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Sample records for cooler ring s-lsr

  1. COD correction for laser cooling at S-LSR

    International Nuclear Information System (INIS)

    Souda, Hikaru; Fujimoto, Shinji; Tongu, Hiromu; Shirai, Toshiyuki; Tanabe, Mikio; Ishikawa, Takehiro; Nakao, Masao; Ikegami, Masahiro; Wakita, Akihisa; Iwata, Soma; Fujimoto, Tetsuya; Takeuchi, Takeshi; Noda, Koji; Noda, Akira

    2008-01-01

    A closed orbit is corrected for single-turn injection to perform laser cooling experiments of 40 keV 24 Mg + beam at the small laser-equipped storage ring (S-LSR). Closed orbit distortion (COD) corrections have been carried out using a downhill simplex method, and CODs of less than ±0.5mm have been achieved throughout the whole circumference. The injection orbit and the CODs are optimized to pass through the two aperture holes in the alignment targets located in the laser cooling section with an algorithm to maximize beam lifetime. The CODs at the aperture holes are reduced to be less than ±0.2mm, assuring an overlap between the laser and the 24 Mg + ion beam.

  2. Initial operation of cooler ring, TARN II

    International Nuclear Information System (INIS)

    Katayama, T.; Chida, K.; Honma, T.

    1989-01-01

    TARN II is a heavy ion cooler synchrotron for the studies of accelerator, atomic and nuclear physics, presently being constructed at the Institute for Nuclear Study, University of Tokyo. Its maximum energy is 370 MeV/u for the ions of a charge to mass ratio of q/A = 0.5, corresponding to a magnetic rigidity of 6.1 T·m. The circumference is 77.76 m, just 17 times the extraction orbit of injector cyclotron. Six long straight sections, 4.20 m in length each, are used for the beam injection, extraction, electron cooler and RF accelerating cavity, respectively. At the beginning of 1989, the first experiment of beam injection has been performed successfully with use of 28 MeV α particles. In this paper, the status and initial results of operation of TARN II are presented. (author)

  3. Beam-plasma interaction in a synchrotron-cooler ring

    International Nuclear Information System (INIS)

    Itahashi, T.

    1989-01-01

    We propose a plasma target installed in the synchrotron-cooler ring in order to study the beam-plasma interaction. Various types of beam diagnostic devices and precise techniques developed for stochastic cooling and rf-stacking in the storage ring would be a powerful tool to approach the problems concerning the plasma behavior induced by the beam, such as plasma lens effect, anomalous stopping power and plasma instability. (author)

  4. Studies of Beam Dynamics in Cooler Rings

    International Nuclear Information System (INIS)

    Dietrich, J.; Stein, J.; Meshkov, I.; Sidorin, A.; Smirnov, A.

    2006-01-01

    This report describes the numerical simulation of the crystalline proton beam formation in COSY using BETACOOL code. The study includes the description of experimental results at NAP-M storage ring where the large reduction of the momentum spread was observed for first time. The present simulation shows that this behavior of proton beam can not be explained as ordered state of protons. The numerical simulation of crystalline proton beams was done for COSY parameters. The number of protons when the ordering state can be observed is limited by value 106 particles and momentum spread less then 10-6. Experimental results for the attempt to achieve of ordered state of proton beam for COSY is presented. This work is supported by RFBR grant no. 05-02-16320 and INTAS grant no. 03-54-5584

  5. Data exchange system in cooler-storage-ring virtual accelerator

    International Nuclear Information System (INIS)

    Liu Wufeng; Qiao Weimin; Jing Lan; Guo Yuhui

    2009-01-01

    The data exchange system of the cooler-storage-ring (CSR) control system for heavy ion radiotherapy has been introduced for the heavy ion CSR at Lanzhou (HIRFL-CSR). Using techniques of Java, component object model (COM), Oracle, DSP and FPGA, this system can achieve real-time control of magnet power supplies sanctimoniously, and control beams and their switching in 256 energy levels. It has been used in the commissioning of slow extraction for the main CSR (CSRm), showing stable and reliable performance. (authors)

  6. Cooler Storage Ring at China Institute of Modern Physics

    CERN Document Server

    Wen-Xia, Jia; Zhan, W

    2005-01-01

    CSR, a new ion cooler-storage-ring project in China IMP, is a double ring system, and consists of a main ring (CSRm) and an experimental ring (CSRe). The two existing cyclotrons SFC (K=69) and SSC (K=450) of the Heavy Ion Research Facility in Lanzhou (HIRFL) will be used as its injector system. The heavy ion beams with the energy range of 7-30 MeV/nucleus from the HIRFL will be accumulated, cooled and accelerated to the higher energy range of 100-500 MeV/ nucleus in CSRm, and then extracted fast to produce radioactive ion beams or highly charged heavy ions. Those secondary beams will be accepted and stored or decelerated by CSRe for many internal-target experiments or high precision spectroscopy with beam cooling. On the other hand, the beams with the energy range of 100-1000MeV/ nucleus will also be extracted from CSRm by using slow extraction or fast extraction for many external-target experiments. CSR project was started in the end of 1999 and will be finished in 2006. In this paper the outline and the act...

  7. Accelerator studies at cooler rings TARN and TARN II

    International Nuclear Information System (INIS)

    Katayama, Takeshi.

    1992-07-01

    Two ion cooler rings, TARN and TARN II were constructed and operated from 1975 to 1992 at the Institute for Nuclear Study, Univ. of Tokyo, for mainly accelerator studies concerning the beam accumulation, acceleration and cooling. The main subjects performed in these facilities were; 1) beam stacking in transverse and longitudinal phase spaces, 2) stochastic momentum cooling, 3) electron cooling, 4) synchrotron acceleration and 5) slow beam extraction. In the present paper, typical experimental results on these subjects, arc described as well as the basic physical idea underlying these experimental results. The technical details are out of scope of the present paper. They can be found in the other papers refered in the concerned section in the text. (author)

  8. 6D “Garren” snake cooler and ring cooler for µ{sup ±} cooling of a muon collider

    Energy Technology Data Exchange (ETDEWEB)

    Ding, X., E-mail: xding@bnl.gov [UCLA, Los Angeles, CA 90095 (United States); Berg, J.S. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Cline, D. [UCLA, Los Angeles, CA 90095 (United States); Garren, Al [Particle Beam Lasers, Inc., Northridge, CA 91324 (United States); Kirk, H.G. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2014-12-21

    Six dimensional cooling of large emittance µ{sup +} and µ{sup −} beams is required in order to obtain the desired luminosity for a muon collider. In our previous study, we demonstrated that a 6D “Garren” ring cooler using both dipoles and solenoids in four 90{sup 0} achromatic arcs can give substantial cooling in all six phase space dimensions. In this paper, we describe the injection/extraction requirements of this four-sided ring. We also present the performance of an achromat-based 6D “Garren” snake cooler. The achromatic design permits the design to easily switch between a closed ring and a snaking geometry on injection or extraction from the ring.

  9. Feasibility of beam crystallization in a cooler storage ring

    Directory of Open Access Journals (Sweden)

    Yosuke Yuri

    2005-11-01

    Full Text Available It has been known theoretically that a charged-particle beam circulating in a storage ring exhibits an “ordered” configuration at the space-charge limit. Such an ultimate state of matter is called a crystalline beam whose emittance is ideally equal to zero except for quantum noise. This paper discusses how close one can come to various ordered states by employing currently available accelerator technologies. The dynamic nature of ultracold beams and conditions required for crystallization are briefly reviewed. Molecular dynamics simulations are performed to study the feasibility of this unique phenomenon, considering practical situations in general cooling experiments. It is pointed out that several essential obstacles must be overcome to reach a three-dimensional crystalline state in a storage ring. Doppler laser cooling of ion beams is also numerically simulated to explore the possibility of beam crystallization in an existing machine.

  10. Spin flipping a stored polarized proton beam at the IUCF cooler ring

    International Nuclear Information System (INIS)

    Phelps, R.A.

    1995-01-01

    We recently studied the spin flip of a vertically polarized 139 MeV proton beam stored in the IUCF Cooler Ring. We used an rf solenoid to induce a depolarizing resonance in the ring; we flipped the spin by varying the solenoid field's frequency through this resonance. We found a polarization loss after multiple spin flips less than 0.1% per flip; we also found that this loss increased for very slow frequency changes. This spin flip could reduce systematic errors in stored polarization beam experiments by allowing frequent beam polarization reversals during the experiment. copyright 1995 American Institute of Physics

  11. A radio frequency ring electrode cooler for low-energy ion beams

    International Nuclear Information System (INIS)

    Heinz, S.; Aeystoe, J.; Habs, D.; Hegewisch, S.; Huikari, J.; Nieminen, A.; Rinta-Antila, S.; Schumann, M.; Szerypo, J.

    2004-01-01

    We are investigating a new concept for ion confinement while buffer-gas-cooling low-energy ion beams. Instead of applying the well-established technique of Radio Frequency Quadrupoles (RFQs) where the ions are transversely confined by a quadratic-pseudo potential we are using a stack of thin ring electrodes supplied by an RF field (RF funnel) which creates a box-shaped potential well. In Monte Carlo simulations we have investigated the transmission behavior and cooling performance of the RF funnel. First experimental investigations with ion currents up to 20 nA revealed a promising transmission characteristic which qualifies the RF funnel as high-current cooler

  12. Measurement of RF characteristics of magnetic alloys for an RF cavity of the accumulator cooler ring

    International Nuclear Information System (INIS)

    Watanabe, M.; Chiba, Y.; Katayama, T.; Koseki, T.; Ohtomo, K.; Tsutsui, H.

    2004-01-01

    The magnetic alloy (MA)-loaded RF cavity has been studied for an RF stacking system of the accumulator cooler ring (ACR). RF characteristics of several high-permeability MA cores were measured in the frequency range between 1 and 50 MHz. The effects of the cut-core configuration, cutting the core and leaving air gaps between two circular halves, were also investigated. The results show that the shunt impedance remains high and the appropriate inductance and Q-value can be obtained by increasing the gap width of the cut core in the frequency region of the ACR cavity

  13. Laser spectroscopy with a cooler ring at the ESR (GSI) and the TSR (MPI Heidelberg)

    International Nuclear Information System (INIS)

    Kuehl, T.; Borneis, S.; Greten, G.; Marx, D.; Neumann, R.; Schroeder, S.; Grieser, R.; Hoog, I.; Huber, G.; Klaft, I.; Klein, R.; Merz, P.; Balykin, V.; Bock, M.; Ellert, C.; Forck, P.; Grieser, M.; Grimm, R.; Habs, D.; Miesner, H.J.; Petrich, W.; Wanner, B.; Becker, C.; Schwalm, D.; Wolf, A.

    1992-01-01

    At the TSR cooler ring at Heidelberg, laser studies were carried out using singly charged lithium and beryllium ions. Laser spectroscopy of relativistic lithium ions (υ = 0.04c) yielded signals with a narrow linewidth, suitable for an experimental test of special relativity. A dramatic reduction of the beam temperature, as defined by the longitudinal velocity spread, was achieved via laser cooling in both cases. At the ion energies available at ESR it will become possible to prepare and store bare ions up to U 92+ . Electron cooling was successfully demonstrated for hydrogen-like Bi 82+ ions, where a laser experiment is scheduled to study the ground-state hyperfine splitting. (orig.)

  14. Optimization of the pumping ring in a mechanical seal with an integrated cooler for feed-water pumps

    International Nuclear Information System (INIS)

    Buchdahl, D.; Martin, R.; Gueret, G.; Blanc, M.

    1994-07-01

    To simplify maintenance, E.D.F. along with its collaborators undertook the study of mechanical seal with integrated cooler used in feed-water pumps in the nuclear power plants. The cooler, integrated to the pump acts as a thermal barrier as well as a cooler of the mechanical seal. The water circulation in the cooler is assumed by an integrated pumping ring in the rotary part of the mechanical seal, with a matching screw thread in the pumping case. This assembly of mechanical seal/integrated cooler is tested in a test loop at the EDF/DER Laboratory. All working conditions are similar to that at site. Tests with different configurations of the rotor/stator profiles are performed, i.e.; different lengths and types of threading. Hydraulic performances and the global thermal balance of this assembly are studied. Our basic aim during these tests is to optimize the hydraulic performance of the pumping ring so as to best cool the mechanical seal faces. The different results obtained and the conclusions drawn during these tests are presented. (authors). 7 figs., 3 refs

  15. The physics of highly charged heavy ions revealed by storage/cooler rings

    International Nuclear Information System (INIS)

    Mokler, P.H.; Stoehlker, T.

    1996-01-01

    With the successful commissioning of storage and cooler rings for bright beams of very heavy ions near the threshold of the last decade of this century, not only did a prosperous development in heavy ion accelerator technology come to its present summit, but also fundamental fields in heavy ion physics were opened widely for exciting explorations. Now, essential aspects in this area are accessible, aspects one only dared to dream of another decade ago. In the meantime, great progress already has been made in the fundamental physics in this field. This is particularly true for achievements in the atomic physics of highly charged heavy ions. In this chapter, we present a review of the current advances in this rapidly developing field. There are two general domains to be considered in the atomic physics of highly charged heavy ions: the fields of collisions and of atomic structure. Both aspects have to be explored equally, as they are strongly interconnected. One has to investigate the interaction processes to know, for instance, the population of excited states to help answer questions on the atomic structure; and conversely, one has to know the structure to understand the interactions. In both the fields, fundamental principles can be studied uniquely. This is in particular true for the heaviest ion species with only a few- or even zero-electrons left. 140 refs., 39 figs

  16. A Harmonic Kicker Scheme for the Circulator Cooler Ring in the Proposed Medium Energy Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Nissen, Edward W.; Hutton, Andrew M.; Kimber, Andrew J.

    2013-06-01

    The current electron cooler design for the proposed Medium Energy Electron-Ion collider (MEIC) at Jefferson Lab utilizes a circulator ring for reuse of the cooling electron bunch up to 100 times to cool the ion beams. This cooler requires a fast kicker system for injecting and extracting individual bunches in the circulator ring. Such a kicker must work at a high repetition rate, up to 7.5 to 75 MHz depending on the number of turns in the recirculator ring. It also must have a very short rise and fall time (of order of 1 ns) such that it will kick an individual bunch without disturbing the others in the ring. Both requirements are orders of magnitude beyond the present state-of-the-art as well as the goals of other on-going kicker R&D programs such as that for the ILC damping rings. In this paper we report a scheme of creating this fast, high repetition rate kicker by combining RF waveforms at multiple frequencies to create a kicker waveform that will, for example, kick every eleventh bunch while leaving the other ten unperturbed. We also present a possible implementation of this scheme as well as discuss its limitations.

  17. The Recycler Electron Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Shemyakin, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Prost, L. R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-03-19

    The Recycler Electron cooler was the first (and so far, the only) cooler working at a relativistic energy (γ = 9.5). It was successfully developed in 1995-2004 and was in operation at Fermilab in 2005-2011, providing cooling of antiprotons in the Recycler ring. This paper describes the cooler, difficulties in achieving the required electron beam parameters and the ways to overcome them, cooling measurements, and details of operation.

  18. Three-ring stable oxygen isotope ratios indicating cooler and wetter climate conditions and high flood frequency periods in the Red River Basin, Manitoba, Canada

    International Nuclear Information System (INIS)

    Buhay, W.M.; Harms, P.; Marcino, D.; Mayer, B.; St. George, S.; Nielsen, E.

    2002-01-01

    In the Red River region of southern Manitoba, Canada, the frequency of flood events tends to increase during cooler and wetter climate conditions. Predictably, recorded Red River flood stages are primarily a result of meteorological conditions which produce an increase runoff due to excess snowmelt and heavy spring precipitation. Winter skewed precipitation periods corresponding to cooler and wetter conditions in the Red River Basin may provide traceable oxygen isotope signals in hydrologically sensitive trees occupying the basin. To test this hypothesis, three overlapping oak tree-ring chronologies (KPO1: 1990 to 1795; STVO1: 1985 to 1797; STVO2: 1990 to 1845) were annually sampled and processed for their cellulose

  19. Ultrafast harmonic rf kicker design and beam dynamics analysis for an energy recovery linac based electron circulator cooler ring

    Directory of Open Access Journals (Sweden)

    Yulu Huang

    2016-08-01

    Full Text Available An ultrafast kicker system is being developed for the energy recovery linac (ERL based electron circulator cooler ring (CCR in the proposed Jefferson Lab Electron Ion Collider (JLEIC, previously named MEIC. In the CCR, the injected electron bunches can be recirculated while performing ion cooling for 10–30 turns before the extraction, thus reducing the recirculation beam current in the ERL to 1/10−1/30 (150  mA-50  mA of the cooling beam current (up to 1.5 A. Assuming a bunch repetition rate of 476.3 MHz and a recirculating factor of 10 in the CCR, the kicker is required to operate at a pulse repetition rate of 47.63 MHz with pulse width of around 2 ns, so that only every 10th bunch in the CCR will experience a transverse kick while the rest of the bunches will not be disturbed. Such a kicker pulse can be synthesized by ten harmonic modes of the 47.63 MHz kicker pulse repetition frequency, using up to four quarter wavelength resonator (QWR based deflecting cavities. In this paper, several methods to synthesize such a kicker waveform will be discussed and a comparison of their beam dynamics performance is made using ELEGANT. Four QWR cavities are envisaged with high transverse shunt impedance requiring less than 100 W of total rf power for a Flat-Top kick pulse. Multipole fields due to the asymmetry of this type of cavity are analyzed. The transverse emittance growth due to the sextupole component is simulated in ELEGANT. Off-axis injection and extraction issues and beam optics using a multicavity kick-drift scheme will also be discussed.

  20. Development of a Bunched Beam Electron Cooler based on ERL and Circulator Ring Technology for the Jefferson Lab Electron-Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Stephen V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hannon, Fay E. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hutton, Andrew M. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Rimmer, Robert A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Roblin, Yves R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wang, Haipeng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, He [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2018-01-01

    Jefferson Lab is in the process of designing an electron ion collider with unprecedented luminosity at a 45 GeV center-of-mass energy. This luminosity relies on ion cooling in both the booster and the storage ring of the accelerator complex. The cooling in the booster will use a conventional DC cooler similar to the one at COSY. The high-energy storage ring, operating at a momentum of up to 100 GeV/nucleon, requires novel use of bunched-beam cooling. There are two designs for such a cooler. The first uses a conventional Energy Recovery Linac (ERL) with a magnetized beam while the second uses a circulating ring to enhance both peak and average currents experienced by the ion beam. This presentation will describe the design of both the Circulator Cooling Ring (CCR) design and that of the backup option using the stand-alone ERL operated at lower charge but higher repetition rate than the ERL injector required by the CCR-based design.

  1. Study on the construction of a combined cooler-synchroton ring at the KFA Juelich (COSY study)

    International Nuclear Information System (INIS)

    Gaul, G.; Hagedoorn, H.; Heide, J.A. van der; Hinterberger, F.; Huber, M.; Jahn, R.; Mayer-Kuckuk, T.; Paetz genannt Schieck, H.; Berg, G.; Hardt, A.; Martin, S.; Osterfeld, F.; Prasuhn, D.; Riepe, G.; Rogge, M.; Rossen, P. von; Schult, O.W.B.; Speth, J.; Turek, P.

    1984-02-01

    The project of a storage ring for the extension of the nuclear physics research facilities at the KFA Juelich is presented. Together with the construction of the ring the possibilities for physical research are described. (HSI) [de

  2. Miniature linear cooler development

    International Nuclear Information System (INIS)

    Pruitt, G.R.

    1993-01-01

    An overview is presented of the status of a family of miniature linear coolers currently under development by Hughes Aircraft Co. for use in hand held, volume limited or power limited infrared applications. These coolers, representing the latest additions to the Hughes family of TOP trademark [twin-opposed piston] linear coolers, have been fabricated and tested in three different configurations. Each configuration is designed to utilize a common compressor assembly resulting in reduced manufacturing costs. The baseline compressor has been integrated with two different expander configurations and has been operated with two different levels of input power. These various configuration combinations offer a wide range of performance and interface characteristics which may be tailored to applications requiring limited power and size without significantly compromising cooler capacity or cooldown characteristics. Key cooler characteristics and test data are summarized for three combinations of cooler configurations which are representative of the versatility of this linear cooler design. Configurations reviewed include the shortened coldfinger [1.50 to 1.75 inches long], limited input power [less than 17 Watts] for low power availability applications; the shortened coldfinger with higher input power for lightweight, higher performance applications; and coldfingers compatible with DoD 0.4 Watt Common Module coolers for wider range retrofit capability. Typical weight of these miniature linear coolers is less than 500 grams for the compressor, expander and interconnecting transfer line. Cooling capacity at 80K at room ambient conditions ranges from 400 mW to greater than 550 mW. Steady state power requirements for maintaining a heat load of 150 mW at 80K has been shown to be less than 8 Watts. Ongoing reliability growth testing is summarized including a review of the latest test article results

  3. The COOLER Code

    DEFF Research Database (Denmark)

    Siragusa, Mattia; Baiocco, Giorgio; Fredericia, Nina Pil Møntegaard

    2017-01-01

    COmputation of Local Electron Release (COOLER), a software program designed for dosimetry assessment at the cellular/subcellular scale, with a given distribution of administered low-energy electron-emitting radionuclides in cellular compartments, which remains a critical step in risk/benefit...... calculations with PARTRAC. Results from PARTRAC calculations on electron range, stopping power and residual energy versus traveled distance curves are presented and, when useful for implementation in COOLER, analytical fit functions are given. Example configurations for cells in different culture conditions (V...

  4. Cryogenic cooler thermal coupler

    International Nuclear Information System (INIS)

    Green, K.E.; Talbourdet, J.A.

    1984-01-01

    A thermal coupler assembly mounted to the coldfinger of a cryogenic cooler which provides improved thermal transfer between the coldfinger and the detector assembly mounted on the dewar endwell. The thermal coupler design comprises a stud and spring-loaded cap mounted on the coldfinger assembly. Thermal transfer is made primarily through the air space between the cap and coldwell walls along the radial surfaces. The cap is spring loaded to provide thermal contact between the cap and endwell end surfaces

  5. Microsystem Cooler Development

    Science.gov (United States)

    Moran, Matthew E.; Wesolek, Danielle M.; Berhane, Bruk T.; Rebello, Keith J.

    2004-01-01

    A patented microsystem Stirling cooler is under development with potential application to electronics, sensors, optical and radio frequency (RF) systems, microarrays, and other microsystems. The microsystem Stirling cooler is most suited to volume-limited applications that require cooling below the ambient or sink temperature. Primary components of the planar device include: two diaphragm actuators that replace the pistons found in traditional-scale Stirling machines; and a micro-regenerator that stores and releases thermal energy to the working gas during the Stirling cycle. The use of diaphragms eliminates frictional losses and bypass leakage concerns associated with pistons, while permitting reversal of the hot and cold sides of the device during operation to allow precise temperature control. Three candidate microregenerators were custom fabricated for initial evaluation: two constructed of porous ceramic, and one made of multiple layers of nickel and photoresist in an offset grating pattern. An additional regenerator was prepared with a random stainless steel fiber matrix commonly used in existing Stirling machines for comparison to the custom fabricated regenerators. The candidate regenerators were tested in a piezoelectric-actuated test apparatus designed to simulate the Stirling refrigeration cycle. In parallel with the regenerator testing, electrostatically-driven comb-drive diaphragm actuators for the prototype device have been designed for deep reactive ion etching (DRIE) fabrication.

  6. Electron beam cooling at a magnetic storage ring, TARN II, and an electrostatic storage ring

    International Nuclear Information System (INIS)

    Tanabe, Tetsumi

    2006-01-01

    At the High Energy Accelerator Research Organization (KEK), a magnetic storage ring, TARN II, with an electron cooler was operated from 1989 to 1999, while an electrostatic storage ring with a small electron cooler has been operational since 2000. In this paper, the electron cooling at TARN II and the electrostatic storage ring is described. (author)

  7. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Science.gov (United States)

    2010-07-01

    ... coolers, and final-cooler cooling towers. 61.134 Section 61.134 Protection of Environment ENVIRONMENTAL... Standard: Naphthalene processing, final coolers, and final-cooler cooling towers. (a) No (“zero”) emissions are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke by...

  8. Impulse sales cooler. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Per Henrik (DTI, Taastrup (Denmark))

    2010-11-15

    In the past years, the use of impulse coolers has increased considerably and it is estimated that at least 30.000 are installed in shops in Denmark. In addition, there are many small barrel-shaped can coolers. Most impulse coolers are open, which results in a large consumption of energy, and the refrigeration systems are often quite inefficient. A typical impulse cooler uses app. 5 - 8 kWh/day corresponding to a consumption of energy in the magnitude of 60 GWh/year. For several years, the Danish company Vestfrost A/S has produced an impulse sales cooler in the high-efficiency end and the energy consumption of the cooler is measured to be 4.15 kWh/day. The POS72 cooler formed the baseline of this project. At the start-up meeting in 2008, several ideas were discussed with the objective to reduce energy consumption and to use natural refrigerants. Among the ideas were better air curtains, removable lids, better condensers, use of R600a refrigeration system and better insulation. Three generations of prototypes were built and tested in a climate chamber at Danish Technological Institute and the third generation showed very good performance: the energy consumption was measured to 2.215 kWh/day, which is a 47% reduction compared to the baseline. That was achieved by: 1) Improving the cold air cycling system including the air curtain. 2) Using the natural refrigerant R600a (isobutane) and the Danfoss NLE9KTK compressor, which has better efficiency compared to the compressor in the baseline product. 3) Using a box type condenser without fins (preventing dust build-up) and with a relatively high surface area. 4) Improving the insulation value of the plastic cabinet by reducing turbulence in the air gap between the plastic walls and improving the insulation value of the EPS moulded insulation surrounding the refrigeration system at the bottom of the cooler. 5) Preventing short-circuit of warm air around the condenser. 6) The improvements are cost efficient and will not add

  9. ENERGY STAR Certified Water Coolers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Water Coolers that are effective as of February...

  10. Thermoelectric coolers as power generators

    International Nuclear Information System (INIS)

    Burke, E.J.; Buist, R.J.

    1984-01-01

    There are many applications where thermoelectric (TE) coolers can be used effectively as power generators. The literature available on this subject is scarce and very limited in scope. This paper describes the configuration, capability, limitations and performance of TE coolers to be used as power generators. Also presented are performance curves enabling the user to design the optimum TE module for any given power generation application

  11. Development of the Sandia Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry Alan [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Koplow, Jeffrey P. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Staats, Wayne Lawrence [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Curgus, Dita Brigitte [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Leick, Michael Thomas. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Matthew, Ned Daniel [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Zimmerman, Mark D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Arienti, Marco [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Gharagozloo, Patricia E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hecht, Ethan S. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Spencer, Nathan A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Vanness, Justin William. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Gorman, Ryan [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2013-12-01

    This report describes an FY13 effort to develop the latest version of the Sandia Cooler, a breakthrough technology for air-cooled heat exchangers that was developed at Sandia National Laboratories. The project was focused on fabrication, assembly and demonstration of ten prototype systems for the cooling of high power density electronics, specifically high performance desktop computers (CPUs). In addition, computational simulation and experimentation was carried out to fully understand the performance characteristics of each of the key design aspects. This work culminated in a parameter and scaling study that now provides a design framework, including a number of design and analysis tools, for Sandia Cooler development for applications beyond CPU cooling.

  12. MEMS Stirling Cooler Development Update

    Science.gov (United States)

    Moran, Matthew E.; Wesolek, Danielle

    2003-01-01

    This presentation provides an update on the effort to build and test a prototype unit of the patented MEMS Stirling cooler concept. A micro-scale regenerator has been fabricated by Polar Thermal Technologies and is currently being integrated into a Stirling cycle simulator at Johns Hopkins University Applied Physics Laboratory. A discussion of the analysis, design, assembly, and test plans for the prototype will be presented.

  13. Surface tension confined liquid cryogen cooler

    Science.gov (United States)

    Castles, Stephen H. (Inventor); Schein, Michael E. (Inventor)

    1989-01-01

    A cryogenic cooler is provided for use in craft such as launch, orbital, and space vehicles subject to substantial vibration, changes in orientation, and weightlessness. The cooler contains a small pore, large free volume, low density material to restrain a cryogen through surface tension effects during launch and zero-g operations and maintains instrumentation within the temperature range of 10 to 140 K. The cooler operation is completely passive, with no inherent vibration or power requirements.

  14. Pulse tube coolers for Meteosat third generation

    International Nuclear Information System (INIS)

    Butterworth, James; Aigouy, Gérald; Chassaing, Clement; Debray, Benoît; Huguet, Alexandre

    2014-01-01

    Air Liquide's Large Pulse Tube Coolers (LPTC) will be used to cool the focal planes of the Infrared Sounder (IRS) and Flexible Combined Imager (FCI) instruments aboard the ESA/Eumetsat satellites Meteosat Third Generation (MTG). This cooler consists of an opposed piston linear compressor driving a pulse tube cold head and the associated drive electronics including temperature regulation and vibration cancellation algorithms. Preparations for flight qualification of the cooler are now underway. In this paper we present results of the optimization and qualification activities as well as an update on endurance testing

  15. Mitigation of Syngas Cooler Plugging and Fouling

    Energy Technology Data Exchange (ETDEWEB)

    Bockelie, Michael J. [Reaction Engineering International, Salt Lake City, UT (United States)

    2015-06-29

    This Final Report summarizes research performed to develop a technology to mitigate the plugging and fouling that occurs in the syngas cooler used in many Integrated Gasification Combined Cycle (IGCC) plants. The syngas cooler is a firetube heat exchanger located downstream of the gasifier. It offers high thermal efficiency, but its’ reliability has generally been lower than other process equipment in the gasification island. The buildup of ash deposits that form on the fireside surfaces in the syngas cooler (i.e., fouling) lead to reduced equipment life and increased maintenance costs. Our approach to address this problem is that fouling of the syngas cooler cannot be eliminated, but it can be better managed. The research program was funded by DOE using two budget periods: Budget Period 1 (BP1) and Budget Period 2 (BP2). The project used a combination of laboratory scale experiments, analysis of syngas cooler deposits, modeling and guidance from industry to develop a better understanding of fouling mechanisms and to develop and evaluate strategies to mitigate syngas cooler fouling and thereby improve syngas cooler performance. The work effort in BP 1 and BP 2 focused on developing a better understanding of the mechanisms that lead to syngas cooler plugging and fouling and investigating promising concepts to mitigate syngas cooler plugging and fouling. The work effort focused on the following: • analysis of syngas cooler deposits and fuels provided by an IGCC plant collaborating with this project; • performing Jet cleaning tests in the University of Utah Laminar Entrained Flow Reactor to determine the bond strength between an ash deposit to a metal plate, as well as implementing planned equipment modifications to the University of Utah Laminar Entrained Flow Reactor and the one ton per day, pressurized Pilot Scale Gasifier; • performing Computational Fluid Dynamic modeling of industrially relevant syngas cooler configurations to develop a better

  16. Oxide-cathode activation and surface temperature calculation of electron cooler

    International Nuclear Information System (INIS)

    Li Jie; Yang Xiaodong; Mao Lijun; Li Guohong; Yuan Youjin; Liu Zhanwen; Zhang Junhui; Yang Xiaotian; Ma Xiaoming; Yan Tailai

    2011-01-01

    The pollution on electron gun ceramic insulation of electron cooler restricted the operation of electron cooler at HIRFL-CSR main ring. To cool and accumulate ion beam well, the pollution was cleared and a new oxide-coated cathode was assembled. The processes of cathode replacement,vacuum chamber baking-out, and thermal decomposition of coating binders and alkaline earth metal carbonates, and cathode activation are presented. The electron gun perveance of 10.6 μA/V 1.5 was attained under the heating power of 60 W. The typical surface temperature of oxide-coated cathode that is calculated through grey-body radiation is 1 108 K which shows a comparable result to the experimental measurement 1 078 K. The perveance growth of electron gun during the electron cooler operation is also explained by partial activation of the cathode. (authors)

  17. Small high cooling power space cooler

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, T. V.; Raab, J.; Durand, D.; Tward, E. [Northrop Grumman Aerospace Systems Redondo Beach, Ca, 90278 (United States)

    2014-01-29

    The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the advent of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.

  18. Commissioning of HIRFL-CSR and its Electron Coolers

    International Nuclear Information System (INIS)

    Yang Xiaodong; Zhan Wenlong; Xia Jiawen; Zhao Hongwei; Yuan Youjin; Song Mingtao; Li Jie; Mao Lijun; Lu Wang; Wang Zhixue; Parkhomchuk, Vasily

    2006-01-01

    The brief achievements of HIRFL-CSR commissioning and the achieved parameters of its coolers were presented. With the help of electron cooling code, the cooling time of ion beam were extensive simulated in various parameters of the ion beam in the HIRFL-CSR electron cooling storage rings respectively, such as ion beam energy, initial transverse emittance, and momentum spread. The influence of the machine lattice parameters-betatron function, and dispersion function on the cooling time was investigated. The parameters of electron beam and cooling devices were taken into account, such as effective cooling length, magnetic field strength and its parallelism in cooling section, electron beam size and density. As a result, the lattice parameters of HIRFL-CSR were optimal for electron cooling, and the parameters of electron beam can be optimized according to the parameters of heavy ion beam

  19. Low Energy Electron Cooler for NICA Booster

    CERN Document Server

    Denisov, A P

    2017-01-01

    BINP has developed an electron cooler to increase the ion accumulation efficiency in the NICA (Nuclotron-based Ion Collider fAcility) heavy ion booster (JINR, Dubna). Adjustment of the cooler magnetic system provides highly homogeneous magnetic field in the cooling section B trans/B long ≤ 4∙10-5 which is vital for efficient electron cooling. First experiments with an electron beam performed at BINP demonstrated the target DC current of 500 mA and electron energy 6 keV.

  20. Microsystem Cooler Concept Developed and Being Fabricated

    Science.gov (United States)

    Moran, Matthew E.

    2005-01-01

    A patented microsystem cooler concept has been developed by the NASA Glenn Research Center. It incorporates diaphragm actuators to produce the Stirling refrigeration cycle within a planar configuration compatible with the thermal management of electronics, sensors, optical and radiofrequency systems, microarrays, and other microsystems. The microsystem cooler is most suited to volume-limited applications that require cooling below the ambient or sink temperature. Johns Hopkins University Applied Physics Laboratory is conducting development testing and fabrication of a prototype under a grant from Glenn.

  1. Improvement In The COP Of Thermoelectric Cooler

    Directory of Open Access Journals (Sweden)

    Jatin Patel

    2015-08-01

    Full Text Available This paper described the study for heat transfer through thermoelectric cooler TEC by use of multistage thermoelectric module. To satisfy the heat dissipation of modern electronic element thermal designers have to increase fin area and fan speed to improve its cooling capacity. However the increase of fin area is restricted by the space. Besides the increase of fan speed would induce noise which damages human health. So air cooling by fan is hardly to meet the requirement of modern electronic component. Recently thermoelectric cooler TEC is applied to electronic cooling with the advantages of small size quietness and reliability. A typical thermoelectric cooler consists of p-type and n-type semiconductor pellets connected electrically in series and sandwiched between two ceramic substrates. Whenever direct current passes through the circuit it causes temperature differential between TEC sides. As a result one face of TEC which is called cold side will be cooled while its opposite face which is called hot side is simultaneously heated. The main problem over the use of TEC is the limited COP and its thermal performance. But these can be eliminated by use of multistage thermoelectric cooler.

  2. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

    The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

  3. Fuel cell cooler-humidifier plate

    Science.gov (United States)

    Vitale, Nicholas G.; Jones, Daniel O.

    2000-01-01

    A cooler-humidifier plate for use in a proton exchange membrane (PEM) fuel cell stack assembly is provided. The cooler-humidifier plate combines functions of cooling and humidification within the fuel cell stack assembly, thereby providing a more compact structure, simpler manifolding, and reduced reject heat from the fuel cell. Coolant on the cooler side of the plate removes heat generated within the fuel cell assembly. Heat is also removed by the humidifier side of the plate for use in evaporating the humidification water. On the humidifier side of the plate, evaporating water humidifies reactant gas flowing over a moistened wick. After exiting the humidifier side of the plate, humidified reactant gas provides needed moisture to the proton exchange membranes used in the fuel cell stack assembly. The invention also provides a fuel cell plate that maximizes structural support within the fuel cell by ensuring that the ribs that form the boundaries of channels on one side of the plate have ends at locations that substantially correspond to the locations of ribs on the opposite side of the plate.

  4. The Cooling of a Liquid Absorber using a Small Cooler

    International Nuclear Information System (INIS)

    Baynham, D.E.; Bradshaw, T.W.; Green, M.A.; Ishimoto, S.; Liggins, N.

    2005-01-01

    This report discusses the use of small cryogenic coolers for cooling the Muon Ionization Cooling Experiment (MICE) liquid cryogen absorbers. Since the absorber must be able contain liquid helium as well liquid hydrogen, the characteristics of the available 4.2 K coolers are used here. The issues associated with connecting two-stage coolers to liquid absorbers are discussed. The projected heat flows into an absorber and the cool-down of the absorbers using the cooler are presented. The warm-up of the absorber is discussed. Special hydrogen safety issues that may result from the use of a cooler on the absorbers are also discussed

  5. Radiant coolers - Theory, flight histories, design comparisons and future applications

    Science.gov (United States)

    Donohoe, M. J.; Sherman, A.; Hickman, D. E.

    1975-01-01

    Radiant coolers have been developed for application to the cooling of infrared detectors aboard NASA earth observation systems and as part of the Defense Meteorological Satellite Program. The prime design constraints for these coolers are the location of the cooler aboard the satellite and the satellite orbit. Flight data from several coolers indicates that, in general, design temperatures are achieved. However, potential problems relative to the contamination of cold surfaces are also revealed by the data. A comparison among the various cooler designs and flight performances indicates design improvements that can minimize the contamination problem in the future.

  6. Results from the Cooler and Lead Tests

    International Nuclear Information System (INIS)

    Green, Michael A.

    2010-01-01

    The report presents the results of testing MICE spectrometer magnet current leads on a test apparatus that combines both the copper leads and the high temperature superconducting (HTS) leads with a single Cryomech PT415 cooler and liquid helium tank. The current is carried through the copper leads from 300 K to the top of the HTS leads. The current is then carried through the HTS leads to a feed-through from the vacuum space to the inside of a liquid helium tank. The experiment allows one to measure the performance of both cooler stages along with the performance of the leads. While the leads were powered we measured the voltage drops through the copper leads, through the HTS leads, through spliced to the feed-through, through the feed-through and through the low-temperature superconducting loop that connects one lead to the other. Measurements were made using the leads that were used in spectrometer magnet 1A and spectrometer magnet 2A. These are the same leads that were used for Superbend and Venus magnets at LBNL. The IL/A for these leads was 5.2 x 10 6 m -1 . The leads turned out to be too long. The same measurements were made using the leads that were installed in magnet 2B. The magnet 2B leads had an IL/A of 3.3 x 10 6 A m -1 . This report discusses the cooler performance and the measured electrical performance of the lead circuit that contains the copper leads and the superconducting leads. All of the HTS leads that were installed in magnet 2B were current tested using this apparatus.

  7. Heat driven thermoacoustic cooler based on traveling-standing wave

    International Nuclear Information System (INIS)

    Kang Huifang; Zhou Gang; Li Qing

    2010-01-01

    This paper presents a heat driven thermoacoustic cooler system without any moving part. It consists of a thermoacoustic engine and a thermoacoustic cooler, and the former is the driving source of the latter. Both the engine and the cooler are located in one loop tube coupled with a resonator tube, and the acoustic power produced by the engine is used to drive the cooler directly. Both regenerators of the engine and the cooler are located in the near region of the pressure antinode, and operate in traveling-standing wave phase region. In the engine's regenerator, both components of the standing wave and the traveling wave realize the conversion from heat to acoustic energy. This improves the efficiency of the engine. In the cooler's regenerator, both components of the traveling wave and the standing wave pump heat from the cold end. This improves the efficiency of the cooler. At the operating point with a mean pressure of 22 bar, helium as working gas, a frequency of 234 Hz, and a heating power of 300 W, the experimental cooler provides a no-load temperature of -30 deg. C and a cooling power of 40 W at the cooling temperature of 0 deg. C. The total length of this cooler system is less than 1 m, which shows a good prospect for the domestic cooler system in room-temperature cooling such as food refrigeration and air-conditioning.

  8. Development of a small Stirling cycle cooler for spaceflight applications

    International Nuclear Information System (INIS)

    Werrett, S.T.; Bradshaw, T.W.; Davey, G.; Delderfield, T.W.; Peskett, G.D.

    1986-01-01

    This paper describes the development, from a previously proven design approach, of a robust and simple Stirling cycle cooler with long life potential. The need for a closed cycle refrigerator for use in a spacecraft borne infra-red radiometer is explained. The refrigerator is to supply 1 watt of cooling at 80 K for less than 80 watts of input power, be able to survive the launch environment and subsequently run for 26000 hours. Clearance seals achieved with a spring suspension developed from earlier space proven mechanisms have led to the production of a linear split Stirling cycle machine with no apparent life limiting features. A servo control system, in conjunction with moving coil motors and LVDT position sensors, permits running of balanced pairs of mechanisms. The working fluid, helium at a pressure of 1.2 MPa, is contained within titanium bodies having gold O-ring seals. A vacuum bakeout procedure, based upon experience and outgassing trials, reduces residual contaminant release to acceptable levels. A prototype refrigerator has been subjected to a vibration test and has subsequently run for 6000 hours with no detectable change in performance

  9. Consideration of Relativistic Dynamics in High-Energy Electron Coolers

    CERN Document Server

    Bruhwiler, David L

    2005-01-01

    A proposed electron cooler for RHIC would use ~55 MeV electrons to cool fully-ionized 100 GeV/nucleon gold ions.* At two locations in the collider ring, the electrons and ions will co-propagate for ~13 m, with velocities close to c and gamma>100. To lowest-order, one can Lorentz transform all physical quantities into the beam frame and calculate the dynamical friction forces assuming a nonrelativisitc, electrostatic plasma. However, we show that nonlinear space charge forces of the bunched electron beam on the ions must be calculated relativistically, because an electrostatic beam-frame calculation is not valid for such short interaction times. The validity of nonrelativistic friction force calculations must also be considered. Further, the transverse thermal velocities of the high-charge (~20 nC) electron bunch are large enough that some electrons have marginally relativistic velocities, even in the beam frame. Hence, we consider relativistic binary collisions – treating the model problem of ...

  10. Thermoelectric Coolers with Sintered Silver Interconnects

    Science.gov (United States)

    Kähler, Julian; Stranz, Andrej; Waag, Andreas; Peiner, Erwin

    2014-06-01

    The fabrication and performance of a sintered Peltier cooler (SPC) based on bismuth telluride with sintered silver interconnects are described. Miniature SPC modules with a footprint of 20 mm2 were assembled using pick-and-place pressure-assisted silver sintering at low pressure (5.5 N/mm2) and moderate temperature (250°C to 270°C). A modified flip-chip bonder combined with screen/stencil printing for paste transfer was used for the pick-and-place process, enabling high positioning accuracy, easy handling of the tiny bismuth telluride pellets, and immediate visual process control. A specific contact resistance of (1.4 ± 0.1) × 10-5 Ω cm2 was found, which is in the range of values reported for high-temperature solder interconnects of bismuth telluride pellets. The realized SPCs were evaluated from room temperature to 300°C, considerably outperforming the operating temperature range of standard commercial Peltier coolers. Temperature cycling capability was investigated from 100°C to 235°C over more than 200 h, i.e., 850 cycles, during which no degradation of module resistance or cooling performance occurred.

  11. Solution for Direct Solar Impingement Problem on Landsat-7 ETM+ Cooler Door During Cooler Outgas in Flight

    Science.gov (United States)

    Choi, Michael K.

    1999-01-01

    There was a thermal anomaly of the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) radiative cooler cold stage during the cooler outgas phase in flight. With the cooler door in the outgas position and the outgas heaters enabled, the cold stage temperature increased to a maximum of 323 K when the spacecraft was in the sunlight, which was warmer than the 316.3 K upper set point of the outgas heater controller on the cold stage. Also, the outgas heater cycled off when the cold stage was warming up to 323 K. A corrective action was taken before the attitude of the spacecraft was changed during the first week in flight. One orbit before the attitude was changed, the outgas heaters were disabled to cool off the cold stage. The cold stage temperature increase was strongly dependent on the spacecraft roll and yaw. It provided evidence that direct solar radiation entered the gap between the cooler door and cooler shroud. There was a concern that the direct solar radiation could cause polymerization of hydrocarbons, which could contaminate the cooler and lead to a thermal short. After outgas with the cooler door in the outgas position for seven days, the cooler door was changed to the fully open position. With the cooler door fully open, the maximum cold stage temperature was 316.3 K when the spacecraft was in the sunlight, and the duty cycle of the outgas heater in the eclipse was the same as that in the sunlight. It provided more evidence that direct solar radiation had entered the gap between the cooler door and cooler shroud. Cooler outgas continued for seven more days, with the cooler door fully open. The corrective actions had prevented overheating of the cold stage and cold focal plane array (CFPA), which could damage these two components. They also minimized the risk of contamination on the cold stage, which could lead to a thermal short.

  12. Performance characterization of the TRW 35K pulse tube cooler

    International Nuclear Information System (INIS)

    Collins, S.A.; Johnson, D.L.; Smedley, G.T.; Ross, R.G. Jr.

    1996-01-01

    The TRW 35K pulse tube cooler is configured as an integral cooler, with the pulse tube attached perpendicular to a pair of compressors operating into a common compression chamber. The cooler was optimized for 35K operation and has a nominal cooling capacity of 850 mW at 35 K with a cooler input power of 200 W. It also provides 2 W of cooling at 60 K for 90 W of input power. The cooler was extensively characterized by JPL, measuring the thermal performance and the cooler-generated vibration and EMI as a function of piston stroke and offset position. The thermal performance was found to be quite sensitive to the piston offset position. The pulse tube parasitic conduction levels were also measured and shown to have a strong angular dependence relative to gravity. Magnetic shielding studies were performed to examine radiated magnetic emission levels from compressors with and without shielding

  13. Criticality safety study of shutdown diffusion cascade coolers

    International Nuclear Information System (INIS)

    Paschal, L.S.; Basoglu, B.; Bentley, C.L.; Dunn, M.E.

    1996-01-01

    Gaseous diffusion plants use cascade coolers in the production of highly enriched uranium (HEU) to remove heat from the enriched stream of UF 6 . The cascade coolers operate like shell and tube heat exchangers with the UF 6 on the shell side and Freon on the tube side. Recirculating cooling water (RCW) in condensers is used to cool the Freon. A criticality safety analysis was previously performed for cascade coolers during normal operation. The purpose of this paper is to evaluate several different hypothetical accidents regarding RCW ingress into the cooler to determine whether criticality safety concerns exist

  14. Indirect evaporative coolers with enhanced heat transfer

    Science.gov (United States)

    Kozubal, Eric; Woods, Jason; Judkoff, Ron

    2015-09-22

    A separator plate assembly for use in an indirect evaporative cooler (IEC) with an air-to-air heat exchanger. The assembly includes a separator plate with a first surface defining a dry channel and a second surface defining a wet channel. The assembly includes heat transfer enhancements provided on the first surface for increasing heat transfer rates. The heat transfer enhancements may include slit fins with bodies extending outward from the first surface of separator plate or may take other forms including vortex generators, offset strip fins, and wavy fins. In slit fin implementations, the separator plate has holes proximate to each of the slit fins, and the separator plate assembly may include a sealing layer applied to the second surface of the separator plate to block air flow through the holes. The sealing layer can be a thickness of adhesive, and a layer of wicking material is applied to the adhesive.

  15. Surface tension confined liquid cryogen cooler

    International Nuclear Information System (INIS)

    Castles, S.H.; Schein, M.E.

    1989-01-01

    A cryogenic cooler is described for use in craft such as launch, orbital and space vehicles subject to changes in orientation and conditions of vibration and weightlessness comprising: an insulated tank; a porous open celled sponge-like material disposed substantially throughout the contained volume of the insulated tank; a cryogenic fluid disposed within the sponge-like material; a cooling finger immersed in the cryogenic fluid, the finger extending from inside the insulated tank externally to an outside source such as an instrument detector for the purpose of transmitting heat from the outside source into the cryogenic fluid; means for filling the insulated tank with cryogenic fluid; and means for venting vaporized cryogenic fluid from the insulated tank

  16. The Liquefaction of Hydrogen and Helium Using Small Coolers

    International Nuclear Information System (INIS)

    Green, Michael A.

    2006-01-01

    This report discusses the history of the liquefaction of hydrogen and helium using small coolers. This history dates form the 1960's when two stage GM coolers capable of reaching 7 K were used to liquefy helium and hydrogen by suing an added compressor and J-T circuit. Liquefaction using the added circuit failed to become mainstream because the J-T valve and heat exchanger clogged because of impurities in the gas being liquefied. Liquefaction using a GM cooler without an added J-T circuit proved to be difficult because the first stage was not used to pre-cool the gas coming to the second stage of the cooler. Once the gas being liquefied was pre-cooled using the cooler first stage, improvements in the liquefaction rates were noted. The advent of low temperature pulse tube cooler (down to 2.5 K) permitted one to achieve dramatic improvement is the liquefactions rates for helium. Similar but less dramatic improvements are expected for hydrogen as well. Using the PT-415 cooler, one can expect liquefaction rates of 15 to 20 liters per day for helium or hydrogen provided the heat leak into the cooler and the storage vessel is low. A hydrogen liquefier for MICE is presented at the end of this report

  17. Development of a 15 K hydrogen-based sorption cooler

    NARCIS (Netherlands)

    Burger, Johannes Faas; Holland, Herman J.; Meijer, R.J.; Linder, M.; ter Brake, Hermanus J.M.

    2010-01-01

    At the University of Twente, a 15 K hydrogen-based sorption cooler is under development, which has no moving parts and, therefore, is essentially vibration-free. Moreover, it has the potential of a very long life. Although the cooler may operate standalone, it is designed to precool a helium-based

  18. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S

    2006-01-01

    A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

  19. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

    1998-01-05

    White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

  20. Experimental investigation of a super performance dew point air cooler

    International Nuclear Information System (INIS)

    Xu, Peng; Ma, Xiaoli; Zhao, Xudong; Fancey, Kevin

    2017-01-01

    Highlights: •The cooler had a complex heat & mass exchanger with an advanced wet material layer. •Intermittent water supply scheme was implemented. •The cooler achieved 100–160% higher COP compared to the existing dew point coolers. •Electricity use of the cooler was reduced by 50–70% compared to existing dew coolers. •This optimal working air ratio was 0.364 that enabled maximised cooling effectiveness. -- Abstract: This paper presents an experimental investigation of a super performance dew point air cooler which, by employing a super performance wet material layer, innovative heat and mass exchanger and intermittent water supply scheme, has achieved a significantly higher energy efficiency (i.e. Coefficient of Performance, COP) and a much lower electrical energy use compared to the existing air coolers of the same type. This involves the dedicated system design & construction, fully planned experimental testing under various simulated climatic conditions representing the climate of hot & dry, warm & dry, moderate, warm & humid and standard lab testing condition, testing results analysis and discussion, as well as the parallel comparison against the commercial dew point air cooler. Under the standard test condition, i.e. dry bulb temperature of 37.8 °C and coincident wet bulb temperature of 21.1 °C, the prototype cooler achieved the wet-bulb cooling effectiveness of 114% and dew-point cooling effectiveness of 75%, yielding a significantly high COP value of 52.5 at the optimal working air ratio of 0.364. The testing also indicated that the lower inlet air relative humidity led to a higher cooling efficiency, while the lower cooling output helped increase COP and cooling effectiveness (including the wet-bulb effectiveness and dew-point effectiveness) of the cooler.

  1. First use of a laser-driven polarized H/D target at the IUCF cooler

    International Nuclear Information System (INIS)

    Bailey, K.; Brack, J.; Cadman, R. V.; Cummings, W. J.; Fedchak, J.; Fox, B.; Gao, H.; Grosshauser, C.; Holt, R. J.; Jones, C.; Kinney, E.; Kowalczyk, R.; Lu, Z.-T.; Miller, M. A.; Nagengast, W.; Owen, B.; Rith, K.; Schmidt, F.; Schulte, E.; Sowinski, J.; Sperisen, F.; Stenger, J.; Thorsland, E.; Williamson, S.

    1997-01-01

    The HERMES Laser-Driven Target Task Force (Argonne, Erlangen and Illinois) is charged with developing a polarized H/D target for use in the HERA ring at DESY. Rapid progress was made in the beginning of 1996, leading us to the decision to test the target in a realistic experimental environment. In particular, polarizations of 0.6 and flows above 10 18 atoms·s -1 have been achieved on the bench. The laser-driven target and a simple detector system are currently installed in Cooler storage ring at the Indiana University Cyclotron Facility in order to test its applicability to nuclear physics experiments. Target polarizations are being measured using the rvec H(p, p) and rvec D(p, p) reactions. Initial tests were reasonably successful and the target is well along toward becoming viable for nuclear physics

  2. Thermoelectric cooler application in electronic cooling

    International Nuclear Information System (INIS)

    Chein Reiyu; Huang Guanming

    2004-01-01

    This study addresses thermoelectric cooler (TEC) applications in the electronic cooling. The cold side temperature (T c ) and temperature difference between TEC cold and hot sides (ΔT=T h -T c , T h =temperature of hot side of TEC) were used as the parameters. The cooling capacity, junction temperature, coefficient of performance (COP) of TEC and the required heat sink thermal resistance at the TEC hot side were computed. The results indicated that the cooling capacity could be increased as T c increased and ΔT was reduced. The maximum cooling capacity and chip junction temperature obtained were 207 W and 88 deg. C, respectively. The required heat sink thermal resistance on TEC hot side was 0.054 deg. C/W. Larger cooling capacity and higher COP could be obtained when the TEC was operated in the enforced regimes (ΔT c values and heat sink thermal resistance at the TEC hot side. A microchannel heat sink using water or air as the coolant was demonstrated to meet the low thermal heat sink resistance requirement for TEC operated at maximum cooling capacity conditions

  3. Efficiency of the Fermilab Electron Cooler's Collector

    CERN Document Server

    Prost, L R

    2005-01-01

    The newly installed high-energy Recycler Electron Cooling system (REC) at Fermilab will work at an electron energy of 4.34 MeV and a DC beam current of 0.5 A in an energy recovery scheme. For reliable operation of the system, the relative beam current loss must be maintained to levels < 3.e-5. Experiments have shown that the loss is determined by the performance of the electron beam collector, which must retain secondary electrons generated by the primary beam hitting its walls. As a part of the Electron cooling project, the efficiency of the collector for the REC was optimized, both with dedicated test bench experiments and on two versions of the cooler prototype. We find that to achieve the required relative current loss, an axially-symmetric collector must be immersed in a transverse magnetic field with certain strength and gradient prescriptions. Collector efficiencies in various magnetic field configurations, including without a transverse field on the collector, are presented and discussed

  4. Beam accumulation with the SIS electron cooler

    International Nuclear Information System (INIS)

    Steck, M.; Groening, L.; Blasche, K.; Franczak, B.; Franzke, B.; Winkler, T.; Parkhomchuk, V.V.

    2000-01-01

    An electron cooling system has started operation in the heavy ion synchrotron SIS which is used to increase the intensity for highly charged ions. Fast transverse cooling of the hot ion beam after horizontal multiturn injection allows beam accumulation at the injection energy. After optimization of the accumulation process an intensity increase in a synchrotron pulse by more than one order of magnitude has been achieved. For highly charged ions the maximum number of particles has been increased from 1x10 8 to 1x10 9 . For lighter ions intensity limitations have been encountered which are caused by the high phase space density of the cooled ion beam. Momentum spreads in the 10 -4 range and emittances well below 10 π mm mrad have been demonstrated. Recombination losses both in the residual gas and with the free cooler electrons determine the maximum intensity for highly charged ions. Systematic measurements of the recombination rates have been performed providing data for an optimum choice of the charge state. Strong enhancement of the recombination rate with free electrons compared to theoretical calculations of radiative electron capture have been observed

  5. Development of a hybrid cooler; Udvikling af hybridkoeler

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, P.; Toftegaard, R.; Weinkauff Kristoffersen, J. [Teknologisk Institut, Aarhus (Denmark); Juel Skovrup, M. [IPU, Kgs. Lyngby (Denmark); Ibsen, C. [VP Industries, Lem (Denmark)

    2013-04-15

    The project aims to develop a hybrid cooler which acts as a dry cooler in the winter and as cooling tower in summer. Energy consumption for cooling systems with a dry cooler and a cooling tower, respectively, is comparable in the winter months. This phase 1 of the project shows that improvements of 50-100% on the performance of a hybrid cooler can be achieved as compared to a dry cooler. The improvement is achieved by humidifying the air with recirculated water through nozzles so that the air temperature decreases from the dry temperature to the wet temperature, and that the dry cooler surface is humidified with a film of water, which increases the heat transfer coefficient considerably compared to a dry surface. The experiments showed that a humidifier system cannot be used without further action. At face velocities less than 5 m/s the humidification does not yield any improvement, and in some cases the heat transfer in a standard dry cooler is decreased. This is due to entrainment of not fully vaporized droplets which are deposited between the dry cooler fins and form bridges that block parts of the cooler. By modifying the surface characteristics with a coating, it will be possible to drain the water away so that no bridges are formed. The company Accoat, which makes special surfaces, will therefore be associated to phase 2 of the project. Another aspect that was evident in the tests, is the formation of biofilm on the heat exchanger surface, which can reduce performance by up to 25%. Biofilm can be prevented by treating the feed water, and therefore Danish Clean Water A/S associated to phase 2 of the project, as they produce water purification systems for biofouling decomposition. (LN)

  6. Cooling performance of helium-gas/water coolers in HENDEL

    International Nuclear Information System (INIS)

    Inagaki, Yoshiyuki; Takada, Shoji; Hayashi, Haruyoshi; Kobayashi, Toshiaki; Ohta, Yukimaru; Shimomura, Hiroaki; Miyamoto, Yoshiaki

    1994-01-01

    The helium engineering demonstration loop (HENDEL) has four helium-gas/water coolers where the cooling water flows in the tubes and helium gas on the shell side. Their cooling performance was studied using the operational data from 1982 to 1991. The heat transfer of helium gas on the shell was obtained for segmental and step-up baffle type coolers. Also, the change with operation time was investigated. The cooling performance was lowered by the graphite powder released from the graphite components for several thousand hours and thereafter recovered because the graphite powder from the components was reduced and the powder in the cooler shell was blown off during the operation. (orig.)

  7. Vortex rings

    CERN Document Server

    Akhmetov, D G

    2009-01-01

    This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.

  8. Mid Infrared Instrument cooler subsystem test facility overview

    Science.gov (United States)

    Moore, B.; Zan, J.; Hannah, B.; Chui, T.; Penanen, K.; Weilert, M.

    2017-12-01

    The Cryocooler for the Mid Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) provides cooling at 6.2K on the instrument interface. The cooler system design has been incrementally documented in previous publications [1][2][3][4][5]. It has components that traverse three primary thermal regions on JWST: Region 1, approximated by 40K; Region 2, approximated by 100K; and Region 3, which is at the allowable flight temperatures for the spacecraft bus. However, there are several sub-regions that exist in the transition between primary regions and at the heat reject interfaces of the Cooler Compressor Assembly (CCA) and Cooler Control Electronics Assembly (CCEA). The design and performance of the test facility to provide a flight representative thermal environment for acceptance testing and characterization of the complete MIRI cooler subsystem are presented.

  9. Cool down time optimization of the Stirling cooler

    Science.gov (United States)

    Xia, M.; Chen, X. P.; Y Li, H.; Gan, Z. H.

    2017-12-01

    The cooling power is one of the most important performances of a Stirling cooler. However, in some special fields, the cool down time is more important. It is a great challenge to improve the cool down time of the Stirling cooler. A new split Stirling linear cryogenic cooler SCI09H was designed in this study. A new structure of linear motor is used in the compressor, and the machine spring is used in the expander. In order to reduce the cool down time, the stainless-steel mesh of regenerator is optimized. The weight of the cooler is 1.1 kg, the cool down time to 80K is 2 minutes at 296K with a 250J thermal mass, the cooling power is 1.1W at 80K, and the input power is 50W.

  10. Variable-speed air-forced cooler technology

    OpenAIRE

    Siffring, Wolfgang

    2016-01-01

    Advanced air coolers are able to cool transformer oil more efficiently than older systems. Replacement or expansion of cooling plants by a new solution can lead to reduction of oil temperatures by several degrees and have a positive influence on the service lifetimes of oil and therefore transformers. Or, conversely, better coolers can – at the same oil temperatures – enhance the maximum performance of a transformer or allow it to operate at a higher average load. The upgrade or expansion of ...

  11. A cryogenic current-measuring device with nano-ampere resolution at the storage ring TARN II

    International Nuclear Information System (INIS)

    Tanabe, T.; Chida, K.; Shinada, K.

    1999-01-01

    In cooler-ring experiments, an accurate and non-destructive current measurement is essential for determining the reaction cross sections. The lowest current which can be measured by the DC current transformer commonly used so far is some μA. In order to measure a low-beam current from nA to μA, we made a cryogenic current-measuring device using a superconducting quantum interference devices (SQUID), and measured the circulating ion current at the cooler ring TARN II. This paper gives the design and performance of the device

  12. Micro-cooler enhancements by barrier interface analysis

    International Nuclear Information System (INIS)

    Stephen, A.; Dunn, G. M.; Glover, J.; Oxley, C. H.; Bajo, M. Montes; Kuball, M.; Cumming, D. R. S.; Khalid, A.

    2014-01-01

    A novel gallium arsenide (GaAs) based micro-cooler design, previously analysed both experimentally and by an analytical Heat Transfer (HT) model, has been simulated using a self-consistent Ensemble Monte Carlo (EMC) model for a more in depth analysis of the thermionic cooling in the device. The best fit to the experimental data was found and was used in conjunction with the HT model to estimate the cooler-contact resistance. The cooling results from EMC indicated that the cooling power of the device is highly dependent on the charge distribution across the leading interface. Alteration of this charge distribution via interface extensions on the nanometre scale has shown to produce significant changes in cooler performance

  13. USE OF PELTIER COOLERS AS SOIL HEAT FLUX TRANSDUCERS.

    Science.gov (United States)

    Weaver, H.L.; Campbell, G.S.

    1985-01-01

    Peltier coolers were modified and calibrated to serve as soil heat flux transducers. The modification was to fill their interiors with epoxy. The average calibration constant on 21 units was 13. 6 plus or minus 0. 8 kW m** minus **2 V** minus **1 at 20 degree C. This sensitivity is about eight times that of the two thermopile transducers with which comparisons were made. The thermal conductivity of the Peltier cooler transducers was 0. 4 W m** minus **1 degree C** minus **1, which is comparable to that of dry soil.

  14. Market Assessment and Commercialization Strategy for the Radial Sandia Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Inc., Burlington, MA (United States); Shandross, Richard [Navigant Consulting, Inc., Burlington, MA (United States); Weintraub, Daniel [Navigant Consulting, Inc., Burlington, MA (United States); Young, Jim [Navigant Consulting, Inc., Burlington, MA (United States)

    2014-02-01

    This market assessment and commercialization report characterizes and assesses the market potential of the rotating heat exchanger technology developed at Sandia National Laboratories (SNL), known as the Radial Sandia Cooler. The RSC is a novel, motor-driven, rotating, finned heat exchanger technology. The RSC was evaluated for the residential, commercial, industrial, and transportation markets. Recommendations for commercialization were made based on assessments of the prototype RSC and the Sandia Cooler technology in general, as well as an in-depth analysis of the six most promising products for initial RSC commercialization.

  15. Transient Air Infiltration/Exfiltration in Walk-In Coolers

    Energy Technology Data Exchange (ETDEWEB)

    Faramarzi, Ramin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Navaz, H. K. [Kettering University; Kamensky, K. [Michigan State University

    2018-03-01

    Walk-in coolers are room-sized, insulated, and refrigerated compartments for food product storage. Walk-ins have areas equal or below 280 m2 (3,000 ft2), and are classified either as coolers operating above 0 degrees C (32 degrees F) (medium-temperature) to store fresh fruit, vegetables, and dairy products, or freezers that operate below 0 degrees C (32 degrees F) (low-temperature) to meet health and safety standards of frozen food products. Walk-ins are typically found in restaurants as well as small- and medium-to-large grocery stores or supermarkets.

  16. Laser pumping of ions in a cooler buncher

    Energy Technology Data Exchange (ETDEWEB)

    Cheal, B., E-mail: bradley.cheal@manchester.ac.uk [University of Manchester (United Kingdom); Baczynska, K. [University of Birmingham, School of Physics and Astronomy (United Kingdom); Billowes, J.; Campbell, P. [University of Manchester (United Kingdom); Eronen, T. [University of Jyvaeskylae, Department of Physics (Finland); Forest, D. H. [University of Birmingham, School of Physics and Astronomy (United Kingdom); Kessler, T.; Moore, I. D. [University of Jyvaeskylae, Department of Physics (Finland); Rueffer, M. [University of Birmingham, School of Physics and Astronomy (United Kingdom); Tordoff, B. [University of Manchester (United Kingdom); Tungate, G. [University of Birmingham, School of Physics and Astronomy (United Kingdom); Aystoe, J. [University of Jyvaeskylae, Department of Physics (Finland)

    2008-01-15

    Optical experiments at the IGISOL isotope separator facility, Jyvaeskylae, have for many years benefited from the introduction of an ion beam cooler. The device, a gas-filled RF quadrupole, reduces the emittance and longitudinal energy spread of the ion beam. Very recently, use has been made of the axial confinement of slowly travelling ions at the end of the cooler to redistribute the electronic populations through efficient laser excitation. Such a technique has proved beneficial to laser spectroscopic measurements and is a precursor to using the method to polarize the ion beam.

  17. Simulations of space charge neutralization in a magnetized electron cooler

    Energy Technology Data Exchange (ETDEWEB)

    Gerity, James [Texas A-M; McIntyre, Peter M. [Texas A-M; Bruhwiler, David Leslie [RadiaSoft, Boulder; Hall, Christopher [RadiaSoft, Boulder; Moens, Vince Jan [Ecole Polytechnique, Lausanne; Park, Chong Shik [Fermilab; Stancari, Giulio [Fermilab

    2017-02-02

    Magnetized electron cooling at relativistic energies and Ampere scale current is essential to achieve the proposed ion luminosities in a future electron-ion collider (EIC). Neutralization of the space charge in such a cooler can significantly increase the magnetized dynamic friction and, hence, the cooling rate. The Warp framework is being used to simulate magnetized electron beam dynamics during and after the build-up of neutralizing ions, via ionization of residual gas in the cooler. The design follows previous experiments at Fermilab as a verification case. We also discuss the relevance to EIC designs.

  18. ring system

    African Journals Online (AJOL)

    1,3,2-DIAZABORACYCLOALKANE. RING SYSTEM. Negussie Retta" and Robert H. Neilson. 'Department of Chemistry, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Department of Chemistry, Texas Christian University.

  19. First turn simulations in the cooler synchrotron COSY

    International Nuclear Information System (INIS)

    Dinev, D.

    1991-07-01

    This paper is devoted to the first turn correction and related problems in particle accelerators of synchrotron type. The paper consists of two parts. The first part is a survey of the existing methods for first turn steering. The second part is entirely devoted to the first turn in the cooler synchrotron COSY which is under assembling in KFA-Julich, Germany. (orig.)

  20. Status of the cooler synchrotron COSY Juelich. Papers

    International Nuclear Information System (INIS)

    1994-09-01

    The eight papers present the status of COSY, operational characteristics of the COSY electron cooler, a broad-band multiple-harmonic acceleration structure, diagnostic tools, a stochastic cooling system, a narrow-band digital RF-noise generator, an RF-synthesizer, and a longitudinal phase space tracking of particles in a multiple harmonic RF-system. (DG)

  1. Sodium flow distribution test of the air cooler tubes

    International Nuclear Information System (INIS)

    Uchida, Hiroyuki; Ohta, Hidehisa; Shimazu, Hisashi

    1980-01-01

    In the heat transfer tubes of the air cooler which is installed in the auxiliary core cooling system of the fast breeder prototype plant reactor ''Monju'', sodium freezing may be caused by undercooling the sodium induced by an extremely unbalanced sodium flow in the tubes. Thus, the sodium flow distribution test of the air cooler tubes was performed to examine the flow distribution of the tubes and to estimate the possibility of sodium freezing in the tubes. This test was performed by using a one fourth air cooler model installed in the water flow test facility. As the test results show, the flow distribution from the inlet header to each tube is almost equal at any operating condition, that is, the velocity deviation from normalized mean velocity is less than 6% and sodium freezing does not occur up to 250% air velocity deviation at stand-by condition. It was clear that the proposed air cooler design for the ''Monju'' will have a good sodium flow distribution at any operating condition. (author)

  2. Commissioning of the LEIR electron cooler with Pb$^{+54}$ ions

    CERN Document Server

    Tranquille, G; Carly, Ch; Prieto, V; Sautier, R; Bubley, A; Parkhomchuk, V; Reva, V; Brizgunov, M; Vedenev, M; Panasyuk, V

    2006-01-01

    The new LEIR cooler with a variable profile of the electron beam and electrostatic bending was commissioned in 2005-2006. In this paper we present our experience with the commissioning of the new device as well as the first results of the ion beam Pb +54 cooling with a high-intensity variable-density electron beam.

  3. Planetary Rings

    Science.gov (United States)

    Nicholson, P. D.

    2001-11-01

    A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

  4. Calculations of air cooler for new subsonic wind tunnel

    Science.gov (United States)

    Rtishcheva, A. S.

    2017-10-01

    As part of the component development of TsAGI’s new subsonic wind tunnel where the air flow velocity in the closed test section is up to 160 m/sec hydraulic and thermal characteristics of air cooler are calculated. The air cooler is one of the most important components due to its highest hydraulic resistance in the whole wind tunnel design. It is important to minimize its hydraulic resistance to ensure the energy efficiency of wind tunnel fans and the cost-cutting of tests. On the other hand the air cooler is to assure the efficient cooling of air flow in such a manner as to maintain the temperature below 40 °C for seamless operation of measuring equipment. Therefore the relevance of this project is driven by the need to develop the air cooler that would demonstrate low hydraulic resistance of air and high thermal effectiveness of heat exchanging surfaces; insofar as the cooling section must be given up per unit time with the amount of heat Q=30 MW according to preliminary evaluations. On basis of calculation research some variants of air cooler designs are proposed including elliptical tubes, round tubes, and lateral plate-like fins. These designs differ by the number of tubes and plates, geometrical characteristics and the material of finned surfaces (aluminium or cooper). Due to the choice of component configurations a high thermal effectiveness is achieved for finned surfaces. The obtained results form the basis of R&D support in designing the new subsonic wind tunnel.

  5. Dielectronic recombination experiments at the storage rings: From the present CSR to the future HIAF

    Science.gov (United States)

    Huang, Z. K.; Wen, W. Q.; Xu, X.; Wang, H. B.; Dou, L. J.; Chuai, X. Y.; Zhu, X. L.; Zhao, D. M.; Li, J.; Ma, X. M.; Mao, L. J.; Yang, J. C.; Yuan, Y. J.; Xu, W. Q.; Xie, L. Y.; Xu, T. H.; Yao, K.; Dong, C. Z.; Zhu, L. F.; Ma, X.

    2017-10-01

    Dielectronic recombination (DR) experiments of highly charged ions at the storage rings have been developed as a precision spectroscopic tool to investigate the atomic structure as well as nuclear properties of stable and unstable nuclei. The DR experiment on lithium-like argon ions was successfully performed at main Cooler Storage Ring (CSRm) at Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex. The DR experiments on heavy highly charged ions and even radioactive ions are currently under preparation at the experimental Cooler Storage Ring (CSRe) at HIRFL. The current status of DR experiments at the CSRm and the preparation of the DR experiments at the CSRe are presented. In addition, an overview of DR experiments by employing an electron cooler and a separated ultra-cold electron target at the upcoming High Intensity heavy ion Accelerator Facility (HIAF) will be given.

  6. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams

  7. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  8. Ring accelerators

    International Nuclear Information System (INIS)

    Gisler, G.; Faehl, R.

    1983-01-01

    We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

  9. An implantable nerve cooler for the exercising dog.

    Science.gov (United States)

    Borgdorff, P; Versteeg, P G

    1984-01-01

    An implantable nerve cooler has been constructed to block cervical vago-sympathetic activity in the exercising dog reversibly. An insulated gilt brass container implanted around the nerve is perfused with cooled alcohol via silicone tubes. The flow of alcohol is controlled by an electromagnetic valve to keep nerve temperature at the required value. Nerve temperature is measured by a thermistor attached to the housing and in contact with the nerve. It is shown that, during cooling, temperature at this location differs less than 2 degrees C from nerve core temperature. Measurement of changes in heart rate revealed that complete vagal block in the conscious animal is obtained at a nerve temperature of 2 degrees C and can be achieved within 50 s. During steady-state cooling in the exercising animal nerve temperature varied less than 0.5 degree C. When the coolers after 2 weeks of implantation were removed they showed no oxydation and could be used again.

  10. Thermoelectric cooler concepts and the limit for maximum cooling

    International Nuclear Information System (INIS)

    Seifert, W; Hinsche, N F; Pluschke, V

    2014-01-01

    The conventional analysis of a Peltier cooler approximates the material properties as independent of temperature using a constant properties model (CPM). Alternative concepts have been published by Bian and Shakouri (2006 Appl. Phys. Lett. 89 212101), Bian (et al 2007 Phys. Rev. B 75 245208) and Snyder et al (2012 Phys. Rev. B 86 045202). While Snyder's Thomson cooler concept results from a consideration of compatibility, the method of Bian et al focuses on the redistribution of heat. Thus, both approaches are based on different principles. In this paper we compare the new concepts to CPM and we reconsider the limit for maximum cooling. The results provide a new perspective on maximum cooling. (paper)

  11. Advances in a high efficiency commercial pulse tube cooler

    Science.gov (United States)

    Zhang, Yibing; Li, Haibing; Wang, Xiaotao; Dai, Wei; Yang, Zhaohui; Luo, Ercang

    2017-12-01

    The pulse tube cryocooler has the advantage of no moving part at the cold end and offers a high reliability. To further extend its use in commercial applications, efforts are still needed to improve efficiency, reliability and cost effectiveness. This paper generalizes several key innovations in our newest cooler. The cooler consists of a moving magnet compressor with dual-opposed pistons, and a co-axial cold finger. Ambient displacers are employed to recover the expansion work to increase cooling efficiency. Inside the cold finger, the conventional flow straightener screens are replaced by a tapered throat between the cold heat exchanger and the pulse tube to strengthen its immunity to the working gas contamination as well as to simplify the manufacturing processes. The cold heat exchanger is made by copper forging process which further reduces the cost. Inside the compressor, a new gas bearing design has brought in assembling simplicity and running reliability. Besides the cooler itself, electronic controller is also important for actual application. A dual channel and dual driving mode control mechanism has been selected, which reduces the vibration to a minimum, meanwhile the cool-down speed becomes faster and run-time efficiency is higher. With these innovations, the cooler TC4189 reached a no-load temperature of 44 K and provided 15 W cooling power at 80K, with an input electric power of 244 W and a cooling water temperature of 23 ℃. The efficiency reached 16.9% of Carnot at 80 K. The whole system has a total mass of 4.3 kg.

  12. Numerical simulation of a semi-indirect evaporative cooler

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R. Herrero [Departamento de Ingenieria Termica y de Fluidos, Universidad Politecnica de Cartagena, C/Dr. Fleming, s/n (Campus Muralla), 30202 Cartagena, Murcia (Spain)

    2009-11-15

    This paper presents the experimental study and numerical simulation of a semi-indirect evaporative cooler (SIEC), which acts as an energy recovery device in air conditioning systems. The numerical simulation was conducted by applying the CFD software FLUENT implementing a UDF to model evaporation/condensation. The numerical model was validated by comparing the simulation results with experimental data. Experimental data and numerical results agree for the lower relative humidity series but not for higher relative humidity values. (author)

  13. Linear motor driven Stirling coolers for military and commercial applications

    International Nuclear Information System (INIS)

    Berry, R.

    1992-01-01

    This paper discusses the design and performance of a miniature, closed cycle, split stirling, cryogenic cooler that provides 1 watt of cooling at 80 K. The compressor uses two opposed linear motors to drive opposed pistons and the expander uses a pneumatically driven displacer. A single electronics module and compressor has been developed to drive three different expanders that have nominal cold cylinder diameters of 5, 8 and 13 mm

  14. Experimental testing of the thermal performance of finned air coolers

    International Nuclear Information System (INIS)

    Imhof, A.; Keller, J.; Koelliker, A.

    1988-05-01

    Finned heat exchangers are often used as regenerators in heat recovery systems or as a heat source for heat pump installations. These exchangers are usually operating as air coolers. Heat is extracted from the air flowing through the heat exchanger. If the fin temperature lies below the dew point at the air inlet, water vapour may be condensed, increasing the thermal performance of the cooler. If the air/water heat exchanger is installed outdoors, the blower is usually mounted directly at the exchaner's case. In general this leads to non-ideal air flow conditions. For the sizing of such components the manufacturers dispose of design rules which are based either on theoretical models or on experiments using a uniform air stream. These rules which are mostly internal codes of the individual companies presumably do not take into account some non-ideal conditions such as an inhomogeneous air flow, a poorly sized blower or an increased pressure drop between the fins due to condensed water vapour. Moreover, these codes are possibly not sophisticated enough to enable a correct sizing of the products for any given condition of operation, especially in heat pumps operating under condensation conditions. Therfore, the Swiss Federal Institute for Reactor Research (EIR) carried out a research program dealing with the thermal performance of commercially available finned air coolers. The results give a strong evidence that the sizing of finned air coolers involving a phase change in one of the heat transfer fluids is not yet a procedure belonging to the common knowledge of most of the manufacturers. Moreover, the correct sizing of the blower is at least as important as the sizing of the finned exchanger itself. However, it is evident that there are companies on the Swiss market which use already reliable design tools. 25 refs., 81 figs., 12 tabs

  15. Comparative analysis of linear motor geometries for Stirling coolers

    Science.gov (United States)

    R, Rajesh V.; Kuzhiveli, Biju T.

    2017-12-01

    Compared to rotary motor driven Stirling coolers, linear motor coolers are characterized by small volume and long life, making them more suitable for space and military applications. The motor design and operational characteristics have a direct effect on the operation of the cooler. In this perspective, ample scope exists in understanding the behavioural description of linear motor systems. In the present work, the authors compare and analyze different moving magnet linear motor geometries to finalize the most favourable one for Stirling coolers. The required axial force in the linear motors is generated by the interaction of magnetic fields of a current carrying coil and that of a permanent magnet. The compact size, commercial availability of permanent magnets and low weight requirement of the system are quite a few constraints for the design. The finite element analysis performed using Maxwell software serves as the basic tool to analyze the magnet movement, flux distribution in the air gap and the magnetic saturation levels on the core. A number of material combinations are investigated for core before finalizing the design. The effect of varying the core geometry on the flux produced in the air gap is also analyzed. The electromagnetic analysis of the motor indicates that the permanent magnet height ought to be taken in such a way that it is under the influence of electromagnetic field of current carrying coil as well as the outer core in the balanced position. This is necessary so that sufficient amount of thrust force is developed by efficient utilisation of the air gap flux density. Also, the outer core ends need to be designed to facilitate enough room for the magnet movement under the operating conditions.

  16. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  17. Fan Cooler Operation in Kori 1 for Mitigating Severe Accident

    International Nuclear Information System (INIS)

    Suh, Nam Duk; Park, Jae Hong

    2005-01-01

    The Korea Ministry of Science and Technology (MOST) issued the 'Policy on Severe Accident of Nuclear Power Plants' in August 2001. According to the policy it was required for the licensee to develop a plant specific severe accident management guideline (SAMG) and to implement it. Thus the utility has made an implementation plan to develop SAMGs for operating plants. The SAMG for Kori unit 1 was submitted to the government on January 2004. Since then, the government trusted KINS to review the submitted SAMG in view of its feasibility and effectiveness. The first principle of the developed SAMG is to use only the available facilities as it is without introducing any system change. Because Kori-1 has no mitigative facility against combustible gases during severe accident, it relies heavily both on spray and on fan cooler systems to control the containment condition. Thus one of the issues raised during the review is to know whether the fan coolers which are designed for DBA LOCA can be effective in mitigating the severe accident conditions. This paper presents an analysis result of fan cooler operation in controlling the containment condition during severe accident of Kori 1

  18. CFD study of a simple orifice pulse tube cooler

    Science.gov (United States)

    Zhang, X. B.; Qiu, L. M.; Gan, Z. H.; He, Y. L.

    2007-05-01

    Pulse tube cooler (PTC) has the advantages of long-life and low vibration over the conventional cryocoolers, such as G-M and Stirling coolers because of the absence of moving parts in low temperature. This paper performs a two-dimensional axis-symmetric computational fluid dynamic (CFD) simulation of a GM-type simple orifice PTC (OPTC). The detailed modeling process and the general results such as the phase difference between velocity and pressure at cold end, the temperature profiles along the wall as well as the temperature oscillations at cold end with different heat loads are presented. Emphases are put on analyzing the complicated phenomena of multi-dimensional flow and heat transfer in the pulse tube under conditions of oscillating pressure. Swirling flow pattern in the pulse tube is observed and the mechanism of formation is analyzed in details, which is further validated by modeling a basic PTC. The swirl causes undesirable mixing in the thermally stratified fluid and is partially responsible for the poor overall performance of the cooler, such as unsteady cold-end temperature.

  19. Thermodynamic comparison of Peltier, Stirling, and vapor compression portable coolers

    International Nuclear Information System (INIS)

    Hermes, Christian J.L.; Barbosa, Jader R.

    2012-01-01

    Highlights: ► A Peltier, a Stirling, and two vapor compression refrigerators were compared. ► Tests were carried out to obtain key performance parameters of the systems. ► The overall 2nd-law efficiency was splited to take into account the internal and external irreversibilities. ► The Stirling and vapor compression refrigeration systems presented higher efficiencies. ► The thermoelectric device was not at the same efficiency level as the other coolers. -- Abstract: The present study compares the thermodynamic performance of four small-capacity portable coolers that employ different cooling technologies: thermoelectric, Stirling, and vapor compression using two different compressors (reciprocating and linear). The refrigeration systems were experimentally evaluated in a climatized chamber with controlled temperature and humidity. Tests were carried out at two different ambient temperatures (21 and 32 °C) in order to obtain key performance parameters of the systems (e.g., power consumption, cooling capacity, internal air temperature, and the hot end and cold end temperatures). These performance parameters were compared using a thermodynamic approach that splits the overall 2nd law efficiency into two terms, namely, the internal and external efficiencies. In doing so, the internal irreversibilities (e.g., friction in the working fluid in the Stirling and vapor compression machines, Joule heating and heat conduction in the thermoelectric devices of the Peltier cooler) were separated from the heat exchanger losses (external irreversibilities), allowing the comparison between different refrigeration technologies with respect to the same thermodynamic baseline.

  20. Six Sigma methods applied to cryogenic coolers assembly line

    Science.gov (United States)

    Ventre, Jean-Marc; Germain-Lacour, Michel; Martin, Jean-Yves; Cauquil, Jean-Marc; Benschop, Tonny; Griot, René

    2009-05-01

    Six Sigma method have been applied to manufacturing process of a rotary Stirling cooler: RM2. Name of the project is NoVa as main goal of the Six Sigma approach is to reduce variability (No Variability). Project has been based on the DMAIC guideline following five stages: Define, Measure, Analyse, Improve, Control. Objective has been set on the rate of coolers succeeding performance at first attempt with a goal value of 95%. A team has been gathered involving people and skills acting on the RM2 manufacturing line. Measurement System Analysis (MSA) has been applied to test bench and results after R&R gage show that measurement is one of the root cause for variability in RM2 process. Two more root causes have been identified by the team after process mapping analysis: regenerator filling factor and cleaning procedure. Causes for measurement variability have been identified and eradicated as shown by new results from R&R gage. Experimental results show that regenerator filling factor impacts process variability and affects yield. Improved process haven been set after new calibration process for test bench, new filling procedure for regenerator and an additional cleaning stage have been implemented. The objective for 95% coolers succeeding performance test at first attempt has been reached and kept for a significant period. RM2 manufacturing process is now managed according to Statistical Process Control based on control charts. Improvement in process capability have enabled introduction of sample testing procedure before delivery.

  1. Conversion of St. Marys conventional grate cooler at the Bowmanville plant

    Energy Technology Data Exchange (ETDEWEB)

    Keefe, B.P. (Fuller Co., Bethlehem, PA (United States))

    1993-11-01

    Fuller Company has recently retrofitted the largest operating clinker cooler in North America with its CFG (Controlled Flow Grate) system. The cooler conversion was made to the St. Mary's Cement's 5000 mtpd Folax grate cooler at the Bowmanville plant. The project included conversion of the entire first drive section to Fuller's new cooler design featuring its increased flow resistance grate plates, a maintenance-friendly air distribution system, and a new hydraulic drive unit. As a result of the cooler conversion, significant power and fuel savings were made possible for an already efficient and modern cement producing facility. (author)

  2. Consideration of heat transfer performance of helium-gas/water coolers in HENDEL

    International Nuclear Information System (INIS)

    Inagaki, Yoshiyuki; Miyamoto, Yoshiaki

    1986-10-01

    The helium engineering loop (HENDEL) has four helium-gas/water coolers, where the cooling water flows in the tubes and the helium gas flows on the shell side. Their cooling performance depends on mainly the heat transfer of helium gas on the shell side. This report describes the operational data of the coolers and the consideration of the heat transfer performance which is important for the design of coolers. It becomes clear that Donohue's equation is close to the operational data and conservative for the segmental baffle type cooler and preduction by Fishenden-Saunders or Zukauskas' equation is conservation for the step-up baffle type cooler. (author)

  3. COOL DUST IN THE OUTER RING OF NGC 1291

    International Nuclear Information System (INIS)

    Hinz, J. L.; Engelbracht, C. W.; Skibba, R.; Montiel, E.; Crocker, A.; Calzetti, D.; Donovan Meyer, J.; Sandstrom, K.; Walter, F.; Groves, B.; Meidt, S. E.; Johnson, B. D.; Hunt, L.; Aniano, G.; Draine, B.; Murphy, E. J.; Armus, L.; Dale, D. A.; Galametz, M.; Kennicutt, R. C.

    2012-01-01

    We examine Herschel Space Observatory images of one nearby prototypical outer ring galaxy, NGC 1291, and show that the ring becomes more prominent at wavelengths longer than 160 μm. The mass of cool dust in the ring dominates the total dust mass of the galaxy, accounting for at least 70% of it. The temperature of the emitting dust in the ring (T = 19.5 ± 0.3 K) is cooler than that of the inner galaxy (T = 25.7 ± 0.7 K). We discuss several explanations for the difference in dust temperature, including age and density differences in the stellar populations of the ring versus the bulge.

  4. Dry coolers and air-condensing units (Review)

    Science.gov (United States)

    Milman, O. O.; Anan'ev, P. A.

    2016-03-01

    The analysis of factors affecting the growth of shortage of freshwater is performed. The state and dynamics of the global market of dry coolers used at electric power plants are investigated. Substantial increase in number and maximum capacity of air-cooled condensers, which have been put into operation in the world in recent years, are noted. The key reasons facilitating the choice of developers of the dry coolers, in particular the independence of the location of thermal power plant from water sources, are enumerated. The main steam turbine heat removal schemes using air cooling are considered, their comparison of thermal efficiency is assessed, and the change of three important parameters, such as surface area of heat transfer, condensate pump flow, and pressure losses in the steam exhaust system, are estimated. It is shown that the most effective is the scheme of direct steam condensation in the heat-exchange tubes, but other schemes also have certain advantages. The air-cooling efficiency may be enhanced much more by using an air-cooling hybrid system: a combination of dry and wet cooling. The basic applied constructive solutions are shown: the arrangement of heat-exchange modules and the types of fans. The optimal mounting design of a fully shopassembled cooling system for heat-exchange modules is represented. Different types of heat-exchange tubes ribbing that take into account the operational features of cooling systems are shown. Heat transfer coefficients of the plants from different manufacturers are compared, and the main reasons for its decline are named. When using evaporative air cooling, it is possible to improve the efficiency of air-cooling units. The factors affecting the faultless performance of dry coolers (DC) and air-condensing units (ACU) and the ways of their elimination are described. A high velocity wind forcing reduces the efficiency of cooling systems and creates preconditions for the development of wind-driven devices. It is noted that

  5. The Optimum Selection and Drawing Output Program Development of Shell and Tube Type Oil Cooler

    International Nuclear Information System (INIS)

    Lee, Y. B.; Kim, T. S.; Ko, J. M

    2007-01-01

    Shell and Tube type Oil Cooler is widely used for hydraulic presses, die casting machines, generation equipments, machine tools and construction heavy machinery. Temperature of oil in the hydraulic system changes viscosity and thickness of oil film. They have a bad effect to performance and lubrication of hydraulic machinery, so it is important to know exactly the heat exchanging efficiency of oil cooler for controlling oil temperature. But most Korean manufacturers do not have test equipment for oil cooler, so they cannot carry out the efficiency test of oil cooler and it is impossible to verify its performance. This paper includes information of construction of necessary utilities for oil cooler test and design and manufacture of test equipment. One can select the optimum product by obtaining performance data through tests of various kinds of oil coolers. And also the paper developed a program which can be easily used for design of 2D and 3D drawings of oil cooler

  6. Experimental study of a high intensity radio-frequency cooler

    Directory of Open Access Journals (Sweden)

    Ramzi Boussaid

    2015-07-01

    Full Text Available Within the framework of the DESIR/SPIRAL-2 project, a radio-frequency quadrupole cooler named SHIRaC has been studied. SHIRaC is a key device of SPIRAL-2, designed to enhance the beam quality required by DESIR. The preliminary study and development of this device has been carried out at Laboratoire de Physique Corpusculaire de CAEN (LPC Caen, France. The goal of this paper is to present the experimental studies conducted on a SHIRaC prototype. The main peculiarity of this cooler is its efficient handling and cooling of ion beams with currents going up as high as 1  μA which has never before been achieved in any of the previous coolers. Much effort has been made lately into these studies for development of appropriate optics, vacuum and rf systems which allow cooling of beams of large emittance (∼80π  mm mrad and high current. The dependencies of SHIRaC’s transmission and the cooled beam parameters in terms of geometrical transverse emittance and the longitudinal energy spread have also been discussed. Investigation of beam purity at optimum cooling condition has also been done. Results from the experiments indicate that an emittance reduction of less than 2.5π  mm mrad and a longitudinal energy spread reduction of less than 4 eV are obtained with more than 70% of ion transmission. The emittance is at expected values whereas the energy spread is not.

  7. Gasket structure improvement for the spent fuel pool cooler

    International Nuclear Information System (INIS)

    Li Yun; He Shaohua; Qi Hongchang; Wang Cong; Wang Chenglin; Zhong Boling

    2014-01-01

    The two spent fuel pool coolers for the 320 MW unit in CNNC Nuclear Power Operation Management Co., Ltd. have operated for more than 20 years. In accordance with the preventive maintenance programs, they must be overhauled. It is decided to improve the original gasket structure of the component and adopt the method of a short-length U-tubes pulling after analysis and study. There are no leakages and other abnormal situations after the equipment being put into operation. The unit is kept safe and stable. At the same time, thought and method for the maintenance of other similar equipment are provided. (authors)

  8. Laser spectroscopy of gallium isotopes using the ISCOOL RFQ cooler

    CERN Multimedia

    Blaum, K; Kowalska, M; Ware, T; Procter, T J

    2007-01-01

    We propose to study the radioisotopes of gallium (Z=31) by collinear laser spectroscopy using the ISCOOL RFQ ion cooler. The proposed measurements on $^{62-83}$Ga will span both neutron-deficient and neutron-rich isotopes. Of key interest is the suggested development of a proton-skin in the neutron-deficient isotopes. The isotope shifts measured by laser spectroscopy will be uniquely sensitive to this feature. The measurements will also provide a wealth of new information on the gallium nuclear spins, static moments and nuclear charge radii.

  9. Integral finned heater and cooler for stirling engines

    Science.gov (United States)

    Corey, John A.

    1984-01-01

    A piston and cylinder for a Stirling engine and the like having top and bottom meshing or nesting finned conical surfaces to provide large surface areas in close proximity to the working gas for good thermal (addition and subtraction of heat) exchange to the working gas and elimination of the usual heater and cooler dead volume. The piston fins at the hot end of the cylinder are perforated to permit the gas to pass into the piston interior and through a regenerator contained therein.

  10. Study of beam dynamics at cooler synchrotron TARN-II

    International Nuclear Information System (INIS)

    Watanabe, S.; Katayama, T.; Watanabe, T.; Yoshizawa, M.; Tomizawa, M.; Chida, K.; Arakaki, Y.; Noda, K.; Kanazawa, M.

    1992-08-01

    Several kinds of beam diagnostic instruments, have been developed at cooler-synchrotron TARN-II. These are intended to study beam dynamics at low beam current of several microamperes and then have high sensitivity of good S/N ratio. In addition, the acceleration system, especially low level RF system, has been improved to attain the maximum beam energy. With the successful performance of these instrumentations, the study of beam dynamics are presently being carried out. For example, the synchrotron acceleration of the light ions was achieved up to 220 MeV/u without any beam loss. (author)

  11. Note: Wide-operating-range control for thermoelectric coolers

    Science.gov (United States)

    Peronio, P.; Labanca, I.; Ghioni, M.; Rech, I.

    2017-11-01

    A new algorithm for controlling the temperature of a thermoelectric cooler is proposed. Unlike a classic proportional-integral-derivative (PID) control, which computes the bias voltage from the temperature error, the proposed algorithm exploits the linear relation that exists between the cold side's temperature and the amount of heat that is removed per unit time. Since this control is based on an existing linear relation, it is insensitive to changes in the operating point that are instead crucial in classic PID control of a non-linear system.

  12. Electron gun design for HIRFL-CSR electron cooler

    International Nuclear Information System (INIS)

    Rao Yinong; Xia Jiawen; Yuan Youjin; Wei Baowen

    1996-01-01

    Adiabatic acceleration is employed to design the electron gun of HIRFL-CSR e-cooler by using the modified EGUN code. The electron beam transverse temperature variations with anode region and acceleration tube design parameters as well as the uniform solenoidal magnetic field are presented. Transversal temperature of less than 0.1 eV at a maximum current density of 0.244 A/cm 2 are obtained over the full energy range of 2.75∼165 keV

  13. Development of a small Stirling-cycle cooler for spaceflight applications

    Energy Technology Data Exchange (ETDEWEB)

    Werrett, S.T.; Peskett, G.D.; Davey, G.; Bradshaw, T.W.; Delderfield, J.

    1985-01-01

    The paper describes the development, from a previously proven design approach, of a robust and simple Stirling-cycle cooler with long-life potential. The need for a closed-cycle refrigerator for use in a spacecraft borne infrared radiometer is explained. The refrigerator is to supply 1 watt of cooling at 80 K for less than 80 watts of input power, be able to survive the launch environment and subsequently run for 26000 hours. Clearance seals achieved with a spring suspension developed from earlier space-proven mechanisms have led to the production of a linear split Stirling-cycle machine with no apparent life limiting features. A servo-control system, in conjunction with moving coil motors and LVDT position sensors, permits running of balanced pairs of mechanisms. The working fluid, helium at a pressure of 1.2 MPa, is contained within titanium bodies having gold O-ring seals. A vacuum-bakeout procedure, based upon experience and outgassing trials, reduces residual contaminant release to acceptable levels. A prototype refrigerator was subjected to a vibration test and has subsequently run for 6000 hours with no detectable change in performance.

  14. Developments for the HITRAP cooler trap and mass measurements around A = 96 at SHIPTRAP

    International Nuclear Information System (INIS)

    Koszudowski, Stephen

    2009-01-01

    The HITRAP (Highly charged Ions Trap) facility is currently being set up and commissioned at GSI in Darmstadt. It will provide bunches of 10 5 heavy highly-charged ions, for example hydrogen-like uranium (U 91+ ), to high-precision atomic physics experiments. The ions are produced by the GSI accelerator complex and decelerated to 4 MeV/u in the Experimental Storage Ring. Then the ions are decelerated by a two-step linear decelerator down to 6 keV/u. The first deceleration step down to 500 keV/u was successfully commissioned. The decelerated ions are injected into a Penning trap (the Cooler Trap), where they are cooled to 4 K by electron and resistive cooling. Resonant circuits for non-destructive detection and the resistive cooling of the trapped particles were designed and tested. The time control of the trap-cycle (trapping, cooling, extraction) with a time resolution of 25 ns was implemented into the control system CS. CS is also used at the mass measurement Penning trap SHIPTRAP, where the new time control is successfully operated. SHIPTRAP measures radioactive ions stemming from fusion evaporation reactions at the velocity filter SHIP. The masses of 9 nuclides ( 93,94,95 Technetium, 94,96 Ruthenium, 95,96,97,98 Rhodium) near the line of stability were precisely measured and compared with the Atomic Mass Evaluation. The detection of isomeric states with the present SHIPTRAP set-up was studied. (orig.)

  15. Solar-Powered Cooler and Heater for an Automobile Interior

    Science.gov (United States)

    Howard, Richard T.

    2006-01-01

    The apparatus would include a solar photovoltaic panel mounted on the roof and a panellike assembly mounted in a window opening. The window-mounted assembly would include a stack of thermoelectric devices sandwiched between two heat sinks. A fan would circulate interior air over one heat sink. Another fan would circulate exterior air over the other heat sink. The fans and the thermoelectric devices would be powered by the solar photovoltaic panel. By means of a double-pole, double-throw switch, the panel voltage fed to the thermoelectric stack would be set to the desired polarity: For cooling operation, the chosen polarity would be one in which the thermoelectric devices transport heat from the inside heat sink to the outside one; for heating operation, the opposite polarity would be chosen. Because thermoelectric devices are more efficient in heating than in cooling, this apparatus would be more effective as a heater than as a cooler. However, if the apparatus were to include means to circulate air between the outside and the inside without opening the windows, then its effectiveness as a cooler in a hot, sunny location would be increased.

  16. Design and performance of an RFQ cooler and buncher

    Energy Technology Data Exchange (ETDEWEB)

    Szerypo, J.; Ban, G.; Le Brun, C.; Delahaye, P.; Lienard, E.; Mauger, F.; Naviliat, O.; Tamain, B. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Hennecart, D. [Centre Interdisciplinaire de Recherche Ions Lasers, 14 - Caen (France)

    1999-10-01

    Several new experiments, planned or in preparation at low energy radioactive beam facilities, require the cooling and bunching of radioactive beams. This may be performed with a radiofrequency quadruple (RFQ) cooler and buncher, where the ions are cooled in a buffer gas while being guided by an oscillating RFQ field. This work describes the performance of such a device, which has been designed and studied in order to be extended for the cooling of light ions. The analysis requires extensive computer simulations, which are done with two approaches: the macroscopic and the microscopic. The latter approach is able to account for the RF-heating effect and the calculations were performed by the monte Carlo method. The cooling formalism was extendedto include a charge-exchange effect. The charge-exchange cross sections were calculated theoretically in a quantum-mechanical formalism for different ion-atom combinations. The simulations have shown in particular that for the cooling of {sup 6}He{sup +} ions, {sup 4}He is excluded as buffer gas because of the resonant charge exchange processes which drastically decreases the transmission. On the other hand, the cooling of {sup 6}He{sup +} ions with H{sub 2} as buffer gas appears as a promising solution. The most relevant cooler design parameters are proposed. A project of a complete system, including the deceleration, extraction and transfer sections, is presented. (authors)

  17. RFQ Cooler and Buncher (and beam line section associated)

    CERN Document Server

    Podadera-Aliseda, I

    2003-01-01

    Developing a new RFQ cooler and buncher for ISOLDE. Such a device combines an energy loss in buffer gas atom-ion collisions with confinement provided by RF-field in transverse plane. Optional confinement in longitudinal direction is provided by static potential dwell. Then, an improvement of the beam line is achieved for all the experiments at ISOLDE. The RFQ operates inside a high voltage cage of 60 kV, and with a system of turbomulecular pumps both to keep the high vacuum before/after the RFQ and to keep a low pressure (around 0,1 mbar) inside the RFQ. The project is to be thought not only as a mechanical design and construction project, unless as a project of research and development, since it is about improving (operationally and technically) the existing RFQ cooler and buncher placed around the world. Due to ion optical reasons whole beam line section has to be redesigned and constructed as a part of this project.

  18. Study of containment air cooler capacity in steam air environment during accident conditions

    International Nuclear Information System (INIS)

    Kansal, M.; Mohan, N.; Bhawal, R.N.; Bajaj, S.S.

    2002-01-01

    Full text: The air coolers are provided for controlling the temperature in the reactor building during normal operation. These air coolers also serve as the main heat sink for the removal of energy from high enthalpy air-steam mixture expected in reactor building under accident conditions. A subroutine COOLER has been developed to estimate the heat removal rate of the air coolers at high temperature and steam conditions. The subroutine COOLER has been attached with the code PACSR (post accident containment system response) used for containment pressure temperature calculation. The subroutine was validated using design parameters at normal operating condition. A study was done to estimate the heat removal rate for some postulated accident conditions. The study reveals that, under accident conditions, the heat removal rate of air coolers increases several times compared with normal operating conditions

  19. Design and measured performance of a porous evaporative cooler for preservation of fruits and vegetables

    International Nuclear Information System (INIS)

    Anyanwu, E.E.

    2004-01-01

    The design, construction and measured performance of a porous evaporative cooler for preservation of fruits and vegetables are reported. The experimental cooler, with a total storage space of 0.014 m 3 , consists of a cuboid shaped porous clay container located inside another clay container. The gap between them is filled with coconut fibre. A water reservoir linked to the cooler at the top through a flexible pipe supplied water to fill the gap, thus keeping the coconut fibre continuously wet. Results of the transient performance tests revealed that the cooler storage chamber temperature depression from ambient air temperature varied over 0.1-12 deg. C. Ambient air temperatures during the test periods ranged over 22-38 deg. C. The results also illustrate superior performance of the cooler over open air preservation of vegetables soon after harvest during the diurnal operations. Thus, the evaporative cooler has prospects for use for short term preservation of vegetables and fruits soon after harvest

  20. Investigation of the vibration and EMC characteristics of miniature Stirling electric coolers for space applications

    Science.gov (United States)

    Kondratjev, V.; Gostilo, V.; Owens, anb A.

    2017-08-01

    We present the results of an investigation into the detrimental effects that electromechanical coolers can have on the spectral performance of compact, large volume HPGe spectrometers for space applications. Both mechanical vibration and electromagnetic pickup effects were considered, as well as a comparative assessment between three miniature Stirling cycle coolers—two Ricor model K508 coolers and one Thales model RM3 cooler. In spite of the limited number of coolers tested, the following conclusions can be made. There are significant differences in the vibration characteristics not only between the various types of cooler but also between coolers of the same type. It was also found that compared to the noise induced by mechanical vibrations, electromagnetic interference emanating from the embedded controllers does not significantly impact the energy resolution of detectors.

  1. Direct Evaporatrive Coolers of Gases and Liquids with Lowered Limit of Cooling

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2015-12-01

    Full Text Available We have developed main technical solutions solution of indirect evaporative water and air coolers with reduced cooling limit. Packed part of heat-mass transfer devices is made of the film type based monoblock compositions of polymer materials. A mathematical model describing the processes of joint heat and mass transfer in evaporative coolers is executed. A comparative analysis of the possibilities of coolers designed based on experimental data on the efficiency of processes of heat and mass transfer.

  2. The making of automation air fiddling unit (AHU) for G 71 cooler system

    International Nuclear Information System (INIS)

    Suripto

    2003-01-01

    A design of the making automation of air handling unit (AHU) for G. 71 cooler system at the design it has been conducted AHU operational time programming for G. 71 cooler system, when applied if will operate as programmed. flopefully, it mill save electric power and the dependency to the operator can be reduced significantly therefore it will increase efficiency and optimization in the usage of the cooler system. At the and if will reduce and save operational cost mainly in maintenance cost

  3. Evaporative Air Coolers Optimization for Energy Consumption Reduction and Energy Efficiency Ratio Increment

    OpenAIRE

    Leila Torkaman; Nasser Ghassembaglou

    2015-01-01

    Significant quota of Municipal Electrical Energy consumption is related to Decentralized Air Conditioning which is mostly provided by evaporative coolers. So the aim is to optimize design of air conditioners to increase their efficiencies. To achieve this goal, results of practical standardized tests for 40 evaporative coolers in different types collected and simultaneously results for same coolers based on one of EER (Energy Efficiency Ratio) modeling styles are figured ...

  4. Performance of an irreversible quantum Ericsson cooler at low temperature limit

    International Nuclear Information System (INIS)

    Wu Feng; Chen Lingen; Wu Shuang; Sun Fengrui

    2006-01-01

    The purpose of this paper is to investigate the effect of quantum properties of the working medium on the performance of an irreversible quantum Ericsson cooler with spin-1/2. The cooler is studied with the losses of heat resistance, heat leakage and internal irreversibility. The optimal relationship between the dimensionless cooling load R * versus the coefficient of performance ε for the irreversible quantum Ericsson cooler is derived. In particular, the performance characteristics of the cooler at the low temperature limit are discussed

  5. Technical assistance for the evaluation of fluid loop components (Peltier cooler)

    Science.gov (United States)

    Best, R.; Biemann, W.; Bosch, R.; Hingst, U.; Kreeb, H.; Mueller, W.

    1980-07-01

    The application of Peltier elements for refrigeration with source temperature control and heat rejection to a fluid loop was investigated using commercially available Peltier cooling elements. Peltier element performance with Peltier elements integrated into a cooler unit, investigation of possible temperature stabilization of the source side of the Peltier cooler arrangement, investigation of the necessary power supply and the power consumption for certain requirements for temperature range and heat load at the source, and investigation of mounting and integration aspects are discussed. Analytical calculations for the performance of Peltier elements in a cooler unit are relevant for a power supply, a temperature regulation system, and the design of bread board cooler unit.

  6. SAFARI engineering model 50 mK cooler

    Science.gov (United States)

    Duband, L.; Duval, J. M.; Luchier, N.

    2014-11-01

    SAFARI is an infrared instrument developed by a European based consortium to be flown in SPICA, a Japanese led mission. The SAFARI detectors are transition edge sensors (TES) and require temperatures down to 50 mK for their operation. For that purpose we have developed a hybrid architecture based on the combination of a 300 mK sorption stage and a small adiabatic demagnetization stage. An engineering model has been designed to provide net heat lifts of 0.4 and 14 μW respectively at 50 and 300 mK, with an overall cycle duration of 48 h and a duty cycle objective of over 75%. The cooler is self-contained, fits in a volume of 156 × 312 × 182 mm and is expected to weigh 5.1 kg. It has been designed to withstand static loads of 120 g and a random vibration level of 21 g RMS.

  7. Geometric Optimization of Thermo-electric Coolers Using Simulated Annealing

    International Nuclear Information System (INIS)

    Khanh, D V K; Vasant, P M; Elamvazuthi, I; Dieu, V N

    2015-01-01

    The field of thermo-electric coolers (TECs) has grown drastically in recent years. In an extreme environment as thermal energy and gas drilling operations, TEC is an effective cooling mechanism for instrument. However, limitations such as the relatively low energy conversion efficiency and ability to dissipate only a limited amount of heat flux may seriously damage the lifetime and performance of the instrument. Until now, many researches were conducted to expand the efficiency of TECs. The material parameters are the most significant, but they are restricted by currently available materials and module fabricating technologies. Therefore, the main objective of finding the optimal TECs design is to define a set of design parameters. In this paper, a new method of optimizing the dimension of TECs using simulated annealing (SA), to maximize the rate of refrigeration (ROR) was proposed. Equality constraint and inequality constraint were taken into consideration. This work reveals that SA shows better performance than Cheng's work. (paper)

  8. Fabrication of a Micro Cooler using Thermoelectric Thin Film

    International Nuclear Information System (INIS)

    Han, S. W.; Choi, H. J.; Kim, D. H.; Kim, W. J.; Kim, B. I.; Kim, K. M.

    2007-01-01

    In general a ThermoElectric Cooler (TEC) consists of a series of P type and N type thermoelectric materials sandwiched between two wafers. When a DC current passes through these materials, three different effects take place; Peltier effect, Joule heating effect and heat transfer by conduction due to temperature difference between hot and cold plates. In this study we have developed a micro TEC using Bi2Te3 (N type) and Bi0.5Sb1.5Te3 (P type) thin films. In order to improve that performance of a micro TEC, we made 10 um height TE legs using special PR only for lift-off. We measured COP (coefficient of performance) and temperature difference between hot and cold connectors with current

  9. Robust Temperature Control of a Thermoelectric Cooler via μ -Synthesis

    Science.gov (United States)

    Kürkçü, Burak; Kasnakoğlu, Coşku

    2018-02-01

    In this work robust temperature control of a thermoelectric cooler (TEC) via μ -synthesis is studied. An uncertain dynamical model for the TEC that is suitable for robust control methods is derived. The model captures variations in operating point due to current, load and temperature changes. A temperature controller is designed utilizing μ -synthesis, a powerful method guaranteeing robust stability and performance. For comparison two well-known control methods, namely proportional-integral-derivative (PID) and internal model control (IMC), are also realized to benchmark the proposed approach. It is observed that the stability and performance on the nominal model are satisfactory for all cases. On the other hand, under perturbations the responses of PID and IMC deteriorate and even become unstable. In contrast, the μ -synthesis controller succeeds in keeping system stability and achieving good performance under all perturbations within the operating range, while at the same time providing good disturbance rejection.

  10. Optimization of a microfluidic electrophoretic immunoassay using a Peltier cooler.

    Science.gov (United States)

    Mukhitov, Nikita; Yi, Lian; Schrell, Adrian M; Roper, Michael G

    2014-11-07

    Successful analysis of electrophoretic affinity assays depends strongly on the preservation of the affinity complex during separations. Elevated separation temperatures due to Joule heating promotes complex dissociation leading to a reduction in sensitivity. Affinity assays performed in glass microfluidic devices may be especially prone to this problem due to poor heat dissipation due to the low thermal conductivity of glass and the large amount of bulk material surrounding separation channels. To address this limitation, a method to cool a glass microfluidic chip for performing an affinity assay for insulin was achieved by a Peltier cooler localized over the separation channel. The Peltier cooler allowed for rapid stabilization of temperatures, with 21°C the lowest temperature that was possible to use without producing detrimental thermal gradients throughout the device. The introduction of cooling improved the preservation of the affinity complex, with even passive cooling of the separation channel improving the amount of complex observed by 2-fold. Additionally, the capability to thermostabilize the separation channel allowed for utilization of higher separation voltages than what was possible without temperature control. Kinetic CE analysis was utilized as a diagnostic of the affinity assay and indicated that optimal conditions were at the highest separation voltage, 6 kV, and the lowest separation temperature, 21°C, leading to 3.4% dissociation of the complex peak during the separation. These optimum conditions were used to generate a calibration curve and produced 1 nM limits of detection, representing a 10-fold improvement over non-thermostated conditions. This methodology of cooling glass microfluidic devices for performing robust and high sensitivity affinity assays on microfluidic systems should be amenable in a number of applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Kayser-Fleischer Rings

    Science.gov (United States)

    ... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

  12. Modeling of a regenerative indirect evaporative cooler for a desiccant cooling system

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Reinholdt, Lars O.

    This paper presents a numerical study of a regenerative indirect evaporative cooler, the so-called Dew Point Cooler (DPC), which is part of a Desiccant Cooling system that may both dehumidify and cool humid air. The DPC model is based on first principles using a 1D finite volume scheme...

  13. 20 K continuous cycle sorption coolers for the Planck flight mission

    Science.gov (United States)

    Bhandari, P.; Prina, M.; Bowman, R. C., Jr.; Paine, C.; Pearson, D.; Nash, A.

    2003-01-01

    In this paper we present the level of maturity of the hydrogen sorption cooler technology at JPL by describing the design and how it has been validated at the subsystem and system levels. In addition, we will describe how such systems could be advantageously used for other space missions with similar needs and cooler attributes.

  14. ASSOCIATIVE RINGS SOLVED AS LIE RINGS

    Directory of Open Access Journals (Sweden)

    M. B. Smirnov

    2011-01-01

    Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

  15. Re-Condensation and Liquefaction of Helium and Hydrogen Using Coolers

    International Nuclear Information System (INIS)

    Green, Michael A.

    2009-01-01

    Coolers are used to cool cryogen free devices at temperatures from 5 to 30 K. Cryogen free cooling involves a temperature drop within the device being cooled and between the device and the cooler cold heads. Liquid cooling with a liquid cryogen distributed over the surface of a device combined with re-condensation can result in a much lower temperature drop between the cooler and the device being cooled. The next logical step beyond simple re-condensation is using a cooler to liquefy the liquid cryogen in the device. A number of tests of helium liquefaction and re-condensation of helium have been run using a pulse tube cooler in the drop-in mode. This report discusses the parameter space over which re-condensation and liquefaction for helium and hydrogen can occur.

  16. Thermal analysis for steering cooler and hose to reduce product design cost

    International Nuclear Information System (INIS)

    Wang, L.

    2002-01-01

    This paper describes the procedures to conduct a thermal analysis to determine the right sizing of a typical steering cooler and hose system. A commercial CFD (Computational Fluid Dynamics) package, Star-CD, was used to solve the heat transfer problem. Instead of modelling the actual finned cooler, a porous media box cooler was simulated in the analysis and the effective conductivity for the box cooler was obtained through the simulation of a submodel, which was consisted of one layer of the aluminium fin and two layers of air around it. A user-defined subroutine was used in the simulation to correctly represent the contact area in the box cooler. In addition, a comparison between the numerical results and the experimental testing was provided. The good agreement between them validates the methodology used in this analysis. (author)

  17. Measurement of spin motions in a storage ring outside the stable polarization direction

    International Nuclear Information System (INIS)

    Akchurin, N.; Badano, L.; Bravar, A.; Istituto Nazionale di Fisica Nucleare, Legnaro

    1993-06-01

    Polarized, stored beams are becoming a more and more important tool in nuclear and high energy physics. In order to measure the beam polarization in a storage ring the polarization vector of the stored beams has to aim, revolution for revolution, over a period of seconds to minutes, into the same, so-called ''stable'' direction. In this paper measurements at the Indiana University cooler ring (IUCF) are described in which for the first time in a storage ring oscillations of the polarization vector around this stable direction have been measured. The existence and the dynamics of such oscillations are, for instance, important for a new proposed technique for polarizing stored hadron beams

  18. Advances in electron cooling in heavy-ion storage rings

    International Nuclear Information System (INIS)

    Danared, H.

    1994-01-01

    The efficiency of electron cooling can be improved by reducing the temperature of the electrons. If the magnetic field at the location of the electron gun is stronger than in the region where the electrons interact with the ions, and the field gradient is adiabatic with respect to the cyclotron motion of the electrons, the resulting expansion of the electron beam reduces its transverse temperature by a factor equal to the ratio between the two fields. A ten times expanded electron beam was introduced in the CRYRING electron cooler in the summer of 1993, and similar arrangements have since then been made at the TSR ring in Heidelberg and at ASTRID in Aarhus. The reduction of the transverse electron temperature has increased cooling rates with large factors, and improves the energy resolution and increases count rates when the cooler is used as an electron target for ion-electron recombination experiments

  19. Developments for the HITRAP cooler trap and mass measurements around A = 96 at SHIPTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Koszudowski, Stephen

    2009-07-08

    The HITRAP (Highly charged Ions Trap) facility is currently being set up and commissioned at GSI in Darmstadt. It will provide bunches of 10{sup 5} heavy highly-charged ions, for example hydrogen-like uranium (U{sup 91+}), to high-precision atomic physics experiments. The ions are produced by the GSI accelerator complex and decelerated to 4 MeV/u in the Experimental Storage Ring. Then the ions are decelerated by a two-step linear decelerator down to 6 keV/u. The first deceleration step down to 500 keV/u was successfully commissioned. The decelerated ions are injected into a Penning trap (the Cooler Trap), where they are cooled to 4 K by electron and resistive cooling. Resonant circuits for non-destructive detection and the resistive cooling of the trapped particles were designed and tested. The time control of the trap-cycle (trapping, cooling, extraction) with a time resolution of 25 ns was implemented into the control system CS. CS is also used at the mass measurement Penning trap SHIPTRAP, where the new time control is successfully operated. SHIPTRAP measures radioactive ions stemming from fusion evaporation reactions at the velocity filter SHIP. The masses of 9 nuclides ({sup 93,94,95}Technetium, {sup 94,96}Ruthenium, {sup 95,96,97,98}Rhodium) near the line of stability were precisely measured and compared with the Atomic Mass Evaluation. The detection of isomeric states with the present SHIPTRAP set-up was studied. (orig.)

  20. Analysis of closed orbit deviations for a first direct deuteron electric dipole moment measurement at the cooler synchrotron COSY

    Science.gov (United States)

    Schmidt, V.; Lehrach, A.

    2017-07-01

    The Jülich Electric Dipole moment Investigations (JEDI) collaboration in Julich is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. Ensuring a precise measurement, various beam and spin manipulating effects have to be considered and investigated. A distortion of the closed orbit is one of the major sources for systematic uncertainties. Therefore misalignments of magnets and residual power supply oscillations are simulated using the MAD-X code in order to analyse their effect on the orbit. The underlying model for all simulations includes the dipoles, quadrupoles and sextupoles at COSY as well as the corrector magnets and BPMs (Beam Position Monitors). Since most sextupoles are only used during beam extraction, the sextupole strengths are set to zero resulting in a linear machine. The optics is adjusted in a way that the dispersion is zero in the straight sections. The closed orbit studies are performed for deuterons with a momentum of 970 MeV/c.

  1. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  2. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  3. Simulations of injection optics for an RFQ cooler and buncher

    CERN Document Server

    Eronen, Tommi

    2002-01-01

    This report is about injection of ions to a new RFQ (which stands for a Radio Frequency Quadrupole) cooler & trap which will be built at ISOLDE, CERN. This device brings very good advantages to existing beamline - for instance, lower emittance in transversal plane and lower energy spread in longitudinal direction. It will be possible to bunch the beam. Lower emittance means that ions can be focused to smaller spot thus improving precision of measurements. For laser experiments bunched beam is much more useful compared to continuous beam. Bunch can be adjusted such that lasers are synchronized with the ion bunch thus increasing signal-to-background ratio. Using buffer gas cooling is also very cost effective and easy to operate - there is only a few tunable parameters in the RFQ. Buffer gas cooling is effective only if ions are much heavier than the buffer gas. Usually this is the case at ISOLDE. One of the most crucial part in the whole RFQ project is the injection. Because of the presence of buffer gas, R...

  4. Method for thermoelectric cooler utilization using manufacturer's technical information

    Science.gov (United States)

    Ajiwiguna, Tri Ayodha; Nugroho, Rio; Ismardi, Abrar

    2018-03-01

    Thermoelectric cooler (TEC) module has been widely used for many applications. In this study, a procedure to use TEC module for specific requirement is developed based on manufacturer's technical data. For study case, the cooling system using TEC module is designed and tested to maintain 6.6 liter of water at 24 °C while surrounding temperature is 26 °C. First, cooling load estimation is performed empirically by observing the temperature change when cold water is inside the container. Second, the working temperature on hot side and cold side of TEC are determined. Third, the parameters of Seebeck coefficient, thermal resistance and electrical resistance are predicted by using information from the manufacturer. Fourth, the operating current is determined by the assumption the voltage across the TEC is 12V. Fifth, cooling capacity of TEC module is calculated by using energy balance equation of TEC. Sixth, the cooling load and cooling capacity are compared to determine the number of TEC module needed. The result of these calculations showed that one TEC module is enough for cooling system since the cooling load is 17.5 W while the cooling capacity is 18.87 W. From the experimental result, the set point temperature was achieved using one TEC module as predicted in calculations steps.

  5. COSY, proposal for a cooler synchrotron at the KFA Julich

    International Nuclear Information System (INIS)

    Berg, G.P.A.; Gaul, G.; Hacker, H.

    1986-01-01

    The Cooler Synchrotron COSY is being planned in cooperation between scientists of the Kernforschungsanlage Julich, nuclear physicists of the neighbouring universities and other interested scientists. COSY is designed to provide beams of very light ions with energies ranging from 40 MeV to a maximum of 2.5 GeV for protons. This energy range allows a variety of studies in the so called energy window between 150 and 500 MeV, and it permits different kinds of investigations in the medium-energy region including the KΛ-threshold. Both electron cooling and stochastic cooling are foreseen in order to obtain very high phase-space density. The existing isochronous cyclotron JULIC will serve as injector. COSY will contain two bending sections, each consisting of three unit cells, and two long straight sections between the bends. Large flexibility is guaranteed by the ion-optical design. Experiments are being planned that make use either of the high quality external beam prepared by slow extraction or of the very high luminosity that is effective in the recirculator mode of operation

  6. Optimal operation of thermoelectric cooler driven by solar thermoelectric generator

    International Nuclear Information System (INIS)

    Khattab, N.M.; El Shenawy, E.T.

    2006-01-01

    The possibility of using a solar thermoelectric generator (TEG) to drive a small thermoelectric cooler (TEC) is studied in the present work. The study includes the theory of both the TEG and the TEC, giving special consideration to determination of the number of TEG modules required to power the TEC to achieve the best performance of the TEG-TEC system all year round. Commercially available thermoelectric modules (TE) are used in the system. The TEG contains 49 thermocouples and the TEC contains 127 thermocouples. A simple arrangement of plane reflectors that are designed to receive maximum solar energy during noon time is used to heat the TEG. Performance tests are conducted to determine both the physical properties and the performance curves of the available TE modules. Also, empirical relations describing the performance of the TEG and TEC modules have been established. These relations are used to develop a mathematical model simulating the TEG-TEC system to predict its performance all year round under the actual climatic conditions of Cairo, Egypt (30 deg. N latitude). The model results are used to determine the number of TEG modules required to drive a single TEC module at maximum cooling capacity. The results show that five thermocouples of the TEG can drive one thermocouple of the TEC, which coincides with the previous theory of the TEG-TEC. This means that 10 of the used TEG modules are required to power the used TEC at optimum performance most times of the year

  7. Boiling process in oil coolers on porous elements

    Directory of Open Access Journals (Sweden)

    Genbach Alexander A.

    2016-01-01

    Full Text Available Holography and high-speed filming were used to reveal movements and deformations of the capillary and porous material, allowing to calculate thermo-hydraulic characteristics of boiling liquid in the porous structures. These porous structures work at the joint action of capillary and mass forces, which are generalised in the form of dependences used in the calculation for oil coolers in thermal power plants (TPP. Furthermore, the mechanism of the boiling process in porous structures in the field of mass forces is explained. The development process of water steam formation in the mesh porous structures working at joint action of gravitational and capillary forces is investigated. Certain regularities pertained to the internal characteristics of boiling in cells of porous structure are revealed, by means of a holographic interferometry and high-speed filming. Formulas for calculation of specific thermal streams through thermo-hydraulic characteristics of water steam formation in mesh structures are obtained, in relation to heat engineering of thermal power plants. This is the first calculation of heat flow through the thermal-hydraulic characteristics of the boiling process in a reticulated porous structure obtained by a photo film and holographic observations.

  8. The performance evaluation of a micro/nano-scaled cooler working with an ideal Bose gas

    International Nuclear Information System (INIS)

    Guo, Juncheng; Su, Guozhen; Chen, Jincan

    2012-01-01

    Based on the size effect of a confined ideal Bose gas, the design concept of a quantum cooler is originally put forward. The cooler consists of two long tubes with the same length but different sizes of cross section, which are filled up with the ideal Bose gas, and is operated between two heat reservoirs. Expressions for the refrigeration rate and coefficient of performance (COP) of the cooler are derived. The effects of the size effect on the refrigeration rate and COP are discussed. The general performance characteristics of the cooler are revealed. -- Highlights: ► The design concept of a quantum cooler is originally put forward. ► Expressions for the refrigeration rate and coefficient of performance (COP) of the cooler are derived. ► The effects of the size effect on the refrigeration rate and COP are discussed. ► The general performance characteristics of the cooler are revealed. ► The results obtained are more general and significant than those in the current literature.

  9. Inter-cooler in solar-assisted refrigeration system: Theory and experimental verification

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2015-01-01

    Full Text Available An inter-cooler in the solar-assisted refrigeration system was investigated experimentally and theoretically, and the theoretical prediction was fairly in good agreement with the experimental data. The influence of pipe diameter, tooth depth, and spiral angle of inter-cooler on the performance of the refrigerant system was analyzed. It was concluded that heat transfer is influenced deeply by the structure parameters of inter-cooler, and the heat transfer capacity increases with tooth depth and spiral angle increasing, and decreases with tooth apex angle increasing.

  10. Addressing Water Consumption of Evaporative Coolers with Greywater

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, Rashmi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-07-01

    Evaporative coolers (ECs) provide significant gains in energy efficiency compared to vapor compression air conditioners, but simultaneously have significant onsite water demand. This can be a major barrier to deployment in areas of the world with hot and arid climates. To address this concern, this study determined where in the world evaporative cooling is suitable, the water consumption of ECs in these cities, and the potential that greywater can be used reduce the consumption of potable water in ECs. ECs covered 69percent of the cities where room air conditioners are may be deployed, based on comfort conditions alone. The average water consumption due to ECs was found to be 400 L/household/day in the United States and Australia, with the potential for greywater to provide 50percent this amount. In the rest of the world, the average water consumption was 250 L/household/day, with the potential for greywater to supply 80percent of this amount. Home size was the main factor that contributed to this difference. In the Mediterranean, the Middle East, Northern India, and the Midwestern and Southwestern United States alkalinity levels are high and water used for bleeding will likely contribute significantly to EC water consumption. Although technically feasible, upfront costs for household GW systems are currently high. In both developed and developing parts of the world, however, a direct EC and GW system is cost competitive with conventional vapor compression air conditioners. Moreover, in regions of the world that face problems of water scarcity the benefits can substantially outweigh the costs.

  11. Numerical study on interaction of local air cooler with stratified hydrogen cloud in a large vessel

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Z. [Atomic Energy of Canada Limited, Chalk River Laboratories, ON K0J 1J0 (Canada); Andreani, M. [Laboratory for Thermal-Hydraulics, Paul Scherrer Institut, 5232 Villigen (Switzerland)

    2012-07-01

    Within the framework of the ERCOSAM project, planning calculations are performed to examine sensitivity parameters that can affect the break-up (erosion) of a helium layer by mitigation devices (i.e., cooler, spray, or Passive Autocatalytic Recombiner - PAR). This paper reports the GOTHIC analysis results for the cooler tests to be performed in the PANDA facility. The cooler elevation and geometry, helium layer thickness, steam distribution in the vessel, and the vessel geometry (inter-connected multi-compartments versus a single volume) on the erosion process as well as the cooling capacity are studied. This analysis is valuable because only a limited number of conditions will be examined in the planned experiments. The study provides a useful understanding of the interaction of a cooler with a stratified atmosphere. (authors)

  12. Experimental characterization of the Hitrap Cooler trap with highly charged ions.

    OpenAIRE

    Fedotova, Svetlana

    2013-01-01

    The HITRAP (Highly charged Ions TRAP)facility is being set up and commissioned at GSI, Darmstadt. It will provide heavy, highly charged ions at low velocities to high-precision atomic physics experiments. Within this work the Cooler trap- the key element of the HITRAP facility was tested. The Cooler trap was assembled, aligned, and commissioned in trapping experiments with ions from off-line sources.The work performed within the scope of this thesis provided the baseline for further operation...

  13. MEMS based shock pulse detection sensor for improved rotary Stirling cooler end of life prediction

    Science.gov (United States)

    Hübner, M.; Münzberg, M.

    2018-05-01

    The widespread use of rotary Stirling coolers in high performance thermal imagers used for critical 24/7 surveillance tasks justifies any effort to significantly enhance the reliability and predictable uptime of those coolers. Typically the lifetime of the whole imaging device is limited due to continuous wear and finally failure of the rotary compressor of the Stirling cooler, especially due to failure of the comprised bearings. MTTF based lifetime predictions, even based on refined MTTF models taking operational scenario dependent scaling factors into account, still lack in precision to forecast accurately the end of life (EOL) of individual coolers. Consequently preventive maintenance of individual coolers to avoid failures of the main sensor in critical operational scenarios are very costly or even useless. We have developed an integrated test method based on `Micro Electromechanical Systems', so called MEMS sensors, which significantly improves the cooler EOL prediction. The recently commercially available MEMS acceleration sensors have mechanical resonance frequencies up to 50 kHz. They are able to detect solid borne shock pulses in the cooler structure, originating from e.g. metal on metal impacts driven by periodical forces acting on moving inner parts of the rotary compressor within wear dependent slack and play. The impact driven transient shock pulse analyses uses only the high frequency signal <10kHz and differs therefore from the commonly used broadband low frequencies vibrational analysis of reciprocating machines. It offers a direct indicator of the individual state of wear. The predictive cooler lifetime model based on the shock pulse analysis is presented and results are discussed.

  14. Rings in drugs.

    Science.gov (United States)

    Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G

    2014-07-24

    We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.

  15. Birth Control Ring

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

  16. Calculation of forces on reactor containment fan cooler piping

    International Nuclear Information System (INIS)

    Miller, J.S.; Ramsden, K.

    2004-01-01

    The purpose of this paper is to present the results of the Reactor Containment Fan Cooler (RCFC) system piping load calculations. These calculations are based on piping loads calculated using the EPRI methodology and RELAP5 to simulate the hydraulic behavior of the system. The RELAP5 generated loads were compared to loads calculated using the EPRI GL-96-06 methodology. This evaluation was based on a pressurized water reactor's RCFC coils thermal hydraulic behavior during a Loss of Offsite Power (LOOP) and a loss of coolant accident (LOCA). The RCFC consist of two banks of service water and chill water coils. There are 5 SX and 5 chill water coils per bank. Therefore, there are 4 RCFC units in the containment with 2 banks of coils per RCFC. Two Service water pumps provide coolant for the 4 RCFC units (8 banks total, 2 banks per RCFC unit and 2 RCFC units per pump). Following a LOOP/LOCA condition, the RCFC fans would coast down and upon being re-energized, would shift to low-speed operation. The fan coast down is anticipated to occur very rapidly due to the closure of the exhaust damper as a result of LOCA pressurization effects. The service water flow would also coast down and be restarted in approximately 43 seconds after the initiation of the event. The service water would drain from the RCFC coils during the pump shutdown and once the pumps restart, water is quickly forced into the RCFC coils causing hydraulic loading on the piping. Because of this scenario and the potential for over stressing the piping, an evaluation was performed by the utility using RELAP5 to assess the piping loads. Subsequent to the hydraulic loads being analyzed using RELAP5, EPRI through GL-96-06 provided another methodology to assess loads on the RCFC piping system. This paper presents the results of using the EPRI methodology and RELAP5 to perform thermal hydraulic load calculations. It is shown that both EPRI methodology and RELAP5 calculations can be used to generate hydraulic loads

  17. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  18. THE ERL HIGH-ENERGY COOLER FOR RHIC

    International Nuclear Information System (INIS)

    BEN-ZVI, I.

    2006-01-01

    Electron cooling [1] entered a new era with the July 2005 cooling of the Tevatron recycler ring [2] at Fermilab, using γ = 9.5. Considering that the cooling rate decreases as faster than γ 2 and the electron energy forces higher electron currents, new acceleration techniques, high-energy electron cooling presents special challenges to the accelerator scientists and engineers. For example, electron cooling of RHIC at collisions requires electron beam energy up to about 54 MeV at an average current of between 50 to 100 mA and a particularly bright electron beam. The accelerator chosen to generate this electron beam is a superconducting Energy Recovery Linac (ERL) with a superconducting RF gun with a laser-photocathode

  19. Detailed description of the Ócsa Bird Ringing Station, Hungary

    OpenAIRE

    Csörgő Tibor; Harnos Andrea; Rózsa Lajos; Karcza Zsolt; Fehérvári Péter

    2016-01-01

    The present paper acts as an introduction to a series that will describe the exploratory analyses of migration phenology and morphometrics of the most common passerine species at the Ócsa Bird Ringing Station. This station is situated in the Ócsa Landscape Protection Area that belongs to the Duna–Ipoly National Park, Hungary. The area is somewhat cooler and more humid than the surrounding agricultural fields and tree plantations, covered by a mosaic of diverse hygrophilous vegetation patches....

  20. FPGA-based upgrade of the read-out electronics for the low energy polarimeter at the cooler synchrotron

    Energy Technology Data Exchange (ETDEWEB)

    Hempelmann, Nils [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Collaboration: JEDI-Collaboration

    2015-07-01

    The Cooler Synchrotron (COSY) is a storage ring used for experiments with polarized proton and deuteron beams. The low energy polarimeter is used to determine the vector and tensor polarization of the beam before injection at kinetic energies up to 45 MeV for protons and 75 MeV for deuterons. The polarimeter uses scintillators to measure the energy of both outgoing particles of a scattering reaction and the time between their detection. The present read-out electronics consists of analog NIM modules and is limited in terms of time resolution and the capability for online data analysis. The read-out electronics will be replaced with a a new system based on analog pulse sampling and an FPGA chip for logic operations. The new system will be able to measure the time at which particles arrive to a precision better than 50 ps, facilitating better background reduction using coincidence measurement. In addition to measuring the beam polarization, the system will be used to precisely determine the vector and tensor analyzing powers for deuteron scattering off carbon at a kinetic energy of 75 MeV.

  1. Reliability improvements on Thales RM2 rotary Stirling coolers: analysis and methodology

    Science.gov (United States)

    Cauquil, J. M.; Seguineau, C.; Martin, J.-Y.; Benschop, T.

    2016-05-01

    The cooled IR detectors are used in a wide range of applications. Most of the time, the cryocoolers are one of the components dimensioning the lifetime of the system. The cooler reliability is thus one of its most important parameters. This parameter has to increase to answer market needs. To do this, the data for identifying the weakest element determining cooler reliability has to be collected. Yet, data collection based on field are hardly usable due to lack of informations. A method for identifying the improvement in reliability has then to be set up which can be used even without field return. This paper will describe the method followed by Thales Cryogénie SAS to reach such a result. First, a database was built from extensive expertizes of RM2 failures occurring in accelerate ageing. Failure modes have then been identified and corrective actions achieved. Besides this, a hierarchical organization of the functions of the cooler has been done with regard to the potential increase of its efficiency. Specific changes have been introduced on the functions most likely to impact efficiency. The link between efficiency and reliability will be described in this paper. The work on the two axes - weak spots for cooler reliability and efficiency - permitted us to increase in a drastic way the MTTF of the RM2 cooler. Huge improvements in RM2 reliability are actually proven by both field return and reliability monitoring. These figures will be discussed in the paper.

  2. HISTRAP [Heavy Ion Storage Ring for Atomic Physics] prototype hardware studies

    International Nuclear Information System (INIS)

    Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.

    1989-01-01

    HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs

  3. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2007-01-01

    Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

  4. NASA Lewis Stirling SPRE testing and analysis with reduced number of cooler tubes

    International Nuclear Information System (INIS)

    Wong, W.A.; Cairelli, J.E.; Swec, D.M.; Doeberling, T.J.; Lakatos, T.F.; Madi, F.J.

    1994-01-01

    Free-piston Stirling power converters are a candidate for high capacity space power applications. The Space Power Research Engine (SPRE), a free-piston Stirling engine coupled with a linear alternator, is being tested at the NASA Lewis Research Center in support of the Civil Space Technology Initiative. The SPRE is used as a test bed for evaluating converter modifications which have the potential to improve converter performance and for validating computer code predictions. Reducing the number of cooler tubes on the SPRE has been identified as a modification with the potential to significantly improve power and efficiency. This paper describes experimental tests designed to investigate the effects of reducing the number of cooler tubes on converter power, efficiency and dynamics. Presented are test results from the converter operating with a reduced number of cooler tubes and comparisons between this data and both baseline test data and computer code predictions

  5. Performance Analysis of Joule-Thomson Cooler Supplied with Gas Mixtures

    Science.gov (United States)

    Piotrowska, A.; Chorowski, M.; Dorosz, P.

    2017-02-01

    Joule-Thomson (J-T) cryo-coolers working in closed cycles and supplied with gas mixtures are the subject of intensive research in different laboratories. The replacement of pure nitrogen by nitrogen-hydrocarbon mixtures allows to improve both thermodynamic parameters and economy of the refrigerators. It is possible to avoid high pressures in the heat exchanger and to use standard refrigeration compressor instead of gas bottles or high-pressure oil free compressor. Closed cycle and mixture filled Joule-Thomson cryogenic refrigerator providing 10-20 W of cooling power at temperature range 90-100 K has been designed and manufactured. Thermodynamic analysis including the optimization of the cryo-cooler mixture has been performed with ASPEN HYSYS software. The paper describes the design of the cryo-cooler and provides thermodynamic analysis of the system. The test results are presented and discussed.

  6. Micro-coolers fabricated as a component in an integrated circuit

    International Nuclear Information System (INIS)

    Glover, James; Oxley, Chris H; Khalid, Ata; Cumming, David; Stephen, Alex; Dunn, Geoff

    2015-01-01

    The packing density and power capacity of integrated electronics is increasing resulting in higher thermal flux densities. Improved thermal management techniques are required and one approach is to include thermoelectric coolers as part of the integrated circuit. An analysis will be described showing that the supporting substrate will have a large influence on the cooling capacity of the thermoelectric cooler. In particular, for materials with a low ZT figure of merit (for example gallium arsenide (GaAs) based compounds) the substrate will have to be substantially thinned to obtain cooling, which may preclude the use of thermoelectric coolers, for example, as part of a GaAs based integrated circuit. Further, using experimental techniques to measure only the small positive cooling temperature difference (ΔT) between the anode (T h ) and the cathode (T c ) contacts can be misinterpreted as cooling when in fact it is heating. (paper)

  7. Influence of the outlet air temperature on the thermohydraulic behaviour of air coolers

    Directory of Open Access Journals (Sweden)

    Đorđević Emila M.

    2003-01-01

    Full Text Available The determination of the optimal process conditions for the operation of air coolers demands a detailed analysis of their thermohydraulic behaviour on the one hand, and the estimation of the operating costs, on the other. One of the main parameters of the thermohydraulic behaviour of this type of equipment, is the outlet air temperature. The influence of the outlet air temperature on the performance of air coolers (heat transfer coefficient overall heat transfer coefficient, required surface area for heat transfer air-side pressure drop, fan power consumption and sound pressure level was investigated in this study. All the computations, using AirCooler software [1], were applied to cooling of the process fluid and the condensation of a multicomponent vapour mixture on two industrial devices of known geometries.

  8. Modeling of Hydrate Formation Mode in Raw Natural Gas Air Coolers

    Science.gov (United States)

    Scherbinin, S. V.; Prakhova, M. Yu; Krasnov, A. N.; Khoroshavina, E. A.

    2018-05-01

    Air cooling units (ACU) are used at all the gas fields for cooling natural gas after compressing. When using ACUs on raw (wet) gas in a low temperature condition, there is a danger of hydrate plug formation in the heat exchanging tubes of the ACU. To predict possible hydrate formation, a mathematical model of the air cooler thermal behavior used in the control system shall adequately calculate not only gas temperature at the cooler's outlet, but also a dew point value, a temperature at which condensation, as well as the gas hydrate formation point, onsets. This paper proposes a mathematical model allowing one to determine the pressure in the air cooler which makes hydrate formation for a given gas composition possible.

  9. Token ring technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

  10. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

    Miller, R.A.; Aldrich, J.E.

    1990-01-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

  11. Physics of quantum rings

    International Nuclear Information System (INIS)

    Fomin, Vladimir M.

    2014-01-01

    Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

  12. Development and Evaluation of a Sandia Cooler-based Refrigerator Condenser

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kariya, Harumichi Arthur [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Leick, Michael T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zimmerman, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Li, Manjie [Univ. of Maryland, College Park, MD (United States); Du, Yilin [Univ. of Maryland, College Park, MD (United States); Lee, Hoseong [Univ. of Maryland, College Park, MD (United States); Hwang, Yunho [Univ. of Maryland, College Park, MD (United States); Radermacher, Reinhard [Univ. of Maryland, College Park, MD (United States)

    2015-07-01

    This report describes the first design of a refrigerator condenser using the Sandia Cooler, i.e. air - bearing supported rotating heat - sink impeller. The project included ba seline performance testing of a residential refrigerator, analysis and design development of a Sandia Cooler condenser assembly including a spiral channel baseplate, and performance measurement and validation of this condenser system as incorporated into the residential refrigerator. Comparable performance was achieved in a 60% smaller volume package. The improved modeling parameters can now be used to guide more optimized designs and more accurately predict performance.

  13. On the design criteria for the evaporated water flow rate in a wet air cooler

    International Nuclear Information System (INIS)

    Bourillot, C.

    1982-01-01

    The author discusses Poppe's formulation used for the modelling of heat exchangers between air and water, in Electricite de France's TEFERI numerical wet atmospheric cooler model: heat transfer laws in unsaturated and saturated air, Bosnjakivic's formula, evaporation coefficient. The theorical results show good agreement with the measurements taken on Neurath's cooler C in West Germany, whatever the ambient temperature (evaporated water flow rate, condensate content of warm air). The author then demonstrates the inadequacy of Merkel's method for calculating evaporated water flow rates, and estimates the influence of the assumptions made on the total error [fr

  14. EBT ring physics

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers

  15. Performance of the natural cooler to keep the freshness of vegetables and fruits in Medan City

    Science.gov (United States)

    Sitorus, T. B.; Ambarita, H.; Ariani, F.; Sitepu, T.

    2018-02-01

    One application in a direct evaporative cooling system was a natural cooler. The advantages of this system were not using the electrical energy and so far also environmentally. This research aims to obtain a performance analysis of the natural cooler as a store for vegetables and fruits in Medan city. The materials for natural cooler consists of teak wood and gunny. This study makes experiments during seven days in the open air. The parameter measurement on the weather was using HOBO devices and to record the temperature changes for vegetables or even fruits is using its acquisition data. The results showed that the maximum efficiency of the natural cooler could be obtained for 43.79% in the average air temperature of 30.51°C, the air humidity average is 85.12% with average solar radiation of 183.98 W/m2. Experimental data were showing that the condition of freshness on vegetables or even on fruits was heavily influenced by weather conditions.

  16. Material Selection for Competition–A Case Study for Air Coolers

    Directory of Open Access Journals (Sweden)

    Luma A. H. Al Kindi

    2018-02-01

    Full Text Available Competition is one of the most important challenges that is facing the marketing of industrial products in today's markets. In this research study of the impact of material selection factor for air coolers of different materials is applied. Investigation on the air cooler windows which are part of the body of air coolers is conducted. Corrosion resistance, thermal conductivity, strength of material, weight, shape, cost and manufacturing process are the factors that are applied and calculated on three types of materials Aluminum, Galvanized steel and polypropylene. The physical properties of the three mentioned materials are used to calculate Merit Index .The corrosion average, according to Tafel Method depending the corrosion current and adopting contactors for the anodic and cathodic metals behaviors is performed. ANSYS is adopted using the three samples for the selected materials Aluminum, Galvanized steel and polypropylene to measure maximum stress and deflection are measured. Accordingly, the results are compared to choose the best alternative. It is observed that the polypropylene is the best choice depending three factors while the aluminum material is better depending two factors and the galvanized steel is regarded as the best in only one factor, the rest factors are identical when choosing  an alternative material for manufacturing the air cooler windows.

  17. On Problem of Mathematical Modelling of Thermo-Physical Processes in Regenerative Water-Evaporating Coolers

    Science.gov (United States)

    Gulevsky, V. A.; Shatsky, V. P.; Osipov, E. I.; Menzhulova, A. S.

    2018-03-01

    For cooling the air environment of industrial premises water-evaporating air, conditioners are being increasingly applied. The simplicity of their construction, ecological safety and low power consumption distinguish them from the coolers of other types. Cooling the processed air is due to the loss of energy for the evaporation of moisture from the surface of the water-wetted plates that form air channels. As a result of this process, cooled air is often saturated with moisture, which limits the possibilities for the operation of the coolers of this type. In these cases, more complex coolers of indirect principle without such drawback should be applied. The most effective modification of indirect cooling is the installation of recuperative principle units. The paper presents a mathematical model of heat-mass transfer in such water-evaporating coolers. The scheme of realization of this model based on an iterative algorithm of solution of the system of finite–difference linear equations that takes into account longitudinal and transverse thermal conductivity of the heat transfer plates is suggested. The possibility of obtaining the optimal values of the redistribution of the main and auxiliary air flows through the substantiation of the aerodynamic resistance of the output grid is proved. This allows refusing the inclusion in the additional system cooling fan unit for discharging an auxiliary stream of air.

  18. Reemergence of Mycobacterium chimaera in Heater–Cooler Units despite Intensified Cleaning and Disinfection Protocol

    Science.gov (United States)

    Schreiber, Peter W.; Kuster, Stefan P.; Hasse, Barbara; Bayard, Cornelia; Rüegg, Christian; Kohler, Philipp; Keller, Peter M.; Bloemberg, Guido V.; Maisano, Francesco; Bettex, Dominique; Halbe, Maximilian; Sommerstein, Rami

    2016-01-01

    Invasive Mycobacterium chimaera infections after open-heart surgery have been reported internationally. These devastating infections result from aerosols generated by contaminated heater–cooler units used with extracorporeal circulation during surgery. Despite intensified cleaning and disinfection, surveillance samples from factory-new units acquired during 2014 grew nontuberculous mycobacteria after a median of 174 days. PMID:27649345

  19. Sensitivity of Micromachined Joule-Thomson Cooler to Clogging Due to Moisture

    NARCIS (Netherlands)

    Cao, Haishan; Vanapalli, Srinivas; Holland, Herman J.; Vermeer, Cristian Hendrik; ter Brake, Hermanus J.M.

    2015-01-01

    A major issue in long-term operation of micromachined Joule-Thomson coolers is the clogging of the microchannels and/or the restriction due to the deposition of water molecules present in the working fluid. In this study, we present the performance of a microcooler operated with nitrogen gas with

  20. Experimental investigation of a portable desalination unit configured by a thermoelectric cooler

    International Nuclear Information System (INIS)

    Yıldırım, Cihan; Soylu, Sezgi Koçak; Atmaca, İbrahim; Solmuş, İsmail

    2014-01-01

    Highlights: • Portable humidification–dehumidification desalination system configured by a thermoelectric cooler is experimentally studied. • Effect of feed water mass flow rate and air flow velocity on COP value of TEC and system productivity are investigated. • Maximum daily yield of system and COP value of TEC unit were recorded as 143.6 g and 0.78, respectively. - Abstract: Possible use of a novel portable desalination system was investigated experimentally. The system is based on humidification–dehumidification principle and thermoelectric cooling technique. A thermoelectric cooler was integrated into the system to enhance the process of both humidification and dehumidification. A prototype was fabricated and its performance was tested for various working conditions of the prototype to observe complex relation between psychrometric and thermoelectric phenomena. The effect of feed water mass flow rate and air flow velocity on the COP value of the thermoelectric cooler and clean water production of the system were examined. The maximum daily yield of the system and the COP value of the thermoelectric cooler unit were recorded as 143.6 g and 0.78, respectively

  1. The impact of fouling on performance evaluation of evaporative coolers and condensers

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, B.A.; Zubair, S.M. [King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia). Mechanical Engineering Dept.

    2005-11-15

    Fouling of evaporative cooler and condenser tubes is one of the most important factors affecting their thermal performance, which reduces effectiveness and heat transfer capability with time. In this paper, the experimental data on fouling reported in the literature are used to develop a fouling model for this class of heat exchangers. The model predicts the decrease in heat transfer rate with the growth of fouling. A detailed model of evaporative coolers and condensers, in conjunction with the fouling model, is used to study the effect of fouling on the thermal performance of these heat exchangers at different air inlet wet bulb temperatures. The results demonstrate that fouling of tubes reduces gains in performance resulting from decreasing values of air inlet wet bulb temperature. It is found that the maximum decrease in effectiveness due to fouling is about 55 and 78% for the evaporative coolers and condensers, respectively, investigated in this study. For the evaporative cooler, the value of process fluid outlet temperature T{sub p,out} varies by 0.66% only at the clean condition for the ambient wet bulb temperatures considered. (author)

  2. Improvement of the cooldown time of LSF 9599 flexure bearing SADA cooler

    NARCIS (Netherlands)

    Mullié, J.; Groep, van der W.; Bruins, P.; Benschop, T.; Koning, de A.; Dam, J.A.M.; Andresen, B.F.; Fulop, G.F.; Norton, P.R.

    2006-01-01

    Thales Cryogenics has presented the LSF 9599 SADA II flexure cooler in 2005. Based on Thales' well-known moving magnet flexure technology, the LSF 9599 complies with the SADA II specification with respect to performance, envelope and mass. Being the first manufacturer offering a full flexure-bearing

  3. Development and Testing of an Integrated Sandia Cooler Thermoelectric Device (SCTD).

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry A.; Staats, Wayne Lawrence,; Leick, Michael Thomas; Zimmerman, Mark D.; Radermacher, Reinhard; Martin, Cara; Nasuta, Dennis; Kalinowski, Paul; Hoffman, William

    2014-12-01

    This report describes a FY14 effort to develop an integrated Sandia Cooler T hermoelectric D evice (SCTD) . The project included a review of feasible thermoelectric (TE) cooling applications, baseline performance testing of an existing TE device, analysis and design development of an integrated SCTD assembly, and performance measurement and validation of the integrated SCTD prototype.

  4. Reemergence of Mycobacterium chimaera in Heater-Cooler Units despite Intensified Cleaning and Disinfection Protocol.

    Science.gov (United States)

    Schreiber, Peter W; Kuster, Stefan P; Hasse, Barbara; Bayard, Cornelia; Rüegg, Christian; Kohler, Philipp; Keller, Peter M; Bloemberg, Guido V; Maisano, Francesco; Bettex, Dominique; Halbe, Maximilian; Sommerstein, Rami; Sax, Hugo

    2016-10-01

    Invasive Mycobacterium chimaera infections after open-heart surgery have been reported internationally. These devastating infections result from aerosols generated by contaminated heater-cooler units used with extracorporeal circulation during surgery. Despite intensified cleaning and disinfection, surveillance samples from factory-new units acquired during 2014 grew nontuberculous mycobacteria after a median of 174 days.

  5. Numerical study on transverse asymmetry in the temperature profile of a regenerator in a pulse tube cooler

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Dietrich, M.; Carlsen, Henrik

    2007-01-01

    Transverse asymmetry in the temperature profile of the regenerator in a Stirling-type pulse tube cooler as observed in experiments was analysed in a numerical study. The asymmetry was reproduced using a one-dimensional model of the cooler where the regenerator was modelled using two identical...

  6. How the Performance of a Superconducting Magnet is affected by the Connection between a small cooler and the Magnet

    International Nuclear Information System (INIS)

    Green, Michael A.

    2005-01-01

    As low temperature cryocoolers become more frequently used to cool superconducting magnets, it becomes increasingly apparent that the connection between the cooler and the magnet has an effect on the design and performance of the magnet. In general, the use of small coolers can be considered in two different temperature ranges; (1) from 3.8 to 4.8 K for magnet fabricated with LTS conductor and (2) from 18 to 35 K for magnets fabricated using HTS conductor. In general, both temperature ranges call for the use of a two-stage cooler. The best method for connecting a cooler to the magnet depends on a number of factors. The factors include: (1) whether the cooler must be used to cool down the magnet from room temperature, (2) whether the magnet must have one or more reservoirs of liquid cryogen to keep the magnet cold during a loss of cooling, and (3) constraints on the distance from the cooler cold heads and the magnet and its shield. Two methods for connecting low temperature coolers to superconducting magnets have been studied. The first method uses a cold strap to connect the cold heads directly to the loads. This method is commonly used for cryogen-free magnets. The second method uses a thermal siphon and liquid cryogens to make the connection between the load being cooled and the cold head. The two methods of transferring heat from the magnet to the cooler low temperature cold head are compared for the two temperature ranges given above

  7. On the Laurent polynomial rings

    International Nuclear Information System (INIS)

    Stefanescu, D.

    1985-02-01

    We describe some properties of the Laurent polynomial rings in a finite number of indeterminates over a commutative unitary ring. We study some subrings of the Laurent polynomial rings. We finally obtain two cancellation properties. (author)

  8. Improvement of cooldown time of LSF9599 flexure-bearing SADA cooler

    Science.gov (United States)

    Mullié, Jeroen; vd Groep, Willem; Bruins, Peter; Benschop, Tonny; de Koning, Arjan; Dam, Jacques

    2006-05-01

    Thales Cryogenics has presented the LSF 9599 SADA II flexure cooler in 2005. Based on Thales' well-known moving magnet flexure technology, the LSF 9599 complies with the SADA II specification with respect to performance, envelope and mass. Being the first manufacturer offering a full flexure-bearing supported cooler that fits within the SADA II envelope, Thales Cryogenics has been selected in several new (military) programs with their LSF coolers. For many of these new programs, the cooldown time requirements are more stringent than in the past, whereas at the same time size, complexity and thus thermal mass of the infrared sensor tends to increase. In order to respond to the need created by the combination of these trends, Thales Cryogenics started a development program to optimize cryogenic performance of the LSF 9599 cooler. The main goal for the development program is to reduce the cooldown time, while maintaining the SADA II compatible interface, and maintaining the robustness and proven reliability of the cooler. Within these constraints, the regenerator was further optimized using among others the experience with mixed-gauze regenerators obtained from our pulse tube research. Using the mixed gauze approach, the heat storage capacity of the regenerator is adapted as a function of the temperature profile over the regenerator, thus giving the optimum balance between heat storage capacity and pressure drop. A novel way of constructing the regenerator further decreases shuttle heat losses and other thermal losses in the regenerator. This paper describes the first results of the trade-offs and gives an overview of impact on cooldown times and efficiency figures achieved after the regenerator and displacer optimization.

  9. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  10. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

    In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in

  11. COSY Juelich - a cooler synchrotron for unpolarized and polarized medium-energy studies

    International Nuclear Information System (INIS)

    Seyfarth, H.

    2001-01-01

    Full text: The Forschungszentrum Juelich (Research Center Juelich) is one of the sixteen national research institutions in the 'Hermann von Helmholtz Association of German Research Centers'. It is dedicated to fundamental and applied research and development which can be summarized under five priorities: (i) structure of matter and materials research, (ii) information technology, (iii) life sciences, (iv) environment precaution research, and (v) energy technology. As one of the institutes within (i). the Institut fur Kernphysik (Institute for Nuclear Research) operates the COSY cooler synchrotron which allows to accelerate unpolarized and polarized protons and deuterons to the maximum momentum of 3450 MeV/c (2640 MeV and 2050 MeV kinetic energy for protons and deuterons, respectively). At low energy electron cooling can be used for beam preparation, whereas stochastic cooling can be applied to the accelerated beam. In the first years of operation since 1993 the experiments have been performed with the unpolarized proton beam. Since 1997 the polarized proton beam is available with increasing intensity and a typical degree of polarization of about 75 % up to the maximum beam energy. In 2000 the first unpolarized deuteron beam could be accelerated and stored at the maximum energy. Four target places exist for the internal experiments PISA. EDDA, COSY-II, and ANKE which use the circulating beam with thin solid strip or fiber targets and gas targets. The four experiments TOF, MOMO, GEM, NESSI, and JESSICA are using external beams. The programs of the experiments JESSICA (Juelich Experimental Spallation Setup in the COSY Area), NESSI (Neutron Scintillator and Silicon), and PISA (Proton Induced Spallation) aim at the measurement of data needed or the design of the target station of the planned European Spallation neutron Source (ESS). The set-up of PISA is replacing the earlier experiment COSY-13 which successfully completed its investigations on the production of

  12. On arbitrarily graded rings

    Indian Academy of Sciences (India)

    58

    paper is devoted to the study of arbitrary rings graded through arbitrary sets. .... which recover certain multiplicative relations among the homogeneous components ... instance the case in which the grading set A is an Abelian group, where the ...

  13. The g-2 ring

    CERN Multimedia

    1974-01-01

    The precise measurement of "g-2", the anomalous magnetic moment of the muon, required a special muon storage ring with electrostatic focussing and very accurate knowledge of the magnetic bending field. For more details see under photo 7405430.

  14. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

    So called Liesegang's rings are lamellar corpuscles which develop after periodical precipitation of oversaturated solutions in gel medium. They can occur in cysts, closed cavities, inflammatory exudates and necroses. They resemble parasitic eggs, larvae or adult forms. A case of 28-year-old woman is presented with many Liesegang's rings in a stuff from dilated renal calyx. Their preliminary evaluation considered helminths, especially Dioctophyma renale.

  15. Storage ring group summary

    International Nuclear Information System (INIS)

    King, N.M.

    1980-01-01

    The Storage Ring Group set out to identify and pursue salient problems in accelerator physics for heavy ion fusion, divorced from any particular reference design concept. However, it became apparent that some basic parameter framework was required to correlate the different study topics. As the Workshop progressed, ring parameters were modified and updated. Consequently, the accompanying papers on individual topics will be found to refer to slightly varied parameters, according to the stage at which the different problems were tackled

  16. The rings of Uranus

    Science.gov (United States)

    Elliot, J. L.; Dunham, E.; Mink, D.

    1977-01-01

    A description is given of the observation of five brief occultations of the star SAO 158687 which occurred both before and after its occultation by Uranus on March 10, 1977. The events were observed with a three-channel occultation photometer, attached to a 91-cm telescope. The observations indicate that at least five rings encircle the planet Uranus. Possible reasons for the narrowness of the Uranus rings are discussed.

  17. Improved cooler design of electric arc furnace refractory in mining industry using thermal analysis modeling and simulation

    International Nuclear Information System (INIS)

    Istadi, I.; Bindar, Y.

    2014-01-01

    Production of steel and nickel using the electric arc furnace should be focused on the intensification of energy. Improvement of energy efficiency of the most consuming facilities was achieved by improving the use of alternative energy minimization such as reducing the heat lost of hot gases, minimizing the heat radiated through refractory linings of metallurgical furnaces, and cooling the highly thermally stressed components. The refractory of electric arc furnace should be modified to achieve the best cooling system of the furnace. In this physical modeling and simulation works, four modification scenarios of wall refractory designs were simulated, i.e. refractory with basic design, refractory with deep plate coolers, refractory with extra plate coolers, and refractory with wall falling film coolers. Finally, the use of deep plate cooler and the existing waffle cooler system was considered to be the best design of efficient electric arc furnace operationally. - Highlights: • Electric arc furnace design should be focused on the intensification of energy. • Refractory of electric arc furnace were modified to achieve the best cooling system. • Four modification scenarios of the wall refractory designs were simulated. • Use of deep plate cooler and existing waffle cooler system is the best cooling

  18. Report on the status of linear drive coolers for the Department of Defense Standard Advanced Dewar Assembly (SADA)

    Science.gov (United States)

    Salazar, William

    2003-01-01

    The Standard Advanced Dewar Assembly (SADA) is the critical module in the Department of Defense (DoD) standardization effort of scanning second-generation thermal imaging systems. DoD has established a family of SADA's to address requirements for high performance (SADA I), mid-to-high performance (SADA II), and compact class (SADA III) systems. SADA's consist of the Infrared Focal Plane Array (IRFPA), Dewar, Command and Control Electronics (C&CE), and the cryogenic cooler. SADA's are used in weapons systems such as Comanche and Apache helicopters, the M1 Abrams Tank, the M2 Bradley Fighting Vehicle, the Line of Sight Antitank (LOSAT) system, the Improved Target Acquisition System (ITAS), and Javelin's Command Launch Unit (CLU). DOD has defined a family of tactical linear drive coolers in support of the family of SADA's. The Stirling linear drive cryo-coolers are utilized to cool the SADA's Infrared Focal Plane Arrays (IRFPAs) to their operating cryogenic temperatures. These linear drive coolers are required to meet strict cool-down time requirements along with lower vibration output, lower audible noise, and higher reliability than currently fielded rotary coolers. This paper will (1) outline the characteristics of each cooler, (2) present the status and results of qualification tests, and (3) present the status and test results of efforts to increase linear drive cooler reliability.

  19. Some Aspects of Ring Theory

    CERN Document Server

    Herstein, IN

    2011-01-01

    S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.

  20. Measurement of spin motions in a storage ring outside the stable polarization direction

    International Nuclear Information System (INIS)

    Akchurin, N.; McPherson, J.; Olchowski, F.; Onel, Y.; Badano, L.; Conte, M.; Bravar, A.; Penzo, A.; Hall, J.; Kreiser, H.

    1993-01-01

    Polarized, stored beams are becoming a more and more important tool in nuclear and high energy physics. In order to measure the beam polarization in a storage ring the polarization vector of the stored beam has to aim, revolution for revolution, over a period of seconds to minutes, into the same, so-called open-quote stableclose quotes, direction. In this paper measurements at the Indiana University Cooler Ring (IUCF) are described in which for the first time in a storage ring oscillations of the polarization vector around this stable direction have been measured. The existence and the dynamics of such oscillations are, for instance, important for a new proposed technique for polarizing stored hadron beams

  1. Comparison of Test Stand and Helicopter Oil Cooler Bearing Condition Indicators

    Science.gov (United States)

    Dempsey, Paula J.; Branning, Jeremy; Wade, Damiel R.; Bolander, Nathan

    2010-01-01

    The focus of this paper was to compare the performance of HUMS condition indicators (CI) when detecting a bearing fault in a test stand or on a helicopter. This study compared data from two sources: first, CI data collected from accelerometers installed on two UH-60 Black Hawk helicopters when oil cooler bearing faults occurred, along with data from helicopters with no bearing faults; and second, CI data that was collected from ten cooler bearings, healthy and faulted, that were removed from fielded helicopters and installed in a test stand. A method using Receiver Operating Characteristic (ROC) curves to compare CI performance was demonstrated. Results indicated the bearing energy CI responded differently for the helicopter and the test stand. Future research is required if test stand data is to be used validate condition indicator performance on a helicopter.

  2. Numerical Studies of the Friction Force for the RHIC Electron Cooler

    CERN Document Server

    Fedotov, Alexei V; Ben-Zvi, Ilan; Bruhwiler, David L; Busby, Richard; Litvinenko, Vladimir N; Schoessow, Paul

    2005-01-01

    Accurate calculation of electron cooling times requires an accurate description of the dynamical friction force. The proposed RHIC cooler will require ~55 MeV electrons, which must be obtained from an RF linac, leading to very high transverse electron temperatures. A strong solenoid will be used to magnetize the electrons and suppress the transverse temperature, but the achievable magnetized cooling logarithm will not be large. Available formulas for magnetized dynamical friction are derived in the logarithmic approximation, which is questionable in this regime. In this paper, we explore the magnetized friction force for parameters of the RHIC cooler, using the VORPAL code.* VORPAL can simulate dynamical friction and diffusion coefficients directly from first principles.** Various aspects of the friction force, such as dependence on magnetic field, scaling with ion charge number and others, are addressed for the problem of high-energy electron cooling in the RHIC regime.

  3. Heat Exchange and Fouling Analysis on a Set of Hydrogen Sulphide Gas Coolers

    Directory of Open Access Journals (Sweden)

    Andrés Adrian Sánchez-Escalona

    2017-07-01

    Full Text Available The sulphide acid coolers are tube and shell jacketed heat exchangers designed to cool down the produced gas from 416,15 K to 310,15 K in addition to separate the sulphur carried over by the outlet gas from the reactor tower. The investigation was carried out by applying the passive experimentation process in an online cooler set in order to determine the heat transfer rates and fouling based on heat resistance. It was corroborated that the operation of this equipment outside design parameters increases outlet gas temperature and liquid sulphur carryovers. Efficiency loss is caused by fouling elements in the fluid, which results in changes in the overall heat transfer rate. The linear tendency of the fouling heat resistance based on time for three gas flowrates.

  4. Optimization of multiple-module thermoelectric coolers using artificial-intelligence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chen, K. [University of Utah (United States). Dept. of Mechanical Engineering; Lin, G.T. [National Taiwan University of Science and Technology, Taipei (China). Dept. of Mechanical Engineering

    2002-07-01

    Genetic algorithm (GA) and simulated annealing (SA) methods were employed to optimize the current distribution of a cooler made up of a large number of thermoelectric (TE) modules. The TE modules were grouped into several clusters in the flow direction, and the electric currents supplied to different clusters were adjusted separately to achieve maximum energy efficiency or minimum refrigeration temperature for different,operating conditions and cooling requirements. Optimization results based on the design parameters of a large TE cooler showed considerable improvements in energy efficiency and refrigeration temperature when compared to the results of uniform current for the parallel-flow arrangement. On the other hand, results of the counter-flow arrangement showed only slight differences between uniform- and non-uniform-current optimizations. The optimization results of GA and SA were very close to each other. SA converged faster and was more computationally economical than GA for TE system optimization. (author)

  5. RFQ beam cooler and buncher for collinear laser spectroscopy of rare isotopes

    Science.gov (United States)

    Barquest, B. R.; Bollen, G.; Mantica, P. F.; Minamisono, K.; Ringle, R.; Schwarz, S.; Sumithrarachchi, C. S.

    2017-09-01

    A radiofrequency quadrupole (RFQ) ion beam cooler and buncher has been developed to deliver bunched beams with low transverse emittance, energy spread, and time spread to the BECOLA collinear laser spectroscopy system at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The beam cooler and buncher contains new features which enhance performance, especially for high count rate beams, as well as simplifying construction, maintenance, and operation. The transverse emittance, energy spread, and time spread of the bunched beam, as well as buncher efficiency are reported, showcasing the capabilities of the BECOLA facility to perform collinear laser spectroscopy measurements with bunched rare isotope beams at NSCL and at the future Facility for Rare Isotope Beams (FRIB).

  6. Heat transfer and evaporative cooling in the function of pot-in-pot coolers

    Science.gov (United States)

    Chemin, Arsène; Levy Dit Vehel, Victor; Caussarieu, Aude; Plihon, Nicolas; Taberlet, Nicolas

    2018-03-01

    A pot-in-pot cooler is an affordable electricity-free refrigerator which uses the latent heat of vaporization of water to maintain a low temperature inside an inner compartment. In this article, we experimentally investigate the influence of the main physical parameters in model pot-in-pot coolers. The effect of the wind on the evaporation rate of the cooling fluid is studied in model experiments while the influence of the fluid properties (thermal conductivity, specific heat, and latent heat) is elucidated using a variety of cooling fluids (water, ethanol, and ether). A model based on a simplified heat conduction equation is proposed and is shown to be in good quantitative agreement with the experimental measurements.

  7. Evaluation of heat exchange performance for primary pressurized water cooler in HTTR

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Nakagawa, Shigeaki

    2006-01-01

    In High Temperature Engineering Test Reactor (HTTR), the rated thermal power of 30 MW, the generated heat at reactor core is finally dissipated at the air-cooler by way of the heat exchangers of the primary cooling system, such as the primary pressurized water cooler (PPWC) and the intermediate heat exchanger (IHX). The heat exchangers in the primary cooling system are required the heat exchange performance to remove reactor generated heat 30 MW under the condition of reactor coolant outlet temperature 850degC/950degC. Therefore, the heat exchanges are required to satisfy the design criteria of heat exchange performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the PPWC in the main cooling system was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that PPWC has the required heat exchange performance in the design. (author)

  8. Evaluation of heat exchange performance for secondary pressurized water cooler in HTTR

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Watanabe, Syuji; Saikusa, Akio; Oyama, Sunao; Nemoto, Takahiro; Hamamoto, Shinpei; Shinohara, Masanori; Isozaki, Minoru; Nakagawa, Shigeaki

    2006-02-01

    In High Temperature Engineering Test Reactor (HTTR), the rated thermal power of 30MW, the generated heat at reactor core is finally dissipated at the air-cooler by way of the heat exchangers of the primary cooling system, such as the intermediate heat exchanger (IHX) and the secondary pressurized water cooler (SPWC). The heat exchangers in the main cooling system are required the heat exchange performance to remove the reactor-generated-heat of 30MW under the condition of reactor coolant outlet temperature of 850degC/950degC. Therefore, the heat exchanges are required to satisfy the design criteria of heat exchange performance. In this report, heat exchange performance of the SPWC in the main cooling system was evaluated with the rise-to-power-up test and the in-service operation data. Moreover, evaluated value is compared with designed one, it is confirmed that the SPWC has required heat exchange performance. (author)

  9. Forecast of winter performances of dry coolers with fin tubes; Voorspelling winterprestaties droge koelers met ribbenbuizen

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Bing [Shanghai DFYH Tech Services Co. Ltd, Shanghai (China); Wang, Xichun [Arup, Shanghai (China); Luscuere, P.G. [Faculteit Bouwkunde, Technische Universiteit Delft, Delft (Netherlands)

    2011-01-15

    A mathematical model is presented to predict the behaviors of dry coolers by considering the condensing and frosting. It employs one-dimensional transient finite differential formulation with variation of the frost density and thickness. The model is validated by experiments and predicts the heat transfer performance with an accuracy within 2.19%. It is helpful for the operation of dry coolers in winter. [Dutch] In dit artikel wordt een wiskundig model gepresenteerd, waarmee voortschrijdende condens- en ijsvorming op warmteoverdrachtsoppervlakken kunnen worden voorspeld aan de hand van de gevormde condens- en ijslagen. Het model maakt gebruik van eendimensionale transiente formuleringen op basis van een techniek voor lokale uitmiddeling. Hierbij wordt rekening gehouden met de varierende dichtheid en dikte van de ijslaag. Validatie van het model heeft plaatsgevonden door de resultaten te vergelijken met proefgegevens van de fabrikant van de droge koeler.

  10. NUMERICAL STUDIES OF THE FRICTION FORCE FOR THE RHIC ELECTRON COOLER

    International Nuclear Information System (INIS)

    FEDOTOV, A.V.; BEN-ZVI, I.; LITVINENKO, V.

    2005-01-01

    Accurate calculation of electron cooling times requires an accurate description of the dynamical friction force. The proposed RHIC cooler will require ∼55 MeV electrons, which must be obtained from an RF linac, leading to very high transverse electron temperatures. A strong solenoid will be used to magnetize the electrons and suppress the transverse temperature, but the achievable magnetized cooling logarithm will not be large. In this paper, we explore the magnetized friction force for parameters of the RHIC cooler, using the VORPAL code [l]. VORPAL can simulate dynamical friction and diffusion coefficients directly from first principles [2]. Various aspects of the fiction force are addressed for the problem of high-energy electron cooling in the RHIC regime

  11. Ring correlations in random networks.

    Science.gov (United States)

    Sadjadi, Mahdi; Thorpe, M F

    2016-12-01

    We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

  12. Topology optimisation of passive coolers for light-emitting diode lamps

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    2015-01-01

    This work applies topology optimisation to the design of passive coolers for light-emitting diode (LED) lamps. The heat sinks are cooled by the natural convection currents arising from the temperature difference between the LED lamp and the surrounding air. A large scale parallel computational....... The optimisation results show interesting features that are currently being incorporated into industrial designs for enhanced passive cooling abilities....

  13. Cooler reflective pavements give benefits beyond energy savings: durability and illumination

    International Nuclear Information System (INIS)

    Pomerantz, Melvin; Akbari, Hashem; Harvey, John T.

    2000-01-01

    City streets are usually paved with asphalt concrete because this material gives good service and is relatively inexpensive to construct and maintain. We show that making asphalt pavements cooler, by increasing their reflection of sunlight, may lead to longer lifetime of the pavement, lower initial costs of the asphalt binder, and savings on street lighting and signs. Excessive glare due to the whiter surface is not likely to be a problem

  14. 3-D thermal hydraulic analysis of transient heat removal from fast reactor core using immersion coolers

    International Nuclear Information System (INIS)

    Chvetsov, I.; Volkov, A.

    2000-01-01

    For advanced fast reactors (EFR, BN-600M, BN-1600, CEFR) the special complementary loop is envisaged in order to ensure the decay heat removal from the core in the case of LOF accidents. This complementary loop includes immersion coolers that are located in the hot reactor plenum. To analyze the transient process in the reactor when immersion coolers come into operation one needs to involve 3-D thermal hydraulics code. Furthermore sometimes the problem becomes more complicated due to necessity of simulation of the thermal hydraulics processes into the core interwrapper space. For example on BN-600M and CEFR reactors it is supposed to ensure the effective removal of decay heat from core subassemblies by specially arranged internal circulation circuit: 'inter-wrapper space'. For thermal hydraulics analysis of the transients in the core and in the whole reactor including hot plenum with immersion coolers and considering heat and mass exchange between the main sodium flow and sodium that moves in the inter-wrapper space the code GRIFIC (the version of GRIF code family) was developed in IPPE. GRIFIC code was tested on experimental data obtained on RAMONA rig under conditions simulating decay heat removal of a reactor with the use of immersion coolers. Comparison has been made of calculated and experimental result, such as integral characteristics (flow rate through the core and water temperature at the core inlet and outlet) and the local temperatures (at thermocouple location) as well. In order to show the capabilities of the code some results of the transient analysis of heat removal from the core of BN-600M - type reactor under loss-of-flow accident are presented. (author)

  15. Mathematical modeling of processes of heat and mass transfer in channels of water evaporating coolers

    Science.gov (United States)

    Gulevsky, V. A.; Ryazantsev, A. A.; Nikulichev, A. A.; Menzhulova, A. S.

    2018-05-01

    The variety of cooling systems is dictated by a wide range of demands placed on them. This is the price, operating costs, quality of work, ecological safety, etc. These requirements in a positive sense are put into correspondence by water evaporating plate coolers. Currently, their widespread use is limited by a lack of theoretical base. To solve this problem, the best method is mathematical modeling.

  16. Design of passive coolers for light-emitting diode lamps using topology optimisation

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Sigmund, Ole; Meyer, Knud Erik

    2018-01-01

    Topology optimised designs for passive cooling of light-emitting diode (LED) lamps are investigated through extensive numerical parameter studies. The designs are optimised for either horizontal or vertical orientations and are compared to a lattice-fin design as well as a simple parameter......, while maintaining low sensitivity to orientation. Furthermore, they exhibit several defining features and provide insight and general guidelines for the design of passive coolers for LED lamps....

  17. Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    Science.gov (United States)

    Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

    2010-10-01

    Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  18. The Rings of Saturn

    Science.gov (United States)

    Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.

    2018-03-01

    One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the

  19. Characterization of a thermoelectric cooler based thermal management system under different operating conditions

    International Nuclear Information System (INIS)

    Russel, M.K.; Ewing, D.; Ching, C.Y.

    2013-01-01

    The performance of a thermoelectric cooler (TEC) based thermal management system for an electronic packaging design that operates under a range of ambient conditions and system loads is examined using a standard model for the TEC and a thermal resistance network for the other components. Experiments were performed and it was found that the model predictions were in good agreement with the experimental results. An operating envelope is developed to characterize the TEC based thermal management system for peak and off peak operating conditions. Parametric studies were performed to analyze the effect of the number of TEC module(s) in the system, geometric factor of the thermo-elements and the cold to hot side thermal resistances on the system performance. The results showed that there is a tradeoff between the extent of off peak heat fluxes and ambient temperatures when the system can be operated at a low power penalty region and the maximum capacity of the system. - Highlights: ► A model was developed for thermal management systems using thermoelectric coolers. ► Model predictions were in good agreement with experimental results. ► An operating envelope was developed for peak and off peak conditions. ► The effect of the number of thermoelectric coolers on the system was determined.

  20. Metal foams as gas coolers for exhaust gas recirculation systems subjected to particulate fouling

    International Nuclear Information System (INIS)

    Hooman, K.; Malayeri, M.R.

    2016-01-01

    Highlights: • Fouling of metal foam heat exchangers as EGR gas coolers is tested. • An optimal design was inferred based on the generated data. • A simple cleaning technique was suggested and evaluated. - Abstract: This paper presents experimental results indicating the benefits and challenges associated with the use of metal foams as Exhaust Gas Recirculation (EGR) coolers. Fouling of such heat exchangers is a critical issue and, as such, special attention has been paid to address this very issue in the present study where a soot generator has been employed to simulate the engine running condition. Effects of aluminium foam PPI and height as well as gas velocity are investigated. It has been noted that proper design of the foam can lead to significantly higher heat transfer rate and reasonable pressure drop compared to no-foam cases. More interestingly, it is demonstrated that the foams can be cleaned easily without relying on expensive cleaning techniques. Using simple brush-cleaning, the foams can be reused as EGR gas coolers with a performance penalty of only 17% (compared to a new or clean foam).

  1. Numerical modeling of the thermoelectric cooler with a complementary equation for heat circulation in air gaps

    Science.gov (United States)

    Fang, En; Wu, Xiaojie; Yu, Yuesen; Xiu, Junrui

    2017-03-01

    In this paper, a numerical model is developed by combining thermodynamics with heat transfer theory. Taking inner and external multi-irreversibility into account, it is with a complementary equation for heat circulation in air gaps of a steady cooling system with commercial thermoelectric modules operating in refrigeration mode. With two modes concerned, the equation presents the heat flowing through air gaps which forms heat circulations between both sides of thermoelectric coolers (TECs). In numerical modelling, a TEC is separated as two temperature controlled constant heat flux reservoirs in a thermal resistance network. In order to obtain the parameter values, an experimental apparatus with a commercial thermoelectric cooler was built to characterize the performance of a TEC with heat source and sink assembly. At constant power dissipation, steady temperatures of heat source and both sides of the thermoelectric cooler were compared with those in a standard numerical model. The method displayed that the relationship between Φf and the ratio Φ_{c}'/Φ_{c} was linear as expected. Then, for verifying the accuracy of proposed numerical model, the data in another system were recorded. It is evident that the experimental results are in good agreement with simulation(proposed model) data at different heat transfer rates. The error is small and mainly results from the instabilities of thermal resistances with temperature change and heat flux, heat loss of the device vertical surfaces and measurements.

  2. Comparison of desiccant air conditioning systems with different indirect evaporative air coolers

    International Nuclear Information System (INIS)

    Pandelidis, Demis; Anisimov, Sergey; Worek, William M.; Drąg, Paweł

    2016-01-01

    Highlights: • A numerical study of desiccant air conditioning systems is presented. • The ε-NTU model is used for the analysis. • Different arrangements of the desiccant systems were compared. • The systems were compared under different operating conditions. - Abstract: This paper presents a numerical analysis of three desiccant air-conditioning systems equipped with different indirect evaporative air coolers: (1) the cross-flow Maisotsenko cycle heat and mass exchanger (HMX), (2) the regenerative counter-flow Maisotsenko cycle heat and mass exchanger and (3) the standard cross-flow evaporative air cooler. To analyze the desiccant wheel and the indirect evaporative air coolers, the modified ε-NTU-model was used. The simulations were performed under assumption that the desiccant wheel is regenerated with air heated to relatively low temperature values (50–60 °C), which can be produced with solar panels in typical moderate climatic conditions. It was established that the main advantage of the presented solutions is that they can provide comfort conditions even with less effective dehumidification. The different systems were compared under variable selected operational factors (i.e. inlet air temperature, humidity and regeneration air temperature). The analysis allowed establishing the advantages and disadvantages of presented solutions and allowed estimating their application potential.

  3. BERKELEY: ALS ring

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-06-15

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  4. Compressible Vortex Ring

    Science.gov (United States)

    Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

    1999-11-01

    The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.

  5. BERKELEY: ALS ring

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  6. Atomic and molecular physics with ion storage rings

    International Nuclear Information System (INIS)

    Larsson, M.

    1995-01-01

    Advances in ion-source, accelerator and beam-cooling technology have made it possible to produce high-quality beams of atomic ions in arbitrary charged states as well as molecular and cluster ions are internally cold. Ion beams of low emittance and narrow momentum spread are obtained in a new generation of ion storage-cooler rings dedicated to atomic and molecular physics. The long storage times (∼ 5 s ≤ τ ≤ days) allow the study of very slow processes occurring in charged (positive and negative) atoms, molecules and clusters. Interactions of ions with electrons and/or photons can be studied by merging the stored ion beam with electron and laser beams. The physics of storage rings spans particles having a charge-to-mass ratio ranging from 60 + and C 70 + ) to 0.4 - 1.0 (H + , D + , He 2+ , ..., U 92+ ) and collision processes ranging from <1 meV to ∼ 70 GeV. It incorporates, in addition to atomic and molecular physics, tests of fundamental physics theories and atomic physics bordering on nuclear and chemical physics. This exciting development concerning ion storage rings has taken place within the last five to six years. (author)

  7. Almost ring theory

    CERN Document Server

    2003-01-01

    This book develops thorough and complete foundations for the method of almost etale extensions, which is at the basis of Faltings' approach to p-adic Hodge theory. The central notion is that of an "almost ring". Almost rings are the commutative unitary monoids in a tensor category obtained as a quotient V-Mod/S of the category V-Mod of modules over a fixed ring V; the subcategory S consists of all modules annihilated by a fixed ideal m of V, satisfying certain natural conditions. The reader is assumed to be familiar with general categorical notions, some basic commutative algebra and some advanced homological algebra (derived categories, simplicial methods). Apart from these general prerequisites, the text is as self-contained as possible. One novel feature of the book - compared with Faltings' earlier treatment - is the systematic exploitation of the cotangent complex, especially for the study of deformations of almost algebras.

  8. Emittance measurements in low energy ion storage rings

    Science.gov (United States)

    Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

    2018-07-01

    The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

  9. Compact electron storage rings

    International Nuclear Information System (INIS)

    Williams, G.P.

    1987-01-01

    There have been many recent developments in the area of compact storage rings. Such rings would have critical wavelengths of typically 10 A, achieved with beam energies of several hundreds of MeV and superconducting dipole fields of around 5 Tesla. Although the primary motivation for progress in this area is that of commercial x-ray lithography, such sources might be an attractive source for college campuses to operate. They would be useful for many programs in materials science, solid state, x-ray microscopy and other biological areas. We discuss the properties of such sources and review developments around the world, primarily in the USA, japan and W. Germany

  10. The covariant chiral ring

    Energy Technology Data Exchange (ETDEWEB)

    Bourget, Antoine; Troost, Jan [Laboratoire de Physique Théorique, École Normale Supérieure, 24 rue Lhomond, 75005 Paris (France)

    2016-03-23

    We construct a covariant generating function for the spectrum of chiral primaries of symmetric orbifold conformal field theories with N=(4,4) supersymmetry in two dimensions. For seed target spaces K3 and T{sup 4}, the generating functions capture the SO(21) and SO(5) representation theoretic content of the chiral ring respectively. Via string dualities, we relate the transformation properties of the chiral ring under these isometries of the moduli space to the Lorentz covariance of perturbative string partition functions in flat space.

  11. Vortex and source rings

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    The velocity field, vector potential and velocity gradient of a vortex ring is derived in this chapter. The Biot-Savart law for the vector potential and velocity is expressed in a first section. Then, the flow is derived at specific locations: on the axis, near the axis and in the far field where...... the analogy to a doublet field is made. The following section derive the value of the vector potential and velocity field in the full domain. The expression for the velocity gradient is also provided since it may be relevant in a simulation with vortex particles and vortex rings. Most of this chapter...

  12. The Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.

    1975-09-01

    The structure of the Saturnian rings is traditionally believed to be due to resonances caused by Mimas (and possibly other satellites). It is shown that both theoretical and observational evidence rule out this interpretation. The increased observational accuracy on one hand and the increased understanding of the cosmogonic processes on the other makes it possible to explain the structure of the ring system as a product of condensation from a partially corotating plasma. In certain respects the agreement between theory and observations is about 1%. (Auth.)

  13. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  14. Simulation of spin dynamics to measure electric dipole moments in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, Marcel; Lehrach, Andreas [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Kernphysik; Collaboration: JEDI-Collaboration

    2013-07-01

    CP violation in the baryon sector, which is predicted by the Standard Model of Particle Physics, is too small to explain the matter and antimatter asymmetry in our universe. Permanent Electric Dipole Moments (EDMs) violate both P and T symmetries and are therefore, through the CPT theorem, also CP violating. No direct EDM measurements for protons, deuterons and light nuclei have been performed up to now. The JEDI collaboration at Forschungszentrum Juelich (FZJ) and the BNL-EDM collaboration at Brookhaven National Laboratory (BNL) pursue the goal to measure the EDMs of these particles in dedicated storage rings. Therefore different approaches are studied to reach an ultimate sensitivity of 10{sup -29} e.cm. A first direct measurement of the proton and deuteron EDM at a sensitivity level of 10{sup -24} e.cm will be performed in the existing conventional storage ring at FZJ, the Cooler Synchrotron COSY. Particle tracking simulations to explore the motion-correlated spin dynamics are a crucial part of feasibility studies of the planned storage ring EDM experiments. In a first step, a benchmarking of simulation codes with measurements at the Cooler Synchrotron COSY is performed.

  15. Fusion rings and fusion ideals

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...

  16. Flushing Ring for EDM

    Science.gov (United States)

    Earwood, L.

    1985-01-01

    Removing debris more quickly lowers cutting time. Operation, cutting oil and pressurized air supplied to ring placed around workpiece. Air forces oil through small holes and agitates oil as it flows over workpiece. High flow rate and agitation dislodge and remove debris. Electrical discharge removes material from workpiece faster.

  17. Sector ring accelerator ''RESATRON''

    International Nuclear Information System (INIS)

    Schwabe, E.

    1980-01-01

    Project of sector ring accelerator RESATRON is described. The curiosity of this accelerator is the second cycle of acceleration of the beam after stripping it on the foil. In such an accelerator heavy ions with a different ratio Z to A can be accelerated. (S.B.)

  18. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B

    1992-01-01

    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation...

  19. SXLS storage ring design

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    X-ray lithography has emerged as a strong candidate to meet the demands of ever finer linewidths on integrated circuits, particularly for linewidths less than .25 microns. Proximity printing X-ray lithography makes use of soft X-rays to shadow print an image of a mask onto a semiconductor wafer to produce integrated circuits. To generate the required X-rays in sufficient quantities to make commercial production viable, electron storage rings have been proposed as the soft X-ray sources. Existing storage rings have been used to do the initial development work and the success of these efforts has led the lithographers to request that new rings be constructed that are dedicated to X-ray lithography. As a result of a series of workshops held at BNL [10.3] which were attended by both semiconductor and accelerator scientists, the following set of zeroth order specifications' on the light and electron beam of a storage ring for X-ray lithography were developed: critical wavelength of light: λ c = 6 to 10 angstroms, white light power: P = 0.25 to 2.5 watts/mrad, horizontal collection angle per port: θ = 10 to 50 mrad, electron beam sizes: σ x ∼ σ y y ' < 1 mrad

  20. Ring magnetron ionizer

    International Nuclear Information System (INIS)

    Alessi, J.G.

    1986-01-01

    A ring magnetron D - charge exchange ionizer has been built and tested. An H - current of 500 μA was extracted with an estimated H 0 density in the ionizer of 10 12 cm -3 . This exceeds the performance of ionizers presently in use on polarized H - sources. The ionizer will soon be tested with a polarized atomic beam

  1. Algebras, rings and modules

    CERN Document Server

    Hazewinkel, Michiel; Kirichenko, V V

    Provides both the classical aspects of the theory of groups and their representations as well as a general introduction to the modern theory of representations, including the representations of quivers and finite partially ordered sets. This volume provides the theory of semiprime Noetherian semiperfect and semidistributive rings.

  2. Lattices for antiproton rings

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

    After a description of the constraints imposed by the cooling of Antiprotons on the lattice of the rings, the reasons which motivate the shape and the structure of these machines are surveyed. Linear and non-linear beam optics properties are treated with a special amplification to the Antiproton Accumulator. (orig.)

  3. Propellers in Saturn's rings

    Science.gov (United States)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B ring. The gap moves at Kepler speed appropriate for its radial location. Radial offsets of the gap locations in UVIS occultations are consistent with an asymmetric propeller shape. The asymmetry of the observed shape is most likely a consequence of the strong surface mass density gradient, as the feature is located at an edge between

  4. FUZZY RINGS AND ITS PROPERTIES

    Directory of Open Access Journals (Sweden)

    Karyati Karyati

    2017-01-01

      One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level  and strong level  as well as image and pre-image homomorphism fuzzy ring.   Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring

  5. Inorganic glass ceramic slip rings

    Science.gov (United States)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  6. Uniquely Strongly Clean Group Rings

    Institute of Scientific and Technical Information of China (English)

    WANG XIU-LAN

    2012-01-01

    A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

  7. Thermal energy analysis of a lime production process: Rotary kiln, preheater and cooler

    International Nuclear Information System (INIS)

    Shahin, Hamed; Hassanpour, Saeid; Saboonchi, Ahmad

    2016-01-01

    Highlights: • The integrated model for lime production unit which includes cooler, preheater and rotary kiln is developed. • The effect of residence time in each section on efficiency is investigated. • Influence of material feed rate and excess air on specific fuel consumption is analyzed. • The significant effect of particle size on efficiency and specific fuel consumption is shown. - Abstract: In this paper, thermal energy analysis of three zones of a lime production process, which are preheater, rotary kiln and cooler, is performed. In order to perform a proper quantitative estimation, the system was modeled using energy balance equations including coupled heat transfer and chemical reaction mechanisms. A mathematical model was developed, and consequently, the thermal and chemical behavior of limestone was investigated. The model was verified using empirical data. After model confirmation, the variation of Specific Fuel Consumption (SFC) versus production rate was predicted and the optimum condition was determined. Subsequently, fuel consumption was calculated regarding to altered residence time inside each zone of lime production process, for a constant output. Results indicate that increasing the residence time inside each zone of lime production process, will enhance thermal efficiency and saves fuel consumption. Relative enhancement will be the same for different sizes of limestone. It was found that a 10-min increase in material residence time inside the preheater or rotary kiln can reduce fuel consumption by around two percent. Whereas, a 5-min increase in material residence time inside the cooler would be enough to obtain a similar result. Finally, the ratio of air-to-fuel and production rate are changed in such a way that the same product is achieved. The model predicts that lowering excess air from 15% to 10% leads to a 2.5% reduction of Specific Fuel Consumption (SFC).

  8. Operation of a pond-cooler: the case of Berezovskaya GRES-1

    Science.gov (United States)

    Morozova, O. G.; Kamoza, T. L.; Koyupchenko, I. N.; Savelyev, A. S.; Pen, R. Z.; Veselkova, N. S.; Kudryavtsev, M. D.

    2017-08-01

    Pond-coolers at heat and nuclear power stations are natural-technological systems, so the program of their monitoring should include the effect made by the SRPS (state regional power station) on the pond ecosystem, including thermal discharge of cooling water. The objectives of this study were development and implementation of a monitoring program for the cooling pond of Berezovskaya SRPS-1 on the chemical and biological water quality indicators and identification of patterns of the thermal and hydrochemical regime when operating the progressive power plant (from 1996 to 2015). The quality of the cooling water of the pond-cooler BGRES-1 was studied under full-scale conditions by selecting and analyzing the water samples of the pond in accordance with the principles of complexity, systematic observation, and consistency of timing their conduct with the characteristic hydrological phases. Processing of the obtained array of monitoring data by methods of mathematical statistics makes it possible to identify the main factors affecting the water quality of the pond. The data on water quality obtained during their monitoring and mathematical processing over a long time interval are the scientific basis for forecasting the ecological state of the pond, which is necessary to economically ensure the efficient energy production and safety of water use. Recommendations proposed by these authors, including those partially already implemented, have been to prevent the development of eutrophication processes in the pond-cooler: the construction of a dam that cuts off the main peat massif and cleaning the river banks forming the cooling pond.

  9. Ring closure in actin polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Supurna, E-mail: supurna@rri.res.in [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)

    2017-03-18

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.

  10. The Next Generation Sky Survey and the Quest for Cooler Brown Dwarfs

    OpenAIRE

    Kirkpatrick, J. Davy

    2002-01-01

    The Next Generation Sky Survey (NGSS) is a proposed NASA MIDEX mission to map the entire sky in four infrared bandpasses - 3.5, 4.7, 12, and 23 um. The seven-month mission will use a 50-cm telescope and four-channel imager to survey the sky from a circular orbit above the Earth. Expected sensitivities will be half a million times that of COBE/DIRBE at 3.5 and 4.7 um and a thousand times that of IRAS at 12 and 23 um. NGSS will be particularly sensitive to brown dwarfs cooler than those present...

  11. A beam position monitor system for electron cooler in HIRFL-CSR

    International Nuclear Information System (INIS)

    Li Guohong; Li Jie; Yang Xiaodong; Yan Tailai; Ma Xiaoming

    2010-01-01

    The efficient electron cooling requires that the ion beam and electron beam are parallel and overlapped. In order to measure the positions of ion beam and electron beam simultaneously, a beam position monitor system is developed for the HIRFL-CSR electron cooler device, which probe consists of four capacitive cylinder linear-cut poles. One can get the both beam positions from the picking up signals of four poles by using Fourier transform (FFT) method. The measurement results show that the beam position monitor system is accurate. This system is suitable for investigating the relation between electron cooling processing and the angle of ion beam and electron beam. (authors)

  12. Studying the operational regimes of air-radiator coolers at the Bilibin NPP

    International Nuclear Information System (INIS)

    Gutsev, D.F.; Dembovskij, A.V.; Kuznetsov, R.K.; Lukashenko, Eh.M.; Morozov, S.K.; Soldatov, G.E.

    1985-01-01

    Results of experimental and calculational-theoretical studies of operational regimes of airradiator coolers at the Bilibin NPP are set out. For the first time dry fan towers are used there under the Far North conditions. Operational experience of the Forgo cooling towers under the above conditions is given. The mathematical model of monstationary heat transfer in a pipe heat exchanger ribbed with perforated plates is worked out for numerical analysis of the tower operational regimes. The results of studies point out the ways for improvement of the cooling towers and their operational conditions

  13. Design of low energy ring(s)

    CERN Document Server

    Lachaize, Antoine

    During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times [1], [2], [3].General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 [4]. More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS [5], [6], [7].Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injectio...

  14. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2012-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...

  15. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  16. A numerical study on the usage of phase change material (PCM) to prolong compressor off period in a beverage cooler

    International Nuclear Information System (INIS)

    Ezan, Mehmet Akif; Ozcan Doganay, Esra; Yavuz, Fazil Erinc; Tavman, Ismail Hakkı

    2017-01-01

    Highlights: • A 3D transient model is developed in a commercial CFD solver for vertical beverage cooler with PCM. • PCM slab is directly contacted with the airflow. • Regarding the run-time ratio best performance is achieved with 6 mm PCM slab. • Due to thermal inertia within the PCM domain, the VBC preserves its temperature for a long time. - Abstract: This study numerically investigates the influence of integration of a phase change material (PCM) slab inside a vertical beverage cooler (VBC) on the energy consumption, the thermal stability and flow characteristics of air inside the cooler. The PCM, water, slab is placed on the rear side of the flat plate roll bond evaporator with five different thicknesses, such as 2, 4, 6, 8, and 10 mm. In the current work, transient numerical analyses are performed with ANSYS-FLUENT software for an empty cooler. To simulate the on/off controller of the cooling system a dedicated user-defined-function (UDF) is implemented in the software. Unlike the counterparts in the recent literature, instead of reducing the problem into a 1D or 2D lumped models a three-dimensional cooler domain is simulated in a commercial CFD solver. The predictions are compared with the experimental measurement for the cooler without PCM regarding the transient variations of the mean temperatures of evaporator surface and the indoor air. Consequently, the parametric set of analyses deduced that the PCM integration into the cooler enhances the cooling performance of the VBC by prolonging compressor off duration. Moreover, during the compressor off time, PCM preserves the air temperature inside the refrigerated space in the desired range by limiting the sudden temperature increments.

  17. Ring Confidential Transactions

    Directory of Open Access Journals (Sweden)

    Shen Noether

    2016-12-01

    Full Text Available This article introduces a method of hiding transaction amounts in the strongly decentralized anonymous cryptocurrency Monero. Similar to Bitcoin, Monero is a cryptocurrency which is distributed through a proof-of-work “mining” process having no central party or trusted setup. The original Monero protocol was based on CryptoNote, which uses ring signatures and one-time keys to hide the destination and origin of transactions. Recently the technique of using a commitment scheme to hide the amount of a transaction has been discussed and implemented by Bitcoin Core developer Gregory Maxwell. In this article, a new type of ring signature, A Multilayered Linkable Spontaneous Anonymous Group signature is described which allows one to include a Pedersen Commitment in a ring signature. This construction results in a digital currency with hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation. The author would like to note that early drafts of this were publicized in the Monero Community and on the #bitcoin-wizards IRC channel. Blockchain hashed drafts are available showing that this work was started in Summer 2015, and completed in early October 2015. An eprint is also available at http://eprint.iacr.org/2015/1098.

  18. Development of a new RFQ beam cooler and buncher for the CANREB project at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Barquest, B.R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Bale, J.C.; Dilling, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); UBC Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Gwinner, G. [University of Manitoba, Department of Physics and Astronomy, Allen Building, Winnipeg, MB R3T 2N2 (Canada); Kanungo, R. [Saint Mary’s University, Astronomy and Physics Department, 923 Robie Street, Halifax, NS B3H 3C3 (Canada); Krücken, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); UBC Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Pearson, M.R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada)

    2016-06-01

    A new radiofrequency quadrupole (RFQ) based ion beam cooler and buncher is under development for the CANadian Rare-isotope facility with Electron Beam ion source (CANREB) project at TRIUMF. The CANREB project requires an RFQ buncher that will efficiently accept continuous beams of rare isotopes from either the Advanced Rare IsotopE Laboratory (ARIEL) or Isotope Separator and ACcelerator (ISAC) target by way of a high resolution magnetic spectrometer, with energies up to 60 keV and deliver bunched beams to an electron beam ion source (EBIS) for charge breeding. The energy of the bunched beam delivered to the EBIS will be adjustable to match the requirements of the existing post acceleration infrastructure. The CANREB RFQ incorporates design considerations to facilitate ease of use over a wide range of ion masses, and is intended to accommodate incident beam rates as high as 10{sup 8} pps, delivering beam bunches at 100 Hz. An overview of the CANREB RFQ design concept will be presented, informed by results from both ion optical simulations as well as commissioning efforts with other beam cooler and buncher devices. Simulation results indicate that the design is well suited to deliver high quality bunched beams with high efficiency with as many as 10{sup 6} ions per bunch.

  19. Synthetical optimization of hydraulic radius and acoustic field for thermoacoustic cooler

    International Nuclear Information System (INIS)

    Kang Huifang; Li Qing; Zhou Gang

    2009-01-01

    It is well known that the acoustic field and the hydraulic radius of the regenerator play key roles in thermoacoustic processes. The optimization of hydraulic radius strongly depends on the acoustic field in the regenerator. This paper investigates the synthetical optimization of hydraulic radius and acoustic field which is characterized by the ratio of the traveling wave component to the standing wave component. In this paper, we discussed the heat flux, cooling power, temperature gradient and coefficient of performance of thermoacoustic cooler with different combinations of hydraulic radiuses and acoustic fields. The calculation results show that, in the cooler's regenerator, due to the acoustic wave, the heat is transferred towards the pressure antinodes in the pure standing wave, while the heat is transferred in the opposite direction of the wave propagation in the pure traveling wave. The better working condition for the regenerator appears in the traveling wave phase region of the like-standing wave, where the directions of the heat transfer by traveling wave component and standing wave component are the same. Otherwise, the small hydraulic radius is not a good choice for acoustic field with excessively high ratio of traveling wave, and the small hydraulic radius is only needed by the traveling wave phase region of like-standing wave.

  20. General Approach for Composite Thermoelectric Systems with Thermal Coupling: The Case of a Dual Thermoelectric Cooler

    Directory of Open Access Journals (Sweden)

    Cuautli Yanehowi Flores-Niño

    2015-06-01

    Full Text Available In this work, we show a general approach for inhomogeneous composite thermoelectric systems, and as an illustrative case, we consider a dual thermoelectric cooler. This composite cooler consists of two thermoelectric modules (TEMs connected thermally in parallel and electrically in series. Each TEM has different thermoelectric (TE properties, namely thermal conductance, electrical resistance and the Seebeck coefficient. The system is coupled by thermal conductances to heat reservoirs. The proposed approach consists of derivation of the dimensionless thermoelectric properties for the whole system. Thus, we obtain an equivalent figure of merit whose impact and meaning is discussed. We make use of dimensionless equations to study the impact of the thermal conductance matching on the cooling capacity and the coefficient of the performance of the system. The equivalent thermoelectric properties derived with our formalism include the external conductances and all intrinsic thermoelectric properties of each component of the system. Our proposed approach permits us changing the thermoelectric parameters of the TEMs and the working conditions of the composite system. Furthermore, our analysis shows the effect of the number of thermocouples on the system. These considerations are very useful for the design of thermoelectric composite systems. We reproduce the qualitative behavior of a commercial composite TEM connected electrically in series.

  1. Design, construction, and measurement of a large solar powered thermoacoustic cooler

    Science.gov (United States)

    Chen, Reh-Lin

    2001-07-01

    A device based on harnessing concentrated solar power in combination with using thermoacoustic principles has been built, instrumented, and tested. Its acoustic power is generated by solar radiation and is subsequently used to pump heat from external loads. The direct conversion between thermal and mechanical energy without going through any electronic stage makes the mechanism simple. Construction of the solar collector is also rather unsophisticated. It was converted from a 10-ft satellite dish with aluminized Mylar glued on the surface. The thermoacoustic device was mounted on the dish with its engine's hot side positioned near the focus of the parabolic dish, about 1 meter above the center of the dish. A 2-dimensional solar tracking system was built, using two servo motors to position the dish at pre-calculated coordinates. The solar powered thermoacoustic cooler is intended to be used where solar power is abundant and electricity may not be available or reliable. The cooler provides cooling during solar availability. Cooling can be maintained by the latent heat of ice when solar power is unattainable. The device has achieved cooling although compromised by gas leakage and thermal losses and was not able to provide temperatures low enough to freeze water. Improvements of the device are expected through modifications suggested herein.

  2. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2014-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  3. Optimising the operation of hybrid coolers by means of efficient control equipment; Optimierung der Betriebsweise von Hybridkuehlern durch effiziente Steuerungstechnik

    Energy Technology Data Exchange (ETDEWEB)

    Odrich, T.; Koenig, H. [Jaeggi/Guentner (Schweiz) AG, Trimbach (Switzerland)

    2007-07-01

    Due to its functional principle and design, the hybrid dry cooler holds a high potential for saving water and energy. Purely convective heat discharge during dry operation in the case of a high annual rate of utilisation, evaporative cooling during the wetting cycle at peak load times or high ambient temperatures and infinitely adjustable fan speed in both operating modes permit a very substantial recooling performance at low operating costs and with little space requirement. However, the efficiency of hybrid dry coolers depends to a large degree on how intelligently the cooling functions are controlled and on the control strategy. The present article demonstrates that the control strategy contributes decisively to minimising water and energy consumption and costs. Besides describing the actual functions of a hybrid cooler control system it presents a control strategy for automatic lowering of the setpoint and hence optimisation of the refrigeration process. It discusses the option of operating multiple hybrid coolers by means of a hydraulic network and presents an optimised control concept for this purpose which is based on a master control unit. In conclusion the study shows that hybrid coolers need their own optimised control unit if maximum savings in energy and water are to be achieved.

  4. ANALISIS PERFORMA SISTEM PENDINGIN RAMAH LINGKUNGAN UNTUK KABIN MOBIL CITY CAR MENGGUNAKAN MODUL TERMO ELECTRIC COOLER TERHADAP KONSUMSI BAHAN BAKAR

    Directory of Open Access Journals (Sweden)

    Mirza Yusuf

    2017-12-01

    Full Text Available Ramah lingkungan menjadi isu yang gencar dalam penelitian. Cloro Fluoro Carbon (CFC yang digunakan dalam AC konvensional akan menguap ke udara bebas  berdampak kerusakan lapisan ozon. Ditinjau secara micro dalam penggunaan sitem pendingin dapat diterapkan pada pendingin kabin mobil. System pendingin mobil konfensional menimbulkan 2 kerugian yaitu lebih boros bahan bakar karena couple pulley compressor AC membebani putaran mesin dan penggunaan CFC yang tidak ramah lingkungan.   System pendingin ramah lingkunagan dan mampu menghemat bahan bakar mesin tersebut dapat kita temukan pada modul thermoelectric.  terobosan baru sistem pendingin tersebut menggunakan modul pendingin Thermo Electric Cooler (TEC yang memanfaatkan sisi dingin pada Thermo Electric Cooler (TEC dengan memanfaatkan seaback effect .  Thermo Electric Cooler (TEC ketika dialiri tegangan DC (arus searah pada kedua jalur kabel penghubungnya maka salah satu sisi akan menjadi panas, sementara sisi satunya akan menjadi dingin. Salahsatu cara yang dapat ditempuh untuk memaksimalkan proses pendinginan, maka sisi panas Thermo Electric Cooler (TEC harus diturunkan temperaturenya serendah mungkin mungkin dengan menggunakan alat penukar kalor heat sink serta dibantu kipas(fan. semakin lama proses pendinginan, maka semakin optimal suhu ruangan yang didinginkan. Dari data Hasil pengujian dapat diketahui perangkat pendingin tersebut mampu bekerja dengan rate penurunan temperature memadai. Selanjutnya dapat dapat diaplikasikan sebagai alat pendingin ruangan yang efektif, efisien dan ramah lingkungan.    Kata kunci:  Kabin mobil, Air Conditioner (AC konvensional, Cloro Fluoro Carbon (CFC, Thermo Electric Cooler (TEC, komponen sistem pendingin.

  5. Improving the Efficiency of the Heat Pump Control System of Carbon Dioxide Heat Pump with Several Evaporators and Gas Coolers

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2016-12-01

    Full Text Available The problem of coordination of the values of the refrigerant flow through the evaporators and gas coolers of the heat pump for the simultaneous production of heat and cold is studied. The compensation of the variations of the total flow through the evaporators is implemented using the variation of the capacity of the compressor and a corresponding change in flow through the auxiliary gas cooler of the heat pump. Control system of this gas cooler is constructed using the invariance principle of the output value (outlet temperature of the heated agent with respect to perturbations on the control channel (the refrigerant flow through the gas cooler. Principle of dual-channel compensation of the disturbance and advancing signal on input of control valve of the refrigerant through the gas cooler is ensured. Due to proposed solution, the intensity of the disturbances on the flow of refrigerant is reduced. Due to proposed technical solution power consumed by the heat pump compressor drive under transients is decreased.

  6. Tree Rings: Timekeepers of the Past.

    Science.gov (United States)

    Phipps, R. L.; McGowan, J.

    One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

  7. Improving the Efficiency of the Heat Pump Control System of Carbon Di-oxide Heat Pump with Several Evaporators and Gas Coolers

    OpenAIRE

    Sit, M.L.; Juravliov, A.A.; Sit, B.M.; Timchenko, D.

    2016-01-01

    The problem of coordination of the values of the refrigerant flow through the evaporators and gas coolers of the heat pump for the simultaneous production of heat and cold is studied. The compensation of the variations of the total flow through the evaporators is implemented using the variation of the capacity of the compressor and a corresponding change in flow through the auxiliary gas cooler of the heat pump. Control system of this gas cooler is constructed using the invariance principle o...

  8. Phase measurement for driven spin oscillations in a storage ring

    Science.gov (United States)

    Hempelmann, N.; Hejny, V.; Pretz, J.; Soltner, H.; Augustyniak, W.; Bagdasarian, Z.; Bai, M.; Barion, L.; Berz, M.; Chekmenev, S.; Ciullo, G.; Dymov, S.; Eversmann, D.; Gaisser, M.; Gebel, R.; Grigoryev, K.; Grzonka, D.; Guidoboni, G.; Heberling, D.; Hetzel, J.; Hinder, F.; Kacharava, A.; Kamerdzhiev, V.; Keshelashvili, I.; Koop, I.; Kulikov, A.; Lehrach, A.; Lenisa, P.; Lomidze, N.; Lorentz, B.; Maanen, P.; Macharashvili, G.; Magiera, A.; Mchedlishvili, D.; Mey, S.; Müller, F.; Nass, A.; Nikolaev, N. N.; Nioradze, M.; Pesce, A.; Prasuhn, D.; Rathmann, F.; Rosenthal, M.; Saleev, A.; Schmidt, V.; Semertzidis, Y.; Senichev, Y.; Shmakova, V.; Silenko, A.; Slim, J.; Stahl, A.; Stassen, R.; Stephenson, E.; Stockhorst, H.; Ströher, H.; Tabidze, M.; Tagliente, G.; Talman, R.; Thörngren Engblom, P.; Trinkel, F.; Uzikov, Yu.; Valdau, Yu.; Valetov, E.; Vassiliev, A.; Weidemann, C.; Wrońska, A.; Wüstner, P.; Zuprański, P.; Żurek, M.; JEDI Collaboration

    2018-04-01

    This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in Jülich using a vector polarized, bunched 0.97 GeV /c deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles.

  9. The design of the Spectrometer Ring at the HIAF

    Science.gov (United States)

    Wu, B.; Yang, J. C.; Xia, J. W.; Yan, X. L.; Hu, X. J.; Mao, L. J.; Sheng, L. N.; Wu, J. X.; Yin, D. Y.; Chai, W. P.; Shen, G. D.; Ge, W. W.; Wang, G.; Zhao, H.; Ruan, S.; Ma, X. W.; Wang, M.; Litvinov, S.; Wen, W. Q.; Chen, X. C.; Chen, R. J.; Tang, M. T.; Wu, W.; Luo, C.; Zhao, T. C.; Shi, C. F.; Fu, X.; Liu, J.; Liang, L.

    2018-02-01

    The Spectrometer Ring (SRing) is an essential part of the High Intensity heavy-ion Accelerator Facility project (HIAF) in China. It is designed as a multi-functional experimental storage ring, which will be able to operate in three ion optical operation modes. The SRing will be used as a time-of-flight mass spectrometer for short-lived, especially neutron-rich nuclei. It will also be used to collect and cool Rare Isotope Beams (RIBs) or highly-charged stable ion beams for nuclear and atomic physics experiments. The design magnetic rigidity is in the range 1.5 to 15 Tm. The beam cooling system consists of stochastic cooling and electron cooling devices. With a help of an electron cooler, stored ions will be decelerated to a minimum energy of 30 MeV/u by RF cavities. The extraction system of the SRing will allow cooled ion beams to be extracted to an external target for further ion manipulations or reaction experiments. The general ion optics design and technical requirements of SRing subsystems are presented and discussed in this paper.

  10. Proceedings of the workshop on polarized targets in storage rings

    International Nuclear Information System (INIS)

    Holt, R.J.

    1984-08-01

    Polarization phenomena have played an increasingly important part in the study of nuclei and nucleons in recent years. Polarization studies have been hampered by the relatively few and rather fragile polarized targets which are presently available. The concept of polarized gas targets in storage rings opens a much wider range of possibilities than is available in the external target geometry. This novel method will represent a considerable advance in nuclear physics and will continue to receive much attention in plans for future facilities. An internal, polarized-target station is being planned for the cooler ring at the Indiana University Cyclotron Facility. Internal targets are compatible with recent designs of electron accelerators proposed by the Massachusetts Institute of Technology and the Southeastern Universities Research Association. The key to nuclear-science programs based on internal targets pivots on recent developments in polarized atomic beam methods, which include the more recent laser-driven polarized targets. The workshop drew together a unique group of physicists in the fields of high-energy, nuclear and atomic physics. The meeting was organized in a manner that stimulated discussion among the 58 participants and focused on developments in polarized target technology and the underlying atomic physics. An impressive array of future possibilities for polarized targets as well as current developments in polarized target technology were discussed at the workshop. Abstracts of individual items from the workshop were prepared separately for the data base

  11. Performance of high-resolution position-sensitive detectors developed for storage-ring decay experiments

    International Nuclear Information System (INIS)

    Yamaguchi, T.; Suzaki, F.; Izumikawa, T.; Miyazawa, S.; Morimoto, K.; Suzuki, T.; Tokanai, F.; Furuki, H.; Ichihashi, N.; Ichikawa, C.; Kitagawa, A.; Kuboki, T.; Momota, S.; Nagae, D.; Nagashima, M.; Nakamura, Y.; Nishikiori, R.; Niwa, T.; Ohtsubo, T.; Ozawa, A.

    2013-01-01

    Highlights: • Position-sensitive detectors were developed for storage-ring decay spectroscopy. • Fiber scintillation and silicon strip detectors were tested with heavy ion beams. • A new fiber scintillation detector showed an excellent position resolution. • Position and energy detection by silicon strip detectors enable full identification. -- Abstract: As next generation spectroscopic tools, heavy-ion cooler storage rings will be a unique application of highly charged RI beam experiments. Decay spectroscopy of highly charged rare isotopes provides us important information relevant to the stellar conditions, such as for the s- and r-process nucleosynthesis. In-ring decay products of highly charged RI will be momentum-analyzed and reach a position-sensitive detector set-up located outside of the storage orbit. To realize such in-ring decay experiments, we have developed and tested two types of high-resolution position-sensitive detectors: silicon strips and scintillating fibers. The beam test experiments resulted in excellent position resolutions for both detectors, which will be available for future storage-ring experiments

  12. Extra Low Energy Antiproton ring ELENA : from the conception to the implementation phase

    CERN Document Server

    Bartmann, W; Breuker, H; Butin, F; Carli, C; Eriksson, T; Maury, S; Pasinelli, S; Tranquille, G; Oelert, W

    2014-01-01

    The Extra Low Energy Antiproton ring (ELENA) is a CERN project aiming at constructing a small 30 m circumference synchrotron to further decelerate antiprotons from the Antiproton Decelerator AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. The ELENA design is now well advanced and the project is moving to the implementation phase. Component design and construction are taking place at present for installation foreseen during the second half of 2015 and beginning of 2016 followed by ring commissioning until the end of 2016. New electrostatic transfer lines to the experiments will be installed and commissioned during the first half of 2017 followed by the first physics operation with ELENA. Basic limitations like Intra Beam Scattering limiting the emittances obtained under electron ...

  13. A Collimation Scheme for Ions Changing Charge State in the LEIR Ring

    CERN Document Server

    Pasternak, Jaroslaw; Carli, Christian; Chanel, Michel; Mahner, Edgar

    2005-01-01

    Avalanche-like pressure rise and an associated decrease of the beam life-time, caused by (i) beam loss due to charge exchange interactions with rest gas molecules and (ii) electron capture from the electron beam of the electron cooler and (iii) ion impact induced outgassing, is a potential limitation for heavy ion accelerators. The vacuum system of the LEIR ring as to be upgraded to reach the dynamical vacuum pressure in the low 10-12 Torr range necessary to reach design performance. A collimation system to intercept lost ions by absorber blocks made of low beam-induced outgassing material will be installed. This paper reviews the collimation scheme and simulations of beam loss patterns around the ring.

  14. SOR-ring failure

    International Nuclear Information System (INIS)

    Kitamura, Hideo

    1981-01-01

    It was in the autumn of 1976 that the SOR-ring (synchrotron radiation storage ring) has commenced the regular operation. Since then, the period when the operation was interrupted due to the failures of SOR-ring itself is in total about 8 weeks. Failures and accidents have occurred most in the vacuum system. Those failure experiences are described on the vacuum, electromagnet, radio-frequency acceleration and beam transport systems with their interrupted periods. The eleven failures in the vacuum system have been reported, such as bellows breakage in a heating-evacuating period, leakage from the bellows of straight-through valves (made in U.S.A. and Japan), and leakage from the joint flange of the vacuum system. The longest interruption was 5 weeks due to the failure of a domestically manufactured straight-through valve. The failures of the electromagnet system involve the breakage in a cooling water system, short circuit of a winding in the Q magnet power transformer, blow of a fuse protecting the deflection magnet power source by the current less than the rating, and others. The failures of the RF acceleration system include the breakage of an output electronic tube the breakage of a cavity ceramic, RF voltage fluctuation due to the contact deterioration at a cavity electrode, and the failure of grid bias power source. It is necessary to select the highly reliable components for the vacuum system because the vacuum system failures require longer time for recovery, and very likely to induce secondary and tertiary failures. (Wakatsuki, Y.)

  15. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

    A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal instability; (8) effects of scattering processes; (9) beam production; and (10) high magnetic fields. Much of the discussion is related to the design parameters of ISABELLE, a 400 x 400 GeV proton---proton intersecting storage accelerator to be built at Brookhaven National Laboratory

  16. Ring-constrained Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Karras, Panagiotis; Mamoulis, Nikos

    2008-01-01

    . This new operation has important applications in decision support, e.g., placing recycling stations at fair locations between restaurants and residential complexes. Clearly, RCJ is defined based on a geometric constraint but not on distances between points. Thus, our operation is fundamentally different......We introduce a novel spatial join operator, the ring-constrained join (RCJ). Given two sets P and Q of spatial points, the result of RCJ consists of pairs (p, q) (where p ε P, q ε Q) satisfying an intuitive geometric constraint: the smallest circle enclosing p and q contains no other points in P, Q...

  17. Femtoslicing in Storage Rings

    CERN Document Server

    Khan, Shaukat

    2005-01-01

    The generation of ultrashort synchrotron radiation pulses by laser-induced energy modulation of electrons and their subsequent transverse displacement, now dubbed "femtoslicing," was demonstrated at the Advanced Light Source in Berkeley. More recently, a femtoslicing user facility was commissioned at the BESSY storage ring in Berlin, and another project is in progress at the Swiss Light Source. The paper reviews the principle of femtoslicing, its merits and shortcomings, as well as the variations of its technical implementation. Various diagnostics techniques to detect successful laser-electron interaction are discussed and experimental results are presented.

  18. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana

    2013-10-15

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  19. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana; Vasilakopoulos, Thodoris C.; Jeong, Youncheol; Lee, Hyojoon; Rogers, Simon A.; Sakellariou, Georgios; Allgaier, Jü rgen B.; Takano, Atsushi; Brá s, Ana Rita E; Chang, Taihyun; Gooß en, Sebastian; Pyckhout-Hintzen, Wim; Wischnewski, Andreas; Hadjichristidis, Nikolaos; Richter, Dieter R.; Rubinstein, Michael H.; Vlassopoulos, Dimitris

    2013-01-01

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  20. Alpha - Skew Pi - Armendariz Rings

    Directory of Open Access Journals (Sweden)

    Areej M Abduldaim

    2018-03-01

    Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

  1. Micromachined Joule-Thomson coolers for cooling low-temperature detectors and electronics

    Science.gov (United States)

    ter Brake, Marcel; Lerou, P. P. P. M.; Burger, J. F.; Holland, H. J.; Derking, J. H.; Rogalla, H.

    2017-11-01

    The performance of electronic devices can often be improved by lowering the operating temperature resulting in lower noise and larger speed. Also, new phenomena can be applied at low temperatures, as for instance superconductivity. In order to fully exploit lowtemperature electronic devices, the cryogenic system (cooler plus interface) should be `invisible' to the user. It should be small, low-cost, low-interference, and above all very reliable (long-life). The realization of cryogenic systems fulfilling these requirements is the topic of research of the Cooling and Instrumentation group at the University of Twente. A MEMS-based cold stage was designed and prototypes were realized and tested. The cooler operates on basis of the Joule-Thomson effect. Here, a high-pressure gas expands adiabatically over a flow restriction and thus cools and liquefies. Heat from the environment (e.g., an optical detector) can be absorbed in the evaporation of the liquid. The evaporated working fluid returns to the low-pressure side of the system via a counter-flow heat exchanger. In passing this heat exchanger, it takes up heat from the incoming high-pressure gas that thus is precooled on its way to the restriction. The cold stage consists of a stack of three glass wafers. In the top wafer, a high-pressure channel is etched that ends in a flow restriction with a height of typically 300 nm. An evaporator volume crosses the center wafer into the bottom wafer. This bottom wafer contains the lowpressure channel thus forming a counter-flow heat exchanger. A design aiming at a net cooling power of 10 mW at 96 K and operating with nitrogen as the working fluid was optimized based on the minimization of entropy production. The optimum cold finger measures 28 mm x 2.2 mm x 0.8 mm operating with a nitrogen flow of 1 mg/s at a high pressure of 80 bar and a low pressure of 6 bar. The design and fabrication of the coolers will be discussed along with experimental results.

  2. Novel concept for driving the linear compressor of a micro-miniature split Stirling cryogenic cooler

    Science.gov (United States)

    Maron, V.; Veprik, A.; Finkelstein, L.; Vilenchik, H.; Ziv, I.; Pundak, N.

    2009-05-01

    New methods of carrying out homeland security and antiterrorist operations call for the development of a new generation of mechanically cooled, portable, battery powered infrared imagers, relying on micro-miniature Stirling cryogenic coolers of rotary or linear types. Since split Stirling linearly driven micro-miniature cryogenic coolers have inherently longer life spans, low vibration export and better aural stealth as compared to their rotary driven rivals, they are more suitable for the above applications. The performance of such cryogenic coolers depends strongly on the efficacy of their electronic drivers. In a traditional approach, the PWM power electronics produce the fixed frequency tonal driving voltage/current, the magnitude of which is modulated via a PID control law so as to maintain the desired focal plane array temperature. The disadvantage of such drivers is that they draw high ripple current from the system's power bus. This results in the need for an oversized DC power supply (battery packs) and power electronic components, low efficiency due to excessive conductive losses and high residual electromagnetic interference which in turn degrades the performance of other systems connected to the same power bus. Without either an active line filter or large and heavy passive filtering, other electronics can not be powered from the same power bus, unless they incorporate heavy filtering at their inputs. The authors present the results of a feasibility study towards developing a novel "pumping" driver consuming essentially constant instant battery power/current without making use of an active or passive filter. In the tested setup, the driver relies on a bidirectional controllable bridge, invertible with the driving frequency, and a fast regulated DC/DC converter which maintains a constant level of current consumed from the DC power supply and thus operates in input current control mode. From the experimental results, the steady-state power consumed by the

  3. Development of In-Service Inspection system for heat transfer tubes in the primary pressurized water cooler in the HTTR

    Energy Technology Data Exchange (ETDEWEB)

    Shinozaki, Masayuki; Furusawa, Takayuki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Wada, Shigeyuki

    1999-08-01

    The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)

  4. NRL ion ring program

    International Nuclear Information System (INIS)

    Kapetanakos, C.A.; Golden, J.; Drobot, A.; Mahaffey, R.A.; Marsh, S.J.; Pasour, J.A.

    1977-01-01

    An experiment is under way to form a storng proton ring using the 200 ka, 1.2 MeV, 50 nsec hollow proton beam recently generated at NRL. The 5 m long magnetic field configuration consists of a magnetic cusp, a compressing magnetic field, a gate field and a magnetic mirror. The midplane value of the magnetic mirror is such that the major radius of the ring will be about 10 cm. The degree of field reversal that will be achieved with 5 x 10 16 protons per pulse from the existing beam depends upon the field reversal is possible with the 600 kA proton beam that would be generated from the low inductance coaxial triode coupled to the upgraded Gamble II generator. The propagation and trapping of an intense proton beam in the experimental magnetic field configuration is investigated numerically. The results show that the self magnetic has a very pronounced effect on the dynamics of the gyrating protons

  5. Flexible ring seal

    International Nuclear Information System (INIS)

    Abbes, Claude; Gournier, Andre; Rouaud, Christian; Villepoix, Raymond de.

    1976-01-01

    The invention concerns a flexible metal ring seal, able to ensure a perfect seal between two bearings due to the crushing and elastic deformation properties akin to similar properties in elastomers. Various designs of seal of this kind are already known, particularly a seal made of a core formed by a helical wire spring with close-wound turns and with high axial compression ratio, closed on itself and having the shape of an annulus. This wire ring is surrounded by at least one envelope having at rest the shape of a toroidal surface of which the generating circle does not close on itself. In a particular design mode, the seal in question can include, around the internal spring, two envelopes of which one in contact with the spring is composed of a low ductility elastic metal, such as mild steel or stainless steel and the other is, on the contrary, made of a malleable metal, such as copper or nickel. The first envelope evenly distributes the partial crushing of the spring, when the seal is tightened, on the second envelope which closely fits the two surfaces between which the seal operates. The stress-crushing curve characteristic of the seal comprises two separate parts, the first with a relatively sharp slope corresponds to the start of the seal compression phase, enabling at least some of these curves to reach the requisite seal threshold very quickly, then, beyond this, a second part, practically flat, where the stress is appreciably constant for a wide operating bracket [fr

  6. Magnetization of two coupled rings

    International Nuclear Information System (INIS)

    Avishai, Y; Luck, J M

    2009-01-01

    We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of two-fold and three-fold degeneracies, the key role of length and flux commensurability, and in the case of commensurate ring lengths the occurrence of idle levels which do not carry any current. Spin-orbit interactions, induced by the electric fields of charged wires threading the rings, give rise to a peculiar version of the Aharonov-Casher effect where, unlike for a single ring, spin is not conserved. Remarkably enough, this can only be realized when the Aharonov-Bohm fluxes in both rings are neither integer nor half-integer multiples of the flux quantum

  7. Dry Air Cooler Modeling for Supercritical Carbon Dioxide Brayton Cycle Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, J. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Lv, Q. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-07-28

    Modeling for commercially available and cost effective dry air coolers such as those manufactured by Harsco Industries has been implemented in the Argonne National Laboratory Plant Dynamics Code for system level dynamic analysis of supercritical carbon dioxide (sCO2) Brayton cycles. The modeling can now be utilized to optimize and simulate sCO2 Brayton cycles with dry air cooling whereby heat is rejected directly to the atmospheric heat sink without the need for cooling towers that require makeup water for evaporative losses. It has sometimes been stated that a benefit of the sCO2 Brayton cycle is that it enables dry air cooling implying that the Rankine steam cycle does not. A preliminary and simple examination of a Rankine superheated steam cycle and an air-cooled condenser indicates that dry air cooling can be utilized with both cycles provided that the cycle conditions are selected appropriately

  8. Studies and conception of a radiofrequency cooler for high intensity beams

    International Nuclear Information System (INIS)

    Duval, Florian

    2009-01-01

    The topic of this thesis is the study and the conception of a RFQ Cooler with buffer gas for high intensity radioactive beams. This project is in the frame of the next extension of GANIL, Spiral2, and the future low-energy facility DESIR ('Decay, Excitation and Storage of Radioactive ions'). The goal is to reduce the beams emittance of Spiral2 beams to allow their purification (ideally at isobaric level) with a high resolution separator. This cooler consists on a quadrupolar structure on which ions are confined by RF potential in opposite phase at an energy of 100 eV. A light buffer-gas, typically helium, is injected in the quadrupole and, after each collision, the ion lose a part of its energy and is finally cooled. The main problem on our project concerns the space charge. The existing devices are able to cool currents of few 10 nA whereas we have to treat beam intensities around 1 μA which induce an increase of the Coulomb repulsion between ions. That needs to produce strong RF fields which induce high RF potentials (≅ 10 kV_p_p) and a low inner radius (r_0 ≅ 3 a 5 mm). We have worked on a first prototype, SHIRaC-Phase1 ('Spiral2 High Intensity Radiofrequency Cooler'), with a 3 mm-inner radius, built at CSNSM-Orsay and moved at LPC-Caen at the end of 2007. The main R and D effort concerns the electronic part. A first RF system, based on a LC resonant circuit, has been developed and has provided up to 2500 V_p_p between 4.5 and 6.3 MHz. In these conditions, we have checked that we didn't have strong limitations from electrical breakdown between our electrodes. With this device, we have reduced the beam emittance to a value around 2 π.mm.mrad at 60 keV and the longitudinal energy spread to 146 meV. The maximum transmission of Sodium "2"3Na"+ and Rubidium "8"7Rb"+ is 25% with an ionization source for which the beam quality is better than Spiral2. For this reason, we have conceived a new cooler with an acceptance of 80 π.mm.mrad at 60 keV. This second

  9. Upgrade of the radio frequency quadrupole cooler and buncher for the HIE-ISOLDE project

    CERN Document Server

    Babcock, Carla

    2013-01-01

    The upgrade to the ISOLDE facility, HIE-ISOLDE, will include an upgrade to the RFQCB (radio frequency quadrupole cooler and buncher), the focus of which will be fixing the problems of alignment with the current machine, improving the integrity of the vacuum system, stabilizing the internal gas pressure, and the changes associated with a new position. The beam passage inside the RFQCB has been simulated with an independent code to highlight the importance of the internal gas pressure, to motivate design changes in the new RFQCB and to explain ways to improve the performance of the current machine. The suspected misalignment of ISCOOL has been quantified, and, using a simulation of ions passing through the external injection electrodes, the effect of the misalignment on machine acceptance has been detailed. Plans for the future RFQCB test stand and HIE-ISOLDE installation have been outlined. (C) 2013 Elsevier B.V. All rights reserved.

  10. Effect of operating conditions on performance of silica gel-water air-fluidised desiccant cooler

    Directory of Open Access Journals (Sweden)

    Rogala Zbigniew

    2017-01-01

    Full Text Available Fluidised desiccant cooling is reported in the literature as an efficient way to provide cooling for air-conditioning purposes. The performance of this technology can be described by electric and thermal Coefficients of Performance (COP and Specific Cooling Power (SCP. In this paper comprehensive theoretical study was carried out in order to assess the effect of operating conditions such as: superficial air velocity, desiccant particle diameter, bed switching time and desiccant filling height on the performance of fluidised desiccant cooler (FDC. It was concluded that FDC should be filled with as small as possible desiccant particles featuring diameters and should not be operated with shorter switching times than optimum. Moreover in order to efficiently run such systems superficial air velocities during adsorption and desorption should be similar. At last substantial effect of desiccant filling height on performance of FDC was presented.

  11. Optimal Integration of Cascade Thermoelectric Cooler into Electronic Housing: Experimental Approach

    Science.gov (United States)

    Semeniuk, V.; Protsenko, D.

    2018-06-01

    The problem of the optimal integration of thermoelectrically cooled optoelectronic components into an electronic housing is studied with the emphasis on practical implementation. The lines of 2-stage and 3-stage thermoelectric coolers (TECs) compatible with TO8 housing have been developed, and their parameters are measured in a wide range of heat sink temperatures. The TECs are optimized to receive a temperature difference of 100-110 K under a heat load from 70 mW to 100 mW with minimal power consumption. To fit into a standard housing interior, all the TECs have the same overall dimensions, regardless of the number of stages. Details of the TEC configurations and their performance characteristics are presented and discussed.

  12. Ice detection in heat pumps and coolers. [By thermal resistance and capacitance detection

    Energy Technology Data Exchange (ETDEWEB)

    Buick, T R; McMullan, J T; Morgan, R; Murray, R B

    1978-01-01

    Some methods are discussed for detecting the formation of ice on the evaporators of air-source heat pumps and air coolers by electronic means. The sensing of thermal resistance caused by ice build-up can be done by measuring temperature differences between the evaporator and the air, and analyses are presented of the effect of using both linear and non-linear temperature sensors for this purpose. The direct detection of the presence of ice can be done by measuring the capacitance of a suitably-placed pair of plates, and the performance of such a system is analyzed. Preliminary reports are presented of the use of both of these methods of ice detection in the defrosting of an experimental heat pump.

  13. Numerical Analysis and Design of Thermal Management System for Lithium Ion Battery Pack Using Thermoelectric Coolers

    Directory of Open Access Journals (Sweden)

    Yong Liu

    2014-08-01

    Full Text Available A new design of thermal management system for lithium ion battery pack using thermoelectric coolers (TECs is proposed. Firstly, the 3D thermal model of a high power lithium ion battery and the TEC is elaborated. Then the model is calibrated with experiment results. Finally, the calibrated model is applied to investigate the performance of a thermal management system for a lithium ion battery pack. The results show that battery thermal management system (BTMS with TEC can cool the battery in very high ambient temperature. It can also keep a more uniform temperature distribution in the battery pack than common BTMS, which will extend the life of the battery pack and may save the expensive battery equalization system.

  14. Design aspects of an electrostatic electron cooler for low-energy RHIC operation

    International Nuclear Information System (INIS)

    Fedotov, A.; Ben-Zvi, I.; Brodowski, J.; Chang, X.Y.; Gassner, D.; Hoff, L.; Kayran, D.; Kewisch, J.; Oerter, B.; Pendzick, A.; Tepikian, S.; Thieberger, P.; Prost, L.; Shemyakin, A.

    2011-01-01

    Electron cooling was proposed to increase the luminosity of the Relativistic Heavy Ion Collider (RHIC) operation for heavy ion beam energies below 10 GeV/nucleon. The electron cooling system needed should be able to deliver an electron beam of adequate quality in a wide range of electron beam energies (0.9-5 MeV). An option of using an electrostatic accelerator to produce electrons for cooling heavy ions in RHIC was evaluated in detail. In this paper, we describe the requirements and options which were considered in the design of such a cooler for RHIC, as well as the associated challenges. The expected luminosity improvement and limitations with such an electron cooling system are also discussed.

  15. Split ring containment attachment device

    International Nuclear Information System (INIS)

    Sammel, A.G.

    1996-01-01

    A containment attachment device is described for operatively connecting a glovebag to plastic sheeting covering hazardous material. The device includes an inner split ring member connected on one end to a middle ring member wherein the free end of the split ring member is inserted through a slit in the plastic sheeting to captively engage a generally circular portion of the plastic sheeting. A collar potion having an outer ring portion is provided with fastening means for securing the device together wherein the glovebag is operatively connected to the collar portion. 5 figs

  16. Radar imaging of Saturn's rings

    Science.gov (United States)

    Nicholson, Philip D.; French, Richard G.; Campbell, Donald B.; Margot, Jean-Luc; Nolan, Michael C.; Black, Gregory J.; Salo, Heikki J.

    2005-09-01

    We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ˜77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-section of the C ring and 9% on that of the Cassini Division. These results are consistent with those obtained by Ostro et al. [1982, Icarus 49, 367-381] from radar observations at |B|=21.4°, but provide higher resolution maps of the rings' reflectivity profile. The average cross-section of the A and B rings, normalized by their projected unblocked area, is found to have decreased from 1.25±0.31 to 0.74±0.19 as the rings have opened up, while the circular polarization ratio has increased from 0.64±0.06 to 0.77±0.06. The steep decrease in cross-section is at variance with previous radar measurements [Ostro et al., 1980, Icarus 41, 381-388], and neither this nor the polarization variations are easily understood within the framework of either classical, many-particle-thick or monolayer ring models. One possible explanation involves vertical size segregation in the rings, whereby observations at larger elevation angles which see deeper into the rings preferentially see the larger particles concentrated near the rings' mid-plane. These larger particles may be less reflective and/or rougher and thus more depolarizing than the smaller ones. Images from all four years show a strong m=2 azimuthal asymmetry in the reflectivity of the A ring, with an amplitude of ±20% and minima at longitudes of 67±4° and 247±4° from the sub-Earth point. We attribute the asymmetry to the presence of gravitational wakes in the A ring as invoked by Colombo et al. [1976, Nature 264, 344-345] to explain the similar asymmetry long seen at optical wavelengths. A simple radiative transfer model suggests that the enhancement of the azimuthal

  17. Magnetic ring for stripping enhancement

    International Nuclear Information System (INIS)

    Selph, F.

    1992-10-01

    A ring designed to recycle ions through a stripping medium offers the possibility for increasing output of the desired charge state by up to 4x. This could be a very important component of a Radioactive Nuclear Beam Facility. In order for such a ring to work effectively it must satisfy certain design conditions. These include achromaticity at the stripper, a dispersed region for an extraction magnet, and a number of first and higher order optics constraints which are necessary to insure that the beam emittance is not degraded unduly by the ring. An example is given of a candidate design of a stripping ring

  18. Saturn's Rings Edge-on

    Science.gov (United States)

    1995-01-01

    In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

  19. Acceleration of magnetized plasma rings

    International Nuclear Information System (INIS)

    Hartman, D.; Eddleman, J.; Hammer, J.H.

    1982-01-01

    One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  20. Ground Movement in SSRL Ring

    International Nuclear Information System (INIS)

    Sunikumar, Nikita

    2011-01-01

    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  1. ring og refleksion

    DEFF Research Database (Denmark)

    Wahlgren, B.; Rattleff, Pernille; Høyrup, S.

    State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....

  2. Integrated solar water-heater and solar water cooler performance during winter time

    International Nuclear Information System (INIS)

    Shaikh, N.U.; Siddiqui, M.A

    2012-01-01

    Solar powered water heater and water cooler is an important contribution for the reduction of fossil fuel consumptions and harmful emissions to the environment. This study aims to harness the available solar potential of Pakistan and provide an option fulfilling the domestic hot and cold water demands during winter and summer seasons respectively. The system was designed for the tap-water temperature of 65 degree C (149 degree F) and the chilled drinking-water temperature of 14 degree C (57 degree F) that are the recommended temperatures by World Health Organization (WHO). The solar water heater serves one of the facilities of the Department of Mechanical Engineering at NED University of Engineering and Technology whereas, the solar water cooler will provide drinking water to approximately 50 people including both faculty and students. A pair of single glazed flat plate solar collector was installed to convert solar radiations to heat. Hot water storage and supply system was carefully designed and fabricated to obtain the designed tap-water temperature. Vapour-absorption refrigeration system was designed to chill drinking water. Intensity of solar radiations falling on the solar collector, water temperatures at the inlet and outlet of the solar collectors and the tap water temperature were measured and analyzed at different hours of the day and at different days of the month. The results show that the installed solar collector system has potential to feed hot water of temperatures ranging from 65 degree C (149 degree F) to 70 Degree C (158 degree F), that is the required hot water temperature to operate a vapour absorption chilled water production system. (author)

  3. Diagnosis of Catalyst Cooler and Riser in RFCC using Sealed gamma-ray Source

    International Nuclear Information System (INIS)

    Kim, Jin Seop; Kim, Jong Bum; Jung, Sung Hee; Kim, Jae Ho

    2005-12-01

    With a quantitative growth of the petroleum industry, a lot of budget are spent for the maintenance and repairs of facilities related to the process annually. Among them, the RFCC(residual fluid catalytic cracking) is a highly value-added unit which converts gas oil and heavier streams to lighter, more valuable products such as propylene, gasoline by an injection of atmospheric residue into the fluided catalyst. In this study, field experiments were performed to analyze the reasons of an abnormal operation in the catalyst cooler and the catalyst riser belonged to the RFCC unit respectively and to estimate the amount of seriousness using sealed gamma-ray source( 60 Co). The catalyst cooler functions cooling for the regeneration of a catalyst, which will be used to a new media in the RFCC unit. The catalyst riser, while, plays an important part in transporting to next cyclotron steps by mixing of an oil, steam and a catalyst mechanically. The purposes of this study is what was the condition of catalyst flow pattern and whether the coke was produced in an inside process or not. Gamma radiation counts were measured by the detector(NaI) positioned outside the pipe-wall diametrically opposite to the gamma source with a regular space. From the results, the section different from the distribution pattern of nearby catalyst in a facility was found. And this became the definitive information to a process operator. Diagnosis technique using gamma radiation source is proved to be the effective and reliable method in providing information on the media distribution in a facility

  4. Cooler temperatures destabilize RNA interference and increase susceptibility of disease vector mosquitoes to viral infection.

    Directory of Open Access Journals (Sweden)

    Zach N Adelman

    Full Text Available The impact of global climate change on the transmission dynamics of infectious diseases is the subject of extensive debate. The transmission of mosquito-borne viral diseases is particularly complex, with climatic variables directly affecting many parameters associated with the prevalence of disease vectors. While evidence shows that warmer temperatures often decrease the extrinsic incubation period of an arthropod-borne virus (arbovirus, exposure to cooler temperatures often predisposes disease vector mosquitoes to higher infection rates. RNA interference (RNAi pathways are essential to antiviral immunity in the mosquito; however, few experiments have explored the effects of temperature on the RNAi machinery.We utilized transgenic "sensor" strains of Aedes aegypti to examine the role of temperature on RNA silencing. These "sensor" strains express EGFP only when RNAi is inhibited; for example, after knockdown of the effector proteins Dicer-2 (DCR-2 or Argonaute-2 (AGO-2. We observed an increase in EGFP expression in transgenic sensor mosquitoes reared at 18°C as compared with 28°C. Changes in expression were dependent on the presence of an inverted repeat with homology to a portion of the EGFP sequence, as transgenic strains lacking this sequence, the double stranded RNA (dsRNA trigger for RNAi, showed no change in EGFP expression when reared at 18°C. Sequencing small RNAs in sensor mosquitoes reared at low temperature revealed normal processing of dsRNA substrates, suggesting the observed deficiency in RNAi occurs downstream of DCR-2. Rearing at cooler temperatures also predisposed mosquitoes to higher levels of infection with both chikungunya and yellow fever viruses.This data suggest that microclimates, such as those present in mosquito breeding sites, as well as more general climactic variables may influence the dynamics of mosquito-borne viral diseases by affecting the antiviral immunity of disease vectors.

  5. Nanoscale coatings for erosion and corrosion protection of copper microchannel coolers for high powered laser diodes

    Science.gov (United States)

    Flannery, Matthew; Fan, Angie; Desai, Tapan G.

    2014-03-01

    High powered laser diodes are used in a wide variety of applications ranging from telecommunications to industrial applications. Copper microchannel coolers (MCCs) utilizing high velocity, de-ionized water coolant are used to maintain diode temperatures in the recommended range to produce stable optical power output and control output wavelength. However, aggressive erosion and corrosion attack from the coolant limits the lifetime of the cooler to only 6 months of operation. Currently, gold plating is the industry standard for corrosion and erosion protection in MCCs. However, this technique cannot perform a pin-hole free coating and furthermore cannot uniformly cover the complex geometries of current MCCs involving small diameter primary and secondary channels. Advanced Cooling Technologies, Inc., presents a corrosion and erosion resistant coating (ANCERTM) applied by a vapor phase deposition process for enhanced protection of MCCs. To optimize the coating formation and thickness, coated copper samples were tested in 0.125% NaCl solution and high purity de-ionized (DIW) flow loop. The effects of DIW flow rates and qualities on erosion and corrosion of the ANCERTM coated samples were evaluated in long-term erosion and corrosion testing. The robustness of the coating was also evaluated in thermal cycles between 30°C - 75°C. After 1000 hours flow testing and 30 thermal cycles, the ANCERTM coated copper MCCs showed a corrosion rate 100 times lower than the gold plated ones and furthermore were barely affected by flow rates or temperatures thus demonstrating superior corrosion and erosion protection and long term reliability.

  6. Rotating ring-ring electrode theory and experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  7. The Rotating Ring-Ring Electrode. Theory and Experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  8. Damping rings for CLIC

    CERN Document Server

    Jowett, John M; Zimmermann, Frank; Owen, H

    2001-01-01

    The Compact Linear Colider (CLIC) is designed to operate at 3 TeV centre-of-mass energy with a total luminosity of 10^35 cm^-2 s^-1. The overall system design leads to extremely demanding requirements on the bunch trains injected into the main libac at frequency of 100 Hz. In particular, the emittances of the intense bunches have to be about an order of magnitude smaller than presently achieved. We describe our approach to finding a damping ring design capable of meeting these requirements. Besides lattice design, emittance and damping rate considerations, a number of scattering and instability effects have to be incorporated into the optimisation of parameters. Among these, intra-bem scattering and the electron cloud effect are two of the most significant.

  9. Does the sun ring

    International Nuclear Information System (INIS)

    Isaak, G.R.

    1978-01-01

    The work of various groups, which have been investigating the possibility of measuring the periodicities of solar oscillations in an attempt to test theoretical models of the sun, is reported. In particular the observation of small velocity oscillations of the surface layers of the sun that permits the measurement of the sound waves (or phonons) in the solar atmosphere, is discussed. Oscillations with periods of 2.65 h, 58 and 40 min and amplitudes of 2.7, 0.8 and 0.7 ms -1 respectively are reported. Support for a periodicity at about 2.65 h from a number of other groups using other measuring techniques are considered. It is felt that the most probable interpretation of the observed solar oscillations is that the sun is a resonator which is ringing. (UK)

  10. Interference characterisation of a commercial Joule-Thomson cooler to be used in a SQUID-based heart monitor

    NARCIS (Netherlands)

    Bangma, M.R.; Bangma, M.R.; Rijpma, A.P.; de Vries, E.; Reincke, H.A.; Holland, Herman J.; ter Brake, Hermanus J.M.; Rogalla, Horst

    2001-01-01

    At the University of Twente, a foetal heart monitor based on a high-TC SQUID magnetometer system is under development. The purpose of this system is to measure a foetal heart signal in a clinical environment. For cooling a first demonstrator version, a closed-cycle Joule–Thomson cooler from APD

  11. Interference characterisation of a commercial Joule-Thomson cooler to be used in a SQUID-based foetal heart monitor

    NARCIS (Netherlands)

    Bangma, M.R.; Rijpma, A.P.; Vries, de E.; Reincke, H.A.; Holland, H.J.; Brake, ter H.J.M.; Rogalla, H.

    2001-01-01

    At the University of Twente, a fetal heart monitor based on a high-TC SQUID magnetometer system is under development. The purpose of this system is to measure a fetal heart signal in a clin. environment. For cooling a first demonstrator version, a closed-cycle Joule-Thomson cooler from APD

  12. Feasibility and impact of placing water coolers on sales of sugar-sweetened beverages in Dutch secondary school canteens

    NARCIS (Netherlands)

    Visscher, Tommy L S; van Hal, Wendy C W; Blokdijk, Lobke; Seidell, Jaap C; Renders, Carry M; Bemelmans, Wanda J E

    2010-01-01

    AIMS: The aim of this pilot study was to investigate the feasibility and effectiveness of placing water coolers on sugar-sweetened beverage sales at secondary schools (age 12-18 years) in the city of Zwolle, the Netherlands. METHODS: Six schools, hosting 5,866 pupils, were divided in three

  13. Qualification campaign of the 50 mK hybrid sorption-ADR cooler for SPICA/SAFARI

    International Nuclear Information System (INIS)

    Duval, J-M; Duband, L; Attard, A

    2015-01-01

    SAFARI (SpicA FAR-infrared Instrument) is an infrared instrument planned to be part of the SPICA (SPace Infrared telescope for Cosmology and Astrophysics) Satellite. It will offer high spectral resolution in the 30 - 210 μm frequency range. SAFARI will benefit from the cold telescope of SPICA and to obtain the required detectors sensitivity, a temperature of 50 mK is required. This temperature is reached thanks to the use of a hybrid sorption - ADR (Adiabatic Demagnetization Refrigerator) cooler presented here. This cooler provides respectively 14 μW and 0.4 μW of cooling power at 300 mK and 50 mK. The cooler is planned to advantageously use two thermal interfaces of the instrument at 1.8 and 4.9 K. One of the challenges discussed in this paper is the low power available at each intercept. A dedicated laboratory electronic is being designed based on previous development with a particular focus on the 50 mK readout. Temperature regulation at 50 mK is also discussed. This cooler has been designed following flight constraints and will reach a high TRL, including mechanical and environmental tests at the end of the on-going qualification campaign. (paper)

  14. Qualification campaign of the 50 mK hybrid sorption-ADR cooler for SPICA/SAFARI

    Science.gov (United States)

    Duval, J.-M.; Duband, L.; Attard, A.

    2015-12-01

    SAFARI (SpicA FAR-infrared Instrument) is an infrared instrument planned to be part of the SPICA (SPace Infrared telescope for Cosmology and Astrophysics) Satellite. It will offer high spectral resolution in the 30 - 210 μm frequency range. SAFARI will benefit from the cold telescope of SPICA and to obtain the required detectors sensitivity, a temperature of 50 mK is required. This temperature is reached thanks to the use of a hybrid sorption - ADR (Adiabatic Demagnetization Refrigerator) cooler presented here. This cooler provides respectively 14 μW and 0.4 μW of cooling power at 300 mK and 50 mK. The cooler is planned to advantageously use two thermal interfaces of the instrument at 1.8 and 4.9 K. One of the challenges discussed in this paper is the low power available at each intercept. A dedicated laboratory electronic is being designed based on previous development with a particular focus on the 50 mK readout. Temperature regulation at 50 mK is also discussed. This cooler has been designed following flight constraints and will reach a high TRL, including mechanical and environmental tests at the end of the on-going qualification campaign.

  15. 75 FR 186 - Energy Conservation Program: Test Procedures for Walk-In Coolers and Walk-In Freezers

    Science.gov (United States)

    2010-01-04

    .... Measuring the U Value of glass 10. Floor R Value 11. Electrical Duty Cycle 12. Normalization Factor 13... coolers and freezers. The walk-in envelope includes, but may not be limited to, walls, floor, ceiling... performance (this process is also known as ``aging''). This diffusion process causes foam to lose insulating...

  16. Optimal analysis of gas cooler and intercooler for two-stage CO2 trans-critical refrigeration system

    International Nuclear Information System (INIS)

    Li, Wenhua

    2013-01-01

    Highlights: • Simplified model for tube-fin gas cooler for CO 2 refrigeration system was presented and validated. • Several parameters were investigated using 1st law and 2nd law in component and system level. • Practical guidelines of optimum for tube-fin gas cooler and intercooler were proposed. - Abstract: Energy-based 1st law and exergy-based 2nd law are both employed in the paper to assess the optimal design of gas cooler and intercooler for two-stage CO 2 refrigeration system. A simplified mathematical model of the air-cooled coil is presented and validated against experimental data with good accuracy. The optimum circuit length under the influence of frontal air velocity and deep rows is investigated first. Thereafter, designed coil with optimum circuit length is further evaluated within the two-stage refrigeration system. It is found out the optimum point using 1st law does not coincide with the point using 2nd law in isolated component and the simulation results from isolated component by 2nd law are closer to system analysis. Results show optimum circuit length is much bigger for gas cooler than intercooler and the influence on the length from variation of frontal air velocity and deep rows may be neglected. There does exist optimum frontal air velocity which will decrease with more number of deep rows

  17. 75 FR 55067 - Energy Conservation Program: Test Procedures for Walk-In Coolers and Walk-In Freezers

    Science.gov (United States)

    2010-09-09

    ... submitted using any of the following methods: 1. Federal eRulemaking Portal: http://www.regulations.gov... Proposal III. Discussion A. Overall Issues 1. Definition of Walk-In Cooler or Freezer: Temperature Limit 2.... Description and Estimated Number of Small Entities Regulated 4. Description and Estimate of Compliance...

  18. Effects of PM fouling on the heat exchange effectiveness of wave fin type EGR cooler for diesel engine use

    Science.gov (United States)

    Jang, Sang-Hoon; Hwang, Se-Joon; Park, Sang-Ki; Choi, Kap-Seung; Kim, Hyung-Man

    2012-06-01

    Developing an effective method of reducing nitrogen oxide emissions is an important goal in diesel engine research. The use of cooled exhaust gas recirculation has been considered one of the most effective techniques of reducing nitrogen oxide. However, since the combustion characteristics in a diesel engine involves high temperature and load, the amount of particulate matter emission tends to increase, and there is a trade-off between the amount of nitrogen oxide and particulate matter emissions. In the present study, engine dynamometer experiments are performed to investigate the effects of particulate matter fouling on the heat exchange characteristics of wave fin type exhaust gas recirculation coolers that have four cases of two wave pitch and three fin pitch lengths. To optimize the fin and wave pitches of the EGR cooler, the exhaust gas temperature, pressure drop and heat exchange effectiveness are compared. The experimental results show that the exhaust gas recirculation cooler with a fin pitch of 3.6 mm and a wave pitch of 8.8 mm exhibits better heat exchange characteristics and smaller particulate matter fouling effect than the other coolers.

  19. Effects of PM fouling on the heat exchange effectiveness of wave fin type EGR cooler for diesel engine use

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Sang-Hoon; Hwang, Se-Joon; Choi, Kap-Seung; Kim, Hyung-Man [INJE University, Department of Mechanical Engineering, High Safety Vehicle Core Technology Research Center, Gimhae-si, Gyeongnam-do (Korea, Republic of); Park, Sang-Ki [Hanyang University, Graduate School of Mechanical Engineering, Ansan, Gyeonggido (Korea, Republic of)

    2012-06-15

    Developing an effective method of reducing nitrogen oxide emissions is an important goal in diesel engine research. The use of cooled exhaust gas recirculation has been considered one of the most effective techniques of reducing nitrogen oxide. However, since the combustion characteristics in a diesel engine involves high temperature and load, the amount of particulate matter emission tends to increase, and there is a trade-off between the amount of nitrogen oxide and particulate matter emissions. In the present study, engine dynamometer experiments are performed to investigate the effects of particulate matter fouling on the heat exchange characteristics of wave fin type exhaust gas recirculation coolers that have four cases of two wave pitch and three fin pitch lengths. To optimize the fin and wave pitches of the EGR cooler, the exhaust gas temperature, pressure drop and heat exchange effectiveness are compared. The experimental results show that the exhaust gas recirculation cooler with a fin pitch of 3.6 mm and a wave pitch of 8.8 mm exhibits better heat exchange characteristics and smaller particulate matter fouling effect than the other coolers. (orig.)

  20. 40 CFR 63.1348 - Standards for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

    Science.gov (United States)

    2010-07-01

    ... than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw and finish mills. 63.1348 Section 63.1348 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw and...

  1. How Jupiter's Ring Was Discovered.

    Science.gov (United States)

    Elliot, James; Kerr, Richard

    1985-01-01

    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  2. Pyrimidine-pyridine ring interconversion

    NARCIS (Netherlands)

    Plas, van der H.C.

    2003-01-01

    This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the

  3. Binomial Rings: Axiomatisation, Transfer and Classification

    OpenAIRE

    Xantcha, Qimh Richey

    2011-01-01

    Hall's binomial rings, rings with binomial coefficients, are given an axiomatisation and proved identical to the numerical rings studied by Ekedahl. The Binomial Transfer Principle is established, enabling combinatorial proofs of algebraical identities. The finitely generated binomial rings are completely classified. An application to modules over binomial rings is given.

  4. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer

    2005-06-01

    Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

  5. Evaluation of ring impedance of the Photon Factory storage ring

    International Nuclear Information System (INIS)

    Kiuchi, T.; Izawa, M.; Tokumoto, S.; Hori, Y.; Sakanaka, S.; Kobayashi, M.; Kobayakawa, H.

    1992-05-01

    The loss parameters of the ducts in the Photon Factory (PF) storage ring were evaluated using the wire method and the code TBCI. Both the measurement and the calculation were done for a different bunch length (σ) ranging from 23 to 80 ps. The PF ring impedance was estimated to be |Z/n|=3.2 Ω using the broadband impedance model. The major contribution to the impedance comes from the bellows and the gate valve sections. Improvements of these components will lower the ring impedance by half. (author)

  6. Tinkering at the main-ring lattice

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuma, S.

    1982-08-23

    To improve production of usable antiprotons using the proton beam from the main ring and the lossless injection of cooled antiprotons into the main ring, modifications of the main ring lattice are recommended.

  7. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    During the Nobel prize-winning UA1 experiment, scientists in the control room used to ring a bell if a particularly interesting event had occurred. Today, the “CMS Exotica hotline” routine produces a daily report that lists the exotic events that were recorded the day before.   Display of an event selected by the Exotica routine. Take just a very small fraction of the available data (max. 5%); define the events that you want to keep and set the parameters accordingly; run the Exotica routine and only look at the very few images that the system has selected for you. This is the recipe that a small team of CMS researchers has developed to identify the signals coming from possible new physics processes. “This approach does not replace the accurate data analysis on the whole set of data. However, it is a very fast and effective way to focus on just a few events that are potentially very interesting”, explains Maurizio Pierini (CERN), who developed the...

  8. Moving ring reactor 'Karin-1'

    International Nuclear Information System (INIS)

    1983-12-01

    The conceptual design of a moving ring reactor ''Karin-1'' has been carried out to advance fusion system design, to clarify the research and development problems, and to decide their priority. In order to attain these objectives, a D-T reactor with tritium breeding blanket is designed, a commercial reactor with net power output of 500 MWe is designed, the compatibility of plasma physics with fusion engineering is demonstrated, and some other guideline is indicated. A moving ring reactor is composed mainly of three parts. In the first formation section, a plasma ring is formed and heated up to ignition temperature. The plasma ring of compact torus is transported from the formation section through the next burning section to generate fusion power. Then the plasma ring moves into the last recovery section, and the energy and particles of the plasma ring are recovered. The outline of a moving ring reactor ''Karin-1'' is described. As a candidate material for the first wall, SiC was adopted to reduce the MHD effect and to minimize the interaction with neutrons and charged particles. The thin metal lining was applied to the SiC surface to solve the problem of the compatibility with lithium blanket. Plasma physics, the engineering aspect and the items of research and development are described. (Kako, I.)

  9. Quantum Fourier Transform Over Galois Rings

    OpenAIRE

    Zhang, Yong

    2009-01-01

    Galois rings are regarded as "building blocks" of a finite commutative ring with identity. There have been many papers on classical error correction codes over Galois rings published. As an important warm-up before exploring quantum algorithms and quantum error correction codes over Galois rings, we study the quantum Fourier transform (QFT) over Galois rings and prove it can be efficiently preformed on a quantum computer. The properties of the QFT over Galois rings lead to the quantum algorit...

  10. Polarized particles in storage rings

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

    1977-01-01

    Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

  11. Researches on the Piston Ring

    Science.gov (United States)

    Ehihara, Keikiti

    1944-01-01

    In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and

  12. Soft Congruence Relations over Rings

    Science.gov (United States)

    Xin, Xiaolong; Li, Wenting

    2014-01-01

    Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft congruence relations by using the soft set theory. The notions of soft quotient rings, generalized soft ideals and generalized soft quotient rings, are introduced, and several related properties are investigated. Also, we obtain a one-to-one correspondence between soft congruence relations and idealistic soft rings and a one-to-one correspondence between soft congruence relations and soft ideals. In particular, the first, second, and third soft isomorphism theorems are established, respectively. PMID:24949493

  13. Distributively generated matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-04-01

    It is known that if R is a near ring with identity then (I,+) is abelian if (I + ,+) is abelian and (I,+) is abelian if (I*,+) is abelian [S.J. Abbasi, J.D.P. Meldrum, 1991]. This paper extends these results. We show that if R is a distributively generated near ring with identity then (I,+) is included in Z(R), the center of R, if (I + ,+) is included in Z(M n (R)), the center of matrix near ring M n (R). Furthermore (I,+) is included in Z(R) if (I*,+) is included in Z(M n (R)). (author). 5 refs

  14. SMARANDACHE NON-ASSOCIATIVE RINGS

    OpenAIRE

    Vasantha, Kandasamy

    2002-01-01

    An associative ring is just realized or built using reals or complex; finite or infinite by defining two binary operations on it. But on the contrary when we want to define or study or even introduce a non-associative ring we need two separate algebraic structures say a commutative ring with 1 (or a field) together with a loop or a groupoid or a vector space or a linear algebra. The two non-associative well-known algebras viz. Lie algebras and Jordan algebras are mainly built using a vecto...

  15. High-resolution spectroscopy of deeply-bound pionic atoms in heavy nuclei by pion-transfer reactions of inverse kinematics using the GSI cooler ring ESR

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu.

    1991-02-01

    Many studies published in the past are reviewed first in relation to high-resolution spectroscopy of deeply-bound pionic atoms in heavy nuclei. The report then describes a procedure for applying the method of inverse kinematics to the case of (d, 3 He) reactions. The (d, 3 He) reaction in inverse kinematics is feasible from practical viewpoints. Thus a discussion is made of the inverse kinematics in which a heavy-ion beam ( 208 Pb for instance) with a projectile kinetic energy hits a deuteron target and ejected recoil 3 He nuclei are measured in the forward direction. The recoil momentum is calculated as a function of the Q value. Analysis shows that the recoil spectroscopy with inverse kinematics can be applied to the case of (d, 3 He) reaction, which will yield a very high mass resolution. The experimental setup for use in the first stage is then outlined, and a simple detector configuration free of magnetic field is discussed. These investigations demonstrate that the (d, 3 He) reaction in inverse kinematics provides a promising tool for obtaining high-resolution spectra of deeply-bound pionic atoms. (N.K.)

  16. A versatile local control system for the LEIR/AD electron cooler

    CERN Document Server

    MacCaferri, R

    1999-01-01

    With the end of antiproton physics at LEAR in 1996, the electron cooling device was modified in order that it could be used for experiments with lead ions in 1997 in LEIR and then for installation in the AD machine the following year. As a consequence, as well as the mechanical modifications to the cooler, the control system also needed to be upgraded and it was decided to build a system that could run either from a PC or from a Workstation as used in the accelerator control rooms. This turned out to be the most efficient solution as no support was given for the maintenance of the old control system during the experiments with lead ions. The PC system was realised during the shutdown before the machine experiments started, leaving time during the rest of 1997 to build the VME interface for installation in the AD. In this paper the hardware and software implementations of this new control system are described and some ideas for the near future are also presented.

  17. Methodology on sizing and selecting thermoelectric cooler from different TEC manufacturers in cooling system design

    International Nuclear Information System (INIS)

    Tan, F.L.; Fok, S.C.

    2008-01-01

    The search and selection for a suitable thermoelectric cooler (TEC) to optimize a cooling system design can be a tedious task as there are many product ranges from several TEC manufacturers. Although the manufacturers do provide proprietary manuals or electronic search facilities for their products, the process is still cumbersome as these facilities are incompatible. The electronic facilities often have different user interfaces and functionalities, while the manual facilities have different presentations of the performance characteristics. This paper presents a methodology to assist the designer to size and select the TECs from different manufacturers. The approach will allow designers to find quickly and to evaluate the devices from different TEC manufacturers. Based on the approach, the article introduces a new operational framework for an Internet based thermoelectric cooling system design process that would promote the interaction and collaboration between the designers and TEC manufacturers. It is hoped that this work would be useful for the advancement of future tools to assist designers to develop, analyze and optimize thermoelectric cooling system design in minimal time using the latest TECs available on the market

  18. Feasibility of a solar-assisted winter air-conditioning system using evaporative air-coolers

    Energy Technology Data Exchange (ETDEWEB)

    El-Awad, Mohamed M. [Mechanical Engineering Department, the University of Khartoum, P.O. Box 321 Khartoum (Sudan)

    2011-07-01

    The paper presents a winter air-conditioning system which is suitable for regions with mildly cold but dry winters. The system modifies the evaporative air-cooler that is commonly used for summer air-conditioning in such regions by adding a heating process after the humidification process. The paper describes a theoretical model that is used to estimate the system's water and energy consumption. It is shown that a 150-LPD solar heater is adequate for air-conditioning a 500 ft3/min (14.4 m3/min) air flow rate for four hours of operation. The maximum air-flow rate that can be heated by a single solar water-heater for four hours of operation is about 900-cfm, unless a solar water heater large than a 250-LPD heater is used. For the 500 ft3/min air flow rate the paper shows that the 150, 200, 250 and 300 LPD solar water-heaters can provide air-conditioning for 4, 6, 8 and 10 hours, respectively, while consuming less energy than the equivalent refrigerated-type air-conditioner.

  19. Drought and Cooler Temperatures Are Associated with Higher Nest Survival in Mountain Plovers

    Directory of Open Access Journals (Sweden)

    Victoria J. Dreitz

    2012-06-01

    Full Text Available Native grasslands have been altered to a greater extent than any other biome in North America. The habitats and resources needed to support breeding performance of grassland birds endemic to prairie ecosystems are currently threatened by land management practices and impending climate change. Climate models for the Great Plains prairie region predict a future of hotter and drier summers with strong multiyear droughts and more frequent and severe precipitation events. We examined how fluctuations in weather conditions in eastern Colorado influenced nest survival of an avian species that has experienced recent population declines, the Mountain Plover (Charadrius montanus. Nest survival averaged 27.2% over a 7-yr period (n = 936 nests and declined as the breeding season progressed. Nest survival was favored by dry conditions and cooler temperatures. Projected changes in regional precipitation patterns will likely influence nest survival, with positive influences of predicted declines in summer rainfall yet negative effects of more intense rain events. The interplay of climate change and land use practices within prairie ecosystems may result in Mountain Plovers shifting their distribution, changing local abundance, and adjusting fecundity to adapt to their changing environment.

  20. Radiofrequency quadrupole-based beam cooler and buncher for the CANREB project at TRIUMF

    Science.gov (United States)

    Barquest, Brad; Pearson, Matt; Ames, Friedhelm; Dilling, Jens; Gwinner, Gerald; Kanungo, Rituparna; Kruecken, Reiner

    2016-09-01

    A new radiofrequency quadrupole-based ion beam cooler and buncher (BCB) and pulsed drift tube (PDT) have been designed as part of the CANREB project at TRIUMF. The BCB is designed to accept continuous 60 keV rare isotope beams from the ARIEL or ISAC production targets and efficiently deliver low-emittance, bunched beams of up to 107 ions per bunch to an electron beam ion source (EBIS) to charge-breed the bunch for post-acceleration. The PDT will adjust the energy of the bunched beam from 60 keV to 10-14 keV for injection into the EBIS. The injection energy is determined by the acceptance of the post-accelerating RFQ. The design of the BCB is nearing completion, and fabrication and assembly effort will proceed shortly. In addition, a PDT prototype is under development to test that the design concept satisfies the voltage and switching time requirements. Design features of the BCB and PDT will be discussed, and an update on BCB assembly and PDT testing progress will be presented. CANREB is funded by CFI, NSRIT, Manitoba Research and Innovation Fund, AAPS, Saint Mary's U, U of Manitoba and TRIUMF. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada.

  1. A novel magnetic suspension cum linear actuator system for satellite cryo coolers

    International Nuclear Information System (INIS)

    Sivadasan, K.K.

    1994-01-01

    Stirling cycle cryogenic coolers have been widely used for device cooling in satellites. Various types of magnetic bearings and linear actuators find application in such systems. The most widely used configurations have two-axis-radially-active suspension stations placed at either ends of a reciprocating shaft in the compression and expansion sections. Separate or integral liner motors are provided in each section for axial shaft movement. It may be noted that such configurations are rather complicated and less reliable because of the presence of numerous electro-mechanical components, sensors and electronic servo channels. In this paper, a simple and reliable scheme is suggested which axially stabilizes and linearly perturbs the piston so that the need for a separate motor for axial actuation can be totally dispensed with. The piston is radially supported by passive repulsive bearings. In the axial direction, a servo actuator ''balances'' the piston and also actuates it bi-directionally. Implemented of this ''bearing cum motor theme,'' reduces the number of electromechanical and electronic components required to operate the system and hence minimizes the chances of system failure. Apart from this, the system's power consumption is reduced and efficiency is improved as electrical heating losses caused by quiescent-operating currents are removed and electromagnetic losses on the moving parts are minimized. The necessary system parameters have been derived using finite element analysis techniques. Finally, the proposed design is validated by computer-aided system simulation

  2. Geometric optimization of thermoelectric coolers in a confined volume using genetic algorithms

    International Nuclear Information System (INIS)

    Cheng, Y.-H.; Lin, W.-K.

    2005-01-01

    The demand for thermoelectric coolers (TEC) has grown significantly because of the need for a steady, low-temperature operating environment for various electronic devices such as laser diodes, semiconductor equipment, infrared detectors and others. The cooling capacity and its coefficient of performance (COP) are both extremely important in considering applications. Optimizing the dimensions of the TEC legs provides the advantage of increasing the cooling capacity, while simultaneously considering its minimum COP. This study proposed a method of optimizing the dimensions of the TEC legs using genetic algorithms (GAs), to maximize the cooling capacity. A confined volume in which the TEC can be placed and the technological limitation in manufacturing a TEC leg were considered, and three parameters - leg length, leg area and the number of legs - were taken as the variables to be optimized. The constraints of minimum COP and maximum cost of the material were set, and a genetic search was performed to determine the optimal dimensions of the TEC legs. This work reveals that optimizing the dimensions of the TEC can increase its cooling capacity. The results also show that GAs can determine the optimal dimensions according to various input currents and various cold-side operating temperatures

  3. Development of a radio-frequency quadrupole cooler for high beam currents

    Science.gov (United States)

    Boussaid, Ramzi; Ban, G.; Quéméner, G.; Merrer, Y.; Lorry, J.

    2017-12-01

    The SHIRaC prototype is a recently developed radio-frequency quadrupole (RFQ) beam cooler with an improved optics design to deliver the required beam quality to a high resolution separator (HRS). For an isobaric separation of isotopes, the HRS demands beams with emittance not exceeding 3 π mm mrad and longitudinal energy spread ˜1 eV . Simulation studies showed a significant contribution of the buffer gas diffusion, space charge effect and mainly the rf fringe field to degrade the achieved beam quality at the RFQ exit. A miniature rf quadrupole (μ RFQ ) has been implemented at that exit to remove the degrading effects and provide beams with 1 eV of energy spread and around 1.75 π mm mrad of emittance for 4 Pa gas pressure. This solution enables also to transmit more than 60% of the incoming ions for currents up to 1 μ A . Detailed studies of this development are presented and discussed in this paper. Transport of beams from SHIRaC towards the HRS has been done with an electrostatic quadrupole triplet. Simulations and first experimental tests showed that more than 95% of ions can reach the HRS. Because SPIRAL-2 beams are of high current and very radioactive, the buffer gas will be highly contaminated. Safe maintenance of the SHIRaC beam line needs exceptional treatment of radioactive contaminants. For that, special vinyl sleep should be mounted on elements to be maintained. A detailed maintenance process will be presented.

  4. Optimization Of Thermo-Electric Coolers Using Hybrid Genetic Algorithm And Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Khanh Doan V.K.

    2014-06-01

    Full Text Available Thermo-electric Coolers (TECs nowadays are applied in a wide range of thermal energy systems. This is due to their superior features where no refrigerant and dynamic parts are needed. TECs generate no electrical or acoustical noise and are environmentally friendly. Over the past decades, many researches were employed to improve the efficiency of TECs by enhancing the material parameters and design parameters. The material parameters are restricted by currently available materials and module fabricating technologies. Therefore, the main objective of TECs design is to determine a set of design parameters such as leg area, leg length and the number of legs. Two elements that play an important role when considering the suitability of TECs in applications are rated of refrigeration (ROR and coefficient of performance (COP. In this paper, the review of some previous researches will be conducted to see the diversity of optimization in the design of TECs in enhancing the performance and efficiency. After that, single-objective optimization problems (SOP will be tested first by using Genetic Algorithm (GA and Simulated Annealing (SA to optimize geometry properties so that TECs will operate at near optimal conditions. Equality constraint and inequality constraint were taken into consideration.

  5. Evaluation on Cooling Performance of Containment Fan Cooler during Design Basis Accident with Loss of Offsite Power for Kori 3 and 4 Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Bok; Lee, Sang Won [Korea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of); Park, Young Chan [Atomic Creative Technology Co., LTD., Daejeon (Korea, Republic of)

    2007-10-15

    The purpose of this study is to evaluate cooling performance of containment fan cooler units and to review a technical background related to Generic Letter 96-06. In case that design basis accident (DBA) and loss of offsite power (LOOP) occurs, component cooling water (CCW) pumps cannot provide the cooling water source to fan cooler units while fan coolers coast down. Fan cooler units and CCW pumps are restarted by emergency diesel generator (EDG) operation and it takes about 30 seconds. In this scenario, before the EDG restarts and CCW flowrate is restored, heated air in the containment passes through coil of fan cooler units without cooling water source. In this situation, the boiling of water in the fan cooler units may occur. Restarting of CCW pumps may bring about condensation by injected cooling water and water hammer may occur. This thermal-hydraulic effect is sensitive to system configuration, i.e system pressure, containment pressure/temperature, EDG restarting time, etc. In this study, the evaluation of containment fan cooler units was performed for Kori 3 and 4 nuclear power plant.

  6. Implementation of a new blood cooler insert and tracking technology with educational initiatives and its effect on reducing red blood cell wastage.

    Science.gov (United States)

    Fadeyi, Emmanuel A; Emery, Wanda; Simmons, Julie H; Jones, Mary Rose; Pomper, Gregory J

    2017-10-01

    The objective was to report a successful implementation of a blood cooler insert and tracking technology with educational initiatives and its effect on reducing red blood cell (RBC) wastage. The blood bank database was used to quantify and categorize total RBC units issued in blood coolers from January 2010 to December 2015 with and without the new inserts throughout the hospital. Radiofrequency identification tags were used with special software to monitor blood cooler tracking. An educational policy on how to handle the coolers was initiated. Data were gathered from the software that provided a real-time location monitoring of the blood coolers with inserts throughout the institution. The implementation of the blood cooler with inserts and tracking device reduced mean yearly RBC wastage by fourfold from 0.64% to 0.17% between 2010 and 2015. The conserved RBCs corresponded to a total cost savings of $167,844 during the 3-year postimplementation period. The implementation of new blood cooler inserts, tracking system, and educational initiatives substantially reduced the mean annual total RBC wastage. The cost to implement this initiative may be small if there is an existing institutional infrastructure to monitor and track hospital equipment into which the blood bank intervention can be adapted when compared to the cost of blood wastage. © 2017 AABB.

  7. Prototype moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1982-01-01

    We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power

  8. Autumn study on storage rings

    CERN Multimedia

    1974-01-01

    The first two weeks of October have seen storage ring people from accelerator Laboratories throughout the world at CERN to study the fundamental problems of very high energy protonproton colliding beam machines.

  9. Minimal Gromov-Witten rings

    International Nuclear Information System (INIS)

    Przyjalkowski, V V

    2008-01-01

    We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants

  10. Cosmic rings from colliding galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Mitton, S

    1976-11-18

    Research on two ring galaxies has led to the proposal of an interaction model to account for the rings. It is envisaged that this class of galaxy is created when a compact galaxy crashes through the disc of a spiral galaxy. The results of a spectroscopic investigation of the galaxy known as the Cartwheel and of another ring galaxy 11 NZ 4 are discussed. The general picture of ring galaxies which emerges from these studies of a massive starry nucleus with a necklace of emitting gas and some spokes and along the spin axis of the wheel a small companion galaxy that is devoid of interstellar gas. An explanation of these properties is considered.

  11. Ring lasers - a brief history

    Science.gov (United States)

    Klein, Tony

    2017-10-01

    Used these days in inertial navigation, ring lasers are also used in recording the tiniest variations in the Earth's spin, as well in detecting earthquakes and even the drift of continents. How did it all begin?

  12. Ring insertions as light sources

    International Nuclear Information System (INIS)

    Green, G.K.

    1975-01-01

    Bending magnets can be inserted in the long straight sections of electron storage rings to produce synchrotron radiation. If the design is carefully proportioned, the bending magnets create only a small perturbation of the properties of the ring. The resulting spectra have favorable optical properties as sources for spectroscopy and diffraction studies. The characteristics of the source are discussed, and the geometrical requirements of the magnets are presented

  13. Collector ring project at FAIR

    International Nuclear Information System (INIS)

    Dolinskii, A; Blell, U; Dimopoulou, C; Gorda, O; Leibrock, H; Litvinov, S; Laier, U; Schurig, I; Weinrich, U; Berkaev, D; Koop, I; Starostenko, A; Shatunov, P

    2015-01-01

    The collector ring is a dedicated ring for fast cooling of ions coming from separators at the FAIR project. To accommodate optimal technical solutions, a structure of a magnet lattice was recently reviewed and modified. Consequently, more appropriate technical solutions for the main magnets could be adopted. A general layout and design of the present machine is shown. The demanding extraction schemes have been detailed and open design issues were completed. (paper)

  14. Synlig læring

    DEFF Research Database (Denmark)

    Brandsen, Mads

    2017-01-01

    Introduktionen af John Hatties synlig læring i den danske skoleverden møder stadig meget kritik. Mange lærere og pædagoger oplever synlig læring som en tornado, der vil opsuge og ødelægge deres særlige danske udgave af den kontinentale dannelsestænkning, didaktik og pædagogik. Spørgsmålet er om...

  15. The circular RFQ storage ring

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1998-01-01

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features used in a conventional storage ring and an ion trap, and is basically a linear RFQ bend on itself. In summary the advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  16. The Circular RFQ Storage Ring

    International Nuclear Information System (INIS)

    Ruggiero, A. G.

    1999-01-01

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features of conventional storage rings and ion traps, and is basically a linear RFQ bent on itself. The advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  17. Electrically charged dilatonic black rings

    International Nuclear Information System (INIS)

    Kunduri, Hari K.; Lucietti, James

    2005-01-01

    In this Letter we present (electrically) charged dilatonic black ring solutions of the Einstein-Maxwell-dilaton theory in five dimensions and we consider their physical properties. These solutions are static and as in the neutral case possess a conical singularity. We show how one may remove the conical singularity by application of a Harrison transformation, which physically corresponds to supporting the charged ring with an electric field. Finally, we discuss the slowly rotating case for arbitrary dilaton coupling

  18. Low emittance electron storage rings

    Science.gov (United States)

    Levichev, E. B.

    2018-01-01

    Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

  19. Resonance capture and Saturn's rings

    International Nuclear Information System (INIS)

    Patterson, C.W.

    1986-05-01

    We have assigned the resonances apparently responsible for the stabilization of the Saturn's shepherd satellites and for the substructure seen in the F-ring and the ringlets in the C-ring. We show that Saturn's narrow ringlets have a substructure determined by three-body resonances with Saturn's ringmoons and the sun. We believe such resonances have important implications to satellite formation. 17 refs., 1 fig., 1 tab

  20. Energy spectra of quantum rings.

    Science.gov (United States)

    Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M

    2001-10-25

    Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.

  1. Improving eco-sustainable characteristics and energy efficiency of evaporative fluid cooler via experimental and numerical study

    Directory of Open Access Journals (Sweden)

    Rašković Predrag O.

    2008-01-01

    Full Text Available This paper presents an on-going research project that aims to identify possibilities for wider use of evaporative cooling in process industry, especially the use of evaporative fluid cooler units. Experimental study is performed on small scale evaporative fluid cooler, while the correlation based model has been carried out to explore the detailed heat and mass transfer processes inside this unit. Numerical integration of mathematical model is executed by new approach, based on differential, collocation Simpson method. Proposed models have been verified by comparing the computed results with those obtained by the experimental measurements. The results of research will enable the creation of more comprehensive simulation software, with wider range of operating and construction parameters.

  2. Growth Rate Potential of Juvenile Sockeye Salmon in Warmer and Cooler Years on the Eastern Bering Sea Shelf

    Directory of Open Access Journals (Sweden)

    Edward V. Farley

    2009-01-01

    Full Text Available A spatially explicit bioenergetics model was used to predict juvenile sockeye salmon Oncorhynchus nerka growth rate potential (GRP on the eastern Bering Sea shelf during years with cooler and warmer spring sea surface temperatures (SSTs. Annual averages of juvenile sockeye salmon GRP were generally lower among years with cooler SSTs and generally higher in offshore than nearshore regions of the eastern Bering Sea shelf during years with warmer SSTs. Juvenile sockeye salmon distribution was significantly (P<.05 related to GRP and their prey densities were positively related to spring SST (P<.05. Juvenile sockeye salmon GRP was more sensitive to changes in prey density and observed SSTs during years when spring SSTs were warmer (2002, 2003, and 2005. Our results suggest that the pelagic productivity on the eastern Bering Sea shelf was higher during years with warmer spring SSTs and highlight the importance of bottom-up control on the eastern Bering Sea ecosystem.

  3. Developments at an electrostatic cryogenic storage ring for electron-cooled keV energy ion beams

    International Nuclear Information System (INIS)

    Vogel, Stephen

    2016-01-01

    This work is devoted to final setup activities and the commissioning of an electrostatic cryogenic storage ring (CSR) at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg. The first cryogenic operation of CSR in 2015 has been documented and characterized using a set of non-destructive beam diagnostic tools developed within this work. These are (1) the current pick-up system for the determination of the current of the stored ion beam and its velocity, (2) a position pick-up system for measuring the transverse position of the ion beam center at six symmetric locations of the storage ring circumference, and (3) a Schottky pick-up system for the monitoring of coasting ion beams. Despite the requirements imposed by the cryogenic operation, the developed diagnostic system demonstrated its full functionality. First characterizations of the storage ring properties and the performance of the diagnostic system are presented. Based on previous work, an electron cooling system for CSR has been developed and largely realized. With the implementation into CSR in 2016, the electron cooler will enhance the storage ring into a unique experimental facility for electron-ion collision studies. With this CSR is on the track to become the first cryogenic storage ring featuring actively cooled ion beams.

  4. Accretion in Saturn's F Ring

    Science.gov (United States)

    Meinke, B. K.; Esposito, L. W.; Stewart, G.

    2012-12-01

    Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

  5. Double acting stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1986-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  6. Study for ILC Damping Ring at KEKB

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; /KEK, Tsukuba; Pivi, M.; /SLAC

    2011-11-04

    ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.

  7. Vacuum packaging of InGaAs focal plane array with four-stage thermoelectric cooler

    Science.gov (United States)

    Mo, De-feng; Liu, Da-fu; Yang, Li-yi; Xu, Qin-fei; Li, Xue

    2013-09-01

    The InGaAs focal plane array (FPA) detectors, covering the near-infrared 1~2.4 μm wavelength range, have been developed for application in space-based spectroscopy of the Earth atmosphere. This paper shows an all-metal vacuum package design for area array InGaAs detector of 1024×64 pixels, and its architecture will be given. Four-stage thermoelectric cooler (TEC) is used to cool down the FPA chip. To acquire high heat dissipation for TEC's Joule-heat, tungsten copper (CuW80) and kovar (4J29) is used as motherboard and cavity material respectively which joined by brazing. The heat loss including conduction, convection and radiation is analyzed. Finite element model is established to analyze the temperature uniformity of the chip substrate which is made of aluminum nitride (AlN). The performance of The TEC with and without heat load in vacuum condition is tested. The results show that the heat load has little influence to current-voltage relationship of TEC. The temperature difference (ΔT) increases as the input current increases. A linear relationship exists between heat load and ΔT of the TEC. Theoretical analysis and calculation show that the heat loss of radiation and conduction is about 187 mW and 82 mW respectively. Considering the Joule-heat of readout circuit and the heat loss of radiation and conduction, the FPA for a 220 K operation at room temperature can be achieved. As the thickness of AlN chip substrate is thicker than 1 millimeter, the temperature difference can be less than 0.3 K.

  8. Application of cascading thermoelectric generator and cooler for waste heat recovery from solid oxide fuel cells

    International Nuclear Information System (INIS)

    Zhang, Houcheng; Kong, Wei; Dong, Feifei; Xu, Haoran; Chen, Bin; Ni, Meng

    2017-01-01

    Highlights: • Cascading thermoelectric devices are proposed to recover waste heat from SOFCs. • A theoretical model is developed to analyze the new hybrid system performance. • Performance parameters for evaluating the hybrid system are specified. • Feasibility and effectiveness of the proposed system are demonstrated. • Effects of some important parameters on the system performance are discussed. - Abstract: Besides electricity generation, solid oxide fuel cells (SOFCs) produce a significant amount of waste heat, which needs to be immediately removed to ensure the normal operation of SOFCs. If the waste heat is recovered through bottoming thermal devices, the global efficiency of SOFCs can be improved. In this study, a new hybrid system mainly consisting of a thermoelectric generator, a thermoelectric cooler and an SOFC is proposed to recover the waste heat from SOFC for performance enhancement. The thermodynamic and electrochemical irreversible losses in each component are fully considered. An analytical relationship between the SOFC operating current density and the thermoelectric devices dimensionless electric current is derived, from which the range of SOFC operating current density that permits the thermoelectric devices to effectively work is determined. The equivalent power output and efficiency for the hybrid system are specified under different operating current density regions. The feasibility and effectiveness are illustrated by comparing the proposed hybrid system with the stand-alone SOFC. It is found that the power density and efficiency of the proposed system allow 2.3% and 4.6% larger than that of the stand-alone SOFC, respectively. Finally, various parametric analyses are performed to discuss the effects of some design and operation parameters on the hybrid system performance.

  9. Impact of an Ultraviolet Reactor on the Improvement of Air Quality Leaving a Direct Evaporative Cooler

    Directory of Open Access Journals (Sweden)

    Wonjun Kim

    2018-04-01

    Full Text Available The purpose of this study is to improve microbial air quality by improving water quality, particularly concerning microbiological aspects, by applying an ultraviolet water purifier system to a direct evaporative cooling (DEC system. A direct evaporative cooler is an air cooling technique that uses the evaporation of water. Most DECs recirculate water to reduce water use. Evaporative cooling pads and water are biologically contaminated by recirculating water. This contamination can develop into air contamination and cause respiratory illnesses in occupants. It is necessary to use sterilized water in a DEC to prevent respiratory diseases and maintain air quality. In this study, we examine whether improvements in water quality in a DEC affect air quality by dividing experiments into a control group (Control and a treated group (UV-treated. In the control group, the degree of contamination was measured when a DEC operated for four weeks without ultraviolet water treatment. In UV-treated, the degree of contamination was measured when UV water treatment was applied to a DEC for four weeks. In both Control and UV-treated, microbes were sampled from the water, the evaporative cooling pad surface, and the DEC inlet and outlet air samples in order to compare the levels of contamination. The surface was measured once at four points, and the air was measured four times at two points. A comparison of the two experiments indicated that the degree of microbial contamination of water and air was significantly reduced in the UV-treated group when compared to that in the control group. When the pollution degree of the evaporative cooling pad was compared to the degree of air pollution, it was difficult to obtain a correlation between the two factors, although the results confirmed that the contamination of the evaporative cooling pad caused water pollution. Therefore, it is necessary to operate a water treatment system to maintain the clean air in DECs.

  10. Thermoelectric mini cooler coupled with micro thermosiphon for CPU cooling system

    International Nuclear Information System (INIS)

    Liu, Di; Zhao, Fu-Yun; Yang, Hong-Xing; Tang, Guang-Fa

    2015-01-01

    In the present study, a thermoelectric mini cooler coupling with a micro thermosiphon cooling system has been proposed for the purpose of CPU cooling. A mathematical model of heat transfer, depending on one-dimensional treatment of thermal and electric power, is firstly established for the thermoelectric module. Analytical results demonstrate the relationship between the maximal COP (Coefficient of Performance) and Q c with the figure of merit. Full-scale experiments have been conducted to investigate the effect of thermoelectric operating voltage, power input of heat source, and thermoelectric module number on the performance of the cooling system. Experimental results indicated that the cooling production increases with promotion of thermoelectric operating voltage. Surface temperature of CPU heat source linearly increases with increasing of power input, and its maximum value reached 70 °C as the prototype CPU power input was equivalent to 84 W. Insulation between air and heat source surface can prevent the condensate water due to low surface temperature. In addition, thermal performance of this cooling system could be enhanced when the total dimension of thermoelectric module matched well with the dimension of CPU. This research could benefit the design of thermal dissipation of electronic chips and CPU units. - Highlights: • A cooling system coupled with thermoelectric module and loop thermosiphon is developed. • Thermoelectric module coupled with loop thermosiphon can achieve high heat-transfer efficiency. • A mathematical model of thermoelectric cooling is built. • An analysis of modeling results for design and experimental data are presented. • Influence of power input and operating voltage on the cooling system are researched

  11. Influence of constructive parameters on the performance of two indirect evaporative cooler prototypes

    International Nuclear Information System (INIS)

    Tejero-González, Ana; Andrés-Chicote, Manuel; Velasco-Gómez, Eloy; Rey-Martínez, Francisco Javier

    2013-01-01

    Two equally-sized cross-flow heat-exchanger prototypes have been designed with a total heat exchange area of 6 m 2 and 3 m 2 respectively, constructed with polycarbonate hollow panels of different cross section. They are connected into a heat-recovery cycle within the whole experimental setup constructed for the tests, which mainly consists of: an Air Handling Unit to simulate the outdoor airstream conditions, a conditioned climate chamber, and a water circuit to provide the water supply required. They have been experimentally characterised in two operating modes in order to determine how evaporative cooling improves heat recovery in each case, focussing on the influence of modifying the constructive characteristics. To perform the evaporative cooling process, water is supplied to the exhaust airstream. Results are studied considering how constructive issues, outdoor air volume flow rate and temperature, as well as operating mode influence on the performance obtained. An Analysis of Variance shows how outdoor airflow has a key role in the performance of the systems; whereas entering outdoor air temperature determines cooling capacities. Improvements introduced by larger heat exchange areas compensate with their corresponding smaller cross sections, which hinder water – air distribution on the exhaust air side of the heat exchanger. Finally, these small devices achieve cooling capacities of up to 800 W, being able to partly support ventilation load and achieving around 50% of energy saving in ventilation cooling. -- Highlights: ► Two indirect evaporative cooler prototypes are experimentally characterised. ► Evaporative cooling improves heat recovery. ► Influence on performance of different heat exchange area and cross section is studied. ► Larger cross section favours evaporative cooling process. ► Effect of smaller heat exchange area is compensated by that of larger cross section

  12. Solar chimney integrated with passive evaporative cooler applied on glazing surfaces

    International Nuclear Information System (INIS)

    Al Touma, Albert; Ghali, Kamel; Ghaddar, Nesreen; Ismail, Nagham

    2016-01-01

    This study investigates the performance of a hybrid system applied on glazing surfaces for reducing the space cooling load and radiation asymmetry. The proposed system combines the principles of passive evaporative cooling with the natural buoyant flow in solar chimneys to entrain outdoor air and attenuate the window surface temperature. A predictive heat and mass transport model combining the evaporative cooler, glazing section, solar chimney and an office space is developed to study the system performance in harshly hot climates. The developed model was validated through experiments conducted in a twin climatic chamber for given ambient temperature, humidity, and solar radiation conditions. Good agreement was found between the measured and the predicted window temperatures and space loads at maximum discrepancy lower than 4.3%. The proposed system is applied to a typical office space to analyze its effectiveness in reducing the window temperature, the space load and radiation asymmetry, while maintaining the indoor comfort conditions. Results have shown that the system is reduced the space load by −19.8% and attenuated the radiation asymmetry significantly for office spaces having window-to-wall ratio of 40% in climate of Riyadh, KSA. The system performance diminished when applied in locations suffering from humid weather climates. - Highlights: • A passive evaporative-cooled solar chimney system is introduced to decrease window temperature. • A mathematical model is developed of the system to predict induce air flow and window surface temperature. • The model is validated with experiments in twin room climatic chamber and using artificial solar lamps. • The system reduces window maximum temperature by 5 °C in the hot dry climate of Riyadh, KSA. • It reduced the space load by 19.4% for office spaces at window-to-wall ratio of 40% in Riyadh, KSA.

  13. Manipulation of vortex rings for flow control

    International Nuclear Information System (INIS)

    Toyoda, Kuniaki; Hiramoto, Riho

    2009-01-01

    This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)

  14. Structure and dynamics of ringed galaxies

    International Nuclear Information System (INIS)

    Buta, R.J.

    1984-01-01

    In many spiral and SO galaxies, single or multiple ring structures are visible in the disk. These inner rings (r), outer rings (R), and nuclear rings (nr) were investigated by means of morphology, photometry, and spectroscopy in order to provide basic data on a long neglected phenomenon. The metric properties of each ring are investigated and found to correlate with the structure of the parent galaxy. When properly calibrated, inner rings in barred (SB) systems can be used as geometric extragalactic distance indicators to distances in excess of 100 Mpc. Other statistics are presented that confirm previous indications that the rings have preferred shapes, relative sizes, and orientations with respect to bars. A survey is made of the less homogeneous non-barred (SA) ringed systems, and the causes of the inhomogeneity are isolated. It is shown that rings can be identified in multiple-ring SA systems that are exactly analogous to those in barred spirals

  15. Experimental testing of a small sorption air cooler using composite material made from natural siliceous shale and chloride

    International Nuclear Information System (INIS)

    Liu, Hongzhi; Nagano, Katsunori; Morita, Atsushi; Togawa, Junya; Nakamura, Makoto

    2015-01-01

    A sorption air cooler experimental setup including a reactor and fin tube condenser/evaporator was built. The reactor was developed with inner copper fins and dual layers of curing copper meshes. Composite material made by impregnating LiCl into the mesopores of Wakkanai Siliceous Shale (WSS) micropowders was packed between the intervals of two fins. Heat transfer was enhanced by the attached fins, and the dual layers of curing meshes installed between each interval of two fins were designed to improve the sorbate mass transfer. On the other hand, the fin-tube evaporator/condenser with fins outside is valuable for improving the convective heat transfer between the functional water inside the evaporator/condenser and the flowing outside heat transfer medium, air. The sorption capacity of the composite material increased dramatically after being impregnated with LiCl. Among the four tested samples, WSS + 40 wt% LiCl exhibits the best performance. A regeneration temperature of 80 °C appears to be optimal for obtaining both a high COP and high specific cooling power. A lower condensation temperature can increase the cooling power. The sorption and desorption times of 60 min yield a reasonable compromise between cooling COP and mass specific cooling powers. The developed sorption air cooler system using WSS + 40 wt% LiCl can store heat at temperatures below 100 °C and produce cooling energy with a cooling coefficient of performance (COP) of approximately 0.3. - Highlights: • Mesoporous composite material was developed using natural siliceous shale and LiCl. • Properties of the developed material were measured. • A sorption air cooler experimental setup including an inner-fin reactor and a fin tube condenser/evaporator was built. • The performance of the composite material in the sorption air cooler was examined. • The sorption air cooler system can produce cooling energy with a cooling COP around 0.3

  16. Pure subrings of the rings

    International Nuclear Information System (INIS)

    Tsarev, Andrei V

    2009-01-01

    Pure subrings of finite rank in the Z-adic completion of the ring of integers and in its homomorphic images are considered. Certain properties of these rings are studied (existence of an identity element, decomposability into a direct sum of essentially indecomposable ideals, condition for embeddability into a csp-ring, etc.). Additive groups of these rings and conditions under which these rings are subrings of algebraic number fields are described. Bibliography: 12 titles.

  17. GOTHIC-IST 6.1b code validation exercises relating to heat removal by dousing and air coolers in CANDU containment

    International Nuclear Information System (INIS)

    Ramachandran, S.; Krause, M.; Nguyen, T.

    2003-01-01

    This paper presents validation results relating to the use of the GOTHIC containment analysis code for CANDU safety analysis. The validation results indicate that GOTHIC predicts heat removal by dousing and air cooler heat transfer with reasonable accuracy. (author)

  18. Primitivity and weak distributivity in near rings and matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-08-01

    This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs

  19. Ring wormholes via duality rotations

    Directory of Open Access Journals (Sweden)

    Gary W. Gibbons

    2016-09-01

    Full Text Available We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy–Voorhees–Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than −c4/4G. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a hole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes, for example by vacuum fluctuations.

  20. HYPERAUTOFLUORESCENT RING IN AUTOIMMUNE RETINOPATHY

    Science.gov (United States)

    LIMA, LUIZ H.; GREENBERG, JONATHAN P.; GREENSTEIN, VIVIENNE C.; SMITH, R. THEODORE; SALLUM, JULIANA M. F.; THIRKILL, CHARLES; YANNUZZI, LAWRENCE A.; TSANG, STEPHEN H.

    2015-01-01

    Purpose To report the presence of a hyperautofluorescent ring and corresponding spectral-domain optical coherence tomography (SD-OCT) features seen in patients with autoimmune retinopathy. Methods All eyes were evaluated by funduscopic examination, full-fleld electroretinography, fundus autofluorescence, and SD-OCT. Further confirmation of the diagnosis was obtained with immunoblot and immunohistochemistry testing of the patient’s serum. Humphrey visual fields and microperimetry were also performed. Results Funduscopic examination showed atrophic retinal pigment epithelium (RPE) associated with retinal artery narrowing but without pigment deposits. The scotopic and photopic full-field electroretinograms were nondetectable in three patients and showed a cone–rod pattern of dysfunction in one patient. Fundus autofluorescence revealed a hyperautofluorescent ring in the parafoveal region, and the corresponding SD-OCT demonstrated loss of the photoreceptor inner segment–outer segment junction with thinning of the outer nuclear layer from the region of the hyperautofluorescent ring toward the retinal periphery. The retinal layers were generally intact within the hyperautofluorescent ring, although the inner segment–outer segment junction was disrupted, and the outer nuclear layer and photoreceptor outer segment layer were thinned. Conclusion This case series revealed the structure of the hyperautofluorescent ring in autoimmune retinopathy using SD-OCT. Fundus autofluorescence and SD-OCT may aid in the diagnosis of autoimmune retinopathy and may serve as a tool to monitor its progression. PMID:22218149

  1. CMB lensing and giant rings

    Energy Technology Data Exchange (ETDEWEB)

    Rathaus, Ben; Itzhaki, Nissan, E-mail: nitzhaki@post.tau.ac.il, E-mail: ben.rathaus@gmail.com [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  2. Proton storage ring summer workshop

    International Nuclear Information System (INIS)

    Lawrence, G.P.; Cooper, R.K.

    1977-10-01

    During the week of August 16, 1976 a Workshop was held at the Los Alamos Scientific Laboratory (LASL) on the Proton Storage Ring (PSR) for the Weapons Neutron Research Facility (WNRF). Written contributions were solicited from each of the participants in the Workshop, and the contributions that were received are presented. The papers do not represent polished or necessarily complete work, but rather represent ''first cuts'' at their respective areas. Topics covered include: (1) background information on the storage ring; (2) WNRF design; (3) rf transient during filling; (4) rf capture; (5) beam bunch compression; (6) transverse space charge limits; (7) transverse resistive instability in the PSR; (8) longitudinal resistive instability; (9) synchrotron frequency splitting; (10) E Quintus Unum--off resonance; (11) first harmonic bunching in the storage ring; (12) kicker considerations; (13) beam extraction; (14) ferrite kicker magnets; and (15) E Quintus Unum: a possible ejection scheme

  3. New Main Ring control system

    International Nuclear Information System (INIS)

    Seino, K.; Anderson, L.; Ducar, R.; Franck, A.; Gomilar, J.; Hendricks, B.; Smedinghoff, J.

    1990-03-01

    The Fermilab Main Ring control system has been operational for over sixteen years. Aging and obsolescence of the equipment make the maintenance difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the Fermilab accelerators except the Main Ring. Modernization of the equipment and standardization of the hardware and software have thus become inevitable. The Tevatron CAMAC serial system has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the accelerator complex. New hardware pieces including intelligent CAMAC modules have been designed to satisfy unique requirements. Fiber optic cable and repeaters have been installed in order to accommodate new channel requirements onto the already saturated communication medium system. 8 refs., 2 figs

  4. Tree rings and radiocarbon calibration

    International Nuclear Information System (INIS)

    Barbetti, M.

    1999-01-01

    Only a few kinds of trees in Australia and Southeast Asia are known to have growth rings that are both distinct and annual. Those that do are therefore extremely important to climatic and isotope studies. In western Tasmania, extensive work with Huon pine (Lagarostrobos franklinii) has shown that many living trees are more than 1,000 years old, and that their ring widths are sensitive to temperature, rainfall and cloud cover (Buckley et al. 1997). At the Stanley River there is a forest of living (and recently felled) trees which we have sampled and measured. There are also thousands of subfossil Huon pine logs, buried at depths less than 5 metres in an area of floodplain extending over a distance of more than a kilometre with a width of tens of metres. Some of these logs have been buried for 50,000 years or more, but most of them belong to the period between 15,000 years and the present. In previous expeditions in the 1980s and 1990s, we excavated and sampled about 350 logs (Barbetti et al. 1995; Nanson et al. 1995). By measuring the ring-width patterns, and matching them between logs and living trees, we have constructed a tree-ring dated chronology from 571 BC to AD 1992. We have also built a 4254-ring floating chronology (placed by radiocarbon at ca. 3580 to 7830 years ago), and an earlier 1268-ring chronology (ca. 7,580 to 8,850 years ago). There are many individuals, or pairs of logs which match and together span several centuries, at 9,000 years ago and beyond

  5. Adiabatic compression of ion rings

    International Nuclear Information System (INIS)

    Larrabee, D.A.; Lovelace, R.V.

    1982-01-01

    A study has been made of the compression of collisionless ion rings in an increasing external magnetic field, B/sub e/ = zB/sub e/(t), by numerically implementing a previously developed kinetic theory of ring compression. The theory is general in that there is no limitation on the ring geometry or the compression ratio, lambdaequivalentB/sub e/ (final)/B/sub e/ (initial)> or =1. However, the motion of a single particle in an equilibrium is assumed to be completely characterized by its energy H and canonical angular momentum P/sub theta/ with the absence of a third constant of the motion. The present computational work assumes that plasma currents are negligible, as is appropriate for a low-temperature collisional plasma. For a variety of initial ring geometries and initial distribution functions (having a single value of P/sub theta/), it is found that the parameters for ''fat'', small aspect ratio rings follow general scaling laws over a large range of compression ratios, 1 3 : The ring radius varies as lambda/sup -1/2/; the average single particle energy as lambda/sup 0.72/; the root mean square energy spread as lambda/sup 1.1/; and the total current as lambda/sup 0.79/. The field reversal parameter is found to saturate at values typically between 2 and 3. For large compression ratios the current density is found to ''hollow out''. This hollowing tends to improve the interchange stability of an embedded low β plasma. The implications of these scaling laws for fusion reactor systems are discussed

  6. Superconducting proton ring for PETRA

    International Nuclear Information System (INIS)

    Baynham, E.

    1979-01-01

    A powerful new facility for colliding beam physics could be provided by adding a proton storage ring in the range of several hundred GeV to the electron-positron storage ring PETRA at DESY. This can be achieved in an economic way utilizing the PETRA tunnel and taking advantage of the higher magnetic fields of superconducting magnets which would be placed above or below the PETRA magnets. A central field of 4 Tesla in the bending magnets corresponds to a proton energy of 225 GeV. (orig.)

  7. The Cryogenic Storage Ring CSR

    OpenAIRE

    von Hahn, Robert; Becker, Arno; Berg, Felix; Blaum, Klaus; Breitenfeldt, Christian; Fadil, Hisham; Fellenberger, Florian; Froese, Michael; George, Sebastian; Göck, Jürgen; Grieser, Manfred; Grussie, Florian; Guerin, Elisabeth A.; Heber, Oded; Herwig, Philipp

    2016-01-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion a...

  8. Supersymmetric rings in field theory

    International Nuclear Information System (INIS)

    Blanco-Pillado, Jose J.; Redi, Michele

    2006-01-01

    We study the dynamics of BPS string-like objects obtained by lifting monopole and dyon solutions of N = 2 Super-Yang-Mills theory to five dimensions. We present exact traveling wave solutions which preserve half of the supersymmetries. Upon compactification this leads to macroscopic BPS rings in four dimensions in field theory. Due to the fact that the strings effectively move in six dimensions the same procedure can also be used to obtain rings in five dimensions by using the hidden dimension

  9. Damping ring designs and issues

    International Nuclear Information System (INIS)

    Wolski, Andrzej; Decking, Winfried

    2003-01-01

    The luminosity performance of a future linear collider (LC) will depend critically on the performance of the damping rings. The design luminosities of the current LC proposals require rings with very short damping times, large acceptance, low equilibrium emittance and high beam intensity. We discuss the design strategies for lattices achieving the goals of dynamical stability, examine the challenges for alignment and coupling correction, and consider a variety of collective effects that threaten to limit beam quality. We put the design goals in context by referring to the experience of operating facilities, and outline the further research and development that is needed

  10. Laparoscopic appendicectomy using endo-ring applicator and fallope rings

    International Nuclear Information System (INIS)

    Ali, Iyoob V; Maliekkal, Joji I

    2009-01-01

    Wider adoption of laparoscopic appendicectomy (LA) is limited by problems in securing the appendiceal base as well as the cost and the duration compared with the open procedure. The objective of this study was to assess the feasibility and efficacy of a new method for securing the appendiceal base in LA, so as to make the entire procedure simpler and cheaper, and hence, more popular. Twenty-five patients who were candidates for appendicectomy (emergency as well as elective) and willing for the laparoscopic procedure were selected for this study. Ports used were 10 mm at the umbilicus, 5 mm at the lower right iliac fossa, and 10 mm at the left iliac fossa. Extremely friable, ruptured, or turgid organs of diameters larger than 8 mm were excluded from the study. The mesoappendix was divided close to the appendix by diathermy. Fallope rings were applied to the appendiceal base using a special ring applicator, and the appendix was divided and extracted through the lumen of the applicator. The procedure was successful in 23 (92%) cases, and the mean duration of the procedure was 20 minutes (15-32 minutes). There were no procedural complications seen during a median follow-up of two weeks. The equipment and rings were cheaper when compared with that of the standard methods of securing the base of the appendix. LA using fallope rings is a safe, simple, easy-to-learn, and economically viable method. (author)

  11. Can restoration convert a degraded bog in southern Bavaria to a carbon sink and climate cooler?

    Science.gov (United States)

    Förster, Christoph; Drösler, Matthias

    2014-05-01

    The peatland area of Germany is about 14.000 km² (Succow & Joosten 2001) with 8% natural like bogs and 4% natural like fens (Höper 2006). All other peatland areas are more or less intensively used and thus, lost their sink function for carbon. If, theoretically, all German peatlands would be rewetted, this restoration would lead to a carbon mitigation of 9.5 Mio. t CO2-C equivalents (Freibauer et al. 2009). In test areas like the studied bog, the viability and potential of peatland restoration for climate mitigation can be proofed. The investigated bog is situated close to the Bavarian Alps; one part of this bog is extensively used and had been rewetted in 1993 except of a small stripe; management was stopped totally at another stripe. The second part of this bog had been drained without any further use. Here a Calluna heath established, accompanied by Pine trees. The restoration of this bog heath was done in two time steps; here a chronosequence of succession after restoration at different water table levels was investigated. To get to the greenhouse gas (GHG) balances of CO2 CH4 and N2O, gas flux measurements were done for two years using the chamber technique of Drösler (2005). At both areas, the degraded sites were sources for GHG (+203 to +736 g CO2-C-equiv m-2 a-1). Restoration reduced these emissions depending on water table and succession of bog species (-51 to +557 g CO2-C-equiv m-2 a-1). Depending on the vegetation's vitality GHG balances of already established natural like sites varied in between the years (-189 to +264 g CO2-C-equiv m-2 a-1) mainly driven by the oscillation of their water table. Stop of management and development of Sphagnum communities turned most of the sites into sinks for GHG (-216 to +7 g CO2-C-equiv m-2 a-1). Thus restoration turned degraded bogs efficiently to carbon sinks and climate coolers in dependence of a proper water table management, withdrawal of land use and vegetation succession. Key words: bog, greenhouse gases

  12. Examination techniques for non-magnetic rings

    International Nuclear Information System (INIS)

    Metala, M.J.; Kilpatrick, N.L.; Frank, W.W.

    1990-01-01

    Until the introduction of 18Mn18Cr rings a few years ago, most non-magnetic steel rings for generator rotors were made from 18Mn5Cr alloy steel, which is highly susceptible to stress corrosion cracking in the presence of water. This, the latest in a series of papers on the subject of non-magnetic rings by the authors' company, provides a discussion of nondestructive examination of 18Mn5Cr rings for stress corrosion distress. With rings on the rotor, fluorescent penetrant, ultrasonic and special visual techniques are applied. With rings off the rotor, the fluorescent penetrant technique is used, with and without stress enhancement

  13. Ring diagrams and phase transitions

    International Nuclear Information System (INIS)

    Takahashi, K.

    1986-01-01

    Ring diagrams at finite temperatures carry most infrared-singular parts among Feynman diagrams. Their effect to effective potentials are in general so significant that one must incorporate them as well as 1-loop diagrams. The author expresses these circumstances in some examples of supercooled phase transitions

  14. WR stars with ring nebulae

    International Nuclear Information System (INIS)

    Tutukov, A.

    1982-01-01

    It is shown that most of usually apparently single nitrogen WR stars with ring emission nebulae around them (WN + Neb) are a probable product of the evolution of a massive close binary with initial masses of components exceeding approximately 20 solar masses. (Auth.)

  15. Alignment for new Subaru ring

    International Nuclear Information System (INIS)

    Zhang, Ch.; Matsui, S.; Hashimoto, S.

    1999-01-01

    The New SUBARU is a synchrotron light source being constructed at the SPring-8 site. The main facility is a 1.5 GeV electron storage ring that provides light beam in the region from VUV to soft X-ray using SPring-8's 1 GeV linac as an injector. The ring, with a circumference of about 119 meters, is composed of six bending cells. Each bending cell has two normal dipoles of 34 degree and one inverse dipole of -8 degree. The ring has six straight sections: two very long straight sections for a 11-m long undulator and an optical klystron, four short straight sections for a 2.3-m undulator, a super-conducting wiggler, rf cavity and injection, etc. The magnets of the storage ring are composed of 12 dipoles (BMs), 6 invert dipoles (BIs), 56 quadrupoles and 44 sextupoles, etc. For the magnet alignment, positions of the dipoles (the BMs and BIs) are determined by network survey method. The multipoles, which are mounted on girders between the dipoles, are aligned with a laser-CCD camera system. This article presents the methodology used to position the different components and particularly to assure the precise alignment of the multipoles. (authors)

  16. Characteristic of Rings. Prime Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-12-01

    Full Text Available The notion of the characteristic of rings and its basic properties are formalized [14], [39], [20]. Classification of prime fields in terms of isomorphisms with appropriate fields (ℚ or ℤ/p are presented. To facilitate reasonings within the field of rational numbers, values of numerators and denominators of basic operations over rationals are computed.

  17. Ring laser frequency biasing mechanism

    International Nuclear Information System (INIS)

    McClure, R.E.

    1975-01-01

    A ring laser cavity including a magnetically saturable member for differentially phase shifting the contradirectional waves propagating in the laser cavity, the phase shift being produced by the magneto-optic interaction occurring between the light waves and the magnetization in the cavity forming component as the light waves are reflected therefrom is described

  18. Counting problems for number rings

    NARCIS (Netherlands)

    Brakenhoff, Johannes Franciscus

    2009-01-01

    In this thesis we look at three counting problems connected to orders in number fields. First we study the probability that for a random polynomial f in Z[X] the ring Z[X]/f is the maximal order in Q[X]/f. Connected to this is the probability that a random polynomial has a squarefree

  19. Progressiv læring

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    2017-01-01

    SAMMENFATNING I denne evalueringsrapport præsenterer Nationalt Center for Kompetenceudvikling ved Aarhus Universitet (herefter NCK) og Rambøll Management Consulting (herefter Rambøll) den værktøjsspecifikke evaluering af Progressiv Læring som pædagogisk værktøj for de ni implementeringsskoler i s...

  20. Wands of the Black Ring

    Czech Academy of Sciences Publication Activity Database

    Pravda, Vojtěch; Pravdová, Alena

    2005-01-01

    Roč. 37, č. 7 (2005), s. 1277-1287 ISSN 0001-7701 R&D Projects: GA ČR GP202/03/P017; GA AV ČR KJB1019403 Institutional research plan: CEZ:AV0Z10190503 Keywords : algebraic classification * Petrov classification * black ring Subject RIV: BA - General Mathematics Impact factor: 1.550, year: 2005

  1. Substitution of matrices over rings

    NARCIS (Netherlands)

    Hautus, M.L.J.

    1995-01-01

    For a given commutative ring with an identity element, we define and study the substitution of a matrix with entries in into a matrix polynomial or rational function over . A Bezout-type remainder theorem and a "partial-substitution rule" are derived and used to obtain a number of results. The

  2. Exercises in modules and rings

    CERN Document Server

    Lam, TY

    2009-01-01

    This volume offers a compendium of exercises of varying degree of difficulty in the theory of modules and rings. All exercises are solved in full detail. Each section begins with an introduction giving the general background and the theoretical basis for the problems that follow.

  3. On commutativity theorems for rings

    Directory of Open Access Journals (Sweden)

    H. A. S. Abujabal

    1990-01-01

    Full Text Available Let R be an associative ring with unity. It is proved that if R satisfies the polynomial identity [xny−ymxn,x]=0(m>1,n≥1, then R is commutative. Two or more related results are also obtained.

  4. Numerical investigation of wet-bulb effectiveness and water consumption in one-and two-stage indirect evaporative coolers

    International Nuclear Information System (INIS)

    Moshari, Shahab; Heidarinejad, Ghassem; Fathipour, Aida

    2016-01-01

    Highlights: • Wet bulb effectiveness of indirect/indirect evaporative cooling systems are 76–81%. • Dimensionless water evaporation rate decreases as the primary air flow rate increases. • Water evaporation rate increases with increase of inlet dry bulb temperature. - Abstract: In this study, three configuration for two-stage indirect/indirect evaporative cooling systems (IEC/IEC) were proposed (Type A, Type B and Type C) to determine what configuration produces a better wet-bulb effectiveness (or better energy-saving). For this purpose, six cities with a variety of hot weather conditions with the dry-bulb in range of 31.9–46.66 °C were selected. Results show that under these three configuration, the wet-bulb effectiveness of Type A, Type B and Type C varies over ranges of 62–68%, 76–81% and 85–91% respectively, whereas the effectiveness of a one stage IEC varies over a range of 54–60%. There is a common misconceive belief in the concept of water evaporation rate of an evaporative cooling system, which were fueled by many articles; this belief is, if a cooler consumes less water it is an environmentally friendly cooler for dry areas. A more accurate and practical definition is proposed in this article named Dimensionless Water Evaporation Rate (DWER). The numerical results showed that Type B is the optimum configuration, because of a range of 4–24% DWER saving could be obtained by Type B in comparison with Type C whereas Type B increases the product air up to 32%. As well as IEC, in a counter-flow regenerative evaporative cooler the DWER decreases as the primary airflow rate increases whereas water consumption increases. Moreover, using Type B the index of thermal comfort was investigated which showed that Type B could meet thermal comfort condition in two climatic zones of temperate-dry and hot-dry.

  5. Experimental study on the thermal management of high-power LED headlight cooling device integrated with thermoelectric cooler package

    International Nuclear Information System (INIS)

    Wang, Jing; Zhao, Xin-Jie; Cai, Yi-Xi; Zhang, Chun; Bao, Wei-Wei

    2015-01-01

    Highlights: • A novel TEC cooling system for multi-chip LED module was successfully developed. • Influences of liquid velocity on the system thermal performance were investigated. • TEC system is more sensitive to the input current than that of the mere air cooling. • The junction temperature can be maintained below 61.8 °C (liquid cooling & TEC). - Abstract: In view of the characteristics of high power light-emitting diodes (LEDs), such as strict junction temperature (T j ) control, the enhanced cooling models based on the thermoelectric cooler (TEC) were presented to meet the thermal demand of high-power LED headlight. The cooling performance of different devices (air cooling & TEC, liquid cooling & TEC) was evaluated and compared by measuring the LED case temperature. Details of the heat transfer performance, particularly, the start-up performances of the TEC cooler, as well as the influence of the fan rotate speed or liquid velocity on the system thermal performance were obtained. It was found that the thermal performance had been elevated dramatically due to the reduction of the hot side temperature, and the thermoelectric cooler was more sensitive to the external fan speed or liquid velocity than purely air cooling or liquid cooling. In addition, the optimal current for air cooling & TEC was 3A, and 5A for liquid cooling + TEC. Investigations of the simulated ambient temperature on junction temperature, forward voltage, and output light were conducted. Results indicated that the case temperature changed linear basically with the increase in heating power or the simulated ambient temperature. When the ambient temperature was within its severe level (60–65 °C), the junction temperature could be calculated to 59.5 °C, and the corresponding output light was 1607.3 lm

  6. Multi-objective optimization design of air distribution of grate cooler by entropy generation minimization and genetic algorithm

    International Nuclear Information System (INIS)

    Shao, Wei; Cui, Zheng; Cheng, Lin

    2016-01-01

    Highlights: • A multi-objective optimization model of air distribution of grate cooler by genetic algorithm is proposed. • Pareto Front is obtained and validated by comparing with operating data. • Optimal schemes are compared and selected by engineering background. • Total power consumption after optimization decreases 61.10%. • Thickness of clinker on three grate plates is thinner. - Abstract: The cooling air distributions of grate cooler exercise a great influence on the clinker cooling efficiency and power consumption of cooling fans. A multi-objective optimization model of air distributions of grate cooler with cross-flow heat exchanger analogy is proposed in this paper. Firstly, thermodynamic and flow models of clinker cooling process is carried out. Then based on entropy generation minimization analysis, modified entropy generation numbers caused by heat transfer and pressure drop are chosen as objective functions respectively which optimized by genetic algorithm. The design variables are superficial velocities of air chambers and thicknesses of clinker layers on different grate plates. A set of Pareto optimal solutions which two objectives are optimized simultaneously is achieved. Scattered distributions of design variables resulting in the conflict between two objectives are brought out. The final optimal air distribution and thicknesses of clinker layers are selected from the Pareto optimal solutions based on power consumption of cooling fans minimization and validated by measurements. Compared with actual operating scheme, the total air volumes of optimized schemes decrease 2.4%, total power consumption of cooling fans decreases 61.1% and the outlet temperature of clinker decreases 122.9 °C which shows a remarkable energy-saving effect on energy consumption.

  7. A techno-economic analysis of cost savings for retrofitting industrial aerial coolers with variable frequency drives

    International Nuclear Information System (INIS)

    Miller, Patrick; Olateju, Babatunde; Kumar, Amit

    2012-01-01

    Highlights: ► Techno-economic models were developed to assess the retrofitting of aerial coolers. ► The IRR for retrofitting with VFDs exceeds 10% for motor sizes above 20 hp. ► The IRR reaches a maximum of 220% for a cooler with fifty, 250 hp motors. ► The simple payback becomes less than 1 year for motors larger than 120 hp. ► Ambient temperature and location affects the profitability of VFD investment. - Abstract: A techno-economic model was created in order to develop curves that show the typical annual energy savings, rate of return, and payback for retrofitting aerial coolers with variable frequency drives (VFDs) for up to 50 motors, motor sizes from 4 to 186 kW (5–250 hp), and varying climate conditions. The cost savings due to installing a VFD depends on the reduction in energy used, as well as the reduction in power demand, the capital cost of the VFD, installation cost of the VFD, change in operating cost, and cost of electricity. The geographic locations examined in this report were Fort McMurray, Calgary, Vancouver, and Thunder Bay. This study found that the IRR increases rapidly with motor size, becomes greater than 10% at a motor size of approximately 15 kW, and may be as high as 220% (for the case of fifty, 186 kW motors). The IRR is sensitive to the number of fan motors retrofitted with VFDs, however the sensitivity rapidly declines as the number of motors is increased beyond five. The simple payback period becomes less than 1 year and nearly independent of number of motors and motor size for motors larger than 90 kW. Ambient temperature and geographic location affect the profitability of the investment, although the IRR only changes by approximately 4%.

  8. A comparative study on energetic, exergetic and environmental performance assessments of novel M-Cycle based air coolers for buildings

    International Nuclear Information System (INIS)

    Caliskan, Hakan; Dincer, Ibrahim; Hepbasli, Arif

    2012-01-01

    Highlights: ► Applying exergy, environment and sustainability analyses to the three (novel M-Cycle based) air coolers. ► Assessing energy and exergy efficiencies, environmental impact and sustainability. ► Proposing System II (using PV-based electricity) as the most environmentally friendly air cooler. ► Proposing System III (using coal-based electricity) as the most efficient air cooler. - Abstract: In this study, three various novel air coolers based on M-Cycle are evaluated using energy and exergy analyses based efficiency assessments along with environmental impact and sustainability parameters. The M-Cycle systems are considered to cool a building room air while their inlet air parameters are same, but outlet cooled air parameters are different. Systems I and III draw electricity directly taken from an electric grid in the building while System II, which is stand alone system, produces and draws electricity from its solar PV panels. In the energy analysis, wet bulb effectiveness, cooling capacity, Coefficient of Performance (energetic COP) and Primary Energy Ratio (PER) are found. In the exergy analysis, exergy input and output rates, exergy loss rate, exergy destruction rate, Exergetic Coefficient of Performance (COP ex ), Primary Exergy Ratio (PE x R) and exergy efficiency are obtained for six different dead state temperatures changing between 10 °C and 35 °C. Also, sustainability assessments of the systems are obtained using sustainability index (SI) tool for these various dead state temperatures. Finally, environmental assessments of the systems are calculated from their greenhouse gas (GHG) emissions (gCO 2 /kW h) due to their electricity consumptions. Maximum exergy efficiencies and sustainability assessments are found to be 35.13% and 1.5415 for System III and 34.94% and 1.5372 for System II, respectively. GHG emissions of the systems are calculated to be 2119.68 gCO 2 /day, 153.6 gCO 2 /day and 3840 gCO 2 /day for Systems I, II and III

  9. Changes of reproductive system of pike Esox Lucius L. in lake Drukshiai -the cooler of Ignalina NPP

    International Nuclear Information System (INIS)

    Lukshiene, D.

    1995-01-01

    On studying the reproductive system of pike in lake Drukshiai during 1992-1994 the same changes in fish gameto- and gonadogenesis as in other coolers were observed: -intensification of gametogenesis processes - earlier sexual maturity; -changes in gonadogenesis processes - a bias of all stages of sexual cycle as well as a change in duration; -disturbance of gametogenesis processes - total and partial degeneration of oocytes causing the disturbance of reproduction cycle what is reflected in the changes of some biological indices (gonadosomatic index and oocyte diameter). The above mentioned disturbances have a negative effect on normal functioning and reproduction of a pike population. (author). 8 refs., 2 figs

  10. HISTRAP [Heavy Ion Storage Ring for Atomic Physics] vacuum test stand for pressures of 10-12 Torr

    International Nuclear Information System (INIS)

    Johnson, J.W.; Atkins, W.H.; Dowling, D.T.; McConnell, J.W.; Milner, W.T.; Olsen, D.K.

    1988-01-01

    HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed synchrotron/cooler/storage ring accelerator optimized for advanced atomic physics research. The ring has a circumference of 46.8 m, a bore diameter of about 15 cm, and requires a vacuum of 10 -12 Torr in order to decelerate highly-charged very-heavy ions down to low energies. To be able to test components and procedures to achieve this pressure, a test stand approximately modeling one-sixteenth of the ring vacuum chamber has been built. The 3.5-m-long test stand has been fabricated from 10-cm-diameter components, with 316LN stainless steel flanges. Prior to assembly, these components were vacuum fired at 950/degree/C at a pressure of 10 -4 Torr. The test stand is bakeable in situ at 300/degree/C. Pumping is achieved with two 750-L/s titanium sublimator pumps and one 60-L/s ion pump. Pressure is measured with two extractor ion gauges and a 10 -14 PP RGA. The roughing for the test stand consists of cryosorption pumps followed by a cryopump. A pressure of 4 x 10 -12 Torr has been achieved. 7 refs., 5 figs

  11. 21 CFR 870.3800 - Annuloplasty ring.

    Science.gov (United States)

    2010-04-01

    ...) Identification. An annuloplasty ring is a rigid or flexible ring implanted around the mitral or tricuspid heart valve for reconstructive treatment of valvular insufficiency. (b) Classification. Class II (special...

  12. International Tree Ring Data Bank (ITRDB)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives. Data include raw treering measurements (most are...

  13. Planetary ring systems properties, structures, and evolution

    CERN Document Server

    Murray, Carl D

    2018-01-01

    Planetary rings are among the most intriguing structures of our solar system and have fascinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring–particle orbits is followed by a review of the known planetary ring systems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties and their origins, and investigations using computer simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field's future. Researchers of all levels will benefit from this thorough and engaging presentation.

  14. Vortex rings in classical and quantum systems

    International Nuclear Information System (INIS)

    Barenghi, C F; Donnelly, R J

    2009-01-01

    The study of vortex rings has been pursued for decades and is a particularly difficult subject. However, the discovery of quantized vortex rings in superfluid helium has greatly increased interest in vortex rings with very thin cores. While rapid progress has been made in the simulation of quantized vortex rings, there has not been comparable progress in laboratory studies of vortex rings in a viscous fluid such as water. This article overviews the history and current frontiers of classical and quantum vortex rings. After introducing the classical results, this review discusses thin-cored vortex rings in superfluid helium in section 2, and recent progress in understanding vortex rings of very thin cores propagating in water in section 3. (invited paper)

  15. Mathematical simulation of bearing ring grinding process

    Science.gov (United States)

    Koltunov, I. I.; Gorbunova, T. N.; Tumanova, M. B.

    2018-03-01

    The paper suggests the method of forming a solid finite element model of the bearing ring. Implementation of the model allowed one to evaluate the influence of the inner cylindrical surface grinding scheme on the ring shape error.

  16. Dynamics of long ring Raman fiber laser

    Science.gov (United States)

    Sukhanov, Sergey V.; Melnikov, Leonid A.; Mazhirina, Yulia A.

    2016-04-01

    The numerical model for dynamics of long fiber ring Raman laser is proposed. The model is based on the transport equations and Courant-Isaacson-Rees numerical method. Different regimes of a long ring fiber Raman laser are investigated.

  17. Genetics Home Reference: ring chromosome 20 syndrome

    Science.gov (United States)

    ... drugs. Prolonged seizure episodes known as non-convulsive status epilepticus also appear to be characteristic of ring chromosome ... K, Takahashi Y. Ring chromosome 20 and nonconvulsive status epilepticus. A new epileptic syndrome. Brain. 1997 Jun;120 ( ...

  18. Containment fan cooler heat transfer calculation during main steam line break for Maanshan PWR plant

    Energy Technology Data Exchange (ETDEWEB)

    Yuann, Yng-Ruey, E-mail: ryyuann@iner.gov.tw; Kao, Lain-Su, E-mail: lskao@iner.gov.tw

    2013-10-15

    Highlights: • Evaluate component cooling water (CCW) thermal response during MSLB for Maanshan. • Using GOTHIC to calculate CCW temperature and determine time required to boil CCW. • Both convective and condensation heat transfer from the air side are considered. • Boiling will not occur since T{sub B} is sufficiently longer than CCW pump restart time. -- Abstract: A thermal analysis has been performed for the Containment Fan Cooler Unit (FCU) during Main Steam Line Break (MSLB) accident, concurrent with loss of offsite power, for Maanshan PWR plant. The analysis is performed in order to address the waterhammer and two-phase flow issues discussed in USNRC's Generic Letter 96-06 (GL 96-06). Maanshan plant is a twin-unit Westinghouse 3-loop PWR currently operated at rated core thermal power of 2822 MWt for each unit. The design basis for containment temperature is Main Steam Line Break (MSLB) accident at power of 2830.5 MWt, which results in peak vapor temperature of 387.6 °F. The design is such that when MSLB occurs concurrent with loss of offsite power (MSLB/LOOP), both the coolant pump on the secondary side and the fan on the air side of the FCU loose power and coast down. The pump has little inertia and coasts down in 2–3 s, while the FCU fan coasts down over much longer period. Before the pump is restored through emergency diesel generator, there is potential for boiling the coolant in the cooling coils by the high-temperature air/steam mixture entering the FCU. The time to boiling depends on the operating pressure of the coolant before the pump is restored. The prediction of the time to boiling is important because it determines whether there is potential for waterhammer or two-phase flow to occur before the pump is restored. If boiling occurs then there exists steam region in the pipe, which may cause the so called condensation induced waterhammer or column closure waterhammer. In either case, a great amount of effort has to be spent to

  19. The Hi-Ring DCN Architecture

    DEFF Research Database (Denmark)

    Galili, Michael; Kamchevska, Valerija; Ding, Yunhong

    2016-01-01

    We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization......We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization...

  20. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  1. On P-coherent endomorphism rings

    Indian Academy of Sciences (India)

    A ring is called right -coherent if every principal right ideal is finitely presented. Let M R be a right -module. We study the -coherence of the endomorphism ring of M R . It is shown that is a right -coherent ring if and only if every endomorphism of M R has a pseudokernel in add M R ; S is a left -coherent ring if and ...

  2. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing; Arcak, Murat; Salama, Khaled N.

    2010-01-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  3. Beam dynamic issues in TESLA damping ring

    International Nuclear Information System (INIS)

    Shiltsev, V.

    1996-05-01

    In this paper we study general requirements on impedances of the linear collider TESLA damping ring design. Quantitative consideration is performed for 17-km long ''dog-bone'' ring. Beam dynamics in alternative options of 6.3 and 2.3-km long damping rings is briefly discussed. 5 refs., 2 tabs

  4. IAG ring test animal proteins 2014

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinckaers, V.G.Z.; Scholtens-Toma, I.M.J.; Prins, T.W.; Voet, van der H.; Vliege, J.J.M.

    2014-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG – International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The aim of the ring study was to provide the participants

  5. IAG ring test animal proteins 2015

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Rhee, van de N.E.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.; Pinckaers, V.G.Z.

    2015-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the ring test was RIKILT - Wageningen UR, The

  6. IAG ring test animal proteins 2013

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinckaers, V.G.Z.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.

    2013-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the the ring study was to provide the

  7. Self-gravitation in Saturn's rings

    International Nuclear Information System (INIS)

    Salo, H.; Lukkari, J.

    1982-01-01

    In a ring-shaped collisional system self-gravitation reduces the equilibrium values of the geometric and optical thickness. In Saturn's rings both effects are appreciable. The previously found discrepancy between the calculated profile and the observed profile of the rings is chiefly caused by the omission of self-gravitation. (Auth.)

  8. Efficient on-chip hotspot removal combined solution of thermoelectric cooler and mini-channel heat sink

    International Nuclear Information System (INIS)

    Hao, Xiaohong; Peng, Bei; Xie, Gongnan; Chen, Yi

    2016-01-01

    Highlights: • A combined solution of thermoelectric cooler (TEC) and mini-channel heat sink to remove the hotspot of the chip has been proposed. • The TEC's mathematical model is established to assess its work performance. • A comparative study on the proposed efficient On-Chip Hotspot Removal Combined Solution. - Abstract: Hotspot will significantly degrade the reliability and performance of the electronic equipment. The efficient removal of hotspot can make the temperature distribution uniform, and ensure the reliable operation of the electronic equipment. This study proposes a combined solution of thermoelectric cooler (TEC) and mini-channel heat sink to remove the hotspot of the chip in the electronic equipment. Firstly, The TEC's mathematical model is established to assess its work performance under different boundary conditions. Then, the hotspot removal capability of the TEC is discussed for different cooling conditions, which has shown that the combined equipment has better hotspot removal capability compared with others. Finally, A TEC is employed to investigate the hotspot removal capacity of the combined solution, and the results have indicated that it can effectively remove hotspot in the diameter of 0.5 mm, the power density of 600W/cm 2 when its working current is 3A and heat transfer thermal resistance is 0 K/W.

  9. Numerical study on the performance of vacuum cooler and evaporation-boiling phenomena during vacuum cooling of cooked meat

    International Nuclear Information System (INIS)

    Jin, T.X.; Xu, L.

    2006-01-01

    The vacuum cooling of cooked meats is described in this paper. Based on the energy and mass balance, a modified mathematical model based on a previous model is developed to analyze the performance of the vacuum cooler and the evaporation-boiling phenomena during vacuum cooling of cooked meat. Validation experimentation is performed in the designed vacuum cooler. Boiling occurs inside the cooked meat. There is a boiling front, and the boiling front moves toward the center of the cooked meat as the vacuum cooling proceeds. The experimental data are compared with the simulation results. It is found that the differences of the temperature between the simulation and the experimentation are within 5 deg. C, and the deviation of weight loss between the simulation and the experimentation is within 4%. The simulation results agree with the experimental data well. The modified model can be used to predict the variation of the vacuum pressure in the chamber, the temperature and pressure distributions and the weight loss profiles of cylindrical cooked meats

  10. Fourth-generation storage rings

    International Nuclear Information System (INIS)

    Galayda, J. N.

    1999-01-01

    It seems clear that a linac-driven free-electron laser is the accepted prototype of a fourth-generation facility. This raises two questions: can a storage ring-based light source join the fourth generation? Has the storage ring evolved to its highest level of performance as a synchrotrons light source? The answer to the second question is clearly no. The author thinks the answer to the first question is unimportant. While the concept of generations has been useful in motivating thought and effort towards new light source concepts, the variety of light sources and their performance characteristics can no longer be usefully summed up by assignment of a ''generation'' number

  11. Development of the performance of an alpha-type heat engine by using elbow-bend transposed-fluids heat exchanger as a heater and a cooler

    Energy Technology Data Exchange (ETDEWEB)

    El-Ehwany, A.A.; Hennes, G.M. [Mechanical Power Department, Faculty of Engineering, Ain Shams University, 11566 Cairo (Egypt); Eid, E.I. [Mechanical Department, Faculty of Industrial Education, Suez Canal University, 43515 Suez (Egypt); El-Kenany, E.A. [Technological Development Department, Technological Studies Academy, Workers University, Tanta (Egypt)

    2011-02-15

    In this work, elbow-bend heat exchangers were suggested to be used as a heater and a cooler in an alpha-type Stirling engine. Elbow-bend heat exchanger is a bank of tubes arranged in a quadrant either in line or staggered with different normal and parallel pitches. Eight of such heat exchangers having different dimensions were tested experimentally for steady flow (in a previous work by the same authors). The experimental results were correlated for heat transfer and pressure drop. In the present work, an alpha-Stirling engine with twin parallel cylinders on a common crankcase was suggested to use elbow-bend heat exchangers as a heater and a cooler. In the heater, the flue gases flow inside the tubes and the working gas fluctuates about the heater tubes. In the cooler, the coolant flows inside the cooler tubes and the gas flows about the cooler tubes. A computer program in the form of a spread sheet was prepared to solve numerically the engine cycle in the vision of Schmidt theory. Upon calculations, the most suitable stroke/bore ratio, phase angle and speed were found out for nitrogen as a working gas. In a comparison among the proposed engine and practical ones by the literature, it was found that; the proposed engine delivers about 13% more power per cc per {delta}T than those by the literature at high thermal efficiency level. (author)

  12. Effect of cooler electrons on a compressive ion acoustic solitary wave in a warm ion plasma — Forbidden regions, double layers, and supersolitons

    International Nuclear Information System (INIS)

    Ghosh, S. S.; Sekar Iyengar, A. N.

    2014-01-01

    It is observed that the presence of a minority component of cooler electrons in a three component plasma plays a deterministic role in the evolution of solitary waves, double layers, or the newly discovered structures called supersolitons. The inclusion of the cooler component of electrons in a single electron plasma produces sharp increase in nonlinearity in spite of a decrease in the overall energy of the system. The effect maximizes at certain critical value of the number density of the cooler component (typically 15%–20%) giving rise to a hump in the amplitude variation profile. For larger amplitudes, the hump leads to a forbidden region in the ambient cooler electron concentration which dissociates the overall existence domain of solitary wave solutions in two distinct parameter regime. It is observed that an inclusion of the cooler component of electrons as low as < 1% affects the plasma system significantly resulting in compressive double layers. The solution is further affected by the cold to hot electron temperature ratio. In an adequately hotter bulk plasma (i.e., moderately low cold to hot electron temperature ratio), the parameter domain of compressive double layers is bounded by a sharp discontinuity in the corresponding amplitude variation profile which may lead to supersolitons

  13. Effect of cooler electrons on a compressive ion acoustic solitary wave in a warm ion plasma — Forbidden regions, double layers, and supersolitons

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S. S., E-mail: sukti@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410218 (India); Sekar Iyengar, A. N. [Plasma Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India)

    2014-08-15

    It is observed that the presence of a minority component of cooler electrons in a three component plasma plays a deterministic role in the evolution of solitary waves, double layers, or the newly discovered structures called supersolitons. The inclusion of the cooler component of electrons in a single electron plasma produces sharp increase in nonlinearity in spite of a decrease in the overall energy of the system. The effect maximizes at certain critical value of the number density of the cooler component (typically 15%–20%) giving rise to a hump in the amplitude variation profile. For larger amplitudes, the hump leads to a forbidden region in the ambient cooler electron concentration which dissociates the overall existence domain of solitary wave solutions in two distinct parameter regime. It is observed that an inclusion of the cooler component of electrons as low as < 1% affects the plasma system significantly resulting in compressive double layers. The solution is further affected by the cold to hot electron temperature ratio. In an adequately hotter bulk plasma (i.e., moderately low cold to hot electron temperature ratio), the parameter domain of compressive double layers is bounded by a sharp discontinuity in the corresponding amplitude variation profile which may lead to supersolitons.

  14. ring mellem elever

    DEFF Research Database (Denmark)

    Davidsen, Jacob; Georgsen, Marianne

    I denne rapport tilbyder vi et indblik i det gennemførte projekt, og forfatterne har valgt nogle forhold ud, som belyses og diskuteres, mens andre ikke berøres eller diskuteres nævneværdigt i denne rapport. Det skyldes blandt andet projektets mange facetter, som dækker både læring, teknologi, pæd...

  15. ring mellem elever

    DEFF Research Database (Denmark)

    Georgsen, Marianne; Davidsen, Jacob

    2010-01-01

    I denne rapport præsenteres resultater fra følgeforskningen til projektet Læring gennem Bevægelse, som er gennemført på Søndervangskolen i Hammel i perioden august 2009 - maj 2010. Projektet er gennemført i samspil mellem lærere, it-vejleder, elever og skolens ledelse. Projektets overordnede formål...

  16. Two superconducting storage rings: ISABELLE

    International Nuclear Information System (INIS)

    Sanford, J.R.

    1978-01-01

    The general features of the design and the status of the ISABELLE storage ring project at the present time are reported. It brings up to date the results reported at the National Particle Accelerator Conference in March 1977. The most significant change since that time has been an upgrading of the energy of the overall facility, and acceptance of the project by the Department of Energy

  17. ring og it

    DEFF Research Database (Denmark)

      Antologien er et bidrag til didaktiske diskussioner om brug af f.eks. programpakker til sprogundervisning, præsentationsprogrammel og konferencesystemer på de videregående uddannelser. Antologien diskuterer ideen om, at multimediale medier og internettet kan understøtte læring, undervisning og ...... samarbejde ud fra konkrete eksempler på it-anvendelser, hvor fokus er på potentialer, barrierer og faldgruber....

  18. Carbon-14 in tree rings

    International Nuclear Information System (INIS)

    Cain, W.F.; Suess, H.E.

    1976-01-01

    In order to investigate how reliably the carbon 14 content of tree rings reflects that of atmospheric carbon dioxide, two types of determinations were carried out: (1) carbon 14 determinations in annual rings from the beginning of this century until 1974 and (2) carbon 14 determinations in synchronous wood from the North American bristlecone pine and from European oak trees, dendrochronologically dated to have grown in the third and fourth century B.C. The first series of measurements showed that bomb-produced radiocarbon was incorporated in wood at a time when it was converted from sapwood to heartwood, whenever radiocarbon from bomb testing was present in the atmosphere. The second series showed that wood more than 2000 years old and grown on two different continents at different altitudes had, within the limits of experimental error, the same radiocarbon content. This work and other experimental evidence, obtained in part by other laboratories, show that tree rings reflect the average radiocarbon content of global atmospheric carbon dioxide accurately within several parts per mil. In rare cases, deviations of up to 10 parts per thousand may be possible. This means that a typical single radiocarbon date for wood or charcoal possesses an intrinsic uncertainty (viz., an estimated ''one-sigma error'' in addition to all the other errors) of the order of +-50 years. This intrinsic uncertainty is independent of the absolute age of the sample. More accurate dates can, in principle, be obtained by the so-called method of ''wiggle matching.''

  19. Ring enhancement in recurrent gliomas

    International Nuclear Information System (INIS)

    Ogashiwa, Motohide; Takeuchi, Kazuo; Akai, Keiichiro

    1981-01-01

    The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas. (author)

  20. Ring enhancement in recurrent gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Ogashiwa, M; Takeuchi, K; Akai, K [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    1981-08-01

    The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas.

  1. Evidence for Quantisation in Planetary Ring Systems

    OpenAIRE

    WAYTE, RICHARD

    2017-01-01

    Absolute radial positions of the main features in Saturn's ring system have been calculated by adapting the quantum theory of atomic spectra. Fine rings superimposed upon broad rings are found to be covered by a harmonic series of the form N α A(r)1/2, where N and A are integers. Fourier analysis of the ring system shows that the spectral amplitude fits a response profile which is characteristic of a resonant system. Rings of Jupiter, Uranus and Neptune also obey the same rules. Involvement o...

  2. Vaginal rings for delivery of HIV microbicides.

    Science.gov (United States)

    Malcolm, R Karl; Fetherston, Susan M; McCoy, Clare F; Boyd, Peter; Major, Ian

    2012-01-01

    Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing.

  3. Leapfrogging of multiple coaxial viscous vortex rings

    International Nuclear Information System (INIS)

    Cheng, M.; Lou, J.; Lim, T. T.

    2015-01-01

    A recent theoretical study [Borisov, Kilin, and Mamaev, “The dynamics of vortex rings: Leapfrogging, choreographies and the stability problem,” Regular Chaotic Dyn. 18, 33 (2013); Borisov et al., “The dynamics of vortex rings: Leapfrogging in an ideal and viscous fluid,” Fluid Dyn. Res. 46, 031415 (2014)] shows that when three coaxial vortex rings travel in the same direction in an incompressible ideal fluid, each of the vortex rings alternately slips through (or leapfrogs) the other two ahead. Here, we use a lattice Boltzmann method to simulate viscous vortex rings with an identical initial circulation, radius, and separation distance with the aim of studying how viscous effect influences the outcomes of the leapfrogging process. For the case of two identical vortex rings, our computation shows that leapfrogging can be achieved only under certain favorable conditions, which depend on Reynolds number, vortex core size, and initial separation distance between the two rings. For the case of three coaxial vortex rings, the result differs from the inviscid model and shows that the second vortex ring always slips through the leading ring first, followed by the third ring slipping through the other two ahead. A simple physical model is proposed to explain the observed behavior

  4. Plasma-ring, fast-opening switch

    International Nuclear Information System (INIS)

    Hartman, C.W.; Eddleman, J.; Hammer, J.H.

    1986-01-01

    The authors discuss a fast-opening switch concept based on magnetically confined plasma rings, PROS (for Plasma Ring Opening Switch). In PROS, the plasma ring, confined by Bθ /sub and B/poloidal /sub fields of a compact torus, provide a low mass, localized conduction path between coaxial electrodes. To operate the switch, driver current is passed across the electrodes through the ring, storing inductive energy in external inductance and between the electrodes on the driver side of the ring. The ring is accelerated away from the driver by the field of the driver current and passes over a load gap transferring the current to the load. The authors distinguish two configurations in PROS, straight PROS where the electrodes are coaxial cylinders, and cone PROS with conical electrodes. In straight PROS ring acceleration takes place during the inductive store period as in foil switches, but with the localized ring providing the current path. Increased performance is predicted for the cone PROS (see figure) which employs compression of the ring in the cone during the inductive store period. Here, the B/θ /sub field of the driver forces the ring towards the apex of the cone but the force is in near balance with the opposing component of the radial equilibrium force of the ring along the cone. As a result, the ring undergoes a slow, quasistatic compression limited only by resistive decay of the ring field. Slow compression allows inductive storage with low-power drivers (homopoloar, magneto cumulative generators, high C-low V capacitor banks, etc.). Near the apex of the cone, near peak compression, the ring is allowed to enter a straight coaxial section where, because of low-mass, it rapidly accelerates to high velocity and crosses the load gap

  5. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

    Science.gov (United States)

    Johnston, James D; Tuttle, Steven C; Nelson, Morgan C; Bradshaw, Rebecca K; Hoybjerg, Taylor G; Johnson, Julene B; Kruman, Bryce A; Orton, Taylor S; Cook, Ryan B; Eggett, Dennis L; Weber, K Scott

    2016-01-01

    Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr) and summer (July-Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.

  6. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

    Directory of Open Access Journals (Sweden)

    James D Johnston

    Full Text Available Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr and summer (July-Sept, 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.

  7. Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    Science.gov (United States)

    Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

    2010-12-01

    Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  8. Einstein Ring in Distant Universe

    Science.gov (United States)

    2005-06-01

    Using ESO's Very Large Telescope, Rémi Cabanac and his European colleagues have discovered an amazing cosmic mirage, known to scientists as an Einstein Ring. This cosmic mirage, dubbed FOR J0332-3557, is seen towards the southern constellation Fornax (the Furnace), and is remarkable on at least two counts. First, it is a bright, almost complete Einstein ring. Second, it is the farthest ever found. ESO PR Photo 20a/05 ESO PR Photo 20a/05 Deep Image of a Region in Fornax (FORS/VLT) [Preview - JPEG: 400 x 434 pix - 60k] [Normal - JPEG: 800 x 867 pix - 276k] [Full Res - JPEG: 1859 x 2015 pix - 3.8M] ESO PR Photo 20b/05 ESO PR Photo 20b/05 Zoom-in on the Newly Found Einstein Ring (FORS/VLT) [Preview - JPEG: 400 x 575 pix - 168k] [Normal - JPEG: 630 x 906 pix - 880k] Caption: ESO PR Photo 20a/05 is a composite image taken in two bands (B and R) with VLT/FORS1 of a small portion of the sky (field-of-view 7x7' or 1/15th of the area of the full moon). The faintest object seen in the image has a magnitude 26, that is, it is 100 million times fainter than what can be observed with the unaided eye. The bright elliptical galaxy on the lower-left quadrant is a dwarf galaxy part of a large nearby cluster in the Fornax constellation. As for all deep images of the sky, this field shows a variety of objects, the brightest ponctual sources being stars from our Galaxy. By far the field is dominated by thousands of faint background galaxies the colours of which are related to the age of their dominant stellar population, their dust content and their distance. The newly found Einstein ring is visible in the top right part of the image. ESO PR Photo 20b/05 zooms-in on the position of the newly found cosmic mirage. ESO PR Photo 20c/05 ESO PR Photo 20c/05 Einstein Ring in Distant Universe (FORS/VLT) [Preview - JPEG: 400 x 584 pix - 104k] [Normal - JPEG: 800 x 1168 pix - 292k] [Full Res - JPEG: 1502 x 2192 pix - 684k] Caption of ESO PR Photo 20c/05: The left image is magnified and centred

  9. Experiments with highly-charged heavy-ions performed at the storage ring ESR

    International Nuclear Information System (INIS)

    Mokler, P.H.

    1992-01-01

    The new heavy ion accelerator facility SIS/ESR was inaugurated in April 1990. During 1991 the experimental storage ring, ESR, has been commissioned. Highly-charged heavy ions from O 8+ up to Bi 82+ were successfully accumulated, cooled, and stored in the ring. Now all highly-charged, heavy ions can be provided for experiments at comfortable storage times and at energies roughly between 100 and 500 MeV/u. A report on the achievements and on the first experimental results will be given. For the experiments, special emphasis is put on capture processes in the electron cooler, i.e. on radiative and dielectronic recombination processes as well as on capture events of bound target electrons from a gas jet. In this case, the capture leads either directly (REC) or by cascading to X-ray emission, which is also exploited for a precision spectroscopy of the structure of the heaviest ions. Another exciting topic is the radioactive decay of highly charged ions: For instance the β-decay into bound atomic states, which is not possible for neutral atoms, was studied for stored naked Dy ions. (orig.)

  10. Measurement of Systematic Error Effects for a Sensitive Storage Ring EDM Polarimeter

    Science.gov (United States)

    Imig, Astrid; Stephenson, Edward

    2009-10-01

    The Storage Ring EDM Collaboration was using the Cooler Synchrotron (COSY) and the EDDA detector at the Forschungszentrum J"ulich to explore systematic errors in very sensitive storage-ring polarization measurements. Polarized deuterons of 235 MeV were used. The analyzer target was a block of 17 mm thick carbon placed close to the beam so that white noise applied to upstream electrostatic plates increases the vertical phase space of the beam, allowing deuterons to strike the front face of the block. For a detector acceptance that covers laboratory angles larger than 9 ^o, the efficiency for particles to scatter into the polarimeter detectors was about 0.1% (all directions) and the vector analyzing power was about 0.2. Measurements were made of the sensitivity of the polarization measurement to beam position and angle. Both vector and tensor asymmetries were measured using beams with both vector and tensor polarization. Effects were seen that depend upon both the beam geometry and the data rate in the detectors.

  11. Considerations on the application in supermarkets. The high performance air cooler in the course of time; Ueberlegungen fuer die Anwendung im Supermarkt. Der Hochleistungsluftkuehler im Wandel der Zeit

    Energy Technology Data Exchange (ETDEWEB)

    Lich, Mathias [GEA Kueba GmbH, Baierbrunn (Germany)

    2011-08-15

    In the last twenty years, the high performant air cooler has undergone a rapid development. Power, energy efficiency and compact size an important role in the selection for the application in the supermarket. The development of the technology of EC fans shows that there always are potentials for an optimal development of products. While an air cooler needed a current consumption of 180 W for the fan twenty years ago, now significantly less than 100 W are necessary. Fan diameter, pipe diameter, shell size and all incorporated components have become more powerful and more efficient.

  12. Proton accumulator ring injection studies

    International Nuclear Information System (INIS)

    Cooper, R.K.; Neil, V.K.

    1977-01-01

    Protons may be created in an accelerator or storage ring by stripping electrons from neutral hydrogen atoms that have been injected into the machine. Because Liouville's theorem is violated by this type of injection, particles may be continually injected into a region of phase space that is already populated, and the density in that region increases with time. A computational investigation was made of the evolution of the distribution of particles in longitudinal phase space during such an injection process for a storage ring operating below the transition energy. In one calculation, an rf cavity is present in the ring and particles are injected into the stable phase region once each revolution. The purpose of this calculation is to determine the rf voltage necessary to overcome the longitudinal self-forces and contain the particles within the region of stable phase. In a second calculation, the rf is turned off, so that there is spreading in azimuth of the injected particles (i.e., de-bunching). The de-bunching occurs because of the initial energy spread and the action of the self-forces. One purpose of the calculation is to determine the total energy spread after a given number of revolutions. Another purpose is to elucidate the effect of finite resistance in the vacuum tank walls. For sufficiently high current, the finite resistance can cause bunching of a beam that is initially uniform in azimuth. Therefore it might be expected that the finite resistance would inhibit or prevent de-bunching once the number of particles injected reaches some threshold, and that this threshold would depend upon the energy spread in the beam

  13. Interaction of ring dark solitons with ring impurities in Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Xue Jukui

    2005-01-01

    The interaction of ring dark solitons/vortexes with the ring-shaped repulsive and attractive impurities in two-dimensional Bose-Einstein condensates is investigated numerically. Very rich interaction phenomena are obtained, i.e., not only the interaction between the ring soliton and the impurity, but also the interaction between vortexes and the impurity. The interaction characters, i.e., snaking of ring soliton, quasitrapping or reflection of ring soliton and vortexes by the impurity, strongly depend on initial ring soliton velocity, impurity strength, initial position of ring soliton and impurity. The numerical results also reveal that ring dark solitons/vortexes can be trapped and dragged by an adiabatically moving attractive ring impurity

  14. Polyurethane Foams with Pyrimidine Rings

    Directory of Open Access Journals (Sweden)

    Kania Ewelina

    2014-09-01

    Full Text Available Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthetic composition. The thermal resistance was studied by dynamic and static methods with concomitant monitoring of compressive strength. The polyurethane foams have similar physical properties as the classic ones except their enhanced thermal resistance. They stand long-time heating even at 200°C. Moreover thermal exposition of foams results generally in increase of their compressive strength.

  15. Longitudinal dynamics in storage rings

    International Nuclear Information System (INIS)

    Colton, E.P.

    1986-01-01

    The single-particle equations of motion are derived for charged particles in a storage ring. Longitudinal space charge is included in the potential assuming an infinitely conducting circular beam pipe with a distributed inductance. The framework uses Hamilton's equations with the canonical variables phi and W. The Twiss parameters for longitudinal motion are also defined for the small amplitude synchrotron oscillations. The space-charge Hamiltonian is calculated for both parabolic bunches and ''matched'' bunches. A brief analysis including second-harmonic rf contributions is also given. The final sections supply calculations of dynamical quantities and particle simulations with the space-charge effects neglected

  16. Storage ring proton EDM experiment

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    sensitivity of 10^-29 e-cm.  The strength of the method originates from the fact that there are high intensity polarized proton beams available and the fact that the so-called geometric phase systematic error background cancels with clock-wise and counter-clock-wise storage possible in electric rings. The ultimate sensitivity of the method is 10^-30 e-cm. At this level it will either detect a non-zero EDM or it will eliminate electro-weak baryogenesis.

  17. Ring with changeable radiation dosimeter

    International Nuclear Information System (INIS)

    Collica, C.; Epifano, L.; Farella, R.

    1976-01-01

    A ring for housing a disc of radiation measuring material is described comprising a band having a circular shape and a housing integral with the band. The housing comprises a hollow cylindrical section substantially normal to the band surface and terminating in an inwardly disposed annular flange which defines a substantially circular aperture. In a preferred embodiment of the invention a retaining protrusion formed on the inside of the cylindrical section and spaced from the annular flange is provided to retain a plurality of discs mounted in the housing in layered fashion

  18. Ring magnet firing angle control

    International Nuclear Information System (INIS)

    Knott, M.J.; Lewis, L.G.; Rabe, H.H.

    1975-01-01

    A device is provided for controlling the firing angles of thyratrons (rectifiers) in a ring magnet power supply. A phase lock loop develops a smooth ac signal of frequency equal to and in phase with the frequency of the voltage wave developed by the main generator of the power supply. A counter that counts from zero to a particular number each cycle of the main generator voltage wave is synchronized with the smooth AC signal of the phase lock loop. Gates compare the number in the counter with predetermined desired firing angles for each thyratron and with coincidence the proper thyratron is fired at the predetermined firing angle

  19. Interaction of Vortex Ring with Cutting Plate

    Science.gov (United States)

    Musta, Mustafa

    2015-11-01

    The interaction of a vortex ring impinging on a thin cutting plate was made experimentally using Volumetric 3-component Velocitmetry (v3v) technique. The vortex rings were generated with piston-cylinder vortex ring generator using piston stroke-to-diameter ratios and Re at 2-3 and 1500 - 3000, respectively. The cutting of vortex rings below center line leads to the formation of secondary vortices on each side of the plate which is look like two vortex rings, and a third vortex ring propagates further downstream in the direction of the initial vortex ring, which is previously showed by flow visualization study of Weigand (1993) and called ``trifurcation''. Trifurcation is very sensitive to the initial Reynolds number and the position of the plate with respect to the vortex ring generator pipe. The present work seeks more detailed investigation on the trifurcation using V3V technique. Conditions for the formation of trifurcation is analyzed and compared with Weigand (1993). The formed secondary vortex rings and the propagation of initial vortex ring in the downstream of the plate are analyzed by calculating their circulation, energy and trajectories.

  20. Multi Channels PWM Controller for Thermoelectric Cooler Using a Programmable Logic Device and Lab-Windows CVI

    Directory of Open Access Journals (Sweden)

    Eli FLAXER

    2008-09-01

    Full Text Available We present a complete design of a multi channels PID controller for Thermoelectric Cooler (TEC using a pulse width modulation (PWM technique implemented by a dedicated programmable logic device (PLD programmed by VHDL. The PID control loop is implemented by software written by National Instrument Lab-Windows CVI. Due to the fact that the implementation is by a VHDL and PLD the design is modular, as a result, the circuit is very compact in size and very low cost as compared to any commercial product. In addition, since the control loop is implemented by software running on a personal computer (PC using a C language, it is easy to adjust the controller to various environmental conditions and for a width range of sensors like: a thermo couple (TC, thermistor, resistance temperature detectors (RTD etc. We demonstrate the performance of this circuit as a controller for a small incubator using thermistor as the temperature sensor.

  1. A study on the effects of system pressure on heat and mass transfer rates of an air cooler

    International Nuclear Information System (INIS)

    Jung, Hyung Ho

    2002-01-01

    In the present paper, the effects of inlet pressure on the heat and mass transfer rates of an air cooler are numerically predicted by a local analysis method. The pressures of the moist air vary from 2 to 4 bars. The psychometric properties such as dew point temperature, relative humidity and humidity ratio are employed to treat the condensing water vapor in the moist air when the surface temperatures are dropped below the dew point. The effects of the inlet pressures on the heat transfer rate, the dew point temperature, the rate of condensed water, the outlet temperature of air and cooling water are calculated. The condensation process of water vapor is discussed in detail. The results of present calculations are compared with the test data and shows good agreements

  2. Sorghum Landrace Collections from Cooler Regions of the World Exhibit Magnificent Genetic Differentiation and Early Season Cold Tolerance

    Directory of Open Access Journals (Sweden)

    Frank Maulana

    2017-05-01

    Full Text Available Cold temperature is an important abiotic stress affecting sorghum production in temperate regions. It reduces seed germination, seedling emergence and seedling vigor thus limiting the production of the crop both temporally and spatially. The objectives of this study were (1 to assess early season cold temperature stress response of sorghum germplasm from cooler environments and identify sources of tolerance for use in breeding programs, (2 to determine population structure and marker-trait association among these germplasms for eventual development of marker tools for improving cold tolerance. A total of 136 sorghum accessions from cooler regions of the world were phenotyped for seedling growth characteristics under cold temperature imposed through early planting. The accessions were genotyped using 67 simple sequence repeats markers spanning all ten linkage groups of sorghum, of which 50 highly polymorphic markers were used in the analysis. Genetic diversity and population structure analyses sorted the population into four subpopulations. Several accessions distributed in all subpopulations showed either better or comparable level of tolerance to the standard cold tolerance source, Shan qui red. Association analysis between the markers and seedling traits identified markers Xtxp34, Xtxp88, and Xtxp319 as associated with seedling emergence, Xtxp211 and Xtxp304 with seedling dry weight, and Xtxp20 with seedling height. The markers were detected on chromosomes previously found to harbor QTLs associated with cold tolerance in sorghum. Once validated these may serve as genomic tools in marker-assisted breeding or for screening larger pool of genotypes to identify additional sources of cold tolerance.

  3. The cryogenic storage ring CSR

    Science.gov (United States)

    von Hahn, R.; Becker, A.; Berg, F.; Blaum, K.; Breitenfeldt, C.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Heber, O.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S.; Meyer, C.; Mishra, P. M.; Novotný, O.; O'Connor, A. P.; Orlov, D. A.; Rappaport, M. L.; Repnow, R.; Saurabh, S.; Schippers, S.; Schröter, C. D.; Schwalm, D.; Schweikhard, L.; Sieber, T.; Shornikov, A.; Spruck, K.; Sunil Kumar, S.; Ullrich, J.; Urbain, X.; Vogel, S.; Wilhelm, P.; Wolf, A.; Zajfman, D.

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm-3 is derived, equivalent to a room-temperature pressure below 10-14 mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  4. The cryogenic storage ring CSR.

    Science.gov (United States)

    von Hahn, R; Becker, A; Berg, F; Blaum, K; Breitenfeldt, C; Fadil, H; Fellenberger, F; Froese, M; George, S; Göck, J; Grieser, M; Grussie, F; Guerin, E A; Heber, O; Herwig, P; Karthein, J; Krantz, C; Kreckel, H; Lange, M; Laux, F; Lohmann, S; Menk, S; Meyer, C; Mishra, P M; Novotný, O; O'Connor, A P; Orlov, D A; Rappaport, M L; Repnow, R; Saurabh, S; Schippers, S; Schröter, C D; Schwalm, D; Schweikhard, L; Sieber, T; Shornikov, A; Spruck, K; Sunil Kumar, S; Ullrich, J; Urbain, X; Vogel, S; Wilhelm, P; Wolf, A; Zajfman, D

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  5. The cryogenic storage ring CSR

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R. von; Becker, A.; Berg, F.; Blaum, K.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); and others

    2016-06-15

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm{sup −3} is derived, equivalent to a room-temperature pressure below 10{sup −14} mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  6. Dynamical Evolution of Ring-Satellite Systems

    Science.gov (United States)

    Ohtsuki, Keiji

    2005-01-01

    The goal of this research was to understand dynamical processes related to the evolution of size distribution of particles in planetary rings and application of theoretical results to explain features in the present rings of giant planets. We studied velocity evolution and accretion rates of ring particles in the Roche zone. We developed a new numerical code for the evolution of ring particle size distribution, which takes into account the above results for particle velocity evolution and accretion rates. We also studied radial diffusion rate of ring particles due to inelastic collisions and gravitational encounters. Many of these results can be also applied to dynamical evolution of a planetesimal disk. Finally, we studied rotation rates of moonlets and particles in planetary rings, which would influence the accretional evolution of these bodies. We describe our key accomplishments during the past three years in more detail in the following.

  7. Foundations of commutative rings and their modules

    CERN Document Server

    Wang, Fanggui

    2016-01-01

    This book provides an introduction to the basics and recent developments of commutative algebra. A glance at the contents of the first five chapters shows that the topics covered are ones that usually are included in any commutative algebra text. However, the contents of this book differ significantly from most commutative algebra texts: namely, its treatment of the Dedekind–Mertens formula, the (small) finitistic dimension of a ring, Gorenstein rings, valuation overrings and the valuative dimension, and Nagata rings. Going further, Chapter 6 presents w-modules over commutative rings as they can be most commonly used by torsion theory and multiplicative ideal theory. Chapter 7 deals with multiplicative ideal theory over integral domains. Chapter 8 collects various results of the pullbacks, especially Milnor squares and D+M constructions, which are probably the most important example-generating machines. In Chapter 9, coherent rings with finite weak global dimensions are probed, and the local ring of weak gl...

  8. A first course in noncommutative rings

    CERN Document Server

    Lam, T Y

    2001-01-01

    A First Course in Noncommutative Rings, an outgrowth of the author's lectures at the University of California at Berkeley, is intended as a textbook for a one-semester course in basic ring theory. The material covered includes the Wedderburn-Artin theory of semisimple rings, Jacobson's theory of the radical, representation theory of groups and algebras, prime and semiprime rings, local and semilocal rings, perfect and semiperfect rings, etc. By aiming the level of writing at the novice rather than the connoisseur and by stressing th the role of examples and motivation, the author has produced a text that is suitable not only for use in a graduate course, but also for self- study in the subject by interested graduate students. More than 400 exercises testing the understanding of the general theory in the text are included in this new edition.

  9. Report of the eRHIC Ring-Ring Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-10-13

    This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.

  10. A muon storage ring for neutrino beams

    International Nuclear Information System (INIS)

    Lee, W.; Neuffer, D.

    1988-01-01

    A muon storage ring can provide electron and muon neutrino beams of precisely knowable flux. Constraints on muon collection and storage-ring design are discussed. Sample muon storage rings are presented and muon and neutrino intensities are estimated. Experimental use of the ν-beams, detector properties, and possible variations are described. Future directions for conceptual designs are outlined. 11 refs., 4 figs., 3 tabs

  11. Storage rings, internal targets and PEP

    International Nuclear Information System (INIS)

    Spencer, J.E.

    1986-11-01

    Storage rings with internal targets are described, using PEP as an example. The difference between electrons and heavier particles such as protons, antiprotons, and heavy ions is also discussed because it raises possibilities of bypass insertions for more exotic experiments. PEP is compared to other rings in various contexts to verify the assertion that it is an ideal ring for many fundamental and practical applications that can be carried on simultaneously

  12. Saturn’s ring temperatures at equinox

    Science.gov (United States)

    Spilker, Linda J.; Ferrari, C.; Morishima, R.

    2013-10-01

    Modeling the thermal emission of Saturn's rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, the main rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to reproduce the temperatures observed with the Cassini CIRS instrument around equinox in August 2009. A simple semi-analytic model which includes mutual shadowing effects can mostly explain the radial profile of the equinox ring temperatures, except the model predicts lower temperatures than those observed for the A ring. The temperature variation at a given saturnocentric radius is primarily caused by observational geometry variations relative to Saturn. The observed temperature increases with decreasing Saturn-ring-observer angle. In addition, we found evidence that the leading hemispheres of particles are warmer than the trailing hemispheres at least for the C ring and probably for the A and B rings as well. This is explained if some fraction of particles has spin rates lower than the synchronous rotation rate as predicted by N-body simulations. The spin model for a monolayer ring (Ferrari, C., Leyrat, C., 2006, Astron. Astrophys. 447, 745-760) can fit the temperature variations with spacecraft longitude observed in the C ring with currently known thermal properties and a mixing of slow and fast rotators. The multilayer model (Morishima, R., Salo, H., Ohtsuki, K., 2009, Icarus 201, 634-654) can reproduce the temperatures of the B and C rings but gives A ring temperatures that are significantly lower than those observed as does the simple semi-analytic model. More advanced models which take into account self-gravity wakes may explain the A ring temperature behavior.

  13. Ring recognition in the CBM RICH detector

    International Nuclear Information System (INIS)

    Lebedev, S.; Ososkov, G.; Hoehne, C.

    2007-01-01

    Two algorithms of ring recognition, a standalone ring finder (using only RICH information) and an algorithm based on the information from vertex tracks are described. The fake ring problem and its solution using a set of two-dimensional cuts or an artificial neural network are discussed. Results of a comparative study are given. All developed algorithms were tested on large statistics of simulated events and were then included into the CBM framework for common use

  14. On Semiprime Noetherian PI-Rings

    OpenAIRE

    Chiba, Katsuo

    2000-01-01

    Let R be a semiprime Noetherian PI-ring and Q(R) the semisimple Artinian ring of fractions of R. We shall prove the following conditions are equivalent: (1) the Krull dimention of R is at most one, (2) Any ring between R and Q(R) is again right Noetherian, (3) Let a, b be central regular elements of Q(R). Then the subring R + aR[b] of Q(R) is right Noetherian.

  15. Design of Piston Ring Friction Tester Apparatus

    DEFF Research Database (Denmark)

    Klit, Peder

    2006-01-01

    One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing the frictio......One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing...... the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. For piston rings the external load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount...... available is reflected in the friction absorbed in the bearing. The following properties will be measured: Oil fillm thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands...

  16. Multiplication modules over non-commutative rings

    International Nuclear Information System (INIS)

    Tuganbaev, A A

    2003-01-01

    It is proved that each submodule of a multiplication module over a regular ring is a multiplicative module. If A is a ring with commutative multiplication of right ideals, then each projective right ideal is a multiplicative module, and a finitely generated A-module M is a multiplicative module if and only if all its localizations with respect to maximal right ideals of A are cyclic modules over the corresponding localizations of A. In addition, several known results on multiplication modules over commutative rings are extended to modules over not necessarily commutative rings

  17. Influence of topology in a quantum ring

    International Nuclear Information System (INIS)

    Netto, A.L. Silva; Chesman, C.; Furtado, C.

    2008-01-01

    In this Letter we study the quantum rings in the presence of a topological defect. We use geometric theory of defects to describe one and two-dimensional quantum rings in the presence of a single screw dislocation. In addition we consider some potential in a two dimensional ring and calculate their energy spectrum. It is shown that the energy spectrum depend on the parabolic way on the burgers vectors of the screw dislocation. We also show that the presence of a topological defect introduces a new contribution for the Aharonov-Bohm effect in the quantum ring

  18. Topological matter, integrable models and fusion rings

    International Nuclear Information System (INIS)

    Nemeschansky, D.; Warner, N.P.

    1992-01-01

    We show how topological G k /G k models can be embedded into the topological matter models that are obtained by perturbing the twisted N = 2 supersymmetric, hermitian symmetric, coset models. In particular, this leads to an embedding of the fusion ring of G as a sub-ring of the perturbed, chiral primary ring. The perturbation of the twisted N = 2 model that leads to the fusion ring is also shown to lead to an integrable N = 2 supersymmetric field theory when the untwisted N = 2 superconformal field theory is perturbed by the same operator and its hermitian conjugate. (orig.)

  19. Corneal iron ring after hyperopic photorefractive keratectomy.

    Science.gov (United States)

    Bilgihan, K; Akata, F; Gürelik, G; Adigüzel, U; Akpinar, M; Hasanreisoğlu, B

    1999-05-01

    To report the incidence and course of corneal iron deposition after hyperopic photorefractive keratectomy (PRK). Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. Between January 1995 and December 1997, 62 eyes had PRK to correct hyperopia. Nine eyes developed corneal iron ring 5 to 8 months (mean 6.25 months +/- 1.3 [SD]) after PRK for hyperopia. The rings persisted during the mean follow-up of 19 +/- 11.09 months. The ring-shaped iron deposition after PRK for hyperopia must be differentiated from the Fleischer ring. Our results suggest that the slitlamp findings of peripheral corneal iron deposition in hyperopic PRK patients correlate with achieved correction.

  20. Status of the SLC damping rings

    International Nuclear Information System (INIS)

    Hutton, A.M.; Davies-White, W.A.; Delahaye, J.P.

    1985-06-01

    Electron beams of full design energy 1.21 GeV and nearly full design intensity 4 x 10 10 particles/pulse (design 5 x 10 10 ) have been extracted from the Stanford Linac and successfully stored in the electron damping ring. Beams of less intensity have been extracted from the ring and reinjected into the Linac. The present intensity limits are not thought to be fundamental. The operating experience with the electron ring and the status of the construction of the positron ring will be discussed. 11 refs., 1 fig., 2 tabs

  1. Hybrid coolers allow important water saving; Les refroidisseurs ''hybrides'' permettent des economies d'eau importantes

    Energy Technology Data Exchange (ETDEWEB)

    Bitsch, V. [Societe Jaeggi-France (France)

    2005-03-01

    Air cooling systems used with refrigerating machineries are in general highly water and electricity consuming. The use of 'hybrid' systems having the characteristics of both close-cycle evaporative systems and dry coolers allow important water saving. This article presents the operation principle and characteristics of such cooling systems. (J.S.)

  2. 10 CFR 431.304 - Uniform test method for the measurement of energy consumption of walk-in coolers and walk-in...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform test method for the measurement of energy consumption of walk-in coolers and walk-in freezers. 431.304 Section 431.304 Energy DEPARTMENT OF ENERGY... measuring, pursuant to EPCA, the energy consumption of refrigerated bottled or canned beverage vending...

  3. Dwarfs Cooler Than M: The Definition of Spectral Type L Using Discoveries form the 2-Micron All-Sky Survey (2MASS)

    Science.gov (United States)

    Kirkpatrick, J.; Reid, I.; Liebert, J.; Cutri, R.; Nelson, B.; Beichan, C.; Dahn, C.; Monet, D.; Gizis, J.; Skrutskie, M.

    2000-01-01

    Because the TiO and VO bands, which dominate the far-optical portions of late-M spectra, disappear in these cooler dwarfs, we define a new spectral class L in wich metallic oxides are replaced by metallic hydrides and neutral alkali metals as the major spectroscopic signatures.

  4. Control of ring lasers by means of coupled cavities

    DEFF Research Database (Denmark)

    Buchhave, Preben; Abitan, Haim; Tidemand-Lichtenberg, Peter

    2000-01-01

    Variable phase coupling to an external ring is used to control a unidirectional ring laser. The observed behavior of the coupled rings is explained theoretically. We have found experimentally that by quickly changing the phase of the feedback from the external ring it is possible to Q......-switch the ring laser. Also, at certain values of the phase of the feedback in the external ring, instabilities in the total system occur and oscillations arise in the ring laser....

  5. The Conversion of Wiswesser Line Notations to Ring Codes. I. The Conversion of Ring Systems

    Science.gov (United States)

    Granito, Charles E.; And Others

    1972-01-01

    The computerized conversion of Wiswesser Line Notations to Ring Codes, using a two-part approach, and the set of computer programs generated for the conversion of ring systems are described. (9 references) (Author)

  6. Detailed description of the Ócsa Bird Ringing Station, Hungary

    Directory of Open Access Journals (Sweden)

    Csörgő Tibor

    2016-12-01

    Full Text Available The present paper acts as an introduction to a series that will describe the exploratory analyses of migration phenology and morphometrics of the most common passerine species at the Ócsa Bird Ringing Station. This station is situated in the Ócsa Landscape Protection Area that belongs to the Duna–Ipoly National Park, Hungary. The area is somewhat cooler and more humid than the surrounding agricultural fields and tree plantations, covered by a mosaic of diverse hygrophilous vegetation patches. Bird trapping is mostly based on Japanese mist-net lines crossing different plant communities. During the period of 1984–2015, a total of 422,862 birds were trapped and ringed here, while 202,739 local, 1,235 within country, and 443 foreign recaptures were also recorded. Each bird is characterized by the following data: location and time of capture, species, age, sex, scores of fat, pectoral muscle, wing tip abrasion, and moult, length of wing, 3rd primary, and tail, and body mass. After subjected to a rigorous quality check, digital data are deposited in the archive of the Hungarian Bird Ringing Centre, and the EURING data base. From time to time, other research projects also utilized the accessibility of wild birds captured here, thus collection of blood samples, ecto- and endoparasites was carried out at the station. The relatively long time span, large number of species and individuals, and the readily available environmental (weather, vegetation, etc. data makes the avian data collected here a suitable base for studies of various disciplines like capture methodology, habitat preferences, breeding, migration, and wintering, effects of weather and climate change, and epidemiology of viruses and parasites.

  7. The ring plus project: safety and acceptability of vaginal rings that protect women from unintended pregnancy

    OpenAIRE

    Schurmans, C?line; De Baetselier, Irith; Kestelyn, Evelyne; Jespers, Vicky; Delvaux, Th?r?se; Agaba, Stephen K; van Loen, Harry; Menten, Joris; van de Wijgert, Janneke; Crucitti, Tania

    2015-01-01

    Background Research is ongoing to develop multipurpose vaginal rings to be used continuously for contraception and to prevent Human Immunodeficiency Virus (HIV) infection. Contraceptive vaginal rings (CVRs) are available in a number of countries and are most of the time used intermittently i.e. three weeks out of a 4-week cycle. Efficacy trials with a dapivirine-containing vaginal ring for HIV prevention are ongoing and plans to develop multi-purpose vaginal rings for prevention of both HIV a...

  8. Low-emittance Storage Rings

    CERN Document Server

    Wolski, Andrzej

    2014-01-01

    The effects of synchrotron radiation on particle motion in storage rings are discussed. In the absence of radiation, particle motion is symplectic, and the beam emittances are conserved. The inclusion of radiation effects in a classical approximation leads to emittance damping: expressions for the damping times are derived. Then, it is shown that quantum radiation effects lead to excitation of the beam emittances. General expressions for the equilibrium longitudinal and horizontal (natural) emittances are derived. The impact of lattice design on the natural emittance is discussed, with particular attention to the special cases of FODO-, achromat- and theoretical-minimum-emittance-style lattices. Finally, the effects of betatron coupling and vertical dispersion (generated by magnet alignment and lattice tuning errors) on the vertical emittance are considered.

  9. Main ring transition crossing simulations

    International Nuclear Information System (INIS)

    Kourbanis, I.; Ng, King-Yuen.

    1990-10-01

    We used ESME to simulate transition crossing in the Main Ring (MR). For the simulations, we followed the MR 29 cycle used currently for bar p production with a flat top of 120 GeV. In Sect. II, some inputs are discussed. In Sect. III, we present simulations with space charge turned off so that the effect of nonlinearity can be studied independently. When space charge is turned on in Sect. IV, we are faced with the problem of statistical errors due to binning, an analysis of which is given in the Appendices. Finally in Sects. V and VI, the results of simulations with space charge are presented and compared with the experimental measurements. 7 refs., 6 figs

  10. Performance improvement of a hybrid air conditioning system using the indirect evaporative cooler with internal baffles as a pre-cooling unit

    Directory of Open Access Journals (Sweden)

    A.E. Kabeel

    2017-12-01

    Full Text Available In the present paper, the effects of the indirect evaporative cooler with internal baffle on the performance of the hybrid air conditioning system are numerically investigated. The hybrid air conditioning system contains two indirect evaporative coolers with internal baffle, one is utilized to pre-cool the air inlet to the desiccant wheel and the other is utilized to pre-cool the supply air inlet to the room. The effects of the inlet conditions of the process and reactivation air and working air ratio on the thermal performance of the hybrid air conditioning system have been analyzed. The results of this study show that in the hybrid air conditioning system for using the indirect evaporative cooler with internal baffle as a pre-cooling unit, the supply air temperature reduced by 21% and the coefficient of performance improved by 71% as compared to previous designs of the hybrid air conditioning system at the same inlet conditions. For increasing process air inlet temperature from 25 °C to 45 °C, supply air temperature increases from 12.7 °C to 14.2 °C, thermal COP increases from 1.87 to 2.84, and supply air relative humidity increases from 76.7% to 77.4%. Also, for increasing the reactivation air inlet temperature from 70 °C to 110 °C, supply air temperature dropped from 15.9 °C to 10.9 °C, supply air relative humidity dropped from 82.7% to 71.8%, and thermal COP dropped from 4.5 to 1.7. The recommended optimal air working ratio in the indirect evaporative cooler with internal baffle should be 0.15. Keywords: Desiccant material, Solar air collector, Evaporative cooler, Internal baffles, Air conditioning

  11. VUV optical ring resonator for Duke storage ring free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others

    1995-12-31

    The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

  12. Influence of ring growth rate on damage development in hot ring rolling

    NARCIS (Netherlands)

    Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

    2015-01-01

    As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For

  13. The King's Ring: A Matter of Trust

    DEFF Research Database (Denmark)

    Sterrett, Joseph William

    2018-01-01

    This essay examines the material and social effects of an exchange of trust between a king, Henry VIII, and his counsellor, Thomas Cranmer in Shakespeare and Fletcher’s All is True. The ring that the King gives Cranmer is both nothing and everything: nothing in that it could be anything, any ring...

  14. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.

    2009-06-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  15. Hawking radiation of black rings from anomalies

    International Nuclear Information System (INIS)

    Chen Bin; He Wei

    2008-01-01

    We derive Hawking radiation of five-dimensional black rings from gauge and gravitational anomalies using the method proposed by Robinson and Wilczek. We find, as in the black hole case, that the problem could reduce to a (1+1)-dimensional field theory and the anomalies result in correct Hawking temperature for neutral, dipole and charged black rings

  16. IAG ring test animal proteins 2016

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Rhee, van de N.E.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.; Pinckaers, V.G.Z.

    2016-01-01

    The annual ring test for the detection of animal proteins in animal feed of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy was organized by RIKILT - Wageningen UR, The Netherlands. The aim of the ring study was to provide the participants information

  17. Reversible decay of ring dark solitons

    International Nuclear Information System (INIS)

    Toikka, L A; Suominen, K-A

    2014-01-01

    We show how boundary effects can cause a Bose–Einstein condensate to periodically oscillate between a (circular) array of quantized vortex–antivortex pairs and a (ring) dark soliton. If the boundary is restrictive enough, the ring dark soliton becomes long-lived. (paper)

  18. The multi-bend achromat storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Mikael [MAX IV Laboratory Ole Römers v. 1 22100 Lund Sweden (Sweden)

    2016-07-27

    Not very long ago, the 3{sup rd} generation storage ring technology was judged as mature. Most of the 3{sup rd} generation storage rings used the Double-Bend Achromat (DBA) or Triple-Bend Achromat (TBA) concepts. It was however a well-known fact that increasing the number of magnet cells in the rings is a powerful way of decreasing the electron beam emittance and thus the source brilliance, but at the penalty of increasing the size and cost of the rings. Preserving the Dynamic Aperture (DA) in the rings became also an issue when increasing the number of magnet cells. The Multi-Bend Achromat (MBA) concept, including a miniaturization of the ring elements, has now drastically changed the picture. The MBA rings, now in construction or being planned, offer orders of magnitudes higher brilliance than rings of conventional designs. Several light sources around the world are now implementing or planning to implement this MBA concept. This article touches on the science drivers for higher brilliance. We will then describe the MBA concept with its advantages as well as its challenges. A short survey of the MBA activity around the world will also be presented. The author apologies for focusing on the MAX IV project regarding technical solutions. This is motivated by that MAX IV is the facility he knows best and it might be regarded as a fore-runner for the MBA concept.

  19. Collective effects in isochronous storage rings

    International Nuclear Information System (INIS)

    Chao, A.W.; Kim, K.-J.

    1996-01-01

    We studied the collective instabilities in isochronous storage rings using a linac-type analysis. Simple criteria for avoiding the longitudinal and transverse instabilities are developed by employing a two-particle model. Numerical examples show that these conditions do not impose serious performance restrictions for two of the currently proposed isochronous storage rings

  20. Local duality for 2-dimensional local ring

    Indian Academy of Sciences (India)

    dimensional complete local ring whose residue field is an n-dimensional local field in the sense of. Kato–Parshin. Our results generalize the Saito works in the case n = 0 and are applied to study the Bloch–Ogus complex for such rings in various cases.