures. Then a Master equation is solved numerically to obtain the time dependent vibrational populations of all states following impulse excitation of a high frequency vibration. These results are compared to a previously derived analytic model for VC in molecular crystals [J. R. Hill and D. D. Dlott, J. Chem. Phys. 89, 830 (1988)]. In that theory, which is shown to be in good agreement with the naphthalene calculation, the excess vibrational excitation moves to lower energy states and broadens as time increases. The motion toward lower energy states is described by a temperature independent ``vibrational velocity'' (emitted energy per unit time). In naphthalene, the vibrational velocity is V0 ≊9 cm-1 /ps. The VC process occurs on a time scale as much as an order of magnitude longer than an individual VR step. Although VR is highly temperature dependent, VC is not. The VC calculations are used to predict the decay from the initial state, the time dependent populations of transient vibrational excitations, and the return to the vibrationless ground state. All these quantities are directly related to experimental observables such as incoherent anti-Stokes Raman scattering and hot luminescence.

  1. Cooling arrangement for a tapered turbine blade

    Science.gov (United States)

    Liang, George

    2010-07-27

    A cooling arrangement (11) for a highly tapered gas turbine blade (10). The cooling arrangement (11) includes a pair of parallel triple-pass serpentine cooling circuits (80,82) formed in an inner radial portion (50) of the blade, and a respective pair of single radial channel cooling circuits (84,86) formed in an outer radial portion (52) of the blade (10), with each single radial channel receiving the cooling fluid discharged from a respective one of the triple-pass serpentine cooling circuit. The cooling arrangement advantageously provides a higher degree of cooling to the most highly stressed radially inner portion of the blade, while providing a lower degree of cooling to the less highly stressed radially outer portion of the blade. The cooling arrangement can be implemented with known casting techniques, thereby facilitating its use on highly tapered, highly twisted Row 4 industrial gas turbine blades that could not be cooled with prior art cooling arrangements.

  2. Molecular Dynamics Simulations of Aqueous and Confined Systems Relevant to the Supercritical Water Cooled Nuclear Reactor

    Science.gov (United States)

    Kallikragas, Dimitrios Theofanis

    Supercritical water (SCW) is the intended heat transfer fluid and potential neutron moderator in the proposed GEN-IV Supercritical Water Cooled Reactor (SCWR). The oxidative environment poses challenges in choosing appropriate design materials, and the behaviour of SCW within crevices of the passivation layer is needed for developing a corrosion control strategy to minimize corrosion. Molecular Dynamics simulations have been employed to obtain diffusion coefficients, coordination number and surface density characteristics, of water and chloride in nanometer-spaced iron hydroxide surfaces. Diffusion models for hydrazine are evaluated along with hydration data. Results demonstrate that water is more likely to accumulate on the surface at low density conditions. The effect of confinement on the water structure diminishes as the gap size increases. The diffusion coefficient of chloride decreases with larger surface spacing. Clustering of water at the surface implies that the SCWR will be most susceptible to pitting corrosion and stress corrosion cracking.

  3. Laser cooling of new atomic and molecular species with ultrafast pulses

    OpenAIRE

    Kielpinski, David

    2005-01-01

    We propose a new laser cooling method for atomic species whose level structure makes traditional laser cooling difficult. For instance, laser cooling of hydrogen requires single-frequency vacuum-ultraviolet light, while multielectron atoms need single-frequency light at many widely separated frequencies. These restrictions can be eased by laser cooling on two-photon transitions with ultrafast pulse trains. Laser cooling of hydrogen, antihydrogen, and many other species appears feasible, and e...

  4. Temporal and radial dependent profiles for surface heat transfer during R404a spray cooling%R404a喷雾冷却表面传热特性的时空不均匀性

    Institute of Scientific and Technical Information of China (English)

    王锐; 周致富; 白飞龙; 陈斌; 王国祥

    2015-01-01

    Cryogen spray cooling has been applied to protect epidermis from thermal damage during laser surgery. However, the presently used cryogen, R134a shows unsatisfactory efficacy in minimizing laser energy absorption by melanin in darkly pigmented human skins. Previous work of our group showed that R404a had the potential of improving cooling protection to epidermis, while there is few related research on the surface heat transfer during R404a spray cooling. This paper presents an experimental study on the temporal and radial variation in temperature and heat flux during spray cooling using R404a by a specially designed nozzle with expansion chamber, which significantly improved the atomization effect. The temporal and radial conditions strongly influenced uniformity of surface heat transfer. However, there existed a sub-region of uniform cooling with radius of 2 mm around spray center with high heat flux. The result of this experiment could provide guidance for guaranteeing uniform cooling protection during clinical laser surgery.%制冷剂瞬态喷雾冷却是辅助激光手术治疗皮肤病的重要手段,目前采用的R134a制冷剂不易抵消深色人种表皮中的黑色素对激光能量的大量吸收,采用沸点较低的R404a制冷剂能更有效防止表皮的热损伤。使用带膨胀腔的新型喷嘴搭建了瞬态喷雾冷却实验台,采用薄膜热电偶快速测温技术对R404a瞬态喷雾冷却表面传热特性进行了研究。结果表明,R404喷雾冷却表面传热具有时间和空间的不均匀性,然而在喷雾中心半径2 mm的中心区域内存在高热通量的均匀冷却区域。在实际激光皮肤临床手术中,参考实验结果可保证喷雾冷却对治疗范围内的表皮进行均匀冷保护。

  5. The Cool ISM in S0 Galaxies. I. A Survey of Molecular Gas

    CERN Document Server

    Welch, G A; Welch, Gary A.; Sage, Leslie J.

    2003-01-01

    Lenticular galaxies remain remarkably mysterious as a class. Observations to date have not led to any broad consensus about their origins, properties and evolution, though they are often thought to have formed in one big burst of star formation early in the history of the Universe, and to have evolved relatively passively since then. In that picture, current theory predicts that stellar evolution returns substantial quantities of gas to the interstellar medium; most is ejected from the galaxy, but significant amounts of cool gas might be retained. Past searches for that material, though, have provided unclear results. We present results from a survey of molecular gas in a volume-limited sample of field S0 galaxies, selected from the Nearby Galaxies Catalog. CO emission is detected from 78 percent of the sample galaxies. We find that the molecular gas is almost always located inside the central few kiloparses of a lenticular galaxy, meaning that in general it is more centrally concentrated than in spirals. We ...

  6. Single-Cylinder Engine Tests of Porous Chrome-Plated Cylinder Barrels with Special Bore Coatings for Radial Air-Cooled Engines

    Science.gov (United States)

    1946-01-01

    sulphamate solution at room temperature having a hydrogen-ion concentration of 1.5. The cylinder was plated for 2 minutes with a current density of 40...for any metal combination (reference 3), engine friction may be reduced somewhat by the use of a silver overplate as a bearing material on the...Cooled Engines. NACA ARR No. E5L18, 1945. 3. Hoyt, Samuel L.: Metals and Alloys Data Book. Reinhold Pub. Corp., 1943, p. 281. 4. Downing, B. F

  7. Molecular dynamics study on the solvent dependent heme cooling following ligand photolysis in carbonmonoxy myoglobin.

    Science.gov (United States)

    Zhang, Yong; Fujisaki, Hiroshi; Straub, John E

    2007-03-29

    The time scale and mechanism of vibrational energy relaxation of the heme moiety in myoglobin was studied using molecular dynamics simulation. Five different solvent models, including normal water, heavy water, normal glycerol, deuterated glycerol and a nonpolar solvent, and two forms of the heme, one native and one lacking acidic side chains, were studied. Structural alteration of the protein was observed in native myoglobin glycerol solution and native myoglobin water solution. The single-exponential decay of the excess kinetic energy of the heme following ligand photolysis was observed in all systems studied. The relaxation rate depends on the solvent used. However, this dependence cannot be explained using bulk transport properties of the solvent including macroscopic thermal diffusion. The rate and mechanism of heme cooling depends upon the detailed microscopic interaction between the heme and solvent. Three intermolecular energy transfer mechanisms were considered: (i) energy transfer mediated by hydrogen bonds, (ii) direct vibration-vibration energy transfer via resonant interaction, and (iii) energy transfer via vibration-translation or vibration-rotation interaction, or in other words, thermal collision. The hydrogen bond interaction and vibration-vibration interaction between the heme and solvent molecules dominates the energy transfer in native myoglobin aqueous solution and native myoglobin glycerol solutions. For modified myoglobin, the vibration-vibration interaction is also effective in glycerol solution, different from aqueous solution. Thermal collisions form the dominant energy transfer pathway for modified myoglobin in water solution, and for both native myoglobin and modified myoglobin in a nonpolar environment. For native myoglobin in a nonpolar solvent solution, hydrogen bonds between heme isopropionate side chains and nearby protein residues, absent in the modified myoglobin nonpolar solvent solution, are key interactions influencing the

  8. COOL: A code for Dynamic Monte Carlo Simulation of molecular dynamics

    Science.gov (United States)

    Barletta, Paolo

    2012-02-01

    Cool is a program to simulate evaporative and sympathetic cooling for a mixture of two gases co-trapped in an harmonic potential. The collisions involved are assumed to be exclusively elastic, and losses are due to evaporation from the trap. Each particle is followed individually in its trajectory, consequently properties such as spatial densities or energy distributions can be readily evaluated. The code can be used sequentially, by employing one output as input for another run. The code can be easily generalised to describe more complicated processes, such as the inclusion of inelastic collisions, or the possible presence of more than two species in the trap. New version program summaryProgram title: COOL Catalogue identifier: AEHJ_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHJ_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1 097 733 No. of bytes in distributed program, including test data, etc.: 18 425 722 Distribution format: tar.gz Programming language: C++ Computer: Desktop Operating system: Linux RAM: 500 Mbytes Classification: 16.7, 23 Catalogue identifier of previous version: AEHJ_v1_0 Journal reference of previous version: Comput. Phys. Comm. 182 (2011) 388 Does the new version supersede the previous version?: Yes Nature of problem: Simulation of the sympathetic process occurring for two molecular gases co-trapped in a deep optical trap. Solution method: The Direct Simulation Monte Carlo method exploits the decoupling, over a short time period, of the inter-particle interaction from the trapping potential. The particle dynamics is thus exclusively driven by the external optical field. The rare inter-particle collisions are considered with an acceptance/rejection mechanism, that is, by comparing a random number to the collisional probability

  9. Modeling gasodynamic vortex cooling

    Science.gov (United States)

    Allahverdyan, A. E.; Fauve, S.

    2017-08-01

    We aim at studying gasodynamic vortex cooling in an analytically solvable, thermodynamically consistent model that can explain limitations on the cooling efficiency. To this end, we study an angular plus radial flow between two (coaxial) rotating permeable cylinders. Full account is taken of compressibility, viscosity, and heat conductivity. For a weak inward radial flow the model qualitatively describes the vortex cooling effect, in terms of both temperature and the decrease of the stagnation enthalpy, seen in short uniflow vortex (Ranque) tubes. The cooling does not result from external work and its efficiency is defined as the ratio of the lowest temperature reached adiabatically (for the given pressure gradient) to the lowest temperature actually reached. We show that for the vortex cooling the efficiency is strictly smaller than 1, but in another configuration with an outward radial flow, we find that the efficiency can be larger than 1. This is related to both the geometry and the finite heat conductivity.

  10. One-dimensional modeling of radial heat removal during depressurized heatup transients in modular pebble-bed and prismatic high temperature gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Savage, M.G.

    1984-07-01

    A one-dimensional computational model was developed to evaluate the heat removal capabilities of both prismatic-core and pebble-bed modular HTGRs during depressurized heatup transients. A correlation was incorporated to calculate the temperature- and neutron-fluence-dependent thermal conductivity of graphite. The modified Zehner-Schluender model was used to determine the effective thermal conductivity of a pebble bed, accounting for both conduction and radiation. Studies were performed for prismatic-core and pebble-bed modular HTGRs, and the results were compared to analyses performed by GA and GR, respectively. For the particular modular reactor design studied, the prismatic HTGR peak temperature was 2152.2/sup 0/C at 38 hours following the transient initiation, and the pebble-bed peak temperature was 1647.8/sup 0/C at 26 hours. These results compared favorably with those of GA and GE, with only slight differences caused by neglecting axial heat transfer in a one-dimensional radial model. This study found that the magnitude of the initial power density had a greater effect on the temperature excursion than did the initial temperature.

  11. Cold molecular gas in the Perseus cluster core - Association with X-ray cavity, Halpha filaments and cooling flow -

    CERN Document Server

    Salomé, P; Crawford, C; Edge, A C; Erlund, M; Fabian, A C; Hatch, N A; Johnstone, R M; Sanders, J S; Wilman, R J

    2006-01-01

    Cold molecular gas has been recently detected in several cooling flow clusters of galaxies where huge optical nebulosities often stand. These optical filaments are tightly linked to the cooling flow and to the related phenomena, like the rising bubbles of relativistic plasma, fed by the radio jets. We present here a map in the CO(2-1) rotational line of the cold molecular gas associated with some Halpha filaments surrounding the central galaxy of the Perseus cluster: NGC 1275. The map, extending to about 50 kpc (135 arcsec) from the center of the galaxy, has been made with the 18-receiver array HERA, at the focus of the IRAM 30m telescope. Although most of the cold gas is concentrated to the center of the galaxy, the CO emission is also clearly associated to the extended filaments conspicuous in ionised gas and could trace a possible reservoir fueling the star formation there. Some of the CO emission is also found where the X-ray gas could cool down more efficiently: at the rims of the central X-ray cavity (w...

  12. Laser cooling of the OH(-) molecular anion in a theoretical investigation.

    Science.gov (United States)

    Wan, Ming-Jie; Huang, Duo-Hui; Yu, You; Zhang, Yun-Guang

    2017-10-03

    The schemes for laser cooling of the OH(-) anion are proposed using an ab initio method. Scalar relativistic corrections are considered using the Douglas-Kroll Hamilton. Spin-orbit coupling (SOC) effects are taken into account at the MRCI+Q level. SOC effects play important roles in the transition properties of the OH(-) anion. Transition strengths for the transition of the OH(-) anion cannot be ignored. Large vibrational branching ratios for the and transitions are determined. Short spontaneous radiative lifetimes for the a(3)Π1 and A(1)Π1 states are also predicted for rapid laser cooling. The vibrational branching loss ratio to the intervening states a(3)Π0 and a(3)Π1 for the transition is small enough to enable the building of a laser cooling project. The three required laser wavelengths for the and transitions are all in the visible region. The results imply the probability of laser cooling of the OH(-) anion via both a spin-forbidden transition and a three-electronic-level transition.

  13. Multi-pass cooling for turbine airfoils

    Science.gov (United States)

    Liang, George

    2011-06-28

    An airfoil for a turbine vane of a gas turbine engine. The airfoil includes an outer wall having pressure and suction sides, and a radially extending cooling cavity located between the pressure and suction sides. A plurality of partitions extend radially through the cooling cavity to define a plurality of interconnected cooling channels located at successive chordal locations through the cooling cavity. The cooling channels define a serpentine flow path extending in the chordal direction. Further, the cooling channels include a plurality of interconnected chambers and the chambers define a serpentine path extending in the radial direction within the serpentine path extending in the chordal direction.

  14. Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments

    Directory of Open Access Journals (Sweden)

    Lijie Li

    2015-10-01

    Full Text Available Cooling towers are a source of Legionnaires’ disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%, 6 (25, 20.7%, 5 (12, 9.9%, 8 (8, 6.6%, 3 (6, 5.0% and 9 (2, 1.6%. All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT, a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR. 92.6% (112/121 and 98.3% (119/121 isolates carried lvh and rtxA respectively and 90.9% (110/121 of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.

  15. Continuous All-Optical Deceleration and Single-Photon Cooling of Molecular Beams

    Science.gov (United States)

    2014-02-21

    transform-limited τ = 7 ps Gaussian pulse. The operating point (highlighted with a white diamond in Fig. 1) corresponds to 4 W of average power focused to a...illustrated by Eq. (2). The cooling laser is detuned 9 MHz from the zero velocity class, which corresponds to a forward velocity near 7 m/s. The...Treacy, IEEE J. Quantum Electron. 5, 454 (1969). [41] J. S. Melinger, S. R. Gandhi , A. Hariharan, J. X. Tull, and W. S. Warren, Phys. Rev. Lett. 68, 2000

  16. Radial velocity signatures of Zeeman broadening

    CERN Document Server

    Reiners, Ansgar; Anglada-Escude, Guillem; Jeffers, Sandra V; Morin, Julien; Zechmeister, Mathias; Kochukhov, Oleg; Piskunov, Nikolai

    2013-01-01

    Stellar activity signatures such as spots and plage can significantly limit the search for extrasolar planets. Current models of activity-induced radial velocity (RV) signals focused on the impact of temperature contrast in spots predicting the signal to diminish toward longer wavelengths. On the other hand, the relative importance of the Zeeman effect on RV measurements should grow with wavelength, because the Zeeman displacement itself grows with \\lambda, and because a magnetic and cool spot contributes more to the total flux at longer wavelengths. We model the impact of active regions on stellar RV measurements including both temperature contrast in spots and Zeeman line broadening. We calculate stellar line profiles using polarized radiative transfer models including atomic and molecular Zeeman splitting from 0.5 to 2.3\\mum. Our results show that the amplitude of the RV signal caused by the Zeeman effect alone can be comparable to that caused by temperature contrast. Furthermore, the RV signal caused by c...

  17. Ultracold molecular spectroscopy: toward the narrow-line cooling of molecules

    Science.gov (United States)

    Kobayashi, Jun; Ogino, Atsushi; Inouye, Shin

    2015-03-01

    A new spectroscopic method that utilizes microwave transition of ultracold molecules is demonstrated. The narrow spectral linewidth (approximately 100 Hz) was guaranteed by preparing molecules at low temperature, and a high signal-to-noise ratio was achieved by preparing a significant fraction of molecules in the target internal state. The repetition rate of the experiment was approximately 10 Hz, which was only limited by the time needed to load ultracold atoms into the magneto-optical trap. To demonstrate the performance, we investigated the hyperfine structures of the vibrational ground states of the {{X}1}{{Σ }+} and {{b}3}{{\\Pi }{{0+}}} states of KRb molecules. This technique not only allows us to pursue the narrow-line laser cooling of KRb molecules, but also provided us with essential information for realizing precision spectroscopies e.g., the search for the temporal variation of the electron-to-proton mass ratio.

  18. Femtosecond quantum dynamics and laser-cooling in thermal molecular systems

    CERN Document Server

    Warmuth, C

    2000-01-01

    of thermal trans-stilbene upon excitation at the omega sub 0 frequency. The experimental results are in good agreement with theoretical analysis. This work deals with coherent and incoherent vibrational phenomena in thermal systems, wave packet motion and laser-cooling. In the first part, the principle of COIN (Coherence Observation by Interference Noise) has been applied as a new approach to measuring wave packet motion. In the experiment pairs of phase-randomized femtosecond pulses with relative delay-time tau prepare interference fluctuations in the excited state population, so the variance of the correlated fluorescence intensity directly mimics the dynamics of the propagating wave packet. The scheme is demonstrated by measuring the vibrational coherence of wave packet-motion in the B-state of gaseous iodine. The COIN-interferograms obtained recover propagation, recurrences, spreading, and revivals as the typical signature of wave packets. Due to the disharmony of the B-state-potential, fractional revival...

  19. Implementation of a single femtosecond optical frequency comb for molecular cooling

    CERN Document Server

    Shi, W

    2010-01-01

    We show that a single femtosecond optical frequency comb may be used to induce two-photon transitions between molecular vibrational levels to form ultracold molecules, e.g., KRb. The phase across an individual pulse in the pulse train is sinusoidally modulated with a carefully chosen amplitude and modulation frequency. Piecewise adiabatic population transfer is fulfilled to the final state by each pulse in the applied pulse train providing a controlled population accumulation in the final state. Detuning the pule train parameters to less than the frequency difference between the initial and final states changes the time scale of molecular dynamics but leads to the same complete population transfer to the cold state.

  20. ISR Radial Field Magnet

    CERN Multimedia

    1983-01-01

    There were 37 (normal) + 3 (special) Radial Field magnets in the ISR to adjust vertically the closed orbit. Gap heights and strengths were 200 mm and .12 Tm in the normal magnets, 220 mm and .18 Tm in the special ones. The core length was 430 mm in both types. Due to their small length as compared to the gap heights the end fringe field errors were very important and had to be compensated by suitably shaping the poles. In order to save on cables, as these magnets were located very far from their power supplies, the coils of the normal type magnets were formed by many turns of solid cpper conductor with some interleaved layers of hollow conductor directly cooled by circulating water

  1. Molecular typing of Legionella pneumophila from air-conditioning cooling waters using mip gene, SBT, and FAFLP methods.

    Science.gov (United States)

    Gong, Xiangli; Li, Juntao; Zhang, Ying; Hou, Shuiping; Qu, Pinghua; Yang, Zhicong; Chen, Shouyi

    2017-08-01

    Legionella spp. are important waterborne pathogens. Molecular typing has become an important method for outbreaks investigations and source tracking of Legionnaires. In a survey program conducted by the Guangzhou Center for Disease Control and Prevention, multiple serotypes Legionella pneumophila (L. pneumophila) were isolated from waters in air-conditioning cooling towers in urban Guangzhou region, China between 2008 and 2011. Three genotyping methods, mip (macrophage infectivity potentiator) genotyping, SBT (sequence-based typing), and FAFLP (fluorescent amplified fragment length polymorphism analysis) were used to type these waterborne L. pneumophila isolates. The three methods were capable of typing all the 134 isolates and a reference strain of L. pneumophila (ATCC33153), with discriminatory indices of 0.7034, 0.9218, and 0.9376, for the mip, SBT, and FAFLP methods respectively. Among the 9 serotypes of the 134 isolates, 10, 50, and 34 molecular types were detected by the mip, SBT, and FAFLP methods respectively. The mip genotyping and SBT typing are more feasible for inter-laboratory results sharing and comparison of different types of L. pneumophila. The SBT and FAFLP typing methods were rapid with higher discriminatory abilities. Combinations of two or more of the typing methods enables more accurate typing of Legionella isolates for outbreak investigations and source tracking of Legionnaires. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Optical dipole-force cooling of anions in a Penning trap

    Science.gov (United States)

    Fesel, Julian; Gerber, Sebastian; Doser, Michael; Comparat, Daniel

    2017-09-01

    We discuss the possibility of using optical dipole forces for Sisyphus cooling of ions stored in a Penning trap by addressing the specific case of the molecular cooling candidate C2 -. Using a GPU accelerated code for Penning trap simulations, which we extended to include the molecule-light interaction, we show that this scheme can decrease the time required for cooling by an order of magnitude with respect to Doppler cooling. In our simulation we found that a reduction of the axial anion temperature from 10 K to 50 mK in around 10 s is possible. The temperature of the radial degrees of freedom was seen to thermalize to 150 mK . Based on the laser-cooled C2 -, a study on the sympathetic cooling of anions with masses 1-50 nucleon was performed, covering relevant candidates for investigations of chemical anion reactions at ultracold temperatures as well as for antimatter studies.

  3. Characterization of an atrazine molecularly imprinted polymer prepared by a cooling method

    Science.gov (United States)

    Royani, Idha; Widayani, Abdullah, Mikrajuddin; Khairurrijal

    2014-03-01

    A molecularly imprinted polymer (MIP) for atrazine was successfully prepared. Atrazine molecules as templates were incorporated into the pre-polymerization solution containing a functional monomer (methacrylic acid), a cross-linker (ethylene glycol dimethacrylate), and an initiator (benzoyl peroxide). The placement of a tube containing the pre-polymerization solution into a freezer was done to replace nitrogen pouring into the pre-polymerization solution. The sensing characteristic of the obtained MIP was examined and it was found that the amount of atrazine bound to the cavities in the MIP increases with increasing the initial concentration of atrazine. From Scatchard plots, it was found that the equilibrium dissociation constant KD and the apparent maximum number of binding sites Bmax, which are written as (KD, Bmax), are (6.4 μM, 13.41 mmol/g) and (6.5 μM, 4.55 mmol/g) for the 10 and 30 mg of MIP, respectively.

  4. Cooling molecular vibrations with shaped laser pulses: Optimal control theory exploiting the timescale separation between coherent excitation and spontaneous emission

    CERN Document Server

    Reich, Daniel M

    2013-01-01

    Laser cooling of molecules employing broadband optical pumping involves a timescale separation between laser excitation and spontaneous emission. Here, we optimize the optical pumping step using shaped laser pulses. We derive two optimization functionals to drive population into those excited state levels that have the largest spontaneous emission rates to the target state. We show that, when using optimal control, laser cooling of molecules works even if the Franck-Condon map governing the transitions is preferential to heating rather than cooling. Our optimization functional is also applicable to the laser cooling of other degrees of freedom provided the cooling cycle consists of coherent excitation and dissipative deexcitation steps whose timescales are separated.

  5. Laser cooling of dense atomic gases by collisional redistribution of radiation and spectroscopy of molecular dimers in a dense buffer gas environment

    CERN Document Server

    Saß, Anne; Christopoulos, Stavros; Knicker, Katharina; Moroshkin, Peter; Weitz, Martin

    2014-01-01

    We study laser cooling of atomic gases by collisional redistribution of fluorescence. In a high pressure buffer gas regime, frequent collisions perturb the energy levels of alkali atoms, which allows for the absorption of a far red detuned irradiated laser beam. Subsequent spontaneous decay occurs close to the unperturbed resonance frequency, leading to a cooling of the dense gas mixture by redistribution of fluorescence. Thermal deflection spectroscopy indicates large relative temperature changes down to and even below room temperature starting from an initial cell temperature near 700 K. We are currently performing a detailed analysis of the temperature distribution in the cell. As we expect this cooling technique to work also for molecular-noble gas mixtures, we also present initial spectroscopic experiments on alkali-dimers in a dense buffer gas surrounding.

  6. Stacking with stochastic cooling

    Energy Technology Data Exchange (ETDEWEB)

    Caspers, Fritz E-mail: Fritz.Caspers@cern.ch; Moehl, Dieter

    2004-10-11

    Accumulation of large stacks of antiprotons or ions with the aid of stochastic cooling is more delicate than cooling a constant intensity beam. Basically the difficulty stems from the fact that the optimized gain and the cooling rate are inversely proportional to the number of particles 'seen' by the cooling system. Therefore, to maintain fast stacking, the newly injected batch has to be strongly 'protected' from the Schottky noise of the stack. Vice versa the stack has to be efficiently 'shielded' against the high gain cooling system for the injected beam. In the antiproton accumulators with stacking ratios up to 10{sup 5} the problem is solved by radial separation of the injection and the stack orbits in a region of large dispersion. An array of several tapered cooling systems with a matched gain profile provides a continuous particle flux towards the high-density stack core. Shielding of the different systems from each other is obtained both through the spatial separation and via the revolution frequencies (filters). In the 'old AA', where the antiproton collection and stacking was done in one single ring, the injected beam was further shielded during cooling by means of a movable shutter. The complexity of these systems is very high. For more modest stacking ratios, one might use azimuthal rather than radial separation of stack and injected beam. Schematically half of the circumference would be used to accept and cool new beam and the remainder to house the stack. Fast gating is then required between the high gain cooling of the injected beam and the low gain stack cooling. RF-gymnastics are used to merge the pre-cooled batch with the stack, to re-create free space for the next injection, and to capture the new batch. This scheme is less demanding for the storage ring lattice, but at the expense of some reduction in stacking rate. The talk reviews the 'radial' separation schemes and also gives some

  7. Effects of 'Cooled' Cooling Air on Pre-Swirl Nozzle Design

    Science.gov (United States)

    Scricca, J. A.; Moore, K. D.

    2006-01-01

    It is common practice to use Pre-Swirl Nozzles to facilitate getting the turbine blade cooling air onboard the rotating disk with minimum pressure loss and reduced temperature. Higher engine OPR's and expanded aircraft operating envelopes have pushed cooling air temperatures to the limits of current disk materials and are stressing the capability to cool the blade with practical levels of cooling air flow. Providing 'Cooled' Cooling Air is one approach being considered to overcome these limitations. This presentation looks at how the introduction of 'Cooled' Cooling Air impacts the design of the Pre-Swirl Nozzles, specifically in relation to the radial location of the nozzles.

  8. Sequential cooling insert for turbine stator vane

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Russel B

    2017-04-04

    A sequential flow cooling insert for a turbine stator vane of a small gas turbine engine, where the impingement cooling insert is formed as a single piece from a metal additive manufacturing process such as 3D metal printing, and where the insert includes a plurality of rows of radial extending impingement cooling air holes alternating with rows of radial extending return air holes on a pressure side wall, and where the insert includes a plurality of rows of chordwise extending second impingement cooling air holes on a suction side wall. The insert includes alternating rows of radial extending cooling air supply channels and return air channels that form a series of impingement cooling on the pressure side followed by the suction side of the insert.

  9. Cooled particle accelerator target

    Science.gov (United States)

    Degtiarenko, Pavel V.

    2005-06-14

    A novel particle beam target comprising: a rotating target disc mounted on a retainer and thermally coupled to a first array of spaced-apart parallel plate fins that extend radially inwardly from the retainer and mesh without physical contact with a second array of spaced-apart parallel plate fins that extend radially outwardly from and are thermally coupled to a cooling mechanism capable of removing heat from said second array of spaced-apart fins and located within the first array of spaced-apart parallel fins. Radiant thermal exchange between the two arrays of parallel plate fins provides removal of heat from the rotating disc. A method of cooling the rotating target is also described.

  10. Cooling circuit for a gas turbine bucket and tip shroud

    Energy Technology Data Exchange (ETDEWEB)

    Willett, Fred Thomas (25 Long Creek Dr., Burnt Hills, NY 12027); Itzel, Gary Michael (12 Cider Mill Dr., Clifton Park, NY 12065); Stathopoulos, Dimitrios (11 Wyngate Rd., Glenmont, NY 12077); Plemmons, Larry Wayne (late of Hamilton, OH); Plemmons, Helen M. (2900 Long Ridge Trails, Hamilton, OH 45014); Lewis, Doyle C. (444 River Way, Greer, SC 29651)

    2002-01-01

    An open cooling circuit for a gas turbine bucket wherein the bucket has an airfoil portion, and a tip shroud, the cooling circuit including a plurality of radial cooling holes extending through the airfoil portion and communicating with an enlarged internal area within the tip shroud before exiting the tip shroud such that a cooling medium used to cool the airfoil portion is subsequently used to cool the tip shroud.

  11. Molecular characterization of viable Legionella spp. in cooling tower water samples by combined use of ethidium monoazide and PCR.

    Science.gov (United States)

    Inoue, Hiroaki; Fujimura, Reiko; Agata, Kunio; Ohta, Hiroyuki

    2015-01-01

    Viable Legionella spp. in environmental water samples were characterized phylogenetically by a clone library analysis combining the use of ethidium monoazide and quantitative PCR. To examine the diversity of Legionella spp., six cooling tower water samples and three bath water samples were collected and analyzed. A total of 617 clones were analyzed for their 16S rRNA gene sequences and classified into 99 operational taxonomic units (OTUs). The majority of OTUs were not clustered with currently described Legionella spp., suggesting the wide diversity of not-yet-cultured Legionella groups harbored in cooling tower water environments.

  12. Rotational state resolved photodissociation spectroscopy of translationally and vibrationally cold MgH+ ions: toward rotational cooling of molecular ions

    DEFF Research Database (Denmark)

    Højbjerre, Klaus; Hansen, Anders Kragh; Skyt, Peter Sandegaard

    2009-01-01

    and vibrationally cold MgH+ ions are presented, with and without the optical pumping laser being present. While rotational cooling is as yet not evident, first results showed evidence of a change in the rotational distribution in the presence of the optical pumping laser.......The first steps toward the implementation of a simple scheme for rotational cooling of MgH+ ions based on rotational state optical pumping is considered. The various aspects of such an experiment are described in detail, and the rotational state-selective dissociation spectra of translationally...

  13. Electron cooling

    Science.gov (United States)

    Meshkov, I.; Sidorin, A.

    2004-10-01

    The brief review of the most significant and interesting achievements in electron cooling method, which took place during last two years, is presented. The description of the electron cooling facilities-storage rings and traps being in operation or under development-is given. The applications of the electron cooling method are considered. The following modern fields of the method development are discussed: crystalline beam formation, expansion into middle and high energy electron cooling (the Fermilab Recycler Electron Cooler, the BNL cooler-recuperator, cooling with circulating electron beam, the GSI project), electron cooling in traps, antihydrogen generation, electron cooling of positrons (the LEPTA project).

  14. Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Blaskiewicz, M.

    2011-01-01

    Stochastic Cooling was invented by Simon van der Meer and was demonstrated at the CERN ISR and ICE (Initial Cooling Experiment). Operational systems were developed at Fermilab and CERN. A complete theory of cooling of unbunched beams was developed, and was applied at CERN and Fermilab. Several new and existing rings employ coasting beam cooling. Bunched beam cooling was demonstrated in ICE and has been observed in several rings designed for coasting beam cooling. High energy bunched beams have proven more difficult. Signal suppression was achieved in the Tevatron, though operational cooling was not pursued at Fermilab. Longitudinal cooling was achieved in the RHIC collider. More recently a vertical cooling system in RHIC cooled both transverse dimensions via betatron coupling.

  15. Stacking with Stochastic Cooling

    CERN Document Server

    Caspers, Friedhelm

    2004-01-01

    Accumulation of large stacks of antiprotons or ions with the aid of stochastic cooling is more delicate than cooling a constant intensity beam. Basically the difficulty stems from the fact that the optimized gain and the cooling rate are inversely proportional to the number of particles seen by the cooling system. Therefore, to maintain fast stacking, the newly injected batch has to be strongly protected from the Schottky noise of the stack. Vice versa the stack has to be efficiently shielded against the high gain cooling system for the injected beam. In the antiproton accumulators with stacking ratios up to 105, the problem is solved by radial separation of the injection and the stack orbits in a region of large dispersion. An array of several tapered cooling systems with a matched gain profile provides a continuous particle flux towards the high-density stack core. Shielding of the different systems from each other is obtained both through the spatial separation and via the revolution frequencies (filters)....

  16. 径向流分子筛使用末期CO2含量超标的处理%Treatment of Excessive CO2 Content at the Final Phase of Radial Flow Molecular Sieve Usage

    Institute of Scientific and Technical Information of China (English)

    长孙峰; 高永春

    2015-01-01

    Excessive carbon dioxide content in the air from the outlet of radial flow molecular sieve absorber at the end of adsorption affects the safe operation of air separation plant. The causes of the trouble were analyzed from the aspects of technical design, molecular sieve operation parameters and equipment factors and countermeasures were taken, which has solved the problem.%径向流分子筛在使用过程末期CO2含量超高,影响空分安全运行。从工艺设计、分子筛运行参数和设备等方面分析了原因,并采取措施解决了问题。

  17. Extensive theoretical study on electronically excited states of calcium monochloride: Molecular laser cooling and production of ultracold chlorine atoms

    Science.gov (United States)

    Fu, Mingkai; Ma, Haitao; Cao, Jianwei; Bian, Wensheng

    2016-05-01

    Nine doublet Λ-S states of calcium monochloride (CaCl) are calculated using the internally contracted multireference configuration interaction method with the Davidson correction. Both the core subvalence and spin-orbit coupling effects are taken into account. Laser cooling of CaCl and production of ultracold chlorine atoms are investigated and assessed. Our computed spectroscopic constants and radiative lifetimes match the available experimental data very well. The determined Franck-Condon factors and vibrational branching ratios of the A 2 Π 1 / 2 ( ν ' ) ← X 2 Σ1 / 2 + ( ν ) transition are highly diagonally distributed and the evaluated radiative lifetime for the A2Π1/2(ν' = 0) state is 28.2 ns, which is short enough for rapid laser cooling. Subsequently, detection of cold molecules via resonance enhanced multiphoton ionization to determine the final quantum state populations is discussed and the ionization energy calculated. A multi-pulse excitation scheme is proposed for producing ultracold chlorine atoms from zero-energy photodissociation of the cooled CaCl. Our results demonstrate the possibility of producing ultracold CaCl molecules and Cl atoms.

  18. Early Science with the Large Millimeter Telescope: COOL BUDHIES I - a pilot study of molecular and atomic gas at z ≃ 0.2

    Science.gov (United States)

    Cybulski, Ryan; Yun, Min S.; Erickson, Neal; De la Luz, Victor; Narayanan, Gopal; Montaña, Alfredo; Sánchez, David; Zavala, Jorge A.; Zeballos, Milagros; Chung, Aeree; Fernández, Ximena; van Gorkom, Jacqueline; Haines, Chris P.; Jaffé, Yara L.; Montero-Castaño, María; Poggianti, Bianca M.; Verheijen, Marc A. W.; Yoon, Hyein; Deshev, Boris Z.; Harrington, Kevin; Hughes, David H.; Morrison, Glenn E.; Schloerb, F. Peter; Velazquez, Miguel

    2016-07-01

    An understanding of the mass build-up in galaxies over time necessitates tracing the evolution of cold gas (molecular and atomic) in galaxies. To that end, we have conducted a pilot study called CO Observations with the LMT of the Blind Ultra-Deep H I Environment Survey (COOL BUDHIES). We have observed 23 galaxies in and around the two clusters Abell 2192 (z = 0.188) and Abell 963 (z = 0.206), where 12 are cluster members and 11 are slightly in the foreground or background, using about 28 total hours on the Redshift Search Receiver on the Large Millimeter Telescope (LMT) to measure the 12CO J = 1 → 0 emission line and obtain molecular gas masses. These new observations provide a unique opportunity to probe both the molecular and atomic components of galaxies as a function of environment beyond the local Universe. For our sample of 23 galaxies, nine have reliable detections (S/N ≥ 3.6) of the 12CO line, and another six have marginal detections (2.0 < S/N < 3.6). For the remaining eight targets we can place upper limits on molecular gas masses roughly between 109 and 1010 M⊙. Comparing our results to other studies of molecular gas, we find that our sample is significantly more abundant in molecular gas overall, when compared to the stellar and the atomic gas component, and our median molecular gas fraction lies about 1σ above the upper limits of proposed redshift evolution in earlier studies. We discuss possible reasons for this discrepancy, with the most likely conclusion being target selection and Eddington bias.

  19. Constraint Cooling of Hot Rolled Coil

    Institute of Scientific and Technical Information of China (English)

    WANG Li-juan; ZHANG Chun-li

    2004-01-01

    The layer thermal conductivity during constraint cooling of hot rolled coil was described by using equivalent thermal conductivity model and finite element method. Two radial stress concentration zones in constraint cooled coil were shown by numerical analysis, and the tension stress was assumed to be the main factor to induce stress corrosion. The experimental results show that the longer the water cooling time is, the smaller the grain size and the more uniform the grains are.

  20. Early Science with the Large Millimeter Telescope: COOL BUDHIES I - a pilot study of molecular and atomic gas at z~0.2

    CERN Document Server

    Cybulski, Ryan; Erickson, Neal; De la Luz, Victor; Narayanan, Gopal; Montaña, Alfredo; Sánchez-Argülles, David; Zavala, Jorge A; Zeballos, Milagros; Chung, Aeree; Fernández, Ximena; van Gorkom, Jacqueline; Haines, Chris P; Jaffé, Yara L; Montero-Castaño, María; Poggianti, Bianca M; Verheijen, Marc A W; Yoon, Hyein; Harrington, Kevin; Hughes, David H; Morrison, Glenn E; Schloerb, F Peter; Velazquez, Miguel

    2015-01-01

    An understanding of the mass build-up in galaxies over time necessitates tracing the evolution of cold gas (molecular and atomic) in galaxies. To that end, we have conducted a pilot study called CO Observations with the LMT of the Blind Ultra-Deep H I Environment Survey (COOL BUDHIES). We have observed 23 galaxies in and around the two clusters Abell 2192 (z = 0.188) and Abell 963 (z = 0.206), where 12 are cluster members and 11 are slightly in the foreground or background, using about 28 total hours on the Redshift Search Receiver (RSR) on the Large Millimeter Telescope (LMT) to measure the $^{12}$CO J = 1 --> 0 emission line and obtain molecular gas masses. These new observations provide a unique opportunity to probe both the molecular and atomic components of galaxies as a function of environment beyond the local Universe. For our sample of 23 galaxies, nine have reliable detections (S/N$\\geq$3.6) of the $^{12}$CO line, and another six have marginal detections (2.0 < S/N < 3.6). For the remaining eig...

  1. Validation of IRS PCR, a molecular typing method, for the study of the diversity and population dynamics of Legionella in industrial cooling circuits.

    Science.gov (United States)

    Jakubek, D; Le Brun, M; Leblon, G; Dubow, M; Binet, M

    2013-02-01

    Legionella bacteria are ubiquitous in aquatic environments. Members of the species Legionella pneumophila are responsible for more than 98% of cases of Legionnaires' disease in France. Our objective was to validate a molecular typing method called infrequent restriction site PCR (IRS PCR), applied to the study of the ecology of Legionella and to compare this method with reference typing methods, pulsed-field gel electrophoresis (PFGE) and sequence-based Typing (SBT). PFGE and SBT are considered as gold methods for the epidemiological typing of Leg. pneumophila strains. However, these methods are not suitable to an ecological monitoring of Legionella in natural environments where a large number of strains has to be typed. Validation of IRS PCR method was performed by the identification of 45 Leg. pneumophila isolates from cooling circuits of thermal power plants by IRS PCR, PFGE and SBT. The parameters of each method were measured and compared to evaluate the effectiveness of IRS PCR. The results of this study showed that IRS PCR has a discriminating power similar or better than that of the reference methods and thus that, by its speed and low cost represents an appropriate tool for the study of the ecology of Legionella in cooling circuits.

  2. Photoinduced intramolecular charge-transfer reactions in 4-amino-3-methyl benzoic acid methyl ester: A fluorescence study in condensedphase and jet-cooled molecular beams

    Indian Academy of Sciences (India)

    Amrita Chakraborty; Samiran Kar; D N Nath; Nikhil Guchhait

    2007-03-01

    Photoinduced intramolecular charge-transfer reactions in 4-amino-3-methyl benzoic acid methyl ester (AMBME) have been investigated spectroscopically. AMBME, with its weak charge donor primary amino group, shows dual emission in polar solvents. Absorption and emission measurements in the condensed phase support the premise that the short wavelength emission band corresponds to local emission and the long wavelength emission band to the charge transfer emission. Laser-induced fluorescence excitation spectra show the presence of two low-energy conformers in jet-cooled molecular beams. Theoretical calculations using density functional theory help to determine structure, vibrational modes, potential energy surface, transition energy and oscillator strength for correlating experimental findings with theoretical results.

  3. Molecular dynamics simulations of aqueous urea solutions: Study of dimer stability and solution structure, and calculation of the total nitrogen radial distribution function GN(r

    NARCIS (Netherlands)

    Boek, E.S.; Briels, W.J.

    1993-01-01

    Molecular dynamics simulations have been performed in order to study the structure of two molal urea solutions in D2O. Several initial dimer configurations were considered for an adequate sampling of phase space. Eventually all of them appeared to be unstable, when system size and periodic boundary

  4. [Approaches to radial shaft].

    Science.gov (United States)

    Bartoníček, J; Naňka, O; Tuček, M

    2015-10-01

    In the clinical practice, radial shaft may be exposed via two approaches, namely the posterolateral Thompson and volar (anterior) Henry approaches. A feared complication of both of them is the injury to the deep branch of the radial nerve. No consensus has been reached, yet, as to which of the two approaches is more beneficial for the proximal half of radius. According to our anatomical studies and clinical experience, Thompson approach is safe only in fractures of the middle and distal thirds of the radial shaft, but highly risky in fractures of its proximal third. Henry approach may be used in any fracture of the radial shaft and provides a safe exposure of the entire lateral and anterior surfaces of the radius.The Henry approach has three phases. In the first phase, incision is made along the line connecting the biceps brachii tendon and the styloid process of radius. Care must be taken not to damage the lateral cutaneous nerve of forearm.In the second phase, fascia is incised and the brachioradialis identified by the typical transition from the muscle belly to tendon and the shape of the tendon. On the lateral side, the brachioradialis lines the space with the radial artery and veins and the superficial branch of the radial nerve running at its bottom. On the medial side, the space is defined by the pronator teres in the proximal part and the flexor carpi radialis in the distal part. The superficial branch of the radial nerve is retracted together with the brachioradialis laterally, and the radial artery medially.In the third phase, the attachment of the pronator teres is identified by its typical tendon in the middle of convexity of the lateral surface of the radial shaft. The proximal half of the radius must be exposed very carefully in order not to damage the deep branch of the radial nerve. Dissection starts at the insertion of the pronator teres and proceeds proximally along its lateral border in interval between this muscle and insertion of the supinator

  5. Tracing cool molecular gas and star formation on $\\sim 100$pc scales within a $z=2.3$ galaxy

    CERN Document Server

    Thomson, A P; Owen, Frazer N; Danielson, A L R; Swinbank, A M; Smail, Ian

    2015-01-01

    We present new, high-angular resolution interferometric observations with the Karl G. Jansky Very Large Array of $^{12}$CO $J=1-0$ line emission and 4-8 GHz continuum emission in the strongly lensed, $z=2.3$ submillimetre galaxy, SMM J21352-0102. Using these data, we identify and probe the conditions in $\\sim 100$pc clumps within this galaxy, which we consider to be potential giant molecular cloud complexes, containing up to half of the total molecular gas in this system. In combination with far-infrared and submillimetre data, we investigate the far-infrared/radio correlation, measuring $q_{IR} = 2.39 \\pm 0.17$ across SMM J21352. We search for variations in the properties of the interstellar medium throughout the galaxy by measuring the spatially-resolved $q_{IR}$ and radio spectral index, ${\\alpha}_{\\rm radio}$, finding ranges $q_{IR} = [2.1, 2.6]$ and ${\\alpha}_{\\rm radio} = [-1.5, -0.7]$. We argue that these ranges in ${\\alpha}_{\\rm radio}$ and $q_{IR}$ may reflect variations in the age of the ISM materia...

  6. Radial spoke proteins of Chlamydomonas flagella

    Science.gov (United States)

    Yang, Pinfen; Diener, Dennis R.; Yang, Chun; Kohno, Takahiro; Pazour, Gregory J.; Dienes, Jennifer M.; Agrin, Nathan S.; King, Stephen M.; Sale, Winfield S.; Kamiya, Ritsu; Rosenbaum, Joel L.; Witman, George B.

    2007-01-01

    Summary The radial spoke is a ubiquitous component of ‘9+2’ cilia and flagella, and plays an essential role in the control of dynein arm activity by relaying signals from the central pair of microtubules to the arms. The Chlamydomonas reinhardtii radial spoke contains at least 23 proteins, only 8 of which have been characterized at the molecular level. Here, we use mass spectrometry to identify 10 additional radial spoke proteins. Many of the newly identified proteins in the spoke stalk are predicted to contain domains associated with signal transduction, including Ca2+-, AKAP- and nucleotide-binding domains. This suggests that the spoke stalk is both a scaffold for signaling molecules and itself a transducer of signals. Moreover, in addition to the recently described HSP40 family member, a second spoke stalk protein is predicted to be a molecular chaperone, implying that there is a sophisticated mechanism for the assembly of this large complex. Among the 18 spoke proteins identified to date, at least 12 have apparent homologs in humans, indicating that the radial spoke has been conserved throughout evolution. The human genes encoding these proteins are candidates for causing primary ciliary dyskinesia, a severe inherited disease involving missing or defective axonemal structures, including the radial spokes. PMID:16507594

  7. Danish Cool

    DEFF Research Database (Denmark)

    Toft, Anne Elisabeth

    2016-01-01

    Danish Cool. Keld Helmer-Petersen, Photography and the Photobook Handout exhibition text in English and Chinese by Anne Elisabeth Toft, Curator The exhibition Danish Cool. Keld Helmer-Petersen, Photography and the Photobook presents the ground-breaking work of late Danish photographer Keld Helmer...

  8. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  9. Molecular dynamics simulations of aqueous urea solutions: Study of dimer stability and solution structure, and calculation of the total nitrogen radial distribution function GN(r)

    Science.gov (United States)

    Boek, E. S.; Briels, W. J.

    1993-01-01

    Molecular dynamics simulations have been performed in order to study the structure of two molal urea solutions in D2O. Several initial dimer configurations were considered for an adequate sampling of phase space. Eventually all of them appeared to be unstable, when system size and periodic boundary conditions are chosen properly, even after a very careful equilibration. The total nitrogen scattering function GN(r), calculated from these simulations, is in good agreement with neutron scattering experiments when both intra- and intermolecular correlations are considered and the experimental truncation ripples are introduced by a Fourier transform of GN(r) back and forth. The simple pair potential model that we used gives results in good agreement with experiments and with a much more involved potential model, recently described in the literature [J. Chem. Phys. 95, 8419 (1991)].

  10. Quantum thermodynamic cooling cycle

    CERN Document Server

    Palao, J P; Gordon, J M; Palao, Jose P.; Kosloff, Ronnie; Gordon, Jeffrey M.

    2001-01-01

    The quantum-mechanical and thermodynamic properties of a 3-level molecular cooling cycle are derived. An inadequacy of earlier models is rectified in accounting for the spontaneous emission and absorption associated with the coupling to the coherent driving field via an environmental reservoir. This additional coupling need not be dissipative, and can provide a thermal driving force - the quantum analog of classical absorption chillers. The dependence of the maximum attainable cooling rate on temperature, at ultra-low temperatures, is determined and shown to respect the recently-established fundamental bound based on the second and third laws of thermodynamics.

  11. Simulations Of Laser Cooling In An Ultracold Neutral Plasma

    Science.gov (United States)

    Langin, Thomas; Strickler, Trevor; Pohl, Thomas; Vrinceanu, Daniel; Killian, Thomas

    2016-05-01

    Ultracold neutral plasmas (UNPs) generated by photoionization of laser-cooled, magneto-optically trapped neutral gases, are useful systems for studying strongly coupled plasmas. Coupling is parameterized by Γi, the ratio of the average nearest neighbor Coulomb interaction energy to the ion kinetic energy. For typical UNPs, Γi is currently limited to ~ 3 . For alkaline earth ions, higher Γi can be achieved by laser-cooling. Using Molecular Dynamics and a quantum trajectories approach, we have simulated laser-cooling of Sr+ ions interacting through a Yukawa potential. The simulations include re-pumping from two long-lived D-states, and are conducted at experimentally achievable parameters (density n = 2 e+14 m-3, size σ0 = 4 mm, Te = 19 K). Laser-cooling is shown to both reduce the temperature by a factor of 2 over relevant timescales (tens of μ s) and slow the electron thermal-pressure driven radial expansion of the UNP. We also discuss the unique aspects of laser-cooling in a highly collisional system; in particular, the effect of collisions on dark state formation due to the coupling of the P3/2 state to both the S1/2 (via the cooling transition) and the D5/2 (via a re-pump transition) states. Supported by NSF and DoE, the Air Force Office of Scientific Research, the NDSEG Program, and NIH NCRR S10RR02950, an IBM SUR Award in partnership with CISCO, Qlogic and Adaptive Computing.

  12. Radial Halbach Magnetic Bearings

    Science.gov (United States)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2009-01-01

    Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Radial Halbach magnetic bearings are based on the same principle as that of axial Halbach magnetic bearings, differing in geometry as the names of these two types of bearings suggest. Both radial and axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control. Axial Halbach magnetic bearings were described in Axial Halbach Magnetic Bearings (LEW-18066-1), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 85. In the remainder of this article, the description of the principle of operation from the cited prior article is recapitulated and updated to incorporate the present radial geometry. In simplest terms, the basic principle of levitation in an axial or radial Halbach magnetic bearing is that of the repulsive electromagnetic force between (1) a moving permanent magnet and (2) an electric current induced in a stationary electrical conductor by the motion of the magnetic field. An axial or radial Halbach bearing includes multiple permanent magnets arranged in a Halbach array ("Halbach array" is defined below) in a rotor and multiple conductors in the form of wire coils in a stator, all arranged so the rotary motion produces an axial or radial repulsion that is sufficient to levitate the rotor. A basic Halbach array (see Figure 1) consists of a row of permanent magnets, each oriented so that its magnetic field is at a right angle to that of the adjacent magnet, and the right-angle turns are sequenced so as to maximize the magnitude of the magnetic flux density on one side of the row while

  13. A Quick Study of the Characterization of Radial Velocity Giant Planets in Reflected Light by Forward and Inverse Modeling

    CERN Document Server

    Marley, Mark; Lewis, Nikole; Line, Michael; Morley, Caroline; Fortney, Jonathan

    2014-01-01

    We explored two aspects of the problem of characterizing cool extrasolar giant planets in scattered optical light with a space based coronagraph. First, for a number of the known radial velocity (RV) giants we computed traditional forward models of their atmospheric structure and clouds, given various input assumptions, and computed model albedo spectra. Such models have been computed before, but mostly for generic planets. Our new models demonstrate that there is likely interesting spectral diversity among those planets that are most favorable for direct detection. Second, we applied a powerful Markov Chain Monte Carlo (MCMC) retrieval technique to synthetic noisy data of cool giants to better understand how well various atmospheric parameters--particularly molecular abundances and cloud properties--could be constrained. This is the first time such techniques have been applied to this problem. The process is time consuming, so only a dozen or so cases could be completed in the limited time available. Neverth...

  14. Industrial stator vane with sequential impingement cooling inserts

    Science.gov (United States)

    Jones, Russell B; Fedock, John A; Goebel, Gloria E; Krueger, Judson J; Rawlings, Christopher K; Memmen, Robert L

    2013-08-06

    A turbine stator vane for an industrial engine, the vane having two impingement cooling inserts that produce a series of impingement cooling from the pressure side to the suction side of the vane walls. Each insert includes a spar with a row of alternating impingement cooling channels and return air channels extending in a radial direction. Impingement cooling plates cover the two sides of the insert and having rows of impingement cooling holes aligned with the impingement cooling channels and return air openings aligned with the return air channel.

  15. Low pressure cooling seal system for a gas turbine engine

    Science.gov (United States)

    Marra, John J

    2014-04-01

    A low pressure cooling system for a turbine engine for directing cooling fluids at low pressure, such as at ambient pressure, through at least one cooling fluid supply channel and into a cooling fluid mixing chamber positioned immediately downstream from a row of turbine blades extending radially outward from a rotor assembly to prevent ingestion of hot gases into internal aspects of the rotor assembly. The low pressure cooling system may also include at least one bleed channel that may extend through the rotor assembly and exhaust cooling fluids into the cooling fluid mixing chamber to seal a gap between rotational turbine blades and a downstream, stationary turbine component. Use of ambient pressure cooling fluids by the low pressure cooling system results in tremendous efficiencies by eliminating the need for pressurized cooling fluids for sealing this gap.

  16. Improved Lattice Radial Quantization

    CERN Document Server

    Brower, Richard C; Fleming, George T

    2014-01-01

    Lattice radial quantization was proposed in a recent paper by Brower, Fleming and Neuberger[1] as a nonperturbative method especially suited to numerically solve Euclidean conformal field theories. The lessons learned from the lattice radial quantization of the 3D Ising model on a longitudinal cylinder with 2D Icosahedral cross-section suggested the need for an improved discretization. We consider here the use of the Finite Element Methods(FEM) to descretize the universally-equivalent $\\phi^4$ Lagrangian on $\\mathbb R \\times \\mathbb S^2$. It is argued that this lattice regularization will approach the exact conformal theory at the Wilson-Fisher fixed point in the continuum. Numerical tests are underway to support this conjecture.

  17. The ARCS radial collimator

    OpenAIRE

    Stone M.B.; Niedziela J.L.; Overbay M.A.; Abernathy D.L.

    2015-01-01

    We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. W...

  18. Perceived radial translation during centrifugation

    NARCIS (Netherlands)

    Bos, J.E.; Correia Grácio, B.J.

    2015-01-01

    BACKGROUND: Linear acceleration generally gives rise to translation perception. Centripetal acceleration during centrifugation, however, has never been reported giving rise to a radial, inward translation perception. OBJECTIVE: To study whether centrifugation can induce a radial translation percepti

  19. Antiproton compression and radial measurements

    Science.gov (United States)

    Andresen, G. B.; Bertsche, W.; Bowe, P. D.; Bray, C. C.; Butler, E.; Cesar, C. L.; Chapman, S.; Charlton, M.; Fajans, J.; Fujiwara, M. C.; Funakoshi, R.; Gill, D. R.; Hangst, J. S.; Hardy, W. N.; Hayano, R. S.; Hayden, M. E.; Humphries, A. J.; Hydomako, R.; Jenkins, M. J.; Jørgensen, L. V.; Kurchaninov, L.; Lambo, R.; Madsen, N.; Nolan, P.; Olchanski, K.; Olin, A.; Page, R. D.; Povilus, A.; Pusa, P.; Robicheaux, F.; Sarid, E.; El Nasr, S. Seif; Silveira, D. M.; Storey, J. W.; Thompson, R. I.; van der Werf, D. P.; Wurtele, J. S.; Yamazaki, Y.

    2008-08-01

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  20. Ventilative Cooling

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols; Kolokotroni, Maria

    This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state-of-the-art of ventil......This report, by venticool, summarises the outcome of the work of the initial working phase of IEA ECB Annex 62 Ventilative Cooling and is based on the findings in the participating countries. It presents a summary of the first official Annex 62 report that describes the state...

  1. Organization of polymer chains onto long, single-wall carbon nano-tubes: effect of tube diameter and cooling method.

    Science.gov (United States)

    Kumar, Sunil; Pattanayek, Sudip K; Pereira, Gerald G

    2014-01-14

    We use molecular dynamics simulations to investigate the arrangement of polymer chains when absorbed onto a long, single-wall carbon nano-tube (SWCNT). We study the conformation and organization of the polymer chains on the SWCNT and their dependence on the tube's diameter and the rate of cooling. We use two types of cooling processes: direct quenching and gradual cooling. The radial density distribution function and bond orientational order parameter are used to characterize the polymer chain structure near the surface. In the direct cooling process, the beads of the polymer chain organize in lamella-like patterns on the surface of the SWCNT with the long axis of the lamella parallel to the axis of the SWCNT. In a stepwise, gradual cooling process, the polymer beads form a helical pattern on the surface of a relatively thick SWCNT, but form a lamella-like pattern on the surface of a very thin SWCNT. We develop a theoretical (free energy) model to explain this difference in pattern structures for the gradual cooling process and also provide a qualitative explanation for the pattern that forms from the direct cooling process.

  2. Star Formation in the Galactic Center: Radial Cloud Orbits via Feedback and Radiative Losses

    Science.gov (United States)

    Frazer, Chris; Heitsch, Fabian

    2015-01-01

    Simulations of misaligned gas streamers in the vicinity of supermassive black holes indicate that highly radial molecular flows are marked precursors of star formation in the Galactic Center (GC), yet the manner by which cold gas can adopt such orbits remains unclear. Through hydrodynamic models of the circumnuclear disk (CND), we investigate the development of such trajectories due to catastrophic angular momentum redistribution driven by stellar feedback (supernovae). For an improved equation of state, a prescription for optically thin cooling is included and heating arising from black hole X-ray radiation, interstellar radiation fields, and cosmic ray ionization is used in agreement with dust and gas measurements of the GC. Compared to adiabatic simulations, models with full thermal physics show density enhancements of a few orders of magnitude. Furthermore, the filaments forming in these simulations are characterized by lower angular momentum orbits. Combined, these effects suggest that fragmentation of the CND can provide an avenue for the development of highly radial molecular gas in-fall and the subsequent formation of stars.

  3. Cool snacks

    DEFF Research Database (Denmark)

    Grunert, Klaus G; Brock, Steen; Brunsø, Karen

    2016-01-01

    such a product requires an interdisciplinary effort where researchers with backgrounds in psychology, anthropology, media science, philosophy, sensory science and food science join forces. We present the COOL SNACKS project, where such a blend of competences was used first to obtain thorough insight into young...

  4. The ARCS radial collimator

    Directory of Open Access Journals (Sweden)

    Stone M.B.

    2015-01-01

    Full Text Available We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. We present here characterization of the collimator's performance and methodologies for its effective use.

  5. The ARCS radial collimator

    Science.gov (United States)

    Stone, M. B.; Niedziela, J. L.; Overbay, M. A.; Abernathy, D. L.

    2015-01-01

    We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. We present here characterization of the collimator's performance and methodologies for its effective use.

  6. Radial reflection diffraction tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, Sean K.

    2012-12-18

    A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

  7. Radial Reflection diffraction tomorgraphy

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, Sean K

    2013-11-19

    A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

  8. Stochastic cooling

    Energy Technology Data Exchange (ETDEWEB)

    Bisognano, J.; Leemann, C.

    1982-03-01

    Stochastic cooling is the damping of betatron oscillations and momentum spread of a particle beam by a feedback system. In its simplest form, a pickup electrode detects the transverse positions or momenta of particles in a storage ring, and the signal produced is amplified and applied downstream to a kicker. The time delay of the cable and electronics is designed to match the transit time of particles along the arc of the storage ring between the pickup and kicker so that an individual particle receives the amplified version of the signal it produced at the pick-up. If there were only a single particle in the ring, it is obvious that betatron oscillations and momentum offset could be damped. However, in addition to its own signal, a particle receives signals from other beam particles. In the limit of an infinite number of particles, no damping could be achieved; we have Liouville's theorem with constant density of the phase space fluid. For a finite, albeit large number of particles, there remains a residue of the single particle damping which is of practical use in accumulating low phase space density beams of particles such as antiprotons. It was the realization of this fact that led to the invention of stochastic cooling by S. van der Meer in 1968. Since its conception, stochastic cooling has been the subject of much theoretical and experimental work. The earliest experiments were performed at the ISR in 1974, with the subsequent ICE studies firmly establishing the stochastic cooling technique. This work directly led to the design and construction of the Antiproton Accumulator at CERN and the beginnings of p anti p colliding beam physics at the SPS. Experiments in stochastic cooling have been performed at Fermilab in collaboration with LBL, and a design is currently under development for a anti p accumulator for the Tevatron.

  9. Radial Velocities with PARAS

    Science.gov (United States)

    Roy, Arpita; Mahadevan, S.; Chakraborty, A.; Pathan, F. M.; Anandarao, B. G.

    2010-01-01

    The Physical Research Laboratory Advanced Radial-velocity All-sky Search (PARAS) is an efficient fiber-fed cross-dispersed high-resolution echelle spectrograph that will see first light in early 2010. This instrument is being built at the Physical Research laboratory (PRL) and will be attached to the 1.2m telescope at Gurushikhar Observatory at Mt. Abu, India. PARAS has a single-shot wavelength coverage of 370nm to 850nm at a spectral resolution of R 70000 and will be housed in a vacuum chamber (at 1x10-2 mbar pressure) in a highly temperature controlled environment. This renders the spectrograph extremely suitable for exoplanet searches with high velocity precision using the simultaneous Thorium-Argon wavelength calibration method. We are in the process of developing an automated data analysis pipeline for echelle data reduction and precise radial velocity extraction based on the REDUCE package of Piskunov & Valenti (2002), which is especially careful in dealing with CCD defects, extraneous noise, and cosmic ray spikes. Here we discuss the current status of the PARAS project and details and tests of the data analysis procedure, as well as results from ongoing PARAS commissioning activities.

  10. A very cool cooling system

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    The NA62 Gigatracker is a jewel of technology: its sensor, which delivers the time of the crossing particles with a precision of less than 200 picoseconds (better than similar LHC detectors), has a cooling system that might become the precursor to a completely new detector technique.   The 115 metre long vacuum tank of the NA62 experiment. The NA62 Gigatracker (GTK) is composed of a set of three innovative silicon pixel detectors, whose job is to measure the arrival time and the position of the incoming beam particles. Installed in the heart of the NA62 detector, the silicon sensors are cooled down (to about -20 degrees Celsius) by a microfluidic silicon device. “The cooling system is needed to remove the heat produced by the readout chips the silicon sensor is bonded to,” explains Alessandro Mapelli, microsystems engineer working in the Physics department. “For the NA62 Gigatracker we have designed a cooling plate on top of which both the silicon sensor and the...

  11. Starspot-induced radial velocity jitter during a stellar cycle

    DEFF Research Database (Denmark)

    Korhonen, Heidi Helena; Andersen, Jan Marie; Järvinen, Silva

    2012-01-01

    on the Sun and other cool stars changes cyclically during an activity cycle, which has length varying from about a year to longer than the solar 11 years. In this work we investigate the influence of varying amount of starspots on the sparsely sampled radial velocity observations - which are the norm...... in the radial velocity studies searching for exoplanets on wide orbits. We study two simulated cases: one with a random spot configuration, and one where the spot occurrence is concentrated. In addition we use Doppler images of young solar analogue V889 Her as a high activity case....

  12. Cooling technique

    Energy Technology Data Exchange (ETDEWEB)

    Salamon, Todd R; Vyas, Brijesh; Kota, Krishna; Simon, Elina

    2017-01-31

    An apparatus and a method are provided. Use is made of a wick structure configured to receive a liquid and generate vapor in when such wick structure is heated by heat transferred from heat sources to be cooled off. A vapor channel is provided configured to receive the vapor generated and direct said vapor away from the wick structure. In some embodiments, heat conductors are used to transfer the heat from the heat sources to the liquid in the wick structure.

  13. Radial Reflection Diffraction Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, S K; Norton, S J

    2003-10-10

    We develop a wave-based tomographic imaging algorithm based upon a single rotating radially outward oriented transducer. At successive angular locations at a fixed radius, the transducer launches a primary field and collects the backscattered field in a ''pitch/catch'' operation. The hardware configuration, operating mode, and data collection method is identical to that of most medical intravascular ultrasound (IVUS) systems. IVUS systems form images of the medium surrounding the probe based upon ultrasonic B-scans, using a straight-ray model of sound propagation. Our goal is to develop a wave-based imaging algorithm using diffraction tomography techniques. Given the hardware configuration and the imaging method, we refer to this system as ''radial reflection diffraction tomography.'' We consider two hardware configurations: a multimonostatic mode using a single transducer as described above, and a multistatic mode consisting of a single transmitter and an aperture formed by multiple receivers. In this latter case, the entire source/receiver aperture rotates about the fixed radius. Practically, such a probe is mounted at the end of a catheter or snaking tube that can be inserted into a part or medium with the goal of forming images of the plane perpendicular to the axis of rotation. We derive an analytic expression for the multimonostatic inverse but ultimately use the new Hilbert space inverse wave (HSIW) algorithm to construct images using both operating modes. Applications include improved IVUS imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts with existing access holes.

  14. Radial system of dark globules in Ser OB2

    Science.gov (United States)

    Gyulbudaghian, A. L.

    2012-09-01

    A radial system illuminated by bright, central OB stars is discussed. 12CO(1-0) observations are made of three globules from this system. Three molecular clouds are detected which are dark globules of a radial system in Ser OB2. A group of IR stars near the boundary of a globule with a rim is studied. One of the IR stars with bright filaments is a YSO (young stellar object). The radial system contains two bright, Mshaped fronts located at the tip of a jet, which may have emerged from the Wolf-Rayet star WR113. Similar M-shaped fronts are also located near the object SNO 85.

  15. Antiproton compression and radial measurements

    CERN Document Server

    Andresen, G B; Bowe, P D; Bray, C C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jenkins, M J; Jorgensen, L V; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Page R D; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; Van der Werf, D P; Wurtele, J S; Yamazaki, Y

    2008-01-01

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  16. Evolution of molecular clouds

    Science.gov (United States)

    Sevenster, M.

    1993-01-01

    The evolution of interstellar molecular hydrogen was studied, with a special interest for the formation and evolution of molecular clouds and star formation within them, by a two-dimensional hydrodynamical simulation performed on a rectangular grid of physical sizes on the order of 100 pc. It is filled with an initial density of approx. 1 cm(exp -3), except for one cell (approx. 1 pc(exp 2)) at the center of the grid where an accretion core of 1-10(exp 3) solar masses is placed. The grid is co-moving with the gridcenter that is on a circular orbit around the Galactic center and that also is the guiding center of epicyclic approximation of orbits of the matter surrounding it. The initial radial velocity is zero; to account for differential rotation the initial tangential velocity (i.e. the movement around the galactic center) is proportional to the radial distance to the grid center. The rate is comparable to the rotation rate at the Local Standard of Rest. The influence of galactic rotation is noticed by spiral or elliptical forms, but on much longer time scales than self gravitation and cooling processes. Density and temperature are kept constant at the boundaries and no inflow is allowed along the tangential boundaries.

  17. ATLAS - Liquid Cooling Systems

    CERN Multimedia

    Bonneau, P.

    1998-01-01

    Photo 1 - Cooling Unit - Side View Photo 2 - Cooling Unit - Detail Manifolds Photo 3 - Cooling Unit - Rear View Photo 4 - Cooling Unit - Detail Pump, Heater and Exchanger Photo 5 - Cooling Unit - Detail Pump and Fridge Photo 6 - Cooling Unit - Front View

  18. Turbine with radial acting seal

    Energy Technology Data Exchange (ETDEWEB)

    Eng, Darryl S; Ebert, Todd A

    2016-11-22

    A floating brush seal in a rim cavity of a turbine in a gas turbine engine, where the floating brush seal includes a seal holder in which the floating brush seal floats, and a expandable seal that fits within two radial extending seal slots that maintains a seal with radial displacement of the floating brush seal and the seal holder.

  19. Radial gas turbine design

    Energy Technology Data Exchange (ETDEWEB)

    Krausche, S.; Ohlsson, Johan

    1998-04-01

    The objective of this work was to develop a program dealing with design point calculations of radial turbine machinery, including both compressor and turbine, with as few input data as possible. Some simple stress calculations and turbine metal blade temperatures were also included. This program was then implanted in a German thermodynamics program, Gasturb, a program calculating design and off-design performance of gas turbines. The calculations proceed with a lot of assumptions, necessary to finish the task, concerning pressure losses, velocity distribution, blockage, etc., and have been correlated with empirical data from VAT. Most of these values could have been input data, but to prevent the user of the program from drowning in input values, they are set as default values in the program code. The output data consist of geometry, Mach numbers, predicted component efficiency etc., and a number of graphical plots of geometry and velocity triangles. For the cases examined, the error in predicted efficiency level was within {+-} 1-2% points, and quite satisfactory errors in geometrical and thermodynamic conditions were obtained Examination paper. 18 refs, 36 figs

  20. High precision radial velocities with GIANO spectra

    CERN Document Server

    Carleo, I; Gratton, R; Benatti, S; Bonavita, M; Oliva, E; Origlia, L; Desidera, S; Claudi, R; Sissa, E

    2016-01-01

    Radial velocities (RV) measured from near-infrared (NIR) spectra are a potentially excellent tool to search for extrasolar planets around cool or active stars. High resolution infrared (IR) spectrographs now available are reaching the high precision of visible instruments, with a constant improvement over time. GIANO is an infrared echelle spectrograph at the Telescopio Nazionale Galileo (TNG) and it is a powerful tool to provide high resolution spectra for accurate RV measurements of exoplanets and for chemical and dynamical studies of stellar or extragalactic objects. No other high spectral resolution IR instrument has GIANO's capability to cover the entire NIR wavelength range (0.95-2.45 micron) in a single exposure. In this paper we describe the ensemble of procedures that we have developed to measure high precision RVs on GIANO spectra acquired during the Science Verification (SV) run, using the telluric lines as wavelength reference. We used the Cross Correlation Function (CCF) method to determine the v...

  1. Cool visitors

    CERN Multimedia

    2006-01-01

    Pictured, from left to right: Tim Izo (saxophone, flute, guitar), Bobby Grant (tour manager), George Pajon (guitar). What do the LHC and a world-famous hip-hop group have in common? They are cool! On Saturday, 1st July, before their appearance at the Montreux Jazz Festival, three members of the 'Black Eyed Peas' came on a surprise visit to CERN, inspired by Dan Brown's Angels and Demons. At short notice, Connie Potter (Head of the ATLAS secretariat) organized a guided tour of ATLAS and the AD 'antimatter factory'. Still curious, lead vocalist Will.I.Am met CERN physicist Rolf Landua after the concert to ask many more questions on particles, CERN, and the origin of the Universe.

  2. Dropwise Condensation on a Radial Gradient Surface

    Science.gov (United States)

    Macner, Ashley; Daniel, Susan; Steen, Paul

    2013-11-01

    In transient dropwise condensation from steam onto a cool surface, distributions of drops evolve by nucleation, growth, and coalescence. This study examines how surface functionalization affects drop growth and coalescence. Surfaces are treated by silanization to deliver either a spatially uniform contact-angle (hydrophilic, neutral, and hydrophobic) or a radial gradient of contact-angles. The time evolution of number-density and associated drop-size distributions are reported. For a typical condensation experiment on a uniform angle surface, the number-density curves show two regimes: an initial increase in number-density as a result of nucleation and a subsequent decrease in number-density as a result of larger scale coalescence events. Without a removal mechanism, the fractional coverage, regardless of treatment, approaches unity. For the same angle-surface, the associated drop-size distributions progress through four different shapes along the growth curve. In contrast, for a radial gradient surface where removal by sweeping occurs, the number-density increases and then levels off to a value close to the maximum number-density that is well below unity coverage and only two shapes of distributions are observed. Implications for heat transfer will be discussed. This work was supported by a NASA Office of the Chief Technologist's Space Technology Research Fellowship.

  3. Vibrational Spectroscopy of Laser Cooled CaH

    Science.gov (United States)

    2015-10-28

    Molecular ions trapped in RF Paul traps and sympathetically- cooled with laser - cooled atomic ions have been shown to be a great platform to measure...Approved for public release; distribution is unlimited. Vibrational Spectroscopy of Laser Cooled CaH+ The views, opinions and/or findings contained in...Angeles, CA 90095 -1406 ABSTRACT Vibrational Spectroscopy of Laser Cooled CaH+ Report Title Cold molecules and molecular ions are leading to a renaissance

  4. High-Altitude Flight Cooling Investigation of a Radial Air-Cooled Engine

    Science.gov (United States)

    1946-08-01

    The charge-air weight flow was measured during flight by venturi meters installed in the two parallel lines between tileintercooler and car?nmetor...pressure was measured by a shrouded total-head tubo installed on a streamline loom on the right wi~ tip. A swiveling static tube, which was calibrated in a

  5. The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands

    Directory of Open Access Journals (Sweden)

    G. D. Wells

    Full Text Available In the past the global, fully coupled, time-dependent mathematical model of the Earth's thermosphere/ionosphere/plasmasphere (CTIP has been unable to reproduce accurately observed values of the maximum plasma frequency, foF2, at extreme geophysical locations such as the Argentine Islands during the summer solstice where the ionosphere remains in sunlight throughout the day. This is probably because the seasonal dependence of thermospheric cooling by 5.3 µm nitric oxide has been neglected and the photodissociation of O2 and heating rate calculations have been over-simplified. Now we have included an up-to-date calculation of the solar EUV and UV thermospheric heating rate, coupled with a new calculation of a diurnally varying O2 photodissociation rate, in the model. Seasonally dependent 5.3 µm nitric oxide cooling is also included. With these important improvements, it is found that model values of foF2 are in substantially better agreement with observation. The height of the F2-peak is reduced throughout the day, but remains within acceptable limits of values derived from observation, except at around 0600 h LT. We also carry out two studies of the sensitivity of the upper atmosphere to changes in the magnitude of nitric oxide cooling and photodissociation rates. We find that hmF2 increases with increased heating, whilst foF2 falls. The converse is true for an increase in the cooling rate. Similarly increasing the photodissociation rate increases both hmF2 and foF2. These changes are explained in terms of changes in the neutral temperature, composition and neutral wind.

  6. Lattice radial quantization by cubature

    CERN Document Server

    Neuberger, Herbert

    2014-01-01

    Basic aspects of a program to put field theories quantized in radial coordinates on the lattice are presented. Only scalar fields are discussed. Simple examples are solved to illustrate the strategy when applied to the 3D Ising model.

  7. Dedicated radial ventriculography pigtail catheter

    Energy Technology Data Exchange (ETDEWEB)

    Vidovich, Mladen I., E-mail: miv@uic.edu

    2013-05-15

    A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The “short” dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The “long” dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

  8. Thin-Film Evaporative Cooling for Side-Pumped Laser

    Science.gov (United States)

    Stewart, Brian K. (Inventor)

    2010-01-01

    A system and method are provided for cooling a crystal rod of a side-pumped laser. A transparent housing receives the crystal rod therethrough so that an annular gap is defined between the housing and the radial surface of the crystal rod. A fluid coolant is injected into the annular gap such the annular gap is partially filled with the fluid coolant while the radial surface of the crystal rod is wetted as a thin film all along the axial length thereof.

  9. Radial head dislocation during proximal radial shaft osteotomy.

    Science.gov (United States)

    Hazel, Antony; Bindra, Randy R

    2014-03-01

    The following case report describes a 48-year-old female patient with a longstanding both-bone forearm malunion, who underwent osteotomies of both the radius and ulna to improve symptoms of pain and lack of rotation at the wrist. The osteotomies were templated preoperatively. During surgery, after performing the planned radial shaft osteotomy, the authors recognized that the radial head was subluxated. The osteotomy was then revised from an opening wedge to a closing wedge with improvement of alignment and rotation. The case report discusses the details of the operation, as well as ways in which to avoid similar shortcomings in the future.

  10. Radial lean direct injection burner

    Science.gov (United States)

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  11. Radial propagators and Wilson loops

    CERN Document Server

    Leupold, S; Leupold, Stefan; Weigert, Heribert

    1996-01-01

    We present a relation which connects the propagator in the radial (Fock-Schwinger) gauge with a gauge invariant Wilson loop. It is closely related to the well-known field strength formula and can be used to calculate the radial gauge propagator. The result is shown to diverge in four-dimensional space even for free fields, its singular nature is however naturally explained using the renormalization properties of Wilson loops with cusps and self-intersections. Using this observation we provide a consistent regularization scheme to facilitate loop calculations. Finally we compare our results with previous approaches to derive a propagator in Fock-Schwinger gauge.

  12. Detonation in supersonic radial outflow

    KAUST Repository

    Kasimov, Aslan R.

    2014-11-07

    We report on the structure and dynamics of gaseous detonation stabilized in a supersonic flow emanating radially from a central source. The steady-state solutions are computed and their range of existence is investigated. Two-dimensional simulations are carried out in order to explore the stability of the steady-state solutions. It is found that both collapsing and expanding two-dimensional cellular detonations exist. The latter can be stabilized by putting several rigid obstacles in the flow downstream of the steady-state sonic locus. The problem of initiation of standing detonation stabilized in the radial flow is also investigated numerically. © 2014 Cambridge University Press.

  13. CONGENITAL RADIAL DYSPLASIA: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Venkatram Reddy

    2015-08-01

    Full Text Available Congenital radial dysplasia, also referred to as radial club hand , means deficiency along the preaxial or radial side of the extremity. It ranges from hypoplasia of the thumb to variou s degrees of radial hypoplasia. We present one such rare case of type 4 congenital unilateral isolated radial dysplasia with carpel anomaly , reported to our department in SVS medical C ollege, Mahabubanagar, Telangana state

  14. Solidification zoning and metallographic cooling rates of chondrites

    Science.gov (United States)

    Willis, J.; Goldstein, J. I.

    1981-01-01

    The cooling rates of chondrites have been determined according to the cooling rate method of Wood (1967) which involves the measurement of the concentration of nickel in the interiors of taenite grains of various sizes. The present paper presents an investigation of the effect of zoning produced during solidification on the use of the Wood method. Cooling rate curves were obtained in a computer simulation based on a model of kamacite formation on the outer edge of a taenite sphere of uniform initial composition, followed by the inward radial progression of the kamacite-taenite interface. When a concentration gradient produced by solidification is present in the initial conditions, deviations from the cooling rate curves for uniform 10% Ni are obtained only at cooling rates greater than 1000 K/million years, which would result in an overestimation of the cooling rates based on observed Ni gradients in grains of radius greater than 20 microns.

  15. EIT ground-state cooling of long ion strings

    CERN Document Server

    Lechner, R; Hempel, C; Jurcevic, P; Lanyon, B P; Monz, T; Brownnutt, M; Blatt, R; Roos, C F

    2016-01-01

    Electromagnetically-induced-transparency (EIT) cooling is a ground-state cooling technique for trapped particles. EIT offers a broader cooling range in frequency space compared to more established methods. In this work, we experimentally investigate EIT cooling in strings of trapped atomic ions. In strings of up to 18 ions, we demonstrate simultaneous ground state cooling of all radial modes in under 1 ms. This is a particularly important capability in view of emerging quantum simulation experiments with large numbers of trapped ions. Our analysis of the EIT cooling dynamics is based on a novel technique enabling single-shot measurements of phonon numbers, by rapid adiabatic passage on a vibrational sideband of a narrow transition.

  16. Hybrid radiator cooling system

    Science.gov (United States)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  17. Oxygen Absorption in Cooling Flows.

    Science.gov (United States)

    Buote

    2000-04-01

    The inhomogeneous cooling flow scenario predicts the existence of large quantities of gas in massive elliptical galaxies, groups, and clusters that have cooled and dropped out of the flow. Using spatially resolved, deprojected X-ray spectra from the ROSAT PSPC, we have detected strong absorption over energies approximately 0.4-0.8 keV intrinsic to the central approximately 1&arcmin; of the galaxy NGC 1399, the group NGC 5044, and the cluster A1795. These systems have among the largest nearby cooling flows in their respective classes and low Galactic columns. Since no excess absorption is indicated for energies below approximately 0.4 keV, the most reasonable model for the absorber is warm, collisionally ionized gas with T=105-106 K in which ionized states of oxygen provide most of the absorption. Attributing the absorption only to ionized gas reconciles the large columns of cold H and He inferred from Einstein and ASCA with the lack of such columns inferred from ROSAT and also is consistent with the negligible atomic and molecular H inferred from H i and CO observations of cooling flows. The prediction of warm ionized gas as the product of mass dropout in these and other cooling flows can be verified by Chandra and X-Ray Multimirror Mission.

  18. Tachoastrometry: astrometry with radial velocities

    CERN Document Server

    Pasquini, L; Lombardi, M; Monaco, L; Leão, I C; Delabre, B

    2014-01-01

    Spectra of composite systems (e.g., spectroscopic binaries) contain spatial information that can be retrieved by measuring the radial velocities (i.e., Doppler shifts) of the components in four observations with the slit rotated by 90 degrees in the sky. By using basic concepts of slit spectroscopy we show that the geometry of composite systems can be reliably retrieved by measuring only radial velocity differences taken with different slit angles. The spatial resolution is determined by the precision with which differential radial velocities can be measured. We use the UVES spectrograph at the VLT to observe the known spectroscopic binary star HD 188088 (HIP 97944), which has a maximum expected separation of 23 milli-arcseconds. We measure an astrometric signal in radial velocity of 276 \\ms, which corresponds to a separation between the two components at the time of the observations of 18 $\\pm2$ milli-arcseconds. The stars were aligned east-west. We describe a simple optical device to simultaneously record p...

  19. High-Temperature, High-Load-Capacity Radial Magnetic Bearing

    Science.gov (United States)

    Provenza, Andrew; Montague, Gerald; Kascak, Albert; Palazzolo, Alan; Jansen, Ralph; Jansen, Mark; Ebihara, Ben

    2005-01-01

    A radial heteropolar magnetic bearing capable of operating at a temperature as high as 1,000 F (=540 C) has been developed. This is a prototype of bearings for use in gas turbine engines operating at temperatures and speeds much higher than can be withstood by lubricated rolling-element bearings. It is possible to increase the maximum allowable operating temperatures and speeds of rolling-element bearings by use of cooling-air systems, sophisticated lubrication systems, and rotor-vibration- damping systems that are subsystems of the lubrication systems, but such systems and subsystems are troublesome. In contrast, a properly designed radial magnetic bearing can suspend a rotor without contact, and, hence, without need for lubrication or for cooling. Moreover, a magnetic bearing eliminates the need for a separate damping system, inasmuch as a damping function is typically an integral part of the design of the control system of a magnetic bearing. The present high-temperature radial heteropolar magnetic bearing has a unique combination of four features that contribute to its suitability for the intended application: 1. The wires in its electromagnet coils are covered with an insulating material that does not undergo dielectric breakdown at high temperature and is pliable enough to enable the winding of the wires to small radii. 2. The processes used in winding and potting of the coils yields a packing factor close to 0.7 . a relatively high value that helps in maximizing the magnetic fields generated by the coils for a given supplied current. These processes also make the coils structurally robust. 3. The electromagnets are of a modular C-core design that enables replacement of components and semiautomated winding of coils. 4. The stator is mounted in such a manner as to provide stable support under radial and axial thermal expansion and under a load as large as 1,000 lb (.4.4 kN).

  20. Competition between inter- and intra-molecular hydrogen bonding: An infrared spectroscopic study of jet-cooled amino-ethanol and its dimer

    Science.gov (United States)

    Asselin, Pierre; Madebène, Bruno; Soulard, Pascale; Georges, Robert; Goubet, Manuel; Huet, Thérèse R.; Pirali, Olivier; Zehnacker-Rentien, Anne

    2016-12-01

    The Fourier transform IR vibrational spectra of amino-ethanol (AE) and its dimer have been recorded at room temperature and under jet-cooled conditions over the far and mid infrared ranges (50-4000 cm-1) using the White-type cell and the supersonic jet of the Jet-AILES apparatus at the synchrotron facility SOLEIL. Assignment of the monomer experimental frequencies has been derived from anharmonic frequencies calculated at a hybrid CCSD(T)-F12/MP2 level. Various thermodynamical effects in the supersonic expansion conditions including molar dilution of AE and nature of carrier gas have been used to promote or not the formation of dimers. Four vibrational modes of the observed dimer have been unambiguously assigned using mode-specific scaling factors deduced from the ratio between experimental and computed frequencies for the monomer. The most stable g'Gg' monomer undergoes strong deformation upon dimerization, leading to a homochiral head to head dimer involving two strong hydrogen bonds.

  1. Severity grading in radial dysplasia.

    Science.gov (United States)

    Vilkki, S K

    2014-11-01

    A functional scoring method to grade the usefulness and quality of the upper limbs in congenital radial dysplasia is presented. It is based on the author's examinations of 44 arms with congenital deficiency of the radius. The hand (H), wrist (W) and proximal parts (P) of the extremity are each scored from 0 to 10 points for severity. The scoring is expressed similarly to the TNM (tumour, nodes, metastasis) tumour classification, for example as H5W4P2. The maximum severity index is 30 points. A severity grade of mild is between 1 and 8 points, moderate between 9 and 16 points and severe 17 points and over. In the author's series, the grades were mild in eight, moderate in 21 and severe in 15 cases. The functional severity grading should allow better comparison of radially deficient limbs and the results of treatment between groups of patients. © The Author(s) 2014.

  2. Velocidades radiales en Collinder 121

    Science.gov (United States)

    Arnal, M.; Morrell, N.

    Se han llevado a cabo observaciones espectroscópicas de unas treinta estrellas que son posibles miembros del cúmulo abierto Collinder 121. Las mismas fueron realizadas con el telescopio de 2.15m del Complejo Astronómico El Leoncito (CASLEO). El análisis de las velocidades radiales derivadas del material obtenido, confirma la realidad de Collinder 121, al menos desde el punto de vista cinemático. La velocidad radial baricentral (LSR) del cúmulo es de +17 ± 3 km.s-1. Esta velocidad coincide, dentro de los errores, con la velocidad radial (LSR) de la nebulosa anillo S308, la cual es de ~20 ± 10 km.s-1. Como S308 se encuentra físicamente asociada a la estrella Wolf-Rayet HD~50896, es muy probable que esta última sea un miembro de Collinder 121. Desde un punto de vista cinemático, la supergigante roja HD~50877 (K3Iab) también pertenecería a Collinder 121. Basándonos en la pertenencia de HD~50896 a Collinder 121, y en la interacción encontrada entre el viento de esta estrella y el medio interestelar circundante a la misma, se estima para este cúmulo una distancia del orden de 1 kpc.

  3. Liquid-Cooled Garment

    Science.gov (United States)

    1977-01-01

    A liquid-cooled bra, offshoot of Apollo moon suit technology, aids the cancer-detection technique known as infrared thermography. Water flowing through tubes in the bra cools the skin surface to improve resolution of thermograph image.

  4. Cooling system in a rotary piston internal combustion engine. Kuehlsystem einer Rotationskolbenbrennkraftmaschine

    Energy Technology Data Exchange (ETDEWEB)

    Eiermann, D.; Nuber, R.

    1991-05-23

    Cooling system of a trochoid-type rotary piston internal combustion engine with a liquid-cooled casing. First the coolant is conducted isochronically and in parallel through cooling chambers of the jacket and a side part of the casing from where it is transported by a cooling pump through the cooling chambers of the other side part, on past a thermostat and into a cooler positioned on this other side part. The cooler consists of a parallel connected pipe bundle whose finned pipes follow the radial outer contours of the casing of the machine. From the cooler the coolant is conducted back into the cooling chambers of the first side part and the jacket. A blower fitted on the eccentric shaft of the internal combustion engine inside the cooler takes in fresh air axially and discharges it radially through the finned pipes.

  5. Data center cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J; Dang, Hien P; Parida, Pritish R; Schultz, Mark D; Sharma, Arun

    2015-03-17

    A data center cooling system may include heat transfer equipment to cool a liquid coolant without vapor compression refrigeration, and the liquid coolant is used on a liquid cooled information technology equipment rack housed in the data center. The system may also include a controller-apparatus to regulate the liquid coolant flow to the liquid cooled information technology equipment rack through a range of liquid coolant flow values based upon information technology equipment temperature thresholds.

  6. Stochastic cooling in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Brennan,J.M.; Blaskiewicz, M. M.; Severino, F.

    2009-05-04

    After the success of longitudinal stochastic cooling of bunched heavy ion beam in RHIC, transverse stochastic cooling in the vertical plane of Yellow ring was installed and is being commissioned with proton beam. This report presents the status of the effort and gives an estimate, based on simulation, of the RHIC luminosity with stochastic cooling in all planes.

  7. Laser cooling of solids

    OpenAIRE

    Nemova, Galina

    2009-01-01

    Parallel to advances in laser cooling of atoms and ions in dilute gas phase, which has progressed immensely, resulting in physics Nobel prizes in 1997 and 2001, major progress has recently been made in laser cooling of solids. I compare the physical nature of the laser cooling of atoms and ions with that of the laser cooling of solids. I point out all advantages of this new and very promising area of laser physics. Laser cooling of solids (optical refrigeration) at the present time can be lar...

  8. Radial vibrations of BPS skyrmions

    CERN Document Server

    Adam, C; Romanczukiewicz, T; Wereszczynski, A

    2016-01-01

    We study radial vibrations of spherically symmetric skyrmions in the BPS Skyrme model. Concretely, we numerically solve the linearised field equations for small fluctuations in a skyrmion background, both for linearly stable oscillations and for (unstable) resonances. This is complemented by numerical solutions of the full nonlinear system, which confirm all the results of the linear analysis. In all cases, the resulting fundamental excitation provides a rather accurate value for the Roper resonance, supporting the hypothesis that the BPS Skyrme model already gives a reasonable approximate description of this resonance.

  9. Countercurrent aortography via radial artery

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Hyung Kuk; Lee, Young Chun; Lee, Seung Chul; Jeon, Seok Chol; Joo, Kyung Bin; Lee, Seung Ro; Kim, Soon Yong [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    1987-06-15

    Countercurrent aortography via radial artery was performed for detection of aortic arch anomalies in 4 infants with congenital heart disease. Author's cases of aortic arch anomalies were 3 cases of PDA, 1 case of coarctation of aorta, and 1 case of occlusion of anastomosis site on subclavian artery B-T shunt. And aberrant origin of the right SCA, interrupted aortic arch, hypoplastic aorta, anomalous origin of the right pulmonary artery from the ascending aorta can be demonstrated by this method. Countercurrent aortography affords an safe and simple method for detection of aortic arch anomalies without retrograde arterial catheterization, especially in small infants or premature babies.

  10. Stochastic cooling in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Brennan J. M.; Blaskiewicz, M.; Mernick, K.

    2012-05-20

    The full 6-dimensional [x,x'; y,y'; z,z'] stochastic cooling system for RHIC was completed and operational for the FY12 Uranium-Uranium collider run. Cooling enhances the integrated luminosity of the Uranium collisions by a factor of 5, primarily by reducing the transverse emittances but also by cooling in the longitudinal plane to preserve the bunch length. The components have been deployed incrementally over the past several runs, beginning with longitudinal cooling, then cooling in the vertical planes but multiplexed between the Yellow and Blue rings, next cooling both rings simultaneously in vertical (the horizontal plane was cooled by betatron coupling), and now simultaneous horizontal cooling has been commissioned. The system operated between 5 and 9 GHz and with 3 x 10{sup 8} Uranium ions per bunch and produces a cooling half-time of approximately 20 minutes. The ultimate emittance is determined by the balance between cooling and emittance growth from Intra-Beam Scattering. Specific details of the apparatus and mathematical techniques for calculating its performance have been published elsewhere. Here we report on: the method of operation, results with beam, and comparison of results to simulations.

  11. A fully relativistic radial fall

    CERN Document Server

    Spallicci, Alessandro D A M

    2014-01-01

    Radial fall has historically played a momentous role. It is one of the most classical problems, the solutions of which represent the level of understanding of gravitation in a given epoch. A {\\it gedankenexperiment} in a modern frame is given by a small body, like a compact star or a solar mass black hole, captured by a supermassive black hole. The mass of the small body itself and the emission of gravitational radiation cause the departure from the geodesic path due to the back-action, that is the self-force. For radial fall, as any other non-adiabatic motion, the instantaneous identity of the radiated energy and the loss of orbital energy cannot be imposed and provide the perturbed trajectory. In the first part of this letter, we present the effects due to the self-force computed on the geodesic trajectory in the background field. Compared to the latter trajectory, in the Regge-Wheeler, harmonic and all others smoothly related gauges, a far observer concludes that the self-force pushes inward (not outward) ...

  12. Cool Star Science with the FIRE Spectrograph

    CERN Document Server

    Burgasser, Adam J; Bochanski, John J; Melis, Carl; McMurtry, Craig; Pipher, Judy; Forrest, William; Cushing, Michael C; Looper, Dagny L; Mohanty, Subhanjoy

    2010-01-01

    The Folded-port InfraRed Echellette (FIRE) has recently been commissioned on the Magellan 6.5m Baade Telescope. This single object, near-infrared spectrometer simultaneously covers the 0.85-2.45 micron window in both cross-dispersed (R ~ 6000) or prism-dispersed (R ~ 250-350) modes. FIRE's compact configuration, high transmission optics and high quantum efficiency detector provides considerable sensitivity in the near-infrared, making it an ideal instrument for studies of cool stars and brown dwarfs. Here we present some of the first cool star science results with FIRE based on commissioning and science verification observations, including evidence of clouds in a planetary-mass brown dwarf, accretion and jet emission in the low-mass T Tauri star TWA 30B, radial velocities of T-type brown dwarfs, and near-infrared detection of a debris disk associated with the DAZ white dwarf GALEX 1931+01.

  13. A scaling law of radial gas distribution in disk galaxies

    Science.gov (United States)

    Wang, Zhong

    1990-01-01

    Based on the idea that local conditions within a galactic disk largely determine the region's evolution time scale, researchers built a theoretical model to take into account molecular cloud and star formations in the disk evolution process. Despite some variations that may be caused by spiral arms and central bulge masses, they found that many late-type galaxies show consistency with the model in their radial atomic and molecular gas profiles. In particular, researchers propose that a scaling law be used to generalize the gas distribution characteristics. This scaling law may be useful in helping to understand the observed gas contents in many galaxies. Their model assumes an exponential mass distribution with disk radius. Most of the mass are in atomic gas state at the beginning of the evolution. Molecular clouds form through a modified Schmidt Law which takes into account gravitational instabilities in a possible three-phase structure of diffuse interstellar medium (McKee and Ostriker, 1977; Balbus and Cowie, 1985); whereas star formation proceeds presumably unaffected by the environmental conditions outside of molecular clouds (Young, 1987). In such a model both atomic and molecular gas profiles in a typical galactic disk (as a result of the evolution) can be fitted simultaneously by adjusting the efficiency constants. Galaxies of different sizes and masses, on the other hand, can be compared with the model by simply scaling their characteristic length scales and shifting their radial ranges to match the assumed disk total mass profile sigma tot(r).

  14. Cooling by Thermodynamic Induction

    Science.gov (United States)

    Patitsas, S. N.

    2017-03-01

    A method is described for cooling conductive channels to below ambient temperature. The thermodynamic induction principle dictates that the electrically biased channel will cool if the electrical conductance decreases with temperature. The extent of this cooling is calculated in detail for both cases of ballistic and conventional transport with specific calculations for carbon nanotubes and conventional metals, followed by discussions for semiconductors, graphene, and metal-insulator transition systems. A theorem is established for ballistic transport stating that net cooling is not possible. For conventional transport, net cooling is possible over a broad temperature range, with the range being size-dependent. A temperature clamping scheme for establishing a metastable nonequilibrium stationary state is detailed and followed with discussion of possible applications to on-chip thermoelectric cooling in integrated circuitry and quantum computer systems.

  15. Cooling by Thermodynamic Induction

    Science.gov (United States)

    Patitsas, S. N.

    2016-11-01

    A method is described for cooling conductive channels to below ambient temperature. The thermodynamic induction principle dictates that the electrically biased channel will cool if the electrical conductance decreases with temperature. The extent of this cooling is calculated in detail for both cases of ballistic and conventional transport with specific calculations for carbon nanotubes and conventional metals, followed by discussions for semiconductors, graphene, and metal-insulator transition systems. A theorem is established for ballistic transport stating that net cooling is not possible. For conventional transport, net cooling is possible over a broad temperature range, with the range being size-dependent. A temperature clamping scheme for establishing a metastable nonequilibrium stationary state is detailed and followed with discussion of possible applications to on-chip thermoelectric cooling in integrated circuitry and quantum computer systems.

  16. Radiant Floor Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2008-01-01

    In many countries, hydronic radiant floor systems are widely used for heating all types of buildings such as residential, churches, gymnasiums, hospitals, hangars, storage buildings, industrial buildings, and smaller offices. However, few systems are used for cooling.This article describes a floor...... cooling system that includes such considerations as thermal comfort of the occupants, which design parameters will influence the cooling capacity and how the system should be controlled. Examples of applications are presented....

  17. Sympathetic cooling of molecules with laser-cooled atoms

    Science.gov (United States)

    Hudson, Eric

    2014-05-01

    Cooling molecules through collisions with laser-cooled atoms is an attractive route to ultracold, ground state molecules. The technique is simple, applicable to a wide class of molecules, and does not require molecule specific laser systems. Particularly suited to this technique are charged molecules, which can be trapped indefinitely, even at room temperature, and undergo strong, short-ranged collisions with ultracold atoms. In this talk, I will focus on recent efforts to use the combination of a magneto-optical trap (MOT) and an ion trap, dubbed the MOTion trap, to produce cold, ground state diatomic charged molecules. The low-energy internal structure of these diatomic molecules, e.g. the electric dipole moment and vibrational, rotational, and Ω-doublet levels, presents a host of opportunities for advances in quantum simulation, precision measurement, cold chemistry, and quantum information. Excitingly, recent proof-of-principle experiments have demonstrated that the MOTion trap is extremely efficient at cooling the vibrational motion of molecular ions. Supported by the ARO and NSF.

  18. Initial Cooling Experiment (ICE)

    CERN Multimedia

    Photographic Service

    1978-01-01

    In 1977, in a record-time of 9 months, the magnets of the g-2 experiment were modified and used to build a proton/antiproton storage ring: the "Initial Cooling Experiment" (ICE). It served for the verification of the cooling methods to be used for the "Antiproton Project". Stochastic cooling was proven the same year, electron cooling followed later. Also, with ICE the experimental lower limit for the antiproton lifetime was raised by 9 orders of magnitude: from 2 microseconds to 32 hours. For its previous life as g-2 storage ring, see 7405430. More on ICE: 7711282, 7809081, 7908242.

  19. High energy electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Parkhomchuk, V. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)

    1997-09-01

    High energy electron cooling requires a very cold electron beam. The questions of using electron cooling with and without a magnetic field are presented for discussion at this workshop. The electron cooling method was suggested by G. Budker in the middle sixties. The original idea of the electron cooling was published in 1966. The design activities for the NAP-M project was started in November 1971 and the first run using a proton beam occurred in September 1973. The first experiment with both electron and proton beams was started in May 1974. In this experiment good result was achieved very close to theoretical prediction for a usual two component plasma heat exchange.

  20. Power electronics cooling apparatus

    Science.gov (United States)

    Sanger, Philip Albert; Lindberg, Frank A.; Garcen, Walter

    2000-01-01

    A semiconductor cooling arrangement wherein a semiconductor is affixed to a thermally and electrically conducting carrier such as by brazing. The coefficient of thermal expansion of the semiconductor and carrier are closely matched to one another so that during operation they will not be overstressed mechanically due to thermal cycling. Electrical connection is made to the semiconductor and carrier, and a porous metal heat exchanger is thermally connected to the carrier. The heat exchanger is positioned within an electrically insulating cooling assembly having cooling oil flowing therethrough. The arrangement is particularly well adapted for the cooling of high power switching elements in a power bridge.

  1. Formulas for Radial Transport in Protoplanetary Disks

    Science.gov (United States)

    Desch, Steven J.; Estrada, Paul R.; Kalyaan, Anusha; Cuzzi, Jeffrey N.

    2017-05-01

    The quantification of the radial transport of gaseous species and solid particles is important to many applications in protoplanetary disk evolution. An especially important example is determining the location of the water snow lines in a disk, which requires computing the rates of outward radial diffusion of water vapor and the inward radial drift of icy particles; however, the application is generalized to evaporation fronts of all volatiles. We review the relevant formulas using a uniform formalism. This uniform treatment is necessary because the literature currently contains at least six mutually exclusive treatments of radial diffusion of gas, only one of which is correct. We derive the radial diffusion equations from first principles using Fick's law. For completeness, we also present the equations for radial transport of particles. These equations may be applied to studies of diffusion of gases and particles in protoplanetary and other accretion disks.

  2. de secador de flujo radial

    Directory of Open Access Journals (Sweden)

    Néstor Durango

    2005-01-01

    Full Text Available En este artículo se presentan los resultados obtenidos en la investigación realizada para establecer la influencia e importancia de las variables cantidad de yuca, relación superficie a volumen del material de los pedazos de yuca, velocidad del ventilador y temperatura del aire de recirculación, en el proceso de secado de yuca en un modelo de secador de flujo radial. La metodología experimental utilizada fue el diseño de experimentos factoriales, la cual, mediante una serie de análisis estadísticos, posibilitó la caracterización del proceso para un tiempo de secado de tres horas y la obtención de un modelo matemático que describe su comportamiento.

  3. Radial keratotomy associated endothelial degeneration

    Directory of Open Access Journals (Sweden)

    Moshirfar M

    2012-02-01

    Full Text Available Majid Moshirfar, Andrew Ollerton, Rodmehr T Semnani, Maylon HsuJohn A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USAPurpose: To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK and varying degrees of endothelial degeneration.Methods: Retrospective case series were used.Results: Thirteen eyes (seven patients were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years (range: 38–72 years, averaging 18.7 years (range: 11–33 years after RK. The presentation of guttata varied in degree from moderate to severe. Best corrected visual acuity (BCVA ranged from 20/25 to 20/80. All patients had a history of bilateral RK, except one patient who did not develop any guttata in the eye without prior RK. No patients reported a family history of Fuch’s Dystrophy. One patient underwent a penetrating keratoplasty in one eye and a Descemet’s stripping automated endothelial keratoplasty (DSAEK in the other eye.Conclusions: RK may induce a spectrum of endothelial degeneration. In elderly patients, the findings of guttata may signify comorbid Fuch’s dystrophy in which RK incisions could potentially hasten endothelial decomposition. In these select patients with stable cornea topography and prior RK, DSAEK may successfully treat RK endothelial degeneration.Keywords: radial keratotomy, RK, Descemet’s stripping automated endothelial keratoplasty, DSAEK, guttata, endothelial degeneration, Fuch’s dystrophy

  4. A CONSERVATIVE VIEW OF RADIAL KERATOTOMY

    Institute of Scientific and Technical Information of China (English)

    Steven; Olkowski; Walter; J.; Stark; John; D.; Gottsch; Gerri; Goodman; Daniel; Goodman; A.E.; Maumenee; Ivan; Esente

    1991-01-01

    It has been known for almost a century that radial keratotomy (RK) will flatten the cornea and reduce myopia. Since the introduction of radial keratotomy (RK) in the United States by Bores in 1978, there have been many published studies documenting the effects of this procedure. The questions. about radial keratotomy today are not only quantitative but also qualitative in nature. We know this technique can flatten the cornea, but how reliably can the results be predicted? Does the patient benefit suffic...

  5. On radial geodesic forcing of zonal modes

    OpenAIRE

    Kendl, Alexander

    2011-01-01

    The elementary local and global influence of geodesic field line curvature on radial dispersion of zonal modes in magnetised plasmas is analysed with a primitive drift wave turbulence model. A net radial geodesic forcing of zonal flows and geodesic acoustic modes can not be expected in any closed toroidal magnetic confinement configuration, since the flux surface average of geodesic curvature identically vanishes. Radial motion of poloidally elongated zonal jets may occur in the presence of g...

  6. Stirling Engine With Radial Flow Heat Exchangers

    Science.gov (United States)

    Vitale, N.; Yarr, George

    1993-01-01

    Conflict between thermodynamical and structural requirements resolved. In Stirling engine of new cylindrical configuration, regenerator and acceptor and rejector heat exchangers channel flow of working gas in radial direction. Isotherms in regenerator ideally concentric cylinders, and gradient of temperature across regenerator radial rather than axial. Acceptor and rejector heat exchangers located radially inward and outward of regenerator, respectively. Enables substantial increase in power of engine without corresponding increase in diameter of pressure vessel.

  7. Hollow Cathode With Multiple Radial Orifices

    Science.gov (United States)

    Brophy, John R.

    1992-01-01

    Improved hollow cathode serving as source of electrons has multiple radial orifices instead of single axial orifice. Distributes ion current more smoothly, over larger area. Prototype of high-current cathodes for ion engines in spacecraft. On Earth, cathodes used in large-diameter ion sources for industrial processing of materials. Radial orientation of orifices in new design causes current to be dispersed radially in vicinity of cathode. Advantageous where desireable to produce plasma more nearly uniform over wider region around cathode.

  8. Apparatus for laser slowing and cooling of molecules

    Science.gov (United States)

    2016-10-09

    SECURITY CLASSIFICATION OF: This is the final report for our DURIP grant entitled "Apparatus for Laser Slowing and cooling of Molecules". We have... cooling of a new molecular species, TlF. We have also successfully acquired and assembled the parts for a custom laser system, which produces long...Distribution Unlimited UU UU UU UU 09-10-2016 1-Sep-2012 31-Aug-2014 Final Report: Apparatus for laser slowing and cooling of molecules The views

  9. On radial geodesic forcing of zonal modes

    CERN Document Server

    Kendl, Alexander

    2011-01-01

    The elementary local and global influence of geodesic field line curvature on radial dispersion of zonal modes in magnetised plasmas is analysed with a primitive drift wave turbulence model. A net radial geodesic forcing of zonal flows and geodesic acoustic modes can not be expected in any closed toroidal magnetic confinement configuration, since the flux surface average of geodesic curvature identically vanishes. Radial motion of poloidally elongated zonal jets may occur in the presence of geodesic acoustic mode activity. Phenomenologically a radial propagation of zonal modes shows some characteristics of a classical analogon to second sound in quantum condensates.

  10. Toeplitz Operators with Essentially Radial Symbols

    Directory of Open Access Journals (Sweden)

    Roberto C. Raimondo

    2012-01-01

    Full Text Available For Topelitz operators with radial symbols on the disk, there are important results that characterize boundedness, compactness, and its relation to the Berezin transform. The notion of essentially radial symbol is a natural extension, in the context of multiply-connected domains, of the notion of radial symbol on the disk. In this paper we analyze the relationship between the boundary behavior of the Berezin transform and the compactness of when ∈2(Ω is essentially radial and Ω is multiply-connected domains.

  11. Elastocaloric cooling: Stretch to actively cool

    Science.gov (United States)

    Ossmer, Hinnerk; Kohl, Manfred

    2016-10-01

    The elastocaloric effect can be exploited in solid-state cooling technologies as an alternative to conventional vapour compression. Now, an elastocaloric device based on the concept of active regeneration achieves a temperature lift of 15.3 K and efficiencies competitive with other caloric-based approaches.

  12. Analysis of radial basis function interpolation approach

    Institute of Scientific and Technical Information of China (English)

    Zou You-Long; Hu Fa-Long; Zhou Can-Can; Li Chao-Liu; Dunn Keh-Jim

    2013-01-01

    The radial basis function (RBF) interpolation approach proposed by Freedman is used to solve inverse problems encountered in well-logging and other petrophysical issues. The approach is to predict petrophysical properties in the laboratory on the basis of physical rock datasets, which include the formation factor, viscosity, permeability, and molecular composition. However, this approach does not consider the effect of spatial distribution of the calibration data on the interpolation result. This study proposes a new RBF interpolation approach based on the Freedman's RBF interpolation approach, by which the unit basis functions are uniformly populated in the space domain. The inverse results of the two approaches are comparatively analyzed by using our datasets. We determine that although the interpolation effects of the two approaches are equivalent, the new approach is more flexible and beneficial for reducing the number of basis functions when the database is large, resulting in simplification of the interpolation function expression. However, the predicted results of the central data are not sufficiently satisfied when the data clusters are far apart.

  13. Measure Guideline: Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Springer, D.; Dakin, B.; German, A.

    2012-04-01

    The purpose of this measure guideline on ventilation cooling is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

  14. The final cool down

    CERN Multimedia

    Thursday 29th May, the cool-down of the final sector (sector 4-5) of LHC has begun, one week after the start of the cool-down of sector 1-2. It will take five weeks for the sectors to be cooled from room temperature to 5 K and a further two weeks to complete the cool down to 1.9 K and the commissioning of cryogenic instrumentation, as well as to fine tune the cryogenic plants and the cooling loops of cryostats.Nearly a year and half has passed since sector 7-8 was cooled for the first time in January 2007. For Laurent Tavian, AT/CRG Group Leader, reaching the final phase of the cool down is an important milestone, confirming the basic design of the cryogenic system and the ability to operate complete sectors. “All the sectors have to operate at the same time otherwise we cannot inject the beam into the machine. The stability and reliability of the cryogenic system and its utilities are now very important. That will be the new challenge for the coming months,” he explains. The status of the cool down of ...

  15. Solar absorption cooling

    NARCIS (Netherlands)

    Kim, D.-S.

    2007-01-01

    As the world concerns more and more on global climate changes and depleting energy resources, solar cooling technology receives increasing interests from the public as an environment-friendly and sustainable alternative. However, making a competitive solar cooling machine for the market still

  16. Passive evaporative cooling

    NARCIS (Netherlands)

    Tzoulis, A.

    2011-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Smart & Bioclimatic Design. Passive techniques for cooling are a great way to cope with the energy problem of the present day. This manual introduces passive cooling by evaporation. These methods have been used for many years in traditi

  17. Data center cooling method

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Dang, Hien P.; Parida, Pritish R.; Schultz, Mark D.; Sharma, Arun

    2015-08-11

    A method aspect for removing heat from a data center may use liquid coolant cooled without vapor compression refrigeration on a liquid cooled information technology equipment rack. The method may also include regulating liquid coolant flow to the data center through a range of liquid coolant flow values with a controller-apparatus based upon information technology equipment temperature threshold of the data center.

  18. Liquid Cooled Garments

    Science.gov (United States)

    1979-01-01

    Astronauts working on the surface of the moon had to wear liquid-cooled garments under their space suits as protection from lunar temperatures which sometimes reach 250 degrees Fahrenheit. In community service projects conducted by NASA's Ames Research Center, the technology developed for astronaut needs has been adapted to portable cooling systems which will permit two youngsters to lead more normal lives.

  19. Solar absorption cooling

    NARCIS (Netherlands)

    Kim, D.-S.

    2007-01-01

    As the world concerns more and more on global climate changes and depleting energy resources, solar cooling technology receives increasing interests from the public as an environment-friendly and sustainable alternative. However, making a competitive solar cooling machine for the market still remain

  20. Coherent electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko,V.

    2009-05-04

    Cooling intense high-energy hadron beams remains a major challenge in modern accelerator physics. Synchrotron radiation is still too feeble, while the efficiency of two other cooling methods, stochastic and electron, falls rapidly either at high bunch intensities (i.e. stochastic of protons) or at high energies (e-cooling). In this talk a specific scheme of a unique cooling technique, Coherent Electron Cooling, will be discussed. The idea of coherent electron cooling using electron beam instabilities was suggested by Derbenev in the early 1980s, but the scheme presented in this talk, with cooling times under an hour for 7 TeV protons in the LHC, would be possible only with present-day accelerator technology. This talk will discuss the principles and the main limitations of the Coherent Electron Cooling process. The talk will describe the main system components, based on a high-gain free electron laser driven by an energy recovery linac, and will present some numerical examples for ions and protons in RHIC and the LHC and for electron-hadron options for these colliders. BNL plans a demonstration of the idea in the near future.

  1. Hydronic rooftop cooling systems

    Science.gov (United States)

    Bourne, Richard C.; Lee, Brian Eric; Berman, Mark J.

    2008-01-29

    A roof top cooling unit has an evaporative cooling section that includes at least one evaporative module that pre-cools ventilation air and water; a condenser; a water reservoir and pump that captures and re-circulates water within the evaporative modules; a fan that exhausts air from the building and the evaporative modules and systems that refill and drain the water reservoir. The cooling unit also has a refrigerant section that includes a compressor, an expansion device, evaporator and condenser heat exchangers, and connecting refrigerant piping. Supply air components include a blower, an air filter, a cooling and/or heating coil to condition air for supply to the building, and optional dampers that, in designs that supply less than 100% outdoor air to the building, control the mixture of return and ventilation air.

  2. INITIAL COOLING EXPERIMENT (ICE)

    CERN Multimedia

    1979-01-01

    ICE was built in 1977, using the modified bending magnets of the g-2 muon storage ring (see 7405430). Its purpose was to verify the validity of stochastic and electron cooling for the antiproton project. Stochastic cooling proved a resounding success early in 1978 and the antiproton project could go ahead, now entirely based on stochastic cooling. Electron cooling was experimented with in 1979. The 26 kV equipment is housed in the cage to the left of the picture, adjacent to the "e-cooler" located in a straight section of the ring. With some modifications, the cooler was later transplanted into LEAR (Low Energy Antiproton Ring) and then, with further modifications, into the AD (Antiproton Decelerator), where it cools antiprotons to this day (2006). See also: 7711282, 7802099, 7809081.

  3. INITIAL COOLING EXPERIMENT (ICE)

    CERN Multimedia

    1978-01-01

    ICE was built in 1977, in a record time of 9 months, using the modified bending magnets of the g-2 muon storage ring. Its purpose was to verify the validity of stochastic and electron cooling for the antiproton project, to be launched in 1978. Already early in 1978, stochastic cooling proved a resounding success, such that the antiproton (p-pbar)project was entirely based on it. Tests of electron cooling followed later: protons of 46 MeV kinetic energy were cooled with an electron beam of 26 kV and 1.3 A. The cage seen prominently in the foreground houses the HV equipment, adjacent to the "cooler" installed in a straight section of the ring. With some modifications, the cooler was later transplanted into LEAR (Low Energy Antiproton Ring) and then, with further modifications, into the AD (Antiproton Decelerator), where it cools antiprotons to this day (2006). See also: 7711282, 7802099, 7908242.

  4. Radial head button holing: a cause of irreducible anterior radial head dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Su-Mi; Chai, Jee Won; You, Ja Yeon; Park, Jina [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Bae, Kee Jeong [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Orthopedic Surgery, Seoul (Korea, Republic of)

    2016-10-15

    ''Buttonholing'' of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction. (orig.)

  5. Ultraviolet laser desorption/ionization mass spectrometry of single-core and multi-core polyaromatic hydrocarbons under variable conditions of collisional cooling: insights into the generation of molecular ions, fragments and oligomers.

    Science.gov (United States)

    Gámez, Francisco; Hortal, Ana R; Martínez-Haya, Bruno; Soltwisch, Jens; Dreisewerd, Klaus

    2014-11-01

    The ultraviolet laser desorption/ionization of polyaromatic hydrocarbons (PAHs) has been investigated under different background pressures of an inert gas (up to 1.2 mbar of N2) in the ion source of a hybrid, orthogonal-extracting time-of-flight mass spectrometer (oTOF-MS). The study includes an ensemble of six model PAHs with isolated single polyaromatic cores and four ones with multiple cross-linked aromatic and polyaromatic cores. In combination with a weak ion extraction field, the variation of the buffer gas pressure allowed to control the degree of collisional cooling of the desorbed PAHs and, thus, to modulate their decomposition into fragments. The dominant fragmentation channels observed are related to dehydrogenation of the PAHs, in most cases through the cleavage of even numbers of C-H bonds. Breakage of C-C bonds leading to the fragmentation of rings, side chains and core linkages is also observed, in particular, at low buffer gas pressures. The precise patterns of the combined fragmentation processes vary significantly between the PAHs. The highest abundances of molecular PAH ions and cleanest mass spectra were consistently obtained at the highest buffer gas pressure of 1.2 mbar. The effective quenching of the fragmentation pathways at this elevated pressure improves the sensitivity and data interpretation for analytical applications, although the fragmentation of side chains and of bonds between (poly)aromatic cores is not completely suppressed in all cases. Moreover, these results suggest that the detected fragments are generated through thermal equilibrium processes rather than as a result of rapid photolysis. This assumption is further corroborated by a laser desorption/ionization post-source decay analysis using an axial time-of-flight MS. In line with these findings, covalent oligomers of the PAHs, which are presumably formed by association of two or more dehydrogenated fragments, are detected with higher abundances at the lower buffer gas

  6. HEAT-UP AND COOL-DOWN TEMPERATURE-DEPENDENT HYDRIDE REORIENTATION BEHAVIORS IN ZIRCONIUM ALLOY CLADDING TUBES

    Directory of Open Access Journals (Sweden)

    JU-JIN WON

    2014-10-01

    Full Text Available Hydride reorientation behaviors of PWR cladding tubes under typical interim dry storage conditions were investigated with the use of as-received 250 and 485ppm hydrogen-charged Zr-Nb alloy cladding tubes. In order to evaluate the effect of typical cool-down processes on the radial hydride precipitation, two terminal heat-up temperatures of 300 and 400°C, as well as two terminal cool-down temperatures of 200 and 300°C, were considered. In addition, two cooling rates of 2.5 and 8.0°C/min during the cool-down processes were taken into account along with zero stress or a tensile hoop stress of 150MPa. It was found that the 250ppm hydrogen-charged specimen experiencing the higher terminal heat-up temperature and the lower terminal cool-down temperature generated the highest number of radial hydrides during the cool-down process under 150MPa hoop tensile stress, which may be explained by terminal solid hydrogen solubilities for precipitation, and dissolution and remaining circumferential hydrides at the terminal heat-up temperatures. In addition, the slower cool-down rate generates the larger number of radial hydrides due to a cooling rate-dependent, longer residence time at a relatively high temperature that can accelerate the radial hydride nucleation and growth.

  7. Optimization of the breeder zone cooling tubes of the DEMO Water-Cooled Lithium Lead breeding blanket

    Energy Technology Data Exchange (ETDEWEB)

    Di Maio, P.A.; Arena, P.; Bongiovì, G. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo, Viale delle Scienze, Palermo (Italy); Chiovaro, P., E-mail: pierluigi.chiovaro@unipa.it [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo, Viale delle Scienze, Palermo (Italy); Del Nevo, A. [ENEA Brasimone, Camugnano, BO (Italy); Forte, R. [Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università di Palermo, Viale delle Scienze, Palermo (Italy)

    2016-11-01

    Highlights: • Determination of an optimal configuration for the breeder zone cooling tubes. • Attention has been focused on the toroidal–radial breeder zone cooling tubes lay out. • A theoretical-computational approach based on the Finite Element Method (FEM) has been followed, adopting a qualified commercial FEM code. • Five different configurations have been investigated to optimize the breeder zone cooling tubes arrangement fulfilling all the rules prescribed by safety codes. - Abstract: The determination of an optimal configuration for the breeder zone (BZ) cooling tubes is one of the most important issues in the DEMO Water-Cooled Lithium Lead (WCLL) breeding blanket R&D activities, since BZ cooling tubes spatial distribution should ensure an efficient heat power removal from the breeder, avoiding hotspots occurrence in the thermal field. Within the framework of R&D activities supported by the HORIZON 2020 EUROfusion Consortium action on the DEMO WCLL breeding blanket design, a campaign of parametric analyses has been launched at the Department of Energy, Information Engineering and Mathematical Models of the University of Palermo (DEIM), in close cooperation with ENEA-Brasimone, in order to assess the potential influence of BZ cooling tubes number on the thermal performances of the DEMO WCLL outboard breeding blanket equatorial module under the nominal steady state operative conditions envisaged for it, optimizing their geometric configuration and taking also into account that a large number of cooling pipes can deteriorate the tritium breeding performances of the module. In particular, attention has been focused on the toroidal-radial option for the BZ tube bundles lay-out and a parametric study has been carried out taking into account different tube bundles arrangement within the module. The study has been carried out following a numerical approach, based on the finite element method (FEM), and adopting a qualified commercial FEM code. Results

  8. Integrated axial and tangential serpentine cooling circuit in a turbine airfoil

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ching-Pang; Jiang, Nan; Marra, John J; Rudolph, Ronald J; Dalton, John P

    2015-05-05

    A continuous serpentine cooling circuit forming a progression of radial passages (44, 45, 46, 47A, 48A) between pressure and suction side walls (52, 54) in a MID region of a turbine airfoil (24). The circuit progresses first axially, then tangentially, ending in a last radial passage (48A) adjacent to the suction side (54) and not adjacent to the pressure side (52). The passages of the axial progression (44, 45, 46) may be adjacent to both the pressure and suction side walls of the airfoil. The next to last radial passage (47A) may be adjacent to the pressure side wall and not adjacent to the suction side wall. The last two radial passages (47A, 48A) may be longer along the pressure and suction side walls respectively than they are in a width direction, providing increased direct cooling surface area on the interiors of these hot walls.

  9. Flow structure and heat exchange analysis in internal cooling channel of gas turbine blade

    Science.gov (United States)

    Szwaba, Ryszard; Kaczynski, Piotr; Doerffer, Piotr; Telega, Janusz

    2016-08-01

    This paper presents the study of the flow structure and heat transfer, and also their correlations on the four walls of a radial cooling passage model of a gas turbine blade. The investigations focus on heat transfer and aerodynamic measurements in the channel, which is an accurate representation of the configuration used in aeroengines. Correlations for the heat transfer coefficient and the pressure drop used in the design of radial cooling passages are often developed from simplified models. It is important to note that real engine passages do not have perfect rectangular cross sections, but include corner fillet, ribs with fillet radii and special orientation. Therefore, this work provides detailed fluid flow and heat transfer data for a model of radial cooling geometry which possesses very realistic features.

  10. Radial keratotomy associated endothelial degeneration.

    Science.gov (United States)

    Moshirfar, Majid; Ollerton, Andrew; Semnani, Rodmehr T; Hsu, Maylon

    2012-01-01

    To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK) and varying degrees of endothelial degeneration. Retrospective case series were used. Thirteen eyes (seven patients) were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years (range: 38-72 years), averaging 18.7 years (range: 11-33 years) after RK. The presentation of guttata varied in degree from moderate to severe. Best corrected visual acuity (BCVA) ranged from 20/25 to 20/80. All patients had a history of bilateral RK, except one patient who did not develop any guttata in the eye without prior RK. No patients reported a family history of Fuch's Dystrophy. One patient underwent a penetrating keratoplasty in one eye and a Descemet's stripping automated endothelial keratoplasty (DSAEK) in the other eye. RK may induce a spectrum of endothelial degeneration. In elderly patients, the findings of guttata may signify comorbid Fuch's dystrophy in which RK incisions could potentially hasten endothelial decomposition. In these select patients with stable cornea topography and prior RK, DSAEK may successfully treat RK endothelial degeneration.

  11. Computer Simulation of Radial Immunodiffusion

    Science.gov (United States)

    Trautman, Rodes

    1972-01-01

    Theories of diffusion with chemical reaction are reviewed as to their contributions toward developing an algorithm needed for computer simulation of immunodiffusion. The Spiers-Augustin moving sink and the Engelberg stationary sink theories show how the antibody-antigen reaction can be incorporated into boundary conditions of the free diffusion differential equations. For this, a stoichiometric precipitate was assumed and the location of precipitin lines could be predicted. The Hill simultaneous linear adsorption theory provides a mathematical device for including another special type of antibody-antigen reaction in antigen excess regions of the gel. It permits an explanation for the lowered antigen diffusion coefficient, observed in the Oudin arrangement of single linear diffusion, but does not enable prediction of the location of precipitin lines. The most promising mathematical approach for a general solution is implied in the Augustin alternating cycle theory. This assumes the immunodiffusion process can be evaluated by alternating computation cycles: free diffusion without chemical reaction and chemical reaction without diffusion. The algorithm for the free diffusion update cycle, extended to both linear and radial geometries, is given in detail since it was based on gross flow rather than more conventional expressions in terms of net flow. Limitations on the numerical integration process using this algorithm are illustrated for free diffusion from a cylindrical well. PMID:4629869

  12. Direct laser cooling of the BH molecule

    Science.gov (United States)

    Holland, Darren; Truppe, Stefan; Hendricks, Richard; Sauer, Ben; Tarbutt, Michael

    2015-03-01

    Ultracold polar molecules are of interest for a variety of applications, including tests of fundamental physics, ultracold chemistry, and simulation of many-body quantum systems. The laser cooling techniques that have been so successful in producing ultracold atoms are difficult to apply to molecules. Recently however, laser cooling has been applied successfully to a few molecular species, and a magneto-optical trap of SrF molecules has now been demonstrated. We have investigated the BH molecule as a candidate for laser cooling. We have produced a molecular beam of BH and have measured the branching ratios for the excited electronic state, A1 Π (v' = 0) , to decay to the various vibrational states of the ground electronic state, X1 Σ . We verify that the branching ratio for the spin-forbidden transition to an intermediate triplet state is inconsequentially small. We measure the frequency of the lowest rotational transition of the X state, and the hyperfine structure in the relevant levels of both the X and A states, and determine the nuclear electric quadrupole and magnetic dipole coupling constants. Our results show that a relatively simple laser cooling scheme can be used to cool, slow and trap BH molecules.

  13. Second sector cool down

    CERN Multimedia

    2007-01-01

    At the beginning of July, cool-down is starting in the second LHC sector, sector 4-5. The cool down of sector 4-5 may occasionally generate mist at Point 4, like that produced last January (photo) during the cool-down of sector 7-8.Things are getting colder in the LHC. Sector 7-8 has been kept at 1.9 K for three weeks with excellent stability (see Bulletin No. 16-17 of 16 April 2007). The electrical tests in this sector have got opt to a successful start. At the beginning of July the cryogenic teams started to cool a second sector, sector 4-5. At Point 4 in Echenevex, where one of the LHC’s cryogenic plants is located, preparations for the first phase of the cool-down are underway. During this phase, the sector will first be cooled to 80 K (-193°C), the temperature of liquid nitrogen. As for the first sector, 1200 tonnes of liquid nitrogen will be used for the cool-down. In fact, the nitrogen circulates only at the surface in the ...

  14. Combination radial and thrust magnetic bearing

    Science.gov (United States)

    Blumenstock, Kenneth A. (Inventor)

    2002-01-01

    A combination radial and thrust magnetic bearing is disclosed that allows for both radial and thrust axes control of an associated shaft. The combination radial and thrust magnetic bearing comprises a rotor and a stator. The rotor comprises a shaft, and first and second rotor pairs each having respective rotor elements. The stator comprises first and second stator elements and a magnet-sensor disk. In one embodiment, each stator element has a plurality of split-poles and a corresponding plurality of radial force coils and, in another embodiment, each stator element does not require thrust force coils, and radial force coils are replaced by double the plurality of coils serving as an outer member of each split-pole half.

  15. An unusual cause of radial nerve palsy

    Directory of Open Access Journals (Sweden)

    Agrawal Hemendra Kumar

    2014-06-01

    Full Text Available Neurapraxia frequently occurs following traction injury to the nerve intraoperatively, leading to radial nerve palsy which usually recovers in 5-30 weeks. In our case, we had operated a distal one-third of humeral shaft fracture and fixed it with 4.5 mm limited contact dynamic compression plate. The distal neurovascular status of the limb was assessed postoperatively in the recovery room and was found to be intact and all the sensory-motor functions of the radial nerve were normal. On the second postoperative day, following the suction drain removal and dressing, patient developed immediate radial nerve palsy along with wrist drop. We reviewed theliterature and found no obvious cause for the nerve palsy and concluded that it was due to traction injury to the radial nerve while removing the suction drain in negative pressure. Key words: Radial nerve; Humeral fractures; Paralysis; Diaphyses

  16. Radial velocity moments of dark matter haloes

    CERN Document Server

    Wojtak, R; Gottlöber, S; Mamon, G A; Wojtak, Radoslaw; Lokas, Ewa L.; Gottloeber, Stefan; Mamon, Gary A.

    2005-01-01

    Using cosmological N-body simulations we study the radial velocity distribution in dark matter haloes focusing on the lowest-order even moments, dispersion and kurtosis. We determine the properties of ten massive haloes in the simulation box approximating their density distribution by the NFW formula characterized by the virial mass and concentration. We also calculate the velocity anisotropy parameter of the haloes and find it mildly radial and increasing with distance from the halo centre. The radial velocity dispersion of the haloes shows a characteristic profile with a maximum, while the radial kurtosis profile decreases with distance starting from a value close to Gaussian near the centre. We therefore confirm that dark matter haloes possess intrinsically non-Gaussian, flat-topped velocity distributions. We find that the radial velocity moments of the simulated haloes are very well reproduced by the solutions of the Jeans equations obtained for the halo parameters with the anisotropy measured in the simu...

  17. Measuring the coolness of interactive products: the COOL questionnaire

    DEFF Research Database (Denmark)

    Bruun, Anders; Raptis, Dimitrios; Kjeldskov, Jesper;

    2016-01-01

    is the COOL questionnaire. We based the creation of the questionnaire on literature suggesting that perceived coolness is decomposed to outer cool (the style of a product) and inner cool (the personality characteristics assigned to it). In this paper, we focused on inner cool, and we identified 11 inner cool......, rebelliousness and usability. These factors and their underlying 16 question items comprise the COOL questionnaire. The whole process of creating the questionnaire is presented in detail in this paper and we conclude by discussing our work against related work on coolness and HCI....

  18. Cool WISPs for stellar cooling excesses

    Energy Technology Data Exchange (ETDEWEB)

    Giannotti, Maurizio [Barry Univ., Miami Shores, FL (United States). Physical Sciences; Irastorza, Igor [Zaragoza Univ. (Spain). Dept. de Fisica Teorica; Redondo, Javier [Zaragoza Univ. (Spain). Dept. de Fisica Teorica; Max-Planck-Institut fuer Physik, Muenchen (Germany); Ringwald, Andreas [DESY Hamburg (Germany). Theory Group

    2015-12-15

    Several stellar systems (white dwarfs, red giants, horizontal branch stars and possibly the neutron star in the supernova remnant Cassiopeia A) show a preference for a mild non-standard cooling mechanism when compared with theoretical models. This exotic cooling could be provided by Weakly Interacting Slim Particles (WISPs), produced in the hot cores and abandoning the star unimpeded, contributing directly to the energy loss. Taken individually, these excesses do not show a strong statistical weight. However, if one mechanism could consistently explain several of them, the hint could be significant. We analyze the hints in terms of neutrino anomalous magnetic moments, minicharged particles, hidden photons and axion-like particles (ALPs). Among them, the ALP represents the best solution. Interestingly, the hinted ALP parameter space is accessible to the next generation proposed ALP searches, such as ALPS II and IAXO.

  19. Cool WISPs for stellar cooling excesses

    CERN Document Server

    Giannotti, Maurizio; Redondo, Javier; Ringwald, Andreas

    2015-01-01

    Several stellar systems (white dwarfs, red giants, horizontal branch stars and possibly the neutron star in the supernova remnant Cassiopeia A) show a preference for a mild non-standard cooling mechanism when compared with theoretical models. This exotic cooling could be provided by Weakly Interacting Slim Particles (WISPs), produced in the hot cores and abandoning the star unimpeded, contributing directly to the energy loss. Taken individually, these excesses do not show a strong statistical weight. However, if one mechanism could consistently explain several of them, the hint could be significant. We analyze the hints in terms of neutrino anomalous magnetic moments, minicharged particles, hidden photons and axion-like particles (ALPs). Among them, the ALP represents the best solution. Interestingly, the hinted ALP parameter space is accessible to the next generation proposed ALP searches, such as ALPS II and IAXO.

  20. Homogeneous cooling of mixtures of particle shapes

    Science.gov (United States)

    Hidalgo, R. C.; Serero, D.; Pöschel, T.

    2016-07-01

    In this work, we examine theoretically the cooling dynamics of binary mixtures of spheres and rods. To this end, we introduce a generalized mean field analytical theory, which describes the free cooling behavior of the mixture. The relevant characteristic time scale for the cooling process is derived, depending on the mixture composition and the aspect ratio of the rods. We simulate mixtures of spherocylinders and spheres using a molecular dynamics algorithm implemented on graphics processing unit (GPU) architecture. We systematically study mixtures composed of spheres and rods with several aspect ratios and varying the mixture composition. A homogeneous cooling state, where the time dependence of the system's intensive variables occurs only through a global granular temperature, is identified. We find cooling dynamics in excellent agreement with Haff's law, when using an adequate time scale. Using the scaling properties of the homogeneous cooling dynamics, we estimated numerically the efficiency of the energy interchange between rotational and translational degrees of freedom for collisions between spheres and rods.

  1. Water-cooled electronics

    CERN Document Server

    Dumont, G; Righini, B

    2000-01-01

    LHC experiments demand on cooling of electronic instrumentation will be extremely high. A large number of racks will be located in underground caverns and counting rooms, where cooling by conventional climatisation would be prohibitively expensive. A series of tests on the direct water cooling of VMEbus units and of their standard power supplies is reported. A maximum dissipation of 60 W for each module and more than 1000 W delivered by the power supply to the crate have been reached. These values comply with the VMEbus specifications. (3 refs).

  2. Laser cooling of a diatomic molecule.

    Science.gov (United States)

    Shuman, E S; Barry, J F; Demille, D

    2010-10-14

    It has been roughly three decades since laser cooling techniques produced ultracold atoms, leading to rapid advances in a wide array of fields. Laser cooling has not yet been extended to molecules because of their complex internal structure. However, this complexity makes molecules potentially useful for a wide range of applications. For example, heteronuclear molecules possess permanent electric dipole moments that lead to long-range, tunable, anisotropic dipole-dipole interactions. The combination of the dipole-dipole interaction and the precise control over molecular degrees of freedom possible at ultracold temperatures makes ultracold molecules attractive candidates for use in quantum simulations of condensed-matter systems and in quantum computation. Also, ultracold molecules could provide unique opportunities for studying chemical dynamics and for tests of fundamental symmetries. Here we experimentally demonstrate laser cooling of the polar molecule strontium monofluoride (SrF). Using an optical cycling scheme requiring only three lasers, we have observed both Sisyphus and Doppler cooling forces that reduce the transverse temperature of a SrF molecular beam substantially, to a few millikelvin or less. At present, the only technique for producing ultracold molecules is to bind together ultracold alkali atoms through Feshbach resonance or photoassociation. However, proposed applications for ultracold molecules require a variety of molecular energy-level structures (for example unpaired electronic spin, Omega doublets and so on). Our method provides an alternative route to ultracold molecules. In particular, it bridges the gap between ultracold (submillikelvin) temperatures and the ∼1-K temperatures attainable with directly cooled molecules (for example with cryogenic buffer-gas cooling or decelerated supersonic beams). Ultimately, our technique should allow the production of large samples of molecules at ultracold temperatures for species that are chemically

  3. Cooling Devices in Laser therapy.

    Science.gov (United States)

    Das, Anupam; Sarda, Aarti; De, Abhishek

    2016-01-01

    Cooling devices and methods are now integrated into most laser systems, with a view to protecting the epidermis, reducing pain and erythema and improving the efficacy of laser. On the basis of method employed, it can be divided into contact cooling and non-contact cooling. With respect to timing of irradiation of laser, the nomenclatures include pre-cooling, parallel cooling and post-cooling. The choice of the cooling device is dictated by the laser device, the physician's personal choice with respect to user-friendliness, comfort of the patient, the price and maintenance costs of the device. We hereby briefly review the various techniques of cooling, employed in laser practice.

  4. LHC cooling gains ground

    CERN Multimedia

    Huillet-Miraton Catherine

    The nominal cryogenic conditions of 1.9 K have been achieved in sectors 5-6 and 7-8. This means that a quarter of the machine has reached the nominal conditions for LHC operation, having attained a temperature of below 2 K (-271°C), which is colder than interstellar space! Elsewhere, the cryogenic system in Sector 8-1 has been filled with liquid helium and cooled to 2K and will soon be available for magnet testing. Sectors 6-7 and 2-3 are being cooled down and cool-down operations have started in Sector 3-4. Finally, preparations are in hand for the cool-down of Sector 1-2 in May and of Sector 4-5, which is currently being consolidated. The LHC should be completely cold for the summer. For more information: http://lhc.web.cern.ch/lhc/Cooldown_status.htm.

  5. Why Exercise Is Cool

    Science.gov (United States)

    ... to Know About Puberty Train Your Temper Why Exercise Is Cool KidsHealth > For Kids > Why Exercise Is ... day and your body will thank you later! Exercise Makes Your Heart Happy You may know that ...

  6. Waveguide cooling system

    Science.gov (United States)

    Chen, B. C. J.; Hartop, R. W.

    1981-04-01

    An improved system is described for cooling high power waveguides by the use of cooling ducts extending along the waveguide, which minimizes hot spots at the flanges where waveguide sections are connected together. The cooling duct extends along substantially the full length of the waveguide section, and each flange at the end of the section has a through hole with an inner end connected to the duct and an opposite end that can be aligned with a flange hole in another waveguide section. Earth flange is formed with a drainage groove in its face, between the through hole and the waveguide conduit to prevent leakage of cooling fluid into the waveguide. The ducts have narrowed sections immediately adjacent to the flanges to provide room for the installation of fasteners closely around the waveguide channel.

  7. Warm and Cool Dinosaurs.

    Science.gov (United States)

    Mannlein, Sally

    2001-01-01

    Presents an art activity in which first grade students draw dinosaurs in order to learn about the concept of warm and cool colors. Explains how the activity also helped the students learn about the concept of distance when drawing. (CMK)

  8. Cooling of wood briquettes

    Directory of Open Access Journals (Sweden)

    Adžić Miroljub M.

    2013-01-01

    Full Text Available This paper is concerned with the experimental research of surface temperature of wood briquettes during cooling phase along the cooling line. The cooling phase is an important part of the briquette production technology. It should be performed with care, otherwise the quality of briquettes could deteriorate and possible changes of combustion characteristics of briquettes could happen. The briquette surface temperature was measured with an IR camera and a surface temperature probe at 42 sections. It was found that the temperature of briquette surface dropped from 68 to 34°C after 7 minutes spent at the cooling line. The temperature at the center of briquette, during the 6 hour storage, decreased to 38°C.

  9. Cooling of electronic equipment

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt

    2003-01-01

    Cooling of electronic equipment is studied. The design size of electronic equipment decrease causing the thermal density to increase. This affect the cooling which can cause for example failures of critical components due to overheating or thermal induced stresses. Initially a pin fin heat sink...... is considered as extruded profiles are inadequate for compact designs. An optimal pin fin shape and configuration is sought also taking manufacturing costs into consideration. Standard methods for geometrical modeling and thermal analysis are applied....

  10. Anomalous law of cooling

    OpenAIRE

    Lapas, Luciano C.; Ferreira, Rogelma M. S.; Oliveira, Fernando A.; Rubí, J. Miguel

    2014-01-01

    We analyze the temperature relaxation phenomena of systems in contact with a thermal reservoir that undergo a non-Markovian diffusion process. From a generalized Langevin equation, we show that the temperature is governed by a law of cooling of the Newton's law type in which the relaxation time depends on the velocity autocorrelation and is then characterized by the memory function. The analysis of the temperature decay reveals the existence of an anomalous cooling in which the temperature ma...

  11. Cooling tower waste reduction

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, S.J.; Celeste, J.; Chine, R.; Scott, C.

    1998-05-01

    At Lawrence Livermore National Laboratory (LLNL), the two main cooling tower systems (central and northwest) were upgraded during the summer of 1997 to reduce the generation of hazardous waste. In 1996, these two tower systems generated approximately 135,400 lbs (61,400 kg) of hazardous sludge, which is more than 90 percent of the hazardous waste for the site annually. At both, wet decks (cascade reservoirs) were covered to block sunlight. Covering the cascade reservoirs reduced the amount of chemical conditioners (e.g. algaecide and biocide), required and in turn the amount of waste generated was reduced. Additionally, at the northwest cooling tower system, a sand filtration system was installed to allow cyclical filtering and backflushing, and new pumps, piping, and spray nozzles were installed to increase agitation. the appurtenance upgrade increased the efficiency of the cooling towers. The sand filtration system at the northwest cooling tower system enables operators to continuously maintain the cooling tower water quality without taking the towers out of service. Operational costs (including waste handling and disposal) and maintenance activities are compared for the cooling towers before and after upgrades. Additionally, the effectiveness of the sand filter system in conjunction with the wet deck covers (northwest cooling tower system), versus the cascade reservoir covers alone (south cooling tower south) is discussed. the overall expected return on investment is calculated to be in excess of 250 percent. this upgrade has been incorporated into the 1998 DOE complex-wide water conservation project being led by Sandia National Laboratory/Albuquerque.

  12. Cooling with Superfluid Helium

    CERN Document Server

    Lebrun, P

    2014-01-01

    The technical properties of helium II (‘superfluid’ helium) are presented in view of its applications to the cooling of superconducting devices, particularly in particle accelerators. Cooling schemes are discussed in terms of heat transfer performance and limitations. Large-capacity refrigeration techniques below 2 K are reviewed, with regard to thermodynamic cycles as well as process machinery. Examples drawn from existing or planned projects illustrate the presentation. Keywords: superfluid helium, cryogenics

  13. Laser cooling of solids

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, Richard I [Los Alamos National Laboratory; Sheik-bahae, Mansoor [UNM

    2008-01-01

    We present an overview of solid-state optical refrigeration also known as laser cooling in solids by fluorescence upconversion. The idea of cooling a solid-state optical material by simply shining a laser beam onto it may sound counter intuitive but is rapidly becoming a promising technology for future cryocooler. We chart the evolution of this science in rare-earth doped solids and semiconductors.

  14. Bloom syndrome radials are predominantly non-homologous and are suppressed by phosphorylated BLM.

    Science.gov (United States)

    Owen, Nichole; Hejna, James; Rennie, Scott; Mitchell, Asia; Hanlon Newell, Amy; Ziaie, Navid; Moses, Robb E; Olson, Susan B

    2014-01-01

    Biallelic mutations in BLM cause Bloom syndrome (BS), a genome instability disorder characterized by growth retardation, sun sensitivity and a predisposition to cancer. As evidence of decreased genome stability, BS cells demonstrate not only elevated levels of spontaneous sister chromatid exchanges (SCEs), but also exhibit chromosomal radial formation. The molecular nature and mechanism of radial formation is not known, but radials have been thought to be DNA recombination intermediates between homologs that failed to resolve. However, we find that radials in BS cells occur over 95% between non-homologous chromosomes, and occur non-randomly throughout the genome. BLM must be phosphorylated at T99 and T122 for certain cell cycle checkpoints, but it is not known whether these modifications are necessary to suppress radial formation. We find that exogenous BLM constructs preventing phosphorylation at T99 and T122 are not able to suppress radial formation in BS cells, but are able to inhibit SCE formation. These findings indicate that BLM functions in 2 distinct pathways requiring different modifications. In one pathway, for which the phosphorylation marks appear dispensable, BLM functions to suppress SCE formation. In a second pathway, T99 and T122 phosphorylations are essential for suppression of chromosomal radial formation, both those formed spontaneously and those formed following interstrand crosslink damage.

  15. Alternative Room Cooling System

    Directory of Open Access Journals (Sweden)

    Md. Fazle Rabbi

    2015-06-01

    Full Text Available The rapidly growing population results in an increasing demand for much more residential and commercial buildings, which leads to vertical growth of the buildings and needs proper ventilation of those buildings. Natural air ventilation system is not sufficient for conventional building structures. Hence fans and air-conditioners are must to meet the requirement of proper ventilation as well as space conditioning. Globally building sector consumes largest energy in heating, cooling, ventilation and space conditioning. This load can be minimized by the application of solar chimney and modification in building structure for heating, cooling, ventilation and space conditioning. Passive solar cooling is a subject of interest to provide cooling by using the sun, a powerful energy source. This is done for ensuring human comfort in hot climates. ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers defines Comfort as ‘that state of mind which expresses satisfaction with the thermal environment.’ The present paper describes the development of a solar passive cooling system, which can provide thermal cooling throughout the summer season in hot and humid climates. The constructed passive system works on natural convection mode of air. Such system reduces the inside temperature of up to 5°C from the atmospheric temperature. Temperature can further be reduced by the judicious use of night ventilation.

  16. Novel Integration Radial and Axial Magnetic Bearing

    Science.gov (United States)

    Blumenstock, Kenneth; Brown, Gary

    2000-01-01

    Typically, fully active magnetically suspended systems require one axial and two radial magnetic bearings. Combining radial and axial functions into a single device allows for more compact and elegant packaging. Furthermore, in the case of high-speed devices such as energy storage flywheels, it is beneficial to minimize shaft length to keep rotor mode frequencies as high as possible. Attempts have been made to combine radial and axial functionality, but with certain drawbacks. One approach requires magnetic control flux to flow through a bias magnet reducing control effectiveness, thus resulting in increased resistive losses. This approach also requires axial force producing magnetic flux to flow in a direction into the rotor laminate that is undesirable for minimizing eddy-current losses resulting in rotational losses. Another approach applies a conical rotor shape to what otherwise would be a radial heteropolar magnetic bearing configuration. However, positional non-linear effects are introduced with this scheme and the same windings are used for bias, radial, and axial control adding complexity to the controller and electronics. For this approach, the amount of axial capability must be limited. It would be desirable for an integrated radial and axial magnetic bearing to have the following characteristics; separate inputs for radial and axial control for electronics and control simplicity, all magnetic control fluxes should only flow through their respective air gaps and should not flow through any bias magnets for minimal resistive losses, be of a homopolar design to minimize rotational losses, position related non-linear effects should be minimized, and dependent upon the design parameters, be able to achieve any radial/axial force or power ratio as desired. The integrated radial and axial magnetic bearing described in this paper exhibits all these characteristics. Magnetic circuit design, design equations, and magnetic field modeling results will be presented.

  17. Novel Integrated Radial and Axial Magnetic Bearing

    Science.gov (United States)

    Blumenstock, Kenneth A.; Brown, Gary L.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    Typically, fully active magnetically suspended systems require one axial and two radial magnetic bearings. Combining radial and axial functions into a single device allows for more compact and elegant packaging. Furthermore, in the case of high-speed devices such as energy storage flywheels, it is beneficial to minimize shaft length to keep rotor mode frequencies as high as possible. Attempts have been made to combine radial and axial functionality, but with certain drawbacks. One approach requires magnetic control flux to flow through a bias magnet reducing control effectiveness, thus resulting in increased resistive losses. This approach also requires axial force producing magnetic flux to flow in a direction into the rotor laminate that is undesirable for minimizing eddy-current losses resulting in rotational losses. Another approach applies a conical rotor shape to what otherwise would be a radial heteropolar magnetic bearing configuration. However, positional non-linear effects are introduced with this scheme and the same windings are used for bias, radial, and axial control adding complexity to the controller and electronics. For this approach, the amount of axial capability must be limited. It would be desirable for an integrated radial and axial magnetic bearing to have the following characteristics, separate inputs for radial and axial control for electronics and control simplicity, all magnetic control fluxes should only flow through their respective air gaps and should not flow through any bias magnets for minimal resistive losses, be of a homopolar design to minimize rotational losses, position related non-linear effects should be minimized, and dependent upon the design parameters, be able to achieve any radial/axial force or power ratio as desired. The integrated radial and axial magnetic bearing described in this paper exhibits all these characteristics. Magnetic circuit design, design equations, and analysis results will be presented.

  18. Roughening dynamics of spontaneous radial imbibition

    CERN Document Server

    Chen, Yong-Jun

    2015-01-01

    We performed an experimental observation on the spontaneous imbibition of water in a porous media in a radial Hele-Shaw cell and confirmed Washburn's law, where r is distance and t is time. Spontaneous imbibition with a radial interface window followed scaling dynamics when the front invaded into the porous media. We found a growth exponent (\\b{eta}=0.6) that was independent of the pressure applied at the liquid inlet. The roughness exponent decreased with an increase in pressure. The roughening dynamics of two dimensional spontaneous radial imbibition obey Family-Vicsek scaling, which is different from that with a one-dimensional planar interface window.

  19. Spectral Distortion in a Radially Inhomogeneous Cosmology

    CERN Document Server

    Caldwell, R R

    2013-01-01

    The spectral distortion of the cosmic microwave background blackbody spectrum in a radially inhomogeneous spacetime, designed to exactly reproduce a LambdaCDM expansion history along the past light cone, is shown to exceed the upper bound established by COBE-FIRAS by a factor of approximately 3000. This simple observational test helps uncover a slew of pathological features that lie hidden inside the past light cone, including a radially contracting phase at decoupling and, if followed to its logical extreme, a naked singularity at the radially inhomogeneous Big Bang.

  20. Spectral distortion in a radially inhomogeneous cosmology

    Science.gov (United States)

    Caldwell, R. R.; Maksimova, N. A.

    2013-11-01

    The spectral distortion of the cosmic microwave background blackbody spectrum in a radially inhomogeneous space-time, designed to exactly reproduce a ΛCDM expansion history along the past light cone, is shown to exceed the upper bound established by COBE-FIRAS by a factor of approximately 3700. This simple observational test helps uncover a slew of pathological features that lie hidden inside the past light cone, including a radially contracting phase at decoupling and, if followed to its logical extreme, a naked singularity at the radially inhomogeneous big bang.

  1. Discontinuity effects on radial cavity transmission lines

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, D.B.

    1979-04-01

    Pulse propagation in radial cavity transmission lines such as those found on a radial line accelerator is considered. Specifically, the effects of discontinuities along the line are examined in detail. It is found that previous analyses of such effects have been incorrect, and here two alternate solution techniques are presented. Depending upon the parameters of such a radial line, the discontinuity effects considered here may or may not be significant; however, if they are significant, it is recommended that the alternate solution techniques presented here be used.

  2. Comparing Social Stories™ to Cool versus Not Cool

    Science.gov (United States)

    Leaf, Justin B.; Mitchell, Erin; Townley-Cochran, Donna; McEachin, John; Taubman, Mitchell; Leaf, Ronald

    2016-01-01

    In this study we compared the cool versus not cool procedure to Social Stories™ for teaching various social behaviors to one individual diagnosed with autism spectrum disorder. The researchers randomly assigned three social skills to the cool versus not cool procedure and three social skills to the Social Stories™ procedure. Naturalistic probes…

  3. Muon Tracking Studies in a Skew Parametric Resonance Ionization Cooling Channel

    Energy Technology Data Exchange (ETDEWEB)

    Sy, Amy [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Afanaciev, Andre [George Washington Univ., Washington, DC (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Johnson, Rolland [Muons, Inc., Batavia, IL (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    Skew Parametric-resonance Ionization Cooling (SPIC) is an extension of the Parametric-resonance Ionization Cooling (PIC) framework that has previously been explored as the final 6D cooling stage of a high-luminosity muon collider. The addition of skew quadrupoles to the PIC magnetic focusing channel induces coupled dynamic behavior of the beam that is radially periodic. The periodicity of the radial motion allows for the avoidance of unwanted resonances in the horizontal and vertical transverse planes, while still providing periodic locations at which ionization cooling components can be implemented. A first practical implementation of the magnetic field components required in the SPIC channel is modeled in MADX. Dynamic features of the coupled correlated optics with and without induced parametric resonance are presented and discussed.

  4. Measuring the coolness of interactive products: the COOL questionnaire

    DEFF Research Database (Denmark)

    Bruun, Anders; Raptis, Dimitrios; Kjeldskov, Jesper

    2016-01-01

    characteristics. These were used to create an initial pool of question items and 2236 participants were asked to assess 16 mobile devices. By performing exploratory and confirmatory factor analyses, we identified three factors that can measure the perceived inner coolness of interactive products: desirability...... is the COOL questionnaire. We based the creation of the questionnaire on literature suggesting that perceived coolness is decomposed to outer cool (the style of a product) and inner cool (the personality characteristics assigned to it). In this paper, we focused on inner cool, and we identified 11 inner cool...

  5. Laser cooling of a diatomic molecule

    CERN Document Server

    Shuman, E S; DeMille, D

    2011-01-01

    It has been roughly three decades since laser cooling techniques produced ultracold atoms, leading to rapid advances in a vast array of fields. Unfortunately laser cooling has not yet been extended to molecules because of their complex internal structure. However, this complexity makes molecules potentially useful for many applications. For example, heteronuclear molecules possess permanent electric dipole moments which lead to long-range, tunable, anisotropic dipole-dipole interactions. The combination of the dipole-dipole interaction and the precise control over molecular degrees of freedom possible at ultracold temperatures make ultracold molecules attractive candidates for use in quantum simulation of condensed matter systems and quantum computation. Also ultracold molecules may provide unique opportunities for studying chemical dynamics and for tests of fundamental symmetries. Here we experimentally demonstrate laser cooling of the molecule strontium monofluoride (SrF). Using an optical cycling scheme re...

  6. Radial Velocity Fluctuations of RZ Psc

    Science.gov (United States)

    Potravnov, I. S.; Gorynya, N. A.; Grinin, V. P.; Minikulov, N. Kh.

    2014-12-01

    The behavior of the radial velocity of the UX Ori type star RZ Psc is studied. The existence of an inner cavity with a radius of about 0.7 a.u. in the circumstellar disk of this star allows to suggest the presence of a companion. A study of the radial velocity of RZ Psc based on our own measurements and published data yields no periodic component in its variability. The two most accurate measurements of V r , based on high resolution spectra obtained over a period of three months, show that the radial velocity is constant over this time interval to within 0.5 km/s. This imposes a limit of M p ≤10 M Jup on the mass of the hypothetical companion. Possible reasons for the observed strong fluctuations in the radial velocity of this star are discussed.

  7. An unusual cause of radial nerve palsy

    Institute of Scientific and Technical Information of China (English)

    Hemendra Kumar Agrawal; Vipin Khatkar; Mohit Garg; Balvinder Singh; Ashish Jaiman; Vinod Kumar Sharma

    2014-01-01

    Neurapraxia frequently occurs following traction injury to the nerve intraoperatively,leading to radial nerve palsy which usually recovers in 5-30 weeks.In our case,we had operated a distal one-third of humeral shaft fracture and fixed it with 4.5 mm limited contact dynamic compression plate.The distal neurovascular status of the limb was assessed postoperatively in the recovery room and was found to be intact and all the sensory-motor functions of the radial nerve were normal.On the second postoperative day,following the suction drain removal and dressing,patient developed immediate radial nerve palsy along with wrist drop.We reviewed the literature and found no obvious cause for the nerve palsy and concluded that it was due to traction injury to the radial nerve while removing the suction drain in negative pressure.

  8. How to distinguish Hybrids from Radial Quarkonia

    CERN Document Server

    Close, Francis Edwin; Close, Frank E; Page, Philip R.

    1997-01-01

    We present arguments that reinforce the hybrid interpretation of pi(1800) and we establish that the rho(1450) and the omega(1420) can be interpreted as radial-hybrid mixtures. Some questions for future experiments are raised.

  9. Radial pseudoaneurysm following diagnostic coronary angiography

    Directory of Open Access Journals (Sweden)

    Shankar Laudari

    2015-06-01

    Full Text Available The radial artery access has gained popularity as a method of diagnostic coronary catheterization compared to femoral artery puncture in terms of vascular complications and early ambulation. However, very rare complication like radial artery pseudoaneurysm may occur following cardiac catheterization which may give rise to serious consequences. Here, we report a patient with radial pseudoaneurysm following diagnostic coronary angiography. Adequate and correct methodology of compression of radial artery following puncture for maintaining hemostasis is the key to prevention.DOI: http://dx.doi.org/10.3126/jcmsn.v10i3.12776 Journal of College of Medical Sciences-Nepal, 2014, Vol-10, No-3, 48-50

  10. Solutions of relativistic radial quasipotential equations

    Energy Technology Data Exchange (ETDEWEB)

    Minh, V.X.; Kadyshevskii, V.G.; Zhidkov, E.P.

    1985-11-01

    A systematic approach to the investigation of relativistic radial quasipotential equations is developed. The quasipotential equations can be interpreted either as linear equations in finite differences of fourth and second orders, respectively, or as differential equations of infinite order.

  11. Guidance cue for cortical radial migration discovered

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The regulatory mechanism for neuronal migration in the developing cortex is a major unsolved problem in developmental neurobiology. It is generally accepted that the migration of newborn pyramidal neurons from the ventricular zone toward upper cortical layers is guided by radial glial fibers in the developing cortex, and that the laminar structure of the cortex is formed through regulated attachment and detachment of migrating neurons with radial glial fibers.

  12. Electromechanical properties of radial active magnetic bearings

    OpenAIRE

    Antila, Matti

    1998-01-01

    Nonideal properties of the electromagnetic actuators in radial active magnetic bearings are studied. The two dimensional nonlinear stationary finite element method is used to determine the linearised parameters of a radial active magnetic bearing. The method is verified on two test machines. The accuracy is 10-15 % in the magnetic saturation region. The effect of magnetic saturation on the bearing dynamics is studied based on the root locus diagrams of the closed loop system. These diagrams s...

  13. Electromagnetically-induced-transparency ground-state cooling of long ion strings

    Science.gov (United States)

    Lechner, Regina; Maier, Christine; Hempel, Cornelius; Jurcevic, Petar; Lanyon, Ben P.; Monz, Thomas; Brownnutt, Michael; Blatt, Rainer; Roos, Christian F.

    2016-05-01

    Electromagnetically-induced-transparency (EIT) cooling is a ground-state cooling technique for trapped particles. EIT offers a broader cooling range in frequency space compared to more established methods. In this work, we experimentally investigate EIT cooling in strings of trapped atomic ions. In strings of up to 18 ions, we demonstrate simultaneous ground-state cooling of all radial modes in under 1 ms. This is a particularly important capability in view of emerging quantum simulation experiments with large numbers of trapped ions. Our analysis of the EIT cooling dynamics is based on a technique enabling single-shot measurements of phonon numbers, by rapid adiabatic passage on a vibrational sideband of a narrow transition.

  14. The definition of cool

    Energy Technology Data Exchange (ETDEWEB)

    Nichiporuk, A.

    2005-05-01

    A new air cooling system at Agnico-Eagle's LaRonde mine, located in the Abitibi Region of Quebec is described. The new system serves a mine operating at 7,250 plus feet level. The system is installed at the surface; it utilizes ammonia to cool water, which cools the air. The system consists of four compressors which lower the temperature of the ammonia to minus 2 degrees C. Water, which at this temperature is 14 degrees, and ammonia pass through a plate heat exchanger simultaneously, however, without coming into contact with each other. The heat transfer that occurs causes the water's temperature to drop to 2 degrees C. The total volume of water cooled is 220 litres per second. The system is capable of reducing 636,000 cfm of air from 30 degrees C to 6 degrees C, to which 214,000 cfm of non-cooled air is added. This mixture, which is maintained at approximately 8 degrees C throughout the summer season, is sent underground to the deepest parts of the mine. The system runs from June to September, depending on the weather. In the evenings, when the temperature dips to around four to five degrees C, the water is shut down and side doors are opened to prevent the water from freezing.

  15. Aspects of Household Cooling Technology

    OpenAIRE

    Mrzyglod, Matthias; Holzer, Stefan

    2014-01-01

    Actually available household cooling appliances in the highest efficiency class may consume less then 10W average electrical power. To achieve such power consumptions special challenges for the cooling system had to overcome. The related cooling system design has to consider several effects, which arise from the corresponding low cooling capacity demand, start/stop cycles and additional power consumptions by control accessories. The lecture provides symptomatic aspects of cooling technology, ...

  16. Comparison between Cooling Rate Dependence of Macroscopic and Microscopic Quantities in Simulated Aluminium Glass

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-Song; ZHU Zhen-Gang

    2000-01-01

    Constant-pressure molecular dynamics simulations and an analysis of the local atomic structures have been performed to study the cooling rate dependence of some macroscopic and microscopic quantities in aluminium glass. Macroscopic quantities, enthalpy and density, see an observable but small dependence on the cooling rate. Icosahedral ordering units exhibit strong cooling rate dependence, which is responsible for the dependence of the enthalpy and the density on the cooling rate; while the almost independence of some microstructural units such as the 1541, 1431 and 1421 pairs of the cooling rate may lead to a small dependence of the enthalpy and the density on the cooling rate.

  17. Doppler cooling a microsphere

    CERN Document Server

    Barker, P F

    2010-01-01

    Doppler cooling the center-of-mass motion of an optically levitated microsphere via the velocity dependent scattering force from narrow whispering gallery mode (WGM) resonances is described. Light that is red detuned from the WGM resonance can be used to damp the center-of-mass motion in a process analogous to the Doppler cooling of atoms. Leakage of photons out of the microsphere when the incident field is near resonant with the narrow WGM resonance acts to damp the motion of the sphere. The scattering force is not limited by saturation, but can be controlled by the incident power. Cooling times on the order of seconds are calculated for a 20 micron diameter silica microsphere trapped within optical tweezers, with a Doppler temperature limit in the microKelvin regime.

  18. Natural radiative cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.

    1979-01-01

    Natural radiative cooling at night was measured based on the surface-radiation spectrum after the heat balance of the surface exposed to the sun had been reradiated. A concept equivalent to the sky temperature and a concept useful for obtaining the net heat flux are discussed. The highest possible equilibrium temperature of the selective surface can be lowered; however, how to apply this practically is not yet known. A simple radiator, completely enclosed by a transparent screen, can produce a significant and inexpensive cooling effect. The results of experiments carried out in an area such as Padua, Italy, where the climate is not suitable for cooling purposes can still be predicted theoretically. The possibility of using the collector for heat collection during the day and as a radiator at night is indicated.

  19. Clean cooling; Saubere Kuehlung

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-07-01

    The round hybrid cooling towers which Balcke-Duerr GmbH is currently building for the 550-MW-IGCC-power-station of a refinery project on Sardinia have to meet particularly stringent requirements as seawater is used for cooling. The advantages are: Avoidance of visible plume with minimal energy consumption, optimal plume exit velocity and discharge, greatest possible stability of the plume column, avoidance of interference and recirculation, high operating reliability of the cooling tower. (orig.) [Deutsch] Derzeit werden die Kuehltuerme fuer ein 550-MW-IGCC-Kraftwerk einer Raffinierie auf Sardinien errichtet. Die Anforderungen an die Technik sind hoch, denn gekuehlt wird mit Seewasser. Zum Einsatz kommen Hybridrundkuehltuerme der Balcke-Duerr GmbH, Ratingen. Damit setzt das Unternehmen diesen Typ erstmals ausserhalb von Deutschland ein. (orig.)

  20. Monitoring Cray Cooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Don E [ORNL; Ezell, Matthew A [ORNL; Becklehimer, Jeff [Cray, Inc.; Donovan, Matthew J [ORNL; Layton, Christopher C [ORNL

    2014-01-01

    While sites generally have systems in place to monitor the health of Cray computers themselves, often the cooling systems are ignored until a computer failure requires investigation into the source of the failure. The Liebert XDP units used to cool the Cray XE/XK models as well as the Cray proprietary cooling system used for the Cray XC30 models provide data useful for health monitoring. Unfortunately, this valuable information is often available only to custom solutions not accessible by a center-wide monitoring system or is simply ignored entirely. In this paper, methods and tools used to harvest the monitoring data available are discussed, and the implementation needed to integrate the data into a center-wide monitoring system at the Oak Ridge National Laboratory is provided.

  1. Research on Cooling Effectiveness in Stepped Slot Film Cooling Vane

    Institute of Scientific and Technical Information of China (English)

    LI Yulong; WU Hong; ZHOU Feng; RONG Chengjun

    2016-01-01

    As one of the most important developments in air cooling technology for hot parts of the aero-engine,film cooling technology has been widely used.Film cooling hole structure exists mainly in areas that have high temperature,uneven cooling effectiveness issues when in actual use.The first stage turbine vanes of the aero-engine consume the largest portion of cooling air,thereby the research on reducing the amount of cooling air has the greatest potential.A new stepped slot film cooling vane with a high cooling effectiveness and a high cooling uniformity was researched initially.Through numerical methods,the affecting factors of the cooling effectiveness of a vane with the stepped slot film cooling structure were researched.This paper focuses on the cooling effectiveness and the pressure loss in different blowing ratio conditions,then the most reasonable and scientific structure parameter can be obtained by analyzing the results.The results show that 1.0 mm is the optimum slot width and 10.0 is the most reasonable blowing ratio.Under this condition,the vane achieved the best cooling result and the highest cooling effectiveness,and also retained a low pressure loss.

  2. Anomalous law of cooling.

    Science.gov (United States)

    Lapas, Luciano C; Ferreira, Rogelma M S; Rubí, J Miguel; Oliveira, Fernando A

    2015-03-14

    We analyze the temperature relaxation phenomena of systems in contact with a thermal reservoir that undergoes a non-Markovian diffusion process. From a generalized Langevin equation, we show that the temperature is governed by a law of cooling of the Newton's law type in which the relaxation time depends on the velocity autocorrelation and is then characterized by the memory function. The analysis of the temperature decay reveals the existence of an anomalous cooling in which the temperature may oscillate. Despite this anomalous behavior, we show that the variation of entropy remains always positive in accordance with the second law of thermodynamics.

  3. Anomalous law of cooling

    Science.gov (United States)

    Lapas, Luciano C.; Ferreira, Rogelma M. S.; Rubí, J. Miguel; Oliveira, Fernando A.

    2015-03-01

    We analyze the temperature relaxation phenomena of systems in contact with a thermal reservoir that undergoes a non-Markovian diffusion process. From a generalized Langevin equation, we show that the temperature is governed by a law of cooling of the Newton's law type in which the relaxation time depends on the velocity autocorrelation and is then characterized by the memory function. The analysis of the temperature decay reveals the existence of an anomalous cooling in which the temperature may oscillate. Despite this anomalous behavior, we show that the variation of entropy remains always positive in accordance with the second law of thermodynamics.

  4. Superconductor rotor cooling system

    Science.gov (United States)

    Gamble, Bruce B.; Sidi-Yekhlef, Ahmed; Schwall, Robert E.; Driscoll, David I.; Shoykhet, Boris A.

    2002-01-01

    A system for cooling a superconductor device includes a cryocooler located in a stationary reference frame and a closed circulation system external to the cryocooler. The closed circulation system interfaces the stationary reference frame with a rotating reference frame in which the superconductor device is located. A method of cooling a superconductor device includes locating a cryocooler in a stationary reference frame, and transferring heat from a superconductor device located in a rotating reference frame to the cryocooler through a closed circulation system external to the cryocooler. The closed circulation system interfaces the stationary reference frame with the rotating reference frame.

  5. A Cool Emperor Penguin

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    哇,这只帝企鹅的胸前居然有个心形!It’s cool!(乐天:没错,它的胸前少了这幺撮毛,应该会感觉挺凉快的)cool在这里可不是“凉快”的意思,而是“酷.帅气”的意思。我们《英语大王》的英文名字就叫English Cool Kids哦!(乐天拿出一副墨镜戴上:

  6. Rapid cooled lens cell

    Science.gov (United States)

    Stubbs, David M.; Hsu, Ike C.

    1991-12-01

    This paper describes the optomechanical design, thermal analysis, fabrication, and test evaluation processes followed in developing a rapid cooled, infrared lens cell. Thermal analysis was the key engineering discipline exercised in the design phase. The effect of thermal stress on the lens, induced by rapid cooling of the lens cell, was investigated. Features of this lens cell that minimized the thermal stress will be discussed in a dedicated section. The results of thermal analysis on the selected lens cell design and the selection of the flow channel design in the heat exchanger will be discussed. Throughout the paper engineering drawings, illustrations, analytical results, and photographs of actual hardware are presented.

  7. Gas cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1972-06-01

    Although most of the development work on fast breeder reactors has been devoted to the use of liquid metal cooling, interest has been expressed for a number of years in alternative breeder concepts using other coolants. One of a number of concepts in which interest has been retained is the Gas-Cooled Fast Reactor (GCFR). As presently envisioned, it would operate on the uranium-plutonium mixed oxide fuel cycle, similar to that used in the Liquid Metal Fast Breeder Reactor (LMFBR), and would use helium gas as the coolant.

  8. On the calculation of x-ray scattering signals from pairwise radial distribution functions

    DEFF Research Database (Denmark)

    Dohn, Asmus Ougaard; Biasin, Elisa; Haldrup, Kristoffer;

    2015-01-01

    We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any possi...

  9. RADIAL DISTRIBUTION FUNCTION OF cis-1,4-POLYBUTADIENE BY ELECTRON DIFFRACTION

    Institute of Scientific and Technical Information of China (English)

    ZHOU Enle; KAN Xianglan; ZHAO Xiaoguang

    1983-01-01

    The interatomic distance function of rareearth catalyzed cis-1,4-polybutadiene was studied by radial distribution function (RDF) derived from electron diffraction. Two intramolecular peaks and three intermolecular peaks have been found on the RDF. The appearance of such a number of intermolecular maxima on the RDF can be explained by the local parallel packing of long molecular chains of the amorphous polymers.

  10. Measure Guideline: Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Springer, D. [Alliance for Residential Building Innovation (ARBI), David, CA (United States); Dakin, B. [Alliance for Residential Building Innovation (ARBI), David, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), David, CA (United States)

    2012-04-01

    The purpose of this measure guideline is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

  11. Cooling of Neutron Stars

    Directory of Open Access Journals (Sweden)

    Grigorian H.

    2010-10-01

    Full Text Available We introduce the theoretical basis for modeling the cooling evolution of compact stars starting from Boltzmann equations in curved space-time. We open a discussion on observational verification of different neutron star models by consistent statistics. Particular interest has the question of existence of quark matter deep inside of compact object, which has to have a specific influence on the cooling history of the star. Besides of consideration of several constraints and features of cooling evolution, which are susceptible of being critical for internal structure of hot compact stars we have introduced a method of extraction of the mass distribution of the neutron stars from temperature and age data. The resulting mass distribution has been compared with the one suggested by supernove simulations. This method can be considered as an additional checking tool for the consistency of theoretical modeling of neutron stars. We conclude that the cooling data allowed existence of neutron stars with quark cores even with one-flavor quark matter.

  12. Elementary stochastic cooling

    Energy Technology Data Exchange (ETDEWEB)

    Tollestrup, A.V.; Dugan, G

    1983-12-01

    Major headings in this review include: proton sources; antiproton production; antiproton sources and Liouville, the role of the Debuncher; transverse stochastic cooling, time domain; the accumulator; frequency domain; pickups and kickers; Fokker-Planck equation; calculation of constants in the Fokker-Planck equation; and beam feedback. (GHT)

  13. ELECTRON COOLING FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI,I.

    2001-05-13

    The Accelerator Collider Department (CAD) at Brookhaven National Laboratory is operating the Relativistic Heavy Ion Collider (RHIC), which includes the dual-ring, 3.834 km circumference superconducting collider and the venerable AGS as the last part of the RHIC injection chain. CAD is planning on a luminosity upgrade of the machine under the designation RHIC II. One important component of the RHIC II upgrade is electron cooling of RHIC gold ion beams. For this purpose, BNL and the Budker Institute of Nuclear Physics in Novosibirsk entered into a collaboration aimed initially at the development of the electron cooling conceptual design, resolution of technical issues, and finally extend the collaboration towards the construction and commissioning of the cooler. Many of the results presented in this paper are derived from the Electron Cooling for RHIC Design Report [1], produced by the, BINP team within the framework of this collaboration. BNL is also collaborating with Fermi National Laboratory, Thomas Jefferson National Accelerator Facility and the University of Indiana on various aspects of electron cooling.

  14. The lumping of heat transfer parameters in cooled packed beds: effect of the bed entry

    NARCIS (Netherlands)

    Westerink, E.J.; Gerner, J.W.; Gerner, J.W.; Westerterp, K.R.; van der Wal, S.

    1993-01-01

    The lumping of the heat transfer parameters of the one- and the two-dimensional pseudo-homogeneous model of a cooled fixed bed were compared. It appeared that the lumping of the two-dimensional parameters, being the effective radial conductivity h-eff and the heat transfer coefficient at the wall (a

  15. Determination of effective heat transport coefficients for wall-cooled packed beds

    NARCIS (Netherlands)

    Borkink, J.G.H.; Borkink, J.G.H.; Westerterp, K.R.

    1992-01-01

    The influence is studied of several assumptions, often made in literature, on the values for the effective radial heat conductivity, wall heat transfer coefficient and overall heat transfer coefficient, as obtained from experiments in wall-cooled packed beds without a chemical reaction. Especially t

  16. The cool supergiant population of the massive young star cluster RSGC1

    NARCIS (Netherlands)

    Davies, B.; Figer, D.F.; Law, C.J.; Kudritzki, R.-P.; Najarro, F.; Herrero, A.; MacKenty, J.W.

    2008-01-01

    We present new high-resolution near-IR spectroscopy and OH maser observations to investigate the population of cool luminous stars of the young massive Galactic cluster RSGC1. Using the 2.293 mu m CO band-head feature, we make high-precision radial velocity measurements of 16 of the 17 candidate red

  17. Late radial head dislocation with radial head fracture and ulnar plastic deformation

    NARCIS (Netherlands)

    Heinrich, Stephen D.; Butler, R. Allen

    Type 11 Monteggia lesion equivalents produced by plastic deformation of the ulna are rare. Radial head fractures in skeletally immature patients are also uncommon. We report a late presentation of a Type 11 Monteggia equivalent injury with a fracture of the radial head and neck and plastic

  18. Molecular dynamics simulation of amorphous SiO2 nanoparticles.

    Science.gov (United States)

    Hoang, Vo Van

    2007-11-08

    Molecular dynamics simulation of amorphous SiO2 spherical nanoparticles has been carried out in a model with different sizes, 2, 4, and 6 nm, under non-periodic boundary conditions. We use the pair interatomic potentials which have weak Coulomb interaction and Morse type short-range interaction. Models have been obtained by cooling from the melt via molecular dynamics (MD) simulation. Structural properties of amorphous nanoparticles obtained at 350 K have been studied via partial radial distribution functions (PRDFs), mean interatomic distances, coordination numbers, and bond-angle distributions, which are compared with those observed in the bulk. Calculations of the radial density profile in nanoparticles show the tendency of oxygen to concentrate at the surface as observed previously in other amorphous clusters or thin films. Size effects on structure of nanosized models are significant. The calculations show that if the size is larger than 4 nm, amorphous SiO2 nanoparticles have a distorted tetrahedral network structure with the mean coordination number ZSi-O approximately 4.0 and ZO-Si approximately 2.0 like those observed in the bulk. Surface structure, surface energy, and glass transition temperature of SiO2 nanoparticles have been obtained and presented.

  19. Cooling system for rotating machine

    Science.gov (United States)

    Gerstler, William Dwight; El-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Alexander, James Pellegrino; Quirion, Owen Scott; Palafox, Pepe; Shen, Xiaochun; Salasoo, Lembit

    2011-08-09

    An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

  20. Physical mechanism determining the radial electric field and its radial structure in a toroidal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ida, Katsumi; Miura, Yukitoshi; Itoh, Sanae [and others

    1994-10-01

    Radial structures of plasma rotation and radial electric field are experimentally studied in tokamak, heliotron/torsatron and stellarator devices. The perpendicular and parallel viscosities are measured. The parallel viscosity, which is dominant in determining the toroidal velocity in heliotron/torsatron and stellarator devices, is found to be neoclassical. On the other hand, the perpendicular viscosity, which is dominant in dictating the toroidal rotation in tokamaks, is anomalous. Even without external momentum input, both a plasma rotation and a radial electric field exist in tokamaks and heliotrons/torsatrons. The observed profiles of the radial electric field do not agree with the theoretical prediction based on neoclassical transport. This is mainly due to the existence of anomalous perpendicular viscosity. The shear of the radial electric field improves particle and heat transport both in bulk and edge plasma regimes of tokamaks. (author) 95 refs.

  1. Manufacturing of Precision Forgings by Radial Forging

    Science.gov (United States)

    Wallner, S.; Harrer, O.; Buchmayr, B.; Hofer, F.

    2011-01-01

    Radial forging is a multi purpose incremental forging process using four tools on the same plane. It is widely used for the forming of tool steels, super alloys as well as titanium- and refractory metals. The range of application goes from reducing the diameters of shafts, tubes, stepped shafts and axels, as well as for creating internal profiles for tubes in Near-Net-Shape and Net-Shape quality. Based on actual development of a weight optimized transmission input shaft, the specific features of radial forging technology is demonstrated. Also a Finite Element Model for the simulation of the process is shown which leads to reduced pre-processing effort and reduced computing time compared to other published simulation methods for radial forging. The finite element model can be applied to quantify the effects of different forging strategies.

  2. Non radial motions in a CDM model

    CERN Document Server

    Gambera, M

    1998-01-01

    We show how non-radial motions, originating in the outskirts of clusters of galaxies, may reduce the discrepancy between the Cold Dark Matter (CDM) predicted X-ray temperature distribution function of clusters of galaxies and the observed one and also the discrepancy between the CDM predicted two-point correlation function of clusters of galaxies and that observed. We compare Edge et al. (1990) and Henry & Arnaud (1991) data with the distribution function of X-ray temperature, calculated using Press- Schechter's (1974 - hereafter PS) theory and Evrard's (1990) prescriptions for the mass-temperature relation and taking account of the non-radial motions originating from the gravitational interaction of the quadrupole moment of the protocluster with the tidal field of the matter of the neighboring protostructures. We find that the model produces a reasonable clusters temperature distribution. We compare the two-point cluster correlation function which takes account of the non-radial motions both with that ob...

  3. Dispersion-free radial transmission lines

    Science.gov (United States)

    Caporaso, George J [Livermore, CA; Nelson, Scott D [Patterson, CA

    2011-04-12

    A dispersion-free radial transmission line ("DFRTL") preferably for linear accelerators, having two plane conductors each with a central hole, and an electromagnetically permeable material ("EPM") between the two conductors and surrounding a channel connecting the two holes. At least one of the material parameters of relative magnetic permeability, relative dielectric permittivity, and axial width of the EPM is varied as a function of radius, so that the characteristic impedance of the DFRTL is held substantially constant, and pulse transmission therethrough is substantially dispersion-free. Preferably, the EPM is divided into concentric radial sections, with the varied material parameters held constant in each respective section but stepwise varied between sections as a step function of the radius. The radial widths of the concentric sections are selected so that pulse traversal time across each section is the same, and the varied material parameters of the concentric sections are selected to minimize traversal error.

  4. Cloaking and Magnifying Using Radial Anisotropy

    CERN Document Server

    Kettunen, Henrik; Sihvola, Ari

    2013-01-01

    This paper studies the electrostatic responses of a polarly radially anisotropic cylinder and a spherically radially anisotropic sphere. For both geometries, the permittivity components differ from each other in the radial and tangential directions. We show that choosing the ratio between these components in a certain way, these rather simple structures can be used in cloaking dielectric inclusions with arbitrary permittivity and shape in the quasi-static limit. For an ideal cloak, the contrast between the permittivity components has to tend to infinity. However, only positive permittivity values are required and a notable cloaking effect can already be observed with relatively moderate permittivity contrasts. Furthermore, we show that the polarly anisotropic cylindrical shell has a complementary capability of magnifying the response of an inner cylinder.

  5. Image scanning microscopy with radially polarized light

    Science.gov (United States)

    Xiao, Yun; Zhang, Yunhai; Wei, Tongda; Huang, Wei; Shi, Yaqin

    2017-03-01

    In order to improve the resolution of image scanning microscopy, we present a method based on image scanning microscopy and radially polarized light. According to the theory of image scanning microscopy, we get the effective point spread function of image scanning microscopy with the longitudinal component of radially polarized light and a 1 AU detection area, and obtain imaging results of the analyzed samples using this method. Results show that the resolution can be enhanced by 7% compared with that in image scanning microscopy with circularly polarized light, and is 1.54-fold higher than that in confocal microscopy with a pinhole of 1 AU. Additionally, the peak intensity of ISM is 1.54-fold higher than that of a confocal microscopy with a pinhole of 1 AU. In conclusion, the combination of the image scanning microscopy and the radially polarized light could improve the resolution, and it could realize high-resolution and high SNR imaging at the same time.

  6. Radial anisotropy ambient noise tomography of volcanoes

    Science.gov (United States)

    Mordret, Aurélien; Rivet, Diane; Shapiro, Nikolai; Jaxybulatov, Kairly; Landès, Matthieu; Koulakov, Ivan; Sens-Schönfelder, Christoph

    2016-04-01

    The use of ambient seismic noise allows us to perform surface-wave tomography of targets which could hardly be imaged by other means. The frequencies involved (~ 0.5 - 20 s), somewhere in between active seismic and regular teleseismic frequency band, make possible the high resolution imaging of intermediate-size targets like volcanic edifices. Moreover, the joint inversion of Rayleigh and Love waves dispersion curves extracted from noise correlations allows us to invert for crustal radial anisotropy. We present here the two first studies of radial anisotropy on volcanoes by showing results from Lake Toba Caldera, a super-volcano in Indonesia, and from Piton de la Fournaise volcano, a hot-spot effusive volcano on the Réunion Island (Indian Ocean). We will see how radial anisotropy can be used to infer the main fabric within a magmatic system and, consequently, its dominant type of intrusion.

  7. Size effect in the melting and freezing behaviors of Al/Ti core-shell nanoparticles using molecular dynamics simulations

    Science.gov (United States)

    Jin-Ping, Zhang; Yang-Yang, Zhang; Er-Ping, Wang; Cui-Ming, Tang; Xin-Lu, Cheng; Qiu-Hui, Zhang

    2016-03-01

    The thermal stability of Ti@Al core/shell nanoparticles with different sizes and components during continuous heating and cooling processes is examined by a molecular dynamics simulation with embedded atom method. The thermodynamic properties and structure evolution during continuous heating and cooling processes are investigated through the characterization of the potential energy, specific heat distribution, and radial distribution function (RDF). Our study shows that, for fixed Ti core size, the melting temperature decreases with Al shell thickness, while the crystallizing temperature and glass formation temperature increase with Al shell thickness. Diverse melting mechanisms have been discovered for different Ti core sized with fixed Al shell thickness nanoparticles. The melting temperature increases with the Ti core radius. The trend agrees well with the theoretical phase diagram of bimetallic nanoparticles. In addition, the glass phase formation of Al-Ti nanoparticles for the fast cooling rate of 12 K/ps, and the crystal phase formation for the low cooling rate of 0.15 K/ps. The icosahedron structure is formed in the frozen 4366 Al-Ti atoms for the low cooling rate. Project supported by the National Natural Science Foundation of China (Grant No. 21401064), the Science & Technology Development Program of Henan Province, China (Grant No. 142300410282), and the Program of Henan Educational Committee, China (Grant No. 13B140986).

  8. Sorption cooling: a valid extension to passive cooling

    NARCIS (Netherlands)

    Doornink, D.J.; Burger, J.F.; Brake, ter H.J.M.

    2008-01-01

    Passive cooling has shown to be a very dependable cryogenic cooling method for space missions. Several missions employ passive radiators to cool down their delicate sensor systems for many years, without consuming power, without exporting vibrations or producing electromagnetic interference. So for

  9. Comments on Ionization Cooling Channel Characteristics

    CERN Document Server

    Neuffer, David

    2013-01-01

    Ionization cooling channels with a wide variety of characteristics and cooling properties are being developed. These channels can produce cooling performances that are largely consistent with the ionization cooling theory developed previously. In this paper we review ionization cooling theory, discuss its application to presently developing cooling channels, and discuss criteria for optimizing cooling.

  10. Comments on Ionization Cooling Channel Characteristics

    OpenAIRE

    Neuffer, David

    2013-01-01

    Ionization cooling channels with a wide variety of characteristics and cooling properties are being developed. These channels can produce cooling performances that are largely consistent with the ionization cooling theory developed previously. In this paper we review ionization cooling theory, discuss its application to presently developing cooling channels, and discuss criteria for optimizing cooling.

  11. Concepts of radial and angular kinetic energies

    DEFF Research Database (Denmark)

    Dahl, Jens Peder; Schleich, W.P.

    2002-01-01

    We consider a general central-field system in D dimensions and show that the division of the kinetic energy into radial and angular parts proceeds differently in the wave-function picture and the Weyl-Wigner phase-space picture, Thus, the radial and angular kinetic energies are different quantiti...... in the two pictures, containing different physical information, but the relation between them is well defined. We discuss this relation and illustrate its nature by examples referring to a free particle and to a ground-state hydrogen atom....

  12. Precise Near-Infrared Radial Velocities

    CERN Document Server

    Plavchan, Peter; Gagne, Jonathan; Furlan, Elise; Brinkworth, Carolyn; Bottom, Michael; Tanner, Angelle; Anglada-Escude, Guillem; White, Russel; Davison, Cassy; Mills, Sean; Beichman, Chas; Johnson, John Asher; Ciardi, David; Wallace, Kent; Mennesson, Bertrand; Vasisht, Gautam; Prato, Lisa; Kane, Stephen; Crawford, Sam; Crawford, Tim; Sung, Keeyoon; Drouin, Brian; Lin, Sean; Leifer, Stephanie; Catanzarite, Joe; Henry, Todd; von Braun, Kaspar; Walp, Bernie; Geneser, Claire; Ogden, Nick; Stufflebeam, Andrew; Pohl, Garrett; Regan, Joe

    2016-01-01

    We present the results of two 2.3 micron near-infrared radial velocity surveys to detect exoplanets around 36 nearby and young M dwarfs. We use the CSHELL spectrograph (R ~46,000) at the NASA InfraRed Telescope Facility, combined with an isotopic methane absorption gas cell for common optical path relative wavelength calibration. We have developed a sophisticated RV forward modeling code that accounts for fringing and other instrumental artifacts present in the spectra. With a spectral grasp of only 5 nm, we are able to reach long-term radial velocity dispersions of ~20-30 m/s on our survey targets.

  13. Radial excitations of current-carrying vortices

    Science.gov (United States)

    Hartmann, Betti; Michel, Florent; Peter, Patrick

    2017-04-01

    We report on the existence of a new type of cosmic string solutions in the Witten model with U (1) × U (1) symmetry. These solutions are superconducting with radially excited condensates that exist for both gauged and ungauged currents. Our results suggest that these new configurations can be macroscopically stable, but microscopically unstable to radial perturbations. Nevertheless, they might have important consequences for the network evolution and particle emission. We discuss these effects and their possible signatures. We also comment on analogies with non-relativistic condensed matter systems where these solutions may be observable.

  14. Radial Acceleration Relation in Rotationally Supported Galaxies

    Science.gov (United States)

    McGaugh, Stacy S.; Lelli, Federico; Schombert, James M.

    2016-11-01

    We report a correlation between the radial acceleration traced by rotation curves and that predicted by the observed distribution of baryons. The same relation is followed by 2693 points in 153 galaxies with very different morphologies, masses, sizes, and gas fractions. The correlation persists even when dark matter dominates. Consequently, the dark matter contribution is fully specified by that of the baryons. The observed scatter is small and largely dominated by observational uncertainties. This radial acceleration relation is tantamount to a natural law for rotating galaxies.

  15. Five Lectures on Radial Basis Functions

    DEFF Research Database (Denmark)

    Powell, Mike J.D.

    2005-01-01

    Professor Mike J. D. Powell spent three weeks at IMM in November - December 2004. During the visit he gave five lectures on radial basis functions. These notes are a TeXified version of his hand-outs, made by Hans Bruun Nielsen, IMM.......Professor Mike J. D. Powell spent three weeks at IMM in November - December 2004. During the visit he gave five lectures on radial basis functions. These notes are a TeXified version of his hand-outs, made by Hans Bruun Nielsen, IMM....

  16. Glass Formation of n-Butanol: Coarse-grained Molecular Dynamics Simulations Using Gay-Berne Potential Model

    Institute of Scientific and Technical Information of China (English)

    Gui-long Xie; Yong-hong Zhang; Shi-ping Huang

    2012-01-01

    Using coarse-grained molecular dynamics simulations based on Gay-Berne potential model,we have simulated the cooling process of liquid n-butanol.A new set of GB parameters are obtained by fitting the results of density functional theory calculations.The simulations are carried out in the range of 290-50 K with temperature decrements of 10 K.The cooling characteristics are determined on the basis of the variations of the density,the potential energy and orientational order parameter with temperature,whose slopes all show discontinuity.Both the radial distribution function curves and the second-rank orientational correlation function curves exhibit splitting in the second peak.Using the discontinuous change of these thermodynamic and structure properties,we obtain the glass transition at an estimate of temperature Tg=120±10 K,which is in good agreement with experimental results 110±1 K.

  17. STOCHASTIC COOLING FOR BUNCHED BEAMS.

    Energy Technology Data Exchange (ETDEWEB)

    BLASKIEWICZ, M.

    2005-05-16

    Problems associated with bunched beam stochastic cooling are reviewed. A longitudinal stochastic cooling system for RHIC is under construction and has been partially commissioned. The state of the system and future plans are discussed.

  18. ALP hints from cooling anomalies

    CERN Document Server

    Giannotti, Maurizio

    2015-01-01

    We review the current status of the anomalies in stellar cooling and argue that, among the new physics candidates, an axion-like particle would represent the best option to account for the hinted additional cooling.

  19. Cooling devices in laser therapy

    Directory of Open Access Journals (Sweden)

    Anupam Das

    2016-01-01

    Full Text Available Cooling devices and methods are now integrated into most laser systems, with a view to protecting the epidermis, reducing pain and erythema and improving the efficacy of laser. On the basis of method employed, it can be divided into contact cooling and non-contact cooling. With respect to timing of irradiation of laser, the nomenclatures include pre-cooling, parallel cooling and post-cooling. The choice of the cooling device is dictated by the laser device, the physician′s personal choice with respect to user-friendliness, comfort of the patient, the price and maintenance costs of the device. We hereby briefly review the various techniques of cooling, employed in laser practice.

  20. Electron Cooling Performance at IMP Facility

    CERN Document Server

    Xiaodong, Yang

    2011-01-01

    The ion beam of 58Ni19+ with the energy of 6.39MeV/u was accumulated in the main ring of HIRFL-CSR with the help of electron cooling. The related angle between ion and electron beams in the horizontal and vertical planes was intentionally created by the steering coils in the cooling section after maximized the accumulated ion beam in the ring. The radial electron intensity distribution was changed by the ratio of potentials of grid electrode and anode of the electron gun, the different electron beam profiles were formed from solid to hollow in the experiments. In these conditions, the maximum accumulated ion beam intensity in the 10 seconds was measured, the lifetime of ion beam was measured, simultaneously the momentum spread of the ion beam varying with particle number was measured during the ion beam decay, furthermore, and the power coefficient was derived from these data. In additional, the momentum spread in the case of constant particle number was plotted with the angle and electron beam profile. The o...

  1. Self pumping magnetic cooling

    Science.gov (United States)

    Chaudhary, V.; Wang, Z.; Ray, A.; Sridhar, I.; Ramanujan, R. V.

    2017-01-01

    Efficient thermal management and heat recovery devices are of high technological significance for innovative energy conservation solutions. We describe a study of a self-pumping magnetic cooling device, which does not require external energy input, employing Mn-Zn ferrite nanoparticles suspended in water. The device performance depends strongly on magnetic field strength, nanoparticle content in the fluid and heat load temperature. Cooling (ΔT) by ~20 °C and ~28 °C was achieved by the application of 0.3 T magnetic field when the initial temperature of the heat load was 64 °C and 87 °C, respectively. These experiments results were in good agreement with simulations performed with COMSOL Multiphysics. Our system is a self-regulating device; as the heat load increases, the magnetization of the ferrofluid decreases; leading to an increase in the fluid velocity and consequently, faster heat transfer from the heat source to the heat sink.

  2. Water Cooled Mirror Design

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Holloway, Michael Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pulliam, Elias Noel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-30

    This design is intended to replace the current mirror setup being used for the NorthStar Moly 99 project in order to monitor the target coupon. The existing setup has limited movement for camera alignment and is difficult to align properly. This proposed conceptual design for a water cooled mirror will allow for greater thermal transfer between the mirror and the water block. It will also improve positioning of the mirror by using flexible vacuum hosing and a ball head joint capable of a wide range of motion. Incorporating this design into the target monitoring system will provide more efficient cooling of the mirror which will improve the amount of diffraction caused by the heating of the mirror. The process of aligning the mirror for accurate position will be greatly improved by increasing the range of motion by offering six degrees of freedom.

  3. Magnetic entropy and cooling

    DEFF Research Database (Denmark)

    Hansen, Britt Rosendahl; Kuhn, Luise Theil; Bahl, Christian Robert Haffenden

    2010-01-01

    Some manifestations of magnetism are well-known and utilized on an everyday basis, e.g. using a refrigerator magnet for hanging that important note on the refrigerator door. Others are, so far, more exotic, such as cooling by making use of the magnetocaloric eect. This eect can cause a change...... or nitrogen liquefaction or for room-temperature cooling. The magnetocaloric eect can further be used to determine phase transition boundaries, if a change in the magnetic state occurs at the boundary.In this talk, I will introduce the magnetocaloric eect (MCE) and the two equations, which characterize...... in the temperature of a magnetic material when a magnetic eld is applied or removed. For many years, experimentalists have made use of dilute paramagnetic materials to achieve milliKelvin temperatures by use of the magnetocaloric eect. Also, research is done on materials, which might be used for hydrogen, helium...

  4. Cooling Floor AC Systems

    Science.gov (United States)

    Jun, Lu; Hao, Ding; Hong, Zhang; Ce, Gao Dian

    The present HVAC equipments for the residential buildings in the Hot-summer-and-Cold-winter climate region are still at a high energy consuming level. So that the high efficiency HVAC system is an urgently need for achieving the preset government energy saving goal. With its advantage of highly sanitary, highly comfortable and uniform of temperature field, the hot-water resource floor radiation heating system has been widely accepted. This paper has put forward a new way in air-conditioning, which combines the fresh-air supply unit and such floor radiation system for the dehumidification and cooling in summer or heating in winter. By analyze its advantages and limitations, we found that this so called Cooling/ Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. We also recommend a methodology for the HVAC system designing, which will ensure the reduction of energy cost of users.

  5. Heating, ventilation and cooling

    CSIR Research Space (South Africa)

    Osburn, L

    2009-02-01

    Full Text Available content and is evaporated by the air stream with less moisture. Enthalpy wheels are more effective at transferring energy between the air streams as both sensible and latent heat is transferred. Ground-Coupled Heat Exchanger Ground-coupled heat... with high diurnal temperature variations. Evaporative Coolers Evaporative coolers work on the concept that the evaporation of water has a cooling effect on its immediate environment due to the latent heat that it absorbs in order to evaporate...

  6. Cooled Ion Frequency Standard.

    Science.gov (United States)

    2014-09-26

    when the cooling laser is turned off, the ions are heated by: (1) background gas collisions and (2) a plasma heating process which may be " resonant ...causes heating in our Penning traps. One way resonant particle transport is mediated is by misalignm.nt between the trap’s magnetic and electric axis...using computer solutions. The trap of Fig. 1 is noteworthy because although the inner surfaces of the trap are machined with simple conical cuts, the

  7. Proposal for Laser Cooling of Complex Polyatomic Molecules.

    Science.gov (United States)

    Kozyryev, Ivan; Baum, Louis; Matsuda, Kyle; Doyle, John M

    2016-11-18

    An experimentally feasible strategy for direct laser cooling of polyatomic molecules with six or more atoms is presented. Our approach relies on the attachment of a metal atom to a complex molecule, where it acts as an active photon cycling site. We describe a laser cooling scheme for alkaline earth monoalkoxide free radicals taking advantage of the phase space compression of a cryogenic buffer-gas beam. Possible applications are presented including laser cooling of chiral molecules and slowing of molecular beams using coherent photon processes. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Evolution of the Radial Abundance Gradient and Cold Gas of the Galactic Disk

    Science.gov (United States)

    Qi-Shi, Chen; Rui-Xiang, Chang; Jun, Yin

    2014-10-01

    In order to understand the forming mechanism of the radial abun- dance gradient of the Galactic disk and the evolution of cold gas, we have con- structed a chemical evolution model of the Galactic disk, in which the star for- mation law concerned with molecular hydrogens is adopted, and the evolution of mass surface density is calculated for the molecular and atomic hydrogens separately, then the model predictions and the observed radial distributions of some physical quantities are compared. The result indicates that the model prediction is sensitive to the adopted infall timescale, the model which adopts the star formation law concerned with the molecular hydrogens can agree well with the major observed properties of the Galactic disk, especially can obtain naturally the radial oxygen abundance gradient of the Galactic disk, and the radial surface density profile of cold gas. The assumption of instantaneous or non-instantaneous recycling approximation has a small effect on the evolution of cold gas, especially in the case of rather low gas density.

  9. Electron Cooling of RHIC

    CERN Document Server

    Ben-Zvi, Ilan; Barton, Donald; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Bruhwiler, David L; Burger, Al; Burov, Alexey; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Derbenev, Yaroslav S; Eidelman, Yury I; Favale, Anthony; Fedotov, Alexei V; Fischer, Wolfram; Funk, L W; Gassner, David M; Hahn, Harald; Harrison, Michael; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Koop, Ivan; Lambiase, Robert; Litvinenko, Vladimir N; MacKay, William W; Mahler, George; Malitsky, Nikolay; McIntyre, Gary; Meng, Wuzheng; Merminga, Lia; Meshkov, Igor; Mirabella, Kerry; Montag, Christoph; Nagaitsev, Sergei; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Parkhomchuk, Vasily; Parzen, George; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Sekutowicz, Jacek; Shatunov, Yuri; Sidorin, Anatoly O; Skrinsky, Aleksander Nikolayevich; Smirnov, Alexander V; Smith, Kevin T; Todd, Alan M M; Trbojevic, Dejan; Troubnikov, Grigory; Wang, Gang; Wei, Jie; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Zaltsman, Alex; Zhao, Yongxiang; ain, Animesh K

    2005-01-01

    We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...

  10. Low mass integrated cooling

    CERN Document Server

    Mapelli, Alessandro

    2014-01-01

    Low mass on - detec tor cooling systems are being developed and stud ied by the Detector Technology group (PH - DT) in the CERN Physics Department in close collaboration with LHC and non - LHC experiments . Two approaches are currently being investigated. The first approach, for barrel configurations, consists in integrating the cooli ng apparatus in light mechanical structures support ing the detectors. In this case , the thermal management can be achieved either with light cooling pipes and thin plates or with a network of microchannels embedded in thin strips of silicon or polyimide . Both configuratio ns are being investigated in the context of the 2018 upgrade program of the ALICE Inner Tracking System (ITS). Moreover, it is also possible to use a s ilicon microchannel cooling device itself as structural support for the detectors and electronics. Such a configur ation has been adopted by the NA62 collaboration for the ir GigaTracKer (GTK) as well as by the LHCb collaboration for the 2018 major upgrade of...

  11. Simulation of Desiccant Cooling

    Directory of Open Access Journals (Sweden)

    Kamaruddin A.

    2017-06-01

    Full Text Available Desiccant cooling system has been an attractive topic for study lately, due to its environmentally friendly nature. It also consume less electricity and capable to be operated without refrigerant. A simulation study was conducted using 1.5 m long ducting equipped with one desiccant wheel, one sensible heat exchanger wheel, one evaporative cooling chamber and two blowers and one electric heater. The simulation study used 8.16 m/s primary air, the drying coefficient from desiccant wheel, k1=2.1 (1/s, mass transfer coefficient in evaporative cooling, k2=1.2 kg vapor/s, heat transfer coefficient in desiccant wheel, h1=4.5 W/m2 oC, and heat transfer coefficient in sensible heat exchanger wheel h2= 4.5 W/m2 oC. The simulation results show that the final temperature before entering into the air conditioning room was 25 oC and RH of 65 %, were in accordance with the Indonesian comfort index.

  12. Design, fabrication and measurement of a novel cooling arm for fusion energy source

    CERN Document Server

    Jiang, Shui-Dong; Mei, Jia-Bin; Yang, Bin; Yang, Chun-Sheng

    2012-01-01

    The issues of energy and environment are the main constraint of sustainable development in worldwide. Nuclear energy source is one important optional choice for long term sustainable development. The nuclear energy consists of fusion energy and fission energy. Compared with fission, inertial confinement fusion (ICF) is a kind of clean fusion energy and can generate large energy and little environmental pollution. ICF mainly consists of peripheral driver unit and target. The cooling arm is an important component of the target, which cools the hohlraum to maintain the required temperature and positions the thermal-mechanical package (TMP) assembly. This paper mainly investigates the cooling arm, including the structural design, the verticality of sidewall and the mechanical properties. The TMP assembly is uniformly clamped in its radial when using (111) crystal orientation silicon to fabricate cooling arm. The finite element method is used to design the structure of cooling arm with 16 clamping arms, and the ME...

  13. One-year results of cemented bipolar radial head prostheses for comminuted radial head fractures

    Directory of Open Access Journals (Sweden)

    Laun, Reinhold

    2015-12-01

    Full Text Available Introduction: Comminuted radial head fractures (Mason type III continue to pose a challenge to orthopedic surgeons. When internal fixation is not possible, radial head arthroplasty has been advocated as the treatment of choice. The purpose of this retrospective study was to evaluate clinical and radiological short-term results of patients with Mason type III radial head fractures treated with a cemented bipolar radial prosthesis. Methods: Twelve patients received cemented bipolar radial head hemiarthroplasty for comminuted radial head fractures. In all patients a CT scan was obtained prior to surgical treatment to assess all associated injuries. Postoperatively an early motion protocol was applied. All patients were evaluated clinically and radiologically at an average of 12.7 months.Results: According to the Mayo Modified Wrist Score, the Mayo Elbow Performance Score, the functional rating index of Broberg and Morrey, and the DASH Score good to excellent results were obtained. Grip strength and range of motion were almost at the level of the unaffected contralateral side. Patient satisfaction was high, no instability or signs of loosening of the implant, and only mild signs of osteoarthritis were seen.Conclusion: Overall good to excellent short-term results for primary arthroplasty for comminuted radial head fractures were observed. These encouraging results warrant the conduction of further studies with long-term follow-up and more cases to see if these short-term results can be maintained over time.

  14. The Early Outcomes with Titanium Radial Head Implants in the Treatment of Radial Head Comminuted Fractures

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jijun; YANG Shuhua; HU Yong

    2007-01-01

    The study assessed the early functional outcomes with cemented titanium implants of ra- dius in the treatment of comminuted fractures of radial heads. The functional outcomes of arthro- plasty with cemented titanium implants of radius in the treatment of radial head fractures (Mason Type Ⅲ: 6; Mason Type Ⅳ: 4) in l0 consecutive patients (mean age, 38 years) were evaluated over a mean time of 23.7 months (18-31 months). The patients were assessed on the basis of physical ex- amination, functional rating (Mayo) and radiographic findings. The parameters evaluated included motion, stability, pain, and grip strength. Five patients were considered to have excellent results, 4 patients had good results and 1 patient had fairly good results. There were no cases of infection, prosthetic failure, heterotopic ossification or dislocation. When medial collateral ligament was injured, radial head became the main stabilizing structure of the elbow. Titanium radial head implant may provide the stability similar to that of native radial head. We believe that titanium radial head im- plants may be indicated for the Mason Type Ⅲ and Mason Type Ⅳ radial head fractures.

  15. Ultraefficient Cooling of Resonators: Beating Sideband Cooling with Quantum Control

    Science.gov (United States)

    Wang, Xiaoting; Vinjanampathy, Sai; Strauch, Frederick; Jacobs, Kurt

    2012-02-01

    There is presently a great deal of interest in cooling high-frequency micro- and nano-mechanical oscillators to their ground states. The present state of the art in cooling mechanical resonators is a version of sideband cooling, which was originally developed in the context of cooling trapped ions. Here we present a method based on quantum control that uses the same configuration as sideband cooling--coupling the resonator to be cooled to a second microwave (or optical) auxiliary resonator--but will cool significantly colder. This is achieved by applying optimal control and varying the strength of the coupling between the two resonators over a time on the order of the period of the mechanical resonator. As part of our analysis, we also obtain a method for fast, high-fidelity quantum information transfer between resonators.

  16. A 1D (radial) Plasma Jet Propagation Study for the Plasma Liner Experiment (PLX)

    Science.gov (United States)

    Thompson, J. R.; Bogatu, I. N.; Galkin, S. A.; Kim, J. S.; Welch, D. R.; Thoma, C.; Golovkin, I.; Macfarlane, J. J.; Case, A.; Messer, S. J.; Witherspoon, F. D.; Cassibry, J. T.; Awe, T. J.; Hsu, S. C.

    2011-10-01

    The Plasma Liner Experiment will explore the formation of imploding spherical ``plasma liners'' that reach peak pressures of 0.1 Mbar upon stagnation. The liners will be formed through the merging of dense, high velocity plasma jets (n ~1017 cm-3, T ~3 eV, v ~50 km/s) in a spherically convergent geometry. The focus of this 1D (radial) study is argon plasma jet evolution during propagation from the rail gun source to the jet merging radius. The study utilizes the Large Scale Plasma (LSP) PIC code with atomic physics included through the use of a non-Local Thermal Equilibrium (NLTE) Equation of State (EOS) table. We will present scenarios for expected 1D (radial) plasma jet evolution, from upon exiting the PLX rail gun to reaching the jet merging radius. The importance of radiation cooling early in the simulation is highlighted. Work supported by US DOE grant DE-FG02-05ER54835.

  17. RBF networks with mixed radial basis functions

    NARCIS (Netherlands)

    Ciftcioglu, O.; Sariyildiz, I.S.

    2000-01-01

    After the introduction to neural network technology as multivariable function approximation, radial basis function (RBF) networks have been studied in many different aspects in recent years. From the theoretical viewpoint, approximation and uniqueness of the interpolation is studied and it has been

  18. Determining Enzyme Activity by Radial Diffusion

    Science.gov (United States)

    Davis, Bill D.

    1977-01-01

    Discusses advantages of radial diffusion assay in determining presence of enzyme and/or rough approximation of amount of enzyme activities. Procedures are included for the preparation of starch-agar plates, and the application and determination of enzyme. Techniques using plant materials (homogenates, tissues, ungerminated embryos, and seedlings)…

  19. Dual-radial cell thermionic fuel element

    Science.gov (United States)

    Terrell, Charles W.

    A dual-radial cell thermionic fuel element (TFE) has been proposed and partially evaluated. The cell has the capacity to produce considerably more power per gram of fuel than does a single-cell TFE, with a total electrical power in a fast reactor system of several hundred kWs, conservatively operated.

  20. Explaining Adaptive Radial-Based Direction Sampling

    NARCIS (Netherlands)

    L. Bauwens (Luc); C.S. Bos (Charles); H.K. van Dijk (Herman); R.D. van Oest (Rutger)

    2003-01-01

    textabstractIn this short paper we summarize the computational steps of Adaptive Radial-Based Direction Sampling (ARDS), which can be used for Bayesian analysis of ill behaved target densities. We consider one simulation experiment in order to illustrate the good performance of ARDS relative to the

  1. Determining Enzyme Activity by Radial Diffusion

    Science.gov (United States)

    Davis, Bill D.

    1977-01-01

    Discusses advantages of radial diffusion assay in determining presence of enzyme and/or rough approximation of amount of enzyme activities. Procedures are included for the preparation of starch-agar plates, and the application and determination of enzyme. Techniques using plant materials (homogenates, tissues, ungerminated embryos, and seedlings)…

  2. Radial Distance Estimation with Tapered Whisker Sensors.

    Science.gov (United States)

    Ahn, Sejoon; Kim, DaeEun

    2017-07-19

    Rats use their whiskers as tactile sensors to sense their environment. Active whisking, moving whiskers back and forth continuously, is one of prominent features observed in rodents. They can discriminate different textures or extract features of a nearby object such as size, shape and distance through active whisking. There have been studies to localize objects with artificial whiskers inspired by rat whiskers. The linear whisker model based on beam theory has been used to estimate the radial distance, that is, the distance between the base of the whisker and a target object. In this paper, we investigate deflection angle measurements instead of forces or moments, based on a linear tapered whisker model to see the role of tapered whiskers found in real animals. We analyze how accurately this model estimates the radial distance, and quantify the estimation errors and noise sensitivity. We also compare the linear model simulation and nonlinear numerical solutions. It is shown that the radial distance can be estimated using deflection angles at two different positions on the tapered whisker. We argue that the tapered whisker has an advantage of estimating the radial distance better, as compared to an untapered whisker, and active sensing allows that estimation without the whisker's material property and thickness or the moment at base. In addition, we investigate the potential of passive sensing for tactile localization.

  3. Radial interchange motions of plasma filaments

    DEFF Research Database (Denmark)

    Garcia, O.E.; Bian, N.H.; Fundamenski, W.

    2006-01-01

    reduces the radial velocity of isolated filaments. The results are discussed in the context of convective transport in scrape-off layer plasmas, comprising both blob-like structures in low confinement modes and edge localized mode filaments in unstable high confinement regimes. (c) 2006 American Institute...

  4. Radial-Gap Motor for Ship Propulsion

    Science.gov (United States)

    Yanamoto, Toshiyuki; Yokoyama, Minoru

    The KHI team has developed radial gap high-temperature superconducting (HTS) motors of three sizes, 1 MW-class, 3 MW, and 20 MW, to be used for electric propulsion systems for ships. The volumetric torque density of the assembled 3 MW HTS motor was recorded at 40 kNm/m3 in the load test; the world's highest in the class.

  5. On the Formation of Molecular Clumps in QSO Outflows

    Science.gov (United States)

    Ferrara, A.; Scannapieco, E.

    2016-12-01

    We study the origin of the cold molecular clumps in quasar outflows, recently detected in CO and HCN emission. We first describe the physical properties of such radiation-driven outflows and show that a transition from a momentum- to an energy-driven flow must occur at a radial distance of R≈ 0.25 {kpc}. During this transition, the shell of swept-up material fragments due to Rayleigh-Taylor instabilities, but these clumps contain little mass and are likely to be rapidly ablated by the hot gas in which they are immersed. We then explore an alternative scenario in which clumps form from thermal instabilities at R≳ 1 {kpc}, possibly containing enough dust to catalyze molecule formation. We investigate this process with 3D two-fluid (gas+dust) numerical simulations of a kpc3 patch of the outflow, including atomic and dust cooling, thermal conduction, dust sputtering, and photoionization from the QSO radiation field. In all cases, dust grains are rapidly destroyed in ≈ {10}4 years; and while some cold clumps form at later times, they are present only as transient features, which disappear as cooling becomes more widespread. In fact, we only find a stable two-phase medium with dense clumps if we artificially enhance the QSO radiation field by a factor of 100. This result, together with the complete destruction of dust grains, renders the interpretation of molecular outflows a very challenging problem.

  6. Cooling lubricants; Kuehlschmierstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiffer, W. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Breuer, D. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Blome, H. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Deininger, C. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Hahn, J.U. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Kleine, H. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Nies, E. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Pflaumbaum, W. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Stockmann, R. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Willert, G. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Sonnenschein, G. [Maschinenbau- und Metall-Berufsgenossenschaft, Duesseldorf (Germany)

    1996-08-01

    As a rule, the base substances used are certain liquid hydrocarbons from mineral oils as well as from native and synthetic oils. Through the addition of further substances the cooling lubricant takes on the particular qualities required for the use in question. Employees working with cooling lubricants are exposed to various hazards. The assessment of the concentrations at the work station is carried out on the basis of existing technical rules for contact with hazardous substances. However, the application/implementation of compulsory investigation and supervision in accordance with these rules is made difficult by the fact that cooling lubricants are, as a rule, made up of complicated compound mixtures. In addition to protecting employees from exposure to mists and vapours from the cooling lubricants, protection for the skin is also of particular importance. Cooling lubricants should not, if at all possible, be brought into contact with the skin. Cleansing the skin and skin care is just as important as changing working clothes regularly, and hygiene and cleanliness at the workplace. Unavoidable emissions are to be immediately collected at the point where they arise or are released and safely disposed of. This means taking into account all sources of emissions. The programme presented in this report therefore gives a very detailed account of the individual protective measures and provides recommendations for the design of technical protection facilities. (orig./MG) [Deutsch] Als Basisstoffe dienen in der Regel bestimmte fluessige Kohlenwasserstoffverbindungen aus Mineraloelen sowie aus nativen oder synthetischen Oelen. Durch die Zugabe von weiteren Stoffen erlangt der Kuehlschmierstoff seine fuer den jeweiligen Anwendungsabfall geforderten Eigenschaften. Beschaeftigte, die mit Kuehlschmierstoffen umgehen, sind unterschiedliche Gefahren ausgesetzt. Die Beurteilung der Kuehlschmierstoffkonzentrationen in der Luft am Arbeitsplatz erfolgt auf der Grundlage bestehender

  7. Numerical investigation of the influence of cooling flux on the generation of dislocations in cylindrical mono-like silicon growth

    Science.gov (United States)

    Gao, B.; Kakimoto, K.

    2013-12-01

    To effectively reduce dislocations during seeded growth of cylindrical monocrystalline-like silicon by controlling the cooling flux, the relationship between the generation of dislocations and cooling flux has been numerically studied. The results show that the generation of dislocations is determined by the cooling flux difference, not by the cooling flux inside the crystal. Good control of the input and output cooling fluxes during practical crystal growth is essential to reduce the generation of dislocations. Further analysis shows that the cooling flux difference in the radial or axial direction is linearly related to the square root of the maximum dislocation density. In other words, a linear decrease of the cooling flux difference in the radial or axial direction results in a quadratic decrease of the maximum dislocation density. Therefore, the most effective method to reduce dislocations during the cooling process is to decrease the cooling flux difference between the input and output fluxes, i.e., to decrease the energy accumulation or dissipation rate inside the whole crystal.

  8. Molecular fountain.

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Kevin E.; Chandler, David W.

    2009-09-01

    A molecular fountain directs slowly moving molecules against gravity to further slow them to translational energies that they can be trapped and studied. If the molecules are initially slow enough they will return some time later to the position from which they were launched. Because this round trip time can be on the order of a second a single molecule can be observed for times sufficient to perform Hz level spectroscopy. The goal of this LDRD proposal was to construct a novel Molecular Fountain apparatus capable of producing dilute samples of molecules at near zero temperatures in well-defined user-selectable, quantum states. The slowly moving molecules used in this research are produced by the previously developed Kinematic Cooling technique, which uses a crossed atomic and molecular beam apparatus to generate single rotational level molecular samples moving slowly in the laboratory reference frame. The Kinematic Cooling technique produces cold molecules from a supersonic molecular beam via single collisions with a supersonic atomic beam. A single collision of an atom with a molecule occurring at the correct energy and relative velocity can cause a small fraction of the molecules to move very slowly vertically against gravity in the laboratory. These slowly moving molecules are captured by an electrostatic hexapole guiding field that both orients and focuses the molecules. The molecules are focused into the ionization region of a time-of-flight mass spectrometer and are ionized by laser radiation. The new molecular fountain apparatus was built utilizing a new design for molecular beam apparatus that has allowed us to miniaturize the apparatus. This new design minimizes the volumes and surface area of the machine allowing smaller pumps to maintain the necessary background pressures needed for these experiments.

  9. Radial wave crystals: radially periodic structures from anisotropic metamaterials for engineering acoustic or electromagnetic waves.

    Science.gov (United States)

    Torrent, Daniel; Sánchez-Dehesa, José

    2009-08-07

    We demonstrate that metamaterials with anisotropic properties can be used to develop a new class of periodic structures that has been named radial wave crystals. They can be sonic or photonic, and wave propagation along the radial directions is obtained through Bloch states like in usual sonic or photonic crystals. The band structure of the proposed structures can be tailored in a large amount to get exciting novel wave phenomena. For example, it is shown that acoustical cavities based on radial sonic crystals can be employed as passive devices for beam forming or dynamically orientated antennas for sound localization.

  10. Variations in the usage and composition of a radial cocktail during radial access coronary angiography procedures.

    LENUS (Irish Health Repository)

    Pate, G

    2011-10-01

    A survey was conducted of medication administered during radial artery cannulation for coronary angiography in 2009 in Ireland; responses were obtained for 15 of 20 centres, in 5 of which no radial access procedures were undertaken. All 10 (100%) centres which provided data used heparin and one or more anti-spasmodics; verapamil in 9 (90%), nitrate in 1 (10%), both in 2 (20%). There were significant variations in the doses used. Further work needs to be done to determine the optimum cocktail to prevent radial artery injury following coronary angiography.

  11. Radial Heat Transfer Dynamics in Multiwall Carbon Nanotubes

    Science.gov (United States)

    Osman, Mohamed; Kim, Taejin

    2006-05-01

    The dynamics of radial heat transfer in zigzag and armchair double wall carbon nanotubes (DWCNT) have been examined using molecular dynamic (MD) simulations with the goal of understanding the role of radial phonon modes in heat transfer. The MD model uses Tersof-Brenner potential for bonded C-C interactions within each shell and non-bended van der Wall interaction between inner and outer shells. The simulation procedure involves, (1) quenching the DWNT to 0 K, (2) minimization of the potential energy and (3) raising the temperature of the outer shell to the desired steady state temperature while maintaining the inner tube at 0.1 K. The heat baths are removed from the outer and inner shell and their energies are examined. The energies of inner and outer exhibit an out of phase oscillatory behavior due the exchange of the energies between the two shells. The energy of the inner tube shows a weak gradual increase due to the temperature gradient. The beat frequencies determined from the Fourier transform of the energy oscillations of the inner and outer nanotubes were found to be in the tera Herz range. We will also discuss the temperature and length dependence of oscillatory energy exchange between the nanotube shells.

  12. The radial distribution of supernovae in nuclear starbursts

    Science.gov (United States)

    Herrero-Illana, R.; Pérez-Torres, M. A.; Alberdi, A.

    2013-05-01

    Galaxy-galaxy interactions are expected to be responsible for triggering massive star formation and possibly accretion onto a supermassive black hole, by providing large amounts of dense molecular gas down to the central kiloparsec region. Several scenarios to drive the gas further down to the central ˜100 pc, have been proposed, including the formation of a nuclear disk around the black hole, where massive stars would produce supernovae. Here, we probe the radial distribution of supernovae and supernova remnants in the nuclear regions of the starburst galaxies M82, Arp 299-A, and Arp 220, by using high-angular resolution (≲ 0.''1) radio observations. We derived scale-length values for the putative nuclear disks, which range from ˜20-30 pc for Arp 299-A and Arp 220, up to ˜140 pc for M82. The radial distribution of SNe for the nuclear disks in Arp 299-A and Arp 220 is also consistent with a power-law surface density profile of exponent γ = 1, as expected from detailed hydrodynamical simulations of nuclear disks. This study is detailed in te{herrero-illana12}.

  13. Radial keratotomy enhancements for residual myopia.

    Science.gov (United States)

    Gayton, J L; Van der Karr, M; Sanders, V

    1997-01-01

    A systematic method of performing radial keratotomy enhancements in undercorrected eyes may increase accuracy and predictability and decrease the number of procedures required. A consecutive series of 372 radial keratotomy procedures, including 110 eyes that received enhancements under a systematic protocol, was evaluated. Radial keratotomy was performed using the Reliable Keratotomy software, which uses the Thornton nomogram for primary radial keratotomy and provides a systematic method of performing enhancements. Ninety eyes (24%) received one enhancement, 16 eyes (4%) received two enhancements, and four eyes (1%) received three enhancements. Mean final spherical equivalent refraction was -0.44 D (-4.00 to +1.875 D, SD 0.86) for eyes that did not receive enhancements and -0.44 D (-2.50 to +1.00 D, SD 0.61) for eyes that had enhancements. Mean final residual myopia for the entire cohort was -0.44 D (-4.00 to +1.875 D, SD 0.79). At final examination, 242 (65%) eyes had a refraction within +/- 0.5 D and 298 (80%) within +/- 1.00. Among eyes that received enhancements, 75 (68%) had a refraction within +/- 0.50 D, and 89 (81%) within +/- 1.00 D; 40 eyes (36%) had uncorrected visual acuity of 20/20 or better, 99 eyes (90%) 20/40 or better, and all but one eye (99%) 20/80 or better at the final postoperative examination. Among the entire cohort, 130 eyes (35%) had uncorrected visual acuity of 20/20 or better, 312 (84%) had 20/40 or better, and 350 (94%) had 20/80 or better. No eye lost more than one line of spectacle-corrected visual acuity. A systematic approach to enhancement of undercorrected eyes after radial keratotomy, combined with accurate surgery, may reduce the need for multiple enhancements as well as the overcorrection rate, and provide improved uncorrected visual acuity.

  14. Mechanical properties and electronic structures of one BN nanotube under radial compression

    Institute of Scientific and Technical Information of China (English)

    Hai-jun SHEN

    2009-01-01

    The Tersoff-potential based MD (molecular dynamics)method was used to simulate the radial compression of one(10,0)BN nanotube,and its compressive pmpertes was compared with those of one (10,0)carbon nanotube The semi-empirical PM3 QC (Quantum chemistry)method was adopted to calculate the electronic structures of the compressed BN-tube,and the effect of the radial compression on the electronic structures of the BN-tube was discussed. It is shown that(I) BN-tube has comparable radial compressive stiffness to carbon-tube,but lower energy-absorbing,load-support and deformation-support capabilities,and (ii) with the increase of compressive strain,the HOMO energy of the BN-tube lncreases the LUMO energy and the LUMO-HOMOenergy-gap decrease,and its chemical activity and conductance increase.

  15. Change of Radial Gap Value in Axial Compressors at Modes of Turbine Plant Heating and Shut-Down

    Directory of Open Access Journals (Sweden)

    A. S. Laskine

    2007-01-01

    Full Text Available Designing of highly-efficient axial compressors is connected with their better aerodynamic cleanness. One of the ways is to minimize radial clearances for decreasing leakages and, consequently, increasing efficiency. At the same time it is necessary to exclude stator touching by rotor blades.ANSYS complex has been used to reduce a gap by 1.5–2.0-fold in comparison with the existing one.It has become possible to obtain dependences of radial displacement of peripheral blade edge and stator ring element, located above it, on heating time.Practical and research value of the paper is in the development of a methodology for calculation of heating (cooling, which can be applied while designing axial turbine machines and evaluating the possible minimization of radial gap in the case that excludes touching.

  16. Process integration: Cooling water systems design

    CSIR Research Space (South Africa)

    Gololo, KV

    2010-10-01

    Full Text Available This paper presents a technique for grassroot design of cooling water system for wastewater minimization which incorporates the performances of the cooling towers involved. The study focuses mainly on cooling systems consisting of multiple cooling...

  17. Cooling water systems design using process integration

    CSIR Research Space (South Africa)

    Gololo, KV

    2010-09-01

    Full Text Available Cooling water systems are generally designed with a set of heat exchangers arranged in parallel. This arrangement results in higher cooling water flowrate and low cooling water return temperature thus reducing cooling tower efficiency. Previous...

  18. A new radial system of dark globules in Monoceros

    CERN Document Server

    Carrasco-Gonz'alez, C; Gyulbudaghian, A; Anglada, G; Lee, C W

    2005-01-01

    Aims. We analyze the LBN 978 HII region in order to study the HII/molecular cloud interaction. Methods. We used the IAC-80 telescope to image the region with narrow-band filters and the Very Large Array to obtain a radio continuum map at 3.6 cm. We also used the DSS2 red images and the NRAO VLA Sky Survey at 20 cm. Results. We have discovered a new radial system of dark globules associated with the LBN 978 HII region, containing a group of at least eight cometary bright-rimmed globules with the same morphological type. The brightest source is also detected in the radio continuum. Analysis of optical and radio emission suggest that this object is photoionized by HD 47432, the central star of the LBN 978 HII region.

  19. Radial velocities of population II binary stars. II

    CERN Document Server

    Bartkevicius, A

    2006-01-01

    Here we publish the second list of radial velocities for 91 Hipparcos stars, mostly high transverse velocity binaries without previous radial velocity measurements. The measurements of radial velocities are done with a CORAVEL-type radial velocity spectrometer with an accuracy better than 1 km/s. We also present the information on eight new radial velocity variables - HD 29696, HD 117466AB, BD +28 4035AB, BD +30 2129A, BD +39 1828AB, BD +69 230A, BD +82 565A and TYC 2267-1300-1 - found from our measurements. Two stars (HD 27961AB and HD 75632AB) are suspected as possible radial velocity variables.

  20. Laser-cooled continuous ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Schiffer, J.P.; Hangst, J.S.; Nielsen, J.S. [and others

    1995-08-01

    A collaboration with a group in Arhus, Denmark, using their storage ring ASTRID, brought about better understanding of ion beams cooled to very low temperatures. The longitudinal Schottky fluctuation noise signals from a cooled beam were studied. The fluctuation signals are distorted by the effects of space charge as was observed in earlier measurements at other facilities. However, the signal also exhibits previously unobserved coherent components. The ions` velocity distribution, measured by a laser fluorescence technique suggests that the coherence is due to suppression of Landau damping. The observed behavior has important implications for the eventual attainment of a crystalline ion beam in a storage ring. A significant issue is the transverse temperature of the beam -- where no direct diagnostics are available and where molecular dynamics simulations raise interesting questions about equilibrium.

  1. Laser-cooling-assisted mass spectrometry

    CERN Document Server

    Schneider, Christian; Chen, Kuang; Sullivan, Scott T; Hudson, Eric R

    2014-01-01

    Mass spectrometry is used in a wide range of scientific disciplines including proteomics, pharmaceutics, forensics, and fundamental physics and chemistry. Given this ubiquity, there is a worldwide effort to improve the efficiency and resolution of mass spectrometers. However, the performance of all techniques is ultimately limited by the initial phase-space distribution of the molecules being analyzed. Here, we dramatically reduce the width of this initial phase-space distribution by sympathetically cooling the input molecules with laser-cooled, co-trapped atomic ions, improving both the mass resolution and detection efficiency of a time-of-flight mass spectrometer by over an order of magnitude. Detailed molecular dynamics simulations verify the technique and aid with evaluating its effectiveness. Our technique appears to be applicable to other types of mass spectrometers.

  2. Laser-Cooling-Assisted Mass Spectrometry

    Science.gov (United States)

    Schneider, Christian; Schowalter, Steven J.; Chen, Kuang; Sullivan, Scott T.; Hudson, Eric R.

    2014-09-01

    Mass spectrometry is used in a wide range of scientific disciplines including proteomics, pharmaceutics, forensics, and fundamental physics and chemistry. Given this ubiquity, there is a worldwide effort to improve the efficiency and resolution of mass spectrometers. However, the performance of all techniques is ultimately limited by the initial phase-space distribution of the molecules being analyzed. Here, we dramatically reduce the width of this initial phase-space distribution by sympathetically cooling the input molecules with laser-cooled, cotrapped atomic ions, improving both the mass resolution and detection efficiency of a time-of-flight mass spectrometer by over an order of magnitude. Detailed molecular-dynamics simulations verify the technique and aid with evaluating its effectiveness. This technique appears to be applicable to other types of mass spectrometers.

  3. Solar heating and cooling.

    Science.gov (United States)

    Duffie, J A; Beckman, W A

    1976-01-16

    We have adequate theory and engineering capability to design, install, and use equipment for solar space and water heating. Energy can be delivered at costs that are competitive now with such high-cost energy sources as much fuel-generated, electrical resistance heating. The technology of heating is being improved through collector developments, improved materials, and studies of new ways to carry out the heating processes. Solar cooling is still in the experimental stage. Relatively few experiments have yielded information on solar operation of absorption coolers, on use of night sky radiation in locations with clear skies, on the combination of a solar-operated Rankine engine and a compression cooler, and on open cycle, humidification-dehumidification systems. Many more possibilities for exploration exist. Solar cooling may benefit from collector developments that permit energy delivery at higher temperatures and thus solar operation of additional kinds of cycles. Improved solar cooling capability can open up new applications of solar energy, particularly for larger buildings, and can result in markets for retrofitting existing buildings. Solar energy for buildings can, in the next decade, make a significant contribution to the national energy economy and to the pocketbooks of many individual users. very large-aggregate enterprises in manufacture, sale, and installation of solar energy equipment can result, which can involve a spectrum of large and small businesses. In our view, the technology is here or will soon be at hand; thus the basic decisions as to whether the United States uses this resource will be political in nature.

  4. Radiation Dose Reduction during Radial Cardiac Catheterization: Evaluation of a Dedicated Radial Angiography Absorption Shielding Drape

    OpenAIRE

    Andrew Ertel; Jeffrey Nadelson; Adhir R. Shroff; Ranya Sweis; Dean Ferrera; Vidovich, Mladen I.

    2012-01-01

    Objectives. Radiation scatter protection shield drapes have been designed with the goal of decreasing radiation dose to the operators during transfemoral catheterization. We sought to investigate the impact on operator radiation exposure of various shielding drapes specifically designed for the radial approach. Background. Radial access for cardiac catheterization has increased due to improved patient comfort and decreased bleeding complications. There are concerns for increased radiation exp...

  5. Analysis of the JASPER Program Radial Shield Attenuation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Slater, C.O.

    1993-01-01

    The results of the analysis of the JASPER Program Radial Shield Attenuation Experiment are presented. The experiment was performed in 1986 at the ORNL Tower Shielding Facility. It is the first of six experiments in this cooperative Japanese and American program in support of shielding designs for advanced sodium-cooled reactors. Six different shielding configurations and subconfigurations thereof were studied. The configurations were calculated with the DOT-IV two-dimensional discrete ordinates radiation transport computer code using the R-Z geometry option, a symmetric S{sub 12} quadrature (96 directions), and cross sections from ENDF/B versions IV and V in either a 51- or 61-group structure. Auxiliary codes were used to compute detector responses and prepare cross sections and source input for the DOT-IV calculations. Calculated detector responses were compared with measured responses and the agreement was good to excellent in many cases. However, the agreement for configurations having thick steel or B{sub 4}C regions or for some very large configurations was fair to poor. The disagreement was attributed to cross-section data, broad-group structure, or high background in the measurements. In particular, it is shown that two cross-section sets for ``B give very different results for neutron transmission through the thick B{sub 4}C regions used in one set of experimental configurations. Implications for design calculations are given.

  6. Laser Cooling of Solids

    Science.gov (United States)

    2009-01-01

    observed in a range of glasses and crystals doped with Yb3+ (ZBLANP [19–22], ZBLAN [23,24], CNBZn [9,25] BIG [25, 26], KGd(WO4)2 [9], KY(WO4)2 [9], YAG [27...Yb3+-doped fluorozirconate glass ZBLAN , Phys. Rev. B 75, 144302 (2007). [40] C. W. Hoyt, Laser Cooling in Thulium-doped Solids, Ph. D. Thesis...date, optical refrigeration research has been confined to glasses and crystals doped with rare- earth elements and direct-band semiconductors such as

  7. Entropy generation of radial rotation convective channels

    Science.gov (United States)

    Alić, Fikret

    2012-03-01

    The exchange of heat between two fluids is established by radial rotating pipe or a channel. The hotter fluid flows through the pipe, while the cold fluid is ambient air. Total length of pipe is made up of multiple sections of different shape and position in relation to the common axis of rotation. In such heat exchanger the hydraulic and thermal irreversibility of the hotter and colder fluid occur. Therefore, the total entropy generated within the radial rotating pipe consists of the total entropy of hotter and colder fluid, taking into account all the hydraulic and thermal irreversibility of both fluids. Finding a mathematical model of the total generated entropy is based on coupled mathematical expressions that combine hydraulic and thermal effects of both fluids with the complex geometry of the radial rotating pipe. Mathematical model follows the each section of the pipe and establishes the function between the sections, so the total generated entropy is different from section to section of the pipe. In one section of the pipe thermal irreversibility may dominate over the hydraulic irreversibility, while in another section of the pipe the situation may be reverse. In this paper, continuous analytic functions that connect sections of pipe in geometric meaning are associated with functions that describe the thermo-hydraulic effects of hotter and colder fluid. In this way, the total generated entropy of the radial rotating pipe is a continuous analytic function of any complex geometry of the rotating pipe. The above method of establishing a relationship between the continuous function of entropy with the complex geometry of the rotating pipe enables indirect monitoring of unnecessary hydraulic and thermal losses of both fluids. Therefore, continuous analytic functions of generated entropy enable analysis of hydraulic and thermal irreversibility of individual sections of pipe, as well as the possibility of improving the thermal-hydraulic performance of the rotating

  8. Evaporative cooling of antiprotons for the production of trappable antihydrogen

    Science.gov (United States)

    Silveira, D. M.; Andresen, G. B.; Ashkezari, M. D.; Baquero-Ruiz, M.; Bertsche, W.; Bowe, P. D.; Butler, E.; Cesar, C. L.; Chapman, S.; Charlton, M.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Hangst, J. S.; Hardy, W. N.; Hayden, M. E.; Hydomako, R.; Jonsell, S.; Kurchaninov, L.; Madsen, N.; Menary, S.; Nolan, P.; Olchanski, K.; Olin, A.; Povilus, A.; Pusa, P.; Robicheaux, F.; Sarid, E.; So, C.; Storey, J. W.; Thompson, R. I.; van der Werf, D. P.; Wurtele, J. S.

    2013-03-01

    We describe the implementation of evaporative cooling of charged particles in the ALPHA apparatus. Forced evaporation has been applied to cold samples of antiprotons held in Malmberg-Penning traps. Temperatures on the order of 10 K were obtained, while retaining a significant fraction of the initial number of particles. We have developed a model for the evaporation process based on simple rate equations and applied it succesfully to the experimental data. We have also observed radial re-distribution of the clouds following evaporation, explained by simple conservation laws. We discuss the relevance of this technique for the recent demonstration of magnetic trapping of antihydrogen.

  9. Diffusing, side-firing, and radial delivery laser balloon catheters for creating subsurface thermal lesions in tissue

    Science.gov (United States)

    Chang, Chun-Hung; Fried, Nathaniel M.

    2016-02-01

    Infrared lasers have been used in combination with applied cooling methods to preserve superficial skin layers during cosmetic surgery. Similarly, combined laser irradiation and tissue cooling may also allow development of minimally invasive laser therapies beyond dermatology. This study compares diffusing, side-firing, and radial delivery laser balloon catheter designs for creation of subsurface lesions in tissue, ex vivo, using a near-IR laser and applied contact cooling. An Ytterbium fiber laser with 1075 nm wavelength delivered energy through custom built 18 Fr (6-mm-OD) balloon catheters incorporating either 10-mm-long diffusing fiber tip, 90 degree side-firing fiber, or radial delivery cone mirror, through a central lumen. A chilled solution was flowed through a separate lumen into 9-mm-diameter balloon to keep probe cooled at 7°C. Porcine liver tissue samples were used as preliminary tissue model for immediate observation of thermal lesion creation. The diffusing fiber produced subsurface thermal lesions measuring 49.3 +/- 10.0 mm2 and preserved 0.8 +/- 0.1 mm of surface tissue. The side-firing fiber produced subsurface thermal lesions of 2.4 +/- 0.9 mm2 diameter and preserved 0.5 +/- 0.1 mm of surface tissue. The radial delivery probe assembly failed to produce subsurface thermal lesions, presumably due to the small effective spot diameter at the tissue surface, which limited optical penetration depth. Optimal laser power and irradiation time measured 15 W and 100 s for diffusing fiber and 1.4 W and 20 s, for side-firing fiber, respectively. Diffusing and side-firing laser balloon catheter designs provided subsurface thermal lesions in tissue. However, the divergent laser beam in both designs limited the ability to preserve a thicker layer of tissue surface. Further optimization of laser and cooling parameters may be necessary to preserve thicker surface tissue layers.

  10. Lattice radial quantization: 3D Ising

    Energy Technology Data Exchange (ETDEWEB)

    Brower, R.C., E-mail: brower@bu.edu [Department of Physics, Boston University, Boston, MA 02215 (United States); Fleming, G.T., E-mail: george.fleming@yale.edu [Department of Physics, Yale University, New Haven, CT 06520 (United States); Neuberger, H., E-mail: neuberg@physics.rutgers.edu [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08855 (United States)

    2013-04-25

    Lattice radial quantization is introduced as a nonperturbative method intended to numerically solve Euclidean conformal field theories that can be realized as fixed points of known Lagrangians. As an example, we employ a lattice shaped as a cylinder with a 2D Icosahedral cross-section to discretize dilatations in the 3D Ising model. Using the integer spacing of the anomalous dimensions of the first two descendants (l=1,2), we obtain an estimate for η=0.034(10). We also observed small deviations from integer spacing for the 3rd descendant, which suggests that a further improvement of our radial lattice action will be required to guarantee conformal symmetry at the Wilson–Fisher fixed point in the continuum limit.

  11. Intelligent System for Radial Distribution Load Flow

    Directory of Open Access Journals (Sweden)

    Vaishali Holkar

    2012-10-01

    Full Text Available This paper shows an application of Artificial Neural Networks (ANNs to determine the bus voltages and phase angles of a radial distribution system, without executing the complicated load flow algorithm, for any given load. The performance of the conventional load flow methods such as Newtoh-Raphson load flow, Fast decoupled load flow is found to be very poor under critical conditions such as high R/X ratio, heavily loading condition etc.To overcome the limitations of these regularly used methods a simple and reliable ladder iterative technique is used for solving the power balance equations of radial distribution system (RDS. The proposed method make use of a multi-layer feed forward ANN with error back propagation learning algorithm for calculation of bus voltages and its angles. A sample IEEE 33-bus is extensively tested with the proposed ANN based approach indicating its viability for RDS load flow assessment and results are presented.

  12. Singularities in gravitational collapse with radial pressure

    CERN Document Server

    Gonçalves, S M C V; Goncalves, Sergio M. C. V.; Jhingan, Sanjay

    2001-01-01

    We analyze spherical dust collapse with non-vanishing radial pressure, $\\Pi$, and vanishing tangential stresses. Considering a barotropic equation of state, $\\Pi=\\gamma\\rho$, we obtain an analytical solution in closed form---which is exact for $\\gamma=-1,0$, and approximate otherwise---near the center of symmetry (where the curvature singularity forms). We study the formation, visibility, and curvature strength of singularities in the resulting spacetime. We find that visible, Tipler strong singularities can develop from generic initial data. Radial pressure alters the spectrum of possible endstates for collapse, increasing the parameter space region that contains no visible singularities, but cannot by itself prevent the formation of visible singularities for sufficiently low values of the energy density. Known results from pressureless dust are recovered in the $\\gamma=0$ limit.

  13. Radial localization of odors by human newborns.

    Science.gov (United States)

    Rieser, J; Yonas, A; Wikner, K

    1976-09-01

    To study sensitivity to radial location of an odor source, 20 human newborns, ranging from 16 to 130 hours of age, were presented with a small amount of ammonium hydroxide. The odor source was placed near the nose slightly to the left or right of midline, with its position randomized over repeated trails. Direction of headturn with respect to the odor location and diffuse motor activity were scored from the videotape recordings of the newborns' behavior. It was found that as a group, the newborns turned away from the odor source more frequently than they turned toward it. The tendency to turn away from the odor was stronger in infants who displayed less motor activity after the response. Newborns also exhibited a right bias in the direction of the head movements. It is concluded that a spatially appropriate avoidance response is present in the neonate and that the newborn is innately sensitive to the radial location of an odor.

  14. Radial interchange motions of plasma filaments

    DEFF Research Database (Denmark)

    Garcia, O.E.; Bian, N.H.; Fundamenski, W.

    2006-01-01

    Radial convection of isolated filamentary structures due to interchange motions in magnetized plasmas is investigated. Following a basic discussion of vorticity generation, ballooning, and the role of sheaths, a two-field interchange model is studied by means of numerical simulations...... on a biperiodic domain perpendicular to the magnetic field. It is demonstrated that a blob-like plasma structure develops dipolar vorticity and electrostatic potential fields, resulting in rapid radial acceleration and formation of a steep front and a trailing wake. While the dynamical evolution strongly depends...... as the acoustic speed times the square root of the structure size relative to the length scale of the magnetic field. The plasma filament eventually decelerates due to mixing and collisional dissipation. Finally, the role of sheath dissipation is investigated. When included in the simulations, it significantly...

  15. Radial velocity eclipse mapping of exoplanets

    CERN Document Server

    Nikolov, Nikolay

    2015-01-01

    Planetary rotation rates and obliquities provide information regarding the history of planet formation, but have not yet been measured for evolved extrasolar planets. Here we investigate the theoretical and observational perspective of the Rossiter-McLauglin effect during secondary eclipse (RMse) ingress and egress for transiting exoplanets. Near secondary eclipse, when the planet passes behind the parent star, the star sequentially obscures light from the approaching and receding parts of the rotating planetary surface. The temporal block of light emerging from the approaching (blue-shifted) or receding (red-shifted) parts of the planet causes a temporal distortion in the planet's spectral line profiles resulting in an anomaly in the planet's radial velocity curve. We demonstrate that the shape and the ratio of the ingress-to-egress radial velocity amplitudes depends on the planetary rotational rate, axial tilt and impact factor (i.e. sky-projected planet spin-orbital alignment). In addition, line asymmetrie...

  16. Radial plasma transport in Saturn's magnetosphere (Invited)

    Science.gov (United States)

    Hill, T. W.

    2010-12-01

    Radial plasma transport in the magnetosphere of Saturn, like that of Jupiter, is driven by the centrifugal force of (partial) corotation acting on internally generated plasma. A significant difference is that the internal plasma source is evidently broadly distributed throughout the inner magnetosphere of Saturn (4 CAPS and MAG), and reproduced in numerical simulations (RCM) that contain a distributed plasma source, although it has not, to my knowledge, been explained by an analytical theory containing an active plasma source. Both planets exhibit strong magnetospheric modulations near the planetary spin period, probably indicating a persistent longitudinal asymmetry of the radial plasma transport process. At Jupiter such an asymmetry is readily understood as a consequence of the dramatic asymmetry of the intrinsic planetary magnetic field. This is not so at Saturn, where any such field asymmetry is known to be very modest at best. In neither case has the precise nature of the asymmetry been identified either observationally or theoretically.

  17. THE COOLING OF CORONAL PLASMAS. IV. CATASTROPHIC COOLING OF LOOPS

    Energy Technology Data Exchange (ETDEWEB)

    Cargill, P. J. [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Bradshaw, S. J., E-mail: p.cargill@imperial.ac.uk [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States)

    2013-07-20

    We examine the radiative cooling of coronal loops and demonstrate that the recently identified catastrophic cooling is due to the inability of a loop to sustain radiative/enthalpy cooling below a critical temperature, which can be >1 MK in flares, 0.5-1 MK in active regions, and 0.1 MK in long tenuous loops. Catastrophic cooling is characterized by a rapid fall in coronal temperature, while the coronal density changes by a small amount. Analytic expressions for the critical temperature are derived and show good agreement with numerical results. This effect considerably limits the lifetime of coronal plasmas below the critical temperature.

  18. Cooling Performance of an Impingement Cooling Device Combined with Pins

    Institute of Scientific and Technical Information of China (English)

    Dongliang QUAN; Songling LIU; Jianghai LI; Gaowen LIU

    2005-01-01

    Experimental study and one dimensional model analysis were conducted to investigate cooling performance of an integrated impingement and pin fin cooling device. A typical configuration specimen was made and tested in a large scale low speed closed-looped wind tunnel. Detailed two-dimensional contour maps of the temperature and cooling effectiveness were obtained for different pressure ratios and therefore different coolant flow-rates through the tested specimen. The experimental results showed that very high cooling effectiveness can be achieved by this cooling device with relatively small amount of coolant flow. Based on the theory of transpiration cooling in porous material, a one dimensional heat transfer model was established to analyze the effect of various parameters on cooling effectiveness. It was found from this model that the variation of heat transfer on the gas side, including heat transfer coefficient and film cooling effectiveness, of the specimen created much more effect on its cooling effectiveness than that of the coolant side. The predictions of the one-dimensional mode were compared and agreed well with the experimental data.

  19. Influence of cooling on lava-flow dynamics

    Science.gov (United States)

    Stasiuk, Mark V.; Jaupart, Claude; Stephen, R.; Sparks, J.

    1993-04-01

    Experiments have been carried out to determine the effects of cooling on the flow of fluids with strongly temperature dependent viscosity. Radial viscous-gravity currents of warm glucose syrup were erupted at constant rate into a flat tank filled with a cold aqueous solution. Cold, viscous fluid accumulates at the leading edge, altering the flow shape and thickness and slowing the spreading. The flows attain constant internal temperature distributions and bulk viscosities. The value of the bulk viscosity depends on the Péclet number, which reflects the advective and diffusive heat transport properties of the flow, the flow skin viscosity, which reflects cooling, and the eruption viscosity. Our results explain why most lava flows have bulk viscosities much higher than the lava eruption viscosity. The results can be applied to understanding dynamic lava features such as flow-front thickening, front avalanches, and welded basal breccias.

  20. Lattice Radial Quantization: 3D Ising

    CERN Document Server

    Brower, Richard; Neuberger, Herbert

    2012-01-01

    Lattice radial quantization is introduced as a nonperturbative method intended to numerically solve Euclidean conformal field theories that can be realized as fixed points of known Lagrangians. As an example, we employ a lattice shaped as a cylinder with a 2D Icosahedral cross-section to discretize dilatations in the 3D Ising model. Using this method, we obtain the preliminary estimate eta=0.034(10).

  1. Neurons with radial basis like rate functions.

    Science.gov (United States)

    Kovács, Zsolt László

    2005-01-01

    Artificial neural networks constructed with "locally tuned processing units" and more generally referred to as "radial basis function networks" have been proposed by a number of workers. In this communication, I submit a conjecture, based on indirect experimental and direct computational evidence of the Hodgkin-Huxley model, that there may be biological neurons in nervous systems for which the rate function is locally tuned. If proved to be valid, this conjecture may simplify neurodynamic models of some functions of nervous systems.

  2. Dynamic balancing with rotating radial electromagnetic force

    Institute of Scientific and Technical Information of China (English)

    李勇; 陆永平

    2004-01-01

    A method of producing rotating radial electromagnetic force with a separable structure is proposed,and an experimental model was designed on which open loop vibration control experiments were carried out. Experimental results prove that the electromagnetic force designed has a constant magnitude and an uniform speed,and the idea of using an electromagnetic force as an active control in automatic balancing is correct in principle,and practicable in engineering.

  3. The radial velocity experiment (RAVE) : Fourth data release

    NARCIS (Netherlands)

    Kordopatis, G.; Gilmore, G.; Steinmetz, M.; Boeche, C.; Seabroke, G. M.; Siebert, A.; Zwitter, T.; Binney, J.; de Laverny, P.; Recio-Blanco, A.; Williams, M. E. K.; Piffl, T.; Enke, H.; Roeser, S.; Bijaoui, A.; Wyse, R. F. G.; Freeman, K.; Munari, U.; Carrillo, I.; Anguiano, B.; Burton, D.; Campbell, R.; Cass, C. J. P.; Fiegert, K.; Hartley, M.; Parker, Q. A.; Reid, W.; Ritter, A.; Russell, K. S.; Stupar, M.; Watson, F. G.; Bienayme, O.; Bland-Hawthorn, J.; Gerhard, O.; Gibson, B. K.; Grebel, E. K.; Helmi, A.; Navarro, J. F.; Conrad, C.; Famaey, B.; Faure, C.; Just, A.; Kos, J.; Matijevic, G.; McMillan, P. J.; Minchev, I.; Scholz, R.; Sharma, S.; Siviero, A.; de Boer, E. Wylie; Zerjal, M.

    2013-01-01

    We present the stellar atmospheric parameters (effective temperature, surface gravity, overall metallicity), radial velocities, individual abundances, and distances determined for 425,561 stars, which constitute the fourth public data release of the RAdial Velocity Experiment (RAVE). The stellar atm

  4. Nonrelativistic limit of solution of radial quasipotential equations

    Energy Technology Data Exchange (ETDEWEB)

    Minh, Vu.X.; Kadyshevskii, V.G.; Zhidkov, E.P.

    1986-10-01

    For the S-wave case, solutions of relativistic radial quasipotential equations that degenerate in the limit c ..-->.. infinity into the Jost solutions of the corresponding nonrelativistic radial Schrodinger equations are found.

  5. The Radial Velocity Experiment (RAVE): Fourth Data Release

    NARCIS (Netherlands)

    Kordopatis, G.; Gilmore, G.; Steinmetz, M.; Boeche, C.; Seabroke, G. M.; Siebert, A.; Zwitter, T.; Binney, J.; de Laverny, P.; Recio-Blanco, A.; Williams, M. E. K.; Piffl, T.; Enke, H.; Roeser, S.; Bijaoui, A.; Wyse, R. F. G.; Freeman, K.; Munari, U.; Carrillo, I.; Anguiano, B.; Burton, D.; Campbell, R.; Cass, C. J. P.; Fiegert, K.; Hartley, M.; Parker, Q. A.; Reid, W.; Ritter, A.; Russell, K. S.; Stupar, M.; Watson, F. G.; Bienaymé, O.; Bland-Hawthorn, J.; Gerhard, O.; Gibson, B. K.; Grebel, E. K.; Helmi, A.; Navarro, J. F.; Conrad, C.; Famaey, B.; Faure, C.; Just, A.; Kos, J.; Matijevič, G.; McMillan, P. J.; Minchev, I.; Scholz, R.; Sharma, S.; Siviero, A.; de Boer, E. Wylie; Žerjal, M.

    2013-01-01

    We present the stellar atmospheric parameters (effective temperature, surface gravity, overall metallicity), radial velocities, individual abundances, and distances determined for 425,561 stars, which constitute the fourth public data release of the RAdial Velocity Experiment (RAVE). The stellar atm

  6. Development of a Radial Deconsolidation Method

    Energy Technology Data Exchange (ETDEWEB)

    Helmreich, Grant W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Fred C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    A series of experiments have been initiated to determine the retention or mobility of fission products* in AGR fuel compacts [Petti, et al. 2010]. This information is needed to refine fission product transport models. The AGR-3/4 irradiation test involved half-inch-long compacts that each contained twenty designed-to-fail (DTF) particles, with 20-μm thick carbon-coated kernels whose coatings were deliberately fabricated such that they would crack under irradiation, providing a known source of post-irradiation isotopes. The DTF particles in these compacts were axially distributed along the compact centerline so that the diffusion of fission products released from the DTF kernels would be radially symmetric [Hunn, et al. 2012; Hunn et al. 2011; Kercher, et al. 2011; Hunn, et al. 2007]. Compacts containing DTF particles were irradiated at Idaho National Laboratory (INL) at the Advanced Test Reactor (ATR) [Collin, 2015]. Analysis of the diffusion of these various post-irradiation isotopes through the compact requires a method to radially deconsolidate the compacts so that nested-annular volumes may be analyzed for post-irradiation isotope inventory in the compact matrix, TRISO outer pyrolytic carbon (OPyC), and DTF kernels. An effective radial deconsolidation method and apparatus appropriate to this application has been developed and parametrically characterized.

  7. Radial transport of dust in spiral galaxies

    CERN Document Server

    Vorobyov, E I; Shchekinov, Yu. A.

    2006-01-01

    Motivated by recent observations which detect dust at large galactocentric distances in the disks of spiral galaxies, we propose a mechanism of outward radial transport of dust by spiral stellar density waves. We consider spiral galaxies in which most of dust formation is localized inside the corotation radius. We show that in the disks of such spiral galaxies, the dust grains can travel over radial distances that exceed the corotation radius by roughly 25%. A fraction of the dust grains can be trapped on kidney-shaped stable orbits between the stellar spiral arms and thus can escape the destructive effect of supernova explosions. These grains form diffuse dusty spiral arms, which stretch 4-5 kpc from the sites of active star formation. About 10% of dust by mass injected inside corotation, can be transported over radial distances 3-4 kpc during approximately 1.0 Gyr. This is roughly an order of magnitude more efficient than can be provided by the turbulent motions.

  8. Fast Radial Flows in Transition Disk Holes

    CERN Document Server

    Rosenfeld, Katherine A; Andrews, Sean M

    2013-01-01

    Protoplanetary "transition" disks have large, mass-depleted central cavities, yet also deliver gas onto their host stars at rates comparable to disks without holes. The paradox of simultaneous transparency and accretion can be explained if gas flows inward at much higher radial speeds inside the cavity than outside the cavity, since surface density (and by extension optical depth) varies inversely with inflow velocity at fixed accretion rate. Radial speeds within the cavity might even have to approach free-fall values to explain the huge surface density contrasts inferred for transition disks. We identify observational diagnostics of fast radial inflow in channel maps made in optically thick spectral lines. Signatures include (1) twisted isophotes in maps made at low systemic velocities and (2) rotation of structures observed between maps made in high-velocity line wings. As a test case, we apply our new diagnostic tools to archival ALMA data on the transition disk HD 142527, and uncover evidence for free-fal...

  9. Radial forearm free flap pharyngoesophageal reconstruction.

    Science.gov (United States)

    Azizzadeh, B; Yafai, S; Rawnsley, J D; Abemayor, E; Sercarz, J A; Calcaterra, T C; Berke, G S; Blackwell, K E

    2001-05-01

    This study evaluates the outcome of pharyngoesophageal reconstruction using radial forearm free flaps with regard to primary wound healing, speech, and swallowing in patients requiring laryngopharyngectomy. Retrospective review in the setting of a tertiary, referral, and academic center. Twenty patients underwent reconstruction of the pharyngoesophageal segment using fasciocutaneous radial forearm free flaps. All free flap transfers were successful. An oral diet was resumed in 85% of the patients after surgery. Postoperative pharyngocutaneous fistulas occurred in 4 patients (20%) with 3 resolving spontaneously. Distal strictures also occurred in 20% of the patients. Five patients who underwent tracheoesophageal puncture achieved useful speech. Advantages of radial forearm free flaps for microvascular pharyngoesophageal function include high flap reliability, limited donor site morbidity, larger vascular pedicle caliber, and the ability to achieve good quality tracheoesophageal speech. The swallowing outcome is similar to that achieved after jejunal flap pharyngoesophageal reconstruction. The main disadvantage of this technique relates to a moderately high incidence of pharyngocutaneous fistulas, which contributes to delayed oral intake in affected patients.

  10. NEW RADIAL SYSTEMS OF DARK GLOBULES

    Directory of Open Access Journals (Sweden)

    A. L. Gyulbudaghian

    2015-01-01

    Full Text Available Presentamos los resultados de una inspecci ́on sistem ́atic a de las placas ESO/SRC del hemisferio sur realizada con el prop ́osito de de scubrir nuevos sistemas radiales de gl ́obulos oscuros. Durante esta inspecci ́on en contramos 16 sistemas ra- diales de tipo 1 y 6 sistemas de tipo 2. Con esto, se duplica el n ́umero de sistemas radiales conocidos. En la zona central de los sistemas de tip o 1 se encuentran es- trellas de tipo espectral O − B2, mientras que los sistemas de tipo 2 no exhiben estrellas de tipo temprano en sus centros. Proponemos una in terpretaci ́on tentativa de los grupos de cuerpos condensados submilim ́etricos que n o poseen una contra- parte estelar como sistemas radiales de gl ́obulos oscuros s ituados detr ́as de nubes oscuras gruesas, lo que explicar ́ıa por qu ́e estos gl ́obulo s se observan solamente en longitudes de onda submilim ́etricas.

  11. Electronic cooling using thermoelectric devices

    Energy Technology Data Exchange (ETDEWEB)

    Zebarjadi, M., E-mail: m.zebarjadi@rutgers.edu [Department of Mechanical and Aerospace Engineering, Rutgers University, Piscataway, New Jersey 08854 (United States); Institute of Advanced Materials, Devices, and Nanotechnology, Rutgers University, Piscataway, New Jersey 08854 (United States)

    2015-05-18

    Thermoelectric coolers or Peltier coolers are used to pump heat in the opposite direction of the natural heat flux. These coolers have also been proposed for electronic cooling, wherein the aim is to pump heat in the natural heat flux direction and from hot spots to the colder ambient temperature. In this manuscript, we show that for such applications, one needs to use thermoelectric materials with large thermal conductivity and large power factor, instead of the traditionally used high ZT thermoelectric materials. We further show that with the known thermoelectric materials, the active cooling cannot compete with passive cooling, and one needs to explore a new set of materials to provide a cooling solution better than a regular copper heat sink. We propose a set of materials and directions for exploring possible materials candidates suitable for electronic cooling. Finally, to achieve maximum cooling, we propose to use thermoelectric elements as fins attached to copper blocks.

  12. Optical stochastic cooling in Tevatron

    CERN Document Server

    Lebedev, V

    2012-01-01

    Intrabeam scattering is the major mechanism resulting in a growth of beam emittances and fast luminosity degradation in the Tevatron. As a result in the case of optimal collider operation only about 40% of antiprotons are used to the store end and the rest are discarded. Beam cooling is the only effective remedy to increase the particle burn rate and, consequently, the luminosity. Unfortunately neither electron nor stochastic cooling can be effective at the Tevatron energy and bunch density. Thus the optical stochastic cooling (OSC) is the only promising technology capable to cool the Tevatron beam. Possible ways of such cooling implementation in the Tevatron and advances in the OSC cooling theory are discussed in this paper. The technique looks promising and potentially can double the average Tevatron luminosity without increasing its peak value and the antiproton production.

  13. Numerical Simulation of Modified Radial Electric Field by LHCD

    Institute of Scientific and Technical Information of China (English)

    Wei Wei; Ding Bojiang; Kuang Guangli

    2005-01-01

    Based on the electron's radial force equilibrium, the profiles of radial electric field in OH and LHCD phase are calculated by using a simulation code. The dependences of radial electron field on electron density and its profile and different current ratio, Irf/Ip, are given. The connections between the improvement of plasma confinement and the modified radial electric field by LHCD are discussed by comparing the calculated results with the experimental results.

  14. Preliminary design and R&D of ITER diagnostic-radial X-ray camera

    Science.gov (United States)

    Hu, L.; Chen, K.; Chen, Y.; Cao, H.; Li, S.; Yu, H.; Zhan, J.; Shen, J.; Qin, S.; Sheng, X.; Zhao, J.; Niu, L.; Feng, C.; Ge, J.; Zhang, S.; Zhang, B.

    2017-10-01

    Preliminary design of ITER Radial X-ray Camera (RXC) has been finished. The structure design is optimized and installation process is studied considering the simplification and easiness of maintenance. Remote handling procedures are designed for the system maintenance after being activated. For detector cooling against high environment temperature which can be up to 240°, a dedicated gas cooling system using heat exchanger is designed. The structure analysis indicates that the stresses and displacements of most of the components under load combinations are within the allowable limits and no Safety Important Component (SIC) boundary is damaged. Through putting B4C material in the front part of DSM and around detectors for neutron shielding, the detectors are expected to survive the whole D-D phase. As for electronics, preliminary design of highly integrated pre-amplifier and program controllable mid-amplifier has been completed, both with bandwidth greater than 100 kHz to meet time resolution requirement of 20 kHz. To protect the electronics from intensive neutron and gamma irradiation, shielding cabinet capable of attenuating neutron flux down to 0.0001 and gamma dose 0.01 is designed. Besides, many R&D has been done to support the design. The tests of pre-amplifier and mid-amplifier indicated the electronics had no functional problem when debugging together and generally passed preliminary ElectroMagnetic Compatibility (EMC) test and nuclear test. The highly-integrated compact pre-amplifier has been used in EAST and proved useful. To test the feasibility of dedicated gas cooling system for detectors, a cooling test platform was built and preliminary cooling test has been done, indicating that during 250°baking the detector temperature is promising to be cooled down to the detector temperature limit of 75°. To increase signal to noise ratio, large area detector with dark current less than 2nA has been manufactured and worked steadily in EAST experiments.

  15. Electron Cooling Experiments in CSR

    CERN Document Server

    Xiaodong, Yang

    2011-01-01

    The six species heavy ion beam was accumulated with the help of electron cooling in the main ring of Cooler Storage Ring of Heavy Ion Research Facility in Lanzhou(HIRFL-CSR), the ion beam accumulation dependence on the parameters of cooler was investigated experimentally. The 400MeV/u 12C6+ and 200MeV/u 129Xe54+ was stored and cooled in the experimental ring CSRe, the cooling force was measured in different condition.

  16. Radiative cooling for thermophotovoltaic systems

    Science.gov (United States)

    Zhou, Zhiguang; Sun, Xingshu; Bermel, Peter

    2016-09-01

    Radiative cooling has recently garnered a great deal of attention for its potential as an alternative method for photovoltaic thermal management. Here, we will consider the limits of radiative cooling for thermal management of electronics broadly, as well as a specific application to thermal power generation. We show that radiative cooling power can increase rapidly with temperature, and is particularly beneficial in systems lacking standard convective cooling. This finding indicates that systems previously operating at elevated temperatures (e.g., 80°C) can be passively cooled close to ambient under appropriate conditions with a reasonable cooling area. To examine these general principles for a previously unexplored application, we consider the problem of thermophotovoltaic (TPV) conversion of heat to electricity via thermal radiation illuminating a photovoltaic diode. Since TPV systems generally operate in vacuum, convective cooling is sharply limited, but radiative cooling can be implemented with proper choice of materials and structures. In this work, realistic simulations of system performance are performed using the rigorous coupled wave analysis (RCWA) techniques to capture thermal emitter radiation, PV diode absorption, and radiative cooling. We subsequently optimize the structural geometry within realistic design constraints to find the best configurations to minimize operating temperature. It is found that low-iron soda-lime glass can potentially cool the PV diode by a substantial amount, even to below ambient temperatures. The cooling effect can be further improved by adding 2D-periodic photonic crystal structures. We find that the improvement of efficiency can be as much as an 18% relative increase, relative to the non-radiatively cooled baseline, as well as a potentially significant improvement in PV diode lifetime.

  17. To Be Cool or Uncool?

    Institute of Scientific and Technical Information of China (English)

    袁会珍

    2007-01-01

    The western world has always been divided into two types of people-the cool and the uncool. It is a division that __1__ in school. The cool kids are good at __2__. They are __3__ with the opposite sex. They are good-looking and people want to __4__ their style. They can do their homework but they don't make a big effort. That would __5__ be cool.

  18. Electron cooling experiments in CSR

    Institute of Scientific and Technical Information of China (English)

    PARKHOMCHUK; Vasily; REVA; Vladimir

    2011-01-01

    The six species heavy ion beam was accumulated with the help of electron cooling in the main ring of Cooler Storage Ring of Heavy Ion Research Facility in Lanzhou (HIRFL-CSR). The ion beam accumulation dependence on the parameters of cooler was investigated experimentally. The 400 MeV/u 12C6+ and 200 MeV/u 129Xe54+ were stored and cooled in the experimental ring CSRe, and the cooling force was measured in different conditions.

  19. Workshop 4 Converter cooling & recuperation

    Science.gov (United States)

    Iles, Peter; Hindman, Don

    1995-01-01

    Cooling the PV converter increases the overall TPV system efficiency, and more than offsets the losses incurred in providing cooling systems. Convective air flow methods may be sufficient, and several standard water cooling systems, including thermo-syphon radiators, capillary pumps or microchannel plates, are available. Recuperation is used to increase system efficiency, rather than to increase the emitter temperature. Recuperators operating at comparable high temperatures, such as in high temperature turbines have worked effectively.

  20. Stochastic cooling technology at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Pasquinelli, R.J. E-mail: pasquin@fnal.gov

    2004-10-11

    The first antiproton cooling systems were installed and commissioned at Fermilab in 1984-1985. In the interim period, there have been several major upgrades, system improvements, and complete reincarnation of cooling systems. This paper will present some of the technology that was pioneered at Fermilab to implement stochastic cooling systems in both the Antiproton Source and Recycler accelerators. Current performance data will also be presented.

  1. 21 CFR 866.4800 - Radial immunodiffusion plate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radial immunodiffusion plate. 866.4800 Section 866....4800 Radial immunodiffusion plate. (a) Identification. A radial immunodiffusion plate for clinical use is a device that consists of a plastic plate to which agar gel containing antiserum is added. In...

  2. Direct cooled power electronics substrate

    Science.gov (United States)

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Lowe, Kirk T [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  3. Cooling clothing utilizing water evaporation

    DEFF Research Database (Denmark)

    Sakoi, Tomonori; Tominaga, Naoto; Melikov, Arsen Krikor

    2014-01-01

    We developed cooling clothing that utilizes water evaporation to cool the human body and has a mechanism to control the cooling intensity. Clean water was supplied to the outer surface of the T-shirt of the cooling clothing, and a small fan was used to enhance evaporation on this outer surface...... temperature ranging from 27.4 to 30.7 °C to establish a suitable water supply control method. A water supply control method that prevents water accumulation in the T-shirt and water dribbling was validated; this method is established based on the concept of the water evaporation capacity under the applied...

  4. Regeneratively Cooled Porous Media Jacket

    Science.gov (United States)

    Mungas, Greg (Inventor); Fisher, David J. (Inventor); London, Adam Pollok (Inventor); Fryer, Jack Merrill (Inventor)

    2013-01-01

    The fluid and heat transfer theory for regenerative cooling of a rocket combustion chamber with a porous media coolant jacket is presented. This model is used to design a regeneratively cooled rocket or other high temperature engine cooling jacket. Cooling jackets comprising impermeable inner and outer walls, and porous media channels are disclosed. Also disclosed are porous media coolant jackets with additional structures designed to transfer heat directly from the inner wall to the outer wall, and structures designed to direct movement of the coolant fluid from the inner wall to the outer wall. Methods of making such jackets are also disclosed.

  5. On the Nature of Feedback Heating in Cooling Flow Clusters

    CERN Document Server

    Pizzolato, F; Pizzolato, Fabio; Soker, Noam

    2004-01-01

    We study the feedback between heating and cooling of the intra-cluster medium (ICM) in cooling flow (CF) galaxies and clusters. We adopt the popular view that the heating is due to an active galactic nucleus (AGN), i.e. a central black hole accreting mass and launching jets and/or winds. We propose that the feedback occurs with the entire cool inner region (r2 cool fast and are removed from the ICM before experiencing the next major AGN heating event. We term this scenario cold-feedback. Some of these blobs cool and sink toward the central black hole, while others might form stars and cold molecular clouds. We derive the conditions under which the dense blobs formed by perturbations might cool to low temperatures (T < 10^4 K), and feed the black hole. The main conditions are found to be: (1) An over-dense blob must be prevented from reaching an equilibrium position in the ICM: therefore it has to cool fast, and the density profile of the ambient gas should be shallow; (2) Non-linear perturbations are requi...

  6. Fluid cooled electrical assembly

    Science.gov (United States)

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

    A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

  7. ATLAS' major cooling project

    CERN Multimedia

    2005-01-01

    In 2005, a considerable effort has been put into commissioning the various units of ATLAS' complex cryogenic system. This is in preparation for the imminent cooling of some of the largest components of the detector in their final underground configuration. The liquid helium and nitrogen ATLAS refrigerators in USA 15. Cryogenics plays a vital role in operating massive detectors such as ATLAS. In many ways the liquefied argon, nitrogen and helium are the life-blood of the detector. ATLAS could not function without cryogens that will be constantly pumped via proximity systems to the superconducting magnets and subdetectors. In recent weeks compressors at the surface and underground refrigerators, dewars, pumps, linkages and all manner of other components related to the cryogenic system have been tested and commissioned. Fifty metres underground The helium and nitrogen refrigerators, installed inside the service cavern, are an important part of the ATLAS cryogenic system. Two independent helium refrigerators ...

  8. CARMENES ultra-stable cooling system: very promising results

    Science.gov (United States)

    Mirabet, E.; Carvas, P.; Lizon, J.-L.; Becerril, S.; Rodríguez, E.; Abril, M.; Cárdenas, M. C.; Morales, R.; Pérez, D.; Sánchez Carrasco, M. A.; Amado, P. J.; Seifert, W.; Quirrenbach, A.; Caballero, J. A.; Ribas, I.; Reiners, A.; Dreizler, S.

    2014-07-01

    CARMENES is a high resolution spectrograph to detect planets through the variation of radial velocity, destined for the Calar Alto Observatory in Almeria, Spain. The optical bench has a working temperature of 140K with a 24 hours stability of ±0,1K; goal ±0,01K. It is enclosed with a radiation shield actively cooled with thermalized nitrogen gas that flows through strategically positioned heat exchangers to remove its radiative load. The cooling system has an external preparation unit (N2GPU), which provides the nitrogen gas through actively vaporizing liquid nitrogen with heating resistances and a three stage circuit flow, each one controlled by an independent PID. Since CARMENES is still in the construction phase, a dedicated test facility has been built in order to simulate the instrument and correctly establish the N2GPU parameters. Furthermore, the test facility allows a wide range of configurations set-ups, which enables a full characterization of the N2GPU and the cooling system. The N2GPU has been designed to offer a wide temperature range of thermally stabilized nitrogen gas flow, which apart from CARMENES could also be used to provide ultra-high thermal stability in other cryogenic instruments. The present paper shows the testing of the cooling performance, the hardware used and the very promising results obtained.

  9. Cooling Requirements for the Vertical Shear Instability in Protoplanetary Disks

    CERN Document Server

    Lin, Min-Kai

    2015-01-01

    It is difficult to understand how cold circumstellar disks accrete onto their central stars. A hydrodynamic mechanism, the vertical shear instability (VSI), offers a means to drive angular momentum transport in cold accretion disks such as protoplanetary disks (PPDs). The VSI is driven by a weak vertical gradient in the disk's orbital motion. In order to grow, the VSI must overcome vertical buoyancy, a strongly stabilizing influence in cold disks, where heating is dominated by external irradiation. Rapid cooling, via radiative losses, reduces the effective buoyancy and allows the VSI to operate. In this paper, we quantify the cooling timescale, $t_c$, needed for growth of the VSI. We perform a linear analysis of the VSI with cooling in vertically global and radially local disk models. For irradiated disks, we find that the VSI is most vigorous for rapid cooling with $t_c < \\Omega_\\mathrm{K}^{-1} h |q| / (\\gamma -1)$ in terms of the Keplerian orbital frequency, $\\Omega_\\mathrm{K}$, the disk's aspect ratio, ...

  10. Characterising the Gravitational Instability in Cooling Accretion Discs

    CERN Document Server

    Cossins, Peter; Clarke, Cathie

    2008-01-01

    We perform numerical analyses of the structure induced by gravitational instabilities in cooling gaseous accretion discs. For low enough cooling rates a quasi-steady configuration is reached, with the instability saturating at a finite amplitude in a marginally stable disc. We find that the saturation amplitude scales with the inverse square root of the cooling parameter beta = t_cool / t_dyn, which indicates that the heating rate induced by the instability is proportional to the energy density of the induced density waves. We find that at saturation the energy dissipated per dynamical time by weak shocks due is of the order of 20 per cent of the wave energy. From Fourier analysis of the disc structure we find that while the azimuthal wavenumber is roughly constant with radius, the mean radial wavenumber increases with radius, with the dominant mode corresponding to the locally most unstable wavelength. We demonstrate that the density waves excited in relatively low mass discs are always close to co-rotation,...

  11. Air cooled absorption chillers for solar cooling applications

    Science.gov (United States)

    Biermann, W. J.; Reimann, R. C.

    1982-03-01

    The chemical composition of a 'best' absorption refrigerant system is identified, and those properties of the system necessary to design hot water operated, air cooled chilling equipment are determined. Air cooled chillers from single family residential sizes into the commercial rooftop size range are designed and operated.

  12. On the calculation of x-ray scattering signals from pairwise radial distribution functions

    DEFF Research Database (Denmark)

    Dohn, Asmus Ougaard; Biasin, Elisa; Haldrup, Kristoffer;

    2015-01-01

    We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any possi...... possible ambiguities, and the result includes a modification to the atom-type formulation which to our knowledge is previously unaccounted for. The formulation is numerically implemented and validated.......We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any...

  13. A buffer gas cooled beam of barium monohydride

    Science.gov (United States)

    Iwata, Geoffrey; Tarallo, Marco; Zelevinsky, Tanya

    2016-05-01

    Significant advances in direct laser cooling of diatomic molecules have opened up a wide array of molecular species to precision studies spanning many-body physics, quantum collisions and ultracold dissociation. We present a cryogenic beam source of barium monohydride (BaH), and study laser ablation of solid precursor targets as well as helium buffer gas cooling dynamics. Additionally, we cover progress towards a molecular magneto-optical trap, with spectroscopic studies of relevant cooling transitions in the B2 Σ molecules, including resolution of hyperfine structure and precision measurements of the vibrational Frank-Condon factors. Finally, we examine the feasibility of photo dissociation of trapped BaH molecules to yield optically accessible samples of ultracold hydrogen.

  14. Sisyphus Laser Cooling of a Polyatomic Molecule

    CERN Document Server

    Kozyryev, Ivan; Matsuda, Kyle; Augenbraun, Benjamin L; Anderegg, Loic; Sedlack, Alexander P; Doyle, John M

    2016-01-01

    We perform magnetically-assisted Sisyphus laser cooling of the triatomic free radical strontium monohydroxide (SrOH). This is achieved with principal optical cycling in the rotationally closed $P\\left(N"=1\\right)$ branch of either the $\\tilde{X}^{2}\\Sigma^{+}\\left(000\\right)\\leftrightarrow\\tilde{A}^{2}\\Pi_{1/2}\\left(000\\right)$ or the $\\tilde{X}^{2}\\Sigma^{+}\\left(000\\right)\\leftrightarrow\\tilde{B}^{2}\\Sigma^{+}\\left(000\\right)$ vibronic transitions. Molecules lost into the excited vibrational states during the cooling process are repumped back through the $\\tilde{B}\\left(000\\right)$ state for both the $\\left(100\\right)$ level of the Sr-O stretching mode and the $\\left(02^{0}0\\right)$ level of the bending mode. The transverse temperature of a SrOH molecular beam is reduced in one dimension by two orders of magnitude to $\\sim700\\ {\\rm \\mu K}$. This approach opens a path towards creating a variety of ultracold polyatomic molecules, including much larger ones, by means of direct laser cooling.

  15. Sisyphus Laser Cooling of a Polyatomic Molecule.

    Science.gov (United States)

    Kozyryev, Ivan; Baum, Louis; Matsuda, Kyle; Augenbraun, Benjamin L; Anderegg, Loic; Sedlack, Alexander P; Doyle, John M

    2017-04-28

    We perform magnetically assisted Sisyphus laser cooling of the triatomic free radical strontium monohydroxide (SrOH). This is achieved with principal optical cycling in the rotationally closed P(N^{''}=1) branch of either the X[over ˜]^{2}Σ^{+}(000)↔A[over ˜]^{2}Π_{1/2}(000) or the X[over ˜]^{2}Σ^{+}(000)↔B[over ˜]^{2}Σ^{+}(000) vibronic transitions. Molecules lost into the excited vibrational states during the cooling process are repumped back through the B[over ˜](000) state for both the (100) level of the Sr-O stretching mode and the (02^{0}0) level of the bending mode. The transverse temperature of a SrOH molecular beam is reduced in one dimension by 2 orders of magnitude to ∼750  μK. This approach opens a path towards creating a variety of ultracold polyatomic molecules by means of direct laser cooling.

  16. EXPERIMENTAL MEASUREMENT AND NUMERICAL SIMULATION FOR FLOW FIELD AND FILM COOLING EFFECTIVENESS IN FILM-COOLED TURBINE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Numerical simulation of three-dimensional flow field and film cooling effectiveness in film-cooled turbine rotor and stationary turbine cascade were carried out by using the κ-ε turbulence model, and the predictions of the three-dimensional velocities were compared with the measured results by Laser-Doppler Velocimetry (LDV). Results reveal the secondary flow near the blade surface in the wake region behind the jet hole. Compared with the stationary cascade, there are the centrifugal force and Coriolis force existing in the flow field of the turbine rotor, and these forces make the three-dimensional flow field change in the turbine rotor, especially for the radial velocity. The effect of rotation on the flow field and the film cooling effectiveness on the pressure side is more apparent than that on the suction side as is shown in the computational and measured results, and the low film cooling effectiveness appears on the pressure surface of the turbine rotor blade compared with that of the stationary cascade.

  17. The Effects of Radial Compression on Thermal Conductivity of Carbon and Boron Nitride Nanotubes

    OpenAIRE

    Haijun Shen

    2012-01-01

    By using molecular dynamics method, thermal conductivity of (10, 10) carbon and boron nitride (BN) nanotubes under radial compression was investigated, and the - (thermal conductivity versus temperature) curves of the two nanotubes were obtained. It is found that with the increase of temperature the thermal conductivity of two nanotubes decreases; the nanotubes, under both the local compression and whole compression, have lower thermal conductivity, and the larger the compressive deformat...

  18. Feasibility assessment of vacuum cooling followed by immersion vacuum cooling on water-cooked pork.

    Science.gov (United States)

    Dong, Xiaoguang; Chen, Hui; Liu, Yi; Dai, Ruitong; Li, Xingmin

    2012-01-01

    Vacuum cooling followed by immersion vacuum cooling was designed to cool water-cooked pork (1.5±0.05 kg) compared with air blast cooling (4±0.5°C, 2 m/s), vacuum cooling (10 mbar) and immersion vacuum cooling. This combined cooling method was: vacuum cooling to an intermediate temperature of 25°C and then immersion vacuum cooling with water of 10°C to the final temperature of 10°C. It was found that the cooling loss of this combined cooling method was significantly lower (Pvacuum cooling. This combined cooling was faster (Pvacuum cooling in terms of cooling rate. Moreover, the pork cooled by combined cooling method had significant differences (P<0.05) in water content, color and shear force. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Newton's Law of Cooling Revisited

    Science.gov (United States)

    Vollmer, M.

    2009-01-01

    The cooling of objects is often described by a law, attributed to Newton, which states that the temperature difference of a cooling body with respect to the surroundings decreases exponentially with time. Such behaviour has been observed for many laboratory experiments, which led to a wide acceptance of this approach. However, the heat transfer…

  20. Dialogues in the COOL Project

    NARCIS (Netherlands)

    Stalpers, S.I.P.; Kroeze, C.

    2013-01-01

    The Climate Options for the Long-term (COOL) Project is a participatory integrated assessment (PIA) comprising extensive dialogues at three levels: national, European and global. The objective of the COOL Project was to ‘develop strategic notions on how to achieve drastic reductions of greenhouse ga

  1. Be Cool, Man! / Jevgeni Levik

    Index Scriptorium Estoniae

    Levik, Jevgeni

    2005-01-01

    Järg 1995. aasta kriminaalkomöödiale "Tooge jupats" ("Get Shorty") : mängufilm "Be Cool, Chili Palmer on tagasi!" ("Be Cool") : režissöör F. Gary Gray, peaosades J. Travolta ja U. Thurman : USA 2005. Lisatud J. Travolta ja U. Thurmani lühiintervjuud

  2. Temperature initiated passive cooling system

    Science.gov (United States)

    Forsberg, Charles W.

    1994-01-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.

  3. Be Cool, Man! / Jevgeni Levik

    Index Scriptorium Estoniae

    Levik, Jevgeni

    2005-01-01

    Järg 1995. aasta kriminaalkomöödiale "Tooge jupats" ("Get Shorty") : mängufilm "Be Cool, Chili Palmer on tagasi!" ("Be Cool") : režissöör F. Gary Gray, peaosades J. Travolta ja U. Thurman : USA 2005. Lisatud J. Travolta ja U. Thurmani lühiintervjuud

  4. Dew Point Evaporative Comfort Cooling

    Science.gov (United States)

    2012-11-01

    220 Figure 140. Water-cooled chilled water plant with primary/secondary...enough to buffer the space by carrying away solar loads in unoccupied volumes, such as ceiling plenums. For rooftop installations, where ceiling...and are significant for the three-month period and generally exceed 68%. Larger chilled water plants with water-cooled condensers can operate with

  5. Triatomic molecules laser-cooled

    Science.gov (United States)

    2017-06-01

    Molecules containing three atoms have been laser-cooled to ultracold temperatures for the first time. John Doyle and colleagues at Harvard University in the US used a technique called Sisyphus cooling to chill an ensemble of about a million strontium-monohydroxide molecules to 750 μK.

  6. Radial distribution of gas and dust in the two spiral galaxies M99 and M100

    CERN Document Server

    Pohlen, M; Smith, M W L; Eales, S A; Boselli, A; Bendo, G J; Gomez, H L; Papageorgiou, A; Auld, R; Baes, M; Bock, J J; Bradford, M; Buat, V; Castro-Rodriguez, N; Chanial, P; Charlot, S; Ciesla, L; Clements, D L; Cooray, A; Cormier, D; Dwek, E; Eales, S A; Elbaz, D; Galametz, M; Galliano, F; Gear, W K; Glenn, J; Griffin, M; Hony, S; Isaak, K G; Levenson, L R; Lu, N; Madden, S; O'Halloran, B; Okumura, K; Oliver, S; Page, M J; Panuzzo, P; Parkin, T J; Perez-Fournon, I; Rangwala, N; Rigby, E E; Roussel, H; Rykala, A; Sacchi, N; Sauvage, M; Schulz, B; Schirm, M R P; Smith, M W L; Spinoglio, L; Stevens, J A; Srinivasan, S; Symeonidis, M; Trichas, M; Vaccari, M; Vigroux, L; Wilson, C D; Wozniak, H; Wright, G S; Zeiliner, W W

    2010-01-01

    By combining Herschel-SPIRE data with archival Spitzer, HI, and CO maps, we investigate the spatial distribution of gas and dust in the two famous grand-design spirals M99 and M100 in the Virgo cluster. Thanks to the unique resolution and sensitivity of the Herschel-SPIRE photometer, we are for the first time able to measure the distribution and extent of cool, submillimetre (submm)-emitting dust inside and beyond the optical radius. We compare this with the radial variation in both the gas mass and the metallicity. Although we adopt a model-independent, phenomenological approach, our analysis provides important insights. We find the dust extending to at least the optical radius of the galaxy and showing breaks in its radial profiles at similar positions as the stellar distribution. The colour indices f350/f500 and f250/f350 decrease radially consistent with the temperature decreasing with radius. We also find evidence of an increasing gas to dust ratio with radius in the outer regions of both galaxies.

  7. Mini-queratotomía radial VS: queratotomía radial. Reporte preliminar Radial mini-keratotomy vs radial keratotomy: Preliminary report

    Directory of Open Access Journals (Sweden)

    José Pacheco Serrano

    1999-06-01

    Full Text Available Damos a conocer los primeros resultados de la implementación de un nuevo procedimiento quirúrgico para la corrección de la miopía, la mini-queratotomía radial, y su evaluación frente a la queratotomía radial convencional en 25 pacientes en quienes se realizó la técnica convencional en el ojo derecho y la nueva técnica en el izquierdo. Se midieron cuatro variables pre y posoperatorias, a saber, los componentes esférico y cilíndrico de la refracción, la agudeza visual sin corrección y la queratometría central. El método estadístico que se ajusta al estudio muestra que no existen diferencias significativas en los resultados obtenidos por ambos métodos. La nueva técnica constituye una alternativa quirúrgica para pacientes con miopías leves y moderadas. El riesgo de complicaciones postrauma disminuye sustancialmente a causa de que las incisiones tienen menor longitudThe firts results of the implementation of a new surgical procedure for correcting myopia, the mini-racial keratotomy, and its evaluation against conventional radial keratotomy are shown by using the conventional technique in the right eye and the new technique in the left eye of 25 patients. 4 pre-and postoperative variables were measured, mainly, the spherical and cylindrical components of refraction, the acuity and the central keratometry,. The statistical method adjusted to the study proves that there are ni significant differences between the results obtained with both methods. The new technique is a surgical alternative for patients with mild and moderate myopias. The risk for postrauma complications decreases considerably because the incisions have a lower lenght

  8. Bilateral high radial nerve compressions: a case report.

    Science.gov (United States)

    Chuangsuwanich, A; Muangsombut, S; Sangruchi, T

    2000-06-01

    A 40-year-old woman with bilateral high radial nerve compressions by non-traumatic cause was reported. It occurred first at the right radial nerve which was explored after a period of investigation and conservative treatment. Two constricted sites 2.0 cm apart of the right radial nerve crossed by branches of the radial collateral artery beneath the lateral head of the triceps were found. The constricted sites including tissue in between was resected and replaced with a sural nerve graft. One year later the patient had the same episode on the left side. The operative finding was the same as the previous one. Sural nerve graft was performed after neurolysis had failed. The patient's normal radial nerve function returned in one year. This is the first reported case in the literature of bilateral high radial nerve compressions by branches of the radial collateral artery.

  9. Analytical fit of radial velocity data

    CERN Document Server

    Delisle, J -B; Buchschacher, N; Alesina, F

    2015-01-01

    We describe an analytical method for computing the orbital parameters of planets from the periodogram of a radial velocity signal. The method is very efficient and provides a good approximation of the orbital parameters. The accuracy is mainly limited by the accuracy of the computation of the Fourier decomposition of the signal which is sensible to sampling and noise. Our method is complementary with more accurate (and more computer time expensive) numerical algorithms (e.g. Levenberg-Marquardt, MCMC, genetic algorithms). Indeed, the analytical approximation can be used as initial condition to accelerate the convergence of these numerical methods.

  10. Eleven-year Experience with Radial Keratotomy

    Institute of Scientific and Technical Information of China (English)

    Akira; Momose

    1994-01-01

    1 900 consecutive eyes that underwent radial keratotomy by the senior author were evaluated retrospectively. 3 months after surgery, minimum reduction in mean spherical equivalent of 0. 67D was achieved with 1 incision and maximum 7. 250 with 24 incisions. Unconnected visual acuity of 20/40 or better was obtained in 99. 4% of eyes with low myopia, 64. 2% with moderate myopia and 32. 4% with high myopia. For anisometropia, bilateral RK reduced refractive error from -12. 12D to -5. 22D in more myopic eyes...

  11. Radial Keratotomy:Eleven-year Experiences

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    During the period from 1980 to 1991,Radial Keratotomy(RK)hadbeen done by the author under topical anesthesia in more than 10000 cases,mostly on both eyes at the same time.Those patients had myopia with apreoperative refractive error between 1.5 and 20.0 diopters(D).The surgicaltechnique consisted of 4,8,16 incisions using a diamond knife with micrometerand the diameter of the central clear zone was mostly 3.0mm and determinedby preoperative refractive error.Many different procedures were tried to im-pro...

  12. Convex and Radially Concave Contoured Distributions

    Directory of Open Access Journals (Sweden)

    Wolf-Dieter Richter

    2015-01-01

    Full Text Available Integral representations of the locally defined star-generalized surface content measures on star spheres are derived for boundary spheres of balls being convex or radially concave with respect to a fan in Rn. As a result, the general geometric measure representation of star-shaped probability distributions and the general stochastic representation of the corresponding random vectors allow additional specific interpretations in the two mentioned cases. Applications to estimating and testing hypotheses on scaling parameters are presented, and two-dimensional sample clouds are simulated.

  13. A novel electronic cooling concept

    Science.gov (United States)

    Ponnappan, R.; Beam, J. E.

    Advanced electrical power conditioning systems for the More Electric Aircraft Initiative involve high currents and high voltages with the attendant waste heat generation and cooling problems. The use of solid state switching devices such as MCTs for these systems will result in power dissipation of several hundred Watts per square centimeter. Conventional forced air or low velocity single phase fluid cooling is inadequate to handle the waste heat dissipation of these high power devices. More advanced and innovative methods of cooling which can use fluids available in the aircraft and also easy to package are sought. A new approach called 'venturi flow cooling concept' is described. It is shown that localized cooling up to 200 W/sq cm is possible at the venturi throat region where the MCTs can be mounted. PAO coolant with Pr = 56 at 40 C can be conveniently used in aircraft.

  14. Laser cooling to quantum degeneracy.

    Science.gov (United States)

    Stellmer, Simon; Pasquiou, Benjamin; Grimm, Rudolf; Schreck, Florian

    2013-06-28

    We report on Bose-Einstein condensation in a gas of strontium atoms, using laser cooling as the only cooling mechanism. The condensate is formed within a sample that is continuously Doppler cooled to below 1  μK on a narrow-linewidth transition. The critical phase-space density for condensation is reached in a central region of the sample, in which atoms are rendered transparent for laser cooling photons. The density in this region is enhanced by an additional dipole trap potential. Thermal equilibrium between the gas in this central region and the surrounding laser cooled part of the cloud is established by elastic collisions. Condensates of up to 10(5) atoms can be repeatedly formed on a time scale of 100 ms, with prospects for the generation of a continuous atom laser.

  15. Molecular Fountain

    Science.gov (United States)

    Cheng, Cunfeng; van der Poel, Aernout P. P.; Jansen, Paul; Quintero-Pérez, Marina; Wall, Thomas E.; Ubachs, Wim; Bethlem, Hendrick L.

    2016-12-01

    The resolution of any spectroscopic or interferometric experiment is ultimately limited by the total time a particle is interrogated. Here we demonstrate the first molecular fountain, a development which permits hitherto unattainably long interrogation times with molecules. In our experiments, ammonia molecules are decelerated and cooled using electric fields, launched upwards with a velocity between 1.4 and 1.9 m/s and observed as they fall back under gravity. A combination of quadrupole lenses and bunching elements is used to shape the beam such that it has a large position spread and a small velocity spread (corresponding to a transverse temperature of free fall, while being strongly focused at the detection region. The molecules are in free fall for up to 266 ms, making it possible, in principle, to perform sub-Hz measurements in molecular systems and paving the way for stringent tests of fundamental physics theories.

  16. Cooling off with physics

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Chris [Unilever R and D (United Kingdom)

    2003-08-01

    You might think of ice cream as a delicious treat to be enjoyed on a sunny summer's day. However, to the ice-cream scientists who recently gathered in Thessaloniki in Greece for the 2nd International Ice Cream Symposium, it is a complex composite material. Ice cream consists of three dispersed phases: ice crystals, which have a mean size of 50 microns, air bubbles with a diameter of about 70 microns, and fat droplets with a size of 1 micron. These phases are held together by what is called the matrix - not a sci-fi film, but a viscous solution of sugars, milk proteins and polysaccharides. The microstructure, and hence the texture that you experience when you eat ice cream, is created in a freezing process that has remained fundamentally unchanged since the first ice-cream maker was patented in the 1840s. The ingredients - water, milk protein, fat, sugar, emulsifiers, stabilizers, flavours and a lot of air - are mixed together before being pasteurized and homogenized. They are then pumped into a cylinder that is cooled from the outside with a refrigerant. As the mixture touches the cylinder wall it freezes and forms ice crystals, which are quickly scraped off by a rotating blade. The blade is attached to a beater that disperses the ice crystals into the mixture. At the same time, air is injected and broken down into small bubbles by the shear that the beater generates. As the mixture passes along the cylinder, the number of ice crystals increases and its temperature drops. As a result, the viscosity of the mixture increases, so that more energy input is needed to rotate the beater. This energy is dissipated as heat, and when the ice cream reaches about -6 deg. C the energy input through the beater equals the energy removed as heat by the refrigerant. The process therefore becomes self-limiting and it is not possible to cool the ice cream any further. However, at -6 deg. C the microstructure is unstable. The ice cream therefore has to be removed from the freezer

  17. Simulating the Cooling Flow of Cool-Core Clusters

    CERN Document Server

    Li, Yuan

    2011-01-01

    We carry out high-resolution adaptive mesh refinement simulations of a cool core cluster, resolving the flow from Mpc scales down to pc scales. We do not (yet) include any AGN heating, focusing instead on cooling in order to understand how gas gets to the supermassive black hole (SMBH) at the center of the cluster. We find that, as the gas cools, the cluster develops a very flat temperature profile, undergoing a cooling catastrophe only in the central 10-100 pc of the cluster. Outside of this region, the flow is smooth, with no local cooling instabilities, and naturally produces very little low-temperature gas (below a few keV), in agreement with observations. The gas cooling in the center of the cluster rapidly forms a thin accretion disk. The amount of cold gas produced at the very center grows rapidly until a reasonable estimate of the resulting AGN heating rate (assuming even a moderate accretion efficiency) would overwhelm cooling. We argue that this naturally produces a thermostat which links the coolin...

  18. Radially polarized and passively Q-switched Nd:YAG laser with composite structure of gain medium

    Institute of Scientific and Technical Information of China (English)

    Kegui Xia; Jianlang Li

    2011-01-01

    We report on a radially polarized and passively Q-switched Nd:YAG/Cr4+:YAG laser.The bulk Nd:YAG crystal is bonded with two undoped YAG crystal end caps to weaken the thermal lens effect and thus,enhance the extraction of stored energy in the bulk gain material.In the absence of active water cooling,the average laser power reaches 383 mW with 33% slope efficiency,and the laser pulse achieves 1.457-W peak power,18.9-ns duration,and 13.9-kHz repetition rate with 97.6% polarization purity.The radially polarized laser beam shows axial symmetry both in amplitude and polarization[1-3].The beam is applied in a variety of fields[3-8] such as particle trapping and acceleration[5],high-resolution microscopy[6],and material processing (e.g.,metal cutting or drilling).Because radially polarized light is globally of the ptype with respect to the cutting surface,the material absorption to the irradiation could be maximized,the significant effect of the cutting depth and cutting speed can be facilitated[7,8].This advantage has created a high demand for high power and radially polarized lasers.%We report on a radially polarized and passively Q-switched Nd:YAG/Cr4+:YAG laser. The bulk Nd:YAC crystal is bonded with two undoped YAG crystal end caps to weaken the thermal lens effect and thus, enhance the extraction of stored energy in the bulk gain material. In the absence of active water cooling, the average laser power reaches 383 mW with 33% slope efficiency, and the laser pulse achieves 1.457-W peak power, 18.9-ns duration, and 13.9-kHz repetition rate with 97.6% polarization purity.

  19. 46 CFR 153.432 - Cooling systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cooling systems. 153.432 Section 153.432 Shipping COAST... Control Systems § 153.432 Cooling systems. (a) Each cargo cooling system must have an equivalent standby... cooling system. (b) Each tankship that has a cargo tank with a required cooling system must have a manual...

  20. Convective cooling of photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, E.; Gibbons, C. [Energy Engineering Group, Mechanical Engineering Department, Cork Institute of Technology, Bishopstown, Cork (Ireland)

    2004-07-01

    Most solar cells presently on the market are based on silicon wafers, the so-called first generation technology. As this technology has matured costs have become increasingly dominated by material costs. In the last ten years, continuous work has brought the efficiency of standard cells to the 25% region. A switch to second generation or thin film technology cells now seems imminent. Thin film technology eliminates the silicon wafer and offer the prospect of reducing material and manufacturing costs, but they exhibit lower efficiencies of around 10% for a commercial device. Third generation or tandem cells are currently at a 'proof of concept' research level, with a theoretical conversion rate of 86.8% being asserted Whatever the material construction and manufacturing method of cells, the thermal effect of overheating will prevail in the semiconductor and it is accepted that a lowered temperature will bring about an increase in conversion efficiency. The aim of this project is to improve the efficiency of PV electrical output, by convectively cooling the cells through perforations in them. As the cells heat up they lose efficiency. As the panel heats up a loss in efficiency of 0.5% per C increase in temperature has been recorded. (orig.)

  1. Central cooling: absorptive chillers

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1977-08-01

    This technology evaluation covers commercially available single-effect, lithium-bromide absorption chillers ranging in nominal cooling capacities of 3 to 1,660 tons and double-effect lithium-bromide chillers from 385 to 1,060 tons. The nominal COP measured at operating conditions of 12 psig input steam for the single-effect machine, 85/sup 0/ entering condenser water, and 44/sup 0/F exiting chilled-water, ranges from 0.6 to 0.65. The nominal COP for the double-effect machine varies from 1.0 to 1.15 with 144 psig entering steam. Data are provided to estimate absorption-chiller performance at off-nominal operating conditions. The part-load performance curves along with cost estimating functions help the system design engineer select absorption equipment for a particular application based on life-cycle costs. Several suggestions are offered which may be useful for interfacing an absorption chiller with the remaining Integrated Community Energy System. The ammonia-water absorption chillers are not considered to be readily available technology for ICES application; therefore, performance and cost data on them are not included in this evaluation.

  2. Performance of Air-cooled Engine Cylinders Using Blower Cooling

    Science.gov (United States)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1936-01-01

    An investigation was made to obtain information on the minimum quantity of air and power required to cool conventional air cooled cylinders at various operating conditions when using a blower. The results of these tests show that the minimum power required for satisfactory cooling with an overall blower efficiency of 100 percent varied from 2 to 6 percent of the engine power depending on the operating conditions. The shape of the jacket had a large effect on the cylinder temperatures. Increasing the air speed over the front of the cylinder by keeping the greater part of the circumference of the cylinder covered by the jacket reduced the temperatures over the entire cylinder.

  3. Radially Magnetized Protoplanetary Disk: Vertical Profile

    CERN Document Server

    Russo, Matthew

    2015-01-01

    This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, is wound up by the disk shear, and is pushed downward by a combination of turbulent mixing and ambipolar and Ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiences the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field $B_r \\sim (10^{-4}$-$10^{-2})(r/{\\rm AU})^{-2}$ G. Careful attention is giv...

  4. The Interpolation Theory of Radial Basis Functions

    CERN Document Server

    Baxter, Brad

    2010-01-01

    In this dissertation, it is first shown that, when the radial basis function is a $p$-norm and $1 2$. Specifically, for every $p > 2$, we construct a set of different points in some $\\Rd$ for which the interpolation matrix is singular. The greater part of this work investigates the sensitivity of radial basis function interpolants to changes in the function values at the interpolation points. Our early results show that it is possible to recast the work of Ball, Narcowich and Ward in the language of distributional Fourier transforms in an elegant way. We then use this language to study the interpolation matrices generated by subsets of regular grids. In particular, we are able to extend the classical theory of Toeplitz operators to calculate sharp bounds on the spectra of such matrices. Applying our understanding of these spectra, we construct preconditioners for the conjugate gradient solution of the interpolation equations. Our main result is that the number of steps required to achieve solution of the lin...

  5. Weighted Radial Variation for Node Feature Classification

    CERN Document Server

    Andris, C

    2011-01-01

    Connections created from a node-edge matrix have been traditionally difficult to visualize and analyze because of the number of flows to be rendered in a limited feature or cartographic space. Because analyzing connectivity patterns is useful for understanding the complex dynamics of human and information flow that connect non-adjacent space, techniques that allow for visual data mining or static representations of system dynamics are a growing field of research. Here, we create a Weighted Radial Variation (WRV) technique to classify a set of nodes based on the configuration of their radially-emanating vector flows. Each entity's vector is syncopated in terms of cardinality, direction, length, and flow magnitude. The WRV process unravels each star-like entity's individual flow vectors on a 0-360{\\deg} spectrum, to form a unique signal whose distribution depends on the flow presence at each step around the entity, and is further characterized by flow distance and magnitude. The signals are processed with an un...

  6. Spherical radial basis functions, theory and applications

    CERN Document Server

    Hubbert, Simon; Morton, Tanya M

    2015-01-01

    This book is the first to be devoted to the theory and applications of spherical (radial) basis functions (SBFs), which is rapidly emerging as one of the most promising techniques for solving problems where approximations are needed on the surface of a sphere. The aim of the book is to provide enough theoretical and practical details for the reader to be able to implement the SBF methods to solve real world problems. The authors stress the close connection between the theory of SBFs and that of the more well-known family of radial basis functions (RBFs), which are well-established tools for solving approximation theory problems on more general domains. The unique solvability of the SBF interpolation method for data fitting problems is established and an in-depth investigation of its accuracy is provided. Two chapters are devoted to partial differential equations (PDEs). One deals with the practical implementation of an SBF-based solution to an elliptic PDE and another which describes an SBF approach for solvi...

  7. Radial Velocity Variability of Field Brown Dwarfs

    CERN Document Server

    Prato, L; Rice, E L; McLean, I S; Kirkpatrick, J D; Burgasser, A J; Kim, S S

    2015-01-01

    We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC infrared spectrograph at the W. M. Keck Observatory. With a radial velocity precision of ~2 km/s, we are sensitive to brown dwarf companions in orbits with periods of a few years or less given a mass ratio of 0.5 or greater. We do not detect any spectroscopic binary brown dwarfs in the sample. Given our target properties, and the frequency and cadence of observations, we use a Monte Carlo simulation to determine the detection probability of our sample. Even with a null detection result, our 1 sigma upper limit for very low mass binary frequency is 18%. Our targets included 7 known, wide brown dwarf binary systems. No significant radial velocity variability was measured in our multi-epoch observations of these systems, even for those pairs for which our data spanned a significant ...

  8. A radial transmission line material measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Warne, L.K.; Moyer, R.D.; Koontz, T.E.; Morris, M.E.

    1993-05-01

    A radial transmission line material measurement sample apparatus (sample holder, offset short standards, measurement software, and instrumentation) is described which has been proposed, analyzed, designed, constructed, and tested. The purpose of the apparatus is to obtain accurate surface impedance measurements of lossy, possibly anisotropic, samples at low and intermediate frequencies (vhf and low uhf). The samples typically take the form of sections of the material coatings on conducting objects. Such measurements thus provide the key input data for predictive numerical scattering codes. Prediction of the sample surface impedance from the coaxial input impedance measurement is carried out by two techniques. The first is an analytical model for the coaxial-to-radial transmission line junction. The second is an empirical determination of the bilinear transformation model of the junction by the measurement of three full standards. The standards take the form of three offset shorts (and an additional lossy Salisbury load), which have also been constructed. The accuracy achievable with the device appears to be near one percent.

  9. RADIAL VELOCITY ECLIPSE MAPPING OF EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Nikolov, Nikolay; Sainsbury-Martinez, Felix, E-mail: nikolay@astro.ex.ac.uk [Astrophysics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom)

    2015-07-20

    Planetary rotation rates and obliquities provide information regarding the history of planet formation, but have not yet been measured for evolved extrasolar planets. Here we investigate the theoretical and observational perspective of the Rossiter–McLaughlin effect during secondary eclipse (RMse) ingress and egress for transiting exoplanets. Near secondary eclipse, when the planet passes behind the parent star, the star sequentially obscures light from the approaching and receding parts of the rotating planetary surface. The temporal block of light emerging from the approaching (blueshifted) or receding (redshifted) parts of the planet causes a temporal distortion in the planet’s spectral line profiles resulting in an anomaly in the planet’s radial velocity curve. We demonstrate that the shape and the ratio of the ingress-to-egress radial velocity amplitudes depends on the planetary rotational rate, axial tilt, and impact factor (i.e., sky-projected planet spin–orbital alignment). In addition, line asymmetries originating from different layers in the atmosphere of the planet could provide information regarding zonal atmospheric winds and constraints on the hot spot shape for giant irradiated exoplanets. The effect is expected to be most-pronounced at near-infrared wavelengths, where the planet-to-star contrasts are large. We create synthetic near-infrared, high-dispersion spectroscopic data and demonstrate how the sky-projected spin axis orientation and equatorial velocity of the planet can be estimated. We conclude that the RMse effect could be a powerful method to measure exoplanet spins.

  10. A Minimal Solution to Radial Distortion Autocalibration.

    Science.gov (United States)

    Kukelova, Zuzana; Pajdla, Tomas

    2011-12-01

    Simultaneous estimation of radial distortion, epipolar geometry, and relative camera pose can be formulated as a minimal problem and solved from a minimal number of image points. Finding the solution to this problem leads to solving a system of algebraic equations. In this paper, we provide two different solutions to the problem of estimating radial distortion and epipolar geometry from eight point correspondences in two images. Unlike previous algorithms which were able to solve the problem from nine correspondences only, we enforce the determinant of the fundamental matrix be zero. This leads to a system of eight quadratic and one cubic equation in nine variables. We first simplify this system by eliminating six of these variables and then solve the system by two alternative techniques. The first one is based on the Gröbner basis method and the second one on the polynomial eigenvalue computation. We demonstrate that our solutions are efficient, robust, and practical by experiments on synthetic and real data.

  11. Radial stability of anisotropic strange quark stars

    Science.gov (United States)

    Arbañil, José D. V.; Malheiro, M.

    2016-11-01

    The influence of the anisotropy in the equilibrium and stability of strange stars is investigated through the numerical solution of the hydrostatic equilibrium equation and the radial oscillation equation, both modified from their original version to include this effect. The strange matter inside the quark stars is described by the MIT bag model equation of state. For the anisotropy two different kinds of local anisotropic σ = pt-pr are considered, where pt and pr are respectively the tangential and the radial pressure: one that is null at the star's surface defined by pr(R) = 0, and one that is nonnull at the surface, namely, σs = 0 and σs ≠ 0. In the case σs = 0, the maximum mass value and the zero frequency of oscillation are found at the same central energy density, indicating that the maximum mass marks the onset of the instability. For the case σs ≠ 0, we show that the maximum mass point and the zero frequency of oscillation coincide in the same central energy density value only in a sequence of equilibrium configurations with the same value of σs. Thus, the stability star regions are determined always by the condition dM/dρc > 0 only when the tangential pressure is maintained fixed at the star surface's pt(R). These results are also quite important to analyze the stability of other anisotropic compact objects such as neutron stars, boson stars and gravastars.

  12. Asymptotic Solutions of Serial Radial Fuel Shuffling

    Directory of Open Access Journals (Sweden)

    Xue-Nong Chen

    2015-12-01

    Full Text Available In this paper, the mechanism of traveling wave reactors (TWRs is investigated from the mathematical physics point of view, in which a stationary fission wave is formed by radial fuel drifting. A two dimensional cylindrically symmetric core is considered and the fuel is assumed to drift radially according to a continuous fuel shuffling scheme. A one-group diffusion equation with burn-up dependent macroscopic coefficients is set up. The burn-up dependent macroscopic coefficients were assumed to be known as functions of neutron fluence. By introducing the effective multiplication factor keff, a nonlinear eigenvalue problem is formulated. The 1-D stationary cylindrical coordinate problem can be solved successively by analytical and numerical integrations for associated eigenvalues keff. Two representative 1-D examples are shown for inward and outward fuel drifting motions, respectively. The inward fuel drifting has a higher keff than the outward one. The 2-D eigenvalue problem has to be solved by a more complicated method, namely a pseudo time stepping iteration scheme. Its 2-D asymptotic solutions are obtained together with certain eigenvalues keff for several fuel inward drifting speeds. Distributions of the neutron flux, the neutron fluence, the infinity multiplication factor kinf and the normalized power are presented for two different drifting speeds.

  13. Faster radial strain relaxation in InAs-GaAs core-shell heterowires

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, Karen L. [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Saveliev, Igor; Blumin, Marina; Ruda, Harry E. [Centre for Advanced Nanotechnology, University of Toronto, 170 College Street, Toronto, Ontario M5S 3E4 (Canada); Swadener, Greg [Mechanical Engineering and Design, Aston University, Aston Triangle, Birmingham B4 7ET (United Kingdom)

    2012-02-15

    The structure of wurtzite and zinc blende InAs-GaAs (001) core-shell nanowires grown by molecular beam epitaxy on GaAs (001) substrates has been investigated by transmission electron microscopy. Heterowires with InAs core radii exceeding 11 nm, strain relax through the generation of misfit dislocations, given a GaAs shell thickness greater than 2.5 nm. Strain relaxation is larger in radial directions than axial, particularly for shell thicknesses greater than 5.0 nm, consistent with molecular statics calculations that predict a large shear stress concentration at each interface corner.

  14. Severe atherosclerosis of the radial artery in a free radial forearm flap precluding its use.

    NARCIS (Netherlands)

    Bree, de R.; Quak, J.J.; Kummer, J.A.; Simsek, S.; Leemans, C.R.

    2004-01-01

    The free radial forearm flap is the most frequently used free flap for head and neck reconstructions. Survival of free flaps is dependent on adequate blood supply. A 69-year old woman was scheduled for excision of a T3N0M0 oropharyngeal carcinoma, neck dissections and reconstruction with a free vasc

  15. Atomic and molecular supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.

    1997-12-01

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  16. Endoscopic versus open radial artery harvest and mammario-radial versus aorto-radial grafting in patients undergoing coronary artery bypass surgery

    DEFF Research Database (Denmark)

    Carranza, Christian L; Ballegaard, Martin; Werner, Mads U

    2014-01-01

    , it is unknown whether the endoscopic technique results in fewer complications or a graft patency comparable to open harvest. When the radial artery has been harvested, there are two ways to use the radial artery as a graft. One way is sewing it onto the aorta and another is sewing it onto the mammary artery......) mammario-radial open surgery group; and (4) aorto-radial open surgery group.The hand function will be assessed by a questionnaire, a clinical examination, the change in cutaneous sensibility, and the measurement of both sensory and motor nerve conduction velocity at 3 months postoperatively. All...... the postoperative complications will be registered, and we will evaluate muscular function, scar appearance, vascular supply to the hand, and the graft patency including the patency of the central radial artery anastomosis. A patency evaluation by multi-slice computer tomography will be done at one year...

  17. Origin, Maturation and Astroglial Transformation of Secondary Radial Glial Cells in the Developing Dentate Gyrus

    Science.gov (United States)

    Brunne, Bianka; Zhao, Shanting; Derouiche, Amin; Herz, Joachim; May, Petra; Frotscher, Michael; Bock, Hans H.

    2010-01-01

    The dentate gyrus is a brain region where neurons are continuously born throughout life. In the adult, the role of its radial glia in neurogenesis has attracted much attention over the past years, however, little is known about the generation and differentiation of glial cells and their relationship to radial glia during the ontogenetic development of this brain structure. Here, we combine immunohistochemical phenotyping using antibodies against glial marker proteins with BrdU birthdating to characterize the development of the secondary radial glial scaffold in the dentate gyrus and its potential to differentiate into astrocytes. We demonstrate that the expression of BLBP, GLAST and GFAP characterizes immature differentiating cells confined to an astrocytic fate in the early postnatal dentate gyrus. Based on our studies we propose a model where immature astrocytes migrate radially through the granule cell layer to adopt their final positions in the molecular layer of the dentate gyrus. Time-lapse imaging of acute hippocampal slices from hGFAP-eGFP transgenic mice provide direct evidence for such a migration mode of differentiating astroglial cells in the developing dentate gyrus. PMID:20549747

  18. Increased radial glia quiescence, decreased reactivation upon injury and unaltered neuroblast behavior underlie decreased neurogenesis in the aging zebrafish telencephalon.

    Science.gov (United States)

    Edelmann, Kathrin; Glashauser, Lena; Sprungala, Susanne; Hesl, Birgit; Fritschle, Maike; Ninkovic, Jovica; Godinho, Leanne; Chapouton, Prisca

    2013-09-01

    The zebrafish has recently become a source of new data on the mechanisms of neural stem cell (NSC) maintenance and ongoing neurogenesis in adult brains. In this vertebrate, neurogenesis occurs at high levels in all ventricular regions of the brain, and brain injuries recover successfully, owing to the recruitment of radial glia, which function as NSCs. This new vertebrate model of adult neurogenesis is thus advancing our knowledge of the molecular cues in use for the activation of NSCs and fate of their progeny. Because the regenerative potential of somatic stem cells generally weakens with increasing age, it is important to assess the extent to which zebrafish NSC potential decreases or remains unaltered with age. We found that neurogenesis in the ventricular zone, in the olfactory bulb, and in a newly identified parenchymal zone of the telencephalon indeed declines as the fish ages and that oligodendrogenesis also declines. In the ventricular zone, the radial glial cell population remains largely unaltered morphologically but enters less frequently into the cell cycle and hence produces fewer neuroblasts. The neuroblasts themselves do not change their behavior with age and produce the same number of postmitotic neurons. Thus, decreased neurogenesis in the physiologically aging zebrafish brain is correlated with an increasing quiescence of radial glia. After injuries, radial glia in aged brains are reactivated, and the percentage of cell cycle entry is increased in the radial glia population. However, this reaction is far less pronounced than in younger animals, pointing to irreversible changes in aging zebrafish radial glia.

  19. New Approaches to Final Cooling

    CERN Document Server

    Neuffer, David

    2015-01-01

    A high-energy muon collider scenario requires a "final cooling" system that reduces transverse emittance by a factor of ~10 while allowing longitudinal emittance increase. The baseline approach has low-energy transverse cooling within high-field solenoids, with strong longitudinal heating. This approach and its recent simulation are discussed. Alternative approaches which more explicitly include emittance exchange are also presented. Round-to-flat beam transform, transverse slicing, and longitudinal bunch coalescence are possible components of the alternative approach. A more explicit understanding of solenoidal cooling beam dynamics is introduced.

  20. Cooling towers principles and practice

    CERN Document Server

    Hill, G B; Osborn, Peter D

    1990-01-01

    Cooling Towers: Principles and Practice, Third Edition, aims to provide the reader with a better understanding of the theory and practice, so that installations are correctly designed and operated. As with all branches of engineering, new technology calls for a level of technical knowledge which becomes progressively higher; this new edition seeks to ensure that the principles and practice of cooling towers are set against a background of up-to-date technology. The book is organized into three sections. Section A on cooling tower practice covers topics such as the design and operation of c

  1. CLIC inner detectors cooling simulations

    CERN Document Server

    Duarte Ramos, F.; Villarejo Bermudez, M.

    2014-01-01

    The strict requirements in terms of material budget for the inner region of the CLIC detector concepts require the use of a dry gas for the cooling of the respective sen- sors. This, in conjunction with the compactness of the inner volumes, poses several challenges for the design of a cooling system that is able to fulfil the required detec- tor specifications. This note introduces a detector cooling strategy using dry air as a coolant and shows the results of computational fluid dynamics simulations used to validate the proposed strategy.

  2. Passive low energy cooling of buildings

    CERN Document Server

    Givoni, Baruch

    1994-01-01

    A practical sourcebook for building designers, providing comprehensive discussion of the impact of basic architectural choices on cooling efficiency, including the layout and orientation of the structure, window size and shading, exterior color, and even the use of plantings around the site. All major varieties of passive cooling systems are presented, with extensive analysis of performance in different types of buildings and in different climates: ventilation; radiant cooling; evaporative cooling; soil cooling; and cooling of outdoor spaces.

  3. Compressor bleed cooling fluid feed system

    Science.gov (United States)

    Donahoo, Eric E; Ross, Christopher W

    2014-11-25

    A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.

  4. Porcine radial artery decellularization by high hydrostatic pressure.

    Science.gov (United States)

    Negishi, Jun; Funamoto, Seiichi; Kimura, Tsuyoshi; Nam, Kwangoo; Higami, Tetsuya; Kishida, Akio

    2015-11-01

    Many types of decellularized tissues have been studied and some have been commercially used in clinics. In this study, small-diameter vascular grafts were made using HHP to decellularize porcine radial arteries. One decellularization method, high hydrostatic pressure (HHP), has been used to prepare the decellularized porcine tissues. Low-temperature treatment was effective in preserving collagen and collagen structures in decellularized porcine carotid arteries. The collagen and elastin structures and mechanical properties of HHP-decellularized radial arteries were similar to those of untreated radial arteries. Xenogeneic transplantation (into rats) was performed using HHP-decellularized radial arteries and an untreated porcine radial artery. Two weeks after transplantation into rat carotid arteries, the HHP-decellularized radial arteries were patent and without thrombosis. In addition, the luminal surface of each decellularized artery was covered by recipient endothelial cells and the arterial medium was fully infiltrated with recipient cells.

  5. Microstructure and Property of Hypereutectic High Chromium Cast Iron Prepared by Slope Cooling Body-Centrifugal Casting Method

    Institute of Scientific and Technical Information of China (English)

    Zhifu HUANG; Jiandong XING; Anfeng ZHANG

    2006-01-01

    In this paper, the ring-type ingot of hypereutectic high Cr cast iron was obtained by slope cooling bodycentrifugal casting method (SC-CCM), and its microstructure and impact toughness were investigated, respectively. The results indicated that, first, the primary carbides in the microstructure are prominently finer than those in the hypereutectic high Cr cast iron prepared by conventional casting method. Second, in the ring-type ingot, the primary carbides near radial outer field are finer than those near radial inner field; furthermore, there is dividing field in the microstructure. Finally, the impact toughness values of the specimens impacted on the radial outer face and on the radial inner face are improved respectively about 36% and 138%more than that of the hypereutectic high Cr one prepared by conventional casting method.

  6. Radial expansion for spinning conformal blocks

    CERN Document Server

    Costa, Miguel; Hansen, Tobias; Penedones, João; Trevisani, Emilio

    2016-01-01

    This paper develops a method to compute any bosonic conformal block as a series expansion in the optimal radial coordinate introduced by Hogervorst and Rychkov. The method reduces to the known result when the external operators are all the same scalar operator, but it allows to compute conformal blocks for external operators with spin. Moreover, we explain how to write closed form recursion relations for the coefficients of the expansions. We study three examples of four point functions in detail: one vector and three scalars; two vectors and two scalars; two spin 2 tensors and two scalars. Finally, for the case of two external vectors, we also provide a more efficient way to generate the series expansion using the analytic structure of the blocks as a function of the scaling dimension of the exchanged operator.

  7. Ice formation around isothermal radial finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, K.A.R.; Henriquez, J.R.; Moura, L.F.M.; Ganzarolli, M.M. [UNICAMP-FEM-DETF, Campinas (Brazil)

    2000-04-01

    The present study presents a thermal numerical model for the solidification of Phase Change Material around a radially finned tube with a constant wall temperature. The model is based upon a pure conduction formulation and the enthalpy method. The finite difference approach and the alternating direction implicit scheme are used to discretize the system of equations and the associated boundary, initial and final conditions. Numerical experiments were realized to optimise the numerical code. Numerical simulations were performed to investigate the effects, of the number of fins, fin thickness, fin material, aspect ratio of the tube arrangement and the tube wall temperature. Graphical results were presented, discussed and equations relating the effect of each of the variables on the time for complete solidification are also presented. (author)

  8. Evolving spacetimes with purely radial tension

    Directory of Open Access Journals (Sweden)

    B. Nasre Esfahani

    2000-12-01

    Full Text Available   In this study time-dependent and spherically symmetric solutions of the Einstein field equations in an anisotropic background with a purely radial tension are presented. There exist three classes of solutions,1 An open spacetime with a wormhole at its center. 2 A conical spacetime. 3 A closed spacetime. These inhomogeneous solutions are reduced to FRW spacetimes in matter-dominated era, asymptotically. Therefore, they can be used to describe local inhomogeneities that are not considered in the standard model. For the wormhole solution. it is explicity shown that the considered matter is non-exotic, that is, it does not violate the energy conditions. Also, static solutions are studied. There is only one static solution,a conical spacetime. In this case, the matter satisfies the energy condition critically.

  9. Generalized multiscale radial basis function networks.

    Science.gov (United States)

    Billings, Stephen A; Wei, Hua-Liang; Balikhin, Michael A

    2007-12-01

    A novel modelling framework is proposed for constructing parsimonious and flexible multiscale radial basis function networks (RBF). Unlike a conventional standard single scale RBF network, where all the basis functions have a common kernel width, the new network structure adopts multiscale Gaussian functions as the bases, where each selected centre has multiple kernel widths, to provide more flexible representations with better generalization properties for general nonlinear dynamical systems. As a direct extension of the traditional single scale Gaussian networks, the new multiscale network is easy to implement and is quick to learn using standard learning algorithms. A k-means clustering algorithm and an improved orthogonal least squares (OLS) algorithm are used to determine the unknown parameters in the network model including the centres and widths of the basis functions, and the weights between the basis functions. It is demonstrated that the new network can lead to a parsimonious model with much better generalization property compared with the traditional single width RBF networks.

  10. Generalization performance of radial basis function networks.

    Science.gov (United States)

    Lei, Yunwen; Ding, Lixin; Zhang, Wensheng

    2015-03-01

    This paper studies the generalization performance of radial basis function (RBF) networks using local Rademacher complexities. We propose a general result on controlling local Rademacher complexities with the L1 -metric capacity. We then apply this result to estimate the RBF networks' complexities, based on which a novel estimation error bound is obtained. An effective approximation error bound is also derived by carefully investigating the Hölder continuity of the lp loss function's derivative. Furthermore, it is demonstrated that the RBF network minimizing an appropriately constructed structural risk admits a significantly better learning rate when compared with the existing results. An empirical study is also performed to justify the application of our structural risk in model selection.

  11. Radial velocity monitoring of Kepler heartbeat stars

    CERN Document Server

    Shporer, Avi; Isaacson, Howard; Hambleton, Kelly; Thompson, Susan E; Prsa, Andrej; Kurtz, Donald W; Howard, Andrew W; O'Leary, Ryan M

    2016-01-01

    Heartbeat stars (HB stars) are a class of eccentric binary stars with close periastron passages. The characteristic photometric HB signal evident in their light curves is produced by a combination of tidal distortion, heating, and Doppler boosting near orbital periastron. Many HB stars continue to oscillate after periastron and along the entire orbit, indicative of the tidal excitation of oscillation modes within one or both stars. These systems are among the most eccentric binaries known, and they constitute astrophysical laboratories for the study of tidal effects. We have undertaken a radial velocity (RV) monitoring campaign of Kepler HB stars in order to measure their orbits. We present our first results here, including a sample of 21 Kepler HB systems, where for 19 of them we obtained the Keplerian orbit and for 3 other systems we did not detect a statistically significant RV variability. Results presented here are based on 218 spectra obtained with the Keck/HIRES spectrograph during the 2015 Kepler obse...

  12. Precise radial velocities in the near infrared

    Science.gov (United States)

    Redman, Stephen L.

    Since the first detection of a planet outside our Solar System byWolszczan & Frail (1992), over 500 exoplanets have been found to date2, none of which resemble the Earth. Most of these planets were discovered by measuring the radial velocity (hereafter, RV) of the host star, which wobbles under the gravitational influence of any existing planetary companions. However, this method has yet to achieve the sub-m/s precision necessary to detect an Earth-mass planet in the Habitable Zone (the region around a star that can support liquid water; hereafter, HZ) (Kasting et al. 1993) around a Solar-type star. Even though Kepler (Borucki et al. 2010) has announced several Earth-sized HZ candidates, these targets will be exceptionally difficult to confirm with current astrophysical spectrographs (Borucki et al. 2011). The fastest way to discover and confirm potentiallyhabitable Earth-mass planets is to observe stars with lower masses - in particular, late M dwarfs. While M dwarfs are readily abundant, comprising some 70% of the local stellar population, their low optical luminosity presents a formidable challenge to current optical RV instruments. By observing in the near-infrared (hereafter, NIR), where the flux from M dwarfs peaks, we can potentially reach low RV precisions with significantly less telescope time than would be required by a comparable optical instrument. However, NIR precision RV measurements are a relatively new idea and replete with challenges: IR arrays, unlike CCDs, are sensitive to the thermal background; modal noise is a bigger issue in the NIR than in the optical; and the NIR currently lacks the calibration sources like the very successful thorium-argon (hereafter, ThAr) hollow-cathode lamp and Iodine gas cell of the optical. The PSU Pathfinder (hereafter, Pathfinder) was designed to explore these technical issues with the intention of mitigating these problems for future NIR high-resolution spectrographs, such as the Habitable-Zone Planet Finder (HZPF

  13. Amorphous metals for radial airgap electric machines

    Energy Technology Data Exchange (ETDEWEB)

    Lu Ning; Kokernak, J.M. [Rensselaer Polytechnic Institute, Dept. of Electric Poer Engineering, Troy, NY (United States)

    2000-08-01

    Amorphous steel teas been in use for some time in the transformer industry. The difficulty associated with handling such a hard material paired with the extremely thin nature of the casting has prevented amorphous steel from being seriously considered for radial airgap electric motors. In light of recent advances in manufacturing and handling of the amorphous materials, this paper presents an investigation into the performance advantages of an amorphous brushless dc motor. A two-dimensional, time-stepped, finite element model is used to analyze the electromagnetic field and motor performance for an amorphous brushless dc (BLDC) motor and a M-l9 BLDC motor. Each is modeled with identical structure geometries. Magnetic core losses are also estimated for the two motors operating over a frequency range of 50 to 200 Hz. (orig.)

  14. Macrostrain measurement using radial collimators at LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Bourke, M.A.M.; Roberts, J.A.; Davis, D.

    1996-06-01

    A series of `short` radial collimators have been implemented in the 90{degrees} scattering geometries on the neutron powder diffractometer at Los Alamos. The capability to perform macrostrain measurements has been improved by the commensurate ability to rapidly select a sampling volume appropriate to the specimen. The compact design of the collimators was dictated by the need to fit them in a cylindrical vacuum chamber as well as providing space in which to manipulate a specimen in three dimensions. Collimators of different vane lengths were fabricated to give 4 different resolutions for which 2/3 of the diffracted intensity comes form distances of 0.75, 1. 25, 2.5, and 4.0 mm along the incident beam. Qualifying scans and a demonstration of a cracked ring, containing a steep stress gradient, are included.

  15. Cooling Technology for Electronic Computers

    Science.gov (United States)

    Nakayama, Wataru

    The rapid growth of data processing speed in computers has been sustained by the advances in cooling technology. This article first presents a review of the published data of heat loads in recent Japanese large-scale computers. The survey indicates that, since around 1980, the high-level integration of microelectronic circuits has brought about almost four fold increase in the power dissipation from logic chips. The integration also has invited the evolutions of multichip modules and new schemes of electronic interconnections. Forced convection air-cooling and liquid cooling coupled with thermal connectors are discussed with reference to the designs employed in actual computers. More advanced cooling schemes are also discussed. Finally, the importance of thermal environmental control of computer rooms is emphasized.

  16. Cooled Ceramic Turbine Vane Project

    Data.gov (United States)

    National Aeronautics and Space Administration — N&R Engineering will investigate the feasibility of cooled ceramics, such as ceramic matrix composite (CMC) turbine blade concepts that can decrease specific...

  17. Surface-induced evaporative cooling

    Institute of Scientific and Technical Information of China (English)

    Ke Min; Yan Bo; Cheng Feng; Wang Yu-Zhu

    2009-01-01

    The effects of surface-induced evaporative cooling on an atom chip are investigated. The evolutions of temperature, number and phase-space density of the atom cloud are measured when the atom cloud is brought close to the surface. Rapid decrease of the temperature and number of the atoms is found when the atom-surface distance is < 100 μm. A gain of about a factor of five on the phase-space density is obtained. It is found that the efficiency of the surface-induced evaporative cooling depends on the atom-surface distance and the shape of the evaporative trap. When the atoms are moved very close to the surface, severe heating is observed, which dominates when the holding time is > 8 ms. It is important that the surface-induced evaporative cooling offers novel possibilities for the realization of a continuous condensation, where a spatially varying evaporative cooling is required.

  18. Radial-Electric-Field Piezoelectric Diaphragm Pumps

    Science.gov (United States)

    Bryant, Robert G.; Working, Dennis C.; Mossi, Karla; Castro, Nicholas D.; Mane, Pooma

    2009-01-01

    In a recently invented class of piezoelectric diaphragm pumps, the electrode patterns on the piezoelectric diaphragms are configured so that the electric fields in the diaphragms have symmetrical radial (along-the-surface) components in addition to through-the-thickness components. Previously, it was accepted in the piezoelectric-transducer art that in order to produce the out-of-plane bending displacement of a diaphragm needed for pumping, one must make the electric field asymmetrical through the thickness, typically by means of electrodes placed on only one side of the piezoelectric material. In the present invention, electrodes are placed on both sides and patterned so as to produce substantial radial as well as through-the-thickness components. Moreover, unlike in the prior art, the electric field can be symmetrical through the thickness. Tests have shown in a given diaphragm that an electrode configuration according to this invention produces more displacement than does a conventional one-sided electrode pattern. The invention admits of numerous variations characterized by various degrees of complexity. Figure 1 is a simplified depiction of a basic version. As in other piezoelectric diaphragm pumps of similar basic design, the prime mover is a piezoelectric diaphragm. Application of a suitable voltage to the electrodes on the diaphragm causes it to undergo out-of-plane bending. The bending displacement pushes a fluid out of, or pulls the fluid into, a chamber bounded partly by the diaphragm. Also as in other diaphragm pumps in general, check valves ensure that the fluid flows only in through one port and only out through another port.

  19. Radial Shock Wave Devices Generate Cavitation.

    Directory of Open Access Journals (Sweden)

    Nikolaus B M Császár

    Full Text Available Conflicting reports in the literature have raised the question whether radial extracorporeal shock wave therapy (rESWT devices and vibrating massage devices have similar energy signatures and, hence, cause similar bioeffects in treated tissues.We used laser fiber optic probe hydrophone (FOPH measurements, high-speed imaging and x-ray film analysis to compare fundamental elements of the energy signatures of two rESWT devices (Swiss DolorClast; Electro Medical Systems, Nyon, Switzerland; D-Actor 200; Storz Medical, Tägerwillen, Switzerland and a vibrating massage device (Vibracare; G5/General Physiotherapy, Inc., Earth City, MO, USA. To assert potential bioeffects of these treatment modalities we investigated the influence of rESWT and vibrating massage devices on locomotion ability of Caenorhabditis elegans (C. elegans worms.FOPH measurements demonstrated that both rESWT devices generated acoustic waves with comparable pressure and energy flux density. Furthermore, both rESWT devices generated cavitation as evidenced by high-speed imaging and caused mechanical damage on the surface of x-ray film. The vibrating massage device did not show any of these characteristics. Moreover, locomotion ability of C. elegans was statistically significantly impaired after exposure to radial extracorporeal shock waves but was unaffected after exposure of worms to the vibrating massage device.The results of the present study indicate that both energy signature and bioeffects of rESWT devices are fundamentally different from those of vibrating massage devices.Prior ESWT studies have shown that tissues treated with sufficient quantities of acoustic sound waves undergo cavitation build-up, mechanotransduction, and ultimately, a biological alteration that "kick-starts" the healing response. Due to their different treatment indications and contra-indications rESWT devices cannot be equated to vibrating massage devices and should be used with due caution in clinical

  20. Radial Matrix Elements of Hydrogen Atom and the Correspondence Principle

    Indian Academy of Sciences (India)

    T. N. Chakrabarty

    2004-03-01

    Radial dipole matrix elements having astrophysical importance have been computed for highly excited states of hydrogen atom. Computation is based on Heisenberg’s form of correspondence principle for Coulomb potential. Particular attention has been paid to the choice of classical analogue (c) of principal quantum number (). The computed radial matrix elements are in good agreement with quantum mechanical results. Further, radial matrix elements for few transitions involving high neighboring states of hydrogen atom are presented.

  1. Radial velocity planet detection biases at the stellar rotational period

    OpenAIRE

    2016-01-01

    Future generations of precise radial velocity (RV) surveys aim to achieve sensitivity sufficient to detect Earth mass planets orbiting in their stars' habitable zones. A major obstacle to this goal is astrophysical radial velocity noise caused by active areas moving across the stellar limb as a star rotates. In this paper, we quantify how stellar activity impacts exoplanet detection with radial velocities as a function of orbital and stellar rotational periods. We perform data-driven simulati...

  2. A New Filtering Algorithm Utilizing Radial Velocity Measurement

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-feng; DU Zi-cheng; PAN Quan

    2005-01-01

    Pulse Doppler radar measurements consist of range, azimuth, elevation and radial velocity. Most of the radar tracking algorithms in engineering only utilize position measurement. The extended Kalman filter with radial velocity measureneut is presented, then a new filtering algorithm utilizing radial velocity measurement is proposed to improve tracking results and the theoretical analysis is also given. Simulation results of the new algorithm, converted measurement Kalman filter, extended Kalman filter are compared. The effectiveness of the new algorithm is verified by simulation results.

  3. Turbine Blade Cooling System Optimization

    OpenAIRE

    GIRARDEAU, Julian; PAILHES, Jérôme; SEBASTIAN, Patrick; PARDO, Frédéric; Nadeau, Jean-Pierre

    2013-01-01

    The authors wish to thank turbine designers from TURBOMECA SAFRAN Group.; International audience; Designing high performance cooling systems suitable for preserving the service lifetime of nozzle guide vanes of turboshaft engines leads to significant aerodynamic losses. These losses jeopardize the performance of the whole engine. In the same time, a low efficiency cooling system may affect the costs of maintenance repair and overhaul of the engine as component life decreases. Consequently, de...

  4. DETERMINATION OF RADIATOR COOLING SURFACE

    Directory of Open Access Journals (Sweden)

    A. I. Yakubovich

    2009-01-01

    Full Text Available The paper proposes a methodology for calculation of a radiator cooling surface with due account of heat transfer non-uniformity on depth of its core. Calculation of radiator cooling surfaces of «Belarus-1221» and «Belarus-3022» tractors has been carried out in the paper. The paper also advances standard size series of radiators for powerful «Belarus» tractor type.

  5. Quantum limit of photothermal cooling

    CERN Document Server

    De Liberato, Simone; Nori, Franco

    2010-01-01

    We study the problem of cooling a mechanical oscillator using the photothermal (bolometric) force. Contrary to previous attempts to model this system, we take into account the noise effects due to the granular nature of photon absorption. This allows us to tackle the cooling problem down to the noise dominated regime and to find reasonable estimates for the lowest achievable phonon occupation in the cantilever.

  6. Cooling Shelf For Electronic Equipment

    Science.gov (United States)

    Tanzer, Herbert J.

    1989-01-01

    Heat-pipe action cools and maintains electronics at nearly constant temperature. System designed to control temperatures of spacecraft shelves or baseplates by combining honeycomb sandwich panel with reservoir of noncondensable gas and processing resulting device as variable-conductance heat pipe. Device provides flat surface for mounting heat-dissipating electronics that is effectively cooled and maintained at nearly constant temperature. Potentially useful in freeze drying, refrigeration, and air conditioning.

  7. Energy Efficient Electronics Cooling Project

    Energy Technology Data Exchange (ETDEWEB)

    Steve O' Shaughnessey; Tim Louvar; Mike Trumbower; Jessica Hunnicutt; Neil Myers

    2012-02-17

    Parker Precision Cooling Business Unit was awarded a Department of Energy grant (DE-EE0000412) to support the DOE-ITP goal of reducing industrial energy intensity and GHG emissions. The project proposed by Precision Cooling was to accelerate the development of a cooling technology for high heat generating electronics components. These components are specifically related to power electronics found in power drives focused on the inverter, converter and transformer modules. The proposed cooling system was expected to simultaneously remove heat from all three of the major modules listed above, while remaining dielectric under all operating conditions. Development of the cooling system to meet specific customer's requirements and constraints not only required a robust system design, but also new components to support long system functionality. Components requiring further development and testing during this project included pumps, fluid couplings, cold plates and condensers. All four of these major categories of components are required in every Precision Cooling system. Not only was design a key area of focus, but the process for manufacturing these components had to be determined and proven through the system development.

  8. Unusual presentation of a radial neck fracture in a child

    Directory of Open Access Journals (Sweden)

    Murali Poduval

    2013-01-01

    Full Text Available Fracture of the radial neck are uncommon injuries. In children, they may present as radial neck fractures, a components of forearm fracture dislocations, or as isolated fracture dislocations. Here, we present an unusual and previously undescribed variant of radial neck fracture with dislocation of the radial head to the medial side and ulnar nerve injury. The fracture dislocation was openly reduced and fixed with a small fragment plate. The fracture healed with some loss of rotational movements. At short followup of 6 months patient had useful elbow function but ulnar nerve did not recover.

  9. An improved equivalent circuit model of radial mode piezoelectric transformer.

    Science.gov (United States)

    Huang, Yihua; Huang, Wei

    2011-05-01

    In this paper, both the equivalent circuit models of the radial mode and the coupled thickness vibration mode of the radial mode piezoelectric transformer are deduced, and then with the Y-parameter matrix method and the dual-port network theory, an improved equivalent circuit model for the multilayer radial mode piezoelectric transformer is established. A radial mode transformer sample is tested to verify the equivalent circuit model. The experimental results show that the model proposed in this paper is more precise than the typical model.

  10. Design Concepts for Cooled Ceramic Composite Turbine Vane

    Science.gov (United States)

    Boyle, Robert J.; Parikh, Ankur H.; Nagpal, VInod K.

    2015-01-01

    The objective of this work was to develop design concepts for a cooled ceramic vane to be used in the first stage of the High Pressure Turbine(HPT). To insure that the design concepts were relevant to the gas turbine industry needs, Honeywell International Inc. was subcontracted to provide technical guidance for this work. The work performed under this contract can be divided into three broad categories. The first was an analysis of the cycle benefits arising from the higher temperature capability of Ceramic Matrix Composite(CMC) compared with conventional metallic vane materials. The second category was a series of structural analyses for variations in the internal configuration of first stage vane for the High Pressure Turbine(HPT) of a CF6 class commercial airline engine. The third category was analysis for a radial cooled turbine vanes for use in turboshaft engine applications. The size, shape and internal configuration of the turboshaft engine vanes were selected to investigate a cooling concept appropriate to small CMC vanes.

  11. Cryogenic cooling system for HTS cable

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shigeru [Taiyo Nippon Sanso, Tsukuba (Japan)

    2017-06-15

    Recently, Research and development activity of HTS (High Temperature Superconducting) power application is very progressive worldwide. Especially, HTS cable system and HTSFCL (HTS Fault current limiter) system are proceeding to practical stages. In such system and equipment, cryogenic cooling system, which makes HTS equipment cooled lower than critical temperature, is one of crucial components. In this article, cryogenic cooling system for HTS application, mainly cable, is reviewed. Cryogenic cooling system can be categorized into conduction cooling system and immersion cooling system. In practical HTS power application area, immersion cooling system with sub-cooled liquid nitrogen is preferred. The immersion cooling system is besides grouped into open cycle system and closed cycle system. Turbo-Brayton refrigerator is a key component for closed cycle system. Those two cooling systems are focused in this article. And, each design and component of the cooling system is explained.

  12. Microtextured Surfaces for Turbine Blade Impingement Cooling

    Science.gov (United States)

    Fryer, Jack

    2014-01-01

    Gas turbine engine technology is constantly challenged to operate at higher combustor outlet temperatures. In a modern gas turbine engine, these temperatures can exceed the blade and disk material limits by 600 F or more, necessitating both internal and film cooling schemes in addition to the use of thermal barrier coatings. Internal convective cooling is inadequate in many blade locations, and both internal and film cooling approaches can lead to significant performance penalties in the engine. Micro Cooling Concepts, Inc., has developed a turbine blade cooling concept that provides enhanced internal impingement cooling effectiveness via the use of microstructured impingement surfaces. These surfaces significantly increase the cooling capability of the impinging flow, as compared to a conventional untextured surface. This approach can be combined with microchannel cooling and external film cooling to tailor the cooling capability per the external heating profile. The cooling system then can be optimized to minimize impact on engine performance.

  13. Radial structure of the constricted positive column: Modeling and experiment

    Science.gov (United States)

    Golubovskii, Yu.; Kalanov, D.; Maiorov, V.

    2017-08-01

    We present a detailed self-consistent model of a positive column in argon glow discharge at moderate pressures and currents. This model describes the discharge transition between diffuse and constricted states. The model includes an extensive set of plasma chemical reactions and equation for inhomogeneous gas heating. The nonequilibrium behavior of an electron distribution function is also considered. One of the main features of the model is an accurate treatment of radiation trapping by solving the Holstein-Biberman equation directly. Influence of the radiation trapping on macroscopic parameters of the constricted positive column is studied. We propose a method for solving a boundary-value problem, including particle and energy balance equations for electrons, ground state atoms, atomic and molecular ions, and excited species. Unlike traditional solution approaches for similar systems, the method provides continuous Z- and S-shaped characteristics of discharge parameters, describing hysteresis in transition between diffuse and constricted discharge regimes. Performed experiments include measurements of volt-ampere characteristics and spectroscopic study of radial density profiles of excited atoms by measuring line emission and absorption, and electrons by measuring bremsstrahlung intensity. The role of resonance radiation trapping in spatial redistribution of 1 s and 2 p states of argon is demonstrated. Results of modeling are compared to the experimental data.

  14. Floor cooling and air-cooling, the effects on thermal comfort or different cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Sijpheer, N.C.; Bakker, E.J.; Ligthart, F.A.T.M.; Opstelten, I.J. [ECN Energie in de Gebouwde Omgeving en Netten, Petten (Netherlands)

    2007-09-15

    One of the research areas of the Energy research Centre of the Netherlands (ECN) concerns the built environment. Several facilities to conduct research activities are at ECN's disposal. One of these facilities, are five research dwellings located on the premises of ECN. Measured data from these facilities together with weather data and computer models are used to evaluate innovative energy concepts and components in energy systems. Experiments with different cooling systems in ECN's research dwellings are executed to evaluate their effective influence on both energy use and thermal comfort. Influence of inhabitants' behaviour is taken into account in these experiments. The thermal comfort is indicated by the Predicted Mean Vote (PMV) as defined by P.O. Fanger. For this paper, the results of measurements with a floor cooling and air cooling system are assessed. Effects on the PMV measured during experiments with the two different cooling systems will be presented.

  15. Astrometric radial velocities. I. Non-spectroscopic methods for measuring stellar radial velocity

    OpenAIRE

    1999-01-01

    High-accuracy astrometry permits the determination of not only stellar tangential motion, but also the component along the line-of-sight. Such non-spectroscopic (i.e. astrometric) radial velocities are independent of stellar atmospheric dynamics, spectral complexity and variability, as well as of gravitational redshift. Three methods are analysed: (1) changing annual parallax, (2) changing proper motion and (3) changing angular extent of a moving group of stars. All three have significant pot...

  16. Radiation Dose Reduction during Radial Cardiac Catheterization: Evaluation of a Dedicated Radial Angiography Absorption Shielding Drape.

    Science.gov (United States)

    Ertel, Andrew; Nadelson, Jeffrey; Shroff, Adhir R; Sweis, Ranya; Ferrera, Dean; Vidovich, Mladen I

    2012-01-01

    Objectives. Radiation scatter protection shield drapes have been designed with the goal of decreasing radiation dose to the operators during transfemoral catheterization. We sought to investigate the impact on operator radiation exposure of various shielding drapes specifically designed for the radial approach. Background. Radial access for cardiac catheterization has increased due to improved patient comfort and decreased bleeding complications. There are concerns for increased radiation exposure to patients and operators. Methods. Radiation doses to a simulated operator were measured with a RadCal Dosimeter in the cardiac catheterization laboratory. The mock patient was a 97.5 kg fission product phantom. Three lead-free drape designs were studied. The drapes were placed just proximal to the right wrist and extended medially to phantom's trunk. Simulated diagnostic coronary angiography included 6 minutes of fluoroscopy time and 32 seconds of cineangiography time at 4 standard angulated views (8 s each), both 15 frames/s. ANOVA with Bonferroni correction was used for statistical analysis. Results. All drape designs led to substantial reductions in operator radiation exposure compared to control (P radiation exposure (72%) was with the L-shaped design. Conclusions. Dedicated radial shielding drapes decrease radiation exposure to the operator by up to 72% during simulated cardiac catheterization.

  17. Fuel radial design using Path Relinking; Diseno radial de combustible usando Path Relinking

    Energy Technology Data Exchange (ETDEWEB)

    Campos S, Y. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The present work shows the obtained results when implementing the combinatory optimization technique well-known as Path Re linking (Re-linkage of Trajectories), to the problem of the radial design of nuclear fuel assemblies, for boiling water reactors (BWR Boiling Water Reactor by its initials in English), this type of reactors is those that are used in the Laguna Verde Nucleo electric Central, Veracruz. As in any other electric power generation plant of that make use of some fuel to produce heat and that it needs each certain time (from 12 to 14 months) to make a supply of the same one, because this it wears away or it burns, in the nucleolectric plants to this activity is denominated fuel reload. In this reload different activities intervene, among those which its highlight the radial and axial designs of fuel assemblies, the patterns of control rods and the multi cycles study, each one of these stages with their own complexity. This work was limited to study in independent form the radial design, without considering the other activities. These phases are basic for the fuel reload design and of reactor operation strategies. (Author)

  18. Neurological Study of Radial Nerve Conduction During Endoscopic Radial Artery Harvesting:An Intra‐Operative Evaluation

    Directory of Open Access Journals (Sweden)

    Gianluigi Bisleri

    2014-08-01

    Full Text Available Endoscopic radial artery harvesting (ERAH is a feasible and attractive minimally invasive approach for conduit procurement, however there have been concerns about a potential neurological damage occurring at the harvest limb site secondary to injury of the radial nerve during endoscopic harvesting. We present a case of ERAH in which we evaluated intraoperatively the characteristics of radial nerve conduction by means of electroneuromyography (ENM during harvesting. No pathological changes of nerve conduction were detected at the harvest limb site during surgery and postoperatively, thereby supporting the benefits of the endoscopic approach in terms of neurological outcomes following radial artery procurements with a less invasive approach.

  19. Radial distribution and strong lensing statistics of satellite galaxies and substructure using high resolution LCDM hydrodynamical simulations

    CERN Document Server

    Maccio, A V; Stadel, J; Diemand, J; Maccio', Andrea V.; Moore, Ben; Stadel, Joachim; Diemand, Juerg

    2006-01-01

    We analyse the number density and radial distribution of substructures and satellite galaxies using cosmological simulations that follow the gas dynamics of a baryonic component, including shock heating, radiative cooling and star formation within the hierarchical concordance LCDM model. We find that the dissipation of the baryons greatly enhances the survival of subhaloes, expecially in the galaxy core, resulting in a radial distribution of satellite galaxies that closely follows the overall mass distribution. Hydrodynamical simulations are necessary to resolve the adiabatic contraction and dense cores of galaxies, resulting in a total number of satellites a factor of two larger than found in pure dark matter simulation. Convergence tests show that the cored distribution found by previous authors was due to physical overmerging of dark matter only structures. We proceed to use a ray-shooting technique in order to study the impact of these additional substructures on the number of violations of the cusp caust...

  20. Bunched Beam Cooling in the Fermilab Recycler

    CERN Document Server

    Neuffer, David V; Burov, Alexey; Nagaitsev, Sergei

    2005-01-01

    Stochastic cooling with bunched beam in a linear bucket has been obtained and implemented operationally in the fermilab recycler. In this implementation the particle bunch length is much greater than the cooling system wavelengths. The simultaneous longitudinal bunching enables cooling to much smaller longitudinal emittances than the coasting beam or barrier bucket system. Characteristics and limitations of bunched beam stochastic cooling are discussed.

  1. A new Newton's law of cooling?

    Science.gov (United States)

    Kleiber, M

    1972-12-22

    Several physiologists confuse Fourier's law of animal heat flow with Newton's law of cooling. A critique of this error in 1932 remained ineffective. In 1969 Molnar tested Newton's cooling law. In 1971 Strunk found Newtonian cooling unrealistic for animals. Unfortunately, he called the Fourier formulation of animal heat flow, requiring post-Newtonian observations, a "contemporary Newtonian law of cooling."

  2. 14 CFR 25.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 25.1043 Section 25.1043... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Cooling § 25.1043 Cooling tests. (a) General. Compliance... during the cooling tests must be the minimum grade approved for the engines, and the mixture...

  3. 14 CFR 27.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 27.1043 Section 27.1043... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Cooling § 27.1043 Cooling tests. (a) General. For the tests... during the cooling tests must be of the minimum grade approved for the engines, and the mixture...

  4. 14 CFR 29.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 29.1043 Section 29.1043... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Cooling § 29.1043 Cooling tests. (a) General. For the... (a)(1) of this section may exceed established limits. (3) The fuel used during the cooling tests...

  5. 14 CFR 29.908 - Cooling fans.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling fans. 29.908 Section 29.908... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant General § 29.908 Cooling fans. For cooling fans that are a part of a powerplant installation the following apply: (a) Category A. For cooling fans...

  6. 14 CFR 23.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 23.1043 Section 23.1043... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Cooling § 23.1043 Cooling... established limits. (3) The fuel used during the cooling tests must be of the minimum grade approved for...

  7. Impingement jet cooling in gas turbines

    CERN Document Server

    Amano, R S

    2014-01-01

    Due to the requirement for enhanced cooling technologies on modern gas turbine engines, advanced research and development has had to take place in field of thermal engineering. Impingement jet cooling is one of the most effective in terms of cooling, manufacturability and cost. This is the first to book to focus on impingement cooling alone.

  8. New cooling regulation technology of secondary cooling station in DCS

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Yan, Jun-wei; Zhu, Dong-sheng; Liu, Fei-long; Lei, Jun-xi [The Key Lab of Enhanced Heat Transfer and Energy Conservation of Ministry of Education, School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510641 (China); Liang, Lie-quan [The Key Lab of E-Commerce Market Application Technology of Guangdong Province, Guangdong University of Business Studies, Guangzhou 510320 (China)

    2008-07-01

    In this paper, a kind of new control technology of secondary cooling station (constant flow rate/variable temperature difference) in district cooling system (DCS) is proposed in view of serial consequences including low efficiency and high operating cost caused by low temperature of supply water in DCS. This technology has been applied in DCS of Guangzhou University City. The result has already indicated that such technology can increase the supply and return temperatures of buildings, return water temperature of primary side in the plate heat exchanger unit, moreover, the efficiency of both the chiller and the whole system are improved significantly. (author)

  9. Cooling Efficiency of Laminar Cooling System for Plate Mill

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dian-hua; WANG Bing-xing; ZHOU Na; YU Ming; WANG Jun

    2008-01-01

    Heat transfer was researched from a perspective of the industry application.On the basis of the first law of thermodynamics,the cooling efficiency was deduced from the change of enthalpy inside hot plate.The relationship between the cooling efficiency and its influencing parameters was regressed from plenty of data collected from the worksite and discussed in detail.The temperature profiles resulting from the online model and the model modified by regressed formulas were presented and compared.The results indicated that the control accuracy of the modified model was increased obviously.

  10. Outcome of Radial Head Arthroplasty in Comminuted Radial Head Fractures: Short and Midterm Results

    Directory of Open Access Journals (Sweden)

    Moghaddam

    2016-02-01

    Full Text Available Background Comminuted radial head fractures are often associated with secondary injuries and elbow instability. Objectives The aim of this retrospective study was to evaluate how well the modular metallic radial head implant EVOLVE® prosthesis restores functional range of motion (ROM and stability of the elbow in acute care. Patients and Methods Eighty-five patients with comminuted radial head fractures and associated injuries received treatment with an EVOLVE® prosthesis between May 2001 and November 2009. Seventy-five patients were available for follow-up. On average, patients were followed for 41.5 months (33.0: 4.0 - 93.0. Outcome assessment was done on the basis of pain, ROM, strength, radiographic findings, and functional rating scores such as Broberg and Morrey, the Mayo elbow performance index (MEPI, and disabilities of the arm, shoulder and hand (DASH. Our study is currently the largest analysis of clinical outcome of a modular radial head replacement in the literature. Results Overall, there were 2 (2.7% Mason II fractures, 21 (28% Mason III fractures, and 52 (69.3% Mason IV fractures. Arbeitsgemeinschaft fur osteosynthesefragen (AO classification was also determined. Of the 85 patients in our study, 75 were available for follow-up. Follow-up averaged 41.5 months (range, 4 - 93 months. Average scores for the cohort were as follows: Morrey, 85.7 (median 90.2; range 44.4 - 100; MEPI, 83.3 (85.0; 40.0 - 100; and DASH 26.1 points (22.5; 0.0 - 75.8. Mean flexion/extension in the affected joint was 125.7°/16.5°/0° in comparison to the noninjured side 138.5°/0°/1.2°. Mean pronation/supination was 70.5°/0°/67.1° in comparison to the noninjured side 83.6°/0°/84.3°. Handgrip strength of the injured compared to the non-injured arm was 78.8%. The following complications were also documented: 58 patients had periprosthetic radioluceny shown to be neither clinically significant nor relevant according to evaluated scores; 26 patients

  11. Phenotypic evolution from genetic polymorphisms in a radial network architecture

    Directory of Open Access Journals (Sweden)

    Siegel Paul B

    2007-11-01

    Full Text Available Abstract Background The genetic architecture of a quantitative trait influences the phenotypic response to natural or artificial selection. One of the main objectives of genetic mapping studies is to identify the genetic factors underlying complex traits and understand how they contribute to phenotypic expression. Presently, we are good at identifying and locating individual loci with large effects, but there is a void in describing more complex genetic architectures. Although large networks of connected genes have been reported, there is an almost complete lack of information on how polymorphisms in these networks contribute to phenotypic variation and change. To date, most of our understanding comes from theoretical, model-based studies, and it remains difficult to assess how realistic their conclusions are as they lack empirical support. Results A previous study provided evidence that nearly half of the difference in eight-week body weight between two divergently selected lines of chickens was a result of four loci organized in a 'radial' network (one central locus interacting with three 'radial' loci that, in turn, only interacted with the central locus. Here, we study the relationship between phenotypic change and genetic polymorphism in this empirically detected network. We use a model-free approach to study, through individual-based simulations, the dynamic properties of this polymorphic and epistatic genetic architecture. The study provides new insights to how epistasis can modify the selection response, buffer and reveal effects of major loci leading to a progressive release of genetic variation. We also illustrate the difficulty of predicting genetic architecture from observed selection response, and discuss mechanisms that might lead to misleading conclusions on underlying genetic architectures from quantitative trait locus (QTL experiments in selected populations. Conclusion Considering both molecular (QTL and phenotypic (selection

  12. Personal cooling apparatus and method

    Energy Technology Data Exchange (ETDEWEB)

    Siman-Tov, Moshe (Knoxville, TN); Crabtree, Jerry Allen (Knoxville, TN)

    2001-01-01

    A portable lightweight cooling apparatus for cooling a human body is disclosed, having a channeled sheet which absorbs sweat and/or evaporative liquid, a layer of highly conductive fibers adjacent the channeled sheet; and, an air-moving device for moving air through the channeled sheet, wherein the layer of fibers redistributes heat uniformly across the object being cooled, while the air moving within the channeled sheet evaporates sweat and/or other evaporative liquid, absorbs evaporated moisture and the uniformly distributed heat generated by the human body, and discharges them into the environment. Also disclosed is a method for removing heat generated by the human body, comprising the steps of providing a garment to be placed in thermal communication with the body; placing a layer of highly conductive fibers within the garment adjacent the body for uniformly distributing the heat generated by the body; attaching an air-moving device in communication with the garment for forcing air into the garment; removably positioning an exchangeable heat sink in communication with the air-moving device for cooling the air prior to the air entering the garment; and, equipping the garment with a channeled sheet in communication with the air-moving device so that air can be directed into the channeled sheet and adjacent the layer of fibers to expell heat and moisture from the body by the air being directed out of the channeled sheet and into the environment. The cooling system may be configured to operate in both sealed and unsealed garments.

  13. Axion Cooling of Neutron Stars

    CERN Document Server

    Sedrakian, Armen

    2015-01-01

    Cooling simulations of neutron stars and their comparison with the data from thermally emitting X-ray sources puts constraints on the properties of axions, and by extension of any light pseudo-scalar dark matter particles, whose existence has been postulated to solve the strong-CP problem of QCD. We incorporate the axion emission by pair-breaking and formation processes by $S$- and $P$-wave nucleonic condensates in a benchmark code for cooling simulations as well as provide fit formulae for the rates of these processes. Axion cooling of neutron stars has been simulated for 24 models covering the mass range 1 to 1.8 solar masses, featuring non-accreted iron and accreted light element envelopes, and a range of nucleon-axion coupling. The models are based on an equation state predicting conservative physics of superdense nuclear matter that does not allow for onset of fast cooling processes induced by phase transitions to non-nucleonic forms of matter or high proton concentration. The cooling tracks in the tempe...

  14. Properties of tangential and radial angles of muons in EAS

    OpenAIRE

    Zabierowski, J.; Daumiller, K.; Doll, P.

    2002-01-01

    Tangential and radial angles of muons in EAS, a useful concept in investigation of the muon production height, can be used also for the investigation of the muon momenta. A parameter zeta, being a combination of tangential and radial angles, is introduced and its possible applications in investigation of muons in showers are presented.

  15. Radial U-band Coma galaxy luminosity functions

    NARCIS (Netherlands)

    Beijersbergen, M; Hoekstra, H; van Dokkum, PG; van der Hulst, JM; Hibbard, JE; Rupen, MP; VanGorkom, JH

    2001-01-01

    We have mapped 1.3 degree(2) of the Coma cluster from the core to beyond the NGC4839 group. Here, we present radial U-band Coma galaxy luminosity functions (LF). The central LF can be represented by a Schechter function, but the radial LFs have very different shapes. We speculate that the derived st

  16. The Radial Velocity Experiment (RAVE) : Second data release

    NARCIS (Netherlands)

    Zwitter, T.; Siebert, A.; Munari, U.; Freeman, K. C.; Siviero, A.; Watson, F. G.; Fulbright, J. P.; Wyse, R. F. G.; Campbell, R.; Seabroke, G. M.; Williams, M.; Steinmetz, M.; Bienayme, O.; Gilmore, G.; Grebel, E. K.; Helmi, A.; Navarro, J. F.; Anguiano, B.; Boeche, C.; Burton, D.; Cass, P.; Dawe, J.; Fiegert, K.; Hartley, M.; Russell, K.; Veltz, L.; Bailin, J.; Binney, J.; Bland-Hawthorn, J.; Brown, A.; Dehnen, W.; Evans, N. W.; Fiorentin, P. Re; Fiorucci, M.; Gerhard, O.; Gibson, B.; Kelz, A.; Kuijken, K.; Matijevic, G.; Minchev, I.; Parker, Q. A.; Penarrubia, J.; Quillen, A.; Read, M. A.; Reid, W.; Roeser, S.; Ruchti, G.; Scholz, R. -D.; Smith, M. C.; Sordo, R.; Tolstoi, E.; Tomasella, L.; Vidrih, S.; De Boer, E. Wylie

    We present the second data release of the Radial Velocity Experiment ( RAVE), an ambitious spectroscopic survey to measure radial velocities and stellar atmosphere parameters ( temperature, metallicity, surface gravity, and rotational velocity) of up to one million stars using the 6 dF multi-object

  17. A case of dextrocardia, radial ray malformation and renal anomaly.

    Science.gov (United States)

    Nallegowda, M; Singh, U; Shivananda; Shukla, R; Kabra, M

    2003-10-01

    A 12-year-old boy is described with bilateral radial club hands, scoliosis, hypospadias, isolated dextrocardia, hypoplastic ribs, an ectopic kidney and spina bifida occulta. Although some of the clinical features of this patient are seen in VATER association and sacrococcygeal dysgenesis, the presence of dextrocardia, facial dysmorphism, radial, renal and vertebral anomalies preclude these diagnoses.

  18. Radial Excitations in the Global Colour Soliton Model

    Institute of Scientific and Technical Information of China (English)

    WANG Bin; LIU Yu-Xin

    2007-01-01

    @@ With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtained masses of the two radial excitations are comparable with the experimental data.

  19. Elbow joint kinematics after excision of the radial head

    DEFF Research Database (Denmark)

    Jensen, Steen Lund; Olsen, Bo Sanderhoff; Søjbjerg, Jens Ole

    1999-01-01

    The contribution of the radial head to elbow joint kinematics was studied in 7 osteoligamentous elbow preparations. During unloaded flexion and extension, radial head excision induced a maximum varus displacement of 1.6 degrees with 20 degrees of joint flexion and a maximum external rotation of 3...

  20. How to obtain Transience from Bounded Radial Mean Curvature

    DEFF Research Database (Denmark)

    Markvorsen, Steen; Palmer, Vicente

    2005-01-01

    We show that Brownian motion on any unbounded submanifold P in an ambient manifold N with a pole P is transient if the following conditions are satisfied: The p-radial mean curvatures of P are sufficiently small outsidea compact set and the p-radial sectional curvatures of N are sufficiently nega...