WorldWideScience

Sample records for actively cooled be-cu

  1. Pre-irradiation testing of actively cooled Be-Cu divertor modules

    Energy Technology Data Exchange (ETDEWEB)

    Linke, J.; Duwe, R.; Kuehnlein, W. [Forschungszentrum Juelich GmbH (Germany)] [and others

    1995-09-01

    A set of neutron irradiation tests is prepared on different plasma facing materials (PFM) candidates and miniaturized components for ITER. Beside beryllium the irradiation program which will be performed in the High Flux Reactor (HFR) in Petten, includes different carbon fiber composites (CFQ) and tungsten alloys. The target values for the neutron irradiation will be 0.5 dpa at temperatures of 350{degrees}C and 700{degrees}C, resp.. The post irradiation examination (PIE) will cover a wide range of mechanical tests; in addition the degradation of thermal conductivity will be investigated. To determine the high heat flux (HHF) performance of actively cooled divertor modules, electron beam tests which simulate the expected heat loads during the operation of ITER, are scheduled in the hot cell electron beam facility JUDITH. These tests on a selection of different actively cooled beryllium-copper and CFC-copper divertor modules are performed before and after neutron irradiation; the pre-irradiation testing is an essential part of the program to quantify the zero-fluence high heat flux performance and to detect defects in the modules, in particular in the brazed joints.

  2. Elastocaloric cooling: Stretch to actively cool

    Science.gov (United States)

    Ossmer, Hinnerk; Kohl, Manfred

    2016-10-01

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

  3. Active Cooling Of A Mobile Phone Handset

    OpenAIRE

    Grimes, Ronan; WALSH, EDMOND; Walsh, Pat

    2010-01-01

    Abstract Power dissipation levels in mobile phones continue to increase due to gaming, higher power applications, and increased functionality associated with the internet. The current cooling methodologies of natural convection and radiation limit the power dissipation within a mobile phone to between 1-2 W depending on size. As power dissipation levels increase, products such as mobile phones will require active cooling to ensure that the devices operate within an acceptable tempe...

  4. Active and passive cooling methods for dwellings

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2018-01-01

    they might be applied, and what their energy needs are. Secondly, what scientific analysis has been carried out and what the major findings are. Thirdly, what their economic and technical feasibility of use at the stage of implementation and operation within a dwelling are. Then, either with the reviewed......In this document a review of three active as well as ten passive cooling methods suitable for residential buildings is carried out. The review firstly addresses how the various technologies cool the space according to the terms of the building heat balance, under what technical conditions...... studies or with a simulation modelling, an assessment of temperature drop of each cooling method within a standard-size dwelling is carried out. Also, a comparison of initial investment, energy consumption, maintenance, retrofitting and required space is done. Thereafter, with this information, a decision...

  5. Diagnostics for the NBETF actively cooled beamdump

    Energy Technology Data Exchange (ETDEWEB)

    Theil, E.; Jacobson, V.

    1984-09-01

    Lawrence Berkeley Laboratory's Neutral Beam Engineering Test Facility is currently testing multi-megawatt beams with pulse durations of up to 30 seconds. For this purpose, an actively cooled beam dump composed of heat-absorbing panels tht dissipate the beam energy via high speed water flow has been installed and tested. The panels are mounted in a complex assembly necessary to accommodate the variety of ion sources to be tested. The beam dump required new diagnostics of two kinds: beam diagnostics that provide graphic and quantitative information about the beam, as inferred from energy transferred to the water, and panel diagnostics that provide graphic and quantitative information about the beam dump itself. In this paper we describe our response to these requirements, including new algorithms for beam profiles, and we compare this work to our earlier results for inertial beam dumps. Principal differences are that the power densities on the water-cooled panels can be only indirectly inferred from measurements of the transferred beam energy, and that the acquisition and preparation of raw data is much more complex.

  6. Modeling Atmospheric Activity of Cool Stars

    Science.gov (United States)

    Schrijver, C. J.

    2003-10-01

    This review discusses a set of simple models for cool-star activity with which we compute (1) photospheric field patterns on stars of different activity levels, (2) the associated outer-atmospheric field configurations, and (3) the soft X-ray emission that is expected to result from the ensemble of loop atmospheres in the coronae of these stars. The model is based on empirically-determined properties of solar activity. It allows us to extrapolate to stars of significantly higher and lower activity than seen on the present-day Sun through its cycle. With it, we can, for example, gain insight into stellar field patterns (including a possible formation mechanism for polar starspots), as well as in the properties of coronal heating (helpful in the identification of the quiescent coronal heating mechanism). Lacking comprehensive theoretical understanding, the model's reliance on empirical solar data means that the multitude of processes involved are approximated to be independent of rotation rate, activity level, and fundamental stellar parameters, or -- where unavoidably necessary -- assumed to simply scale with activity. An evaluation of the most important processes involved guides a discussion of the limits of the model, of the limitations in our knowledge, and of future needs. "I propose to adopt such rules as will ensure the testability of scientific statements; which is to say, their falsifiability." Karl Popper (1902-1994)

  7. Actively controlling coolant-cooled cold plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Parida, Pritish R.

    2016-04-26

    Cooling apparatuses are provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The cooling apparatus includes the cold plate and a controller. The cold plate couples to one or more electronic components to be cooled, and includes an adjustable physical configuration. The controller dynamically varies the adjustable physical configuration of the cold plate based on a monitored variable associated with the cold plate or the electronic component(s) being cooled by the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the electronic component(s), and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the cold plate, the positioning of which may be adjusted based on the monitored variable.

  8. Experimental Investigation on Active Cooling for Ceramic Matrix Composite

    Institute of Scientific and Technical Information of China (English)

    PENG Li-na; HE Guo-qiang; LIU Pei-jin

    2009-01-01

    Compared with conventional materials, the active cooling ceramic matrix composite used in ramjet or scramjet makes their structures lighter in mass and better in performance. In this paper, an active and a passive cooling refractory composite specimens are designed and tested with an experimental facility composed of multilayer smale scale cooling penel which consists of a water cooling system and a ceramic matrix composite specimen, and a gas generator used for providing lower and higher transfer rate gases to simulate the temperatures in combustion chamber of ramjst. The active cooling specimen can continuously suffer high surface temperature of 2 000K for 30s and that of 3 000 K for 9.3 s, respectively. The experiment results show that the active cooling composite structure is available for high-temperature condition in ramjet.

  9. Actively controlling coolant-cooled cold plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Parida, Pritish R.

    2015-07-28

    A method is provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The method includes: monitoring a variable associated with at least one of the coolant-cooled cold plate or one or more electronic components being cooled by the cold plate; and dynamically varying, based on the monitored variable, a physical configuration of the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the one or more electronic components, and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the coolant-cooled cold plate, the positioning of which may be adjusted based on the monitored variable.

  10. Preliminary characterization of interlayer for Be/Cu sintered compacts

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, N.; Kawamura, H. [Oarai Research Establishment, Ibaraki-ken (Japan)

    1995-09-01

    At present, beryllium is under consideration as a main candidate material for plasma facing components of ITER, because of its many advantages such as low Z, high thermal conductivity, low tritium retention, low activation and so on. Among the different divertor design options, the duplex structure where the beryllium armor is bonded with heat sink structural materials (DS-copper, Cu-Cr-Zr and so on) is under consideration. And plasma facing components will be exposed to high heat load and high neutron flux generated by the plasma. Therefore, it is necessary to develop the reliable bonding technologies between beryllium and heat sink structural materials in order to fabricate plasma facing components which can resist those. Then, we started the bonding technology development of beryllium and copper alloy with FGM (functional gradient material) in order to reduce thermal stress due to the difference of thermal expansion between beryllium and copper alloy. As the interlayers for FGM, eleven kinds of sintered compacts in which the mixing ratio of beryllium powder and oxygen free copper powder is different, were fabricated by the hot press/HIP method. The dimension of each compact is 8mm in diameter, 2mm in thickness. Then, thermal diffusivity and specific heat of these compacts were measured by laser flash method, and thermal conductivity was calculated from those values. From metalographical observation, it became clear that the sintered compacts of mixture of beryllium powder and copper powder contain residual beryllium, copper and two kinds of intermetallic compounds, Be{sub 2}Cu({delta}) and BeCu({gamma}). From the results of thermal characterization, thermal diffusivity of interlayers increased with increase of copper containing ratio. And, specific heat gradually decreased with increase of copper containing ratio.

  11. Study of active cooling for supersonic transports

    Science.gov (United States)

    Brewer, G. D.; Morris, R. E.

    1975-01-01

    The potential benefits of using the fuel heat sink of hydrogen fueled supersonic transports for cooling large portions of the aircraft wing and fuselage are examined. The heat transfer would be accomplished by using an intermediate fluid such as an ethylene glycol-water solution. Some of the advantages of the system are: (1) reduced costs by using aluminum in place of titanium, (2) reduced cabin heat loads, and (3) more favorable environmental conditions for the aircraft systems. A liquid hydrogen fueled, Mach 2.7 supersonic transport aircraft design was used for the reference uncooled vehicle. The cooled aircraft designs were analyzed to determine their heat sink capability, the extent and location of feasible cooled surfaces, and the coolant passage size and spacing.

  12. Be-Cu gradient materials through controlled segregation. Basic investigations

    Energy Technology Data Exchange (ETDEWEB)

    Muecklich, F.; Lorinser, M.; Hartmann, S.; Beinstingel, S. [Saarland Univ., Saarbruecken (Germany); Linke, J.; Roedig, M.

    1998-01-01

    The joining of materials has a fundamental problematic nature: Creating a sharp interface between two different materials causes a more or less extreme jump in the properties at this point. This may result in the failure of the component under mechanical or thermal loads. In some cases there are further difficulties caused by using a third component (e.g. the transformation of Ag-lead into Cd by neutron beams). The solution may be the creating of a functionally gradient material (FGM) Be-Cu. We discuss the advantage of such a FGM and the probabilities of an new procedure for manufacturing 1-dimensional FGMs. (author)

  13. Analysis of Heat Transfer in Actively Cooled Compound Gun Barrel

    Institute of Scientific and Technical Information of China (English)

    WU Bin; XIA Wei

    2005-01-01

    when a gun fires, a large amount of heat is brought in the barrel. Erosion/wear and security problems(self ignition of the propellant) associated with this high thermal energy have to be solved owing to the use of higher combustion gas temperature for improved cannon performance and firing at the sustained high rates. Barrel cooling technologies are the effective measures for addressing this issue. In view of the importance of having knowledge of the heat flux, an approach to calculate heat flux based on measurements was presented and validated. The calculated heat flux is used as the inner boundary condition for modeling heat transfer in a 155 mm mid-wall cooled compound gun barrel. Theoretical analysis and simulated results show that natural air cooling is dramatically slower than the forced liquid mid-wall cooling, accordingly wear life of actively cooled barrel is increased and barrel overheating is prevented.

  14. Active cooling system for Tokamak in-vessel operation manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jianjun, E-mail: yuanjj@sjtu.edu.cn; Chen, Tan; Li, Fashe; Zhang, Weijun; Du, Liang

    2015-10-15

    Highlights: • We summarized most of the challenges of fusion devices to robot systems. • Propose an active cooling system to protect all of the necessary components. • Trial design test and theoretical analysis were conducted. • Overall implementation of the active cooling system was demonstrated. - Abstract: In-vessel operation/inspection is an indispensable task for Tokamak experimental reactor, for a robot/manipulator is more capable in doing this than human being with more precise motion and less risk of damaging the ambient equipment. Considering the demanding conditions of Tokamak, the manipulator should be adaptable to rapid response in the extreme conditions such as high temperature, vacuum and so on. In this paper, we propose an active cooling system embedded into such manipulator. Cameras, motors, gearboxes, sensors, and other mechanical/electrical components could then be designed under ordinary conditions. The cooling system cannot only be a thermal shield since the components are also heat sources in dynamics. We carry out a trial test to verify our proposal, and analyze the active cooling system theoretically, which gives a direction on the optimization by varying design parameters, components and distribution. And based on thermal sensors monitoring and water flow adjusting a closed-loop feedback control of temperature is added to the system. With the preliminary results, we believe that the proposal gives a way to robust and inexpensive design in extreme environment. Further work will concentrate on overall implementation and evaluation of this cooling system with the whole inspection manipulator.

  15. Active cooling of microvascular composites for battery packaging

    Science.gov (United States)

    Pety, Stephen J.; Chia, Patrick X. L.; Carrington, Stephen M.; White, Scott R.

    2017-10-01

    Batteries in electric vehicles (EVs) require a packaging system that provides both thermal regulation and crash protection. A novel packaging scheme is presented that uses active cooling of microvascular carbon fiber reinforced composites to accomplish this multifunctional objective. Microvascular carbon fiber/epoxy composite panels were fabricated and their cooling performance assessed over a range of thermal loads and experimental conditions. Tests were performed for different values of coolant flow rate, channel spacing, panel thermal conductivity, and applied heat flux. More efficient cooling occurs when the coolant flow rate is increased, channel spacing is reduced, and thermal conductivity of the host composite is increased. Computational fluid dynamics (CFD) simulations were also performed and correlate well with the experimental data. CFD simulations of a typical EV battery pack confirm that microvascular composite panels can adequately cool battery cells generating 500 W m‑2 heat flux below 40 °C.

  16. Evaluation of Active Cooling Systems for Non-Residential Buildings

    Directory of Open Access Journals (Sweden)

    M.A. Othuman Mydin

    2014-05-01

    Full Text Available Cooling systems are an essential element in many facets of modern society including cars, computers and buildings. Cooling systems are usually divided into two types: passive and active. Passive cooling transfers heat without using any additional energy while active cooling is a type of heat transfer that uses powered devices such as fans or pumps. This paper will focus on one particular type of passive cooling: air-conditioning systems. An air-conditioning system is defined as controlled air movement, temperature, humidity and cleanliness of a building area. Air conditioning consists of cooling and heating. Therefore, the air-conditioning system should be able to add and remove heat from the area. An air-conditioning system is defined as a control or treatment of air in a confined space. The process that occurs is the air-conditioning system absorbs heat and dust while, at the same time, cleaning the air breathed into a closed space. The purpose of air-conditioning is to maintain a comfortable atmosphere for human life and to meet user requirements. In this paper, air-conditioning systems for non-residential buildings will be presented and discussed.

  17. Nondestructive Evaluation of a Be/Cu Diffusion Bond using a Shear Horizontal Wave

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hyun Kyu; Cheong, Yong Moo; Lee, Dong Won; Hong, Bong Keun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    The International Thermo-nuclear Experimental Reactor (ITER) blanket first wall includes Beryllium(Be) amour tiles joined to a CuCrZr heat sink with stainless steel cooling tubes. This first wall's panels are one of the critical components in the ITER which is exposed with a surface heat flux of 0.5 MW/m2. As a qualification program, ultrasonic test (UT) of a Be/CuCrZr diffusion bond has to be applied according to the proper procedure. Ultrasonic test can detect the presence of unbonded regions and is based on an amplitude change and a phase inversion in a signal reflected from a bond interface. The purpose of this study is to investigate the feasibility of EMAT (Electro-Magnetic Acoustic Transducer) technology for an in-situ inspection of a Be/Copper alloy joining interface under a high temperature and high radiation environment.

  18. Experimental and numerical study of open-air active cooling

    Science.gov (United States)

    Al-Fifi, Salman Amsari

    The topic of my thesis is Experimental and Numerical Study of Open Air Active Cooling. The present research is intended to investigate experimentally and Numerically the effectiveness of cooling large open areas like stadiums, shopping malls, national gardens, amusement parks, zoos, transportation facilities and government facilities or even in buildings outdoor gardens and patios. Our cooling systems are simple cooling fans with different diameters and a mist system. This type of cooling systems has been chosen among the others to guarantee less energy consumption, which will make it the most favorable and applicable for cooling such places mentioned above. In the experiments, the main focus is to study the temperature domain as a function of different fan diameters aerodynamically similar in different heights till we come up with an empirical relationship that can determine the temperature domain for different fan diameters and for different heights of these fans. The experimental part has two stages. The first stage is devoted to investigate the maximum range of airspeed and profile for three different fan diameters and for different heights without mist, while the second stage is devoted to investigate the maximum range of temperature and profile for the three different diameter fans and for different heights with mist. The computational study is devoted to built an experimentally verified mathematical model to be used in the design and optimization of water mist cooling systems, and to compare the mathematical results to the experimental results and to get an insight of how to apply such evaporative mist cooling for different places for different conditions. In this study, numerical solution is presented based on experimental conditions, such dry bulb temperature, wet bulb temperature, relative humidity, operating pressure and fan airspeed. In the computational study, all experimental conditions are kept the same for the three fans except the fan airspeed

  19. Strength of Hycon 3 HP{trademark} Be-Cu and other copper alloys from 20 C to 200 C

    Energy Technology Data Exchange (ETDEWEB)

    Weggel, R.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Francis Bitter National Magnet Lab.; Ratka, J.O.; Spiegelberg, W.D. [Brush Wellman Inc., Cleveland, OH (United States); Sakai, Yoshikazu [National Research Inst. for Metals, Ibaraki (Japan)

    1994-07-01

    To be suitable for high-performance water-cooled magnets a conductor must have an excellent combination of electrical conductivity and tensile strength at moderately elevated temperatures. The authors have measured the 0.2% yield and ultimate tensile strengths, elongation and modulus of five copper alloys, in the form of heavily cold-worked strip 0.4 mm to 1.2 mm thick, at temperatures up to 200 C. The alloys are Hycon 3 HP Be-Cu (UNS alloy C17510), a 24% silver-copper being developed by NRIM (Tsukuba, Japan), Glidcop{reg_sign}, Zr-Cu and electrolytic tough pitch copper. Be-Cu, Zr-Cu and Ag-Cu all retained strength very well. Be-Cu decreased in U.T.S. only 10% from room temperature to 200 C, Zr-Cu, 15%. For Ag-Cu the decrease was 10% from 20 to 150 C, and another 10% during the next 50 C. Glidcop weakened 20% by 150 C. So did ETP copper, whose strength then plummeted another 50% by 200 C. Except for Ag-Cu, with its filamentary microstructure, all alloys were isotropic within about 5%. The anisotropy of Ag-Cu was about 12%, with the transverse direction being the stronger.

  20. Active solar heating and cooling information user study

    Energy Technology Data Exchange (ETDEWEB)

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-01-01

    The results of a series of telephone interviews with groups of users of information on active solar heating and cooling (SHAC). An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from 19 SHAC groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Manufacturers (4 groups), Distributors, Installers, Architects, Builders, Planners, Engineers (2 groups), Representatives of Utilities, Educators, Cooperative Extension Service County Agents, Building Owners/Managers, and Homeowners (2 groups). The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  1. Annual DOE active solar heating and cooling contractors' review meeting. Premeeting proceedings and project summaries

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1981-09-01

    Ninety-three project summaries are presented which discuss the following aspects of active solar heating and cooling: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology. (LEW)

  2. Micro-Stirling Active Cooling Module (MS/ACM) for DoD Electronics Systems

    Science.gov (United States)

    2012-03-01

    Micro- Stirling Active Cooling Module (MS/ACM) for DoD Electronics Systems Douglas S. Beck Beck Engineering, Inc. 1490 Lumsden Road, Port Orchard...refrigerator. We are developing for DARPA a cm-scale Micro- Stirling Active Cooling Module (MS/ACM) micro- refrigerator to benefit the DoD systems. Under...a DARPA contract, we are designing, building, and demonstrating a breadboard MS/ACM. Keywords: Stirling ; cooler; active cooling module; micro

  3. Simulation of an active cooling system for photovoltaic modules

    Science.gov (United States)

    Abdelhakim, Lotfi

    2016-06-01

    Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

  4. Simulation of an active cooling system for photovoltaic modules

    Energy Technology Data Exchange (ETDEWEB)

    Abdelhakim, Lotfi [Széchenyi István University of Applied Sciences, Department of Mathematics, P.O.Box 701, H-9007 Győr (Hungary)

    2016-06-08

    Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

  5. Thermo Active Building Systems – Using Building Mass To Heat and Cool

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2014-01-01

    Using the thermal storage capacity of the concrete slabs between each floor in multistory buildings to heat or cool is a trend that began in the early 1990s in Switzerland.1,2 Pipes carrying water for heating and cooling are embedded in the center of the concrete slab. In central Europe (Germany......, Austria, Netherlands, etc.), this type of system has been installed in a significant number of new office buildings since the late 1990s. The trend is spreading to other parts of the world (the rest of Europe, North America and Asia). Thermo active building systems (TABS) are primarily used for cooling...... multistory buildings. By activating the building mass, there is a direct heating-cooling effect. Also, because of the thermal mass, the peak load will be reduced and some of the cooling load will be transferred beyond the time of occupancy. Because these systems for cooling operate at water temperatures...

  6. Active Cooling e-Textiles for Smart Clothing

    Institute of Scientific and Technical Information of China (English)

    Seung-A Lee; Jooyong Kim

    2006-01-01

    Cooling function is definitely one of the most desirable attributes of clothing. In spite of the recent progress on phase changing material (PCM) research, the final products with sufficient amount of cooling capability have not yet to be developed in market. A new concept of cooling fabrics has been proposed by applying "Peltier effect" to textile materials. It occurs whenever electrical current flows through two dissimilar conductors; depending on the direction of current flow, the junction of the two conductors will either absorb or release heat. This effect has been tested on P-type and N-type conducting polymers. A P-type conductive polypyrrole coated fabric was synthesized by insitu polymerization on plain weave PET to make conductive fabrics. And an N-type electrically conductive material was synthesized by treatment of MWNT and polyethyleneimine (PEI). A noticeable amount of temperature difference has been found in the fabric.

  7. Active noise canceling system for mechanically cooled germanium radiation detectors

    Science.gov (United States)

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  8. CISBAT 2007 - Active and passive cooling (natural ventilation)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This is the fourth part of the proceedings of the 2007 CISBAT conference on Renewables in a changing climate, held in Lausanne, Switzerland. On the subject of Hybrid and passive cooling the following oral contributions are summarised: 'Comparison of the thermal performance between the buried pipe system and night ventilation in residential buildings' and 'User behaviour of window control in offices during summer and winter'. Poster contributions include 'Design guidelines for housing design in Southern Brazilian climate - emphasis on energy consumption', 'The Grangettes building shows that natural ventilation and cooling brings equal or better performances than air conditioning in Geneva' and 'Little bioclimatic towers'. Further groups of presentations at the conference are reported on in separate database records. An index of authors completes the proceedings.

  9. Actively Cooled Silicon Lightweight Mirrors for Far Infrared and Submillimeter Optical Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Schafer proposes to demonstrate 2 different methods for actively cooling our 5-7.5 kg/m2 areal density Silicon Lightweight Mirrors (SLMS?) technology for future NASA...

  10. Assessment of an active liquid cooling garment intended for use in a hot environment.

    Science.gov (United States)

    Bartkowiak, Grazyna; Dabrowska, Anna; Marszalek, Anna

    2017-01-01

    This paper discusses the construction of a designed active liquid cooling garment (LCG) that has been developed in order to reduce thermal discomfort of persons working in hot environments. It consists of clothing with a tube system distributing a cooling liquid, a sensor measuring the microclimate under the clothing, and a portable cooling unit with a module controlling the temperature of the cooling liquid depending on the microclimate temperature under the clothing. The LCG was validated through tests on volunteers in a climatic chamber at 30 °C, a relative humidity of 40%, and an air movement rate of 0.4 m/s. The obtained test results confirmed the beneficial effects of the cooling system used on mean weighted skin temperature, the physical parameters of the microclimate under the clothing, and the participants' subjective assessments, as well as confirmed that the functioning of the control system regulating liquid temperature in the LCG was correct.

  11. Flightweight radiantly and actively cooled panel: Thermal and structural performance

    Science.gov (United States)

    Shore, C. P.; Nowak, R. J.; Kelly, H. N.

    1982-01-01

    A 2- by 4-ft flightweight panel was subjected to thermal/structural tests representative of design flight conditions for a Mach 6.7 transport and to off-design conditions simulating flight maneuvers and cooling system failures. The panel utilized Rene 41 heat shields backed by a thin layer of insulation to radiate away most of the 12 Btu/ft2-sec incident heating. A solution of ethylene glycol in water circulating through tubes in an aluminum-honeycomb-sandwich panel absorbed the remainder of the incident heating (0.8 Btu/sq ft-sec). The panel successfully withstood (1) 46.7 hr of radiant heating which included 53 thermal cycles and 5000 cycles of uniaxial inplane loading of + or - 1200 lfb/in; (2) simulated 2g-maneuver heating conditions and simulated cooling system failures without excessive temperatures on the structural panel; and (3) the extensive thermal/structural tests and the aerothermal tests reported in NASA TP-1595 without significant damage to the structural panel, coolant leaks, or hot-gas ingress to the structural panel.

  12. Hot Bubbles from Active Galactic Nuclei as a Heat Source in Cooling Flow Clusters

    CERN Document Server

    Brüggen, M; Brueggen, Marcus; Kaiser, Christian R.

    2002-01-01

    The hot plasma permeating clusters of galaxies often shows a central peak in the X-ray surface brightness that is coincident with a drop in entropy. This is taken as evidence for a cooling flow where the radiative cooling in the central regions of a cluster causes a slow subsonic inflow. Searches in all wavebands have revealed significantly less cool gas than predicted indicating that the mass deposition rate of cooling flows is much lower than expected. However, most cooling flow clusters host an Active Galactic Nucleus (AGN) at their centres. AGN can inflate large bubbles of hot plasma that subsequently rise through the cluster atmosphere, thus stirring this gas. Here we report on the results from highly resolved hydrodynamic simulations which for the first time show that buoyant bubbles increase the cooling time in the inner cluster regions and thereby significantly reduce the deposition of cold gas. This work demonstrates that the action of AGN in the centres of cooling flow clusters can explain the obser...

  13. Metallographic anlaysis and strength investigation of different Be-Cu joints in the temperature range RT-3500C

    Energy Technology Data Exchange (ETDEWEB)

    Gervash, A.A.; Giniatouline, R.N.; Mazul, I.V. [Efremov Research Institute, St. Petersburg (Russian Federation)] [and others

    1995-09-01

    The goal of this work is to estimate the strength and structure of different Be-Cu joining techniques. Brazing, diffusion bonding and joint rolling methods were chosen as ITER Be-Cu joint method candidates. Selected for ITER application Be-Cu joints were produced as technological plates (30-50 mm x 50-100 mm x thickness). AR samples for farther investigations were cutted out from initial technological plates. To compare mechanical strength of selected Be-Cu joints tensile and shearing tests of chosen candidates were carried out in the temperature range RT - 350{degrees}C. The metallographic analysis of Be-Cu crosssection was also done. Preliminary results of these tests as well as metallographic analysis data are presented. The industrial possibilities of producing required for ITER full scale Be-Cu joints are discussed.

  14. On the influence of the alternation of two different cooling systems on dairy cow daily activities

    Directory of Open Access Journals (Sweden)

    Simona M.C. Porto

    2017-02-01

    Full Text Available Among the causes that influence cow welfare, heat stress induced by microclimatic conditions is one of the most relevant and many studies have investigated the efficacy of different cooling systems on animal health status. Nevertheless, the direct influence of the cooling systems on possible modifications of dairy cow behaviour has been addressed in a few studies and the related results were affected by the presence of a paddock, which gave a refuge from hot temperature. Since an alteration of the daily time budget spent by dairy cows in their usual activities can be associated with changes in their health status, this study investigated the effects of the alternation of two different cooling systems on lying, standing, and feeding behaviour of a group of dairy cows bred in a free-stall dairy house where animals had no access to a paddock. The barn was equipped with a fogging system associated with forced ventilation installed in the resting area and a sprinkler system associated with forced ventilation installed in the feeding area. The two systems were activated alternately. The results demonstrated that the management of the two cooling systems affected the analysed behaviours. Though the activation of the cooling system installed in the resting area encouraged the decubitus of animals in the stalls, the activation of that one of the feeding alley could not be able to influence the standing behaviour and had only a moderate positive influence on the feeding activity.

  15. First Detection of Linear Polarization in the Line Profiles of Active Cool Stars

    NARCIS (Netherlands)

    Kochukhov, O.; Makaganiuk, V.; Piskunov, N.; Snik, F.; Jeffers, S.V.; Johns-Krull, C. M.; Keller, C.U.; Rodenhuis, M.; Valenti, J. A.

    2011-01-01

    The application of high-resolution spectropolarimetry has led to major progress in understanding the magnetism and activity of late-type stars. During the last decade, magnetic fields have been discovered and mapped for many types of active cool stars using spectropolarimetric data. However, these o

  16. Calculation of Radioactivity and Dose Rate of Activated Corrosion Products in Water-Cooled Fusion Reactor

    Directory of Open Access Journals (Sweden)

    Jingyu Zhang

    2016-01-01

    Full Text Available In water-cooled reactor, the dominant radioactive source term under normal operation is activated corrosion products (ACPs, which have an important impact on reactor inspection and maintenance. A three-node transport model of ACPs was introduced into the new version of ACPs source term code CATE in this paper, which makes CATE capable of theoretically simulating the variation and the distribution of ACPs in a water-cooled reactor and suitable for more operating conditions. For code testing, MIT PWR coolant chemistry loop was simulated, and the calculation results from CATE are close to the experimental results from MIT, which means CATE is available and credible on ACPs analysis of water-cooled reactor. Then ACPs in the blanket cooling loop of water-cooled fusion reactor ITER under construction were analyzed using CATE and the results showed that the major contributors are the short-life nuclides, especially Mn-56. At last a point kernel integration code ARShield was coupled with CATE, and the dose rate around ITER blanket cooling loop was calculated. Results showed that after shutting down the reactor only for 8 days, the dose rate decreased nearly one order of magnitude, which was caused by the rapid decay of the short-life ACPs.

  17. Thermal design for areas of interference heating on actively cooled hypersonic aircraft

    Science.gov (United States)

    Herring, R. L.; Stone, J. E.

    1978-01-01

    Numerous actively cooled panel design alternatives for application in regions on high speed aircraft that are subject to interference heating effects were studied. Candidate design concepts were evaluated using mass, producibility, reliability and inspectability/maintainability as figures of merit. Three design approaches were identified as superior within certain regimes of the matrix of design heating conditions considered. Only minor modifications to basic actively cooled panel design are required to withstand minor interference heating effects. Designs incorporating internally finned coolant tubes to augment heat transfer are recommended for moderate design heating conditions. At severe heating conditions, an insulated panel concept is required.

  18. Performance evaluation of an active solar cooling system utilizing low cost plastic collectors and an evaporatively-cooled absorption chiller

    Science.gov (United States)

    Lof, G. O.; Westhoff, M. A.; Karaki, S.

    1984-02-01

    During the summer of 1982, air conditioning in Solar House 3 at Colorado State University was provided by an evaporatively-cooled absorption chiller. The single-effect lithium bromide chiller is an experimental three-ton unit from which heat is rejected by direct evaporative cooling of the condenser and absorber walls, thereby eliminating the need for a separate cooling tower. Domestic hot water was also provided by use of a double-walled heat exchanger and 80-gal hot water tank. A schematic of the system is given. Objectives of the project were: (1) evaluation of system performance over the course of one cooling season in Fort Collins, Colorado; (2) optimization of system operation and control; (3) development of a TRNSYS compatible model of the chiller; and (4) determination of cooling system performance in several U.S. climates by use of the model.

  19. Microelectromechanical System (MEMS) Device Being Developed for Active Cooling and Temperature Control

    Science.gov (United States)

    Beach, Duane E.

    2003-01-01

    High-capacity cooling options remain limited for many small-scale applications such as microelectronic components, miniature sensors, and microsystems. A microelectromechanical system (MEMS) using a Stirling thermodynamic cycle to provide cooling or heating directly to a thermally loaded surface is being developed at the NASA Glenn Research Center to meet this need. The device can be used strictly in the cooling mode or can be switched between cooling and heating modes in milliseconds for precise temperature control. Fabrication and assembly employ techniques routinely used in the semiconductor processing industry. Benefits of the MEMS cooler include scalability to fractions of a millimeter, modularity for increased capacity and staging to low temperatures, simple interfaces, limited failure modes, and minimal induced vibration. The MEMS cooler has potential applications across a broad range of industries such as the biomedical, computer, automotive, and aerospace industries. The basic capabilities it provides can be categorized into four key areas: 1) Extended environmental temperature range in harsh environments; 2) Lower operating temperatures for electronics and other components; 3) Precision spatial and temporal thermal control for temperature-sensitive devices; and 4) The enabling of microsystem devices that require active cooling and/or temperature control. The rapidly expanding capabilities of semiconductor processing in general, and microsystems packaging in particular, present a new opportunity to extend Stirling-cycle cooling to the MEMS domain. The comparatively high capacity and efficiency possible with a MEMS Stirling cooler provides a level of active cooling that is impossible at the microscale with current state-of-the-art techniques. The MEMS cooler technology builds on decades of research at Glenn on Stirling-cycle machines, and capitalizes on Glenn s emerging microsystems capabilities.

  20. Design and fabrication of a skin stringer discrete tube actively cooled structural panel

    Science.gov (United States)

    Anthony, F. M.

    1978-01-01

    The design optimization and practical implementation of actively cooled structural panel concepts was investigated. The desired actively cooled structural panel consisted of the cooled skin and a substructure. The primary load carrying components were fabricated from 2024-T3 aliminum alloy. The 3003-H14 coolant passage tubing was chosen because of its excellent corrosion resistance, workability needed to obtain the desired cross sectional shape, and strength. The Epon 951 adhesive was selected for its excellent structural properties and is the thinnest of available films, 0.064 mm. The Eccobond 58C silver filled epoxy was chosen because of its high thermal conductivity, and the alumina filled Epon 828 was chosen for structural and expansion characteristics.

  1. Innovative two-pipe active chilled beam system for simultaneous heating and cooling of office buildings

    DEFF Research Database (Denmark)

    Maccarini, Alessandro; Afshari, Alireza; Bergsøe, Niels Christian;

    2014-01-01

    energy between zones with one hydronic circuit, operating with a water temperature between 20°C and 23°C. To calculate the energy performance of the system, simulation-based research was developed. The two-pipe system was modelled by using EnergyPlus, a whole building energy simulation program. Hourly......The aim of this paper was to investigate the energy savings potential of an innovative two-pipe system in an active chilled beam application for heating and cooling of office buildings. The characteristic of the system is its ability to provide simultaneous heating and cooling by transferring...... heating, cooling and ventilation loads were calculated by the program and an annual energy consumption evaluation of the system was made. Simulation results showed that the innovative two-pipe active chilled beam system used approximately 5% less energy than a conventional four-pipe system....

  2. Active cooling in traumatic brain-injured patients: a questionable therapy?

    DEFF Research Database (Denmark)

    Grände, P-O; Reinstrup, P; Rommer, Bertil Roland

    2009-01-01

    Hypothermia is shown to be beneficial for the outcome after a transient global brain ischaemia through its neuroprotective effect. Whether this is also the case after focal ischaemia, such as following a severe traumatic brain injury (TBI), has been investigated in numerous studies, some of which......-quality trials are considered, TBI patients treated with active cooling were more likely to die, a conclusion supported by a recent high-quality Canadian trial on children. Still, there is a belief that a modified protocol with a shorter time from the accident to the start of active cooling, longer cooling...... and rewarming time and better control of blood pressure and intracranial pressure would be beneficial for TBI patients. This belief has led to the instigation of new trials in adults and in children, including these types of protocol adjustments. The present review provides a short summary of our present...

  3. Differences Between Passive And Active Cooling Systems In Gender, Physiological Responses, Thermal Sensation And Productivity

    DEFF Research Database (Denmark)

    Schellen, Lisje; Loomans, Marcel; van Marken Lichtenbelt, Wouter

    2011-01-01

    could occur due to application of low energy/exergy cooling systems, on human thermal comfort, physiological responses, and productivity. Furthermore, focus is on the differences between gender. This paper presents preliminary results obtained from experiments with four test subjects. To examine...... ventilation (To=26oC), active cooling by convection through (2) mixing and (3) displacement ventilation, active cooling by radiation (4) through the ceiling and mixing ventilation (5) through the floor and mixing ventilation and (6) through the floor and displacement ventilation. Three female subjects visited...... the climate room on two occasions: (1) and (4). During the experiments both physiological responses and thermal sensation were measured. To assess the productivity and performance a ‘Remote Performance Measurement’ (RPM) method was used....

  4. Venus Mobile Explorer with RPS for Active Cooling: A Feasibility Study

    Science.gov (United States)

    Leifer, Stephanie D.; Green, Jacklyn R.; Balint, Tibor S.; Manvi, Ram

    2009-01-01

    We present our findings from a study to evaluate the feasibility of a radioisotope power system (RPS) combined with active cooling to enable a long-duration Venus surface mission. On-board power with active cooling technology featured prominently in both the National Research Council's Decadal Survey and in the 2006 NASA Solar System Exploration Roadmap as mission-enabling for the exploration of Venus. Power and cooling system options were reviewed and the most promising concepts modeled to develop an assessment tool for Venus mission planners considering a variety of future potential missions to Venus, including a Venus Mobile Explorer (either a balloon or rover concept), a long-lived Venus static lander, or a Venus Geophysical Network. The concepts modeled were based on the integration of General Purpose Heat Source (GPHS) modules with different types of Stirling cycle heat engines for power and cooling. Unlike prior investigations which reported on single point design concepts, this assessment tool allows the user to generate either a point design or parametric curves of approximate power and cooling system mass, power level, and number of GPHS modules needed for a "black box" payload housed in a spherical pressure vessel.

  5. Rotation, activity, and lithium abundance in cool binary stars

    Science.gov (United States)

    Strassmeier, K. G.; Weber, M.; Granzer, T.; Järvinen, S.

    2012-10-01

    We have used two robotic telescopes to obtain time-series high-resolution optical echelle spectroscopy and V I and/or by photometry for a sample of 60 active stars, mostly binaries. Orbital solutions are presented for 26 double-lined systems and for 19 single-lined systems, seven of them for the first time but all of them with unprecedented phase coverage and accuracy. Eighteen systems turned out to be single stars. The total of 6609 {R=55 000} échelle spectra are also used to systematically determine effective temperatures, gravities, metallicities, rotational velocities, lithium abundances and absolute Hα-core fluxes as a function of time. The photometry is used to infer unspotted brightness, {V-I} and/or b-y colors, spot-induced brightness amplitudes and precise rotation periods. An extra 22 radial-velocity standard stars were monitored throughout the science observations and yield a new barycentric zero point for our STELLA/SES robotic system. Our data are complemented by literature data and are used to determine rotation-temperature-activity relations for active binary components. We also relate lithium abundance to rotation and surface temperature. We find that 74 % of all known rapidly-rotating active binary stars are synchronized and in circular orbits but 26 % (61 systems) are rotating asynchronously of which half have {P_rot>P_orb} and {e>0}. Because rotational synchronization is predicted to occur before orbital circularization active binaries should undergo an extra spin-down besides tidal dissipation. We suspect this to be due to a magnetically channeled wind with its subsequent braking torque. We find a steep increase of rotation period with decreasing effective temperature for active stars, P_rot ∝ T_eff-7, for both single and binaries, main sequence and evolved. For inactive, single giants with {P_rot>100} d, the relation is much weaker, {P_rot ∝ T_eff-1.12}. Our data also indicate a period-activity relation for Hα of the form {R_Hα ∝ P

  6. Feasibility of Actively Cooled Silicon Nitride Airfoil for Turbine Applications Demonstrated

    Science.gov (United States)

    Bhatt, Ramakrishna T.

    2001-01-01

    Nickel-base superalloys currently limit gas turbine engine performance. Active cooling has extended the temperature range of service of nickel-base superalloys in current gas turbine engines, but the margin for further improvement appears modest. Therefore, significant advancements in materials technology are needed to raise turbine inlet temperatures above 2400 F to increase engine specific thrust and operating efficiency. Because of their low density and high-temperature strength and thermal conductivity, in situ toughened silicon nitride ceramics have received a great deal of attention for cooled structures. However, the high processing costs and low impact resistance of silicon nitride ceramics have proven to be major obstacles for widespread applications. Advanced rapid prototyping technology in combination with conventional gel casting and sintering can reduce high processing costs and may offer an affordable manufacturing approach. Researchers at the NASA Glenn Research Center, in cooperation with a local university and an aerospace company, are developing actively cooled and functionally graded ceramic structures. The objective of this program is to develop cost-effective manufacturing technology and experimental and analytical capabilities for environmentally stable, aerodynamically efficient, foreign-object-damage-resistant, in situ toughened silicon nitride turbine nozzle vanes, and to test these vanes under simulated engine conditions. Starting with computer aided design (CAD) files of an airfoil and a flat plate with internal cooling passages, the permanent and removable mold components for gel casting ceramic slips were made by stereolithography and Sanders machines, respectively. The gel-cast part was dried and sintered to final shape. Several in situ toughened silicon nitride generic airfoils with internal cooling passages have been fabricated. The uncoated and thermal barrier coated airfoils and flat plates were burner rig tested for 30 min without

  7. Spots, activity cycles, and differential rotation on cool stars

    Science.gov (United States)

    Alekseev, I. Yu.

    2005-01-01

    The first results are reported from a search for activity cycles in stars similar to the sun based on modelling their spotting with an algorithm developed at the Crimean Astrophysical Observatory. Of the more than thirty program stars, 10 manifested a cyclical variation in their central latitudes and total starspot area. The observed cycles have durations of 4-15 years, i.e., analogous to the 11 year Schwabe sunspot cycle. Most of the stars have a rough analog of the solar butterfly pattern, with a reduction in the average latitude of the spots as their area increases. A flip-flop effect during the epoch of the maximum average latitude is noted in a number of these objects (e.g., the analog LQ Hya of the young sun or the RS CVn-type variable V711 Tau), as well as a reduction in the photometric rotation period of a star as the spots drift toward the equator, an analog of the differential rotation effect in the sun. Unlike in the sun, the observed spot formation cycles do not correlate uniquely with other indicators of activity— chromospheric emission in the CaII HK lines (Be Cet, EK Dra, Dx Leo), H line emission (LQ Hya, VY Ari, EV Lac), or cyclical flare activity (EV Lac). In V833 Tau, BY Dra, EK Dra, and VY Ari short Schwabe cycles coexist with long cycles that are analogous to the Gleissberg solar cycle, in which the spotted area can approach half the entire area of the star.

  8. First detection of linear polarization in the line profiles of active cool stars

    CERN Document Server

    Kochukhov, O; Piskunov, N; Snik, F; Jeffers, S V; Johns-Krull, C M; Keller, C U; Rodenhuis, M; Valenti, J A

    2011-01-01

    The application of high-resolution spectropolarimetry has led to major progress in understanding the magnetism and activity of late-type stars. During the last decade, magnetic fields have been discovered and mapped for many types of active cool stars using spectropolarimetric data. However, these observations and modeling attempts are fundamentally incomplete since they are based on the interpretation of the circular polarization alone. Taking advantage of the newly built HARPS polarimeter, we have obtained the first systematic observations of several cool active stars in all four Stokes parameters. Here we report the detection of magnetically-induced linear polarization for the primary component of the very active RS CVn binary HR 1099 and for the moderately active K dwarf epsilon Eri. For both stars the amplitude of linear polarization signatures is measured to be ~10^{-4} of the unpolarized continuum, which is approximately a factor of ten lower than for circular polarization. This is the first detection ...

  9. Deactivation of the inferior colliculus by cooling demonstrates intercollicular modulation of neuronal activity

    Directory of Open Access Journals (Sweden)

    Llwyd David Orton

    2012-12-01

    Full Text Available The auditory pathways coursing through the brainstem are organised bilaterally in mirror image about the midline and at several levels the two sides are interconnected. One of the most prominent points of interconnection is the commissure of the inferior colliculus (CoIC. Anatomical studies have revealed that these fibres make reciprocal connections which follow the tonotopic organisation of the inferior colliculus (IC, and that the commissure contains both excitatory and, albeit fewer, inhibitory fibres. The role of these connections in sound processing is largely unknown. Here we describe a method to address this question in the anaesthetised guinea pig. We used a cryoloop placed on one IC to produce reversible deactivation while recording electrophysiological responses to sounds in both ICs. We recorded single units, multi-unit clusters and local field potentials (LFPs before, during and after cooling. The degree and spread of cooling was measured with a thermocouple placed in the IC and other auditory structures. Cooling sufficient to eliminate firing was restricted to the IC contacted by the cryoloop. The temperature of other auditory brainstem structures, including the contralateral IC and the cochlea were minimally affected. Cooling below 20 °C reduced or eliminated the firing of action potentials in frequency laminae at depths corresponding to characteristic frequencies up to ~8 kHz. Modulation of neural activity also occurred in the un-cooled IC with changes in single unit firing and LFPs. Components of LFPs signalling lemniscal afferent input to the IC showed little change in amplitude or latency with cooling, whereas the later components, which likely reflect inter- and intra-collicular processing, showed marked changes in form and amplitude. We conclude that the cryoloop is an effective method of selectively deactivating one IC in guinea pig, and demonstrate that auditory processing in the IC is strongly influenced by the other.

  10. Investigation of Be/Cu joints via HHF tests of small-scale mockups

    Energy Technology Data Exchange (ETDEWEB)

    Giniatulin, R.; Gervash, A.; Komarov, V.L.; Litunovsky, N.; Mazul, I.; Yablokov, N. [Efremov Inst., St. Petersburg (Russian Federation)

    1998-01-01

    Beryllium-copper (Be/Cu) joints in divertor components work under cyclic heat loads. To develop reliable joints small-scale mockups are fabricated by divertor technologies and tested under the divertor conditions. One of the critical damaging factors that exist in the divertor and have to be simulated is thermocyclic heat loads in the range of 1-15 MW/m{sup 2}. This work presents the divertor mockups that have beryllium tiles with different dimensions (5 x 5 - 44 x 44) mm{sup 2} brazed with copper alloy heat sink. The electron beam was used to braze these mockups so as to decrease the formation of brittle intermetallic layers. The description of mockups design, geometry of armour tiles and fabrication techniques are presented in the paper. The results of screening and thermocyclic tests of these mockups in the heat flux range of 2-12 MW/m{sup 2} with a number of cycles {approx}10{sup 3} are presented. The results of metallographic analysis are also presented. The results of fabrication and testing with small-scale mockups for first wall application are also described. (author)

  11. Active Cooling and Thermal Management of a Downhole Tool Electronics Section

    DEFF Research Database (Denmark)

    Soprani, Stefano; Engelbrecht, Kurt; Just Nørgaard, Anders

    2015-01-01

    High Temperature (HT) wellbores represent one of today’s biggest challenges for the oil and gas industry. The majority of well intervention wireline tools contain temperature sensitive electronics that are not able to withstand the high temperatures of HT wellbores (> 150 °C), for an extended...... period of time. This work presents the design and construction of an actively cooled laboratory prototype, which is able to operate at temperatures which are higher than the temperature limit of the electronics. A different concept of heat management, compared to prior works, is presented: the design...... combines active and passive cooling techniques, aiming at an efficient thermal management, preserving the tool compactness and avoiding the use of moving parts. Thermoelectric coolers were used to transfer the dissipated heat from the temperature-sensitive electronics to the external environment. Thermal...

  12. Analytic estimation and numerical modeling of actively cooled thermal protection systems with nickel alloys

    Institute of Scientific and Technical Information of China (English)

    Wang Xinzhi; He Yurong; Zheng Yan; Ma Junju; H. Inaki Schlaberg

    2014-01-01

    Actively cooled thermal protection system has great influence on the engine of a hyper-sonic vehicle, and it is significant to obtain the thermal and stress distribution in the system. So an analytic estimation and numerical modeling are performed in this paper to investigate the behavior of an actively cooled thermal protection system. The analytic estimation is based on the electric analogy method and finite element analysis (FEA) is applied to the numerical simulation. Temper-ature and stress distributions are obtained for the actively cooled channel walls with three kinds of nickel alloys with or with no thermal barrier coating (TBC). The temperature of the channel wall with coating has no obvious difference from the one with no coating, but the stress with coating on the channel wall is much smaller than that with no coating. Inconel X-750 has the best charac-teristics among the three Ni-based materials due to its higher thermal conductivity, lower elasticity module and greater allowable stress. Analytic estimation and numerical modeling results are com-pared with each other and a reasonable agreement is obtained.

  13. Analytic estimation and numerical modeling of actively cooled thermal protection systems with nickel alloys

    Directory of Open Access Journals (Sweden)

    Wang Xinzhi

    2014-12-01

    Full Text Available Actively cooled thermal protection system has great influence on the engine of a hypersonic vehicle, and it is significant to obtain the thermal and stress distribution in the system. So an analytic estimation and numerical modeling are performed in this paper to investigate the behavior of an actively cooled thermal protection system. The analytic estimation is based on the electric analogy method and finite element analysis (FEA is applied to the numerical simulation. Temperature and stress distributions are obtained for the actively cooled channel walls with three kinds of nickel alloys with or with no thermal barrier coating (TBC. The temperature of the channel wall with coating has no obvious difference from the one with no coating, but the stress with coating on the channel wall is much smaller than that with no coating. Inconel X-750 has the best characteristics among the three Ni-based materials due to its higher thermal conductivity, lower elasticity module and greater allowable stress. Analytic estimation and numerical modeling results are compared with each other and a reasonable agreement is obtained.

  14. Rapid cooling rates at an active mid-ocean ridge from zircon thermochronology

    Science.gov (United States)

    Schmitt, Axel K.; Perfit, Michael R.; Rubin, Kenneth H.; Stockli, Daniel F.; Smith, Matthew C.; Cotsonika, Laurie A.; Zellmer, Georg F.; Ridley, W. Ian

    2011-01-01

    Oceanic spreading ridges are Earth's most productive crust generating environment, but mechanisms and rates of crustal accretion and heat loss are debated. Existing observations on cooling rates are ambiguous regarding the prevalence of conductive vs. convective cooling of lower oceanic crust. Here, we report the discovery and dating of zircon in mid-ocean ridge dacite lavas that constrain magmatic differentiation and cooling rates at an active spreading center. Dacitic lavas erupted on the southern Cleft segment of the Juan de Fuca ridge, an intermediate-rate spreading center, near the intersection with the Blanco transform fault. Their U–Th zircon crystallization ages (29.3-4.6+4.8 ka; 1δ standard error s.e.) overlap with the (U–Th)/He zircon eruption age (32.7 ± 1.6 ka) within uncertainty. Based on similar 238U-230Th disequilibria between southern Cleft dacite glass separates and young mid-ocean ridge basalt (MORB) erupted nearby, differentiation must have occurred rapidly, within ~ 10–20 ka at most. Ti-in-zircon thermometry indicates crystallization at 850–900 °C and pressures > 70–150 MPa are calculated from H2O solubility models. These time-temperature constraints translate into a magma cooling rate of ~ 2 × 10-2 °C/a. This rate is at least one order-of-magnitude faster than those calculated for zircon-bearing plutonic rocks from slow spreading ridges. Such short intervals for differentiation and cooling can only be resolved through uranium-series (238U–230Th) decay in young lavas, and are best explained by dissipating heat convectively at high crustal permeability.

  15. Resistance of Alkali Activated Water-Cooled Slag Geopolymer to Sulphate Attack

    Directory of Open Access Journals (Sweden)

    S. A. Hasanein

    2011-06-01

    Full Text Available Ground granulated blast furnace slag is a finely ground, rapidly chilled aluminosilicate melt material that is separated from molten iron in the blast furnace as a by-product. Rapid cooling results in an amorphous or a glassy phase known as GGBFS or water cooled slag (WCS. Alkaline activation of latent hydraulic WCS by sodium hydroxide and/or sodium silicate in different ratios was studied. Curing was performed under 100 % relative humidity and at a temperature of 38°C. The results showed that mixing of both sodium hydroxide and sodium silicate in ratio of 3:3 wt.,% is the optimum one giving better mechanical as well as microstructural characteristics as compared with cement mortar that has various cement content (cement : sand were 1:3 and 1:2. Durability of the water cooled slag in 5 % MgSO4 as revealed by better microstructure and high resistivity-clarifying that activation by 3:3 sodium hydroxide and sodium silicate, respectively is better than using 2 and 6 % of sodium hydroxide.

  16. Experimental investigation on activated carbon-ethanol pair for solar powered adsorption cooling applications

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawy, I.I. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen 6-1, Kasuga-shi, Fukuoka 816-8580 (Japan); Mechanical Power Engineering Department, Faculty of Engineering, Mansoura University, El-Mansoura (Egypt); Saha, B.B.; Koyama, S. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen 6-1, Kasuga-shi, Fukuoka 816-8580 (Japan); He, J.; Ng, K.C.; Yap, C. [Department of Mechanical Engineering, National University of Singapore, 10 Kent Ridge Crescent (Singapore)

    2008-12-15

    Adsorption equilibrium uptake of ethanol onto a highly porous activated carbon based adsorbent, namely Maxsorb III, has been experimentally investigated using a thermo-gravimetric analyzer (TGA) unit over adsorption temperatures ranging from 20 to 60 C. The Dubinin-Astakhov (D-A) equation has been used to correlate the experimental data. Isosteric heat of adsorption is also estimated by using the Clausius-Clapeyron equation. Employing a thermodynamically equilibrium model, the performance of the ideal adsorption cooling cycle has also been studied and compared to that of activated carbon fiber (ACF)-ethanol pair. Experimental results show that Maxsorb III can adsorb up to 1.2 kg of ethanol per kilogram of adsorbent. Theoretical calculations show that, the Maxsorb III-ethanol adsorption cycle can achieve a specific cooling effect of about 420 kJ kg{sup -1} at an evaporator temperature of 7 C along with a heat source of temperature 80 C and thus the pair is recommended for solar cooling applications. (author)

  17. Micro free-flow IEF enhanced by active cooling and functionalized gels.

    Science.gov (United States)

    Albrecht, Jacob W; Jensen, Klavs F

    2006-12-01

    Rapid free-flow IEF is achieved in a microfluidic device by separating the electrodes from the focusing region with porous buffer regions. Moving the electrodes outside enables the use of large electric fields without the detrimental effects of bubble formation in the active region. The anode and cathode porous buffer regions, which are formed by acrylamide functionalized with immobilized pH groups, allow ion transport while providing buffering capacity. Thermoelectric cooling mitigates the effects of Joule heating on sample focusing at high field strengths (approximately 500 V/cm). This localized cooling was observed to increase device performance. Rapid focusing of low-molecular-weight p/ markers and Protein G-mouse IgG complexes demonstrate the versatility of the technique. Simulations provide insight into and predict device performance based on a well-defined sample composition.

  18. Evaluation of a large capacity heat pump concept for active cooling of hypersonic aircraft structure

    Science.gov (United States)

    Pagel, L. L.; Herring, R. L.

    1978-01-01

    Results of engineering analyses assessing the conceptual feasibility of a large capacity heat pump for enhancing active cooling of hypersonic aircraft structure are presented. A unique heat pump arrangement which permits cooling the structure of a Mach 6 transport to aluminum temperatures without the aid of thermal shielding is described. The selected concept is compatible with the use of conventional refrigerants, with Freon R-11 selected as the preferred refrigerant. Condenser temperatures were limited to levels compatible with the use of conventional refrigerants by incorporating a unique multipass condenser design, which extracts mechanical energy from the hydrogen fuel, prior to each subsequent pass through the condenser. Results show that it is technically feasible to use a large capacity heat pump in lieu of external shielding. Additional analyses are required to optimally apply this concept.

  19. Activation analyses for the Korea helium cooled ceramic reflector test blanket module

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheol Woo, E-mail: cwl@kaeri.re.kr [Korea Atomic Energy Research Institute, 989 Daeduck-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Young-Ouk [Korea Atomic Energy Research Institute, 989 Daeduck-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ahn, Mu-Young; Cho, Seungyon [National Fusion Research Institute, Gwahangno, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Lee, Dong Won [Korea Atomic Energy Research Institute, 989 Daeduck-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2013-10-15

    The activation analyses were performed to obtain activities, inventories and dose rates after shutdown for the Korea HCCR TBM. MonteBurns code coupled with MCNP and CINDER codes was used in the activation calculation and the irradiation history based on the SA2 scenario was applied. The total activity in TBM after shutdown was evaluated as a value of 4.12 × 10{sup 16} Bq. Dose rates after shutdown from the activated HCCR TBM was estimated. The decay gamma-ray spectra in each region inside TBM were estimated based on the calculated activities. The dose rate at 0 cm–3 m from the FW surface of HCCR TBM was evaluated according to the cooling time of 1 day, 1 week, 1 month, 6 months and 1 year. The dose rate at 0 cm from the FW surface was evaluated to be 575.84 Sv/h at 1 day after shutdown.

  20. Experimental investigations on active cooling thermal protection structure of hydrocarbon-fueled scramjet combustor in arc heated facility

    Science.gov (United States)

    Jianqiang, Tu; Jinlong, Peng; Xianning, Yang; Lianzhong, Chen

    2016-10-01

    The active cooling thermal protection technology is the efficient method to resolve the long-duration work and reusable problems of hydrocarbon-fueled scramjet combustor, where worst thermo-mechanical loads occur. The fuel is passed through coolant channels adjacent to the heated surfaces to absorb heat from the heating exchanger panels, prior to injection into the combustor. The heating exchanger both cooled down the wall temperature of the combustor wall and heats and cracks the hydrocarbon fuel inside the panel to permit an easier combustion and satisfying combustion efficiency. The subscale active cooling metallic panels, with dimensions of 100×100 mm and different coolant channel sizes, have been tested under typical combustion thermal environment produced by arc heated Turbulent Flow Duct (TFD). The heat exchange ability of different coolant channel sizes has been obtained. The big-scale active cooling metallic panel, with dimensions of 100 × 750 mm and the coolant channel sizes of better heating exchange performance, has been made and tested in the big-scale arc heated TFD facility. The test results show that the local superheated ablation is easy to happen for the cooling fuel assigned asymmetrically in the bigscale active cooling metallic panel, and the cooling fuel rate can reduce 8%˜10% after spraying the Thermal Barrier Coating (TBC) in the heating surface.

  1. Cooling vest worn during active warm-up improves 5-km run performance in the heat.

    Science.gov (United States)

    Arngrïmsson, Sigurbjörn A; Petitt, Darby S; Stueck, Matthew G; Jorgensen, Dennis K; Cureton, Kirk J

    2004-05-01

    We investigated whether a cooling vest worn during an active warm-up enhances 5-km run time in the heat. Seventeen competitive runners (9 men, maximal oxygen uptake = 66.7 +/- 5.9 ml x kg(-1) x min(-1); 8 women, maximal oxygen uptake = 58.0 +/- 3.2 ml x kg(-1) x min(-1)) completed two simulated 5-km runs on a treadmill after a 38-min active warm-up during which they wore either a T-shirt (C) or a vest filled with ice (V) in a hot, humid environment (32 degrees C, 50% relative humidity). Wearing the cooling vest during warm-up significantly (P run, esophageal, rectal, mean skin, and mean body temperatures averaged 0.3, 0.2, 1.8, and 0.4 degrees C lower; HR averaged 11 beats/min lower; and perception of thermal discomfort (5-point scale) averaged 0.6 point lower in V than C. Most of these differences were eliminated during the first 3.2 km of the run, and these variables were not different at the end. The 5-km run time was significantly lower (P faster pace most evident during the last two-thirds of the run. We conclude that a cooling vest worn during active warm-up by track athletes enhances 5-km run performance in the heat. Reduced thermal and cardiovascular strain and perception of thermal discomfort in the early portion of the run appear to permit a faster pace later in the run.

  2. A nonventing cooling system for space environment extravehicular activity, using radiation and regenerable thermal storage

    Science.gov (United States)

    Bayes, Stephen A.; Trevino, Luis A.; Dinsmore, Craig E.

    1988-01-01

    This paper outlines the selection, design, and testing of a prototype nonventing regenerable astronaut cooling system for extravehicular activity space suit applications, for mission durations of four hours or greater. The selected system consists of the following key elements: a radiator assembly which serves as the exterior shell of the portable life support subsystem backpack; a layer of phase change thermal storage material, n-hexadecane paraffin, which acts as a regenerable thermal capacitor; a thermoelectric heat pump; and an automatic temperature control system. The capability for regeneration of thermal storage capacity with and without the aid of electric power is provided.

  3. Synthesis of some novel sulfonamide derivatives and investigating their biocidal activity in cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Badawi, Abdelfattah M.; Mohamed, Dalia Emam; Hafiz, Amal A.; Amed, Sahar M. [Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt). Applied Surfactants Lab.; Gohar, Yousry M. [Alexandria Univ. (Egypt). Microbiology Div.; Soliman, El-Sayed Ahmed [Ain Shams Univ., Cairo (Egypt). Chemistry Dept.; Sanan, Mohamed S. [Alexandria National Refining and Petrochemical Co. (ANRPC), Alexandria (Egypt)

    2011-03-15

    A novel series of dibenzothiophenedioxide sulphonamide derivatives were synthesized and tested as antimicrobial agents. The chemical structures of the prepared compounds were confirmed by micro elemental analysis, fourier transform infrared (FT-IR) and proton nuclear magnetic resonance spectroscopy (H-NMR). The surface parameters of two of the prepared compounds were determined at 35 C including, surface tension, effectiveness, maximum surface excess and minimum surface area. Also the standard free energy of micellization and adsorption were recorded. The results showed that the prepared sulphonamides have good surface properties and effective antimicrobial activity against thirty three test organisms isolated from cooling towers. (orig.)

  4. Magnetocaloric Properties of Fe-Ni-Cr Nanoparticles for Active Cooling.

    Science.gov (United States)

    Chaudhary, V; Ramanujan, R V

    2016-10-11

    Low cost, earth abundant, rare earth free magnetocaloric nanoparticles have attracted an enormous amount of attention for green, energy efficient, active near room temperature thermal management. Hence, we investigated the magnetocaloric properties of transition metal based (Fe70Ni30)100-xCrx (x = 1, 3, 5, 6 and 7) nanoparticles. The influence of Cr additions on the Curie temperature (TC) was studied. Only 5% of Cr can reduce the TC from ~438 K to 258 K. These alloys exhibit broad entropy v/s temperature curves, which is useful to enhance relative cooling power (RCP). For a field change of 5 T, the RCP for (Fe70Ni30)99Cr1 nanoparticles was found to be 548 J-kg(-1). Tunable TCin broad range, good RCP, low cost, high corrosion resistance and earth abundance make these nanoparticles suitable for low-grade waste heat recovery as well as near room temperature active cooling applications.

  5. High heat flux actively cooled plasma facing components development, realization and first results in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Grosman, A. [Association Euratom-CEA, Centre d' Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2004-07-01

    The development, design, manufacture and testing of actively cooled high heat flux plasma facing components (PFC) has been an essential stage towards long powerful tokamak operations for Tore-Supra, it lasted about 10 years. This paper deals with the toroidal pumped limiter (TPL) that is able to sustain up to 10 MW/m{sup 2} of nominal heat flux. This device is based on hardened copper alloy heat sink structures covered by a carbon fiber composite armour, it resulted in the manufacturing of 600 elementary components, called finger elements, to achieve the 7.6 m{sup 2} TPL. This assembly has been operating in Tore-Supra since spring 2002. Some difficulties occurred during the manufacturing phase, the valuable industrial experience is summarized in the section 2. The permanent monitoring of PFC surface temperature all along the discharge is performed by a set of 6 actively cooled infrared endoscopes. The heat flux monitoring and control issue but also the progress made in our understanding of the deuterium retention in long discharges are described in the section 3. (A.C.)

  6. Firefighter feedback during active cooling: a useful tool for heat stress management?

    Science.gov (United States)

    Savage, Robbie J; Lord, Cara; Larsen, Brianna L; Knight, Teagan L; Langridge, Peter D; Aisbett, Brad

    2014-12-01

    Monitoring an individual's thermic state in the workplace requires reliable feedback of their core temperature. However, core temperature measurement technology is expensive, invasive and often impractical in operational environments, warranting investigation of surrogate measures which could be used to predict core temperature. This study examines an alternative measure of an individual's thermic state, thermal sensation, which presents a more manageable and practical solution for Australian firefighters operating on the fireground. Across three environmental conditions (cold, warm, hot & humid), 49 Australian volunteer firefighters performed a 20-min fire suppression activity, immediately followed by 20 min of active cooling using hand and forearm immersion techniques. Core temperature (Tc) and thermal sensation (TS) were measured across the rehabilitation period at five minute intervals. Despite the decline in Tc and TS throughout the rehabilitation period, there was little similarity in the magnitude or rate of decline between each measure in any of the ambient conditions. Moderate to strong correlations existed between Tc and TS in the cool (0.41, pheat stress management.

  7. Magnetocaloric Properties of Fe-Ni-Cr Nanoparticles for Active Cooling

    Science.gov (United States)

    Chaudhary, V.; Ramanujan, R. V.

    2016-10-01

    Low cost, earth abundant, rare earth free magnetocaloric nanoparticles have attracted an enormous amount of attention for green, energy efficient, active near room temperature thermal management. Hence, we investigated the magnetocaloric properties of transition metal based (Fe70Ni30)100‑xCrx (x = 1, 3, 5, 6 and 7) nanoparticles. The influence of Cr additions on the Curie temperature (TC) was studied. Only 5% of Cr can reduce the TC from ~438 K to 258 K. These alloys exhibit broad entropy v/s temperature curves, which is useful to enhance relative cooling power (RCP). For a field change of 5 T, the RCP for (Fe70Ni30)99Cr1 nanoparticles was found to be 548 J-kg‑1. Tunable TCin broad range, good RCP, low cost, high corrosion resistance and earth abundance make these nanoparticles suitable for low-grade waste heat recovery as well as near room temperature active cooling applications.

  8. A Novel Cooling Method and Comparison of Active Rewarming of Mildly Hypothermic Subjects.

    Science.gov (United States)

    Christensen, Mark L; Lipman, Grant S; Grahn, Dennis A; Shea, Kate M; Einhorn, Joseph; Heller, H Craig

    2017-06-01

    To compare the effectiveness of arteriovenous anastomosis (AVA) vs heated intravenous fluid (IVF) rewarming in hypothermic subjects. Additionally, we sought to develop a novel method of hypothermia induction. Eight subjects underwent 3 cooling trials each to a core temperature of 34.8±0.6 (32.7 to 36.3°C [mean±SD with range]) by 14°C water immersion for 30 minutes, followed by walking on a treadmill for 5 minutes. Core temperatures (Δtes) and rates of cooling (°C/h) were measured. Participants were then rewarmed by 1) control: shivering only in a sleeping bag; 2) IVF: shivering in sleeping bag and infusion of 2 L normal saline warmed to 42°C at 77 mL/min; and 3) AVA: shivering in sleeping bag and circulation of 45°C warmed fluid through neoprene pads affixed to the palms and soles of the feet. Cold water immersion resulted in a decrease of 0.5±0.5°C Δtes and 1±0.3°C with exercise (P benefit in either of the 2 active rewarming methods, AVA rewarming showed a nonsignificant trend toward greater shivering inhibition, which may be optimized by an improved interface. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  9. Experiments on FTU with an actively water cooled liquid lithium limiter

    Energy Technology Data Exchange (ETDEWEB)

    Mazzitelli, G., E-mail: giuseppe.mazzitelli@enea.it [Associazione EURATOM-ENEA sulla Fusione, C.R. Frascati, C.P. 65-00044 Frascati, Rome (Italy); Apicella, M.L.; Apruzzese, G.; Crescenzi, F.; Iannone, F.; Maddaluno, G. [Associazione EURATOM-ENEA sulla Fusione, C.R. Frascati, C.P. 65-00044 Frascati, Rome (Italy); Pericoli-Ridolfini, V. [Associazione EURATOM-ENEA sulla Fusione, CREATE, Università di Napoli Federico II, 80125 Napoli (Italy); Roccella, S.; Reale, M.; Viola, B. [Associazione EURATOM-ENEA sulla Fusione, C.R. Frascati, C.P. 65-00044 Frascati, Rome (Italy); Lyublinski, I.; Vertkov, A. [JSC “RED STAR”, Moscow (Russian Federation)

    2015-08-15

    In order to prevent the overheating of the liquid Li surface and the consequent Li evaporation for T > 500 °C, an advanced version of the liquid lithium limiter has been realized and installed on FTU. This new system, named Cooled Lithium Limiter (CLL), has been optimized to demonstrate the lithium limiter capability to sustain thermal loads as high as 10 MW/m{sup 2} with up to 5 s of plasma pulse duration. The CLL operates with an actively cooled system with water circulation at the temperature of about 200 °C, for heating lithium up to the melting point and for the heat removal during the plasma discharges. To characterize CLL during discharges, a fast infrared camera and the spectroscopic signals from Li and D atom emission have been used. The experiments analyzed so far and simulated by ANSYS code, point out that heat loads as high as 2 MW/m{sup 2} for 1.5 s have been withstood without problems.

  10. Experimental and Numerical Study of the Effects of Acoustic Sound Absorbers on the Cooling Performance of Thermally Active Building Systems

    DEFF Research Database (Denmark)

    Domínguez, L. Marcos; Kazanci, Ongun Berk; Rage, Nils

    2017-01-01

    Free-hanging horizontal and vertical sound absorbers are commonly used in buildings for room acoustic control; however, when these sound absorbers are used in combination with Thermally Active Building Systems, they will decrease the cooling performance of Thermally Active Building Systems...... plug-in for acoustic elements, which allows modeling free-hanging horizontal sound absorbers that partially cover the ceiling. With horizontal sound absorbers, the cooling performance of the Thermally Active Building System decreased by 11%, 23% and 36% for ceiling coverage ratios of 43%, 60% and 80...... and this will affect the thermal indoor environment in that space. Therefore, it is crucial to be able to quantify and model these effects in the design phase. This study quantifies experimentally the effects of horizontal and vertical free-hanging sound absorbers on the cooling performance of Thermally Active...

  11. A totally active scintillator calorimeter for the Muon Ionization Cooling Experiment (MICE). Design and construction

    CERN Document Server

    Asfandiyarov, R

    2013-01-01

    The Electron-Muon Ranger (EMR) is a totally active scintillator detector to be installed in the muon beam of the Muon Ionization Cooling Experiment (MICE) [1] – the main R&D project for the future neutrino factory. It is aimed at measuring the properties of the low energy beam composed of muons, electrons and pions, performing the identification particle by particle. The EMR is made of 48 stacked layers alternately measuring the X- and the Y-coordinate. Each layer consists of 59 triangular scintillator bars. It is shown that the granularity of the detector permits to identify tracks and to measure particle ranges and shower shapes. The read-out is based on FPGA custom made electronics and commercially available modules. Currently it is being built at the University of Geneva.

  12. Active cooling of pulse compression diffraction gratings for high energy, high average power ultrafast lasers.

    Science.gov (United States)

    Alessi, David A; Rosso, Paul A; Nguyen, Hoang T; Aasen, Michael D; Britten, Jerald A; Haefner, Constantin

    2016-12-26

    Laser energy absorption and subsequent heat removal from diffraction gratings in chirped pulse compressors poses a significant challenge in high repetition rate, high peak power laser development. In order to understand the average power limitations, we have modeled the time-resolved thermo-mechanical properties of current and advanced diffraction gratings. We have also developed and demonstrated a technique of actively cooling Petawatt scale, gold compressor gratings to operate at 600W of average power - a 15x increase over the highest average power petawatt laser currently in operation. Combining this technique with low absorption multilayer dielectric gratings developed in our group would enable pulse compressors for petawatt peak power lasers operating at average powers well above 40kW.

  13. Design and Analysis of Phase Change Material based thermal energy storage for active building cooling: a Review

    Directory of Open Access Journals (Sweden)

    Nitin .D. Patil

    2012-06-01

    Full Text Available Phase Change Materials (PCMs are "latent" thermal storage materials. They use chemical bonds to store and release heat. The thermal energy transfer occurs when a material changes from a solid to a liquid orfrom a liquid to a solid form. This is called a change in state or "phase." Initially, these solid-liquid PCMs perform like conventional storage materials; their temperature rises as they absorb solar heat. Unlike conventional heat storage materials, when PCMs reach the temperature at which they change phase (their melting point, they absorb large amounts of heat without getting hotter. When the ambient temperature in the space around the PCM material drops, the Phase Change Material solidifies, releasing its stored latent heat. PCMs absorb and emit heat while maintaining a nearly constant temperature. Within the human comfort and electronic-equipment tolerance range of 20°C to 35°C, latent thermal storage materials are very effective.They can be used for equalization of day & night temperature and for transport of refrigerated products. In the proposed project heat of fusion of Cacl2. 6H2o as PCM is used for cooling water during night and this cooled water is used as circulating medium trough fan coil unit, air trough FCU will get cooled by transferring heat to water and fresh & cool air will be thrown in a room. In the proposed project FREE COOLING & ACTIVE BUILDING COOLING concepts of Thermal Energy Storage are used in combine

  14. Tractor Mechanics. Maintaining and Servicing the Cooling System, Learning Activity Packages 34-40; Maintaining and Servicing Hydraulic Systems, Learning Activity Packages 41-48.

    Science.gov (United States)

    Clemson Univ., SC. Vocational Education Media Center.

    This series of learning activity packages focuses on two areas of tractor mechanics: (1) maintaining and servicing the cooling system and (2) maintaining and servicing hydraulic systems. Each of the fifteen illustrated learning activity packages follows a typical format: introduction, directions, objectives, learning activities, tools and…

  15. Thermo Active Building Systems Using Building Mass To Heat and Cool

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2012-01-01

    Using the thermal storage capacity of the concrete slabs between each floor in multistory buildings to heat or cool is a trend that began in the early 1990s in Switzerland.1,2 Pipes carrying water for heating and cooling are embedded in the center of the concrete slab. In central Europe (Germany...

  16. Investigating Active Accretion, Flare Activity and a 50 Million Degree Corona in the cool AGB Star, Y Gem

    Science.gov (United States)

    Sahai, Raghvendra

    2014-09-01

    We propose to make multi-epoch observations of the X-ray (and radio contiuum) emission from a cool AGB star, Y Gem. This star shows relatively strong X-ray emission implying the presence of 50 million degree coronal gas, and highly-variable FUV and NUV fluxes - likely evidence of variable accretion onto a magnetized accretion disk in a binary system. Y Gem is the most prominent member of a new class of AGB stars with FUV excesses identified using the GALEX archive. Our study will allow us to study the never-before explored phase of an active accretion disk in an AGB star with a binary companion. Such disks are believed to ultimately produce collimated jets that transform AGB circumsetllar envelopes into bipolar planetary nebulae.

  17. A relationship between halo mass, cooling, active galactic nuclei heating and the co-evolution of massive black holes

    Science.gov (United States)

    Main, R. A.; McNamara, B. R.; Nulsen, P. E. J.; Russell, H. R.; Vantyghem, A. N.

    2017-02-01

    We derive X-ray mass, luminosity, and temperature profiles for 45 galaxy clusters to explore relationships between halo mass, active galactic nuclei (AGN) feedback, and central cooling time. We find that radio-mechanical feedback power (referred to here as `AGN power') in central cluster galaxies correlates with halo mass as Pmech ∝ M1.55 ± 0.26, but only in haloes with central atmospheric cooling times shorter than 1 Gyr. The trend of AGN power with halo mass is consistent with the scaling expected from a self-regulating AGN feedback loop, as well as with galaxy and central black hole co-evolution along the MBH-σ relation. AGN power in clusters with central atmospheric cooling times longer than ˜1 Gyr typically lies two orders of magnitude below those with shorter central cooling times. Galaxies centred in clusters with long central cooling times nevertheless experience ongoing and occasionally powerful AGN outbursts. We further investigate the impact of feedback on cluster scaling relations. We find L-T and M-T relations in clusters with direct evidence of feedback which are steeper than self-similar, but not atypical compared to previous studies of the full cluster population. While the gas mass rises, the stellar mass remains nearly constant with rising total mass, consistent with earlier studies. This trend is found regardless of central cooling time, implying tight regulation of star formation in central galaxies as their haloes grew, and long-term balance between AGN heating and atmospheric cooling. Our scaling relations are presented in forms that can be incorporated easily into galaxy evolution models.

  18. Totally Active Scintillator Tracker-Calorimeter for the Muon Ionization Cooling Experiment

    CERN Document Server

    AUTHOR|(CDS)2078013; Blondel, Alain

    2014-09-31

    The recent discoveries in particle physics, the Higgs Boson and neutrino oscillations, voiced the need for new machines that can provide higher intensities, energy and precision. To study the neutrino oscillations in great details and to access new physics, a Neutrino Factory stands as an ultimate tool that offers a high intensity, well understood neutrino beam. On the other hand, a Muon Collider is indispensable for better understanding of a Higgs physics. Both machines share similar ingredients and one of them, that is essential to achieve high luminosity of the beams, is beam cooling. And the only feasible method to achieve cooling of a muons beam is based on ionization. An R&D project was established to verify a possibility of such a cooling, Muon Ionization Cooling Experiment (MICE). Its purpose is to build a cooling cell capable of cooling a muon beam by 10% and measure the effect (the cooling effect is attributed to a reduction of beam emittance) with an absolute precision of 0.1%. This is achieve...

  19. Highly porous activated carbon based adsorption cooling system employing difluoromethane and a mixture of pentafluoroethane and difluoromethane

    Science.gov (United States)

    Askalany, Ahmed A.; Saha, Bidyut B.

    2017-01-01

    This paper presents a simulation for a low-grade thermally powered two-beds adsorption cooling system employing HFC-32 and a mixture of HFC-32 and HFC-125 (HFC-410a) with activated carbon of type Maxsorb III. The present simulation model adopts experimentally measured adsorption isotherms, adsorption kinetics and isosteric heat of adsorption data. Effect of operating conditions (mass flow rate of hot water, driving heat source temperature and evaporator temperature) on the system performance has been studied in detail. The simulation results showed that the system could be powered by low-grade heat source temperature (below 85 °C). AC/HFC-32 and AC/HFC-410a adsorption cooling cycles achieved close specific cooling power and coefficient of performance values of 0.15 kW/kg and 0.3, respectively at a regeneration temperature of 90 °C along with evaporator temperature of 10 °C. The investigated semi continuous adsorption cooling system could produce a cooling power of 9 kW.

  20. Damage of actively cooled plasma facing components of magnetic confinement controlled fusion machines

    Energy Technology Data Exchange (ETDEWEB)

    Chevet, G. [Association Euratom-CEA, DSM/DRFC, CEA Cadarache, Saint-Paul-Lez-Durance (France)], E-mail: gaelle.chevet@cea.fr; Schlosser, J. [Association Euratom-CEA, DSM/DRFC, CEA Cadarache, Saint-Paul-Lez-Durance (France); Martin, E.; Herb, V.; Camus, G. [Universite Bordeaux 1, UMR 5801 (CNRS-SAFRAN-CEA-UB1), Laboratoire des Composites Thermostructuraux, F-33600 Pessac (France)

    2009-03-31

    Plasma facing components (PFCs) of magnetic fusion machines have high manufactured residual stresses and have to withstand important stress ranges during operation. These actively cooled PFCs have a carbon fibre composite (CFC) armour and a copper alloy heat sink. Cracks mainly appear in the CFC near the composite/copper interface. In order to analyse damage mechanisms, it is important to well simulate the damage mechanisms both of the CFC and the CFC/Cu interface. This study focuses on the mechanical behaviour of the N11 material for which the scalar ONERA damage model was used. The damage parameters of this model were identified by similarity to a neighbour material, which was extensively analysed, according to the few characterization test results available for the N11. The finite elements calculations predict a high level of damage of the CFC at the interface zone explaining the encountered difficulties in the PFCs fabrication. These results suggest that the damage state of the CFC cells is correlated with a conductivity decrease to explain the temperature increase of the armour surface under fatigue heat load.

  1. CFC/Cu bond damage in actively cooled plasma facing components

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, J [Association Euratom-CEA, CEA/DSM/DRFC, CEA Cadarache, F-13108 Saint Paul Lez Durance (France); Martin, E [LCTS, CNRS UMR 5801, Universite Bordeaux 1, Pessac (France); Henninger, C [LMM, CNRS UMR 7607, Universite P. et M. Curie, Paris (France); Boscary, J [IPP-Euratom Association, Garching (Germany); Camus, G [LCTS, CNRS UMR 5801, Universite Bordeaux 1, Pessac (France); Escourbiac, F [Association Euratom-CEA, CEA/DSM/DRFC, CEA Cadarache, F-13108 Saint Paul Lez Durance (France); Leguillon, D [LMM, CNRS UMR 7607, Universite P. et M. Curie, Paris (France); Missirlian, M [Association Euratom-CEA, CEA/DSM/DRFC, CEA Cadarache, F-13108 Saint Paul Lez Durance (France); Mitteau, R [Association Euratom-CEA, CEA/DSM/DRFC, CEA Cadarache, F-13108 Saint Paul Lez Durance (France)

    2007-03-15

    Carbon fibre composite (CFC) armours have been successfully used for actively cooled plasma facing components (PFCs) of the Tore Supra (TS) tokamak. They were also selected for the divertor of the stellarator W7-X under construction and for the vertical target of the ITER divertor. In TS and W7-X a flat tile design for heat fluxes of 10 MW m{sup -2} has been chosen. To predict the lifetime of such PFCs, it is necessary to analyse the damage mechanisms and to model the damage propagation when the component is exposed to thermal cycling loads. Work has been performed to identify a constitutive law for the CFC and parameters to model crack propagation from the edge singularity. The aim is to predict damage rates and to propose geometric or material improvements to increase the strength and the lifetime of the interfacial bond. For ITER a tube-in-tile concept (monoblock), designed to sustain heat fluxes up to 20 MW m{sup -2}, has been developed. The optimization of the CFC/Cu bond, proposed for flat tiles, could be adopted for the monoblock concept.

  2. Procedure of Active Residual Heat Removal after Emergency Shutdown of High-Temperature-Gas-Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2014-01-01

    Full Text Available After emergency shutdown of high-temperature-gas-cooled reactor, the residual heat of the reactor core should be removed. As the natural circulation process spends too long period of time to be utilized, an active residual heat removal procedure is needed, which makes use of steam generator and start-up loop. During this procedure, the structure of steam generator may suffer cold/heat shock because of the sudden load of coolant or hot helium at the first few minutes. Transient analysis was carried out based on a one-dimensional mathematical model for steam generator and steam pipe of start-up loop to achieve safety and reliability. The results show that steam generator should be discharged and precooled; otherwise, boiling will arise and introduce a cold shock to the boiling tubes and tube sheet when coolant began to circulate prior to the helium. Additionally, in avoiding heat shock caused by the sudden load of helium, the helium circulation should be restricted to start with an extreme low flow rate; meanwhile, the coolant of steam generator (water should have flow rate as large as possible. Finally, a four-step procedure with precooling process of steam generator was recommended; sensitive study for the main parameters was conducted.

  3. The heat removal capability of actively cooled plasma-facing components for the ITER divertor

    Science.gov (United States)

    Missirlian, M.; Richou, M.; Riccardi, B.; Gavila, P.; Loarer, T.; Constans, S.

    2011-12-01

    Non-destructive examination followed by high-heat-flux testing was performed for different small- and medium-scale mock-ups; this included the most recent developments related to actively cooled tungsten (W) or carbon fibre composite (CFC) armoured plasma-facing components. In particular, the heat-removal capability of these mock-ups manufactured by European companies with all the main features of the ITER divertor design was investigated both after manufacturing and after thermal cycling up to 20 MW m-2. Compliance with ITER requirements was explored in terms of bonding quality, heat flux performances and operational compatibility. The main results show an overall good heat-removal capability after the manufacturing process independent of the armour-to-heat sink bonding technology and promising behaviour with respect to thermal fatigue lifetime under heat flux up to 20 MW m-2 for the CFC-armoured tiles and 15 MW m-2 for the W-armoured tiles, respectively.

  4. Damage of actively cooled plasma facing components of magnetic confinement controlled fusion machines

    Science.gov (United States)

    Chevet, G.; Schlosser, J.; Martin, E.; Herb, V.; Camus, G.

    2009-03-01

    Plasma facing components (PFCs) of magnetic fusion machines have high manufactured residual stresses and have to withstand important stress ranges during operation. These actively cooled PFCs have a carbon fibre composite (CFC) armour and a copper alloy heat sink. Cracks mainly appear in the CFC near the composite/copper interface. In order to analyse damage mechanisms, it is important to well simulate the damage mechanisms both of the CFC and the CFC/Cu interface. This study focuses on the mechanical behaviour of the N11 material for which the scalar ONERA damage model was used. The damage parameters of this model were identified by similarity to a neighbour material, which was extensively analysed, according to the few characterization test results available for the N11. The finite elements calculations predict a high level of damage of the CFC at the interface zone explaining the encountered difficulties in the PFCs fabrication. These results suggest that the damage state of the CFC cells is correlated with a conductivity decrease to explain the temperature increase of the armour surface under fatigue heat load.

  5. Ozone Activated Cool Diffusion Flames of Butane Isomers in a Counterflow Facility

    KAUST Repository

    Al Omier, Abdullah Abdulaziz

    2017-04-01

    Proceeding from the aim to reduce global pollution emissions from the continuous burning of hydrocarbons stimulated by increasing energy demand, more efficient and ultra-low emissions’ combustion concepts such as the homogenous charge compression ignition engines (HCCI) have been developed. These new engines rely on the low temperature chemistry (LTC) combustion concept. A detailed investigation of the properties of cool flames, governed by LTC, is essential for the design of these new engines. The primary goal of this work was to build a fundamental counterflow experiment for cool flames studies in a diffusive system, to better understand combustion in LTC engines. The project was intended to provide a basic understanding of the low-temperature reactivity and cool flames properties of butane isomers under atmospheric pressure conditions. This was achieved by establishing self-sustaining cool flames through a novel technique of ozone addition to an oxygen stream in a non-premixed counterflow model. The ignition and extinction limits of butane isomers’ cool flames have been investigated under a variety of strain rates. Results revealed that establishment of cool flames are favored at lower strain rates. Iso-butane was less reactive than n-butane by showing higher ignition and extinction limits. Ozone addition showed a significant influence on cool flame ignition and sustenance; it was found that increasing ozone concentration in the oxidizer stream dramatically increased the reactivity of both fuels. Results showed increased fuel reactivity as the temperature of the fuel stream outlet increased. 4 A numerical analysis was performed to simulate ignition and extinction of the cool flame in diffusive systems. The results revealed that ignition and extinction limits of cool flames are predominantly governed by LTC. The model qualitatively captured experimental trends for both fuels; however, it overpredicted both ignition and extinction limits under all strain rates

  6. Scientific feedback from high heat flux actively cooled PFCs development, realization and first results in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Grosman, A.; Bayetti, P.; Brosset, C.; Bucalossi, J.; Cordier, J.J.; Durocher, A.; Escourbiac, F.; Ghendrih, Ph.; Guilhem, D.; Gunn, J.; Loarer, T.; Lipa, M.; Mitteau, R.; Pegourie, B.; Reichle, R.; Schlosser, J.; Tsitrone, E.; Vallet, J.C

    2004-07-01

    The implementation of actively cooled high heat flux plasma facing components (PFCs) are one of the major ingredients required for operating the Tore Supra tokamak with very long pulses. A pioneering activity has been developed in this field from the very beginning of the device operation that is today culminating with the routine operation of an actively cooled toroidal pumped limiter (TPL) capable to sustain up to 10 MW.m{sup -2} of nominal convected heat flux. A technical feedback is given from the whole development up to the industrialization and focuses on a number of critical issues, such as bonding technology analysis, manufacture processes, repair processes, destructive and non destructive testing. The actual experience in Tore Supra allows to address the question of D retention on carbon walls. Redeposition on surfaces without plasma flux is suspected to cause the final 'burial' of about the injected gas during long discharges. (authors)

  7. Cool temperatures reduce antifungal activity of symbiotic bacteria of threatened amphibians--implications for disease management and patterns of decline.

    Directory of Open Access Journals (Sweden)

    Joshua H Daskin

    Full Text Available Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd, is a widespread disease of amphibians responsible for population declines and extinctions. Some bacteria from amphibians' skins produce antimicrobial substances active against Bd. Supplementing populations of these cutaneous antifungal bacteria might help manage chytridiomycosis in wild amphibians. However, the activity of protective bacteria may depend upon environmental conditions. Biocontrol of Bd in nature thus requires knowledge of how environmental conditions affect their anti-Bd activity. For example, Bd-driven amphibian declines have often occurred at temperatures below Bd's optimum range. It is possible these declines occurred due to reduced anti-Bd activity of bacterial symbionts at cool temperatures. Better understanding of the effects of temperature on chytridiomycosis development could also improve risk evaluation for amphibian populations yet to encounter Bd. We characterized, at a range of temperatures approximating natural seasonal variation, the anti-Bd activity of bacterial symbionts from the skins of three species of rainforest tree frogs (Litoria nannotis, Litoria rheocola, and Litoria serrata. All three species declined during chytridiomycosis outbreaks in the late 1980s and early 1990s and have subsequently recovered to differing extents. We collected anti-Bd bacterial symbionts from frogs and cultured the bacteria at constant temperatures from 8 °C to 33 °C. Using a spectrophotometric assay, we monitored Bd growth in cell-free supernatants (CFSs from each temperature treatment. CFSs from 11 of 24 bacteria showed reduced anti-Bd activity in vitro when they were produced at cool temperatures similar to those encountered by the host species during population declines. Reduced anti-Bd activity of metabolites produced at low temperatures may, therefore, partially explain the association between Bd-driven declines and cool temperatures. We show that to

  8. Cool temperatures reduce antifungal activity of symbiotic bacteria of threatened amphibians--implications for disease management and patterns of decline.

    Science.gov (United States)

    Daskin, Joshua H; Bell, Sara C; Schwarzkopf, Lin; Alford, Ross A

    2014-01-01

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is a widespread disease of amphibians responsible for population declines and extinctions. Some bacteria from amphibians' skins produce antimicrobial substances active against Bd. Supplementing populations of these cutaneous antifungal bacteria might help manage chytridiomycosis in wild amphibians. However, the activity of protective bacteria may depend upon environmental conditions. Biocontrol of Bd in nature thus requires knowledge of how environmental conditions affect their anti-Bd activity. For example, Bd-driven amphibian declines have often occurred at temperatures below Bd's optimum range. It is possible these declines occurred due to reduced anti-Bd activity of bacterial symbionts at cool temperatures. Better understanding of the effects of temperature on chytridiomycosis development could also improve risk evaluation for amphibian populations yet to encounter Bd. We characterized, at a range of temperatures approximating natural seasonal variation, the anti-Bd activity of bacterial symbionts from the skins of three species of rainforest tree frogs (Litoria nannotis, Litoria rheocola, and Litoria serrata). All three species declined during chytridiomycosis outbreaks in the late 1980s and early 1990s and have subsequently recovered to differing extents. We collected anti-Bd bacterial symbionts from frogs and cultured the bacteria at constant temperatures from 8 °C to 33 °C. Using a spectrophotometric assay, we monitored Bd growth in cell-free supernatants (CFSs) from each temperature treatment. CFSs from 11 of 24 bacteria showed reduced anti-Bd activity in vitro when they were produced at cool temperatures similar to those encountered by the host species during population declines. Reduced anti-Bd activity of metabolites produced at low temperatures may, therefore, partially explain the association between Bd-driven declines and cool temperatures. We show that to avoid

  9. Electron cooling

    Science.gov (United States)

    Meshkov, I.; Sidorin, A.

    2004-10-01

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

  10. Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Blaskiewicz, M.

    2011-01-01

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

  11. Novel heating and cooling concept employing rainwater cisterns and thermo-active building systems for a residential building

    Energy Technology Data Exchange (ETDEWEB)

    Kalz, Doreen E.; Wienold, Jan; Fischer, Martin; Cali, Davide [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany)

    2010-02-15

    This paper introduces and evaluates a novel heating and cooling concept employing thermo-active building systems and environmental energy, harnessed from two 11-m{sup 3} rainwater cisterns for a 285-m{sup 2} residential building in passive house standard in Germany. The building strives for a significantly reduced primary energy use with carefully coordinated measures, such as high quality building envelope, by means of vacuum insulated panels, supply and exhaust air system with heat recovery, reduced solar heat gains (solar shading), and the integration of thermal solar collectors and photovoltaic in the plant system. On this premise, a comprehensive long-term monitoring in high time-resolution was carried out for the building for two years with an accompanying commissioning of the building performance. Measurements comprise the energy use for heating, cooling, and ventilation, as well as the auxiliary equipment, the performance of the environmental heat source and sink (rainwater cistern), thermal comfort, and local climatic site conditions. The analysis focuses on the performance and the efficiency of rainwater cisterns as natural heat source and sink as well as the heat pump system. The paper discusses the performance of thermo-active building systems, investigates the thermal comfort, determines the efficiency of the heating/cooling system, and evaluates the total end and primary energy use of the building. (author)

  12. Modelling of steady state erosion of CFC actively water-cooled mock-up for the ITER divertor

    Energy Technology Data Exchange (ETDEWEB)

    Ogorodnikova, O.V. [Departement de Recherches sur la Fusion Controlee, Association Euratom-CEA, CEA-Cadarache, F-13108 Saint Paul Lez Durance cedex (France)], E-mail: igra32@rambler.ru

    2008-04-15

    Calculations of the physical and chemical erosion of CFC (carbon fibre composite) monoblocks as outer vertical target of the ITER divertor during normal operation regimes have been done. Off-normal events and ELM's are not considered here. For a set of components under thermal and particles loads at glancing incident angle, variations in the material properties and/or assembly of defects could result in different erosion of actively-cooled components and, thus, in temperature instabilities. Operation regimes where the temperature instability takes place are investigated. It is shown that the temperature and erosion instabilities, probably, are not a critical point for the present design of ITER vertical target if a realistic variation of material properties is assumed, namely, the difference in the thermal conductivities of the neighbouring monoblocks is 20% and the maximum allowable size of a defect between CFC armour and cooling tube is +/-90{sup o} in circumferential direction from the apex.

  13. Modelling of steady state erosion of CFC actively water-cooled mock-up for the ITER divertor

    Science.gov (United States)

    Ogorodnikova, O. V.

    2008-04-01

    Calculations of the physical and chemical erosion of CFC (carbon fibre composite) monoblocks as outer vertical target of the ITER divertor during normal operation regimes have been done. Off-normal events and ELM's are not considered here. For a set of components under thermal and particles loads at glancing incident angle, variations in the material properties and/or assembly of defects could result in different erosion of actively-cooled components and, thus, in temperature instabilities. Operation regimes where the temperature instability takes place are investigated. It is shown that the temperature and erosion instabilities, probably, are not a critical point for the present design of ITER vertical target if a realistic variation of material properties is assumed, namely, the difference in the thermal conductivities of the neighbouring monoblocks is 20% and the maximum allowable size of a defect between CFC armour and cooling tube is +/-90° in circumferential direction from the apex.

  14. Circulating and plateout activity program for gas-cooled reactors with arbitrary radioactive chains

    Energy Technology Data Exchange (ETDEWEB)

    Apperson, C.E. Jr.

    1978-03-01

    A time-dependent method for estimating the fuel body, circulating, plateout, and filter inventory of a high temperature gas-cooled reactor (HTGR) during normal operation is discussed. The primary coolant model accounts for the source, buildup, decay, and cleanup of isotopes that are gas borne inside the prestressed concrete reactor vessel (PCRV). This method has been implemented in the SUVIUS computer program that is described in detail.

  15. Numerical Investigation of Active Tip-clearance Control through Tip Cooling Injection in an Axial Turbine Cascade

    Institute of Scientific and Technical Information of China (English)

    Maosheng Niu; Shusheng Zang

    2009-01-01

    This paper presents a numerical investigation of an active tip-clearance control method based on cooling injection from the blade tip surface. It aims to study the influences of air injection on controlling tip clearance flow, with emphasis on the effects of the injection location on secondary flow and the potential thermal benefits from the cooling jet. The results show that injection location plays an important role in the redistribution of secondary flow within the cascade passage. Injection located much closer to the pressure-side comer performs better in reducing tip clearance massflow and its associated losses. However, it also intensifies tip passage vortex, due to less re-straint deriving from the reduced tip clearance vortex. Lower plenum total pressure is required to inject equivalent amount of cooling air, but the heat transfer condition on the blade tip surface is a bit worse than that with injection from the reattachment region. Thus the optimum location of air injection should be at the tip separation vortex re-gion.

  16. Warm and Cool Dinosaurs.

    Science.gov (United States)

    Mannlein, Sally

    2001-01-01

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

  17. Variability in cold front activities modulating cool-season evaporation from a southern inland water in the USA

    Science.gov (United States)

    Liu, Heping; Blanken, Peter D.; Weidinger, Tamas; Nordbo, Annika; Vesala, Timo

    2011-04-01

    Understanding seasonal variations in the evaporation of inland waters (e.g., lakes and reservoirs) is important for water resource management as well as the prediction of the hydrological cycles in response to climate change. We analyzed eddy covariance-based evaporation measurements from the Ross Barnett Reservoir (32°26'N, 90°02'W which is always ice-free) in central Mississippi during the cool months (i.e., September-March) of 2007 and 2008, and found that the variability in cold front activities (i.e., passages of cold fronts and cold/dry air masses behind cold fronts) played an important role in modulating the exchange of sensible (H) and latent (λE) heat fluxes. Our analysis showed that 2007's warmer cool season had smaller mean H and λE than 2008's cooler cool season. This implies that the warmer cool season did not accelerate evaporation and heat exchange between the water surface and the atmosphere. Instead, more frequent cold fronts and longer periods of cold/dry air masses behind the cold fronts in 2008 resulted in overall larger H and λE as compared with 2007, this primarily taking the form of sporadic short-term rapid 'pulses' of H and λE losses from the water's surface. These results suggest that future climate-induced changes in frequency of cold fronts and the meteorological properties of the air masses behind cold fronts (e.g., wind speeds, temperature, and humidity), rather than other factors of climate change, would produce significant variations in the water surface's energy fluxes and subsequent evaporation rates.

  18. Application of CATE 2.0 code on evaluating activated corrosion products in a PWR cooling loop

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jingyu; Li, Lu; Chen, Yixue [North China Electric Power Univ., Beijing (China). School of Nuclear Science and Engineering

    2017-03-15

    In PWR plants, most Occupational Radiation Exposure (ORE) for personnel results from Activated Corrosion Products (ACPs) in the cooling loop. In order to evaluate the ACPs in the cooling loop, a three-region transport model is built up based on the theory of driving force from the concentration difference in CATE 2.0 code. In order to analyze the nuclide composition of ACPs, the EAF-2007 nuclear database is embedded in CATE 2.0. The case of MIT PCCL test loop is simulated to test the availability of CATE 2.0 on PWR ACPs evaluation, and the activity of Co-58 and Co-60 after operation for 42 days calculated by CATE 2.0 is consistent with that from the code CRUDSIM adopted by MIT. Then, the nuclide composition of ACPs is analyzed in detail respectively for operation of 42 days and 12 months using CATE 2.0. The results show that the short-lived nuclides contribute a majority of the activity in the regions of in-flux wall and coolant, while the long-lived nuclides contribute most of the activity in the region of out-flux wall.

  19. Effects of acoustic ceiling units on the cooling performance of thermally activated building systems (TABS)

    DEFF Research Database (Denmark)

    Lacarte, Luis Marcos Domínguez; Rage, Niels; Kazanci, Ongun Berk

    2017-01-01

    the effects of two types of free hanging ceiling absorbers (horizontal and vertical) on the cooling performance of the TABS and the implications this has on the occupant thermal comfort. The measurements were carried out in a full-scale TABS test facility. The results show a reduction of 11% of the heat...... absorbers for equivalent levels of sound absorption. A reduction of 12% of the heat removed by the TABS has been measured for vertical sound absorbers (equivalent sound absorption levels to 60% coverage ratio with horizontal sound absorbers). This reduction was of 13% for vertical sound absorbers...

  20. High energy electron cooling

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-09-01

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

  1. Is magma cooling responsible for the periodic activity of Soufrière Hills volcano, Montserrat, West Indies?

    Science.gov (United States)

    Caricchi, Luca; Simpson, Guy; Chelle-Michou, Cyril; Neuberg, Jürgen

    2016-04-01

    After 400 years of quiescence, Soufrière Hills volcano on Montserrat (SHV) started erupting in 1995. Ongoing deformation and sulphur dioxide emission demonstrate that this volcanic systems is still restless, however, after 5 years of inactivity it remains unclear whether magma extrusion will restart. Also, if such periodically observed activity at SHV will restart, can we use past monitoring data to attempt to forecast the reawakening of this volcano? Cooling of volatile saturated magma leads to crystallisation, the formation of gas bubbles and expansion. Such volumetric variations are not only potentially responsible for deformation signals observed at the surface (Caricchi et al., 2014), but also lead to pressurisation of the magmatic reservoir and eventually renewed magma extrusion (Tait et al., 1989). We postulate that volcanic activity observed at SHM over the last 20 years could be essentially the result of the unavoidable progressive cooling of a magmatic body, which was probably assembled over thousands of years and experienced internal segregation of eruptible lenses of magma (Christopher et al., 2015). To test this hypothesis, we performed thermal modelling to test if the cooling of a shallow magma body emplaced since 1990 could account for the monitoring signals observed at SHV. The results show that progressive cooling of a 4km3 volume of melt could explain the deformation rate currently observed. Using the deformation rate obtained from the modelling for the first 15 years of cooling, a reservoir volume of about 13 km3 (Paulatto et al., 2012) and a critical value of overpressure of 10 MPa, it would have taken approximately only 3 years to pressurise the reservoir to the critical pressure and restart magma extrusion. This is in agreement with the time interval between previous pauses at SHV before 2010. Considering the current deformation rates, we speculate that magma extrusion could restart in 6-8 years after the end of the last event in 2010, hence

  2. HHF test with 80x80x1 Be/Cu/SS Mock-ups for verifying the joining technology of the ITER blanket First Wall

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Bae, Young Dug; Kim, Suk Kwon; Hong, Bong Guen; Jeong, Yong Hwan; Park, Jeong Yong; Choi, Byung Kwon; Jung, Hyun Kyu

    2008-11-15

    Through the fabrication of the Cu/SS and Be/Cu joint specimens, fabrication procedure such as material preparation, canning, degassing, HIP (Hot Isostatic Pressing), PHHT (Post HIP heat treatment) was established. The HIP conditions (1050 .deg. C, 100 MPa 2 hr for Cu/SS, 580 .deg. C 100 MPa 2 hr for Be/Cu) were developed through the investigation on joint specimen fabricated with the various HIP conditions; the destructive tests of joint include the microstructure observation of the interface with the examination of the elemental distribution, tension test, bend test, Charpy impact test and fracture toughness test. However, since the joint should be tested under the High Heat Flux (HHF) conditions like the ITER operation for verifying its joint integrity, several HHF tests were performed like the previous HHF test with the Cu/SS, Be/Cu, Be/Cu/SS Mock-ups. In the present study, the HHF test with Be/Cu/SS Mock-ups, which have 80 mm x 80 mm single Be tile and each material depths were kept to be the same as the ITER blanket FW. The Mock-ups fabricated with three kinds of interlayers such as Cr/Ti/Cu, Ti/Cr/Cu, Ti/Cu, which were different from the developed interlayer (Cr/Cu), total 6 Mock-ups were fabricated. Preliminary analysis were performed to decide the test conditions; they were tested with up to 2.5 MW/m2 of heat fluxes and 20 cycles for each Mock-up in a given heat flux. They were tested with JUDITH-1 at FZJ in Germany. During tests, all Mock-ups showed delamination or full detachment of Be tile and it can be concluded that the joints with these interlayers have a bad joining but it can be used as a good data for developing the Be/Cu joint with HIP.

  3. Modular jet impingement assemblies with passive and active flow control for electronics cooling

    Science.gov (United States)

    Zhou, Feng; Dede, Ercan Mehmet; Joshi, Shailesh

    2016-09-13

    Power electronics modules having modular jet impingement assembly utilized to cool heat generating devices are disclosed. The modular jet impingement assemblies include a modular manifold having a distribution recess, one or more angled inlet connection tubes positioned at an inlet end of the modular manifold that fluidly couple the inlet tube to the distribution recess and one or more outlet connection tubes positioned at an outlet end of the modular manifold that fluidly coupling the outlet tube to the distribution recess. The modular jet impingement assemblies include a manifold insert removably positioned within the distribution recess and include one or more inlet branch channels each including an impinging slot and one or more outlet branch channels each including a collecting slot. Further a heat transfer plate coupled to the modular manifold, the heat transfer plate comprising an impingement surface including an array of fins that extend toward the manifold insert.

  4. AHA! A Cool Salt Water/Density Activity--The Joy of Designing a Simple Experiment.

    Science.gov (United States)

    Carlson, Gaylen R.

    1998-01-01

    Describes two science activities concerning water density and shares an idea for combining these activities into a third, completely new activity. Demonstrates the joy of rekindling the spirit of scientific thinking in a typical classroom. (PVD)

  5. A shirt containing multistage phase change material and active cooling components was associated with increased exercise capacity in a hot, humid environment.

    Science.gov (United States)

    McFarlin, Brian K; Henning, Andrea L; Venable, Adam S; Williams, Randall R; Best Sampson, Jill N

    2016-08-01

    Recent advances in clothing design include the incorporation of phase change materials (PCM) and other active cooling components (ACC) to provide better body heat dissipation. The purpose of this study was to determine the effect of wearing a shirt containing multistage PCM/ACC on exercise capacity at low (5.0), moderate-high (7.5) and extreme (9.0) levels of the physiological strain index (PSI). Fourteen individuals tested two shirts (control vs. cooling) during 45-min of interval running in a hot, humid (35 ± 1 °C; 55 ± 6% RH) environment. The cooling shirt resulted in an 8% improvement in exercise capacity at a PSI of 7.5 (p active cooling components.

  6. Danish Cool

    DEFF Research Database (Denmark)

    Toft, Anne Elisabeth

    2016-01-01

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

  7. Dynamic Heat Storage and Cooling Capacity of a Concrete Deck with PCM and Thermally Activated Building System

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2012-01-01

    the performance of the new deck with PCM concrete is the thermal properties of such a new material, as the PCM concrete is yet to be well defined. The results presented in the paper include models in which the PCM concrete material properties, such as thermal conductivity, and specific heat capacity were first......This paper presents a heat storage and cooling concept that utilizes a phase change material (PCM) and a thermally activated building system (TABS) implemented in a hollow core concrete deck. Numerical calculations of the dynamic heat storage capacity of the hollow core concrete deck element...... with and without microencapsulated PCM are presented. The new concrete deck with microencapsulated PCM is the standard deck on which an additional layer of the PCM concrete was added and, at the same time, the latent heat storage was introduced to the construction. The challenge of numerically simulating...

  8. The design of multi-megawatt actively cooled beam dumps for the Neutral-Beam Engineering Test Facility

    Science.gov (United States)

    Paterson, J. A.; Koehler, G.; Wells, R. P.

    1981-10-01

    To test neutral beam sources up to 170 keV, 65 Amps, with 30 second beam on times, actively cooled beam dumps for both the neutral and ionized particles are required. The dumps should be able to dissipate a wide range of power density profiles by utilizing a standard modular panel design which is incorporated into a moveable support structure. The thermal hydraulic design of the panels permit the dissipation of 2 kW/sq cm anywhere on the panel surface. The water requirements of the dumps are optimized by restricting the flow to panel sections where the heat flux falls short of the design value. The mechanical design of the beam-dump structures is described along with tests performed on two different panel designs. The dissipation capabilities of the panels were tested at the critical regions to verify their use in the beam dump assemblies.

  9. Self-sufficient and active PCM cooling convectors. Reduction of installed capacity; Autarkie en actieve PCM-koelconvectoren. Geinstalleerd vermogen kan fors omlaag

    Energy Technology Data Exchange (ETDEWEB)

    Van Holten, P. [VSL Air-o-vent, Grimbergen (Belgium); Schmitz, H. [Verwol Klimaatplafonds, Delft (Netherlands)

    2006-06-15

    Conventional active cooling convectors are supplied with a hot water and cold water battery. In the innovative active PCM (phase change materials) cooling convectors the cold water battery is replaced by a battery of PCM plates which operate as a cooler in the summer and as a cooler and/or heater in the other seasons. [Dutch] Conventionele actieve koelconvectoren zijn normaliter voorzien van een warmwater- en een koelwaterbatterij. In de innovatieve actieve PCM-koelconvector is de koelwaterbatterij vervangen door een batterij van PCM-platen die fungeren als koeling voor de zomer en als koeling en verwarming voor de overige jaargetijden.Voor dit Iaatstgenoemde 2-pijpsklimaatsysteem komt steeds meer belangstelling.

  10. The Cosmic History of Hot Gas Cooling and Radio AGN Activity in Massive Early-Type Galaxies

    Science.gov (United States)

    Danielson, A. L. R.; Lehmer, B. D.; Alexander, D. M.; Brandt, W. M.; Luo, B.; Miller, N.; Xue, Y. Q.; Stott, J. P.

    2012-01-01

    We study the X-ray properties of 393 optically selected early-type galaxies (ETGs) over the redshift range of z approx equals 0.0-1.2 in the Chandra Deep Fields. To measure the average X-ray properties of the ETG population, we use X-ray stacking analyses with a subset of 158 passive ETGs (148 of which were individually undetected in X-ray). This ETG subset was constructed to span the redshift ranges of z = 0.1-1.2 in the approx equals 4 Ms CDF-S and approx equals 2 Ms CDF-N and z = 0.1-0.6 in the approx equals 250 ks E-CDF-S where the contribution from individually undetected AGNs is expected to be negligible in our stacking. We find that 55 of the ETGs are detected individually in the X-rays, and 12 of these galaxies have properties consistent with being passive hot-gas dominated systems (i.e., systems not dominated by an X-ray bright Active Galactic Nucleus; AGN). On the basis of our analyses, we find little evolution in the mean 0.5-2 keY to B-band luminosity ratio (L(sub x) /L(sub Beta) varies as [1 +z]) since z approx equals 1.2, implying that some heating mechanism prevents the gas from cooling in these systems. We consider that feedback from radio-mode AGN activity could be responsible for heating the gas. We select radio AGNs in the ETG population using their far-infrared/radio flux ratio. Our radio observations allow us to constrain the duty cycle history of radio AGN activity in our ETG sample. We estimate that if scaling relations between radio and mechanical power hold out to z approx equals 1.2 for the ETG population being studied here, the average mechanical power from AGN activity is a factor of approx equals1.4 -- 2.6 times larger than the average radiative cooling power from hot gas over the redshift range z approx equals 0-1.2. The excess of inferred AGN mechanical power from these ETGs is consistent with that found in the local Universe for similar types of galaxies.

  11. Terrestrial sensitivity to abrupt cooling recorded by aeolian activity in northwest Ohio, USA

    Science.gov (United States)

    Campbell, M.C.; Fisher, T.G.; Goble, R.J.

    2011-01-01

    Optically stimulated luminescence dated sand dunes and Pleistocene beach ridges in northwest Ohio are used to reconstruct landscape modification more than 5000. yr after deglaciation. Four of the OSL ages (13.3-11.1. ka) cluster around the Younger Dryas cold event, five ages (10.8-8.2. ka) cluster around the Preboreal, one young age (0.9-0.7. ka) records more recent aeolian activity, and one age of 15.1-13.1. ka dates a barrier spit in Lake Warren. In northwest Ohio, both landscape instability recorded by aeolian activity and a vegetation response recorded by pollen are coeval with the Younger Dryas. However, the climate conditions during the Preboreal resulting in aeolian activity are not recorded in the available pollen records. From this, we conclude that aeolian dunes and surfaces susceptible to deflation are sensitive to cooler, drier episodes of climate and can complement pollen data. Younger Dryas and Preboreal aged aeolian activity in northwestern Ohio coincides with aeolian records elsewhere in the Great Lakes region east of the prairie-forest ecotone. ?? 2011 University of Washington.

  12. Hydrothermal activity in Tertiary Icelandic crust: Implication for cooling processes along slow-spreading mid-ocean ridges

    Science.gov (United States)

    Pałgan, D.; Devey, C. W.; Yeo, I. A.

    2015-12-01

    Known hydrothermal activity along the Mid-Atlantic Ridge is mostly high-temperature venting, controlled by volcano-tectonic processes confined to ridge axes and neotectonic zones ~15km wide on each side of the axis (e.g. TAG or Snake Pit). However, extensive exploration and discoveries of new hydrothermal fields in off-axis regions (e.g. Lost City, MAR) show that hydrothermalism may, in some areas, be dominated by off-axis venting. Little is known about nature of such systems, including whether low-temperature "diffuse" venting dominates rather than high-temperature black-smokers. This is particularly interesting since such systems may transport up to 90% of the hydrothermal heat to the oceans. In this study we use Icelandic hot springs as onshore analogues for off-shore hydrothermal activity along the MAR to better understand volcano-tectonic controls on their occurrence, along with processes supporting fluid circulation. Iceland is a unique laboratory to study how new oceanic crust cools and suggests that old crust may not be as inactive as previously thought. Our results show that Tertiary (>3.3 Myr) crust of Iceland (Westfjords) has widespread low-temperature hydrothermal activity. Lack of tectonism (indicated by lack of seismicity), along with field research suggest that faults in Westfjords are no longer active and that once sealed, can no longer support hydrothermal circulation, i.e. none of the hot springs in the area occur along faults. Instead, dyke margins provide open and permeable fluid migration pathways. Furthermore, we suggest that the Reykjanes Ridge (south of Iceland) may be similar to Westfjords with hydrothermalism dominated by off-axis venting. Using bathymetric data we infer dyke positions and suggest potential sites for future exploration located away from neotectonic zone. We also emphasise the importance of biological observations in seeking for low-temperature hydrothermal activity, since chemical or optical methods are not sufficient.

  13. Critical temperature ranges of hypothermia-induced platelet activation: possible implications for cooling patients in cardiac surgery.

    Science.gov (United States)

    Straub, Andreas; Breuer, Melanie; Wendel, Hans P; Peter, Karlheinz; Dietz, Klaus; Ziemer, Gerhard

    2007-04-01

    Cooling of the patient is routinely applied in cardiac surgery to protect organs against ischemia. Hypothermia induces activation of platelets, but the effects of temperatures such as used during cardiac surgery are not well described. To investigate this in an in-vitro study heparinized whole blood was incubated at different temperatures (37 degrees C, 34.5 degrees C, 32 degrees C, 29.5 degrees C, 27 degrees C, 24.5 degrees C, 22 degrees C, 19.5 degrees C and 17 degrees C). The effect of these temperatures on aggregation, P-selectin expression, GP IIb/IIIa activation and platelet microparticle (PMP) formation of unstimulated and ADP-stimulated platelets of 36 subjects was evaluated in flow cytometry. A four-parametric logistic model was fitted to depict the temperature effect on platelet parameters. Lower temperatures increased aggregates, P-selectin expression, and GP IIb/IIIa activation. The number of PMPs decreases with hypothermia. Additional experiments revealed a slight influence of heparin on platelet P-selectin expression but excluded an effect of this anticoagulant on the other evaluated parameters. Threshold temperatures, which mark 5% changes of platelet parameters compared to values at 37 degrees C, were calculated. On ADP-stimulated platelets the thresholds for P-selectin expression and GP IIb/IIa activation are 34.0 degrees C and 36.4 degrees C, respectively, and lie in the temperature range routinely applied in cardiac surgery. Hypothermia-induced platelet activation may develop in most patients undergoing cardiac surgery, possibly resulting in thromboembolic events, coagulation defects, and proinflammatory leukocyte bridging by P-selectin bearing platelets and PMPs. These findings suggest that pharmacological protection of platelets against hypothermia-induced damage may be beneficial during cardiac surgery.

  14. Effect of soaking, boiling, and steaming on total phenolic contentand antioxidant activities of cool season food legumes.

    Science.gov (United States)

    Xu, Baojun; Chang, Sam K C

    2008-09-01

    The effects of soaking, boiling and steaming processes on the total phenolic components and antioxidant activity in commonly consumed cool season food legumes (CSFL's), including green pea, yellow pea, chickpea and lentil were investigated. As compared to original unprocessed legumes, all processing steps caused significant (pboiling treatments caused significant (pboiling and pressure steaming caused significant (pboiling treatments. To obtain cooked legumes with similar palatability and firmness, pressure boiling shortened processing time as compared to atmospheric boiling, resulted in insignificant differences in TPC, DPPH for green and yellow pea. However, TPC and DPPH in cooked lentils differed significantly between atmospheric and pressure boiling. As compared to atmospheric processes, pressure processes significantly increased ORAC values in both boiled and steamed CSFL's. Greater TPC, DPPH and ORAC values were detected in boiling water than that in soaking and steaming water. Boiling also caused more solid loss than steaming. Steam processing exhibited several advantages in retaining the integrity of the legume appearance and texture of the cooked product, shortening process time, and greater retention of antioxidant components and activities. Copyright © 2008 Elsevier Ltd. All rights reserved.

  15. Program plan for reliability and maintainability in active solar heating and cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    This document presents a plan for the Department of Energy, Office of Solar Applications for Buildings program addressing reliability and maintainability (R and M) of active solar energy systems. The goal of the R and M program is to accelerate the removal of reliability and maintainability as major concerns impeding the widespread adoption of solar energy systems. Specific objectives that support that goal are as follows: (1) provide all groups that have solar R and M concerns with the information that is available to the program and that can assist in alleviating those concerns; (2) assist the solar energy industry in improving levels of R and M performance in state-of-the-art solar energy systems, components, and materials; (3) assist in the early development of a viable infrastructure for the design, manufacture, installation, and maintenance of reliable, maintainable, and durable solar energy systems; (4) assist in the development of appropriate standards, code provisions, and certification programs relating to the R and M performance of solar energy systems, components, and materials; and (5) develop the information required to support the other activities within the R and M program. These objectives correspond to five areas of action: regulations, research and development, technology transfer, solar industry infrastructure development, and data collection and analysis. (WHK)

  16. High packing density laser diode stack arrays using Al-free active region laser bars with a broad waveguide and discrete copper microchannel-cooled heatsinks

    Institute of Scientific and Technical Information of China (English)

    Zhigang Liu; Gaozhan Fang; Kecheng Feng

    2009-01-01

    A high packing density laser diode stack array is developed utilizing Al-free active region laser bars with a broad waveguide and discrete copper microchannel-cooled heatsinks. The microchannel cooling technology leads to a 10-bar laser diode stack array having the thermal resistance of 0.199 ℃/W, and enables the device to be operated under continuous-wave (CW) condition at an output power of 1200 W. The thickness of the discrete copper heatsink is only 1.5 mm, which results in a high packing density and a small bar pitch of 1.8 mm.

  17. Infrared surface temperature measurements for long pulse operation, and real time feedback control in Tore-Supra, an actively cooled Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Guilhem, D.; Adjeroud, B.; Balorin, C.; Buravand, Y.; Bertrand, B.; Bondil, J.L.; Desgranges, C.; Gauthier, E.; Lipa, M.; Messina, P.; Missirlian, M.; Mitteau, R.; Moulin, D.; Pocheau, C.; Portafaix, C.; Reichle, R.; Roche, H.; Saille, A.; Vallet, S

    2004-07-01

    Tore-Supra has a steady-state magnetic field using super-conducting magnets and water-cooled plasma facing components for high performances long pulse plasma discharges. When not actively cooled, plasma-facing components can only accumulate a limited amount of energy since the temperature increase continuously (T proportional to {radical}(t)) during the discharge until radiation cooling is equal to the incoming heat flux (T > 1800 K). Such an environment is found in most today Tokamaks. In the present paper we report the recent results of Tore-Supra, especially the design of the new generation of infrared endoscopes to measure the surface temperature of the plasma facing components. The Tore-Supra infrared thermography system is composed of 7 infrared endoscopes, this system is described in details in the paper, the new JET infrared thermography system is presented and some insights of the ITER set of visible/infrared endoscope is given. (authors)

  18. Ventilative Cooling

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols; Kolokotroni, Maria

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

  19. Damage prediction of carbon fibre composite armoured actively cooled plasma-facing components under cycling heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Chevet, G; Schlosser, J; Courtois, X; Escourbiac, F; Missirlian, M [CEA, IRFM, F-13108 Saint Paul Lez Durance (France); Herb, V; Martin, E; Camus, G [LCTS, CNRS UMR 5801, Universite Bordeaux 1, Pessac (France); Braccini, M [SIMaP, CNRS UMR 5266, Grenoble (France)], E-mail: gaelle.chevet@cea.fr

    2009-12-15

    In order to predict the lifetime of carbon fibre composite (CFC) armoured plasma-facing components in magnetic fusion devices, it is necessary to analyse the damage mechanisms and to model the damage propagation under cycling heat loads. At Tore Supra studies have been launched to better understand the damage process of the armoured flat tile elements of the actively cooled toroidal pump limiter, leading to the characterization of the damageable mechanical behaviour of the used N11 CFC material and of the CFC/Cu bond. Up until now the calculations have shown damage developing in the CFC (within the zone submitted to high shear stress) and in the bond (from the free edge of the CFC/Cu interface). Damage is due to manufacturing shear stresses and does not evolve under heat due to stress relaxation. For the ITER divertor, NB31 material has been characterized and the characterization of NB41 is in progress. Finite element calculations show again the development of CFC damage in the high shear stress zones after manufacturing. Stresses also decrease under heat flux so the damage does not evolve. The characterization of the CFC/Cu bond is more complex due to the monoblock geometry, which leads to more scattered stresses. These calculations allow the fabrication difficulties to be better understood and will help to analyse future high heat flux tests on various mock-ups.

  20. Cryogenic cooling system for HTS cable

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shigeru [Taiyo Nippon Sanso, Tsukuba (Japan)

    2017-06-15

    Recently, Research and development activity of HTS (High Temperature Superconducting) power application is very progressive worldwide. Especially, HTS cable system and HTSFCL (HTS Fault current limiter) system are proceeding to practical stages. In such system and equipment, cryogenic cooling system, which makes HTS equipment cooled lower than critical temperature, is one of crucial components. In this article, cryogenic cooling system for HTS application, mainly cable, is reviewed. Cryogenic cooling system can be categorized into conduction cooling system and immersion cooling system. In practical HTS power application area, immersion cooling system with sub-cooled liquid nitrogen is preferred. The immersion cooling system is besides grouped into open cycle system and closed cycle system. Turbo-Brayton refrigerator is a key component for closed cycle system. Those two cooling systems are focused in this article. And, each design and component of the cooling system is explained.

  1. A high-resolution lake sediment record of glacier activity from SE Greenland defines abrupt Holocene cooling events

    Science.gov (United States)

    Balascio, N. L.; Bradley, R. S.; D'Andrea, W. J.

    2013-12-01

    Orbital driven changes in high latitude summer insolation during the Holocene are responsible for the primary millennial-scale climate trends in the Arctic. Following deglaciation, maximum summer temperatures generally occurred during the early to mid-Holocene and declined through the late Holocene. Superimposed on this gradual cooling trend are centennial- and decadal-scale intervals that indicate more rapid perturbations of the arctic climate system. Highly resolved sedimentary records from terrestrial and marine sites help to better characterize climate system dynamics during the Holocene and investigate forcing and feedback mechanism that operate on different timescales. Reconstructing glacial activity can provide valuable paleoclimate information about trends in summer temperature and/or winter precipitation. Proglacial lakes contain sediment archives of meltwater input from glaciers and typically have high sedimentation rates preserving detailed information on glacial activity. However, interpreting proglacial sedimentary records can be difficult because 1) there may be significant input of sediment from non-glacial sources, 2) there is often a lack of organic material for radiocarbon dating, and 3) not all glaciers are sensitive to rapid climatic changes. Here we present a c. 10 cal ka BP record of glacier activity from Kulusuk Lake (65.6°N, 37.1°W; 202 m a.s.l.), a proglacial lake in southeast Greenland that is well constrained by radiocarbon dates and shows a clear signal of changes in glacial input throughout the Holocene. Kulusuk Lake is presently fed by meltwater from two cirque glaciers. It has a small catchment and no other significant source of sediment input. A 3.5 m sediment core contains distinct lithologic changes defined by grain size, magnetic susceptibility, organic content, and scanning XRF data. During the early Holocene, an overall decrease in meltwater input from 8.7-7.7 ka indicates the retreat of the glaciers in response to regional

  2. Explosive Ordnance Disposal (EOD) Ensembles: Biophysical Characteristics and Predicted Work Times With and Without Chemical Protection and Active Cooling Systems

    Science.gov (United States)

    2015-04-29

    Disposal (EOD) configuration elements 4 3 Three-piece liquid circulating personal cooling suit and ice -based 100V cooling unit; (BCS4 Med-Eng...wearer from immediate area blast threats. While the ultimate goal of these suits is to protect EOD technicians from fragmentation and blast , the...the military. Technicians wear fully encapsulating EOD suits designed to protect the individual wearer from immediate area blast threats. While the

  3. Cool snacks

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  4. Cooling tower waste reduction

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-05-01

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

  5. Stochastic cooling

    Energy Technology Data Exchange (ETDEWEB)

    Bisognano, J.; Leemann, C.

    1982-03-01

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

  6. A full-scale experimental set-up for assessing the energy performance of radiant wall and active chilled beam for cooling buildings

    DEFF Research Database (Denmark)

    Le Dreau, Jerome; Heiselberg, Per; Jensen, Rasmus Lund

    2015-01-01

    in decreasing the cooling need of the radiant wall compared to the active chilled beam. It has also been observed that the type and repartition of heat load have an influence on the cooling demand. Regarding the comfort level, both terminals met the general requirements, except at high solar heat gains......Full-scale experiments under both steady-state and dynamic conditions have been performed to compare the energy performance of a radiant wall and an active chilled beam. From these experiments, it has been observed that the radiant wall is a more secure and efficient way of removing heat from...... the test room than the active chilled beam. The energy saving, which can be estimated to around 10%, is due to increased ventilation losses. The asymmetry between air and radiant temperature, the air temperature gradient and the possible short-circuit between inlet and outlet play an equally important role...

  7. A very cool cooling system

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-20

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

  9. Cooling technique

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-31

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

  10. Kinetic model for predicting the concentrations of active halogens species in chlorinated saline cooling waters. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Haag, W.R.; Lietzke, M.H.

    1981-08-01

    A kinetic model has been developed for describing the speciation of chlorine-produced oxidants in seawater as a function of time. The model is applicable under a broad variety of conditions, including all pH range, salinities, temperatures, ammonia concentrations, organic amine concentrations, and chlorine doses likely to be encountered during power plant cooling water chlorination. However, the effects of sunlight are not considered. The model can also be applied to freshwater and recirculating water systems with cooling towers. The results of the model agree with expectation, however, complete verification is not feasible at the present because analytical methods for some of the predicted species are lacking.

  11. Electronic cooling using thermoelectric devices

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-18

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

  12. Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; C.J. Wharton; A.J. Caffrey; J.B. McCabe; C. DeW. Van Siclen

    2013-10-01

    Prompt Gamma Neutron Activation (PGNAA) systems require the use of a gamma-ray spectrometer to record the gamma-ray spectrum of an object under test and allow the determination of the object’s composition. Field-portable systems, such as Idaho National Laboratory’s PINS system, have used standard liquid-nitrogen-cooled high-purity germanium (HPGe) detectors to perform this function. These detectors have performed very well in the past, but the requirement of liquid-nitrogen cooling limits their use to areas where liquid nitrogen is readily available or produced on-site. Also, having a relatively large volume of liquid nitrogen close to the detector can impact some assessments, possibly leading to a false detection of explosives or other nitrogen-containing chemical. Use of a mechanically-cooled HPGe detector is therefore very attractive for PGNAA applications where nitrogen detection is critical or where liquid-nitrogen logistics are problematic. Mechanically-cooled HPGe detectors constructed from p-type germanium, such as Ortec’s trans-SPEC, have been commercially available for several years. In order to assess whether these detectors would be suitable for use in a fielded PGNAA system, Idaho National Laboratory (INL) has been performing a number of tests of the resistance of mechanically-cooled HPGe detectors to neutron damage. These detectors have been standard commercially-available p-type HPGe detectors as well as prototype n-type HPGe detectors. These tests compare the performance of these different detector types as a function of crystal temperature and incident neutron fluence on the crystal.

  13. ATLAS - Liquid Cooling Systems

    CERN Multimedia

    Bonneau, P.

    1998-01-01

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

  14. Plutonium and Minor Actinide Management in Thermal High-Temperature Gas-Cooled Reactors. Publishable Final Activity Report

    Energy Technology Data Exchange (ETDEWEB)

    Kuijper, J.C., E-mail: kuijper@nrg.eu [Nuclear Research and Consultancy Group (NRG), Petten (Netherlands); Somers, J.; Van Den Durpel, L.; Chauvet, V.; Cerullo, N.; Cetnar, J.; Abram, T.; Bakker, K.; Bomboni, E.; Bernnat, W.; Domanska, J.G.; Girardi, E.; De Haas, J.B.M.; Hesketh, K.; Hiernaut, J.P.; Hossain, K.; Jonnet, J.; Kim, Y.; Kloosterman, J.L.; Kopec, M.; Murgatroyd, J.; Millington, D.; Lecarpentier, D.; Lomonaco, G.; McEachern, D.; Meier, A.; Mignanelli, M.; Nabielek, H.; Oppe, J.; Petrov, B.Y.; Pohl, C.; Ruetten, H.J.; Schihab, S.; Toury, G.; Trakas, C.; Venneri, F.; Verfondern, K.; Werner, H.; Wiss, T.; Zakova, J.

    2010-11-15

    The PUMA project -the acronym stands for 'Plutonium and Minor Actinide Management in Thermal High-Temperature Gas-Cooled Reactors'- was a Specific Targeted Research Project (STREP) within the EURATOM 6th Framework Program (EU FP6). The PUMA project ran from September 1, 2006, until August 31, 2009, and was executed by a consortium of 14 European partner organisations and one from the USA. This report serves 2 purposes. It is both the 'Publishable Final Activity Report' and the 'Final (Summary) Report', describing, per Work Package, the specific objectives, research activities, main conclusions, recommendations and supporting documents. PUMA's main objective was to investigate the possibilities for the utilisation and transmutation of plutonium and especially minor actinides in contemporary and future (high temperature) gas-cooled reactor designs, which are promising tools for improving the sustainability of the nuclear fuel cycle. This contributes to the reduction of Pu and MA stockpiles, and also to the development of safe and sustainable reactors for CO{sub 2}-free energy generation. The PUMA project has assessed the impact of the introduction of Pu/MA-burning HTRs at three levels: fuel and fuel performance (modelling), reactor (transmutation performance and safety) and reactor/fuel cycle facility park. Earlier projects already indicated favourable characteristics of HTRs with respect to Pu burning. So, core physics of Pu/MA fuel cycles for HTRs has been investigated to study the CP fuel and reactor characteristics and to assure nuclear stability of a Pu/MA HTR core, under both normal and abnormal operating conditions. The starting point of this investigation comprised the two main contemporary HTR designs, viz. the pebble-bed type HTR, represented by the South-African PBMR, and hexagonal block type HTR, represented by the GT-MHR. The results (once again) demonstrate the flexibility of the contemporary (and near future) HTR

  15. Plutonium and Minor Actinide Management in Thermal High-Temperature Gas-Cooled Reactors. Publishable Final Activity Report

    Energy Technology Data Exchange (ETDEWEB)

    Kuijper, J.C., E-mail: kuijper@nrg.eu [Nuclear Research and Consultancy Group (NRG), Petten (Netherlands); Somers, J.; Van Den Durpel, L.; Chauvet, V.; Cerullo, N.; Cetnar, J.; Abram, T.; Bakker, K.; Bomboni, E.; Bernnat, W.; Domanska, J.G.; Girardi, E.; De Haas, J.B.M.; Hesketh, K.; Hiernaut, J.P.; Hossain, K.; Jonnet, J.; Kim, Y.; Kloosterman, J.L.; Kopec, M.; Murgatroyd, J.; Millington, D.; Lecarpentier, D.; Lomonaco, G.; McEachern, D.; Meier, A.; Mignanelli, M.; Nabielek, H.; Oppe, J.; Petrov, B.Y.; Pohl, C.; Ruetten, H.J.; Schihab, S.; Toury, G.; Trakas, C.; Venneri, F.; Verfondern, K.; Werner, H.; Wiss, T.; Zakova, J.

    2010-11-15

    The PUMA project -the acronym stands for 'Plutonium and Minor Actinide Management in Thermal High-Temperature Gas-Cooled Reactors'- was a Specific Targeted Research Project (STREP) within the EURATOM 6th Framework Program (EU FP6). The PUMA project ran from September 1, 2006, until August 31, 2009, and was executed by a consortium of 14 European partner organisations and one from the USA. This report serves 2 purposes. It is both the 'Publishable Final Activity Report' and the 'Final (Summary) Report', describing, per Work Package, the specific objectives, research activities, main conclusions, recommendations and supporting documents. PUMA's main objective was to investigate the possibilities for the utilisation and transmutation of plutonium and especially minor actinides in contemporary and future (high temperature) gas-cooled reactor designs, which are promising tools for improving the sustainability of the nuclear fuel cycle. This contributes to the reduction of Pu and MA stockpiles, and also to the development of safe and sustainable reactors for CO{sub 2}-free energy generation. The PUMA project has assessed the impact of the introduction of Pu/MA-burning HTRs at three levels: fuel and fuel performance (modelling), reactor (transmutation performance and safety) and reactor/fuel cycle facility park. Earlier projects already indicated favourable characteristics of HTRs with respect to Pu burning. So, core physics of Pu/MA fuel cycles for HTRs has been investigated to study the CP fuel and reactor characteristics and to assure nuclear stability of a Pu/MA HTR core, under both normal and abnormal operating conditions. The starting point of this investigation comprised the two main contemporary HTR designs, viz. the pebble-bed type HTR, represented by the South-African PBMR, and hexagonal block type HTR, represented by the GT-MHR. The results (once again) demonstrate the flexibility of the contemporary (and near future) HTR

  16. Microgravity experiments on boiling and applications: research activity of advanced high heat flux cooling technology for electronic devices in Japan.

    Science.gov (United States)

    Suzuki, Koichi; Kawamura, Hiroshi

    2004-11-01

    Research and development on advanced high heat flux cooling technology for electronic devices has been carried out as the Project of Fundamental Technology Development for Energy Conservation, promoted by the New Energy and Industrial Technology Development Organization of Japan (NEDO). Based on the microgravity experiments on boiling heat transfer, the following useful results have obtained for the cooling of electronic devices. In subcooled flow boiling in a small channel, heat flux increases considerably more than the ordinary critical heat flux with microbubble emission in transition boiling, and dry out of the heating surface is disturbed. Successful enhancement of heat transfer is achieved by a capillary effect from grooved surface dual subchannels on the liquid supply. The critical heat flux increases 30-40 percent more than for ordinary subchannels. A self-wetting mechanism has been proposed, following investigation of bubble behavior in pool boiling of binary mixtures under microgravity. Ideas and a new concept have been proposed for the design of future cooling system in power electronics.

  17. Cool visitors

    CERN Multimedia

    2006-01-01

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

  18. Solar heating and cooling of buildings: activities of the private sector of the building community and its perceived needs relative to increased activity

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    A description of the state of affairs existing in the private sector of the building community between mid-1974 and mid-1975 with regard to solar heating and cooling of buildings is presentd. Also, information on the needs perceived by the private sector with regard to governmental actions (besides research) required to induce widespread application of solar energy for the heating and cooling of buildings is given. The information is based on surveys, data obtained at workshops, sales literature of manufacturers, symposia, and miscellaneous correspondence. Selected interests and projects of individuals and organizations are described. (WHK)

  19. Leak tightness tests on actively cooled plasma facing components: Lessons learned from Tore Supra experience and perspectives for the new fusion machines

    Energy Technology Data Exchange (ETDEWEB)

    Chantant, M., E-mail: michel.chantant@cea.fr; Lambert, R.; Gargiulo, L.; Hatchressian, J.-C.; Guilhem, D.; Samaille, F.; Soler, B.

    2015-10-15

    Highlights: • Test procedures for the qualification of the tightness of actively cooled plasma facing components were defined. • The test is performed after the component manufacturing and before its set-up in the vacuum vessel. • It allows improving the fusion machine availability. • The lessons of tests over 20 years at Tore Supra are presented. - Abstract: The fusion machines under development or construction (ITER, W7X) use several hundreds of actively cooled plasma facing components (ACPFC). They are submitted to leak tightness requirements in order to get an appropriate vacuum level in the vessel to create the plasma. During the ACPFC manufacturing and before their installation in the machine, their leak tightness performance must be measured to check that they fulfill the vacuum requirements. A relevant procedure is needed which allows to segregate potential defects. It must also be optimized in terms of test duration and costs. Tore Supra, as an actively cooled Tokamak, experienced several leaks on ACPFCs during the commissioning and during the operation of the machine. A test procedure was then defined and several test facilities were set-up. Since 1990 the tightness of all the new ACPFCs is systematically tested before their installation in Tore Supra. During the qualification test, the component is set up in a vacuum test tank, and its cooling circuits are pressurized with helium. It is submitted to 3 temperature cycles from room temperature up to the baking temperature level in Tore Supra (200 °C) and two pressurization tests are performed (6 MPa at room temperature and 4 MPa at 200 °C) at each stage. At the end of the last cycle when the ACPFC is at room temperature and pressurized with helium at 6 MPa, the measured leak rate must be lower than 5 × 10{sup −11} Pa m{sup 3} s{sup −1}, the pressure in the test tank being <5 × 10{sup −5} Pa. A large experience has been gained on ACPFCs with carbon parts on stainless steel and Cu

  20. Improvement of non destructive infrared test bed SATIR for examination of actively cooled tungsten armour Plasma Facing Components

    Energy Technology Data Exchange (ETDEWEB)

    Vignal, N., E-mail: nicolas.vignal@cea.fr; Desgranges, C.; Cantone, V.; Richou, M.; Courtois, X.; Missirlian, M.; Magaud, Ph.

    2013-10-15

    Highlights: • Non destructive infrared techniques for control ITER like PFCs. • Reflective surface such as W induce a measurement temperature error. • Numerical data processing by evaluation of the local emissivity. • SATIR test bed can control metallic surface with low and variable emissivity. -- Abstract: For steady state (magnetic) thermonuclear fusion devices which need large power exhaust capability and have to withstand heat fluxes in the range 10–20 MW m{sup −2}, advanced Plasma Facing Components (PFCs) have been developed. The importance of PFCs for operating tokamaks requests to verify their manufacturing quality before mounting. SATIR is an IR test bed validated and recognized as a reliable and suitable tool to detect cooling defaults on PFCs with CFC armour material. Current tokamak developments implement metallic armour materials for first wall and divertor; their low emissivity causes several difficulties for infrared thermography control. We present SATIR infrared thermography test bed improvements for W monoblocks components without defect and with calibrated defects. These results are compared to ultrasonic inspection. This study demonstrates that SATIR method is fully usable for PFCs with low emissivity armour material.

  1. Hybrid radiator cooling system

    Science.gov (United States)

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

    2016-03-15

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

  2. Turbulence and cooling in cluster cores

    CERN Document Server

    Banerjee, Nilanjan

    2014-01-01

    We study the interplay between turbulent heating, mixing, and radiative cooling in an idealized model of cool cluster cores. Active galactic nuclei (AGN) jets are expected to drive turbulence and heat cluster cores. Cooling of the intracluster medium (ICM) and stirring by AGN jets are tightly coupled in a feedback loop. We impose the feedback loop by balancing radiative cooling with turbulent heating. In addition to heating the plasma, turbulence also mixes it, suppressing the formation of cold gas at small scales. In this regard, the effect of turbulence is analogous to thermal conduction. For uniform plasma in thermal balance (turbulent heating balancing radiative cooling), cold gas condenses only if the cooling time is shorter than the mixing time. This condition requires the turbulent kinetic energy to be $\\gtrsim$ the plasma internal energy; such high velocities in cool cores are ruled out by observations. The results with realistic magnetic fields and thermal conduction are qualitatively similar to the ...

  3. Heat Transfer Augmentation for Electronic Cooling

    Directory of Open Access Journals (Sweden)

    Suabsakul Gururatana

    2012-01-01

    Full Text Available Problem statement: The performance of electronic devices has been improving along with the rapid technology development. Cooling of electronic systems is consequently essential in controlling the component temperature and avoiding any hot spot. The study aims to review the present electronic cooling methods which are widely used in electronic devices. Approach: There are several methods to cool down the electronics components such as the pin-fin heat sink, confined jet impingement, heat pipe, micro heat sink and so on. Results: The cooling techniques can obviously increase heat transfer rate. Nonetheless, for active and passive cooling methods the pressure drop could extremely rise, when the heat transfer rate is increased. Conclusion: When the cooling techniques are used, it is clearly seen that the heat transfer increases with pressure drop. To avoid excessive expense due to high pressure drop, optimization method is required to obtain optimum cost and cooling rate.

  4. Floor cooling and air-cooling, the effects on thermal comfort or different cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Sijpheer, N.C.; Bakker, E.J.; Ligthart, F.A.T.M.; Opstelten, I.J. [ECN Energie in de Gebouwde Omgeving en Netten, Petten (Netherlands)

    2007-09-15

    One of the research areas of the Energy research Centre of the Netherlands (ECN) concerns the built environment. Several facilities to conduct research activities are at ECN's disposal. One of these facilities, are five research dwellings located on the premises of ECN. Measured data from these facilities together with weather data and computer models are used to evaluate innovative energy concepts and components in energy systems. Experiments with different cooling systems in ECN's research dwellings are executed to evaluate their effective influence on both energy use and thermal comfort. Influence of inhabitants' behaviour is taken into account in these experiments. The thermal comfort is indicated by the Predicted Mean Vote (PMV) as defined by P.O. Fanger. For this paper, the results of measurements with a floor cooling and air cooling system are assessed. Effects on the PMV measured during experiments with the two different cooling systems will be presented.

  5. Total lactate dehydrogenase activity of tail muscle is not cold-adapted in nocturnal lizards from cool-temperate habitats.

    Science.gov (United States)

    Hare, K M; Miller, J H; Clark, A G; Daugherty, C H

    2005-12-01

    The dependence of metabolic processes on temperature constrains the behavior, physiology and ecology of many ectothermic animals. The evolution of nocturnality in lizards, especially in temperate regions, requires adaptations for activity at low temperatures when optimal body temperatures are unlikely to be obtained. We examined whether nocturnal lizards have cold-adapted lactate dehydrogenase (LDH). LDH was chosen as a representative metabolic enzyme. We measured LDH activity of tail muscle in six lizard species (n=123: three nocturnal, two diurnal and one crepuscular) between 5 and 35 degrees C and found no differences in LDH-specific activity or thermal sensitivity among the species. Similarly, the specific activity and thermal sensitivity of LDH were similar between skinks and geckos. Similar enzyme activities among nocturnal and diurnal lizards indicate that there is no selection of temperature specific LDH enzyme activity at any temperature. As many nocturnal lizards actively thermoregulate during the day, LDH may be adapted for a broad range of temperatures rather than adapted specifically for the low temperatures encountered when the animals are active. The total activity of LDH in tropical and temperate lizards is not cold-adapted. More data are required on biochemical adaptations and whole animal thermal preferences before trends can be established.

  6. Cool Stars and Space Weather

    CERN Document Server

    Vidotto, A A; Cameron, A C; Morin, J; Villadsen, J; Saar, S; Alvarado, J; Cohen, O; Holzwarth, V; Poppenhaeger, K; Reville, V

    2014-01-01

    Stellar flares, winds and coronal mass ejections form the space weather. They are signatures of the magnetic activity of cool stars and, since activity varies with age, mass and rotation, the space weather that extra-solar planets experience can be very different from the one encountered by the solar system planets. How do stellar activity and magnetism influence the space weather of exoplanets orbiting main-sequence stars? How do the environments surrounding exoplanets differ from those around the planets in our own solar system? How can the detailed knowledge acquired by the solar system community be applied in exoplanetary systems? How does space weather affect habitability? These were questions that were addressed in the splinter session "Cool stars and Space Weather", that took place on 9 Jun 2014, during the Cool Stars 18 meeting. In this paper, we present a summary of the contributions made to this session.

  7. Peltier-Cooled and Actively Quenched Operation of InGaAs/InP Avalanche Photodiodes as Photon Counters at a 1.55-mum Wavelength.

    Science.gov (United States)

    Prochazka, I

    2001-11-20

    The performance of commercially available InGaAs/InP avalanche photodiodes as single-photon detectors at a 1.55-mum wavelength has been investigated. A new active quenching and gating circuit, tailored for operation of these diodes at temperatures in the range from room temperature to -60 degrees C and achievable by means of thermoelectrical cooling, has been developed. Careful tuning of the diodes' operating conditions resulted in a significant reduction of afterpulsing effects; it permitted operation of the detectors with high repetition rates. A noise-equivalent power of 7 x 10(-16) W/Hz(1/2) was obtained at a 1.55-mum wavelength.

  8. Evaluation of finite element formulations for transient conduction forced-convection analysis. [of heat transfer for active cooling of hypersonic airframe and engine structures

    Science.gov (United States)

    Thornton, E. A.; Wieting, A. R.

    1979-01-01

    Conventional versus upwind convective finite elements, and lumped versus consistent formulations for practical conduction/forced convection analysis are evaluated on the basis of numerical studies, with finite element and finite difference lumped-parameter temperatures compared to closed-form analytical solutions for convection problems. Attention is given to two practical combined conduction and forced convection applications, stressing that the finite element method, showing superior accuracy, is competitive with the finite difference lumped-parameter method. Also considered are the computational time savings offered by the zero capacitance nodes procedure and comparative finite element and finite difference lumped-parameter computer times. The present study has reference to the design of actively cooled engine and airframe structures for hypersonic flight.

  9. Experimental study on a transpiration cooling thermal protection system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Transpiration cooling thermal protection systems (TPS) are investigated for potential applications in hypersonic and re-entry vehicles,which are subjected to the severe aerodynamic heating environment. In this paper a transpiration cooling thermal protection system was designed and manufactured,and an experiment platform with radiant heating at the bottom as heat source was developed. The cooling capacity of the transpiration cooling TPS was experimentally investigated. By combining transpiration cooling method with traditional TPS,the heat load capability of the TPS can be improved. The structure temperature with active cooling applied was much lower than that without active cooling applied under the same heat load as well as the heat load increased with active cooling than the one without active cooling for the same structure temperature. The experimental results showed that at 5800 s,the temperature of inner structure was 100°C with active cooling applied compared to 500°C without active cooling applied,then the temperature increased and reached to 360°C at 8300 s. Heat load of this transpiration cooling TPS can be increased by over 70% as compared to the passion one and the cooling capability of the transpiration TPS was about 1700 kJ/kg. The results can provide fundamental data for developing the transpiration cooling TPS.

  10. Effect of knee joint cooling on the electromyographic activity of lower extremity muscles during a plyometric exercise.

    Science.gov (United States)

    Schmid, Stefan; Moffat, Marilyn; Gutierrez, Gregory M

    2010-12-01

    During sporting events, injured athletes often return to competition after icing because of the reduction in pain. Although some controversy exists, several studies suggest that cryotherapy causes a decrease in muscle activity, which may lead to a higher risk of injury upon return to play. The purpose of this study was to investigate the effect of a 20-min knee joint cryotherapy application on the electromyographic activity of leg muscles during a single-leg drop jump in twenty healthy subjects, randomly assigned to an experimental and a control group. After the pre-tests, a crushed-ice bag was applied to the knee joint of the experimental group subjects for 20 min, while the control group subjects rested for 20 min. All subjects were retested immediately after this period and retested again after another 20 min of rest. Average electromyographic activity and ground contact time were calculated for the pre- and post-test sessions. Decreases in electromyographic activity of the lower extremity musculature were found in pre-activation, eccentric (braking), and concentric (push-off) phases immediately after the icing, and after 20 min of rest. The results lend support to the suggestion that cryotherapy during sporting events may place the individuals in a vulnerable position. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Liquid-Cooled Garment

    Science.gov (United States)

    1977-01-01

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

  12. Data center cooling system

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-17

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

  13. Stochastic cooling in RHIC

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-05-04

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

  14. Recent advances in laser cooling of solids

    Science.gov (United States)

    Nemova, Galina; Kashyap, Raman

    2013-10-01

    The recent achievements devoted to cooling of solids with a laser are presented in this paper. We discuss the latest results of traditional laser cooling of solids based on rare earth ions and new techniques based on colloidal lead-salt quantum dots doped in a glass host, laser cooling in Tm3+-doped oxy-fluoride glass ceramic. Relatively short (microsecond) lifetime of the excited level of the PbSe QDs compared to the millisecond lifetime of the excited level of RE ions allows an acceleration of the cooling process and provides an opportunity to use new materials with higher phonon energy as hosts, which are normally considered unsuitable for cooling with RE ions. Another new approach to the laser cooling problem based on super-radiance has been considered in this paper. The advantages of optical refrigeration with rare earth doped semiconductors, in which not only optically active electrons of the 4f shell but the valence and conduction bands of the host material are involved in cooling cycle is discussed. It is shown that involving the valence and conduction bands of the host in the cooling cycle allows the pump wavelength to be shorter than mean fluorescence wavelength. Raman laser cooling of solids as well as observation of spontaneous Brillouin cooling have been presented.

  15. Effects of Free-Hanging Horizontal Sound Absorbers on the Cooling Performance of Thermally Activated Building Systems

    DEFF Research Database (Denmark)

    Lacarte, Luis Marcos Domínguez; Rage, Nils; Kazanci, Ongun Berk

    2017-01-01

    Thermally Activated Building Systems (TABS) have proven to be an energy-efficient solution to provide buildings with an optimal indoor thermal environment. This solution uses the structure of the building to store heat, reduce the peak loads, and decrease the primary energy demand. TABS require t...... simulations using a new TRNSYS Type, the use of comfort ventilation has a considerable influence on the thermal conditions in the room; if the ventilation is removed, then the operative temperature increases by 1.8 K for a 60%-covered ceiling....

  16. System for cooling a cabinet

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to a cooling system comprising an active magnetic regenerator having a cold side and a hot side, a hot side heat exchanger connected to the hot side of the magnetic regenerator, one or more cold side heat exchangers, and a cold store reservoir comprising a volume...

  17. International Ventilation Cooling Application Database

    DEFF Research Database (Denmark)

    Holzer, Peter; Psomas, Theofanis Ch.; OSullivan, Paul

    2016-01-01

    The currently running International Energy Agency, Energy and Conservation in Buildings, Annex 62 Ventilative Cooling (VC) project, is coordinating research towards extended use of VC. Within this Annex 62 the joint research activity of International VC Application Database has been carried out, ...

  18. Technical Consultation of the International Space Station (ISS) Internal Active Thermal Control System (IATCS) Cooling Water Chemistry

    Science.gov (United States)

    Gentz, Steven J.; Rotter, Hank A.; Easton, Myriam; Lince, Jeffrey; Park, Woonsup; Stewart, Thomas; Speckman, Donna; Dexter, Stephen; Kelly, Robert

    2005-01-01

    The Internal Active Thermal Control System (IATCS) coolant exhibited unexpected chemical changes during the first year of on-orbit operation following the launch and activation in February 2001. The coolant pH dropped from 9.3 to below the minimum specification limit of 9.0, and re-equilibrated between 8.3 and 8.5. This drop in coolant pH was shown to be the result of permeation of CO2 from the cabin into the coolant via Teflon flexible hoses which created carbonic acid in the fluid. This unexpected diffusion was the result of having a cabin CO2 partial pressure higher than the ground partial pressure (average 4.0 mmHg vs. less than 0.2 mmHg). This drop in pH was followed by a concurrent increasing coolant nickel concentration. No other metal ions were observed in the coolant and based on previous tests, the source of nickel ion was thought to be the boron nickel (BNi) braze intermetallics used in the construction of HXs and cold plates. Specifically, BNi2 braze alloy was used for the IATCS IFHX and BNi3 braze alloy was used for the IATCS Airlock Servicing and Performance Checkout Unit (SPCU) HX and cold plates. Given the failure criticality of the HXs, a Corrosion Team was established by the IATCS CWG to determine the impact of the nickel corrosion on hardware performance life.

  19. Thermal-mechanical analysis of actively cooled folded core sandwich panels%主动冷却皱褶芯材夹层板的热力分析

    Institute of Scientific and Technical Information of China (English)

    周晨; 王志瑾; 支骄杨

    2014-01-01

    A multifunctional sandwich panel with folded cellular cores was proposed for actively cooled load-bearing components in aerospace thermal protection systems. Thermal-mechanical responses of V-type and M-type folded core sandwich panels subjected to forced convection using kerosene as a coolant were studied numerically. First, a 3D fluid-solid coupling model was established and the temperature fields of fluid and structure were computed using the conjugate heat transfer model. Subsequently, the thermal stress and deformation of structure were obtained via sequential coupling method. The results show that the heat transfer perform-ances of folded core sandwich panels are evidently improved through active cooling. The temperature increases along the flow direc-tion and presents a periodic fluctuation. Heat convection is reinforced due to the folds which also cause serious stress concentrations. Cell topology and geometric dimensions have certain influences on the heat transfer characteristics and thermal structural behavior of the active cooled panels. A M-type folded core sandwich panel is superior to a V-type one for a much less severe stress concentra-tion.%提出了一种将皱褶芯材夹层板与主动冷却相结合的承载-热防护一体化结构形式。以煤油为冷却液,在强迫对流条件下,采用数值仿真方法对V-型和M-型皱褶芯材夹层板的热力响应进行了研究。首先,建立了主动冷却皱褶芯材夹层板的三维流固耦合模型,应用共轭传热数值计算方法,求解获得了冷却液和结构的温度场;采用顺序耦合求解,得到了相应的结构应力场和变形场。结果表明,实施主动冷却后皱褶结构的换热性能明显提高;沿流向温度上升,并呈现周期性波动;结构的皱褶在加强对流换热的同时,也导致了应力集中。芯材胞元拓扑构型及几何尺寸对结构的换热性能和应力应变具有一定程度的影响。与V-型相比

  20. Laser cooling of solids

    OpenAIRE

    Nemova, Galina

    2009-01-01

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

  1. New Suns in the Cosmos. IV. The Multifractal Nature of Stellar Magnetic Activity in Kepler Cool Stars

    Science.gov (United States)

    de Freitas, D. B.; Nepomuceno, M. M. F.; Gomes de Souza, M.; Leão, I. C.; Das Chagas, M. L.; Costa, A. D.; Canto Martins, B. L.; De Medeiros, J. R.

    2017-07-01

    In the present study, we investigate the multifractal nature of a long-cadence time series observed by the Kepler mission for a sample of 34 M dwarf stars and the Sun in its active phase. Using the Multifractal Detrending Moving Average algorithm, which enables the detection of multifractality in nonstationary time series, we define a set of multifractal indices based on the multifractal spectrum profile as a measure of the level of stellar magnetic activity. This set of indices is given by the (A, {{Δ }}α , C, H)-quartet, where A, {{Δ }}α , and C are related to geometric features from the multifractal spectrum and the global Hurst exponent H describes the global structure and memorability of time series dynamics. As a test, we measure these indices and compare them with a magnetic index defined as S ph and verify the degree of correlation among them. First, we apply the Poincaré plot method and find a strong correlation between the index and one of the descriptors that emerges from this method. As a result, we find that this index is strongly correlated with long-term features of the signal. From the multifractal perspective, the index is also strongly linked to the geometric properties of the multifractal spectrum except for the H index. Furthermore, our results emphasize that the rotation period of stars is scaled by the H index, which is consistent with Skumanich’s relationship. Finally, our approach suggests that the H index may be related to the evolution of stellar angular momentum and a star’s magnetic properties.

  2. Stochastic cooling in RHIC

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-20

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

  3. Manufacturing and high heat-flux testing of brazed actively cooled mock-ups with Ti-doped graphite and CFC as plasma-facing materials

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Rosales, C; Ordas, N; Lopez-Galilea, I [CEIT and Tecnun (University of Navarra), 20018 San Sebastian (Spain); Pintsuk, G; Linke, J [Forschungszentrum Juelich GmbH, EURATOM Association, 52425 Juelich (Germany); Gualco, C; Grattarola, M; Mataloni, F [Ansaldo Ricerche S.p.A., I-16152 Genoa (Italy); Ramos Fernandez, J M; MartInez Escandell, M [Departamento de Quimica Inorganica, University of Alicante, E-03690 Alicante (Spain); Centeno, A; Blanco, C [Instituto Nacional del Carbon (CSIC), Apdo. 73, E-33080 Oviedo (Spain)], E-mail: cgrosales@ceit.es

    2009-12-15

    In the frame of the EU project ExtreMat new Ti-doped isotropic graphites and carbon fibre-reinforced carbons (CFCs) with high thermal conductivity and reduced chemical erosion were brazed to a CuCrZr heat-sink to produce flat-tile actively cooled mock-ups (MUs). Brazing was done using a low CTE interlayer to shift the stresses to the metal-metal interface. These MUs were exposed to high heat-fluxes in the electron beam facility JUDITH. Screening tests were conducted increasing the heat load stepwise up to 15 MW m{sup -2}, followed by 100 cycles at 15 MW m{sup -2}, subsequent screening up to 20 MW m{sup -2} and 100 cycles at 20 MW m{sup -2}. All MUs withstood screening at 15 MW m{sup -2} and most of them survived screening at 20 MW m{sup -2}. Ti-doped CFC MUs showed a significant improvement compared with the undoped reference CFC, surviving several cycles at 20 MW m{sup -2} on all tiles. One of the Ti-doped graphite MUs withstood 100 cycles at 20 MW m{sup -2} on one tile, representing a promising result.

  4. Cooling by Thermodynamic Induction

    Science.gov (United States)

    Patitsas, S. N.

    2017-03-01

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

  5. Cooling by Thermodynamic Induction

    Science.gov (United States)

    Patitsas, S. N.

    2016-11-01

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

  6. Radiant Floor Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2008-01-01

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

  7. Initial Cooling Experiment (ICE)

    CERN Multimedia

    Photographic Service

    1978-01-01

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

  8. Power electronics cooling apparatus

    Science.gov (United States)

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

    2000-01-01

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

  9. Design of a rapidly cooled cryogenic mirror

    Science.gov (United States)

    Plummer, Ron; Hsu, Ike

    1993-01-01

    The paper discusses the design, analysis, and testing of a rapidly cooled beryllium cryogenic mirror, which is the primary mirror in the four-element optical system for the Long Wavelength Infrared Advanced Technology Seeker. The mirror is shown to meet the requirement of five minutes for cooling to cryogenic operating temperature; it also maintains its optical figure and vacuum integrity and meets the nuclear specification. Results of a detailed thermal analysis on the mirror showed that, using nitrogen gas at 80 K as coolant, the front face of the mirror can be cooled from an initial temperature of 300 K to less than 90 K within five minutes. In a vacuum chamber, using liquid nitrogen as coolant, the mirror can be cooled to 80 K within 1.5 min. The mirror is well thermally insulated, so that it can be maintained at less than its operating temperature for a long time without active cooling.

  10. Study of the effect of finned tube adsorber on the performance of solar driven adsorption cooling machine using activated carbon-ammonia pair

    Energy Technology Data Exchange (ETDEWEB)

    Louajari, Mohamed; Mimet, Abdelaziz [Energetic Laboratory, Sciences Faculty, Abdelmalek Essaadi University, BP 2121, 93000 Tetouan (Morocco); Ouammi, Ahmed [Energetic Laboratory, Sciences Faculty, Abdelmalek Essaadi University, BP 2121, 93000 Tetouan (Morocco); Department of Communication, Computer and System Sciences (DIST), University of Genova, Genova (Italy)

    2011-03-15

    Solar refrigeration represents an important application of solar energy due to the excellent matching between the high sunshine and the refrigeration needs. Solar adsorption refrigeration devices are among the significant techniques used to meet the needs for cooling requirements. Several solar refrigeration systems have been proposed and are under development such as sorption systems including liquid/vapor, solid/vapor absorption, adsorption, vapor compression and others. The purpose of this paper is to identify the influence of a cylindrical adsorber on the performances of a solar adsorption refrigerating machine. The adsorber heated by solar energy contains an activated carbon-ammonia pair; it is composed by many cylindrical tubes welded using external fins. A model based on the conservation equations of energy and mass in the adsorber has been developed and well described. Using real solar irradiance data as well as many initial conditions, the model computes for each point and in the considered time interval during the day, the temperature, the adsorbed mass, the pressure inside the adsorber and the solar performance coefficient (COP). The results show that the optimal diameter of the adsorber with fins is greater than the one without fins. Moreover the mass cycled in the case of an adsorber equipped with external fins is more significant than the one without fins, and the maximal temperature reached in the adsorber with fins attains 97 C while in the adsorber without fins reaches 77 C. Thus, the performances of the solar adsorption refrigerating machine with an adsorber equipped with fins are higher than the machine without fins. (author)

  11. Measure Guideline: Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-01

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

  12. The final cool down

    CERN Multimedia

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

  13. Solar absorption cooling

    NARCIS (Netherlands)

    Kim, D.-S.

    2007-01-01

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

  14. Passive evaporative cooling

    NARCIS (Netherlands)

    Tzoulis, A.

    2011-01-01

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

  15. Data center cooling method

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-11

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

  16. Liquid Cooled Garments

    Science.gov (United States)

    1979-01-01

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

  17. Solar absorption cooling

    NARCIS (Netherlands)

    Kim, D.-S.

    2007-01-01

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

  18. Coherent electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko,V.

    2009-05-04

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

  19. Modeling gasodynamic vortex cooling

    Science.gov (United States)

    Allahverdyan, A. E.; Fauve, S.

    2017-08-01

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

  20. Hydronic rooftop cooling systems

    Science.gov (United States)

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

    2008-01-29

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

  1. INITIAL COOLING EXPERIMENT (ICE)

    CERN Multimedia

    1979-01-01

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

  2. INITIAL COOLING EXPERIMENT (ICE)

    CERN Multimedia

    1978-01-01

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

  3. Evaluation of the energy efficiency of active pass through wall cooling surface with phase change material in residential buildings combined with cistern cooling and operation optimization by development of suitable control strategies; Evaluierung der Energieeffizienz von aktiv durchstroemten Wandkuehlflaechen mit Phasenwechselmaterial in Wohngebaeuden in Kombination mit einer Zisternenkuehlung und Optimierung des Betriebes durch Entwicklung geeigneter Regelstrategien

    Energy Technology Data Exchange (ETDEWEB)

    Stoelzel, Christof [Variotec, Neumarkt (Germany); Kalz, Doreen; Wienold, Jan; Fischer, Martin [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany). Gruppe Solares Bauen

    2009-07-01

    This work introduces and evaluates a novel heating and cooling concept employing thermo-active building systems and environmental energy harnessed from 22-m{sup 3} rainwater cisterns for a 290-m{sup 2} low energy residential building in Germany. The building strives for a significantly reduced primary energy use with carefully coordinated measures such as high quality building envelope by means of vacuum insulated panels, supply and exhaust air system with heat recovery, reduced solar heat gains (solar shading), and the integration of thermal solar collectors and photovoltaic in the plant system. On this premise, a comprehensive long-term monitoring over the course of two years in high time resolution was carried out with an accompanying commissioning of the building performance. Measurements comprise the energy use for heating, cooling, and ventilation, as well as the auxiliary equipment, the performance of the environmental heat source/sink, thermal comfort, air quality, and local climatic site conditions. The analysis focuses on the performance and the efficiency of the rainwater cisterns as natural heat source and sink as well as the heat pump system. First, the paper discusses the performance of the thermo-active building systems, investigates the occupant thermal comfort, determines the efficiency of the heating/cooling system, and evaluates the total end and primary energy use of the building. Second, various operation and control strategies for the cooling plant are investigated by means of a validated building and plant model in the dynamic simulation environment TRNSYS. The optimization is carried out in terms of energy efficiency, occupant thermal comfort and the availability of the rainwater cisterns over the summer months. The central findings of the analysis of the energy and efficiency performance of the HVAC according to four defined balance boundaries are the following: Rainwater cistern as environmental source und sink: The energy balance of the

  4. Second sector cool down

    CERN Multimedia

    2007-01-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  6. Cool WISPs for stellar cooling excesses

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-15

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

  7. Cool WISPs for stellar cooling excesses

    CERN Document Server

    Giannotti, Maurizio; Redondo, Javier; Ringwald, Andreas

    2015-01-01

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

  8. Water-cooled electronics

    CERN Document Server

    Dumont, G; Righini, B

    2000-01-01

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

  9. Market assessment for active solar heating and cooling products. Category B: A survey of decision makers in the HVAC market place. Survey instruments

    Energy Technology Data Exchange (ETDEWEB)

    Lilien, G. L.; Johnston, P. E.

    1980-09-01

    Telephone screener questionnaires and mail-out questionnaires for marketing surveys for solar heating and cooling equipment are presented. Questionnaires are included for the residential segment, industrial segment, HVAC professionals segment, builder/developer segment, and the commercial segment. No results are reported. (WHK)

  10. Cooling Devices in Laser therapy.

    Science.gov (United States)

    Das, Anupam; Sarda, Aarti; De, Abhishek

    2016-01-01

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

  11. LHC cooling gains ground

    CERN Multimedia

    Huillet-Miraton Catherine

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

  12. Why Exercise Is Cool

    Science.gov (United States)

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

  13. Waveguide cooling system

    Science.gov (United States)

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

    1981-04-01

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

  14. Cooling of wood briquettes

    Directory of Open Access Journals (Sweden)

    Adžić Miroljub M.

    2013-01-01

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

  15. S'Cool LAB Summer CAMP 2017

    CERN Multimedia

    Woithe, Julia

    2017-01-01

    The S’Cool LAB Summer CAMP is an opportunity for high-school students (aged 16-19) from all around the world to spend 2 weeks exploring the fascinating world of particle physics. The 24 selected participants spend their summer at S’Cool LAB, CERN’s hands-on particle physics learning laboratory, for an epic programme of lectures and tutorials, team research projects, visits of CERN’s research installations, and social activities.

  16. Stacking with stochastic cooling

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-10-11

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

  17. Cooling of electronic equipment

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt

    2003-01-01

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

  18. Anomalous law of cooling

    OpenAIRE

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

    2014-01-01

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

  19. Cooling with Superfluid Helium

    CERN Document Server

    Lebrun, P

    2014-01-01

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

  20. Laser cooling of solids

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

  1. Stacking with Stochastic Cooling

    CERN Document Server

    Caspers, Friedhelm

    2004-01-01

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

  2. Alternative Room Cooling System

    Directory of Open Access Journals (Sweden)

    Md. Fazle Rabbi

    2015-06-01

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

  3. CO2 cooling for HEP experiments

    CERN Document Server

    Verlaat; Van Lysebetten, A

    2008-01-01

    The new generation silicon detectors require more efficient cooling of the front-end electronics and the silicon sensors themselves. To minimize reverse annealing of the silicon sensors the cooling temperatures need to be reduced. Other important requirements of the new generation cooling systems are a reduced mass and a maintenance free operation of the hardware inside the detector. Evaporative CO2 cooling systems are ideal for this purpose as they need smaller tubes than conventional systems. The heat transfer capability of evaporative CO2 is high. CO2 is used as cooling fluid for the LHCb-VELO and the AMS-Tracker cooling systems. A special method for the fluid circulation is developed at Nikhef to get a very stable temperature of both detectors without any active components like valves or heaters inside. This method is called 2-phase Accumulator Controlled Loop (2PACL) and is a good candidate technology for the design of the future cooling systems for the Atlas and CMS upgrades.

  4. Cooling of electronics in collider experiments

    Energy Technology Data Exchange (ETDEWEB)

    Richard P. Stanek et al.

    2003-11-07

    Proper cooling of detector electronics is critical to the successful operation of high-energy physics experiments. Collider experiments offer unique challenges based on their physical layouts and hermetic design. Cooling systems can be categorized by the type of detector with which they are associated, their primary mode of heat transfer, the choice of active cooling fluid, their heat removal capacity and the minimum temperature required. One of the more critical detector subsystems to require cooling is the silicon vertex detector, either pixel or strip sensors. A general design philosophy is presented along with a review of the important steps to include in the design process. Factors affecting the detector and cooling system design are categorized. A brief review of some existing and proposed cooling systems for silicon detectors is presented to help set the scale for the range of system designs. Fermilab operates two collider experiments, CDF & D0, both of which have silicon systems embedded in their detectors. A review of the existing silicon cooling system designs and operating experience is presented along with a list of lessons learned.

  5. Comparing Social Stories™ to Cool versus Not Cool

    Science.gov (United States)

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

    2016-01-01

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

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

    DEFF Research Database (Denmark)

    Bruun, Anders; Raptis, Dimitrios; Kjeldskov, Jesper

    2016-01-01

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

  7. Market assessment for active solar heating and cooling products. Category B: a survey of decision-makers in the HVAC marketplace. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    A comprehensive evaluation of the market for solar heating and cooling products for new and retrofit markets is reported. The emphasis is on the analysis of solar knowledge among HVAC decision makers and a comprehensive evaluation of their solar attitudes and behavior. The data from each of the following sectors are described and analyzed: residential consumers, organizational and manufacturing buildings, HVAC engineers and architects, builders/developers, and commercial/institutional segments. (MHR)

  8. High Performance Torso Cooling Garment

    Science.gov (United States)

    Conger, Bruce; Makinen, Janice

    2016-01-01

    The concept proposed in this paper is to improve thermal efficiencies of the liquid cooling and ventilation garment (LCVG) in the torso area, which could facilitate removal of LCVG tubing from the arms and legs, thereby increasing suited crew member mobility. EVA space suit mobility in micro-gravity is challenging, and it becomes even more challenging in the gravity of Mars. By using shaped water tubes that greatly increase the contact area with the skin in the torso region of the body, the heat transfer efficiency can be increased. This increase in efficiency could provide the required liquid cooling via torso tubing only; no arm or leg LCVG tubing would be required. Benefits of this approach include increased crewmember mobility, enhanced evaporation cooling, increased comfort during Mars EVA tasks, and easing of the overly dry condition in the helmet associated with the Advanced Extravehicular Mobility Unit (EMU) ventilation loop currently under development. This report describes analysis and test activities performed to evaluate the potential improvements to the thermal performance of the LCVG. Analyses evaluated potential tube shapes for improving the thermal performance of the LCVG. The analysis results fed into the selection of flat flow strips to improve thermal contact with the skin of the suited test subject. Testing of small segments was performed to compare thermal performance of the tubing approach of the current LCVG to the flat flow strips proposed as the new concept. Results of the testing is presented along with recommendations for future development of this new concept.

  9. The definition of cool

    Energy Technology Data Exchange (ETDEWEB)

    Nichiporuk, A.

    2005-05-01

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

  10. Aspects of Household Cooling Technology

    OpenAIRE

    Mrzyglod, Matthias; Holzer, Stefan

    2014-01-01

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

  11. Doppler cooling a microsphere

    CERN Document Server

    Barker, P F

    2010-01-01

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

  12. Natural radiative cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.

    1979-01-01

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

  13. Clean cooling; Saubere Kuehlung

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-07-01

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

  14. Monitoring Cray Cooling Systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    LI Yulong; WU Hong; ZHOU Feng; RONG Chengjun

    2016-01-01

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

  16. Anomalous law of cooling.

    Science.gov (United States)

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

    2015-03-14

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

  17. Anomalous law of cooling

    Science.gov (United States)

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

    2015-03-01

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

  18. Superconductor rotor cooling system

    Science.gov (United States)

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

    2002-01-01

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

  19. A Cool Emperor Penguin

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

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

  20. Rapid cooled lens cell

    Science.gov (United States)

    Stubbs, David M.; Hsu, Ike C.

    1991-12-01

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

  1. Gas cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1972-06-01

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

  2. Quantum thermodynamic cooling cycle

    CERN Document Server

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

    2001-01-01

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

  3. Cortical inactivation by cooling in small animals

    Directory of Open Access Journals (Sweden)

    Ben eCoomber

    2011-06-01

    Full Text Available Reversible inactivation of the cortex by surface cooling is a powerful method for studying the function of a particular area. Implanted cooling cryoloops have been used to study the role of individual cortical areas in auditory processing of awake-behaving cats. Cryoloops have also been used in rodents for reversible inactivation of the cortex, but recently there has been a concern that the cryoloop may also cool non-cortical structures either directly or via the perfusion of blood, cooled as it passed close to the cooling loop. In this study we have confirmed that the loop can inactivate most of the auditory cortex without causing a significant reduction in temperature of the auditory thalamus or other sub-cortical structures. We placed a cryoloop on the surface of the guinea pig cortex, cooled it to 2°C and measured thermal gradients across the neocortical surface. We found that the temperature dropped to 20-24°C among cells within a radius of about 2.5mm away from the loop. This temperature drop was sufficient to reduce activity of most cortical cells and led to the inactivation of almost the entire auditory region. When the temperature of thalamus, midbrain, and middle ear were measured directly during cortical cooling, there was a small drop in temperature (about 4°C but this was not sufficient to directly reduce neural activity. In an effort to visualise the extent of neural inactivation we measured the uptake of thallium ions following an intravenous injection. This confirmed that there was a large reduction of activity across much of the ipsilateral cortex and only a small reduction in subcortical structures.

  4. Liquid Cooling/Warming Garment

    Science.gov (United States)

    Koscheyev, Victor S.; Leon, Gloria R.; Dancisak, Michael J.

    2010-01-01

    The NASA liquid cooling/ventilating garment (LCVG) currently in use was developed over 40 years ago. With the commencement of a greater number of extra-vehicular activity (EVA) procedures with the construction of the International Space Station, problems of astronaut comfort, as well as the reduction of the consumption of energy, became more salient. A shortened liquid cooling/warming garment (SLCWG) has been developed based on physiological principles comparing the efficacy of heat transfer of different body zones; the capability of blood to deliver heat; individual muscle and fat body composition as a basis for individual thermal profiles to customize the zonal sections of the garment; and the development of shunts to minimize or redirect the cooling/warming loop for different environmental conditions, physical activity levels, and emergency situations. The SLCWG has been designed and completed, based on extensive testing in rest, exercise, and antiorthostatic conditions. It is more energy efficient than the LCVG currently used by NASA. The total length of tubing in the SLCWG is approximately 35 percent less and the weight decreased by 20 percent compared to the LCVG. The novel features of the innovation are: 1. The efficiency of the SLCWG to maintain thermal status under extreme changes in body surface temperatures while using significantly less tubing than the LCVG. 2. The construction of the garment based on physiological principles of heat transfer. 3. The identification of the body areas that are most efficient in heat transfer. 4. The inclusion of a hood as part of the garment. 5. The lesser consumption of energy.

  5. Measure Guideline: Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-01

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

  6. Cooling of Neutron Stars

    Directory of Open Access Journals (Sweden)

    Grigorian H.

    2010-10-01

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

  7. Elementary stochastic cooling

    Energy Technology Data Exchange (ETDEWEB)

    Tollestrup, A.V.; Dugan, G

    1983-12-01

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

  8. ELECTRON COOLING FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI,I.

    2001-05-13

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

  9. Comparison of different cooling regimes within a shortened liquid cooling/warming garment on physiological and psychological comfort during exercise

    Science.gov (United States)

    Leon, Gloria R.; Koscheyev, Victor S.; Coca, Aitor; List, Nathan

    2004-01-01

    The aim of this study was to compare the effectiveness of different cooling regime intensities to maintain physiological and subjective comfort during physical exertion levels comparable to that engaged in during extravehicular activities (EVA) in space. We studied eight subjects (six males, two females) donned in our newly developed physiologically based shortened liquid cooling/warming garment (SLCWG). Rigorous (condition 1) and mild (condition 2) water temperature cooling regimes were compared at physical exertion levels comparable to that performed during EVA to ascertain the effectiveness of a lesser intensity of cooling in maintaining thermal comfort, thus reducing energy consumption in the portable life support system. Exercise intensity was varied across stages of the session. Finger temperature, rectal temperature, and subjective perception of overall body and hand comfort were assessed. Finger temperature was significantly higher in the rigorous cooling condition and showed a consistent increase across exercise stages, likely due to the restriction of heat extraction because of the intensive cold. In the mild cooling condition, finger temperature exhibited an overall decline with cooling, indicating greater heat extraction from the body. Rectal temperature was not significantly different between conditions, and showed a steady increase over exercise stages in both rigorous and mild cooling conditions. Ratings of overall comfort were 30% higher (more positive) and more stable in mild cooling (p<0.001). The mild cooling regime was more effective than rigorous cooling in allowing the process of heat exchange to occur, thus maintaining thermal homeostasis and subjective comfort during physical exertion.

  10. Physiologic and Functional Responses of MS Patients to Body Cooling Using Commercially Available Cooling Garments

    Science.gov (United States)

    Ku, Yu-Tsuan E.; Montgomery, Leslie D.; Lee, Hank C.; Luna, Bernadette; Webbon, Bruce W.; Mead, Susan C. (Technical Monitor)

    1999-01-01

    Personal cooling systems are widely used in industrial and aerospace environments to alleviate thermal stress. Increasingly they are also used by heat sensitive multiple sclerosis (HSMS) patients to relieve symptoms and improve quality of life. There are a variety of cooling systems commercially available to the MS community. However, little information is available regarding the comparative physiological changes produced by routine operation of these various systems. The objective of this study was to document and compare the patient response to two passive cooling vests and one active cooling garment. The Life Enhancement Technology, Inc. (LET) lightweight active cooling vest with cap, the MicroClimate Systems (MCS) Change of Phase garment, and the Steele Vest were each used to cool 13 male and 13 female MS subjects (31 to 67 yr.) in this study. The subjects, seated in an upright position at normal room temperature (approximately 22 C), were tested with one of the cooling garments. Oral, fight and left ear temperatures were logged manually every 5 min. An-n, leg, chest and rectal temperatures; heart rate; and respiration were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. Each subject was given a series of subjective and objective evaluation tests before and after cooling. The LET and Steele vests test groups had similar, significant (P less than 0.01) cooling effects on oral and ear canal temperature, which decreased approximately 0.4 C, and 0.3 C, respectively. Core temperature increased (N.S.) with all three vests during cooling. The LET vest produced the coldest (P less than 0.01) skin temperature. Overall, the LET vest provided the most improvement on subjective and objective performance measures. These results show that the garment configurations tested do not elicit a similar thermal response in all MS patients. Cooling with the LET active garment configuration resulted in the lowest body temperatures for the MS subjects; cooling with

  11. Development of Cooling Process Control Technique in Hot Strip Mill

    Institute of Scientific and Technical Information of China (English)

    HAN Bin; LIU Xiang-hua; WANG Guo-dong; SHE Guang-fu

    2005-01-01

    In order to ensure required mechanical properties of steel strip, various innovations in the cooling process control on the run-out table of a hot strip mill were actively promoted. The recent progress of process mathematical model and the new cooling strategy and equipment were discussed. The computer control system of high performance was introduced. The development trend in cooling process control was given.

  12. Cooling systems for ultra-high temperature turbines.

    Science.gov (United States)

    Yoshida, T

    2001-05-01

    This paper describes an introduction of research and development activities on steam cooling in gas turbines at elevated temperature of 1500 C and 1700 C level, partially including those on water cooling. Descriptions of a new cooling system that employs heat pipes are also made. From the view point of heat transfer, its promising applicability is shown with experimental data and engine performance numerical evaluation.

  13. Sorption cooling: a valid extension to passive cooling

    NARCIS (Netherlands)

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

    2008-01-01

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

  14. Comments on Ionization Cooling Channel Characteristics

    CERN Document Server

    Neuffer, David

    2013-01-01

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

  15. Comments on Ionization Cooling Channel Characteristics

    OpenAIRE

    Neuffer, David

    2013-01-01

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

  16. STOCHASTIC COOLING FOR BUNCHED BEAMS.

    Energy Technology Data Exchange (ETDEWEB)

    BLASKIEWICZ, M.

    2005-05-16

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

  17. ALP hints from cooling anomalies

    CERN Document Server

    Giannotti, Maurizio

    2015-01-01

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

  18. Cooling devices in laser therapy

    Directory of Open Access Journals (Sweden)

    Anupam Das

    2016-01-01

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

  19. Self pumping magnetic cooling

    Science.gov (United States)

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

    2017-01-01

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

  20. Cooled particle accelerator target

    Science.gov (United States)

    Degtiarenko, Pavel V.

    2005-06-14

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

  1. Water Cooled Mirror Design

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-30

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

  2. Magnetic entropy and cooling

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  3. Cooling Floor AC Systems

    Science.gov (United States)

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

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

  4. Heating, ventilation and cooling

    CSIR Research Space (South Africa)

    Osburn, L

    2009-02-01

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

  5. Cooled Ion Frequency Standard.

    Science.gov (United States)

    2014-09-26

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

  6. Electron Cooling of RHIC

    CERN Document Server

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

    2005-01-01

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

  7. Low mass integrated cooling

    CERN Document Server

    Mapelli, Alessandro

    2014-01-01

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

  8. Simulation of Desiccant Cooling

    Directory of Open Access Journals (Sweden)

    Kamaruddin A.

    2017-06-01

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

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

    Science.gov (United States)

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

    2012-02-01

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

  10. Effect of Half Time Cooling on Thermoregulatory Responses and Soccer-Specific Performance Tests

    Directory of Open Access Journals (Sweden)

    Yang Zhang

    2014-03-01

    Full Text Available This study examined two active coolings (forearm and hand cooling, and neck cooling during a simulated half-time recovery on thermoregulatory responses and subsequent soccer-specific exercise performance. Following a 45-min treadmill run in the heat, participants (N=7 undertook 15-min recovery with either passive cooling, forearm and hand cooling, or neck cooling in a simulated cooled locker room environment. After the recovery, participants performed a 6×15-m sprint test and Yo-Yo Intermittent Recovery Level 1 test (YYIR1 in a temperate environment. During the 15-min recovery, rectal temperature fell significantly (p<0.05. Neither active coolings induced further reduction in rectal temperature compared to passive cooling. No effect of active coolings was found in repeated sprint test. However, neck cooling reduced (p<0.05 the thermal sensation (TS compared to passive cooling during the 15-min recovery. Active coolings attenuated (p<0.05 the sweat rate compared to passive cooling: 1.2±0.3 l•h-1 vs. 0.8±0.1 l•h-1 vs. 0.8±0.3 l•h-1, for passive cooling, forearm and hand cooling, and neck cooling, respectively. For passive cooling, elevated sweat rate resulted in higher (p<0.05 dehydration (2.1±0.3% compared to neck cooling (1.5±0.3% and forearm and hand cooling (1.4±0.3%. YYIR1 was improved (p<0.05 following forearm and hand cooling (869±320 m and neck cooling (814±328 m compared to passive cooling (654±311 m. Neck cooling (4.6±0.6 reduced (p=0.03 the session TS compared to passive cooling (5.3±0.5. These results suggest that active coolings effectively improved comfort and sweating response, which delayed exercise-heat induced performance diminish during a second bout of exercise.

  11. Microprocessor Control For Liquid-Cooled Garment

    Science.gov (United States)

    Weaver, Charles S.

    1990-01-01

    Automatic control system maintains temperature of water-cooled garment within comfort zone while wearer's level of physical activity varies. Uncomfortable overshoots and undershoots of temperature eliminated. Designed for use in space suit, adaptable to other protective garments and to enclosed environments operating according to similar principles.

  12. Cooling lubricants; Kuehlschmierstoffe

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

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

  13. Use of fluorocarbons in the cooling of LHC experiments

    CERN Document Server

    Pimenta dos Santos, M

    2003-01-01

    Perfluorochemicals sold by 3M under the trade name 3M Fluorinert Electronic Liquids have been used for many years as heat transfer media in a variety of industries. The suitability of these liquids for the cooling of LHC experiment originates from their high dielectric strength as well as from their chemical stability under ionizing radiation. The Fluorinerts are clear, colorless, non-flammable with low toxicity and low corrosiveness. Additionally, they offer low global waming potential – GWP – and zero ozone-depletion potential – ODP. Some examples of fluorinert application in the cooling of LHC experiments will be presented : (a) the ATLAS Inner detector C3F8 evaporative cooling system (b) the ATLAS TRF C6F14 monophase cooling system and (c) the ALICE SPD “active heat pipe” C4F10 evaporative cooling system. A brief comparison of evaporative and monophase cooling systems will be outlined.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

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

  15. Effects of Water Quality on Activity of Biofouling in Recirculating Cooling Water System%循环冷却水水质对生物粘泥活性的影响研究

    Institute of Scientific and Technical Information of China (English)

    马涛; 赵朝成; 刘芳; 张培; 夏璐

    2011-01-01

    受补充水水质的影响,循环冷却水水质会在一定范围内波动,为此考察了营养物质(BOD5、TP、NH4+-N)、颗粒物质(CaCO3)、无机离子(Ca2+、Mg2+、Na+、Fe3+)对循环水中生物粘泥活性的影响.研究结果表明,循环冷却水水质对生物粘泥的活性有较大影响,当BOD5≤25 mg/L、NH4+-N<5 mg/L、TP≤1 mg/L时,可将粘泥活性控制在较低水平.在低营养水平条件下,分别维持CaCO3<40 mg/L、Ca2+<100 mg/L、Mg2+≤100 mg/L、Na+<50 mg/L、Fe3+<0.5 mg/L时,可有效抑制粘泥活性,控制粘泥中细菌的生长繁殖.%Due to the influence of make-up water quality, the water quality of recirculating cooling water system would fluctuate within a certain range. So the effects of necessary nutrients ( BOD5 , TP and NH4+ - N), suspended particles (CaCO3) and inorganic ion (Ca2 + , Mg2+ , Na + and Fe3 + ) content on activity of biofouling in recirculating cooling water system were investigated. The results show that the water quality of recirculating cooling water system has significant effect on the activity of biofouling. When BOD5 and TP are equal to or less than 25 mg/L and 1 mg/L respectively, NH4+ - N is less than 5 mg/L,the activity of biofouling can be controlled at a low level. Under low nutrient conditions, keeping CaCO3,Ca2+ , Na + , Fe3+ and Mg2+ at less than 40 mg/L, 100 mg/L, 50 mg/L, 0.5 mg/L and equal to or less than 100 mg/L respectively can effectively inhibit the activity of biofouling and control the growth and reproduction of bacteria in biofouling.

  16. Performance of extravehicular activity space suit: a combined system of cooling, heating and power%舱外航天服冷热电一体化系统性能分析

    Institute of Scientific and Technical Information of China (English)

    周国栋; 高峰; 李运泽; 王胜男; 周航

    2013-01-01

    A combined cooling, heating and power (CCHP) system for extravehicular activity (EVA) space suit is proposed in this paper. The CCHP system mainly consists of a proton exchange membrane fuel cell (PEMFC), a heat driving cooling device, a metal hydride hydrogen storage device and a radiator. A Power Supply Priority scheme is proposed for the CCHP system in order to match both the power supply and the cooling request. Based on the PSP scheme, the operation state parameters and the mass of the CCHP system are calculated under a typical working condition. Influences of the PEMFC's working temperature, the current density and the pressure on the system mass and the expendable material loss are analyzed. The results show that the mass of the EVA space suit CCHP system is acceptable, and the expendable material loss is much less than that of the water sublimator/storage battery scheme. Lowering the PEMFC working temperature and pressure, or raising the PEMFC's current density, would lead to a lighter system and less expendable material loss.%文章提出了一种舱外航天服冷热电一体化(Combined Cooling-Heating-Power,CCHP)系统,该系统的主要组件有质子交换膜燃料电池、热驱制冷装置、金属氢化物储氢装置和辐射器等.在冷热电一体化系统的冷电匹配方法上提出了“以电定冷”方案,按照该方案计算了一组典型工况下系统的工作状态,分析了燃料电池的工作温度、工作电流密度和工作压力对系统质量和消耗性工质损失的影响.结果表明,该舱外航天服冷热电一体化系统在质量大小方面可以接受,在消耗性工质损失方面比水升华器冷源/蓄电池电源方案小得多;且降低燃料电池工作温度和压力、增大燃料电池工作电流密度,均能够减小系统质量、降低系统消耗性工质损失.

  17. Study of the activity of quaternary ammonium compounds in the mitigation of biofouling in heat exchangers-condensers cooled by seawater.

    Science.gov (United States)

    Trueba, Alfredo; Otero, Félix M; González, José A; Vega, Luis M; García, Sergio

    2013-01-01

    The effectiveness of two quaternary ammonium compounds (QACs) (non-oxidising biocides) to reduce the growth of biofilm adhering to the tubes of a heat exchanger-condenser cooled by seawater was evaluated. Their effectiveness was compared to that of a conventional oxidising biocide (sodium hypochlorite [NaOCl]) under the same testing conditions. Each biocide was applied intermittently (6 h on, 6 h off) in a first shock stage (1.5 ppm over 8 days) and a second stabilising stage (0.5 ppm over 20 days). The results showed that the antifouling effectiveness of the first of the QACs (fifth generation) was comparable to that shown by the oxidising power of NaOCl. Although the reaction time was longer than that of NaOCl, both the compounds removed the biofilm, and the tube was practically restored to its clean condition. Treatment with the second of the QACs (fourth generation) allowed for the stabilisation of biofilm growth, but not for its removal. Ecotoxicology studies classified the QACs as environmentally harmless under the testing conditions.

  18. Monolithically Peltier-cooled laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hava, S.; Hunsperger, R.G.; Sequeira, H.B.

    1984-04-01

    A new method of cooling a GaAs/GaAlAs laser in an optical integrated circuit or on a discrete chip, by adding an integral thermoelectric (Peltier) cooling and heat spreading device to the laser, is presented. This cooling both reduces and stabilizes the laser junction temperature to minimize such deleterious effects as wavelength drift due to heating. A unified description of the electrical and thermal properties of a monolithic semiconductor mesa structure is given. Here it is shown that an improvement in thermal characteristics is obtained by depositing a relatively thick metallic layer, and by using this layer as a part of an active Peltier structure. Experimental results reveal a 14-percent increase in emitted power (external quantum efficiency) due to passive heat spreading and a further 8-percent if its Peltier cooler is operated. Fabrication techniques used to obtain devices exhibiting the above performance characteristics are given. 21 references.

  19. Black holes, cooling flows and galaxy formation.

    Science.gov (United States)

    Peacock, J A

    2005-03-15

    Central black holes in galaxies are now well established as a ubiquitous phenomenon, and this fact is important for theories of cosmological structure formation. Merging of galaxy haloes must preserve the proportionality between black hole mass and baryonic mass; the way in which this happens may help solve difficulties with existing ing models of galaxy formation, which suffer from excessive cooling and thus over- produce stars. Feedback from active nuclei may be the missing piece of the puzzle, regulating galaxy-scale cooling flows. Such a process now seems to be observed in cluster-scale cooling flows, where dissipation of sound waves generated by radio lobes can plausibly balance the energy lost in X-rays, at least in a time-averaged sense.

  20. Laser Cooling of Molecular Anions

    CERN Document Server

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

    2015-01-01

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

  1. Laser cooling of molecular anions.

    Science.gov (United States)

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

    2015-05-29

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

  2. Global Cooling: Policies to Cool the World and Offset Global Warming from CO2 Using Reflective Roofs and Pavements

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Levinson, Ronnen; Rosenfeld, Arthur; Elliot, Matthew

    2009-08-28

    Increasing the solar reflectance of the urban surface reduce its solar heat gain, lowers its temperatures, and decreases its outflow of thermal infrared radiation into the atmosphere. This process of 'negative radiative forcing' can help counter the effects of global warming. In addition, cool roofs reduce cooling-energy use in air conditioned buildings and increase comfort in unconditioned buildings; and cool roofs and cool pavements mitigate summer urban heat islands, improving outdoor air quality and comfort. Installing cool roofs and cool pavements in cities worldwide is a compelling win-win-win activity that can be undertaken immediately, outside of international negotiations to cap CO{sub 2} emissions. We propose an international campaign to use solar reflective materials when roofs and pavements are built or resurfaced in temperate and tropical regions.

  3. Process integration: Cooling water systems design

    CSIR Research Space (South Africa)

    Gololo, KV

    2010-10-01

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

  4. Cooling water systems design using process integration

    CSIR Research Space (South Africa)

    Gololo, KV

    2010-09-01

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

  5. Solar heating and cooling.

    Science.gov (United States)

    Duffie, J A; Beckman, W A

    1976-01-16

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

  6. Laser Cooling of Solids

    Science.gov (United States)

    2009-01-01

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

  7. International Ventilation Cooling Application Database

    DEFF Research Database (Denmark)

    Holzer, Peter; Psomas, Theofanis Ch.; OSullivan, Paul

    2016-01-01

    The currently running International Energy Agency, Energy and Conservation in Buildings, Annex 62 Ventilative Cooling (VC) project, is coordinating research towards extended use of VC. Within this Annex 62 the joint research activity of International VC Application Database has been carried out...... European and international Low Energy buildings. Still it’s not really widespread. Obstacles are challenges as regards noise, dust, weather and burglary, proving the research efforts of the Annex being necessary. The VC database forms a worthwhile basis for both dissemination and further research targets......., systematically investigating the distribution of technologies and strategies within VC. The database is structured as both a ticking-list-like building-spreadsheet and a collection of building-datasheets. The content of both closely follows Annex 62 State-Of-The- Art-Report. The database has been filled, based...

  8. Cooling, AGN Feedback and Star Formation in Simulated Cool-Core Galaxy Clusters

    CERN Document Server

    Li, Yuan; Ruszkowski, Mateusz; Voit, G Mark; O'Shea, Brian W; Donahue, Megan

    2015-01-01

    Numerical simulations of active galactic nuclei (AGN) feedback in cool-core galaxy clusters have successfully avoided classical cooling flows, but often produce too much cold gas. We perform adaptive mesh simulations that include momentum-driven AGN feedback, self-gravity, star formation and stellar feedback, focusing on the interplay between cooling, AGN heating and star formation in an isolated cool-core cluster. Cold clumps triggered by AGN jets and turbulence form filamentary structures tens of kpc long. This cold gas feeds both star formation and the supermassive black hole (SMBH), triggering an AGN outburst that increases the entropy of the ICM and reduces its cooling rate. Within 1-2 Gyr, star formation completely consumes the cold gas, leading to a brief shutoff of the AGN. The ICM quickly cools and redevelops multiphase gas, followed by another cycle of star formation/AGN outburst. Within 6.5 Gyr, we observe three such cycles. There is good agreement between our simulated cluster and the observations...

  9. Optical cavity cooling of mechanical modes of a semiconductor nanomembrane

    DEFF Research Database (Denmark)

    Usami, Koji; Naesby, A.; Bagci, Tolga

    2012-01-01

    . The resultant photo-induced rigidity is large and a mode temperature cooled from room temperature down to 4 K is realized with 50 μW of light and a cavity finesse of just 10. Thermal stress due to non-radiative relaxation of the electron–hole pairs is the primary cause of the cooling. We also analyse...... an alternative cooling mechanism that is a result of electronic stress via the deformation potential, and outline future directions for cavity optomechanics with optically active semiconductors.......-quality-factor and optically active semiconductor nanomembrane. The cooling is a result of electron–hole generation by cavity photons. Consequently, the cooling factor depends on the optical wavelength, varies drastically in the vicinity of the semiconductor bandgap, and follows the excitonic absorption behaviour...

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

    Institute of Scientific and Technical Information of China (English)

    Dongliang QUAN; Songling LIU; Jianghai LI; Gaowen LIU

    2005-01-01

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

  11. Influence of the irradiation time on the activity of decay products during the cooling. Case: Mo-98 {yields} Mo-99 {yields} Tc-99m; Influencia del tiempo de irradiacion en la actividad de los productos de decaimiento durante el enfriamiento. Caso: Mo-98 {yields} Mo-99 {yields} Tc-99m

    Energy Technology Data Exchange (ETDEWEB)

    Reyes J, J.L.; Ruiz C, M.A.; Alanis M, J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    In this work the behavior of the activity in the cooling time of Mo-99, Tc-99 and Tc-99m obtained by Neutron activation of natural Mo is described. The analytical development is based on the application of the Laplace transform for resolving the balance equations. (Author)

  12. Optical stochastic cooling in Tevatron

    CERN Document Server

    Lebedev, V

    2012-01-01

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

  13. Electron Cooling Experiments in CSR

    CERN Document Server

    Xiaodong, Yang

    2011-01-01

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

  14. Radiative cooling for thermophotovoltaic systems

    Science.gov (United States)

    Zhou, Zhiguang; Sun, Xingshu; Bermel, Peter

    2016-09-01

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

  15. To Be Cool or Uncool?

    Institute of Scientific and Technical Information of China (English)

    袁会珍

    2007-01-01

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

  16. Electron cooling experiments in CSR

    Institute of Scientific and Technical Information of China (English)

    PARKHOMCHUK; Vasily; REVA; Vladimir

    2011-01-01

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

  17. Workshop 4 Converter cooling & recuperation

    Science.gov (United States)

    Iles, Peter; Hindman, Don

    1995-01-01

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

  18. Stochastic cooling technology at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-10-11

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

  19. Direct cooled power electronics substrate

    Science.gov (United States)

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

    2010-09-14

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

  20. Cooling clothing utilizing water evaporation

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  1. Regeneratively Cooled Porous Media Jacket

    Science.gov (United States)

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

    2013-01-01

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

  2. Fluid cooled electrical assembly

    Science.gov (United States)

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

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

  3. ATLAS' major cooling project

    CERN Multimedia

    2005-01-01

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

  4. Air cooled absorption chillers for solar cooling applications

    Science.gov (United States)

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

    1982-03-01

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

  5. Cooling Torsional Nanomechanical Vibration by Spin-Orbit Interactions

    Institute of Scientific and Technical Information of China (English)

    ZHAO Nan; ZHOU Duan-Lu; ZHU Jia-Lin

    2008-01-01

    We propose and study a spin-orbit interaction based mechanism to actively cool down the torsional vibration of a nanomechanical resonator made by semiconductor materials. We show that the spin-orbit interactions of electrons can induce a coherent coupling between the electron spins and the torsional modes of nanomechanical vibration. This coupling leads to an active cooling for the torsional modes through the dynamical thermalization of the resonator by the spin ensemble.

  6. Plasma chemistry of the sealed-off slab CO laser active medium pumped by radio-frequency discharge with liquid-nitrogen-cooled electrodes

    Science.gov (United States)

    Ionin, A. A.; Kozlov, A. Yu.; Seleznev, L. V.; Sinitsyn, D. V.

    2017-09-01

    The long-term time behavior of the output power of a sealed-off cryogenic slab CO laser pumped by a repetitively pulsed RF discharge and operating on the overtone (λ = 2.6-3.5 μm) vibrational-rotational transitions of the CO molecule was studied experimentally. It is shown that adding of an anomalously large amount of oxygen (up to 50% with respect to the CO concentration) to the initial gas mixture CO : He = 1 : 10 leads to a manyfold (by several tens of times) increase in the duration of the laser operating cycle (until lasing failure due to the degradation of the active medium). In this case, the laser life-time without replacement of the active medium reaches 105-106 pulses. Using various diagnostics (including luminescence spectroscopy and IR and UV absorption spectroscopy), regularities in the time-behavior of the concentrations of the main component of the active medium (CO molecules) and the products of plasmachemical reactions (O3, CO2) generated in the discharge gap during the laser operating cycle are revealed. Time correlation between the characteristics of the active medium and the laser output power are analyzed. A phenomenological approach to describing the entirety of plasmachemical, purely chemical, gas-dynamic, and diffusion processes determining the behavior of the laser output characteristics throughout the laser operating cycle is offered.

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

    Science.gov (United States)

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

    2012-01-01

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

  8. LS1 Report: Summer cool down

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    As the final LS1 activities are carried out in the machine, teams have been cooling down the accelerator sector by sector in preparation for beams.   The third sector of the LHC to be cooled down - sector 1-2 - has seen the process begin this week. During the cool-down phase, survey teams are measuring and smoothing (or realigning) the magnets at cold. By the end of August, five sectors of the machine will be in the process of cooling down, with one (sector 6-7) at cold. The LHC Access Safety System (LASS) is now being commissioned, and will be validated during the DSO tests at the beginning of October. As teams consolidate the modifications made to LASS during the shutdown, many points were closed for testing purposes. The CSCM (copper stabiliser continuity measurement) tests have been completed in the first sector (6-7) and no defect has been found. These results will be presented to the LHC Machine Committee next week. CSCM tests will start in the second sector in mid-August. Following many...

  9. Newton's Law of Cooling Revisited

    Science.gov (United States)

    Vollmer, M.

    2009-01-01

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

  10. Dialogues in the COOL Project

    NARCIS (Netherlands)

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

    2013-01-01

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

  11. Be Cool, Man! / Jevgeni Levik

    Index Scriptorium Estoniae

    Levik, Jevgeni

    2005-01-01

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

  12. Temperature initiated passive cooling system

    Science.gov (United States)

    Forsberg, Charles W.

    1994-01-01

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

  13. Be Cool, Man! / Jevgeni Levik

    Index Scriptorium Estoniae

    Levik, Jevgeni

    2005-01-01

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

  14. Dew Point Evaporative Comfort Cooling

    Science.gov (United States)

    2012-11-01

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

  15. Triatomic molecules laser-cooled

    Science.gov (United States)

    2017-06-01

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

  16. A novel electronic cooling concept

    Science.gov (United States)

    Ponnappan, R.; Beam, J. E.

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

  17. Laser cooling to quantum degeneracy.

    Science.gov (United States)

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

    2013-06-28

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

  18. Cooling off with physics

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-08-01

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

  19. Hydraulic analysis of the Wendelstein 7-X cooling loops

    Energy Technology Data Exchange (ETDEWEB)

    Smirnow, M., E-mail: michael.smirnow@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Orozco, G.; Boscary, J. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Peacock, A. [European Commission c/o Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany)

    2013-10-15

    Highlights: • A hydraulic simulation model of the W7-X cooling loops and plasma facing components. • CFD analysis of orifice components. • Optimization and flow balancing of cooling loops. -- Abstract: Actively water cooled in vessel components (IVC) are required for the long pulse operation of the stellarator Wendelstein 7-X (W7-X). In total, the cooling pipes have a length of about 4.5 km, supplying the coolant via 304 cooling circuits for the IVC. Within each cooling loop, the IVC are organized mostly in parallel. A homogeneous flow through all branches or at least the minimum specified flow in all of the branches of a circuit is crucial for the IVC to withstand the loading conditions. A detailed hydraulic simulation model of the W7-X cooling loops was built with the commercial code Flowmaster, which is a 1-D computational fluid dynamics software. In order to handle the huge amount of pipe-work data that had to be modelled, a pre- and post-processing macro was developed to transfer the 3D Catia V5 CAD model to the 1-D piping model. Within this model, the hydraulic characteristics of different types of first wall components were simulated, and compared with their pressure drop measurements. As a result of this work, the need for optimization of some cooling loops has been identified and feasible modified solutions were selected.

  20. Simulating the Cooling Flow of Cool-Core Clusters

    CERN Document Server

    Li, Yuan

    2011-01-01

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

  1. Cooling Does Not Affect Knee Proprioception

    OpenAIRE

    Ozmun, John C.; Thieme, Heather A.; Ingersoll, Christopher D; Knight, Kenneth L

    1996-01-01

    The effect of cooling on proprioception of the knee has not been studied extensively. In this study, we investigated the movement reproduction (timing and accuracy) aspect of proprioception. Subjects were tested under two conditions: a 20-minute application of ice and control. Proprioceptive accuracy and timing were measured by passively moving the knee, then comparing the subject's active reproduction of the passive movement. Subjects were blindfolded, then tested in three sectors of the kne...

  2. Cooling Acoustic Transcucer with Heat Pipes

    Science.gov (United States)

    2009-07-19

    pipes. [0013] Most transducer packages involve a stack of active ceramic. A Tonpilz transducer 10 in the prior art, as depicted in FIG. 1...identical or corresponding parts throughout the several views and wherein: [0023] FIG. 1 is a prior art depiction of a Tonpilz transducer design...Distribution is unlimited 20090916027 Attorney Docket No. 97001 COOLING ACOUSTIC TRANSDUCER WITH HEAT PIPES STATEMENT OF GOVERNMENT INTEREST [0001

  3. 46 CFR 153.432 - Cooling systems.

    Science.gov (United States)

    2010-10-01

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

  4. How to get cool in the heat: comparing analytic models of halo gas cooling with EAGLE

    CERN Document Server

    Stevens, Adam R H; Contreras, Sergio; Croton, Darren J; Padilla, Nelson D; Schaller, Matthieu; Schaye, Joop; Theuns, Tom

    2016-01-01

    We use the hydrodynamic, cosmological EAGLE simulations to investigate how hot gas in haloes condenses to form and grow galaxies. We select haloes from the simulations that are actively cooling and study the temperature, distribution, and metallicity of their hot, cold, and transitioning `cooling' gas, placing these in context of semi-analytic models. Our selection criteria lead us to focus on Milky Way-like haloes. We find the hot-gas density profiles of the haloes form a progressively stronger core over time, the nature of which can be captured by a beta profile that has a simple dependence on redshift. In contrast, the hot gas that actually cools is broadly consistent with a singular isothermal sphere. We find that cooling gas carries a few times the specific angular momentum of the halo and is offset in spin direction from the rest of the hot gas. The gas loses ~60% of its specific angular momentum during the cooling process, generally remaining greater than that of the halo, and is better aligned with th...

  5. Convective cooling of photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  6. Central cooling: absorptive chillers

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1977-08-01

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

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

    Science.gov (United States)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1936-01-01

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

  8. Small Liquid Metal Cooled Reactor Safety Study

    Energy Technology Data Exchange (ETDEWEB)

    Minato, A; Ueda, N; Wade, D; Greenspan, E; Brown, N

    2005-11-02

    The Small Liquid Metal Cooled Reactor Safety Study documents results from activities conducted under Small Liquid Metal Fast Reactor Coordination Program (SLMFR-CP) Agreement, January 2004, between the Central Research Institute of the Electric Power Industry (CRIEPI) of Japan and the Lawrence Livermore National Laboratory (LLNL)[1]. Evaluations were completed on topics that are important to the safety of small sodium cooled and lead alloy cooled reactors. CRIEPI investigated approaches for evaluating postulated severe accidents using the CANIS computer code. The methods being developed are improvements on codes such as SAS 4A used in the US to analyze sodium cooled reactors and they depend on calibration using safety testing of metal fuel that has been completed in the TREAT facility. The 4S and the small lead cooled reactors in the US are being designed to preclude core disruption from all mechanistic scenarios, including selected unprotected transients. However, postulated core disruption is being evaluated to support the risk analysis. Argonne National Laboratory and the University of California Berkeley also supported LLNL with evaluation of cores with small positive void worth and core designs that would limit void worth. Assessments were also completed for lead cooled reactors in the following areas: (1) continuing operations with cladding failure, (2) large bubbles passing through the core and (3) recommendations concerning reflector control. The design approach used in the US emphasizes reducing the reactivity in the control mechanisms with core designs that have essentially no, or a very small, reactivity change over the core life. This leads to some positive void worth in the core that is not considered to be safety problem because of the inability to identify scenarios that would lead to voiding of lead. It is also believed that the void worth will not dominate the severe accident analysis. The approach used by 4S requires negative void worth throughout

  9. Cooling-sensitive TRPM8 is thermostat of skin temperature against cooling.

    Directory of Open Access Journals (Sweden)

    Koji Tajino

    Full Text Available We have shown that cutaneous cooling-sensitive receptors can work as thermostats of skin temperature against cooling. However, molecule of the thermostat is not known. Here, we studied whether cooling-sensitive TRPM8 channels act as thermostats. TRPM8 in HEK293 cells generated output (y when temperature (T was below threshold of 28.4°C. Output (y is given by two equations: At T >28.4°C, y = 0; At T <28.4°C, y  =  -k(T - 28.4°C. These equations show that TRPM8 is directional comparator to elicits output (y depending on negative value of thermal difference (ΔT  =  T - 28.4°C. If negative ΔT-dependent output of TRPM8 in the skin induces responses to warm the skin for minimizing ΔT recursively, TRPM8 acts as thermostats against cooling. With TRPM8-deficient mice, we explored whether TRPM8 induces responses to warm the skin against cooling. In behavioral regulation, when room temperature was 10°C, TRPM8 induced behavior to move to heated floor (35°C for warming the sole skin. In autonomic regulation, TRPM8 induced activities of thermogenic brown adipose tissue (BAT against cooling. When menthol was applied to the whole trunk skin at neutral room temperature (27°C, TRPM8 induced a rise in core temperature, which warmed the trunk skin slightly. In contrast, when room was cooled from 27 to 10°C, TRPM8 induced a small rise in core temperature, but skin temperature was severely reduced in both TRPM8-deficient and wild-type mice by a large heat leak to the surroundings. This shows that TRPM8-driven endothermic system is less effective for maintenance of skin temperature against cooling. In conclusion, we found that TRPM8 is molecule of thermostat of skin temperature against cooling.

  10. Cooling arrangement for a tapered turbine blade

    Science.gov (United States)

    Liang, George

    2010-07-27

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

  11. New Approaches to Final Cooling

    CERN Document Server

    Neuffer, David

    2015-01-01

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

  12. Cooling towers principles and practice

    CERN Document Server

    Hill, G B; Osborn, Peter D

    1990-01-01

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

  13. CLIC inner detectors cooling simulations

    CERN Document Server

    Duarte Ramos, F.; Villarejo Bermudez, M.

    2014-01-01

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

  14. Preliminary design package for prototype solar heating and cooling systems

    Science.gov (United States)

    1978-01-01

    A summary is given of the preliminary analysis and design activity on solar heating and cooling systems. The analysis was made without site specific data other than weather; therefore, the results indicate performance expected under these special conditions. Major items include a market analysis, design approaches, trade studies and other special data required to evaluate the preliminary analysis and design. The program calls for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test. Two heating and six heating and cooling units will be delivered for Single Family Residences, Multiple-family Residences and commercial applications.

  15. Proposal for Laser Cooling of Complex Polyatomic Molecules.

    Science.gov (United States)

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

    2016-11-18

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

  16. Mini-Membrane Evaporator for Contingency Spacesuit Cooling

    Science.gov (United States)

    Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Petty, Brian; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

    2015-01-01

    The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only approximately 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini-ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

  17. Moderate Cortical Cooling Eliminates Thalamocortical Silent States during Slow Oscillation.

    Science.gov (United States)

    Sheroziya, Maxim; Timofeev, Igor

    2015-09-23

    Reduction in temperature depolarizes neurons by a partial closure of potassium channels but decreases the vesicle release probability within synapses. Compared with cooling, neuromodulators produce qualitatively similar effects on intrinsic neuronal properties and synapses in the cortex. We used this similarity of neuronal action in ketamine-xylazine-anesthetized mice and non-anesthetized mice to manipulate the thalamocortical activity. We recorded cortical electroencephalogram/local field potential (LFP) activity and intracellular activities from the somatosensory thalamus in control conditions, during cortical cooling and on rewarming. In the deeply anesthetized mice, moderate cortical cooling was characterized by reversible disruption of the thalamocortical slow-wave pattern rhythmicity and the appearance of fast LFP spikes, with frequencies ranging from 6 to 9 Hz. These LFP spikes were correlated with the rhythmic IPSP activities recorded within the thalamic ventral posterior medial neurons and with depolarizing events in the posterior nucleus neurons. Similar cooling of the cortex during light anesthesia rapidly and reversibly eliminated thalamocortical silent states and evoked thalamocortical persistent activity; conversely, mild heating increased thalamocortical slow-wave rhythmicity. In the non-anesthetized head-restrained mice, cooling also prevented the generation of thalamocortical silent states. We conclude that moderate cortical cooling might be used to manipulate slow-wave network activity and induce neuromodulator-independent transition to activated states. Significance statement: In this study, we demonstrate that moderate local cortical cooling of lightly anesthetized or naturally sleeping mice disrupts thalamocortical slow oscillation and induces the activated local field potential pattern. Mild heating has the opposite effect; it increases the rhythmicity of thalamocortical slow oscillation. Our results demonstrate that slow oscillation can be

  18. Passive low energy cooling of buildings

    CERN Document Server

    Givoni, Baruch

    1994-01-01

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

  19. Cool Sooting Flames of Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    Z.A. MANSUROV

    2001-01-01

    This paper presents the study of polycyclic aromatic hydrocarbons (PAH) and paramagnetism of soot particles sampled from cool sooting flames of methane and propane in a separately-heated two-sectional reactor under atmospheric pressure at the reactor temperatures of 670-1170 K. The temperature profiles of the flames were studied. The sampling was carried out with a quartz sampler and the samples were frozen with liquid nitrogen. A number of polyaromatic hydrocarbons such as pyrene, fluoranthene, coronene, anthanthrene, 1,12-benzperylene,were identified by spectroscopic methods in the extract of soot. The processes of soot formation at methaneoxygen mixture combustion in the electric field with applied potential changed from 0 to 2,2 kV at different polarity of electrodes have been investigated. It has been stated that at the electrical field application, an increase in soot particle sizes and soot yield occurs; besides, at the application of the field, speeding up the positively charged particles, the interplanar distance decreases. On the basis of investigation of soot particles paramagnetism, it was shown that initially soot particles have high carcinogetic activity and pollute the environment owing to a rapid decrease of the number of these radical centers. The reduction of the radical concentration is connected with radical recombination on soot.

  20. Sympathetic laser cooling of graphene with Casimir-Polder forces

    Science.gov (United States)

    Ribeiro, Sofia; Terças, Hugo

    2016-10-01

    We propose a scheme to actively cool the fundamental flexural (out-of-plane) mode of a graphene sheet via vacuum forces. Our setup consists of a cold-atom cloud placed close to a graphene sheet at distances of a few micrometers. The atoms couple to the graphene membrane via Casimir-Polder forces. By deriving a self-consistent set of equations governing the dynamics of the atomic gas and the flexural modes of the graphene, we show it is possible to cool graphene from room temperatures by actively (laser) cooling an atomic gas. By choosing the right set of experimental parameters we are able to cool a graphene sheet down to ˜60 μ K .

  1. Compressor bleed cooling fluid feed system

    Science.gov (United States)

    Donahoo, Eric E; Ross, Christopher W

    2014-11-25

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

  2. Helium-cooling in fusion power plants

    Energy Technology Data Exchange (ETDEWEB)

    Wong, C.P.C.; Baxi, C.B.; Hamilton, C.J.; Schleicher, R.W.; Streckert, H.

    1994-11-01

    This paper reviews different helium-cooled first wall and blanket designs; and compares the selection of structural materials. The authors found that the solid breeder, SiC-composite material option generates the lowest amount of induced radioactivity and afterheat and has the highest temperature capability. When combined with the direct cycle gas turbine system, it has the potential to be the most economical fusion system and can compete with advanced fission reactors. When compared to martensitic steel and V-alloy, SiC-composite is the least developed of these three structural materials, a focused development effort will be needed. Fundamental research has begun in addressing the issues of optimized composite materials, irradiation effects, leak tightness and low activation braze materials. Development of helium-cooled high heat flux components and further development of the direct cycle gas turbine system will also be needed.

  3. Solar heating cooling. Preparation of possible participation in IEA, Solar Heating Cooling Task 25; Solvarmedrevet koeling. Forberedelse af evt. deltagelse i IEA, Solar Heating Cooling Task 25

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    everybody are connected to the electric power network and where the effect tax, except in certain German areas, is low. Should a European market for solar cooling be developed a conscious policy is required, which rewards effect savings. Because of the non-existing domestic market and the diffuse European market possibilities active Danish participation in IEA Task 25 it is not recommended. (EHS)

  4. Cooling Technology for Electronic Computers

    Science.gov (United States)

    Nakayama, Wataru

    The rapid growth of data processing speed in computers has been sustained by the advances in cooling technology. This article first presents a review of the published data of heat loads in recent Japanese large-scale computers. The survey indicates that, since around 1980, the high-level integration of microelectronic circuits has brought about almost four fold increase in the power dissipation from logic chips. The integration also has invited the evolutions of multichip modules and new schemes of electronic interconnections. Forced convection air-cooling and liquid cooling coupled with thermal connectors are discussed with reference to the designs employed in actual computers. More advanced cooling schemes are also discussed. Finally, the importance of thermal environmental control of computer rooms is emphasized.

  5. Cooled Ceramic Turbine Vane Project

    Data.gov (United States)

    National Aeronautics and Space Administration — N&R Engineering will investigate the feasibility of cooled ceramics, such as ceramic matrix composite (CMC) turbine blade concepts that can decrease specific...

  6. Surface-induced evaporative cooling

    Institute of Scientific and Technical Information of China (English)

    Ke Min; Yan Bo; Cheng Feng; Wang Yu-Zhu

    2009-01-01

    The effects of surface-induced evaporative cooling on an atom chip are investigated. The evolutions of temperature, number and phase-space density of the atom cloud are measured when the atom cloud is brought close to the surface. Rapid decrease of the temperature and number of the atoms is found when the atom-surface distance is < 100 μm. A gain of about a factor of five on the phase-space density is obtained. It is found that the efficiency of the surface-induced evaporative cooling depends on the atom-surface distance and the shape of the evaporative trap. When the atoms are moved very close to the surface, severe heating is observed, which dominates when the holding time is > 8 ms. It is important that the surface-induced evaporative cooling offers novel possibilities for the realization of a continuous condensation, where a spatially varying evaporative cooling is required.

  7. S'Cool LAB Summer CAMP 2017 at CERN

    CERN Multimedia

    2017-01-01

    The S’Cool LAB Summer CAMP is an opportunity for high-school students (aged 16-19) from all around the world to spend 2 weeks exploring the fascinating world of particle physics. The 24 selected participants spend their summer at S’Cool LAB, CERN’s hands-on particle physics learning laboratory, for an epic programme of lectures and tutorials, team research projects, visits of CERN’s research installations, and social activities.

  8. RF system concepts for a muon cooling experiment

    Energy Technology Data Exchange (ETDEWEB)

    Turner, W.C.; Corlett, J.N.; Li, D. [Lawrence Berkeley National Lab., CA (United States); Moretti, A. [Fermi National Accelerator Lab., Batavia, IL (United States); Kirk, H.G.; Palmer, R.B.; Zhao, Y. [Brookhaven National Lab., Upton, NY (United States)

    1998-06-01

    The feasibility of muon colliders for high energy physics experiments has been under intensive study for the past few years and recent activity has focused on defining an R and D program that would answer the critical issues. An especially critical issue is developing practical means of cooling the phase space of the muons once they have been produced and captured in a solenoidal magnetic transport channel. Concepts for the rf accelerating cavities of a muon cooling experiment are discussed.

  9. Turbine Blade Cooling System Optimization

    OpenAIRE

    GIRARDEAU, Julian; PAILHES, Jérôme; SEBASTIAN, Patrick; PARDO, Frédéric; Nadeau, Jean-Pierre

    2013-01-01

    The authors wish to thank turbine designers from TURBOMECA SAFRAN Group.; International audience; Designing high performance cooling systems suitable for preserving the service lifetime of nozzle guide vanes of turboshaft engines leads to significant aerodynamic losses. These losses jeopardize the performance of the whole engine. In the same time, a low efficiency cooling system may affect the costs of maintenance repair and overhaul of the engine as component life decreases. Consequently, de...

  10. DETERMINATION OF RADIATOR COOLING SURFACE

    Directory of Open Access Journals (Sweden)

    A. I. Yakubovich

    2009-01-01

    Full Text Available The paper proposes a methodology for calculation of a radiator cooling surface with due account of heat transfer non-uniformity on depth of its core. Calculation of radiator cooling surfaces of «Belarus-1221» and «Belarus-3022» tractors has been carried out in the paper. The paper also advances standard size series of radiators for powerful «Belarus» tractor type.

  11. Quantum limit of photothermal cooling

    CERN Document Server

    De Liberato, Simone; Nori, Franco

    2010-01-01

    We study the problem of cooling a mechanical oscillator using the photothermal (bolometric) force. Contrary to previous attempts to model this system, we take into account the noise effects due to the granular nature of photon absorption. This allows us to tackle the cooling problem down to the noise dominated regime and to find reasonable estimates for the lowest achievable phonon occupation in the cantilever.

  12. Cooling Shelf For Electronic Equipment

    Science.gov (United States)

    Tanzer, Herbert J.

    1989-01-01

    Heat-pipe action cools and maintains electronics at nearly constant temperature. System designed to control temperatures of spacecraft shelves or baseplates by combining honeycomb sandwich panel with reservoir of noncondensable gas and processing resulting device as variable-conductance heat pipe. Device provides flat surface for mounting heat-dissipating electronics that is effectively cooled and maintained at nearly constant temperature. Potentially useful in freeze drying, refrigeration, and air conditioning.

  13. Energy Efficient Electronics Cooling Project

    Energy Technology Data Exchange (ETDEWEB)

    Steve O' Shaughnessey; Tim Louvar; Mike Trumbower; Jessica Hunnicutt; Neil Myers

    2012-02-17

    Parker Precision Cooling Business Unit was awarded a Department of Energy grant (DE-EE0000412) to support the DOE-ITP goal of reducing industrial energy intensity and GHG emissions. The project proposed by Precision Cooling was to accelerate the development of a cooling technology for high heat generating electronics components. These components are specifically related to power electronics found in power drives focused on the inverter, converter and transformer modules. The proposed cooling system was expected to simultaneously remove heat from all three of the major modules listed above, while remaining dielectric under all operating conditions. Development of the cooling system to meet specific customer's requirements and constraints not only required a robust system design, but also new components to support long system functionality. Components requiring further development and testing during this project included pumps, fluid couplings, cold plates and condensers. All four of these major categories of components are required in every Precision Cooling system. Not only was design a key area of focus, but the process for manufacturing these components had to be determined and proven through the system development.

  14. Microtextured Surfaces for Turbine Blade Impingement Cooling

    Science.gov (United States)

    Fryer, Jack

    2014-01-01

    Gas turbine engine technology is constantly challenged to operate at higher combustor outlet temperatures. In a modern gas turbine engine, these temperatures can exceed the blade and disk material limits by 600 F or more, necessitating both internal and film cooling schemes in addition to the use of thermal barrier coatings. Internal convective cooling is inadequate in many blade locations, and both internal and film cooling approaches can lead to significant performance penalties in the engine. Micro Cooling Concepts, Inc., has developed a turbine blade cooling concept that provides enhanced internal impingement cooling effectiveness via the use of microstructured impingement surfaces. These surfaces significantly increase the cooling capability of the impinging flow, as compared to a conventional untextured surface. This approach can be combined with microchannel cooling and external film cooling to tailor the cooling capability per the external heating profile. The cooling system then can be optimized to minimize impact on engine performance.

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

    CERN Document Server

    Pizzolato, F; Pizzolato, Fabio; Soker, Noam

    2004-01-01

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

  16. Development of the electron cooling simulation program for JLEIC

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, He [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Chen, Jie [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Huang, He [Old Dominion Univ., Norfolk, VA (United States); Luo, Li-Shi [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    In the JLab Electron Ion Collider (JLEIC) project the traditional electron cooling technique is used to reduce the ion beam emittance at the booster ring, and to compensate the intrabeam scattering effect and maintain the ion beam emittance during collision at the collider ring. A new electron cooling process simulation program has been developed to fulfill the requirements of the JLEIC electron cooler design. The new program allows the users to calculate the electron cooling rate and simulate the cooling process with either DC or bunched electron beam to cool either coasting or bunched ion beam. It has been benchmarked with BETACOOL in aspect of accuracy and efficiency. In typical electron cooling process of JLEIC, the two programs agree very well and we have seen a significant improvement of computational speed using the new one. Being adaptive to the modern multicore hardware makes it possible to further enhance the efficiency for computationally intensive problems. The new program is being actively used in the electron cooling study and cooler design for JLEIC. We will present our models and some simulation results in this paper.

  17. Actively Cooled Ceramic Composite Nozzle Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase I Project demonstrated the capability of the Pyrowave? manufacturing process to produce fiber-reinforced ceramics (FRCs) with integral metal features, such...

  18. Actively Cooled Ceramic Composite Nozzle Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For Next Generation Launch Vehicles (NGLV), Either a Rocket-based or Turbine-based Combined Cycle (RBCC or TBCC) engine will power the Next Generation Launch Vehicle...

  19. Thermomechanical characterization of actively cooled vascularized composites

    OpenAIRE

    Coppola, Anthony; Sottos, Nancy; White, Scott

    2014-01-01

    Fiber-reinforced polymer matrix composites (PMC) possess outstanding structural properties, including high strength and stiffness, low density, and highly tunable properties. However, their application is limited where elevated temperature stability is required, e.g., during high-speed flight, in engine exhaust systems, or as support for high-power electronics. Mechanical properties are greatly reduced above the glass transition temperature of the matrix and thermal decomposition will occur a...

  20. Biomedical Use of Aerospace Personal Cooling Garments

    Science.gov (United States)

    Webbon, Bruce W.; Montgomery, Leslie D.; Callaway, Robert K.

    1994-01-01

    Personal thermoregulatory systems are required during extravehicular activity (EVA) to remove the metabolic heat generated by the suited astronaut. The Extravehicular and Protective Systems (STE) Branch of NASA Ames Research Center has developed advanced concepts or liquid cooling garments for both industrial and biomedical applications for the past 25 years. Examples of this work include: (1) liquid cooled helmets for helicopter pilots and race car drivers; (2) vests for fire and mine rescue personnel; (3) bras to increase the definition of tumors during thermography; (4) lower body garments for young women with erythomelaigia; and (5) whole body garments used by patients with multiple sclerosis (MS). The benefits of the biomedical application of artificial thermoregulation received national attention through two recent events: (1) the liquid-cooled garment technology was inducted into the United States Space Foundation's Space Technology Hall of Fame (1993); and (2) NASA has signed a joint Memorandum of Understanding with the Multiple Sclerosis Association (1994) to share this technology for use with MS patient treatment. The STE Branch is currently pursuing a program to refine thermoregulatory design in light of recent technology developments that might be applicable for use by several medical patient populations. Projects have been initiated to apply thermoregulatory technology for the treatment and/or rehabilitation of patients with spinal cord injuries, multiple sclerosis, migraine headaches, and to help prevent the loss of hair during chemotherapy.

  1. King of Cool

    Science.gov (United States)

    Freado, Mark; Van Bockern, Steve

    2010-01-01

    Many teenagers get involved in criminal activity. This tendency is so pervasive that psychologist Terrie Moffitt, one of the world's leading experts on the development of antisocial behavior, has described delinquent behavior as a normal part of teenager life (Scott & Steinberg, 2008). Adults, even those in the justice system, are often at a loss…

  2. Cool Cow Quiz.

    Science.gov (United States)

    DeRosa, Bill

    1988-01-01

    Provides a game to help develop the skill of estimating and making educated guesses. Uses facts about cows to explain some problems associated with the dairy industry. Includes cards and rules for playing, class adaptation procedures, follow-up activities, and availability of background information on humane concerns. (RT)

  3. Bunched Beam Cooling in the Fermilab Recycler

    CERN Document Server

    Neuffer, David V; Burov, Alexey; Nagaitsev, Sergei

    2005-01-01

    Stochastic cooling with bunched beam in a linear bucket has been obtained and implemented operationally in the fermilab recycler. In this implementation the particle bunch length is much greater than the cooling system wavelengths. The simultaneous longitudinal bunching enables cooling to much smaller longitudinal emittances than the coasting beam or barrier bucket system. Characteristics and limitations of bunched beam stochastic cooling are discussed.

  4. A new Newton's law of cooling?

    Science.gov (United States)

    Kleiber, M

    1972-12-22

    Several physiologists confuse Fourier's law of animal heat flow with Newton's law of cooling. A critique of this error in 1932 remained ineffective. In 1969 Molnar tested Newton's cooling law. In 1971 Strunk found Newtonian cooling unrealistic for animals. Unfortunately, he called the Fourier formulation of animal heat flow, requiring post-Newtonian observations, a "contemporary Newtonian law of cooling."

  5. 14 CFR 25.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 25.1043 Section 25.1043... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Cooling § 25.1043 Cooling tests. (a) General. Compliance... during the cooling tests must be the minimum grade approved for the engines, and the mixture...

  6. 14 CFR 27.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 27.1043 Section 27.1043... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Cooling § 27.1043 Cooling tests. (a) General. For the tests... during the cooling tests must be of the minimum grade approved for the engines, and the mixture...

  7. 14 CFR 29.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 29.1043 Section 29.1043... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Cooling § 29.1043 Cooling tests. (a) General. For the... (a)(1) of this section may exceed established limits. (3) The fuel used during the cooling tests...

  8. 14 CFR 29.908 - Cooling fans.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling fans. 29.908 Section 29.908... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant General § 29.908 Cooling fans. For cooling fans that are a part of a powerplant installation the following apply: (a) Category A. For cooling fans...

  9. 14 CFR 23.1043 - Cooling tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling tests. 23.1043 Section 23.1043... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Cooling § 23.1043 Cooling... established limits. (3) The fuel used during the cooling tests must be of the minimum grade approved for...

  10. Impingement jet cooling in gas turbines

    CERN Document Server

    Amano, R S

    2014-01-01

    Due to the requirement for enhanced cooling technologies on modern gas turbine engines, advanced research and development has had to take place in field of thermal engineering. Impingement jet cooling is one of the most effective in terms of cooling, manufacturability and cost. This is the first to book to focus on impingement cooling alone.

  11. COOL CORE CLUSTERS FROM COSMOLOGICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rasia, E.; Borgani, S.; Murante, G.; Planelles, S.; Biffi, V.; Granato, G. L. [INAF, Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131, Trieste (Italy); Beck, A. M.; Steinborn, L. K.; Dolag, K. [Universitäts-Sternwarte München, Scheinerstr.1, D-81679 München (Germany); Ragone-Figueroa, C., E-mail: rasia@oats.inaf.it [Instituto de Astronomá Teórica y Experimental (IATE), Consejo Nacional de Investigaciones Cientiíficas y Técnicas de la República Argentina (CONICET), Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, X5000BGR, Córdoba (Argentina)

    2015-11-01

    We present results obtained from a set of cosmological hydrodynamic simulations of galaxy clusters, aimed at comparing predictions with observational data on the diversity between cool-core (CC) and non-cool-core (NCC) clusters. Our simulations include the effects of stellar and active galactic nucleus (AGN) feedback and are based on an improved version of the smoothed particle hydrodynamics code GADGET-3, which ameliorates gas mixing and better captures gas-dynamical instabilities by including a suitable artificial thermal diffusion. In this Letter, we focus our analysis on the entropy profiles, the primary diagnostic we used to classify the degree of cool-coreness of clusters, and the iron profiles. In keeping with observations, our simulated clusters display a variety of behaviors in entropy profiles: they range from steadily decreasing profiles at small radii, characteristic of CC systems, to nearly flat core isentropic profiles, characteristic of NCC systems. Using observational criteria to distinguish between the two classes of objects, we find that they occur in similar proportions in both simulations and observations. Furthermore, we also find that simulated CC clusters have profiles of iron abundance that are steeper than those of NCC clusters, which is also in agreement with observational results. We show that the capability of our simulations to generate a realistic CC structure in the cluster population is due to AGN feedback and artificial thermal diffusion: their combined action allows us to naturally distribute the energy extracted from super-massive black holes and to compensate for the radiative losses of low-entropy gas with short cooling time residing in the cluster core.

  12. On the Cooling of the Neutron Star in Cassiopeia A

    CERN Document Server

    Blaschke, D; Voskresensky, D N; Weber, F

    2011-01-01

    We demonstrate that the high-quality cooling data observed for the young neutron star in the supernova remnant Cassiopeia A over the past 10 years--as well as all other reliably known temperature data of neutron stars--can be comfortably explained within the "nuclear medium cooling" scenario. The cooling rates of this scenario account for medium-modified one-pion exchange in dense matter and polarization effects in the pair-breaking formations of superfluid neutrons and protons. Crucial for the successful description of the observed data is a substantial reduction of the thermal conductivity, resulting from a suppression of both the electron and nucleon contributions to it by medium effects. We also find that possibly in as little as about ten years of continued observation, the data may tell whether or not fast cooling processes are active in this neutron star.

  13. A somatosensory circuit for cooling perception in mice.

    Science.gov (United States)

    Milenkovic, Nevena; Zhao, Wen-Jie; Walcher, Jan; Albert, Tobias; Siemens, Jan; Lewin, Gary R; Poulet, James F A

    2014-11-01

    The temperature of an object provides important somatosensory information for animals performing tactile tasks. Humans can perceive skin cooling of less than one degree, but the sensory afferents and central circuits that they engage to enable the perception of surface temperature are poorly understood. To address these questions, we examined the perception of glabrous skin cooling in mice. We found that mice were also capable of perceiving small amplitude skin cooling and that primary somatosensory (S1) cortical neurons were required for cooling perception. Moreover, the absence of the menthol-gated transient receptor potential melastatin 8 ion channel in sensory afferent fibers eliminated the ability to perceive cold and the corresponding activation of S1 neurons. Our results identify parts of a neural circuit underlying cold perception in mice and provide a new model system for the analysis of thermal processing and perception and multimodal integration.

  14. Cooling Load Estimation in the Building Based On Heat Sources

    Science.gov (United States)

    Chairani; Sulistyo, S.; Widyawan

    2017-05-01

    Heating, ventilation and air conditioning (HVAC) is the largest source of energy consumption. In this research, we discuss cooling load in the room by considering the different heat source and the number of occupancy. Energy cooling load is affected by external and internal heat sources. External cooling load in this discussion include convection outdoor/exterior using the DOE-2 algorithm, calculation of heat using Thermal Analysis Research Program (TARP), and Conduction Transfer Function (CTF). The internal cooling load is calculated based on the activity of the occupants in the office, a number of occupants, heat gain from lighting, and heat gain from electrics equipment. Weather data used is Surakarta weather and design day used is Jakarta design day. We use the ASHRAE standard for building materials and the metabolic of occupants while on the activity. The results show that the number of occupancies have an influence of cooling load. A large number of occupancy will cause the cooling load is great as well.

  15. New cooling regulation technology of secondary cooling station in DCS

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Yan, Jun-wei; Zhu, Dong-sheng; Liu, Fei-long; Lei, Jun-xi [The Key Lab of Enhanced Heat Transfer and Energy Conservation of Ministry of Education, School of Chemical and Energy Engineering, South China University of Technology, Guangzhou 510641 (China); Liang, Lie-quan [The Key Lab of E-Commerce Market Application Technology of Guangdong Province, Guangdong University of Business Studies, Guangzhou 510320 (China)

    2008-07-01

    In this paper, a kind of new control technology of secondary cooling station (constant flow rate/variable temperature difference) in district cooling system (DCS) is proposed in view of serial consequences including low efficiency and high operating cost caused by low temperature of supply water in DCS. This technology has been applied in DCS of Guangzhou University City. The result has already indicated that such technology can increase the supply and return temperatures of buildings, return water temperature of primary side in the plate heat exchanger unit, moreover, the efficiency of both the chiller and the whole system are improved significantly. (author)

  16. Cooling Efficiency of Laminar Cooling System for Plate Mill

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dian-hua; WANG Bing-xing; ZHOU Na; YU Ming; WANG Jun

    2008-01-01

    Heat transfer was researched from a perspective of the industry application.On the basis of the first law of thermodynamics,the cooling efficiency was deduced from the change of enthalpy inside hot plate.The relationship between the cooling efficiency and its influencing parameters was regressed from plenty of data collected from the worksite and discussed in detail.The temperature profiles resulting from the online model and the model modified by regressed formulas were presented and compared.The results indicated that the control accuracy of the modified model was increased obviously.

  17. Personal cooling apparatus and method

    Energy Technology Data Exchange (ETDEWEB)

    Siman-Tov, Moshe (Knoxville, TN); Crabtree, Jerry Allen (Knoxville, TN)

    2001-01-01

    A portable lightweight cooling apparatus for cooling a human body is disclosed, having a channeled sheet which absorbs sweat and/or evaporative liquid, a layer of highly conductive fibers adjacent the channeled sheet; and, an air-moving device for moving air through the channeled sheet, wherein the layer of fibers redistributes heat uniformly across the object being cooled, while the air moving within the channeled sheet evaporates sweat and/or other evaporative liquid, absorbs evaporated moisture and the uniformly distributed heat generated by the human body, and discharges them into the environment. Also disclosed is a method for removing heat generated by the human body, comprising the steps of providing a garment to be placed in thermal communication with the body; placing a layer of highly conductive fibers within the garment adjacent the body for uniformly distributing the heat generated by the body; attaching an air-moving device in communication with the garment for forcing air into the garment; removably positioning an exchangeable heat sink in communication with the air-moving device for cooling the air prior to the air entering the garment; and, equipping the garment with a channeled sheet in communication with the air-moving device so that air can be directed into the channeled sheet and adjacent the layer of fibers to expell heat and moisture from the body by the air being directed out of the channeled sheet and into the environment. The cooling system may be configured to operate in both sealed and unsealed garments.

  18. Oxygen Absorption in Cooling Flows.

    Science.gov (United States)

    Buote

    2000-04-01

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

  19. Axion Cooling of Neutron Stars

    CERN Document Server

    Sedrakian, Armen

    2015-01-01

    Cooling simulations of neutron stars and their comparison with the data from thermally emitting X-ray sources puts constraints on the properties of axions, and by extension of any light pseudo-scalar dark matter particles, whose existence has been postulated to solve the strong-CP problem of QCD. We incorporate the axion emission by pair-breaking and formation processes by $S$- and $P$-wave nucleonic condensates in a benchmark code for cooling simulations as well as provide fit formulae for the rates of these processes. Axion cooling of neutron stars has been simulated for 24 models covering the mass range 1 to 1.8 solar masses, featuring non-accreted iron and accreted light element envelopes, and a range of nucleon-axion coupling. The models are based on an equation state predicting conservative physics of superdense nuclear matter that does not allow for onset of fast cooling processes induced by phase transitions to non-nucleonic forms of matter or high proton concentration. The cooling tracks in the tempe...

  20. Quench cooling under reduced gravity

    CERN Document Server

    Chatain, D; Nikolayev, V S; Beysens, D

    2013-01-01

    We report the quench cooling experiments performed with liquid O2 under different levels of gravity simulated with the magnetic gravity compensation. A copper disk is quenched from 270K to 90K. It is found that the cooling time in microgravity is very long in comparison with any other gravity level. This phenomenon is explained by the isolation effect of the gas surrounding the disk. The liquid subcooling is shown to drastically improuve the heat exchange thus reducing the cooling time (about 20 times). The effect of subcooling on the heat transfer is analyzed at different gravity levels. It is shown that such type of experiments cannot be used for the analysis of the critical heat flux (CHF) of the boiling crisis. The minimum heat flux (MHF) of boiling is analyzed instead.

  1. The effect of pre-cooling intensity on cooling efficiency and exercise performance

    NARCIS (Netherlands)

    Bogerd, N.; Perret, C.; Bogerd, C.P.; Rossi, R.M.; Daanen, H.A.M.

    2010-01-01

    Although pre-cooling is known to enhance exercise performance, the optimal cooling intensity is unknown. We hypothesized that mild cooling opposed to strong cooling circumvents skin vasoconstriction and thermogenesis, and thus improves cooling efficiency reflected in improved time to exhaustion. Eig

  2. Advanced lightweight cooling-garment technology: functional improvements in thermosensitive patients with multiple sclerosis.

    Science.gov (United States)

    Meyer-Heim, A; Rothmaier, M; Weder, M; Kool, J; Schenk, P; Kesselring, J

    2007-03-01

    Cooling of thermosensitive patients with multiple sclerosis (MS) can improve clinical symptoms. In order to study the effectiveness of an advanced lightweight cooling-garment technology based on aquatic evaporation, a single-blinded balanced crossover study was performed on 20 patients with an Expanded Disability Status Scale score garment prototype for peripheral cooling suggest improvement of a timed-walking test, leg-strength, fine-motor skills and subjective benefits. Preliminary data of the heart rate variability (HRV) including six patients suggest that the MS patients show an abnormal HRV after sham condition, which is normalized after cooling. Technical information was gained about the cooling activity and the practicability and handling of the device. These encouraging findings promote further adaptations of the prototype to increase its cooling properties and ameliorate the practicability of the cooling garment.

  3. Simulated Measurements of Cooling in Muon Ionization Cooling Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mohayai, Tanaz [IIT, Chicago; Rogers, Chris [Rutherford; Snopok, Pavel [Fermilab

    2016-06-01

    Cooled muon beams set the basis for the exploration of physics of flavour at a Neutrino Factory and for multi-TeV collisions at a Muon Collider. The international Muon Ionization Cooling Experiment (MICE) measures beam emittance before and after an ionization cooling cell and aims to demonstrate emittance reduction in muon beams. In the current MICE Step IV configuration, the MICE muon beam passes through low-Z absorber material for reducing its transverse emittance through ionization energy loss. Two scintillating fiber tracking detectors, housed in spectrometer solenoid modules upstream and downstream of the absorber are used for reconstructing position and momentum of individual muons for calculating transverse emittance reduction. However, due to existence of non-linear effects in beam optics, transverse emittance growth can be observed. Therefore, it is crucial to develop algorithms that are insensitive to this apparent emittance growth. We describe a different figure of merit for measuring muon cooling which is the direct measurement of the phase space density.

  4. National solar heating and cooling programs

    Energy Technology Data Exchange (ETDEWEB)

    Blum, S; Allen, J [eds.

    1979-08-01

    This document is a compilation of status reports on the national solar heating and cooling programs of seventeen countries participating in the Committee on the Challenges of Modern Society's Solar Energy Pilot Study. These reports were presented in two special sessions of the 25th Congress of the International Solar Energy Society held in May 1979, in Atlanta, Georgia, USA. This information exchange activity was part of the two-year follow up (1978-1980) of the Solar Energy Pilot Study, which ended in October 1978.

  5. Light Optics for Optical Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Andorf, Matthew [NICADD, DeKalb; Lebedev, Valeri [Fermilab; Piot, Philippe [NICADD, DeKalb; Ruan, Jinhao [Fermilab

    2016-06-01

    In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.

  6. Focus issue introduction: optical cooling and trapping.

    Science.gov (United States)

    Neves, Antonio A R; Jones, Philip H; Luo, Le; Maragò, Onofrio M

    2015-04-20

    The year 2015 is an auspicious year for optical science, as it is being celebrated as the International Year of Light and Light-Based Technologies. This Focus Issue of the journals Optics Express and Journal of the Optical Society of America B has been organized by the OSA Technical Group on Optical Cooling and Trapping to mark this occasion, and to highlight the most recent and exciting developments in the topics covered by the group. Together this joint Focus Issue features 32 papers, including both experimental and theoretical works, which span this wide range of activities.

  7. New Approaches to Final Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermilab

    2014-11-10

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

  8. Beam Dynamics With Electron Cooling

    CERN Document Server

    Uesugi, T; Noda, K; Shibuya, S; Syresin, E M

    2004-01-01

    Electron cooling experiments have been carried out at HIMAC in order to develop new technologies in heavy-ion therapy and related researches. The cool-stacking method, in particular, has been studied to increase the intensity of heavy-ions. The maximum stack intensity was 2 mA, above which a fast ion losses occurred simulatneously with the vertical coherent oscillations. The instability depends on the working point, the stacked ion-density and the electron-beam density. The instability was suppressed by reducing the peak ion-density with RF-knockout heating.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-01

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

  10. Slot film cooling: A comprehensive experimental characterization

    Science.gov (United States)

    Raffan, Fernando

    When components of a propulsion system are exposed to elevated flow temperatures there is a risk for catastrophic failure if the components are not properly protected from the thermal loads. Among several strategies, slot film cooling is one of the most commonly used, yet poorly understood active cooling techniques. Tangential injection of a relatively cool fluid layer protects the surface(s) in question, but the turbulent mixing between the hot mainstream and cooler film along with the presence of the wall presents an inherently complex problem where kinematics, thermal transport and multimodal heat transfer are coupled. Furthermore, new propulsion designs rely heavily on CFD analysis to verify their viability. These CFD models require validation of their results, and the current literature does not provide a comprehensive data set for film cooling that meets all the demands for proper validation, namely a comprehensive (kinematic, thermal and boundary condition data) data set obtained over a wide range of conditions. This body of work aims at solving the fundamental issue of validation by providing high quality comprehensive film cooling data (kinematics, thermal mixing, heat transfer). 3 distinct velocity ratios (VR=u c/uinfinity) are examined corresponding to wall-wake (VR˜0.5), min-shear (VR ˜ 1.0), and wall-jet (VR˜2.0) type flows at injection, while the temperature ratio TR= Tinfinity/Tc is approximately 1.5 for all cases. Turbulence intensities at injection are 2-4% for the mainstream (urms/uinfinity, vrms/uinfinity,), and on the order of 8-10% for the coolant (urms/uc, vrms/uc,). A special emphasis is placed on inlet characterization, since inlet data in the literature is often incomplete or is of relatively low quality for CFD development. The data reveals that min-shear injection provides the best performance, followed by the wall-jet. The wall-wake case is comparably poor in performance. The comprehensive data suggests that this relative performance

  11. A comparative study on showerhead cooling performance

    Energy Technology Data Exchange (ETDEWEB)

    Falcoz, C.; Ott, P. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratoire de Thermique Appliquee et de Turbomachines (LTT), 1015 Lausanne (Switzerland); Weigand, B. [Institut fuer Thermodynamik der Luft- und Raumfahrt (ITLR), Stuttgart University, Pfaffenwaldring 31, 70569 Stuttgart (Germany)

    2006-04-15

    In modern gas turbines, the turbine airfoil leading edge is currently protected from the hot gas by specific film cooling schemes, so called showerhead cooling. The present paper shows a numerical study of different showerhead cooling geometries. The 3D finite element program ABAQUS as well as a 2D finite element program have been employed to predict the showerhead cooling performance. In the numerical calculations, the different cooling effects and their contribution to the total showerhead cooling performance have been investigated separately. From the numerical calculations a simple method has been derived which enables the prediction of the performance of a 3D showerhead cooling scheme by simple 2D computations. Experimental investigations on showerhead cooling have been presented in a companion paper [C. Falcoz, B. Weigand, P. Ott, Experimental investigations on showerhead cooling on a blunt body. Int. J. Heat Mass Transfer, in press. r publication]. (author)

  12. Ecological impact of chloro-organics produced by chlorination of cooling tower waters

    Energy Technology Data Exchange (ETDEWEB)

    Jolley, R L; Cumming, R B; Pitt, W W; Taylor, F G; Thompson, J E; Hartmann, S J

    1977-01-01

    Experimental results of the initial assessment of chlorine-containing compounds in the blowdown from cooling towers and the possible mutagenic activity of these compounds are reported. High-resolution liquid chromatographic separations were made on concentrates of the blowdown from the cooling tower at the High Flux Isotope Reactor (HFIR) and from the recirculating water system for the cooling towers at the Oak Ridge Gaseous Diffusion Plant (ORGDP), Oak Ridge, Tennessee. The chromatograms of chlorinated cooling waters contained numerous uv-absorbing and cerate-oxidizable constituents that are now being processed through a multicomponent identification procedure. Concentrates of the chlorinated waters are also being examined for mutagenic activity.

  13. Solar heating and cooling of office and server rooms; Solares Kuehlen und Heizen von Buero- und Serverraeumen

    Energy Technology Data Exchange (ETDEWEB)

    Roessel, Timm; Krause, Michael; Lauterbach, Christoph [Fraunhofer-Inst. fuer Bauphysik, Abt. Energiesysteme, Kassel (Germany)

    2009-07-15

    At present, the air conditioning demand is worldwide increasing. Even if in summer overheating of office rooms can often be avoided through passive measures, server rooms usually require active cooling systems. Regarding this, solar cooling of office and server rooms is a promising concept for reducing the high energy consumption resulting from the cooling demand. (orig.)

  14. Real-Time Closed Loop Modulated Turbine Cooling

    Science.gov (United States)

    Shyam, Vikram; Culley, Dennis E.; Eldridge, Jeffrey; Jones, Scott; Woike, Mark; Cuy, Michael

    2014-01-01

    It has been noted by industry that in addition to dramatic variations of temperature over a given blade surface, blade-to-blade variations also exist despite identical design. These variations result from manufacturing variations, uneven wear and deposition over the life of the part as well as limitations in the uniformity of coolant distribution in the baseline cooling design. It is proposed to combine recent advances in optical sensing, actuation, and film cooling concepts to develop a workable active, closed-loop modulated turbine cooling system to improve by 10 to 20 the turbine thermal state over the flight mission, to improve engine life and to dramatically reduce turbine cooling air usage and aircraft fuel burn. A reduction in oxides of nitrogen (NOx) can also be achieved by using the excess coolant to improve mixing in the combustor especially for rotorcraft engines. Recent patents filed by industry and universities relate to modulating endwall cooling using valves. These schemes are complex, add weight and are limited to the endwalls. The novelty of the proposed approach is twofold 1) Fluidic diverters that have no moving parts are used to modulate cooling and can operate under a wide range of conditions and environments. 2) Real-time optical sensing to map the thermal state of the turbine has never been attempted in realistic engine conditions.

  15. Liquid cooling system for the vibro-tactile threshold device.

    Science.gov (United States)

    Parsons, Erin M; Redd, Christian; Gandhi, Minu S; Tuckett, Robert P; Bamberg, Stacy J Morris

    2011-01-01

    Vibrotactile threshold testing has been used to investigate activation of human somatosensory pathways. A portable vibrotactile threshold testing device called the Vibrotactile Threshold Evaluator for the Workplace (VTEW) was designed for screening of carpal tunnel syndrome in the workplace, and initially contained a small fan for cooling. During subject testing, the device is operated intermittently, which causes the linear actuator to warm the tactile probe. The probe causes discomfort for some subjects. During testing, the probe heated to 42 °C within 90 seconds of continuous operation. A liquid cooling system was implemented to dissipate heat from the probe. The liquid cooling system maintains a steady state temperature of 36 °C for continuous actuation of the probe. The liquid cooling system is capable of maintaining a safe operating temperature, without adding erroneous vibrations to the device. However, the cooling system deters the portability of the device. Further research will investigate how to make the liquid cooling system portable and implements vibrotactile threshold testing in the workplace to quickly evaluate whether or not a person has early symptoms of carpal tunnel syndrome.

  16. In-Vessel Storage Cooling Analysis in PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jung; Lee, Tae Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The IVS is the place where store the spent fuel temporarily. It is located in the annular space of the reactor core outside, and the spent fuel is stored for two cycles in IVS to reduce the decay heat and radioactivity. A total of 60 spent fuel can be stored in IVS, the minimum distance between spent fuels is more than 20 mm. The spent fuel is fixed in such a way that the nose piece is mounted on the receptacle, which is the same way as the core. Since the spent fuel stored in IVS generates the decay heat continuously, it is necessary to cool the spent fuel during the storage period. However, it is not possible to cool the spent fuel by using cold sodium in the inlet plenum because the orifice hole in the receptacle is blocked. In this study, the cooling performance of spent fuels in IVS by the natural convection due to the temperature difference between hot pool and IVS inside using CFD is assessed. The IVS cooling performance analysis using natural convection due to the temperature difference between the IVS and hot pool is evaluated by CFD. The analyses in various geometry and boundary condition are performed. For all cases, the temperature at the active bundle outlet is higher than 590 .deg. C. Therefore, the spent fuel cooling in IVS using natural convection is difficult to expect the cooling effect.

  17. Ionization Cooling for Muon Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Alexahin, Y. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Neuffer, D. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Prebys, E. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2014-09-18

    Possible application for muon experiments such as mu2e is discussed of the initial part of the ionization cooling channel originally developed for muon collider. It is shown that with the FNAL Booster as the proton driver the mu2e sensitivity can be increased by two orders of magnitude compared to the presently considered experiment.

  18. Ionization Cooling for Muon Experiments

    OpenAIRE

    Alexahin, Y.; D. Neuffer; Prebys, E.

    2014-01-01

    Possible application for muon experiments such as mu2e is discussed of the initial part of the ionization cooling channel originally developed for muon collider. It is shown that with the FNAL Booster as the proton driver the mu2e sensitivity can be increased by two orders of magnitude compared to the presently considered experiment.

  19. Inductive cooling in quantum magnetomechanics

    Science.gov (United States)

    Romero-Sanchez, Erick; Twamley, Jason; Bowen, Warwick P.; Vanner, Michael R.

    Coupling to light or microwave fields allows quantum control of the motion of a mechanical oscillator, and offers prospects for precision sensing, quantum information systems, and tests of fundamental physics. In cavity electromechanics ground state cooling has been achieved using resolved sideband cooling. Here we present an alternative approach based on a magnetomechanical system that inductively couples an LC resonator to a mechanical oscillator. The experimental setup consists of a micro cantilever with a pyramidal magnetic tip attached at the end of the beam. The sharp end of the magnetic tip is positioned close to the planar microfabricated inductor of the LC resonator. The displacement in the position of the end of the cantilever generates a change in flux through the coil inducing an electromotive force in the circuit. The current in the LC resonator generates a magnetic field, and then a force between the tip and the coil. When they are strongly coupled and the mechanical resonance frequency ωm exceeds the electrical decay rate of the resonator γe, resolved sideband cooling can be used to cool the mechanics. We present estimations for the coupling rates and the experimental parameters required for these experiments. E. Romero acknowledges to CONACyT.

  20. Cool Runnings For String 2

    CERN Multimedia

    2001-01-01

    String 2 is a series of superconducting magnets that are prototypes of those which will be installed in the LHC. It was cooled down to 1.9 Kelvin on September 14th. On Thursday last week, the dipoles of String 2 were successfully taken to nominal current, 11850 A.

  1. Garment Would Provide Variable Cooling

    Science.gov (United States)

    Buckley, Theresa M.

    1991-01-01

    Conceptual protective garment includes tubes containing pumped cooling slurry. Overall coefficient for transfer of heat from wearer to slurry depends on tube-to-skin, through-the-wall-of-the-tube, and tube-to-slurry coefficients. Concept applicable to suits worn when cleaning up spilled chemicals or fighting fires.

  2. Passive Cooling of Body Armor

    Science.gov (United States)

    Holtz, Ronald; Matic, Peter; Mott, David

    2013-03-01

    Warfighter performance can be adversely affected by heat load and weight of equipment. Current tactical vest designs are good insulators and lack ventilation, thus do not provide effective management of metabolic heat generated. NRL has undertaken a systematic study of tactical vest thermal management, leading to physics-based strategies that provide improved cooling without undesirable consequences such as added weight, added electrical power requirements, or compromised protection. The approach is based on evaporative cooling of sweat produced by the wearer of the vest, in an air flow provided by ambient wind or ambulatory motion of the wearer. Using an approach including thermodynamic analysis, computational fluid dynamics modeling, air flow measurements of model ventilated vest architectures, and studies of the influence of fabric aerodynamic drag characteristics, materials and geometry were identified that optimize passive cooling of tactical vests. Specific architectural features of the vest design allow for optimal ventilation patterns, and selection of fabrics for vest construction optimize evaporation rates while reducing air flow resistance. Cooling rates consistent with the theoretical and modeling predictions were verified experimentally for 3D mockups.

  3. Solar-powered cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C

    2013-12-24

    A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

  4. A cool present for LEIR

    CERN Multimedia

    2005-01-01

    LEIR (Low Energy Ion Ring), which will supply lead ions to the LHC experiments, has taken delivery of one of its key components, its electron cooling system. From left to right, Gérard Tranquille, Virginia Prieto and Roland Sautier, in charge of the electron cooling system for LEIR at CERN, and Christian Lacroix, in charge of installation for the LEIR machine. On 16 December, the day before CERN's annual closure, the LEIR teams received a rather impressive Christmas present. The "parcel" from Russia, measuring 7 metres in length and 4 metres in height, weighed no less than 20 tonnes! The component will, in fact, be one of the key elements of the future LEIR, namely its electron cooling system. LEIR is one of the links in the injector chain that will supply lead ions to the LHC experiments, in particular ALICE (see Bulletin No. 28/2004 of 5 July 2004), within the framework of the I-LHC Project. The electron cooling system is designed to reduce and standardise transverse ion velocity. This focuses the bea...

  5. RAMI analysis for DEMO HCPB blanket concept cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Dongiovanni, Danilo N., E-mail: danilo.dongiovanni@enea.it [ENEA, Unità Tecnica Fusione, ENEA C. R. Frascati (Italy); Pinna, Tonio [ENEA, Unità Tecnica Fusione, ENEA C. R. Frascati (Italy); Carloni, Dario [KIT, Institute of Neutron Physics and Reactor Technology (INR) – KIT (Germany)

    2015-10-15

    Highlights: • RAMI (reliability, availability, maintainability and inspectability) preliminary assessment for HCPB blanket concept cooling system. • Reliability block diagram (RBD) modeling and analysis for HCPB primary heat transfer system (PHTS), coolant purification system (CPS), pressure control system (PCS), and secondary cooling system. • Sensitivity analysis on system availability performance. • Failure models and repair models estimated on the base of data from the ENEA fusion component failure rate database (FCFRDB). - Abstract: A preliminary RAMI (reliability, availability, maintainability and inspectability) assessment for the HCPB (helium cooled pebble bed) blanket cooling system based on currently available design for DEMO fusion power plant is presented. The following sub-systems were considered in the analysis: blanket modules, primary cooling loop including pipework and steam generators lines, pressure control system (PCS), coolant purification system (CPS) and secondary cooling system. For PCS and CPS systems an extrapolation from ITER Test Blanket Module corresponding systems was used as reference design in the analysis. Helium cooled pebble bed (HCPB) system reliability block diagrams (RBD) models were implemented taking into account: system reliability-wise configuration, operating schedule currently foreseen for DEMO, maintenance schedule and plant evolution schedule as well as failure and corrective maintenance models. A simulation of plant activity was then performed on implemented RBDs to estimate plant availability performance on a mission time of 30 calendar years. The resulting availability performance was finally compared to availability goals previously proposed for DEMO plant by a panel of experts. The study suggests that inherent availability goals proposed for DEMO PHTS system and Tokamak auxiliaries are potentially achievable for the primary loop of the HCPB concept cooling system, but not for the secondary loop. A

  6. Multiple views of magnetism in cool stars

    CERN Document Server

    Morin, J; Reiners, A; Shulyak, D; Beeck, B; Hallinan, G; Hebb, L; Hussain, G; Jeffers, S V; Kochukhov, O; Vidotto, A; Walkowicz, L

    2012-01-01

    Magnetic fields are regarded as a crucial element for our understanding of stellar physics. They can be studied with a variety of methods which provide complementary - and sometimes contradictory - information about the structure, strength and dynamics of the magnetic field and its role in the evolution of stars. Stellar magnetic fields can be investigated either with direct methods based on the Zeeman effect or through the observation of activity phenomena resulting from the interaction of the field with the stellar atmosphere. In this Cool Stars XVII Splinter Session we discussed the results obtained by the many ongoing studies of stellar activity and direct studies of surface magnetic fields, as well as the state- of-the-art techniques on which they are based. We show the strengths and limitations of the various approaches currently used and to point out their evolution as well as the interest of coupling various magnetism and activity proxies.

  7. An Experimental Investigation on Transpiration Cooling Part II: Comparison of Cooling Methods and Media

    OpenAIRE

    Wang J; Messner J.; Stetter H.

    2004-01-01

    This article attempts to provide a cooling performance comparison of various mass transfer cooling methods and different cooling media through two experiments. In the first experiment, pressurized air was used as a cooling medium and two different circular tubes were used as specimens. One is made of impermeable solid material with four rows of discrete holes to simulate film cooling, and the other consists of sintered porous material to create a porous transpiration cooling effect. The...

  8. Gas turbine heat transfer and cooling technology

    CERN Document Server

    Han, Je-Chin; Ekkad, Srinath

    2012-01-01

    FundamentalsNeed for Turbine Blade CoolingTurbine-Cooling TechnologyTurbine Heat Transfer and Cooling IssuesStructure of the BookReview Articles and Book Chapters on Turbine Cooling and Heat TransferNew Information from 2000 to 2010ReferencesTurbine Heat TransferIntroductionTurbine-Stage Heat TransferCascade Vane Heat-Transfer ExperimentsCascade Blade Heat TransferAirfoil Endwall Heat TransferTurbine Rotor Blade Tip Heat TransferLeading-Edge Region Heat TransferFlat-Surface Heat TransferNew Information from 2000 to 20102.10 ClosureReferencesTurbine Film CoolingIntroductionFilm Cooling on Rotat

  9. Multi-pass cooling for turbine airfoils

    Science.gov (United States)

    Liang, George

    2011-06-28

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

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

    Science.gov (United States)

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

    2006-01-01

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

  11. Air cooling : an experimental method of evaluating the cooling effect of air streams on air-cooled cylinders

    Science.gov (United States)

    Alcock, J F

    1927-01-01

    In this report is described an experimental method which the writer has evolved for dealing with air-cooled engines, and some of the data obtained by its means. Methods of temperature measurement and cooling are provided.

  12. Cooling does not affect knee proprioception.

    Science.gov (United States)

    Ozmun, J C; Thieme, H A; Ingersoll, C D; Knight, K L

    1996-01-01

    The effect of cooling on proprioception of the knee has not been studied extensively. In this study, we investigated the movement reproduction (timing and accuracy) aspect of proprioception. Subjects were tested under two conditions: a 20-minute application of ice and control. Proprioceptive accuracy and timing were measured by passively moving the knee, then comparing the subject's active reproduction of the passive movement. Subjects were blindfolded, then tested in three sectors of the knee's range of motion: 90 degrees to 60 degrees , 60 degrees to 30 degrees , and 30 degrees to full extension. Ice application had no apparent effect on the subject's ability to perform accurate movement reproductions in the sectors tested. However, accuracy of the subject's final angle reproduction varied between the sectors as did the total time of the movement. One possible explanation for the difference between sectors is that different receptors are active at different points in the knee's range of motion. We conclude that cooling the knee joint for 20 minutes does not have an adverse effect on proprioception.

  13. Cool Cluster Correctly Correlated

    Energy Technology Data Exchange (ETDEWEB)

    Varganov, Sergey Aleksandrovich [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    Atomic clusters are unique objects, which occupy an intermediate position between atoms and condensed matter systems. For a long time it was thought that physical and chemical properties of atomic dusters monotonically change with increasing size of the cluster from a single atom to a condensed matter system. However, recently it has become clear that many properties of atomic clusters can change drastically with the size of the clusters. Because physical and chemical properties of clusters can be adjusted simply by changing the cluster's size, different applications of atomic clusters were proposed. One example is the catalytic activity of clusters of specific sizes in different chemical reactions. Another example is a potential application of atomic clusters in microelectronics, where their band gaps can be adjusted by simply changing cluster sizes. In recent years significant advances in experimental techniques allow one to synthesize and study atomic clusters of specified sizes. However, the interpretation of the results is often difficult. The theoretical methods are frequently used to help in interpretation of complex experimental data. Most of the theoretical approaches have been based on empirical or semiempirical methods. These methods allow one to study large and small dusters using the same approximations. However, since empirical and semiempirical methods rely on simple models with many parameters, it is often difficult to estimate the quantitative and even qualitative accuracy of the results. On the other hand, because of significant advances in quantum chemical methods and computer capabilities, it is now possible to do high quality ab-initio calculations not only on systems of few atoms but on clusters of practical interest as well. In addition to accurate results for specific clusters, such methods can be used for benchmarking of different empirical and semiempirical approaches. The atomic clusters studied in this work contain from a few atoms

  14. A combined capillary cooling system for cooling fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ana Paula; Pelizza, Pablo Rodrigo; Galante, Renan Manozzo; Bazzo, Edson [Universidade Federal de Santa Catarina (LabCET/UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], Emails: ana@labcet.ufsc.br, pablo@labcet.ufsc.br, renan@labcet.ufsc.br, ebazzo@emc.ufsc.br

    2010-07-01

    The operation temperature control has an important influence over the PEMFC (Proton Exchange Membrane Fuel Cell) performance. A two-phase heat transfer system is proposed as an alternative for cooling and thermal control of PEMFC. The proposed system consists of a CPL (Capillary Pumped Loop) connected to a set of constant conductance heat pipes. In this work ceramic wick and stainless mesh wicks have been used as capillary structure of the CPL and heat pipes, respectively. Acetone has been used as the working fluid for CPL and deionized water for the heat pipes. Experimental results of three 1/4 inch stainless steel outlet diameter heats pipes and one CPL have been carried out and presented in this paper. Further experiments are planned coupling the proposed cooling system to a module which simulates the fuel cell. (author)

  15. Solar-driven high temperature radiant cooling

    Institute of Scientific and Technical Information of China (English)

    SONG ZhaoPei; WANG RuZhu; ZHAI XiaoQiang

    2009-01-01

    Solar energy is widely used as one of the most important renewable energy. In addition to the growing applications of solar PV and solar water heater, solar cooling is also considered very valuable and the related researches are developing fast because of the synchronism between solar irradiance and building cooling load. Current studies mainly focus on the high temperature solar collector technique and heat-driven cooling technique, while little concern has been paid to the transport process of cooling power. In this paper, the high temperature radiant cooling is studied as an alternative way for transporting cooling power, and the performance of the combination of radiant ceiling and solar cooling is also studied. From simulation and theoretical analysis results, high temperature radiant cooling terminal shows better cooling power transportation ability against conventional air-conditioning terminal, and its thermal comfort is improved. Experiment results indicate that radiant cooling can enhance the chiller's COP (Coefficient of Performance) by 17% and cooling power regeneration by 50%.According to analysis in this paper, high temperature radiant cooling is proved to be suitable for solar cooling system, and out work can serve as a reference for later system design and promotion.

  16. Sympathetic cooling of molecules with laser-cooled atoms

    Science.gov (United States)

    Hudson, Eric

    2014-05-01

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

  17. Cooling power of transverse thermoelectrics for cryogenic cooling

    Science.gov (United States)

    Tang, Yang; Ma, Ming; Grayson, M.

    2016-05-01

    Transverse Peltier coolers have been experimentally and theoretically studied since 1960s due to their capability of achieving cooling in a single-leg geometry. Recently proposed pxn-type transverse thermoelectrics reveal the possibility of intrinsic or undoped transverse coolers that can, in principle, function at cryogenic temperatures, which has drawn more attention to the performance of such transverse coolers. However, unlike longitudinal thermoelectrics, the equations for transverse thermoelectrics cannot be solved analytically. In this study, we therefore calculate the thermoelectric transport in transverse coolers numerically, and introduce a normalized notation, which reduces the independent parameters in the governing equations to a normalized electric field E* and a hot-side transverse figure of merit zTh, only. A numerical study of the maximum cooling temperature difference and cooling power reveals the superior performance of transverse thermoelectric coolers compared to longitudinal coolers with the same figure of merit, providing another motivation in the search for new transverse thermoelectric materials with large figure of merit.

  18. Design: More than a cool chair

    DEFF Research Database (Denmark)

    Friis, Silje Alberthe Kamille; Austin, Robert; Sullivan, Erin

    2006-01-01

    Austin, R., Friis, K., Sullivan, E. 2006. Design: More than a cool chair. Boston: Harvard Business School Publishing.......Austin, R., Friis, K., Sullivan, E. 2006. Design: More than a cool chair. Boston: Harvard Business School Publishing....

  19. Lattice Regenerative Cooling Methods (LRCM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop and demonstrate a novel cooling concept called Lattice Regenerative Cooling Methods (LRCM) for future high thrust in-space propulsion...

  20. High temperature cooling system and method

    Science.gov (United States)

    Loewen, Eric P.

    2006-12-12

    A method for cooling a heat source, a method for preventing chemical interaction between a vessel and a cooling composition therein, and a cooling system. The method for cooling employs a containment vessel with an oxidizable interior wall. The interior wall is oxidized to form an oxide barrier layer thereon, the cooling composition is monitored for excess oxidizing agent, and a reducing agent is provided to eliminate excess oxidation. The method for preventing chemical interaction between a vessel and a cooling composition involves introducing a sufficient quantity of a reactant which is reactive with the vessel in order to produce a barrier layer therein that is non-reactive with the cooling composition. The cooling system includes a containment vessel with oxidizing agent and reducing agent delivery conveyances and a monitor of oxidation and reduction states so that proper maintenance of a vessel wall oxidation layer occurs.

  1. Turbine airfoil with ambient cooling system

    Science.gov (United States)

    Campbell, Jr, Christian X.; Marra, John J.; Marsh, Jan H.

    2016-06-07

    A turbine airfoil usable in a turbine engine and having at least one ambient air cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels configured to receive ambient air at about atmospheric pressure. The ambient air cooling system may have a tip static pressure to ambient pressure ratio of at least 0.5, and in at least one embodiment, may include a tip static pressure to ambient pressure ratio of between about 0.5 and about 3.0. The cooling system may also be configured such that an under root slot chamber in the root is large to minimize supply air velocity. One or more cooling channels of the ambient air cooling system may terminate at an outlet at the tip such that the outlet is aligned with inner surfaces forming the at least one cooling channel in the airfoil to facilitate high mass flow.

  2. Theoretical analysis of the performance of different cooling strategies with the concept of cool exergy

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    The whole chains of exergy flows for different cooling systems were compared. The effects of cooling demand (internal vs. external solar shading), space cooling method (floor cooling vs. air cooling with ventilation system), and the availability of a nearby natural heat sink (intake air for the v......The whole chains of exergy flows for different cooling systems were compared. The effects of cooling demand (internal vs. external solar shading), space cooling method (floor cooling vs. air cooling with ventilation system), and the availability of a nearby natural heat sink (intake air......-water, etc.) and indoor terminal units, only with a minimized demand. The water-based floor cooling system performed better than the air-based cooling system; when an air-to-water heat pump was used as the cooling source, the required exergy input was 28% smaller for the floor cooling system. The auxiliary...... exergy input of air-based systems was significantly larger than the water-based systems. The use of available cool exergy in the crawl-space resulted in 54% and 29% smaller exergy input to the power plant for the air-based and water-based cooling systems, respectively. For floor cooling, the exergy input...

  3. Information technology equipment cooling method

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Mark D.

    2015-10-20

    According to one embodiment, a system for removing heat from a rack of information technology equipment may include a sidecar indoor air to liquid heat exchanger that cools air utilized by the rack of information technology equipment to cool the rack of information technology equipment. The system may also include a liquid to liquid heat exchanger and an outdoor heat exchanger. The system may further include configurable pathways to connect and control fluid flow through the sidecar heat exchanger, the liquid to liquid heat exchanger, the rack of information technology equipment, and the outdoor heat exchanger based upon ambient temperature and/or ambient humidity to remove heat generated by the rack of information technology equipment.

  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. Integrated circuit cooled turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ching-Pang; Jiang, Nan; Um, Jae Y.; Holloman, Harry; Koester, Steven

    2017-08-29

    A turbine rotor blade includes at least two integrated cooling circuits that are formed within the blade that include a leading edge circuit having a first cavity and a second cavity and a trailing edge circuit that includes at least a third cavity located aft of the second cavity. The trailing edge circuit flows aft with at least two substantially 180-degree turns at the tip end and the root end of the blade providing at least a penultimate cavity and a last cavity. The last cavity is located along a trailing edge of the blade. A tip axial cooling channel connects to the first cavity of the leading edge circuit and the penultimate cavity of the trailing edge circuit. At least one crossover hole connects the penultimate cavity to the last cavity substantially near the tip end of the blade.

  6. Cooling Augmentation with Microchanneled Structures

    Institute of Scientific and Technical Information of China (English)

    X.F.Peng; B.X.Wang

    1993-01-01

    Experiments were conducted to investigate the heat transfer characteristics and cooling performance of subcooled liquid,water,flowing through rectangular cross-section microchanneled structures machined on a stainless steel plate.Heat transfer or flow mode stransition was observed when the heating rate or wall temperature was increased.This transition was found to be suggestively induced by the variation in liquid thermophysical properties due to the significant rise of liquid temperature in the microstructures.The influence of such parameters as liquid velocity,subcooling,property variation,and microchannel geometric configuration on the heat transfer behavior,cooling performance and the heat transfer and liquid flow mode transition were also investigated.The experiments indicated that both single-phase forced convection and flow boiling characteristics were quite different from those in normal-sized tubes and the heat transfer was obviously intensified.

  7. Renewables for Heating and Cooling

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This timely report examines the technologies, current markets and relative costs for heat and cold production using biomass, geothermal and solar-assisted systems. It evaluates a range of national case studies and relevant policies. Should the successful and more cost-effective policies be implemented by other countries, then the relatively untapped economic potential of renewable energy heating and cooling systems could be better realised, resulting in potential doubling of the present market within the next few years.

  8. Lightweight Passive Microclimate Cooling Device

    Science.gov (United States)

    1993-03-01

    vapor-compression air conditioning system, thereby providing the cooling. Such a design is superior to Stirling or Brayton approaches in terms of...adsorption system, since all of the materials used in these experiments were from either oven-dried or vacuum-system- regenerated desiccant. Full-Scale Backpack...current design has an overall volume of 7.04 L, which is adequate. Part of this volume is not available due to the regeneration tubes and the needed free

  9. Cooling system for electronic components

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

    2016-05-17

    Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

  10. Cooling system for electronic components

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

    2015-12-15

    Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

  11. Ozone Treatment For Cooling Towers

    Science.gov (United States)

    Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

    1990-01-01

    Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

  12. THE INITIAL COOLING EXPERIMENT (ICE)

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    ICE was built during 1977, in a record time of 9 months, using the modified bending magnets of the g-2 muon storage ring (see 7405430). ICE was a proton and antiproton storage ring, built to verify the validity of stochastic and electron cooling for the antiproton project to be launched in 1978. More on the ICE experimental programme with 7802099. See also 7809081, 7908242.

  13. Gas cooled traction drive inverter

    Science.gov (United States)

    Chinthavali, Madhu Sudhan

    2013-10-08

    The present invention provides a modular circuit card configuration for distributing heat among a plurality of circuit cards. Each circuit card includes a housing adapted to dissipate heat in response to gas flow over the housing. In one aspect, a gas-cooled inverter includes a plurality of inverter circuit cards, and a plurality of circuit card housings, each of which encloses one of the plurality of inverter cards.

  14. Gas cooled traction drive inverter

    Energy Technology Data Exchange (ETDEWEB)

    Chinthavali, Madhu Sudhan

    2016-04-19

    The present invention provides a modular circuit card configuration for distributing heat among a plurality of circuit cards. Each circuit card includes a housing adapted to dissipate heat in response to gas flow over the housing. In one aspect, a gas-cooled inverter includes a plurality of inverter circuit cards, and a plurality of circuit card housings, each of which encloses one of the plurality of inverter cards.

  15. Cooling of suspended nanostructures with tunnel junctions

    OpenAIRE

    Koppinen, P. J.; Maasilta, I. J.

    2009-01-01

    We have investigated electronic cooling of suspended nanowires with SINIS tunnel junction coolers. The suspended samples consist of a free standing nanowire suspended by four narrow ($\\sim$ 200 nm) bridges. We have compared two different cooler designs for cooling the suspended nanowire. We demonstrate that cooling of the nanowire is possible with a proper SINIS cooler design.

  16. Quantum trajectory pictures of laser cooling

    NARCIS (Netherlands)

    Nienhuis, G.; Kloe, J. de; Straten, P. van der

    1997-01-01

    We have applied the method of single atom trajectories to study the mechanism behind some cooling schemes in laser cooling. In several cases we recognize the cooling mechanism as being due to a "Sisyphus" process, where the atoms move in a spatially varying light shift potential and are optically pu

  17. Desalting a process cooling water using nanofiltration

    NARCIS (Netherlands)

    Radier, R.G.J.; van Oers, C.W.; Steenbergen, A.; Wessling, Matthias

    2001-01-01

    The cooling water system of a chemical plant of Akzo Nobel is a partly open system. The site is located at the North Sea. The air in contact with the cooling water contains seawater droplets dissolving and increasing the chloride concentration. The cooling water contains chromate to protect the inst

  18. 46 CFR 182.420 - Engine cooling.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Engine cooling. 182.420 Section 182.420 Shipping COAST...) MACHINERY INSTALLATION Specific Machinery Requirements § 182.420 Engine cooling. (a) Except as otherwise provided in paragraphs (b), (c), (d), and (e) of this section, all engines must be water cooled and...

  19. 46 CFR 119.420 - Engine cooling.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Engine cooling. 119.420 Section 119.420 Shipping COAST... Machinery Requirements § 119.420 Engine cooling. (a) Except as otherwise provided in paragraph (b) of this section, all engines must be water cooled and meet the requirements of this paragraph. (1) The engine...

  20. 40 CFR 89.327 - Charge cooling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Charge cooling. 89.327 Section 89.327....327 Charge cooling. For engines with an air-to-air intercooler (or any other low temperature charge air cooling device) between the turbocharger compressor and the intake manifold, follow SAE...

  1. 24 CFR 3280.714 - Appliances, cooling.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Appliances, cooling. 3280.714... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Heating, Cooling and Fuel Burning Systems § 3280.714 Appliances, cooling. (a) Every air conditioning unit or a combination air...

  2. Quantum trajectory pictures of laser cooling

    NARCIS (Netherlands)

    Nienhuis, G.; Kloe, J. de; Straten, P. van der

    1997-01-01

    We have applied the method of single atom trajectories to study the mechanism behind some cooling schemes in laser cooling. In several cases we recognize the cooling mechanism as being due to a "Sisyphus" process, where the atoms move in a spatially varying light shift potential and are optically

  3. Optomechanical laser cooling with mechanical modulations

    OpenAIRE

    Bienert, Marc; Barberis-Blostein, Pablo

    2014-01-01

    We theoretically study the laser cooling of cavity optomechanics when the mechanical resonance frequency and damping depend on time. In the regime of weak optomechanical coupling we extend the theory of laser cooling using an adiabatic approximation. We discuss the modifications of the cooling dynamics and compare it with numerical simulations in a wide range of modulation frequencies.

  4. Disk Instabilities and Cooling Fronts

    CERN Document Server

    Vishniac, E T

    1998-01-01

    Accretion disk outbursts, and their subsequent decline, offer a unique opportunity to constrain the physics of angular momentum transport in hot accretion disks. Recent work has centered on the claim by Cannizzo et al. that the exponential decay of luminosity following an outburst in black hole accretion disk systems is only consistent with a particular form for the dimensionless viscosity, $\\alpha=35(c_s/r\\Omega)^{3/2}$. This result can be understood in terms of a simple model of the evolution of cooling fronts in accretion disks. In particular, the cooling front speed during decline is $\\sim cooling front, and the exact value of $n$ depends on the hot state opacity, (although generally $n\\approx 1/2$). Setting this speed proportional to $r$ constrains the functional form of $\\alpha$ in the hot phase of the disk, which sets it apart from previous arguments based on the relative durations of outburst and quiescence. However, it remains uncertain how well we know the exponent $n$. In addition, more work is nee...

  5. Coolness both underlies and protects against the painfulness of the thermal grill illusion.

    Science.gov (United States)

    Harper, Daniel E; Hollins, Mark

    2014-04-01

    We investigated the contributions of warm and cool signals in generating the thermal grill illusion (TGI), a phenomenon in which interlaced warm and cool bars generate an experience of burning, and under some conditions painful, heat. Each subject underwent 3 runs, 2 of which tested the effects of preadapting subjects to the grill's warm or cool bars (while the interlaced bars were thermally neutral) on the subsequent intensity of the illusion. In a control run, all bars were neutral during the adaptation phase. Thermal visual analogue scale ratings during the warm and cool adaptation periods revealed significant and equivalent adaptation to the 2 temperatures. Adaptation to the grill's cool bars significantly reduced pain and perceived thermal intensity of the TGI, compared to the control condition, while adaptation to the grill's warm bars had little effect. These results suggest that the cool stimulus triggers the pain signals that produce the illusion. The inability of warm adaptation to attenuate the TGI is at odds with theories suggesting that the illusion depends upon a simple addition of warm and cool signals. While the grill's cool bars are necessary for the TGI's painfulness, we also observed that the more often a participant reported feeling coolness or coldness, the less pain he or she experienced from the TGI. These results are consistent with research showing that cool temperatures generate activity in both thermoreceptive-specific, pain-inhibitory neurons and nociceptive dorsal horn neurons.

  6. High conductivity Be-Cu alloys for fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lilley, E.A. [NGK Metals Corp., Reading, PA (United States); Adachi, Takao; Ishibashi, Yoshiki [NGK Insulators, Ltd., Aichi-ken (Japan)

    1995-09-01

    The optimum material has not yet been identified. This will result in heat from plasma to the first wall and divertor. That is, because of cracks and melting by thermal power and shock. Today, it is considered to be some kinds of copper, alloys, however, for using, it must have high conductivity. And it is also needed another property, for example, high strength and so on. We have developed some new beryllium copper alloys with high conductivity, high strength, and high endurance. Therefore, we are introducing these new alloys as suitable materials for the heat sink in fusion reactors.

  7. Cooling-induced contraction in ovine airways smooth muscle.

    Science.gov (United States)

    Mustafa, S M; Pilcher, C W; Williams, K I

    1999-02-01

    The mechanism of cold-induced bronchoconstriction is poorly understood. This prompted the present study whose aim was to determine the step-wise direct effect of cooling on smooth muscle of isolated ovine airways and analyse the role of calcium in the mechanisms involved. Isolated tracheal strips and bronchial segments were suspended in organ baths containing Krebs' solution for isometric tension recording. Tissue responses during stepwise cooling from 37 to 5 degrees C were examined. Cooling induced a rapid and reproducible contraction proportional to cooling temperature in ovine tracheal and bronchial preparations which was epithelium-independent. On readjustment to 37 degrees C the tone returned rapidly to basal level. Maximum contraction was achieved at a temperature of 5 degrees C for trachea and 15 degrees C for bronchiole. Cooling-induced contractions (CIC) was resistant to tetrodotoxin (1; 10 micrometer), and not affected by the muscarinic antagonist atropine (1 micrometer) or the alpha-adrenergic antagonist phentolamine (1 micrometer), or the histamine H1-antagonist mepyramine (1 micrometer) or indomethacin (1 micrometer). Ca2+ antagonists (nifedipine and verapamil) and Mn2+ raised tracheal but not bronchiolar tone and augmented CIC. Incubation in Ca2+-free, EGTA-containing Krebs' solution for 5 min had no effect on CIC, although it significantly reduced KCl-induced contraction by up to 75%. Cooling inhibited Ca2+ influx measured using 45Ca2+ uptake. Caffeine (100 micrometer) significantly inhibited CIC. The results show that cooling-induced contractions do not appear to involve activation of nerve endings, all surface reception systems or Ca2+ influx. However, CIC is mainly dependent on release of intracellular Ca2+.

  8. Convective cores in galactic cooling flows

    CERN Document Server

    Kritsuk, A G; Müller, E

    2000-01-01

    We use hydrodynamic simulations with adaptive grid refinement to study the dependence of hot gas flows in X-ray luminous giant elliptical galaxies on the efficiency of heat supply to the gas. We consider a number of potential heating mechanisms including Type Ia supernovae and sporadic nuclear activity of a central supermassive black hole. As a starting point for this research we use an equilibrium hydrostatic recycling model (Kritsuk 1996). We show that a compact cooling inflow develops, if the heating is slightly insufficient to counterbalance radiative cooling of the hot gas in the central few kiloparsecs. An excessive heating in the centre, instead, drives a convectively unstable outflow. We model the onset of the instability and a quasi-steady convective regime in the core of the galaxy in two-dimensions assuming axial symmetry. Provided the power of net energy supply in the core is not too high, the convection remains subsonic. The convective pattern is dominated by buoyancy driven large-scale mushroom-...

  9. Propagation Limits of High Pressure Cool Flames

    Science.gov (United States)

    Ju, Yiguang

    2016-11-01

    The flame speeds and propagation limits of premixed cool flames at elevated pressures with radiative heat loss are numerically modelled using dimethyl ether mixtures. The primary focus is paid on the effects of pressure, mixture dilution, flame size, and heat loss on cool flame propagation. The results showed that cool flames exist on both fuel lean and fuel rich sides and thus dramatically extend the lean and rich flammability limits. There exist three different flame regimes, hot flame, cool flame, and double flame. A new flame flammability diagram including both cool flames and hot flames is obtained at elevated pressure. The results show that pressure significantly changes cool flame propagation. It is found that the increases of pressure affects the propagation speeds of lean and rich cool flames differently due to the negative temperature coefficient effect. On the lean side, the increase of pressure accelerates the cool flame chemistry and shifts the transition limit of cool flame to hot flame to lower equivalence ratio. At lower pressure, there is an extinction transition from hot flame to cool flame. However, there exists a critical pressure above which the cool flame to hot flame transition limit merges with the lean flammability limit of the hot flame, resulting in a direct transition from hot flame to cool flame. On the other hand, the increase of dilution reduces the heat release of hot flame and promotes cool flame formation. Moreover, it is shown that a smaller flame size and a higher heat loss also extend the cool flame transition limit and promote cool flame formation.

  10. Effects of Deep Cooling and Re-Warming on Ionotropic Glutamatergic Receptors In Vitro.

    Science.gov (United States)

    Mokrushin, A A

    2016-05-01

    We studied the effects of cooling to -10°C and re-warming to 37°C on slices of rat olfactory cortex. The amplitudes of action potential in the lateral olfactory tract and excitatory postsynaptic potential activated by AMPA recovered during slow cooling/re-warming (0.1°C/min), while during rapid cooling/re-warming (9°C/min), they surpassed the control values. NMDA receptor-dependent mechanism was blocked in both cooling/re-warming modes. Swelling of the brain slices was observed during re-warming, especially during rapid cooling/re-warming. Nerve fibers of the lateral olfactory tract and AMPA-related processes survived deep cooling/re-warming, while NMDA-related processes were irreversibly blocked.

  11. Experimental evaluation of cooling efficiency of the high performance cooling device

    Science.gov (United States)

    Nemec, Patrik; Malcho, Milan

    2016-06-01

    This work deal with experimental evaluation of cooling efficiency of cooling device capable transfer high heat fluxes from electric elements to the surrounding. The work contain description of cooling device, working principle of cooling device, construction of cooling device. Experimental part describe the measuring method of device cooling efficiency evaluation. The work results are presented in graphic visualization of temperature dependence of the contact area surface between cooling device evaporator and electronic components on the loaded heat of electronic components in range from 250 to 740 W and temperature dependence of the loop thermosiphon condenser surface on the loaded heat of electronic components in range from 250 to 740 W.

  12. Trends in HPC and Data Center Power, Packaging, and Cooling

    CERN Document Server

    CERN. Geneva

    2016-01-01

    air vs liquid-cooling, and metrics to track it all will be discussed. About the speaker Michael K. Patterson is a Senior Principal Engineer in the Technical Computing Group - Systems Architecture & Pathfinding at the Intel Corporation, in Dupont, Washington, where he works in the power, thermal, and energy-efficient-performance areas of High Performance Computing. The work covers silicon level activity, through platform and rack-level solutions, and on up to interface with Data Center power and cooling technologies. He did his undergraduate work at Purdue University, received his MS degree in Management from Rensselaer Polytechnic Institute, an...

  13. Enhanced Optomechanical Cooling at High-Order Exceptional Points

    CERN Document Server

    Jing, H; Lü, H; Nori, Franco

    2016-01-01

    We study mechanical cooling in systems of coupled passive (lossy) and active (with gain) optical resonators. We find that for a driving laser which is red-detuned with respect to the cavity frequency, the supermode structure of the system is radically changed, featuring the emergence of genuine high-order exceptional points. This in turn leads to giant enhancement of both the mechanical damping and the spring stiffness, facilitating low-power mechanical cooling in the vicinity of gain-loss balance. This opens up new avenues of steering micromechanical devices with exceptional points beyond the lowest-order two.

  14. Maisotsenko cycle applications for multistage compressors cooling

    Science.gov (United States)

    Levchenko, D.; Yurko, I.; Artyukhov, A.; Baga, V.

    2017-08-01

    The present study provides the overview of Maisotsenko Cycle (M-Cycle) applications for gas cooling in compressor systems. Various schemes of gas cooling systems are considered regarding to their thermal efficiency and cooling capacity. Preliminary calculation of M-cycle HMX has been conducted. It is found that M-cycle HMX scheme allows to brake the limit of the ambient wet bulb temperature for evaporative cooling. It has demonstrated that a compact integrated heat and moisture exchange process can cool product fluid to the level below the ambient wet bulb temperature, even to the level of dew point temperature of the incoming air with substantially lower water and energy consumption requirements.

  15. Cooling arrangement for a gas turbine component

    Science.gov (United States)

    Lee, Ching-Pang; Heneveld, Benjamin E

    2015-02-10

    A cooling arrangement (82) for a gas turbine engine component, the cooling arrangement (82) having a plurality of rows (92, 94, 96) of airfoils (98), wherein adjacent airfoils (98) within a row (92, 94, 96) define segments (110, 130, 140) of cooling channels (90), and wherein outlets (114, 134) of the segments (110, 130) in one row (92, 94) align aerodynamically with inlets (132, 142) of segments (130, 140) in an adjacent row (94, 96) to define continuous cooling channels (90) with non continuous walls (116, 120), each cooling channel (90) comprising a serpentine shape.

  16. 3D Sisyphus Cooling of Trapped Ions

    CERN Document Server

    Ejtemaee, S

    2016-01-01

    Using a laser polarization gradient, we realize 3D Sisyphus cooling of $^{171}$Yb$^+$ ions confined in and near the Lamb-Dicke regime in a linear Paul trap. The cooling rate and final mean motional energy of a single ion are characterized as a function of laser intensity and compared to semiclassical and quantum simulations. Sisyphus cooling is also applied to a linear string of four ions to obtain a mean energy of 1-3 quanta for all vibrational modes, an approximately order-of-magnitude reduction below Doppler cooled energies. This is used to enable subsequent, efficient sideband laser cooling.

  17. 3D Sisyphus Cooling of Trapped Ions

    Science.gov (United States)

    Ejtemaee, S.; Haljan, P. C.

    2017-07-01

    Using a laser polarization gradient, we realize 3D Sisyphus cooling of Yb+ 171 ions confined in and near the Lamb-Dicke regime in a linear Paul trap. The cooling rate and final mean motional energy of a single ion are characterized as a function of laser intensity and compared to semiclassical and quantum simulations. Sisyphus cooling is also applied to a linear string of four ions to obtain a mean energy of 1-3 quanta for all vibrational modes, an approximately order of magnitude reduction below Doppler cooled energies. This is used to enable subsequent, efficient sideband laser cooling.

  18. Development of Air-cooled Engines with Blower Cooling

    Science.gov (United States)

    Lohner, Kurt

    1933-01-01

    With the aid of a heating device, the heat transfer to cylinders with conical fins of various forms is determined both for shrouded and exposed cylinders. Simultaneously the pressure drop for overcoming the resistance to the motion of air between the fins of the enclosed cylinder is measured. Thus the relations between the heat transfer and the energy required for cooling are discovered. The investigations show that the heat transfer in a conducted air flow is much greater than in a free current and that further improvement, as compared with free exposure, is possible through narrower spaces between the fins.

  19. State of the art of nuclear facilities with organic cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Brede, O.; Nagel, S.; Ziegenbein, D.

    1984-06-01

    USA, Canadian, and USSR activities aimed at developing nuclear facilities with organic cooled reactors are summarized. The facilities OMRE, PNPF, WR-1, and ARBUS are described, discussing in particular the problems of the chemistry of organic coolants. Finally, problems of further development and prospects of the application of organic cooled reactors are briefly outlined.

  20. Smart energy option: Reusing wastewater for cooling energy

    Energy Technology Data Exchange (ETDEWEB)

    Clapham, A. [Boeing Co., Seattle, WA (United States); Jackman, J. [Puget Sound Power and Light Co., Bellevue, WA (United States); Lundt, M.M. [King County Department of Metropolitan Services, Seattle, WA (United States). Water Pollution Control Dept.

    1996-12-31

    The King County Department of Metropolitan Services, an airplane manufacturer, and a Seattle utility are ready to begin operating the first commercial effluent-based cooling system for buildings in the Northwest. This paper details the studies undertaken to design the system and how the manufacturer addressed its employees` concerns about a new system. There are several environmental benefits to using effluent as a cooling medium. Considerable energy savings in chiller operations are achieved because the effluent temperature is 10 to 20 degrees cooler than water returned from cooling towers. Another major benefit is water conservation. Conventional cooling towers would consume several million gallons of water each year. By using effluent, the consumption of this water will be avoided. Water run through cooling towers is treated with chemicals to prevent corrosion and biological growth. With the effluent in a closed-loop system, there will be no need to treat the effluent. Consequently there will be a reduction in use of water treatment chemicals that are ultimately discharged into the sewer system. This reduces the treatment load to the county and helps to maintain a cleaner environment. The concept is simple: recover heat wasted from one activity for reuse in another. The delivery is easy: send effluent via a pipeline to customer`s chillers to pick up heat and return that heat to the plant. The selling of this idea is the focus of this paper.

  1. The Detectability of AGN Cavities in Cooling-Flow Clusters

    CERN Document Server

    Birzan, L; McNamara, B R; Nulsen, P E J; Wise, M W

    2009-01-01

    Chandra X-ray Observatory has revealed X-ray cavities in many nearby cooling flow clusters. The cavities trace feedback from the central active galactic nulceus (AGN) on the intracluster medium (ICM), an important ingredient in stabilizing cooling flows and in the process of galaxy formation and evolution. But, the prevalence and duty cycle of such AGN outbursts is not well understood. To this end, we study how the cooling is balanced by the cavity heating for a complete sample of clusters (the Brightest 55 clusters of galaxies, hereafter B55). In the B55, we found 33 cooling flow clusters, 20 of which have detected X-ray bubbles in their ICM. Among the remaining 13, all except Ophiuchus could have significant cavity power yet remain undetected in existing images. This implies that the duty cycle of AGN outbursts with significant heating potential in cooling flow clusters is at least 60 % and could approach 100 %, but deeper data is required to constrain this further.

  2. Cooling Performance of Natural Circulation for a Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Suki; Chun, J. H.; Yum, S. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    This paper deals with the core cooling performance by natural circulation during normal operation and a flow channel blockage event in an open tank-in-pool type research reactor. The cooling performance is predicted by using the RELAP5/ MOD3.3 code. The core decay heat is usually removed by natural circulation to the reactor pool water in open tank-in-pool type research reactors with the thermal power less than several megawatts. Therefore, these reactors have generally no active core cooling system against a loss of normal forced flow. In reactors with the thermal power less than around one megawatt, the reactor core can be cooled down by natural circulation even during normal full power operation. The cooling performance of natural circulation in an open tank-in-pool type research reactor has been investigated during the normal natural circulation and a flow channel blockage event. It is found that the maximum powers without void generation at the hot channel are around 1.16 MW and 820 kW, respectively, for the normal natural circulation and the flow channel blockage event.

  3. Design Concepts for Cooled Ceramic Matrix Composite Turbine Vanes

    Science.gov (United States)

    Boyle, Robert

    2014-01-01

    This project demonstrated that higher temperature capabilities of ceramic matrix composites (CMCs) can be used to reduce emissions and improve fuel consumption in gas turbine engines. The work involved closely coupling aerothermal and structural analyses for the first-stage vane of a high-pressure turbine (HPT). These vanes are actively cooled, typically using film cooling. Ceramic materials have structural and thermal properties different from conventional metals used for the first-stage HPT vane. This project identified vane configurations that satisfy CMC structural strength and life constraints while maintaining vane aerodynamic efficiency and reducing vane cooling to improve engine performance and reduce emissions. The project examined modifications to vane internal configurations to achieve the desired objectives. Thermal and pressure stresses are equally important, and both were analyzed using an ANSYS® structural analysis. Three-dimensional fluid and heat transfer analyses were used to determine vane aerodynamic performance and heat load distributions.

  4. Detectors and cooling technology for direct spectroscopic biosignature characterization

    CERN Document Server

    Rauscher, Bernard J; Moseley, S H; Sadleir, John E; Stevenson, Thomas

    2016-01-01

    Direct spectroscopic biosignature characterization (hereafter "biosignature characterization") will be a major focus for future space observatories equipped with coronagraphs or starshades. Our aim in this article is to provide an introduction to potential detector and cooling technologies for biosignature characterization. We begin by reviewing the needs. These include nearly noiseless photon detection at flux levels as low as $<0.001~\\textrm{photons}~s^{-1}~\\textrm{pixel}^{-1}$ in the visible and near-IR. We then discuss potential areas for further testing and/or development to meet these needs using non-cryogenic detectors (EMCCD, HgCdTe array, HgCdTe APD array), and cryogenic single photon detectors (MKID arrays and TES microcalorimeter arrays). Non-cryogenic detectors are compatible with the passive cooling that is strongly preferred by coronagraphic missions, but would add non-negligible noise. Cryogenic detectors would require active cooling, but in return deliver nearly quantum limited performance....

  5. Thermal Non-equilibrium Consistent with Widespread Cooling

    Science.gov (United States)

    Winebarger, A.; Lionello, R.; Mikic, Z.; Linker, J.; Mok, Y.

    2014-01-01

    Time correlation analysis has been used to show widespread cooling in the solar corona; this cooling has been interpreted as a result of impulsive (nanoflare) heating. In this work, we investigate wide-spread cooling using a 3D model for a solar active region which has been heated with highly stratified heating. This type of heating drives thermal non-equilibrium solutions, meaning that though the heating is effectively steady, the density and temperature in the solution are not. We simulate the expected observations in narrowband EUV images and apply the time correlation analysis. We find that the results of this analysis are qualitatively similar to the observed data. We discuss additional diagnostics that may be applied to differentiate between these two heating scenarios.

  6. Peltier cooling of fermionic quantum gases.

    Science.gov (United States)

    Grenier, Ch; Georges, A; Kollath, C

    2014-11-14

    We propose a cooling scheme for fermionic quantum gases, based on the principles of the Peltier thermoelectric effect and energy filtering. The system to be cooled is connected to another harmonically trapped gas acting as a reservoir. The cooling is achieved by two simultaneous processes: (i) the system is evaporatively cooled, and (ii) cold fermions from deep below the Fermi surface of the reservoir are injected below the Fermi level of the system, in order to fill the "holes" in the energy distribution. This is achieved by a suitable energy dependence of the transmission coefficient connecting the system to the reservoir. The two processes can be viewed as simultaneous evaporative cooling of particles and holes. We show that both a significantly lower entropy per particle and faster cooling rate can be achieved in this way than by using only evaporative cooling.

  7. Peltier Cooling of Fermionic Quantum Gases

    Science.gov (United States)

    Grenier, Ch.; Georges, A.; Kollath, C.

    2014-11-01

    We propose a cooling scheme for fermionic quantum gases, based on the principles of the Peltier thermoelectric effect and energy filtering. The system to be cooled is connected to another harmonically trapped gas acting as a reservoir. The cooling is achieved by two simultaneous processes: (i) the system is evaporatively cooled, and (ii) cold fermions from deep below the Fermi surface of the reservoir are injected below the Fermi level of the system, in order to fill the "holes" in the energy distribution. This is achieved by a suitable energy dependence of the transmission coefficient connecting the system to the reservoir. The two processes can be viewed as simultaneous evaporative cooling of particles and holes. We show that both a significantly lower entropy per particle and faster cooling rate can be achieved in this way than by using only evaporative cooling.

  8. Status of the Fermilab electron cooling project

    Energy Technology Data Exchange (ETDEWEB)

    Nagaitsev, S. E-mail: nsergei@fnal.gov; Burov, A.; Carlson, K.; Dudnikov, V.; Kramper, B.; Kroc, T.; Leibfritz, J.; McGee, M.; Saewert, G.; Schmidt, C.W.; Shemyakin, A.; Warner, A.; Seletsky, S.; Tupikov, V

    2004-10-11

    A prototype of a 4.3-MeV electron cooling system has been assembled at Fermilab as part of the on-going R and D program in high-energy electron cooling. This electron cooler prototype will not demonstrate the actual cooling but it would allow to determine if the electron beam properties are suitable for antiproton beam cooling. An electron beam is accelerated by a 5-MV Pelletron (Van de Graaff type) accelerator and transported to a prototype cooling section. The cooling would take place in a 20-m long solenoid flanked on both sides by supply and return beam-lines--a total of 60 m of transport channel. This paper describes the status of the electron cooling R and D program.

  9. Provisioning cooling elements for chillerless data centers

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Parida, Pritish R.

    2016-12-13

    Systems and methods for cooling include one or more computing structure, an inter-structure liquid cooling system that includes valves configured to selectively provide liquid coolant to the one or more computing structures; a heat rejection system that includes one or more heat rejection units configured to cool liquid coolant; and one or more liquid-to-liquid heat exchangers that include valves configured to selectively transfer heat from liquid coolant in the inter-structure liquid cooling system to liquid coolant in the heat rejection system. Each computing structure further includes one or more liquid-cooled servers; and an intra-structure liquid cooling system that has valves configured to selectively provide liquid coolant to the one or more liquid-cooled servers.

  10. Tropical cyclone cooling combats region-wide coral bleaching.

    Science.gov (United States)

    Carrigan, Adam D; Puotinen, Marji

    2014-05-01

    Coral bleaching has become more frequent and widespread as a result of rising sea surface temperature (SST). During a regional scale SST anomaly, reef exposure to thermal stress is patchy in part due to physical factors that reduce SST to provide thermal refuge. Tropical cyclones (TCs - hurricanes, typhoons) can induce temperature drops at spatial scales comparable to that of the SST anomaly itself. Such cyclone cooling can mitigate bleaching across broad areas when well-timed and appropriately located, yet the spatial and temporal prevalence of this phenomenon has not been quantified. Here, satellite SST and historical TC data are used to reconstruct cool wakes (n=46) across the Caribbean during two active TC seasons (2005 and 2010) where high thermal stress was widespread. Upon comparison of these datasets with thermal stress data from Coral Reef Watch and published accounts of bleaching, it is evident that TC cooling reduced thermal stress at a region-wide scale. The results show that during a mass bleaching event, TC cooling reduced thermal stress below critical levels to potentially mitigate bleaching at some reefs, and interrupted natural warming cycles to slow the build-up of thermal stress at others. Furthermore, reconstructed TC wave damage zones suggest that it was rare for more reef area to be damaged by waves than was cooled (only 12% of TCs). Extending the time series back to 1985 (n = 314), we estimate that for the recent period of enhanced TC activity (1995-2010), the annual probability that cooling and thermal stress co-occur is as high as 31% at some reefs. Quantifying such probabilities across the other tropical regions where both coral reefs and TCs exist is vital for improving our understanding of how reef exposure to rising SSTs may vary, and contributes to a basis for targeting reef conservation.

  11. Confirmation of shutdown cooling effects

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kotaro, E-mail: ksato@nelted.co.jp; Tabuchi, Masato; Sugimura, Naoki; Tatsumi, Masahiro [Nuclear Engineering, Limited, 1-3-7 Tosabori Nishi-ku, Osaka-shi, Osaka 550-0001 (Japan)

    2015-12-31

    After the Fukushima accidents, all nuclear power plants in Japan have gradually stopped their operations and have long periods of shutdown. During those periods, reactivity of fuels continues to change significantly especially for high-burnup UO{sub 2} fuels and MOX fuels due to radioactive decays. It is necessary to consider these isotopic changes precisely, to predict neutronics characteristics accurately. In this paper, shutdown cooling (SDC) effects of UO{sub 2} and MOX fuels that have unusual operation histories are confirmed by the advanced lattice code, AEGIS. The calculation results show that the effects need to be considered even after nuclear power plants come back to normal operation.

  12. Hot moons and cool stars

    Directory of Open Access Journals (Sweden)

    Heller René

    2013-04-01

    Full Text Available The exquisite photometric precision of the Kepler space telescope now puts the detection of extrasolar moons at the horizon. Here, we firstly review observational and analytical techniques that have recently been proposed to find exomoons. Secondly, we discuss the prospects of characterizing potentially habitable extrasolar satellites. With moons being much more numerous than planets in the solar system and with most exoplanets found in the stellar habitable zone being gas giants, habitable moons could be as abundant as habitable planets. However, satellites orbiting planets in the habitable zones of cool stars will encounter strong tidal heating and likely appear as hot moons.

  13. Assessment of spent fuel cooling

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra, J.G.; Jones, W.R.; Lanik, G.F. [and others

    1997-02-01

    The paper presents the methodology, the findings, and the conclusions of a study that was done by the Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) on loss of spent fuel pool cooling. The study involved an examination of spent fuel pool designs, operating experience, operating practices, and procedures. AEOD`s work was augmented in the area of statistics and probabilistic risk assessment by experts from the Idaho Nuclear Engineering Laboratory. Operating experience was integrated into a probabilistic risk assessment to gain insight on the risks from spent fuel pools.

  14. Thermoelectric Devices Cool, Power Electronics

    Science.gov (United States)

    2009-01-01

    Nextreme Thermal Solutions Inc., based in Research Triangle Park, North Carolina, licensed thermoelectric technology from NASA s Jet Propulsion Laboratory. This has allowed the company to develop cutting edge, thin-film thermoelectric coolers that effective remove heat generated by increasingly powerful and tightly packed microchip components. These solid-state coolers are ideal solutions for applications like microprocessors, laser diodes, LEDs, and even potentially for cooling the human body. Nextreme s NASA technology has also enabled the invention of thermoelectric generators capable of powering technologies like medical implants and wireless sensor networks.

  15. Biofouling Control in Cooling Water

    Directory of Open Access Journals (Sweden)

    T. Reg Bott

    2009-01-01

    Full Text Available An important aspect of environmental engineering is the control of greenhouse gas emissions. Fossil fuel-fired power stations, for instance, represent a substantial contribution to this problem. Unless suitable steps are taken the accumulation of microbial deposits (biofouling on the cooling water side of the steam condensers can reduce their efficiency and in consequence, the overall efficiency of power production, with an attendant increase in fuel consumption and hence CO2 production. Biofouling control, therefore, is extremely important and can be exercised by chemical or physical techniques or a combination of both. The paper gives some examples of the effectiveness of different approaches to biofouling control.

  16. Information technology equipment cooling system

    Science.gov (United States)

    Schultz, Mark D.

    2014-06-10

    According to one embodiment, a system for removing heat from a rack of information technology equipment may include a sidecar indoor air to liquid heat exchanger that cools warm air generated by the rack of information technology equipment. The system may also include a liquid to liquid heat exchanger and an outdoor heat exchanger. The system may further include configurable pathways to connect and control fluid flow through the sidecar heat exchanger, the liquid to liquid heat exchanger, the rack of information technology equipment, and the outdoor heat exchanger based upon ambient temperature and/or ambient humidity to remove heat from the rack of information technology equipment.

  17. Theoretical insight of adsorption cooling

    KAUST Repository

    Chakraborty, Anutosh

    2011-06-03

    This letter proposes and presents a thermodynamic formulation to calculate the energetic performances of an adsorption cooler as a function of pore widths and volumes of solid adsorbents. The simulated results in terms of the coefficient of performance are validated with experimental data. It is found from the present analysis that the performance of an adsorption cooling device is influenced mainly by the physical characteristics of solid adsorbents, and the characteristics energy between the adsorbent-adsorbate systems. The present study confirms that there exists a special type of silicagel having optimal physical characteristics that allows us to obtain the best performance.

  18. Ionization Cooling using Parametric Resonances

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland P.

    2008-06-07

    Ionization Cooling using Parametric Resonances was an SBIR project begun in July 2004 and ended in January 2008 with Muons, Inc., (Dr. Rolland Johnson, PI), and Thomas Jefferson National Accelerator Facility (JLab) (Dr. Yaroslav Derbenev, Subcontract PI). The project was to develop the theory and simulations of Parametric-resonance Ionization Cooling (PIC) so that it could be used to provide the extra transverse cooling needed for muon colliders in order to relax the requirements on the proton driver, reduce the site boundary radiation, and provide a better environment for experiments. During the course of the project, the theoretical understanding of PIC was developed and a final exposition is ready for publication. Workshops were sponsored by Muons, Inc. in May and September of 2007 that were devoted to the PIC technique. One outcome of the workshops was the interesting and somewhat unexpected realization that the beam emittances using the PIC technique can get small enough that space charge forces can be important. A parallel effort to develop our G4beamline simulation program to include space charge effects was initiated to address this problem. A method of compensating for chromatic aberrations by employing synchrotron motion was developed and simulated. A method of compensating for spherical aberrations using beamline symmetry was also developed and simulated. Different optics designs have been developed using the OptiM program in preparation for applying our G4beamline simulation program, which contains all the power of the Geant4 toolkit. However, no PIC channel design that has been developed has had the desired cooling performance when subjected to the complete G4beamline simulation program. This is believed to be the consequence of the difficulties of correcting the aberrations associated with the naturally large beam angles and beam sizes of the PIC method that are exacerbated by the fringe fields of the rather complicated channel designs that have been

  19. Belowground productivity of two cool desert communities.

    Science.gov (United States)

    Caldwell, M M; Camp, L B

    1974-06-01

    A new technique based upon the dilution of C (14) /C (12) ratios in structural carbon of root systems during the course of the growing season was used to evaluate belowground turnover or productivity of two cool desert communities in northern Utah, USA. This technique provides a measure of turnover of the root system of established perennial plant communities avoiding many of the disadvantages of other techniques. Adjacent communities dominated by Atriplex confertifolia and Ceratoides lanata both exhibited belowground productivity values exceeding aboveground production by three-fold. The greater belowground turnover of the Atriplex-dominated community may be a factor contributing to the maintenance of a greater quantity of aboveground biomass and prolonged periods of active photosynthesis during the driest portions of the year when Ceratoides becomes largely photosynthetically inactive.

  20. Cooling and Heating Solid Quark Stars

    CERN Document Server

    Yu, Meng

    2009-01-01

    We present here a phenomenological solid quark star pulsar model to interpret the observed thermal X-ray emission of isolated pulsars. The heat capacity for solid quark stars was found to be quite small, so that the residual internal stellar heat gained at the birth of the star could be dissipated in an extremely short timescale. However, the bombardment induced by backflowing plasma at the poles of solid quark stars would get the stars be reheated, so that long term soft X-ray emission can be sustained. Such a scenario could be used for those X-ray pulsars with significant magnetospheric activities, and their cooling processes would thus be established. Dim X-ray isolated neutron stars (XDINs) as well as compact central objects (CCOs) have been observed with dominant soft X-ray radiation combined with little magnetospheric manifestations. Such sources could be solid quark stars accreting in the propeller regime.

  1. Enhancing the efectiveness of film cooling

    Institute of Scientific and Technical Information of China (English)

    Tom I-P.Shih; Sangkwon Na

    2007-01-01

    Advanced gas turbine stages are designed to operate at increasingly higher inlet temperatures to increase thermal efficiency and specific power output.To maintain durability and reasonable life,film cooling is needed in addition to internal cooling,especially for the first stage.Film cooling lowers material temperature by forced convection inside film-cooling holes and by forming a layer of coolant about component surfaces to insulate them from the hot gases.Unfortunately,each cooling jet forms a pair of counter-rotating vortices that entrains hot gas and causes the film-cooling jet to lift off from the surface that it is intended to protect.This paper gives an overview of efforts to enhance the effectiveness of film-cooling.This paper also describes two new design concepts.One design concept seeks to minimize the entrainment of hot gases underneath of film-cooling jets by using flow-aligned blockers.The other design concept shifts the interaction between the approaching hot gas and the cooling jet to occur further above the surface by using an upstream ramp.For both design concepts,computational fluid dynamics results are presented to examine their usefulness in enhancing film-cooling effectiveness.

  2. 2004 Savannah River Cooling Tower Collection (U)

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, Alfred [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Parker, Matthew J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Villa-Aleman, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2005-05-01

    The Savannah River National Laboratory (SRNL) collected ground truth in and around the Savannah River Site (SRS) F-Area cooling tower during the spring and summer of 2004. The ground truth data consisted of air temperatures and humidity inside and around the cooling tower, wind speed and direction, cooling water temperatures entering; inside adn leaving the cooling tower, cooling tower fan exhaust velocities and thermal images taken from helicopters. The F-Area cooling tower had six cells, some of which were operated with fans off during long periods of the collection. The operating status (fan on or off) for each of the six cells was derived from operations logbooks and added to the collection database. SRNL collected the F-Area cooling tower data to produce a database suitable for validation of a cooling tower model used by one of SRNL's customer agencies. SRNL considers the data to be accurate enough for use in a model validation effort. Also, the thermal images of the cooling tower decks and throats combined with the temperature measurements inside the tower provide valuable information about the appearance of cooling towers as a function of fan operating status and time of day.

  3. Dry cooling tower with water augmentation

    Energy Technology Data Exchange (ETDEWEB)

    Ireland, R.G.; Tramontini, V.N.

    1981-06-23

    An air cooling tower system is disclosed for condensing exhaust steam in power plants, that has water cooling augmentation to maintain the plant cooling capacity during high atmospheric temperature periods. The cooling tower includes a plurality of banks of brazed aluminum plate and fin type heat exchangers arranged in inverted ''v'' shaped sets. These heat exchangers cool ammonia used as the cooling fluid in the primary condenser for the power plant turbine exhaust steam. Each of these heat exchangers has a core consisting of a plurality of parallel aluminum plates spaced apart by fin assemblies that define a plurality of fluid passes. Approximately every other one of these passes has closed sides that open at the ends of the core to headers and define ammonia passes. The passes adjacent the ammonia passes are open at the sides and define air passes that permit the free flow of air transversely through the heat exchanger cores. An additional pass is provided adjacent every fourth one of the ammonia passes and these have closed sides and ends and define the passes for the cooling water. The water passes communicate at the bottom of the core with a water inlet manifold and at the top of the core with a water outlet manifold. The cooling tower system is designed so that at 55 degrees fahrenheit air temperatures or below, the cooling air alone will provide the necessary cooling for the ammonia to satisfy plant requirements. Above 55 degrees fahrenheit air temperature, cooling water from a separate water tank is pumped through the water passes to provide an additional cooling effect to maintain the design cooling capacity.

  4. Active cooling convectors in the ''Altstadt-Palais'' building. Feng Shui criteria and users' wishes were considered; Aktive Kuehlkonvektoren im Altstadt-Palais. Feng Shui-Kriterien und Nutzerwuensche beruecksichtigen

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Wolfgang

    2009-07-01

    Modern air conditioning systems are not chosen for technical and economic aspects alone, but there are various boundary conditions that are generally considered. In the case of the Altstadt-Palais building at Karl-Scharnagl-Ring, Munich, which has an office floor space of about 9,800 m{sup 2}, also Feng Shui criteria were taken into account apart from 'normal' criteria like room flexibility, thermal comfort, and economic efficiency. The new system has cooling convectors with primary air supply that are integrated in the ceilings. (orig.)

  5. Heating and Cooling Protostellar Disks

    CERN Document Server

    Hirose, S

    2011-01-01

    We examine heating and cooling in protostellar disks using 3-D radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized by stellar X-rays, well-coupled to magnetic fields, and sustains a turbulent accretion flow driven by magneto-rotational instability, while the interior is resistive and magnetically dead. The turbulent layers heat by absorbing the light from the central star and by dissipating the magnetic fields. They are optically-thin to their own radiation and cool inefficiently. The optically-thick interior in contrast is heated only weakly, by re-emission from the atmosphere. The interior is colder than a classical viscous model, and isothermal. The magnetic fields support an extended atmosphere that absorbs the starlight 1.5 times higher than the hydrostatic viscous model. The disk thickness thus measures not the internal temperature, but the magnetic field strength. Fluctuations i...

  6. Thermodynamics of Quantum Feedback Cooling

    Directory of Open Access Journals (Sweden)

    Pietro Liuzzo-Scorpo

    2016-02-01

    Full Text Available The ability to initialize quantum registers in pure states lies at the core of many applications of quantum technologies, from sensing to quantum information processing and computation. In this paper, we tackle the problem of increasing the polarization bias of an ensemble of two-level register spins by means of joint coherent manipulations, involving a second ensemble of ancillary spins and energy dissipation into an external heat bath. We formulate this spin refrigeration protocol, akin to algorithmic cooling, in the general language of quantum feedback control, and identify the relevant thermodynamic variables involved. Our analysis is two-fold: on the one hand, we assess the optimality of the protocol by means of suitable figures of merit, accounting for both its work cost and effectiveness; on the other hand, we characterise the nature of correlations built up between the register and the ancilla. In particular, we observe that neither the amount of classical correlations nor the quantum entanglement seem to be key ingredients fuelling our spin refrigeration protocol. We report instead that a more general indicator of quantumness beyond entanglement, the so-called quantum discord, is closely related to the cooling performance.

  7. Heat pipe turbine vane cooling

    Energy Technology Data Exchange (ETDEWEB)

    Langston, L.; Faghri, A. [Univ. of Connecticut, Storrs, CT (United States)

    1995-10-01

    The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and an uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

  8. Weighing Ultra-Cool Stars

    Science.gov (United States)

    2004-05-01

    Large Ground-Based Telescopes and Hubble Team-Up to Perform First Direct Brown Dwarf Mass Measurement [1] Summary Using ESO's Very Large Telescope at Paranal and a suite of ground- and space-based telescopes in a four-year long study, an international team of astronomers has measured for the first time the mass of an ultra-cool star and its companion brown dwarf. The two stars form a binary system and orbit each other in about 10 years. The team obtained high-resolution near-infrared images; on the ground, they defeated the blurring effect of the terrestrial atmosphere by means of adaptive optics techniques. By precisely determining the orbit projected on the sky, the astronomers were able to measure the total mass of the stars. Additional data and comparison with stellar models then yield the mass of each of the components. The heavier of the two stars has a mass around 8.5% of the mass of the Sun and its brown dwarf companion is even lighter, only 6% of the solar mass. Both objects are relatively young with an age of about 500-1,000 million years. These observations represent a decisive step towards the still missing calibration of stellar evolution models for very-low mass stars. PR Photo 19a/04: Orbit of the ultra-cool stars in 2MASSW J0746425+2000321. PR Photo 19b/04: Animated Gif of the orbital motion. Telephone number star Even though astronomers have found several hundreds of very low mass stars and brown dwarfs, the fundamental properties of these extreme objects, such as masses and surface temperatures, are still not well known. Within the cosmic zoo, these ultra-cool stars represent a class of "intermediate" objects between giant planets - like Jupiter - and "normal" stars less massive than our Sun, and to understand them well is therefore crucial to the field of stellar astrophysics. The problem with these ultra-cool stars is that contrary to normal stars that burn hydrogen in their central core, no unique relation exists between the luminosity of the

  9. Influence of solar variability on the infrared radiative cooling of the thermosphere from 2002 to 2014.

    Science.gov (United States)

    Mlynczak, Martin G; Hunt, Linda A; Mertens, Christopher J; Thomas Marshall, B; Russell, James M; Woods, Thomas; Earl Thompson, R; Gordley, Larry L

    2014-04-16

    Infrared radiative cooling of the thermosphere by carbon dioxide (CO2, 15 µm) and by nitric oxide (NO, 5.3 µm) has been observed for 12 years by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite. For the first time we present a record of the two most important thermospheric infrared cooling agents over a complete solar cycle. SABER has documented dramatic variability in the radiative cooling on time scales ranging from days to the 11 year solar cycle. Deep minima in global mean vertical profiles of radiative cooling are observed in 2008-2009. Current solar maximum conditions, evidenced in the rates of radiative cooling, are substantially weaker than prior maximum conditions in 2002-2003. The observed changes in thermospheric cooling correlate well with changes in solar ultraviolet irradiance and geomagnetic activity during the prior maximum conditions. NO and CO2 combine to emit 7 × 10(18) more Joules annually at solar maximum than at solar minimum. First record of thermospheric IR cooling rates over a complete solar cycleIR cooling in current solar maximum conditions much weaker than prior maximumVariability in thermospheric IR cooling observed on scale of days to 11 years.

  10. Reduction in body temperature using hand cooling versus passive rest after exercise in the heat.

    Science.gov (United States)

    Adams, William M; Hosokawa, Yuri; Adams, Elizabeth L; Belval, Luke N; Huggins, Robert A; Casa, Douglas J

    2016-11-01

    To examine the effects of hydration and hand cooling on lowering body temperature after exercise in the heat. Randomized cross-over design. Nine recreationally active male participants (mean±SD; age, 24±4; height, 177.3±9.9cm; body mass, 76.7±11.6kg; body fat, 14.7±5.8%) completed a bout of treadmill exercise in a hot environment. After completion of exercise, participants were assigned to the following trials for post-exercise cooling: (1) hydrated with passive rest (HY), (2) hydrated with hand cooling on both hands (HY+2HC), (3) dehydrated with passive rest (DY), and (4) dehydrated with hand cooling on both hands (DY+2HC). Within subject differences were assessed using a three-way (Hydration×Condition×Time) repeated measures ANOVA with Tukey's post hoc analysis if significant interactions were found. Irrespective of hydration status, hand cooling on both hands resulted in significantly greater reductions in TREC than passive cooling at minute 20 (0.27°C [0.05, 0.49], ES=2.08, p=0.017) (Fig. 1). The reduction in TREC at minute 18 trended towards statistical significance (0.21°C [.003, .42], ES=1.59, p=0.053). Hydration status alone and when differentiated among modes of cooling showed no differences on changes of TREC or heart rate across all conditions during post exercise recovery (p>0.05). Hand cooling on both hands reduced TREC more than passive cooling, however, the cooling rates observed render hand cooling a poor option for cooling. Greater reductions in TREC after exercise or between bouts of exercise may enhance recovery and subsequent performance. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. Convection versus conduction cooling for induction of mild hypothermia during neurovascular procedures in adults.

    Science.gov (United States)

    Théard, M A; Tempelhoff, R; Crowder, C M; Cheng, M A; Todorov, A; Dacey, R G

    1997-07-01

    Hypothermia for cerebral protection is usually achieved by administration of intravenous fluids at room temperature, cooling ambient air, ice packs, and a temperature-adjustable circulating water mattress. We compared cooling by conduction by using a water mattress to cool by convection by using a forced-air cooling device. Twenty patients were prospectively randomized to two groups: 10 patients cooled by convection (CC) and 10 patients cooled by traditional methods (TC). Two patients in the CC group were withdrawn from the study and excluded from the analysis; one patient for failure to cool despite the use of both techniques, and the other for the abrupt onset of arrhythmias and myocardial depression during hypothermia. Temperature was measured at the tympanic membrane, pulmonary artery, and esophageal probe sites and recorded every 15 min. The time required to reach the target temperature range of 33-34 degrees C was recorded. We found no differences in the temperatures measured at the three sites during cooling and rewarming. Baseline temperatures recorded from the pulmonary artery catheter before beginning "active cooling" were similar in both groups (TC, 35.0 +/- 0.2 degrees C vs. CC, 35.3 +/- 0.1 degrees C). We found no difference in the time to target temperature between TC and CC (TC, 178 +/- 25 min vs. CC, 142 +/- 21 min). One patient had some arrhythmias on cooling in the convective group, but her preoperative condition may have been responsible. In conclusion, cooling by convection appears to be a safe alternative to conduction cooling.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-01

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

  13. Teaching Social Communication Skills Using a Cool versus Not Cool Procedure plus Role-Playing and a Social Skills Taxonomy

    Science.gov (United States)

    Leaf, Justin B.; Taubman, Mitchell; Milne, Christine; Dale, Stephanie; Leaf, Jeremy; Townley-Cochran, Donna; Tsuji, Kathleen; Kassardjian, Alyne; Alcalay, Aditt; Leaf, Ronald; McEachin, John

    2016-01-01

    We utilized a cool versus not cool procedure plus role-playing to teach social communication skills to three individuals diagnosed with autism spectrum disorder. The cool versus not cool procedure plus role-playing consisted of the researcher randomly demonstrating the behavior correctly (cool) two times and the behavior incorrectly (not cool) two…

  14. Teaching Social Communication Skills Using a Cool versus Not Cool Procedure plus Role-Playing and a Social Skills Taxonomy

    Science.gov (United States)

    Leaf, Justin B.; Taubman, Mitchell; Milne, Christine; Dale, Stephanie; Leaf, Jeremy; Townley-Cochran, Donna; Tsuji, Kathleen; Kassardjian, Alyne; Alcalay, Aditt; Leaf, Ronald; McEachin, John

    2016-01-01

    We utilized a cool versus not cool procedure plus role-playing to teach social communication skills to three individuals diagnosed with autism spectrum disorder. The cool versus not cool procedure plus role-playing consisted of the researcher randomly demonstrating the behavior correctly (cool) two times and the behavior incorrectly (not cool) two…

  15. Free Cooling in the Water Cooling Towers: a Case Study for Istanbul, Turkey

    OpenAIRE

    KOÇ, İbrahim; PARMAKSIZOGLU, Cem

    2013-01-01

    Energy saving in cooling towers which is used for cooling to the hot water can be significantly improved by using free cooling application. This application is commonly known economizer cycle and when outside conditions are suitable for cooling, it is used for. In this study, the free cooling is applied for the cold water necessity which is supplied by the chiller of the cooling tower in the factory which is available in Istanbul. The results show that the ...

  16. Comparison of Air Cooled and Evaporatively Cooled Refrigerartion Systems – A Review Paper

    Directory of Open Access Journals (Sweden)

    V. V. Birangane

    2014-06-01

    Full Text Available The air cooled condensers are widely used as they are less costly and give satisfactory performance. But their performance is greatly affected by the temperature of cooling media which is ambient air. To deal this problem we can use water cooled condenser. But their cost and maintenance limit their use. The performance improvement of Air cooled condensers can be achieved by using evaporative cooling. This method may prove quiet effective and less costly. There are researchers working on the above issue. Few of them have successfully implemented the research in practice. The paper deals with a few papers using the evaporative cooling. The applications include domestic as well as industrial.

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

    Science.gov (United States)

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

    2014-07-01

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

  18. AGN-stimulated Cooling of Hot Gas in Elliptical Galaxies

    CERN Document Server

    Valentini, Milena

    2015-01-01

    We study the impact of relatively weak AGN feedback on the interstellar medium of intermediate and massive elliptical galaxies. We find that the AGN activity, while globally heating the ISM, naturally stimulates some degree of hot gas cooling on scales of several kpc. This process generates the persistent presence of a cold ISM phase, with mass ranging between 10$^4$ and $\\gtrsim$ 5 $\\times$ 10$^7$ M$_\\odot$, where the latter value is appropriate for group centered, massive galaxies. Widespread cooling occurs where the ratio of cooling to free-fall time before the activation of the AGN feedback satisfies $t_{cool}/t_{ff} \\lesssim 70$, that is we find a less restrictive threshold than commonly quoted in the literature. This process helps explaining the body of observations of cold gas (both ionized and neutral/molecular) in Ellipticals and, perhaps, the residual star formation detected in many early-type galaxies. The amount and distribution of the off-center cold gas vary irregularly with time. The cold ISM v...

  19. Interactions among cooling, fungicide and postharvest ripening temperature on peaches

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Trujillo, J. Pablo; Cano, Antonio; Artes, Francisco [Postharvest and refrigeration Lab., Dept. of Food Science and Technology, CEBAS-CSIC, Murcia (Spain)

    2000-07-01

    Peach fruit (Prunus persica L. cv. 'Miraflores') harvested at the firm-ripe stage, treated or not with 2 g l{sup -1} iprodione, were cooled or not at 1{sup o}C and ripened at 15 or 20{sup o}C and 95% RH for 10 days. During ripening, weight loss, fungal development and changes in quality parameters (firmness, soluble solids content, titratable acidity, pH and ground and flesh color), and carbon dioxide and ethylene production were monitored. Cooling alone or combined with iprodione avoided Rhizopus nigricans decay during ripening at either ripening temperatures. A skin damage not previously reported on fungicide treated peach was observed at 20{sup o}C. Cooled fruit ripened at 15{sup o}C showed an anomalous respiration rate and ethylene production after the climacteric peak, a loss of firmness and a drop in titratable acidity after 7 days of storage, and reduced endo-polygalacturonase activity in presence of continuous pectinmethylesterase activity during the first week. Cooling before ripening at 20{sup o}C led to the best flavor without excessive total losses. These results helped in the optimization of warming cycles during cold storage used to avoid chilling injuries development on peaches. (Author)

  20. MEIC Electron Cooling Simulation Using Betacool

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, He [JLAB; Zhang, Yuhong [JLAB

    2013-12-01

    Electron cooling of ion beams is the most critical R&D issue in Jefferson Lab's MEIC design. In the ion collider ring, a bunched electron beam driven by an energy-recovery SRF linac assisted by a circulate ring will be employed to cool protons or ions with energies up to 100 GeV/u, a parameter regime that electron cooling has never been applied. It is essential to understand how efficient the electron cooling is, particularly in the high energy range, to confirm the feasibility of the design. Electron cooling is also important in LEIC design although the ion energy is 25 GeV/u, lower than MEIC. In this paper, we will present first results of the simulation studies of electron cooling processes in the collider ring of both MEIC and LEIC using BETACOOL code.

  1. Complete Muon Cooling Channel Design and Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, C. [MUONS Inc., Batavia; Ankenbrandt, C. [MUONS Inc., Batavia; Johnson, R. P. [MUONS Inc., Batavia; Derbenev, Y. [Jefferson Lab; Morozov, V. [Jefferson Lab; Neuffer, D. [Fermilab; Yonehara, K. [Fermilab

    2013-06-01

    While considerable progress has been made in developing promising subsystems for muon beam cooling channels to provide the extraordinary reduction of emittances, there is no end-to-end design that is capable of matching between or within the various subsystems. We present concepts to match emittances between and within muon beam cooling subsystems via the Helical Cooling Channel (HCC), which allows a general analytic approach to guide designs of transitions from one set of cooling channel parameters to another. These principles are demonstrated between segments in an existing cooling channel design, resulting in better performance (elimination of particle losses and colder muons) achieved in a channel approximately half its original length! These techniques will allow for a design of a complete cooling channel in a Muon Collider (MC) applicable to a Higgs Factory and an Energy Frontier machine.

  2. Sequential cooling insert for turbine stator vane

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Russel B

    2017-04-04

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

  3. Hot gas path component cooling system

    Science.gov (United States)

    Lacy, Benjamin Paul; Bunker, Ronald Scott; Itzel, Gary Michael

    2014-02-18

    A cooling system for a hot gas path component is disclosed. The cooling system may include a component layer and a cover layer. The component layer may include a first inner surface and a second outer surface. The second outer surface may define a plurality of channels. The component layer may further define a plurality of passages extending generally between the first inner surface and the second outer surface. Each of the plurality of channels may be fluidly connected to at least one of the plurality of passages. The cover layer may be situated adjacent the second outer surface of the component layer. The plurality of passages may be configured to flow a cooling medium to the plurality of channels and provide impingement cooling to the cover layer. The plurality of channels may be configured to flow cooling medium therethrough, cooling the cover layer.

  4. Broadband optical cooling of molecular rotors

    CERN Document Server

    Lien, Chien-Yu; Odom, Brian C

    2014-01-01

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

  5. Fast cooling techniques for gravitational wave antennas

    CERN Document Server

    Furtado, S R

    2002-01-01

    The resonant-mass technique for the detection of gravitational waves may involve, in the near future, the cooling of very large masses (about 100 tons) from room temperature (300 K) to extreme cryogenic temperatures (20 mK). To cool these detectors to cryogenic temperatures an exchange gas (helium) is used, and the heat is removed from the antenna to the cold reservoir by thermal conduction and natural convection. With the current technique, cooling times of about 1 month can be obtained for cylindrical bar antennas of 2.5 tons. Should this same technique be used to cool a 100 ton spherical antenna the cooling time would be about 10 months, making the operation of these antennas impracticable. In this paper, we study the above-mentioned cooling technique and others, such as thermal switching and forced convection from room temperature to liquid nitrogen temperature (77 K) using an aluminium truncated icosahedron of 19 kg weight and 25 cm diameter.

  6. Time-dependent Cooling in Photoionized Plasma

    Science.gov (United States)

    Gnat, Orly

    2017-02-01

    I explore the thermal evolution and ionization states in gas cooling from an initially hot state in the presence of external photoionizing radiation. I compute the equilibrium and nonequilibrium cooling efficiencies, heating rates, and ion fractions for low-density gas cooling while exposed to the ionizing metagalactic background radiation at various redshifts (z = 0 ‑ 3), for a range of temperatures (108–104 K), densities (10‑7–103 cm‑3), and metallicities (10‑3–2 times solar). The results indicate the existence of a threshold ionization parameter, above which the cooling efficiencies are very close to those in photoionization equilibrium (so that departures from equilibrium may be neglected), and below which the cooling efficiencies resemble those in collisional time-dependent gas cooling with no external radiation (and are thus independent of density).

  7. Bubble heating in Extreme Cooling Clusters

    Science.gov (United States)

    Allen, Steven

    2007-09-01

    Our proposal targets `extreme cooling' clusters: those systems with the largest, fastest cooling rates that most severely challenge the AGN-heating paradigm for cluster cores. By targeting two X-ray bright `extreme cooling cluters' with the clearest radio bubbles in their cores, we seek to establish whether it is possible for AGN heating to balance cooling in such systems. If cooling is not balanced by some heat source, then large residual cooling rates should be detectable in the spectral X-ray data. We will measure the bubble properties precisely and map the spatial-spectral structure of the surrounding X-ray gas, searching for ghost bubbles, shocks, ripples, fronts and non-thermal emission.

  8. INFLUENCE OF CUTTING ZONE COOLING METHOD ON CHIP FORMING CONDITIONS

    Directory of Open Access Journals (Sweden)

    E. E. Feldshtein

    2014-01-01

    Full Text Available The paper considers an influence of a cutting zone cooling method on the chip shape and thickening ratio while turning R35 steel with the hardness of НВ 1250 МРа. Cutting with various types of cooling - dry, compressed air and emulsion fog has been investigated in the paper. OPORTET RG-2 emulsol with emulsion concentration of 4% has been used as an active substation. Cutting tool is a turning cutter with a changeable square plate SNUN120408 made of Р25 hard alloy with multilayer wear-resistant coating, upper titanium nitride layer. Front plate surface is flat. Range of cutting speeds - 80-450 m/min, motions - 0,1-0,5 mm/rev, emulsion flow - 1,5-3,5 g/min and compressed air - 4,5-7,0 m3/h, cutting depth - 1,0 mm. In order to reduce a number of single investigations it is possible to use plans based on ЛПх-sequences.It has been shown that the method for cutting zone cooling exerts significant influence on conditions for chip formation. Regression equation describing influence of machining conditions on Ка-chip thickening ratio has been obtained in the paper. The range of cutting modes is extended while using emulsion fog for cooling. In the process of these modes chip is formed in the shape of short spiral fragments or elements. Favourable form of chips is ensured while using the following rate of emulsion - not more than 2 g/min. The investigations have made it possible to determine conditions required for cooling emulsion fog. In this case it has been observed minimum values in chip thickening ratio and chip shape that ensures its easy removal from cutting zone. While making dry turning values of Ка is higher not less than 15 % in comparison with other methods for cutting zone cooling.

  9. Proposal of cooling plant, for SPIDER and MITICA experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fellin, F., E-mail: francesco.fellin@igi.cnr.it [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy); Marcuzzi, D.; Zaccaria, P. [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy); Agarici, G. [Fusion for Energy, ITER Department, Heating and CD, Josep Pla, 2 Torres Diagonal Litoral B3 E- 08019, Barcelona (Spain)

    2011-10-15

    This paper presents a proposal of Cooling Plant for two new Neutral Beam experiments called MITICA and SPIDER to be realized in Padova (Italy). A large amount of Power (up to 70 MW) has to be removed from in-vessel components and auxiliary systems belonging to these two experiments. Different experimental scenarios (pulse duration ranging from few seconds up to 3600 s), requirements for operating temperature, coolant quality and voltage holding are taken into account in this conceptual design proposal. To reduce the radiological risks due to possible presence of activated corrosion products (ACP) in some water cooled components suitable design choices have been analysed. This work was carried out by considering carefully a lot of different aspects like operability, standardization of components, maintenance and repair, optimization of the installed power and the overall costs of the plant. Experiment components with similar requirements are grouped in the same primary circuits where fine temperature regulation, water quality monitoring and calorimetric measurements are the main characteristics. Each primary circuit (PC) is connected to secondary circuits which allow thermal dissipation and, in some cases, also component preheating. Secondary circuits are connected to two large basins the water of which is cooled down by active cooling rejection system such as cooling towers and air coolers. In this way the requirement for impulsive heat dissipation is fulfilled by the water basins allowing to install a less powerful active rejection system and so reducing the total costs. A large effort was done to guarantee good plant integration with the Experiment Main Hall (in which MITICA and SPIDER are located) and other technical supplies, buildings and areas. Other special requirements for stand-alone systems like Draining and Drying System, Pressure Test System and Chemical Control System are also part of this work.

  10. Peltier Junction heats and cools car seat

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalk, M.A.

    1994-10-10

    Electrically heated seats may soon become heated and cooled seats. The design called the CCS module exploits the heat-pump capability of a class of semiconductor thermoelectric devices (TEDs) known as Peltier Junction. Every CCS module contain two TEDs. Heating and cooling occurs through convection and conduction. The heart of the system is the thermoelectric heat pump. This is originally conceived as the sole heating/cooling options for a prototype electric vehicle.

  11. Hot Strip Laminar Cooling Control Model

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; WANG Guo-dong; LIU Xiang-hua

    2004-01-01

    The control model of laminar cooling system for hot strip, including air-cooling model, water-cooling model, temperature distribution model along thickness direction, feedforward control model, feedback control model and self-learning model, was introduced. PID arithmetic and Smith predictor controller were applied to feedback control. The sample of model parameter classification was given. The calculation process was shown by flow chart. The model has been proved to be simple, effective and of high precision.

  12. Constraint Cooling of Hot Rolled Coil

    Institute of Scientific and Technical Information of China (English)

    WANG Li-juan; ZHANG Chun-li

    2004-01-01

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

  13. Solar heat utilization for adsorption cooling device

    Directory of Open Access Journals (Sweden)

    Malcho Milan

    2012-04-01

    Full Text Available This article deals with possibility of solar system connection with adsorption cooling system. Waste heat from solar collectors in summer is possible to utilize in adsorption cooling systems, which desorption temperatures have to be lower than temperature of heat transport medium operation temperature. For verification of work of this system was constructed on the Department of power engineering on University of Zilina solar adsorption cooling device.

  14. Social marketing and the meaning of cool

    OpenAIRE

    Tapp, A.; Bird, S

    2008-01-01

    Commercial marketers have long understood the value of cool in designing and selling their products, and invest heavily in keeping in touch with the latest trends amongst their consumers. In this article, we contend that social marketers could use ‘cool’ to achieve goals of behavioural change, especially with teenagers. We trace the history of cool through to its current role in consumption, before exploring how commercial marketers keep track of cool trends. With a focus upon teenagers, typi...

  15. Thermotechnical performance of an air-cooled tuyere with air cooling channels in series

    Science.gov (United States)

    Shen, Yuansheng; Zhou, Yuanyuan; Zhu, Tao; Duan, Guangbin

    2017-01-01

    To reduce the cooling air consumption for an air-cooled tuyere, an air-cooled tuyere with air cooling channels in series is developed based on several hypotheses, i.e., a transparent medium in the blast furnace, among others, and the related mathematical models are introduced and developed. Referring to the data from a BF site, the thermotechnical computation for the air-cooled tuyere was performed, and the results show that when the temperature of the inlet cooling air increases, the temperatures for the outlet cooling air, the outer surface of the tuyere, the walls of the air cooling channels and the center channel as well as the heat going into the center channel increase, but the heat absorbed by the cooling air flowing through the air cooling channels decreases. When the cooling air flow rate under the standard state increases, the physical parameters mentioned above change in an opposite directions. Compared to a water-cooled tuyere, the energy savings for an air-cooled tuyere are more than 0.23 kg/min standard coal.

  16. 降温方法对不同成熟度鸭梨果肉脂氧合酶活性和膜脂脂肪酸的影响%Effect of different cooling methods on LOX activity and membrane fatty acid of different maturity Yali pear after harvest

    Institute of Scientific and Technical Information of China (English)

    梁丽雅; 胡小松; 何爱红; 汪政富; 闫师杰

    2012-01-01

    In order to investigate the mechanism that slow cooling inhibits browning of Yali after harvest,the effect of different cooling methods on membrane fatty acid components,contents,lipoxygenase(LOX) activity of flesh of Yali pear with different harvest period were studied.The results showed that LOX activity of Yali pear raised slowly and was higher in late harvest fruit during storage.Slow cooling inhibited LOX activity and browning of the flesh,it had obvious effect on early harvest fruit.Fatty acid components in flesh contained lauric acid,tetradecanoic acid,palmitic acid,palmitoleic acid,perlatolic acid,stearic acid,oleic acid,linoleic acid,linolenic acid.The content of linoleic acid,palmitic acid and oleic acid were higher than the other kinds of fatty acid.Late harvest and slow cooling obviously increased the U/S value in flesh of Yali.Slow cooling increased the content of linolenic acid and linoleic acid in flesh in early time during storage of Yali,and the content of linoleic acid and linolenic acid decreased along with the rise of LOX activity in the later period of storage,these two acids were possibly the reactive substrates of LOX.Early harvesting and slow cooling could increase the contents of unsaturated fatty acid and U/S value of flesh,restrain the flesh browning of Yali pear after harvest.%为了探讨缓慢降温抑制采后鸭梨果实褐变的机理,研究了不同降温方法对不同成熟度鸭梨果肉脂氧合酶(LOX)活性及膜脂脂肪酸组分和含量的影响。结果表明:在贮藏期间,LOX活性缓慢上升,晚采果活性较高;缓慢降温抑制了LOX活性的升高和果肉褐变,对早采果影响明显。鸭梨果肉中含有月桂酸、豆蔻酸、棕榈酸、棕榈油酸、珠光酸、硬脂酸、油酸、亚油酸、亚麻酸,其中含量较多的是亚油酸、棕榈酸和油酸。推迟采收和缓慢降温提高了果肉的U/S值,缓慢降温提高了鸭梨果肉的亚麻酸及前期的亚油酸含量,在贮藏

  17. Joint Cooling does not Hinder Athletic Performance during High-intensity Intermittent Exercise.

    Science.gov (United States)

    Kim, H; Lee, D; Choi, H-M; Park, J

    2016-07-01

    We examined the effects of ankle and knee joint cooling on 20-m sprint times and maximal vertical jump heights during high-intensity intermittent exercise. 21 healthy collegiate male basketball (n=14) and handball players (n=7) underwent 3 experimental sessions. Each session consisted of four 15-min quarters of high-intensity intermittent exercises including various intensities of 20-m shuttle running and jumping. A 20-min bilateral joint cooling (ankle, knee, or control-no cooling: in a counterbalanced order) was applied before quarters 1 and 3. After joint cooling, no warm-up activity other than the exercise protocol was given. The 20-m sprint times and maximal vertical jump heights in each experimental session were recorded at baseline (prior to quarter-1) and during each quarter. To test joint cooling effects over time, we performed 3×5 mixed model ANOVAs. Neither ankle nor knee joint cooling changed 20-m sprint times (F8,280=1.45; p=0.18) or maximal vertical jump heights (F8,280=0.76; p=0.64). However, a trend was observed in which joint cooling immediately decreased (quarters 1 and 3) but active warm-up for approximately 20 min improved 20-min sprint times (quarters 2 and 4). Our study suggests that athletic performance such as sprinting and jumping are not altered by joint cooling applied prior to or during high-intensity intermittent exercise.

  18. Sensor-Aided Localized Capsule-Cooling Using Neural Networks for Energy-Efficient Refrigeration

    Directory of Open Access Journals (Sweden)

    N. Banerjee

    2014-06-01

    Full Text Available Sensor-aided localized capsule-cooling technique is a unique refrigeration process where sensors precisely capsulate the location of an item(s on a shelf of a fridge and hence direct the governing artificial intelligence to take suitable action. Here the sensors are used to locate the objects and the designed smart system (neural network activates the corresponding ductlines to cool the object. Here neural network system opens the gate(s and tilts the angle to allow the flow of cool air through the ductlines. Then the orifices, which fall in the virtual “Hot Region”, the domain that the active sensors had created almost immediately on sensing an obstruction, are opened. The orifices and sensors are arranged in a series on the lower wall of the ductlines to allow flow of air in the downward direction. These open orifices facilitate the direct hitting of cool air on the target-item and hence create a cold block within a fridge, instead of cooling the entire fridge uniformly, to keep the singular item refrigerated. This mode of operation offering selective cooling, rather than the conventional uniform one, is useful in saving energy, as the region then needed to be cooled is reduced significantly. A detail structural and theoretical explanations along with graphical analysis clearly elucidate the effective working of this mechanism under practical circumstances is given here. In this paper neural network is used for capsule cooling for energy efficient refrigeration

  19. Solar air-conditioning-active, hybrid and passive

    Energy Technology Data Exchange (ETDEWEB)

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  20. Interferometric laser cooling of atomic rubidium

    CERN Document Server

    Dunning, Alexander; Bateman, James; Himsworth, Matthew; Freegarde, Tim

    2014-01-01

    We report the 1-D cooling of atoms using a velocity-dependent optical force based upon Ramsey matter-wave interferometry. The interferometer is realised with stimulated Raman transitions between ground hyperfine states, and after 12 cycles of the cooling sequence, we observe a reduction in the temperature of a freely moving cloud of magneto-optically cooled $^{85}$Rb atoms from 20 $\\mu$K to 4 $\\mu$K, accompanied in this first demonstration by an acceleration of the centre of mass of the atom cloud. This pulse-based laser cooling technique could in principle be extended to molecules and atoms that lack a closed radiative transition.