WorldWideScience

Sample records for bubble pump operated

  1. Microfluidic "blinking" bubble pump

    NARCIS (Netherlands)

    Yin, Zhizhong; Prosperetti, Andrea

    2005-01-01

    The paper reports data obtained on a simple micropump, suitable for electrolytes, based on the periodic growth and collapse of a single vapor bubble in a microchannel. With a channel diameter of the order of 100 µm, pumping rates of several tens of µl/min and pressure differences of several kPa are

  2. Liquid jet pumped by rising gas bubbles

    Science.gov (United States)

    Hussain, N. A.; Siegel, R.

    1975-01-01

    A two-phase mathematical model is proposed for calculating the induced turbulent vertical liquid flow. Bubbles provide a large buoyancy force and the associated drag on the liquid moves the liquid upward. The liquid pumped upward consists of the bubble wakes and the liquid brought into the jet region by turbulent entrainment. The expansion of the gas bubbles as they rise through the liquid is taken into account. The continuity and momentum equations are solved numerically for an axisymmetric air jet submerged in water. Water pumping rates are obtained as a function of air flow rate and depth of submergence. Comparisons are made with limited experimental information in the literature.

  3. Numerical Studies On Bubble Pump With Alternate Working Fluids

    Directory of Open Access Journals (Sweden)

    L. Bruno Augustin

    2013-10-01

    Full Text Available The importance of energy conservation in the context of growing global population and dwindling fossil fuel resources cannot be overemphasized. Energy can be conserved by using it more efficiently. The energy spent for an application should be of the correct amount and type. It would make more sense to spend heat energy for heating rather than the high grade electricity as most of the electric power in the world is generated from driving heat engines, for which heat is supplied from the combustion of fossil fuels. At the same time, depletion of these conventional resources also poses a serious problem in meeting energy requirements. In this paper, the bubble pump, which is an integral part of diffusion- absorption refrigeration system, has been investigated numerically .A thermally driven bubble pump, which can be powered by solar thermal energy, is used to lift the liquid. The bubble pump runs on solar energy and reduces the amount of energy spent by replacing the compressor in conventional vapour absorption refrigeration system. As a result of the absence of any mechanical moving part, the refrigerator is silent and very reliable in addition to an economical and environmental friendly device. The concept of such a pump is already in existence but optimization studies are yet to be extensively investigated. This paper deals with the comparison of various parameters of the bubble pump using water and Nonane as the working fluid. Numerical simulation of the bubble pump is carried out using simple numerical equations which assume slug flow in the bubble pump. The mass flow rate, the sensible heating time and position of heating element are varied and the effect it has on diameter of the pipe, pumping ratio and the heat required is studied for both the working fluids

  4. The Pumping Up Phenomenon of Double-Stage Bubble Pump with Water and Aqueous LiBr Solution

    Directory of Open Access Journals (Sweden)

    Hongtao Gao

    2013-02-01

    Full Text Available The double-stage bubble pump, using thermal energy as driving force to transport the solution, can replace the mechanical solution pump in the double-effect lithium bromide absorption chiller. By building a bench, a lot of experimental research and analysis were conducted with water and different concentrations of lithium bromide solution as the working fluid of the bubble pump. The first-stage bubble pump in the experiment pumps up by the external heat source. The heat for driving the second-stage bubble pump is provided by refrigerant steam produced from the first-stage bubble pump. The experiment data shows that the heating of refrigerant vapor is only one of the elements of pump-up phenomenon. Another is that the intermediate solution flashes to vapor to become bubbles. The pump-up phenomenon of double-stage bubble pump has much to do with the pressure difference of intermediate solution and first-stage refrigerant vapor. With water as the working fluid, when the pressure difference between refrigerant vapor and the intermediate liquefied refrigerant is 3.5-3.9 kPa, the bubble pump can pump up and run for some time and the start-up time decreases with the driving head. When the working fluid is lithium bromide solution, the pressure difference of the double-stage bubble pump increases with the solution concentration and is bigger than that of water. The start-up time increases with the concentrations of lithium bromide solution within the range of 45.5 to 54% and decreases within the range of 54-59.5%. The start-up time is largest at 54% under this experimental condition. The experimental result is also compared with the single-stage bubble pump. The start-up time of double-stage bubble pump decreases with the driving height, which is contrary to the single-stage bubble pump.

  5. Operating pumps on minimum flow

    Energy Technology Data Exchange (ETDEWEB)

    Casada, D.A. [Oak Ridge National Lab., TN (United States); Li, Y.C. [Nuclear Regulatory Commission, Washington, DC (United States)

    1992-06-01

    The Nuclear Regulatory Commission (NRC) staff issued Information Notice (IN) 87-59 to alert all licensees to two miniflow design concerns identified by Westinghouse. The first potential problem discussed in this IN involves parallel pump operation. If the head/capacity curve of one of the parallel pumps is greater than the other, the weaker pump may be dead-headed when the pumps are operating at low-flow conditions. The other problem related to potential pump damage as a result of hydraulic instability during low-flow operation. In NRC Bulletin 88-04, dated May 5, 1988, the staff requested all licensees to investigate and correct, as applicable, the two miniflow design concerns. The staff also developed a Temporary Instruction, Tl 2515/105, dated January 29, 1990 to inspect for the adequacy of licensee response and follow-up actions to NRC Bulletin 88-04. Oak Ridge National Laboratory has reviewed utility responses to Bulletin 88-04 under auspices of the NRC`s Nuclear Plant Aging Research Program, and participated in several NRC inspections. Examples of actions that have been taken, an assessment of the overall industry response, and resultant conclusions and recommendations are presented.

  6. Operating pumps on minimum flow

    Energy Technology Data Exchange (ETDEWEB)

    Casada, D.A. (Oak Ridge National Lab., TN (United States)); Li, Y.C. (Nuclear Regulatory Commission, Washington, DC (United States))

    1992-01-01

    The Nuclear Regulatory Commission (NRC) staff issued Information Notice (IN) 87-59 to alert all licensees to two miniflow design concerns identified by Westinghouse. The first potential problem discussed in this IN involves parallel pump operation. If the head/capacity curve of one of the parallel pumps is greater than the other, the weaker pump may be dead-headed when the pumps are operating at low-flow conditions. The other problem related to potential pump damage as a result of hydraulic instability during low-flow operation. In NRC Bulletin 88-04, dated May 5, 1988, the staff requested all licensees to investigate and correct, as applicable, the two miniflow design concerns. The staff also developed a Temporary Instruction, Tl 2515/105, dated January 29, 1990 to inspect for the adequacy of licensee response and follow-up actions to NRC Bulletin 88-04. Oak Ridge National Laboratory has reviewed utility responses to Bulletin 88-04 under auspices of the NRC's Nuclear Plant Aging Research Program, and participated in several NRC inspections. Examples of actions that have been taken, an assessment of the overall industry response, and resultant conclusions and recommendations are presented.

  7. Optimization of the Geometrical Parameters of a Solar Bubble Pump for Absorption-Diffusion Cooling Systems

    Directory of Open Access Journals (Sweden)

    N. Dammak

    2010-01-01

    Full Text Available Problem statement: The objective of this study was to optimize the geometrical parameters of a bubble pump integrated in a solar flat plate collector. Approach: This solar bubble pump was part of an ammonia/water/helium (NH3/H2O/He absorption-diffusion cooling system. Results: An empirical model was developed on the basis of momentum, mass, material equations and energy balances. The mathematical model was solved using the simulation tool “Engineering Equation Solver (EES”. Conclusion/Recommendations: Using metrological data from Gabes (Tunisia various parameters were geometrically optimized for maximum bubble pump efficiency which was best for a bubble pump tube diameter of 6 mm, a tube length of 1.5 m, an inclination to the horizontal between 30 and 50° of the solar flat plate collector and a submergence ratio between 0.2 and 0.3.

  8. Development of a capillary plasma pump with vapour bubble for water purification: experimental and theoretical investigation

    Science.gov (United States)

    Uehara, S.; Ishihata, K.; Nishiyama, H.

    2016-10-01

    This paper describes the development of a small-sized reactive plasma pump driven by capillary bubble discharge for the purification of treated water. The apparatus we developed decomposes the pollutants in the water by using chemical species generated by the plasma discharge. The resulting stream of bubbles obviates the need for an external gas supply or pump to transport the water. A high-speed camera was used to investigate the bubble dynamics responsible for the pumping effect, which is achieved by selecting the shape of the capillary such that the bubble ejections within enhance the ‘self-repetition’ action required for the pumping motion. Our experiments showed that optimal bubble generation requires a consumed power of 17.8 W. A theoretical model was developed to investigate the pumping mechanism. We solve the problems associated with liquid oscillations in the U-shaped water reservoir by employing a non-uniform cross-sectional area in our model. The chemical reactivity of the device was confirmed by using emission spectroscopy of OH radical and by measuring the decomposition of methylene blue.

  9. Numerical simulation of a thermal-bubble actuated diffuser-nozzle valveless pump

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A valveless micropump actuated by thermal bubbles which are generated by an electrode heater mounted with a pair of diffuser nozzles has been numerically studied by commercial CFD software FLUENT. The relationships between the net flow rate and the superheating and heat supplying frequency have been investigated. The depth of the diffuser-nozzle micropump is 200 μm, the diameter of the actuating chamber is 1 mm, and a pair of diffuser nozzles whose gap has been expanded from 30 μm to 274 μm with an open angle of 7° are connected to the actuating chamber. The working fluid is methanol. In the numerical simulation, the flow pattern is laminar. The results show that the pump has different optimal driving frequencies at different superheating. A cycle resulting from bubble growth and shrinking costs more time at higher superheating temperature; different superheating has different optimal driving frequency; when the superheating increases, the maximum volume flow rate and the maximum pump pressure will increase simultaneously, and the optimal driving frequency decreases as well, the maximum volume flow rate and pump pressure also have the same tendency; in the condition of uncontrolled condensing, the bubble shrinking process is longer than the growth process, thus it is the determining factor to affect the pump performance. The maximum volume flow rate is 9.02 μL/min at △T = 15℃, and the maximum pump pressure is 680 Pa. With the increase of wall superheat, cycle including the bubble growth and condensation will become longer, resulting in a significant impact on the pumping flow; different wall superheat has different optimized frequency, increasing superheat will bring increased pumping flow and pump pressure, the optimized driving frequency will be reduced; liquid supply phase is longer than pumping phase.

  10. Performance monitoring of a bubble pumped solar domestic hot water system - final report

    Energy Technology Data Exchange (ETDEWEB)

    Makuch, P.D.; Harrison, S.J. [Queen`s Univ., Kingston, ON (Canada). Solar Calorimetry Lab.

    1995-12-01

    A new type of solar domestic hot water (SDHW) system for cold climates was described. The bubble pump system is self pumping and self regulating (it circulates anti-freeze). The system transports heat from roof mounted solar collectors to a thermal storage located at a lower level when there is available solar radiation. The design is unique in that it has no moving parts and requires no external electrical or mechanical input to operate. A unit was installed on a row house in Kingston, Ontario, to evaluate its performance. The average daily solar fraction was 32.4 per cent, and the average system efficiency for the monitored period was 13.4 per cent. This was below expectations due to low hot water demand. Performance improved somewhat towards the end of the monitoring period due to increased demand for hot water, improvements to the system, and increased solar insulation. A more realistic annual performance was estimated at 19 per cent for system efficiency and 41 per cent for solar fraction. Further improvements could be expected, especially in mid-winter performance, if the solar collector slope could be increased to a value of 45 to 60 degrees to the horizontal. 8 refs., 14 tabs., 9 figs.

  11. Structure and operation of bacterial tripartite pumps.

    Science.gov (United States)

    Hinchliffe, Philip; Symmons, Martyn F; Hughes, Colin; Koronakis, Vassilis

    2013-01-01

    In bacteria such as Pseudomonas aeruginosa and Escherichia coli, tripartite membrane machineries, or pumps, determine the efflux of small noxious molecules, such as detergents, heavy metals, and antibiotics, and the export of large proteins including toxins. They are therefore influential in bacterial survival, particularly during infections caused by multidrug-resistant pathogens. In these tripartite pumps an inner membrane transporter, typically an ATPase or proton antiporter, binds and translocates export or efflux substrates. In cooperation with a periplasmic adaptor protein it recruits and opens a TolC family cell exit duct, which is anchored in the outer membrane and projects across the periplasmic space between inner and outer membranes. Assembled tripartite pumps thus span the entire bacterial cell envelope. We review the atomic structures of each of the three pump components and discuss how these have allowed high-resolution views of tripartite pump assembly, operation, and possible inhibition.

  12. Bubbles

    DEFF Research Database (Denmark)

    Dholakia, Nikhilesh; Turcan, Romeo V.

    2013-01-01

    A goal of our ongoing research stream is to develop a multidisciplinary metatheory of bubbles. In this viewpoint paper we put forward a typology of bubbles by comparing four types of assets – entertainment, commodities, financial securities (stocks), and housing properties – where bubbles could a...

  13. Manually operated elastomer heat pump

    Science.gov (United States)

    Hutchinson, W. D.

    1970-01-01

    Device consisting of a rotating mechanism, a frame with multiple wide bands of rubber, and a fluid bath, demonstrates the feasibility of a human operated device capable of cooling or producing heat. This invention utilizes the basic thermodynamic properties of natural rubber.

  14. 3-dimensional Simulation of an Air-lift Pump from Bubbly to Slug Flow

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Hongrae; Jo, Daeseong [Kyungpook National Univ, Daegu (Korea, Republic of)

    2015-10-15

    The air-lift pump has been used in various applications with its merit that it can pump up without any moving parts. E.g. coffee percolator, petroleum industry, suction dredge, OTEC i.e. ocean thermal energy conversion and so on. By the merit, it has high durability for high temperature water or vapor, and fluid-solid mixture like waste water, muddy water and crude, which cause problems when it's pumped up with general pumps. In this regard, the air-lift pump has been one of the most desirable technology. A typical air-lift pump configuration is illustrated in Figure 01. The principle of this pump is very simple. When air is injected from the injector at bottom of a submerged tube, i.e., air bubbles are suspended in the liquid, the average density of the mixture in the tube is less than that of the surrounding fluid in the reservoir. Then hydrostatic pressure over the length of the tube is decreased. This buoyancy force causes a pumping action. The comparison of the simulated results, experimental result, and theoretical result is been able by data shown as Figure 04. They have similar trends but they also have a little differences because there are some limits of simulating the flow regimes. At the different flow condition, different coefficients for friction factor or pressure drop should be used, but this simulation uses a laminar condition and the theoretical equations are valid only for slug regime where the air flow rate is lower than the other regimes. From these causes, the differences has arisen, and difference comes bigger as the air flow rate increases, i.e., becoming annular flow regime or churn flow regime.

  15. Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Tao Li

    2013-01-01

    Full Text Available A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Results show that the system flow rate is determined by the sliding vane pump. In order to ensure the stability of the series operation pumping system, the energy consumption required by the pipeline under the system flow should be greater than the pressure energy centrifugal pump can generate. Otherwise, the centrifugal pump can not operate stably, with reflux, swirl, gas-liquid two-phase flow in the runner and strong vibration and noise. The sliding vane pump can be in serial operation with the centrifugal pump under limited conditions.

  16. Damages on pumps and systems the handbook for the operation of centrifugal pumps

    CERN Document Server

    Merkle, Thomas

    2014-01-01

    Damage on Pumps and Systems. The Handbook for the Operation of Centrifugal Pumps offers a combination of the theoretical basics and practical experience for the operation of circulation pumps in the engineering industry. Centrifugal pumps and systems are extremely vulnerable to damage from a variety of causes, but the resulting breakdown can be prevented by ensuring that these pumps and systems are operated properly. This book provides a total overview of operating centrifugal pumps, including condition monitoring, preventive maintenance, life cycle costs, energy savings and economic aspects. Extra emphasis is given to the potential damage to these pumps and systems, and what can be done to prevent breakdown. Addresses specific issues about pumping of metal chips, sand, abrasive dust and other solids in fluidsEmphasis on economic and efficiency aspects of predictive maintenance and condition monitoring Uses life cycle costs (LCC) to evaluate and calculate the costs of pumping systems

  17. Estimation of pump operational state with model-based methods

    Energy Technology Data Exchange (ETDEWEB)

    Ahonen, Tero; Tamminen, Jussi; Ahola, Jero; Viholainen, Juha; Aranto, Niina [Institute of Energy Technology, Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta (Finland); Kestilae, Juha [ABB Drives, P.O. Box 184, FI-00381 Helsinki (Finland)

    2010-06-15

    Pumps are widely used in industry, and they account for 20% of the industrial electricity consumption. Since the speed variation is often the most energy-efficient method to control the head and flow rate of a centrifugal pump, frequency converters are used with induction motor-driven pumps. Although a frequency converter can estimate the operational state of an induction motor without external measurements, the state of a centrifugal pump or other load machine is not typically considered. The pump is, however, usually controlled on the basis of the required flow rate or output pressure. As the pump operational state can be estimated with a general model having adjustable parameters, external flow rate or pressure measurements are not necessary to determine the pump flow rate or output pressure. Hence, external measurements could be replaced with an adjustable model for the pump that uses estimates of the motor operational state. Besides control purposes, modelling the pump operation can provide useful information for energy auditing and optimization purposes. In this paper, two model-based methods for pump operation estimation are presented. Factors affecting the accuracy of the estimation methods are analyzed. The applicability of the methods is verified by laboratory measurements and tests in two pilot installations. Test results indicate that the estimation methods can be applied to the analysis and control of pump operation. The accuracy of the methods is sufficient for auditing purposes, and the methods can inform the user if the pump is driven inefficiently. (author)

  18. The cultivation of Anabaena variabilis in a bubble column operating under bubbly and slug flows.

    Science.gov (United States)

    Yoon, Jong Hyun; Choi, Shin Sik; Park, Tai Hyun

    2012-04-01

    In a bubble column reactor with an inner diameter of 6cm and a height of 63cm for the culture of cyanobacteria two different shapes of bubbles can be generated, resulting in bubbly flow or slug flow. Growth of Anabaena variabilis under slug flow (1.9g/l/day) was 1.73 times higher than that under bubbly flow (1.1g/l/day) when the specific irradiation rate was maintained above 10μmol/s/g dry cell. Although a stepwise increase in superficial gas velocity enhanced the average cell growth rate under bubbly flow by 1.57 times, the average cell growth rate during the deceleration phase under bubbly flow (1.98g/l/day) was 0.61 times smaller than that under slug flow (3.22g/l/day). These results demonstrate that the bubble shape in the slug flow was advantageous in regards to the radial circulation of cells.

  19. A technique for automatic tubing occlusion in response to air bubble detection when using a centrifugal pump.

    Science.gov (United States)

    Paulsen, A W; Hargadine, W L; Lambert, G S; Long, A C

    1990-01-01

    A double acting pneumatically powered cylinder, energized by an electrically activated solenoid valve, is used to occlude the outflow line from a Bio-Medicus (a) constrained vortex pump. The cylinder is mounted on a tubing guide that is fastened to a pole clamp. A Sarns (b) air bubble detector, placed on the pump inflow line is used to provide the signal to activate the solenoid valve. The outflow occluder is capable of 100% occlusion of 3/8 x 3/32 inch Tygon tubing up to pressures of 2586 mmHg. The occluder system is able to work with many types of bubble detectors and is applicable to any form of non-occlusive pump.

  20. Operating characteristics of isocaloric fountain-effect pumps

    Science.gov (United States)

    Kittel, Peter

    1988-01-01

    The governing equations of thermomechanical (fountain-effect) pumps are usually given for pumps operating at a constant temperature difference. These are the thermomechanical and mechanocaloric effects in which the pressure head and mass flow are independent of each other. Here, these equations are recast for a pump operating at a constant heat input (isocaloric). This form more closely represents how such pumps are likely to be used. Under these conditions, the pressure head and mass flow are shown to be related. For ideal pumps, the head and flow are related by a universal curve. For real pumps (those that have normal fluid leakage), a family of curves is developed. These curves approach the curve for an ideal pump at high flow rates. The isocaloric equations are also extended to multistage pumps.

  1. Nuclear Waste Cross Site Transfer Pump Operational Resonance Resolution

    Energy Technology Data Exchange (ETDEWEB)

    HAUCK, F.M.

    1999-12-01

    Two single-volute, multi-stage centrifugal pumps are installed at a nuclear waste transfer station operated by the Department of Energy in Hanford, WA. The two parallel 100% pumps are Variable Frequency Drive operated and designed to transport waste etc.

  2. Analysis of Variable Speed Optimization Operation Effect of Different-type Pumps in Jiangdu Pumping Station

    Science.gov (United States)

    Jinxian, Qiu; Jilin, Cheng; Jinyao, Luo; Rentian, Zhang; Lihua, Zhang; Yi, Gong

    2010-06-01

    The following paper puts forward 45 combination schemes of different-type pumps in different daily-average heads and operation loads in Jiangdu Pumping Station. Based on every scheme, the minimum electricity consumption cost selected as the objective function, this paper gives the results of variable speed optimal operations with dynamic planning methods in both considering time-sharing electricity prices and not, simultaneously, it gives the results of fixed speed conventional operation considering time-sharing electricity prices. Then according to the unit energy consumption cost, the paper gives comparison analysis of the effect of different-type pumps in variable speed optimization operation, the conclusions can offer decision-making bases for optimization research of pumping stations considering time-sharing electricity prices and tide levels of Yangtze River, and offer references for transformation and economical operation of large and medium-size pumping stations.

  3. Operational Safety Analysis of CEFR Main Feed Pump

    Institute of Scientific and Technical Information of China (English)

    DING; Tong-wei; ZHANG; Huan-qi

    2012-01-01

    <正>China Experimental Fast Reactor (CEFR) use three main feed pumps, two parallel running and one standby at full power. During CEFR operation, the pressure of deaerator is maintained at (1.16±0.01) MPa. Combined with the actual condition of the single feed pump carried out the NPSH analysis of full flow range calculation, the results are listed in Table 1. The actual measured mounting height of feed water pump is -19.2 m. The analysis results that the main feed pumps running condition cavitation does not

  4. Elements for Effective Management of Operating Pump and Treat Systems

    Science.gov (United States)

    This fact sheet summarizes key aspects of effective management for operating pump and treat (P&T) systems based on lessons learned from conducting optimization evaluations at 20 Superfund-financed P&T systems.

  5. Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Josh A. Salmond

    2009-08-07

    The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and low residual stresses. The products fabricated are used on multiple programs.

  6. Is mudflow in Sidoarjo, East Java due to the pumping mechanism of hot air bubbles? : Laboratory simulations and field observations

    Science.gov (United States)

    Nurhandoko, Bagus Endar B.

    2015-09-01

    Extraordinary mudflow has happened in Sidoarjo, East Java, Indonesia since 2006. This mud comes from the giant crater that is located close to the BJP - 01. Thousands of homes have been submerged due to mudflow. Till today this giant mud crater is still has great strength despite the mud flowing over 8 years. This is a very rare phenomenon in the world. This mud flow mechanism raises big questions, because it has been going on for years, naturally the mudflow will stop by itself because the pressure should be reduced. This research evaluates all aspects of integrated observations, laboratory tests and field observations since the beginning of this ongoing mudflow. Laboratory tests were done by providing hot air bubbles into the fluid inside the inverted funnel showed that the fluid can flow with a high altitude. It is due to the mechanism of buoyant force from air bubbles to the water where the contrast density of the water and the air is quite large. Quantity of air bubbles provides direct effect to the debit of fluid flow. Direct observation in the field, in 2006 and 2007, with TIMNAS and LPPM ITB showed the large number of air bubbles on the surface of the mud craters. Temperature observation on the surface of mud crater is around 98 degree C whereas at greater depth shows the temperature is increasingly rising. This strengthens the hypothesis or proves that the mud pumping mechanism comes from buoyant force of hot air bubbles. Inversion gravity images show that the deep subsurface of main crater is close to volcanic layers or root of Arjuna mountain. Based on the simulation laboratory and field observation data, it can be concluded that the geothermal factor plays a key role in the mudflow mechanism.

  7. Convection pump and method of operation

    Energy Technology Data Exchange (ETDEWEB)

    Steinhour, Leif Alexi

    2017-07-11

    This disclosure provides systems, methods, and apparatus related to a convection pump. In one aspect, an apparatus includes a chamber, the chamber having an inlet at a first end of the chamber and an outlet at a second end of the chamber. The chamber further has a first surface and a second surface, the first surface being opposite to the second surface. A baffle having a substantially helical shape is disposed inside the chamber. A heating device is configured to heat the first surface of the chamber. A cooling device is configured to cool the second surface of the chamber.

  8. Efficient potassium diode pumped alkali laser operating in pulsed mode.

    Science.gov (United States)

    Zhdanov, Boris V; Rotondaro, Matthew D; Shaffer, Michael K; Knize, Randall J

    2014-07-14

    This paper presents the results of our experiments on the development of an efficient hydrocarbon free diode pumped alkali laser based on potassium vapor buffered by He gas at 600 Torr. A slope efficiency of more than 50% was demonstrated with a total optical conversion efficiency of 30%. This result was achieved by using a narrowband diode laser stack as the pump source. The stack was operated in pulsed mode to avoid limiting thermal effects and ionization.

  9. High-speed flow visualization in a pump-turbine under off-design operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hasmatuchi, V; Roth, S; Botero, F; Avellan, F; Farhat, M, E-mail: vlad.hasmatuchi@epfl.c [Laboratory for Hydraulic Machines, Ecole Polytechnique Federale de Lausanne Av. de Cour 33bis, Lausanne, CH-1007 (Switzerland)

    2010-08-15

    The flow hydrodynamics in a low specific speed radial pump-turbine reduced scale model is experimentally investigated under off-design operating conditions in generating mode. Wall pressure measurements, in the stator, synchronized with high-speed flow visualizations in the vaneless space between the impeller and the guide vanes using air bubbles injection are performed. When starting from the best efficiency point and increasing the runner speed, a significant increase of the pressure fluctuations is observed mainly in channels between wicket gates. The spectral analysis shows a rise of one stall cell, rotating with about 70% of the impeller frequency, at runaway, which further increases as the zero discharge condition is approached. Then a specific image processing technique is detailed and applied to create a synthetic instantaneous view of the flow pattern on the entire guide vanes circumference for an operating point in turbine-brake mode, where backflow and vortices accompany the stall passage.

  10. Vapor-Compression Heat Pumps for Operation Aboard Spacecraft

    Science.gov (United States)

    Ruemmele, Warren; Ungar, Eugene; Cornwell, John

    2006-01-01

    Vapor-compression heat pumps (including both refrigerators and heat pumps) of a proposed type would be capable of operating in microgravity and would be safe to use in enclosed environments like those of spacecraft. The designs of these pumps would incorporate modifications of, and additions to, vapor-compression cycles of heat pumps now used in normal Earth gravitation, in order to ensure efficiency and reliability during all phases of operation, including startup, shutdown, nominal continuous operation, and peak operation. Features of such a design might include any or all of the following: (1) Configuring the compressor, condenser, evaporator, valves, capillary tubes (if any), and controls to function in microgravitation; (2) Selection of a working fluid that satisfies thermodynamic requirements and is safe to use in a closed crew compartment; (3) Incorporation of a solenoid valve and/or a check valve to prevent influx of liquid to the compressor upon startup (such influx could damage the compressor); (4) Use of a diode heat pipe between the cold volume and the evaporator to limit the influx of liquid to the compressor upon startup; and (5) Use of a heated block to vaporize any liquid that arrives at the compressor inlet.

  11. 980nm diode laser pump modules operating at high temperature

    Science.gov (United States)

    Campbell, Jenna; Semenic, Tadej; Leisher, Paul; Bhunia, Avijit; Mashanovitch, Milan; Renner, Daniel

    2016-03-01

    Existing thermal management technologies for diode laser pumps place a significant load on the size, weight and power consumption of High Power Solid State and Fiber Laser systems, thus making current laser systems very large, heavy, and inefficient in many important practical applications. This problem is being addressed by the team formed by Freedom Photonics and Teledyne Scientific through the development of novel high power laser chip array architectures that can operate with high efficiency when cooled with coolants at temperatures higher than 50 degrees Celsius and also the development of an advanced thermal management system for efficient heat extraction from the laser chip array. This paper will present experimental results for the optical, electrical and thermal characteristics of 980 nm diode laser pump modules operating effectively with liquid coolant at temperatures above 50 degrees Celsius, showing a very small change in performance as the operating temperature increases from 20 to 50 degrees Celsius. These pump modules can achieve output power of many Watts per array lasing element with an operating Wall-Plug-Efficiency (WPE) of >55% at elevated coolant temperatures. The paper will also discuss the technical approach that has enabled this high level of pump module performance and opportunities for further improvement.

  12. PUMPS

    Science.gov (United States)

    Thornton, J.D.

    1959-03-24

    A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.

  13. Approaches to Stable Operation of Shaftless Centrifugal Pump

    Institute of Scientific and Technical Information of China (English)

    Ryunosuke Kawashima; Mitsuo Uno; Toshiaki Kanemoto

    2009-01-01

    The shaft-less impeller of the centrifugal pump, which is driven by the magnetic induction, was developed. The impeller rotates under the floating condition without any control device. The floating condition of the impeller is realized by utilizing the pressure in pump casing. The pump performance and the rotational behavior of the im-peUer were investigated experimentally. It has found that the floating position of the impeller become quite unsta-ble in a partial flow rate operation. And the pressure distribution at the casing wall affects the rotational posture of the impeller. This paper presents the effect of the casing treatment on the rotational posture of the impeller and the pressure distribution. The reasonable casing treatment is available for the stable rotational posture of the impeller.

  14. Approaches to stable operation of shaftless centrifugal pump

    Science.gov (United States)

    Kawashima, Ryunosuke; Uno, Mitsuo; Kanemoto, Toshiaki

    2009-03-01

    The shaft-less impeller of the centrifugal pump, which is driven by the magnetic induction, was developed. The impeller rotates under the floating condition without any control device. The floating condition of the impeller is realized by utilizing the pressure in pump casing. The pump performance and the rotational behavior of the impeller were investigated experimentally. It has found that the floating position of the impeller become quite unstable in a partial flow rate operation. And the pressure distribution at the casing wall affects the rotational posture of the impeller. This paper presents the effect of the casing treatment on the rotational posture of the impeller and the pressure distribution. The reasonable casing treatment is available for the stable rotational posture of the impeller.

  15. A remotely operated drug delivery system with an electrolytic pump and a thermo-responsive valve

    KAUST Repository

    Yi, Ying

    2015-07-22

    Implantable drug delivery devices are becoming attractive due to their abilities of targeted and controlled dose release. Currently, two important issues are functional lifetime and non-controlled drug diffusion. In this work, we present a drug delivery device combining an electrolytic pump and a thermo-responsive valve, which are both remotely controlled by an electromagnetic field (40.5 mT and 450 kHz). Our proposed device exhibits a novel operation mechanism for long-term therapeutic treatments using a solid drug in reservoir approach. Our device also prevents undesired drug liquid diffusions. When the electromagnetic field is on, the electrolysis-induced bubble drives the drug liquid towards the Poly (N-Isopropylacrylamide) (PNIPAM) valve that consists of PNIPAM and iron micro-particles. The heat generated by the iron micro-particles causes the PNIPAM to shrink, resulting in an open valve. When the electromagnetic field is turned off, the PNIPAM starts to swell. In the meantime, the bubbles are catalytically recombined into water, reducing the pressure inside the pumping chamber, which leads to the refilling of the fresh liquid from outside the device. A catalytic reformer is included, allowing more liquid refilling during the limited valve\\'s closing time. The amount of body liquid that refills the drug reservoir can further dissolve the solid drug, forming a reproducible drug solution for the next dose. By repeatedly turning on and off the electromagnetic field, the drug dose can be cyclically released, and the exit port of the device is effectively controlled.

  16. The operation of a track sensitive hydrogen target in a 500 l neon hydrogen bubble chamber

    CERN Document Server

    Ayres, J F; Damerell, A R; Fisher, Colin M; Fitzharris, E W; Foster, J H; Gottfeldt, P; Mack, B; Mortimer, A R; Seager, P; Stokoe, J R; Williams, P R; Leutz, H; Tischhauser, Johann; Wenninger, Horst

    1973-01-01

    A 20 l hydrogen filled track sensitive target has been successfully operated in the 1.5 m cryogenic bubble chamber at The Rutherford High Energy Laboratory. The chamber is filled with a mixture of neon and hydrogen at a concentration of 45 mol eon giving a radiation length of 860 mm. Satisfactory track quality in both target and chamber is achieved and 65000 pictures have been obtained in a 4 GeV/c pi /sup +/ beam. (7 refs).

  17. The Operational Features of Pumping Stations Equiped with Parallel-Connected Centrifugal Pumps for Land-Reclamation

    Directory of Open Access Journals (Sweden)

    Khalid S. Al-Rababa

    2005-01-01

    Full Text Available The required water supply of a pump could be provided by means of different combinations of pressure piping and pumping units at different operational costs. The basic indices describing the operational modes for the individual and group pumping units, including the values of the efficiency, are computed. The adequacy of the calculational results that based on the developed mathematical models is confirmed by the full-scale experimental researches. Based on the presented principles of the load distribution between parallel working pumping units, 5 % of consumed electric power may be saved.

  18. Modeling Optimal Scheduling for Pumping System to Minimize Operation Cost and Enhance Operation Reliability

    Directory of Open Access Journals (Sweden)

    Yin Luo

    2012-01-01

    Full Text Available Traditional pump scheduling models neglect the operation reliability which directly relates with the unscheduled maintenance cost and the wear cost during the operation. Just for this, based on the assumption that the vibration directly relates with the operation reliability and the degree of wear, it could express the operation reliability as the normalization of the vibration level. The characteristic of the vibration with the operation point was studied, it could be concluded that idealized flow versus vibration plot should be a distinct bathtub shape. There is a narrow sweet spot (80 to 100 percent BEP to obtain low vibration levels in this shape, and the vibration also follows similar law with the square of the rotation speed without resonance phenomena. Then, the operation reliability could be modeled as the function of the capacity and rotation speed of the pump and add this function to the traditional model to form the new. And contrast with the tradition method, the result shown that the new model could fix the result produced by the traditional, make the pump operate in low vibration, then the operation reliability could increase and the maintenance cost could decrease.

  19. Pump/Control System Minimum Operating Cost Testing

    Science.gov (United States)

    1977-01-01

    A preliminary evaluation of pump performance was initiated to determine the efficiencies of an arbitrary group of small pumps. Trends in factors affecting energy usage in typical prime movers which might be used in liquid transport solar systems were assessed. Comparisons of centrifugal pump efficiencies were made from one manufacturer to another. Tests were also made on two positive-displacement pumps and comparisons with centrifugal pumps were observed.

  20. Heat pumps: planning, optimisation, operation and maintenance; Waermepumpen. Planung - Optimierung - Betrieb - Wartung

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, P. [Kunz-Beratungen, Dietlikon (Switzerland); Afjei, T. [Fachhochschule Nordwestschweiz, Institut fuer Energie am Bau, Muttenz (Switzerland); Betschart, W.; Prochaska, V. [Hochschule Luzern, Technik und Architektur, Horw (Switzerland); Hubacher, P. [Hubacher Engineering, Engelburg (Switzerland); Loehrer, R. [Scheco AG, Winterthur (Switzerland); Mueller, A. [Mueller und Pletscher AG, Winterthur (Switzerland)

    2008-01-15

    This handbook issued by the Swiss Federal Office of Energy (SFOE) in co-operation with a trade publication takes a look at the planning, optimisation, operation and maintenance of heat pumps. First of all, the basics of heat pump technology, heat pump components and refrigerants are discussed. Then, heat sources and heat distribution are looked at, followed by chapters on the integration of heat pumps into heating systems and noise protection topics. The definition of projects, commissioning and operation of heat pump systems are then discussed. Examples of installations round off the handbook.

  1. Experimental and theoretical study on cavitation inception and bubbly flow dynamics. Part 1: Design, development and operation of a cavitation susceptibility meter. Part 2: Linearized dynamics of bubbly and cavitating flows with bubble dynamics effects

    Science.gov (United States)

    Dagostino, Luca

    1987-05-01

    This theses presents the design, development and operations of a Cavitation Susceptibility Meter based on the use of a venturi tube for the measurement of the content of active cavitation nuclei in water samples. The pressure at the venturi throat is determined from the upstream pressure and the local flow velocity without corrections for viscous effects because the flow possesses a laminar potential core in all operational conditions. The detection ov cavitation and the measurement of the flow velocity are carried out optically. The apparatus comprises a Laser Doppler Velocimeter for the measurement of the flow velocity and the detection of cavitation, a custom-made electronic Signal Processor for real time generation and temporary storage of the data and a computerized system for the final acquisition and reduction of the collected data. The results of application of the Cavitation Susceptibility Meter to the measurement of the water quality of the tap water samples are presented. The results of an investigation are presented on the linearized dynamics of two-phase bubbly flows with the inclusion of bubble dynamics effects. Two flow configurations have been studied: the time dependent one-dimensional flow of a spherical bubble cloud subject to harmonic excitation of the far field external pressure and the steady state two-dimensional flow of a bubbly mixture on a slender profile of arbitrary shape.

  2. A study on diagnostic techniques of pump operating condition

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Du Eon; Park, Jong Ho; Song, Gyu Jo; Shin, Pil Kwon; Lee, Nam Gil; Shin, Wan Sun; Kang, Hyeon Taek; Lee, Taek Sang [Chungnam National Univ., Taejon (Korea, Republic of)

    1998-03-15

    The scope and contents investigate and reviewed are as follows : establishment of study plan and references survey, review of related problems and inservice test standards of safety injection pump in use nuclear power plant, review of the study results in laboratory, the theoretical investigation of temperature rise according to mini-flow rate of pump, mini-flow rate working characteristics of high and low pressure injection pumps at nuclear power plants, setup of testing equipment for measuring ampere, discharge pressure and vibration, selection and behaviors analysis of major parameters concerning pump degradation.

  3. Single-frequency operation of a diode-pumped green laser using multi-Brewster plates

    Institute of Scientific and Technical Information of China (English)

    Quan Zheng(郑权); Ling Zhao(赵岭); Longsheng Qian(钱龙生)

    2003-01-01

    In a diode-pumped, KTP intracavity frequency-doubled green laser, multi-Brewster plates are used toachieve high power single-frequency operation. With a simple experimental setup, single-frequency opera-tion of the diode-pumped green laser with output of 46 and 218 mW is obtained by one and three Brewsterplate, respectively.

  4. Leaky valves: new operation improves the heart's pumping action

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The action of any pump will start to decline when the valves no longer close properly. The same goes for the heart, the pump that maintains the circulation in our vascular system. Consequently, a major field of focus of open heart surgery is the repair or replacement of heart valves. Petr Havl a Ph.

  5. Fluid dynamic characterization of operating conditions for continuous flow blood pumps.

    Science.gov (United States)

    Wu, Z J; Antaki, J F; Burgreen, G W; Butler, K C; Thomas, D C; Griffith, B P

    1999-01-01

    As continuous flow pumps become more prominent as long-term ventricular assist devices, the wide range of conditions under which they must be operated has become evident. Designed to operate at a single, best-efficiency, operating point, continuous flow pumps are required to perform at off-design conditions quite frequently. The present study investigated the internal fluid dynamics within two representative rotary fluid pumps to characterize the quality of the flow field over a full range of operating conditions. A Nimbus/UoP axial flow blood pump and a small centrifugal pump were used as the study models. Full field visualization of flow features in the two pumps was conducted using a laser based fluorescent particle imaging technique. Experiments were performed under steady flow conditions. Flow patterns at inlet and outlet sections were visualized over a series of operating points. Flow features specific to each pump design were observed to exist under all operating conditions. At off-design conditions, an annular region of reverse flow was commonly observed within the inlet of the axial pump, while a small annulus of backflow in the inlet duct and a strong disturbed flow at the outlet tongue were observed for the centrifugal pump. These observations were correlated to a critical nondimensional flow coefficient. The creation of a "map" of flow behavior provides an additional, important criterion for determining favorable operating speed for rotary blood pumps. Many unfavorable flow features may be avoided by maintaining the flow coefficient above a characteristic critical coefficient for a particular pump, whereas the intrinsic deleterious flow features can only be minimized by design improvement. Broadening the operating range by raising the band between the critical flow coefficient and the designed flow coefficient, is also a worthy goal for design improvement.

  6. A self-priming, roller-free, miniature, peristaltic pump operable with a single, reciprocating actuator

    Science.gov (United States)

    Shkolnikov, Viktor; Ramunas, John; Santiago, Juan G.

    2013-01-01

    We present a design for a miniature self-priming peristaltic pump actuated with a single linear actuator, and which can be manufactured using conventional materials and methods. The pump is tolerant of bubbles and particles and can pump liquids, foams, and gases. We explore designs actuated by a motor (in depth) and a shape memory alloy (briefly); and briefly present a manually actuated version. The pump consists of a Delrin acetal plastic body with two integrated valves, a flexible silicone tube, and an actuator. Pumping is achieved as the forward motion of the actuator first closes the upstream valve, and then compresses a section of the tube. The increased internal pressure opens a downstream burst valve to expel the fluid. Reduced pressure in the pump tube allows the downstream valve to close, and removal of actuator force allows the upstream valve and pump tube to open, refilling the pump. The motor actuated design offers a linear dependence of flow rate on voltage in the range of 1.75–3 V. Flow rate decreases from 780 μl/min with increasing back pressure up to the maximum back pressure of 48 kPa. At 3 V and minimum back pressure, the pump consumes 90 mW. The shape memory alloy actuated design offers a 5-fold size and 4-fold weight reduction over the motor design, higher maximum back pressure, and substantial insensitivity of flow rate to back pressure at the cost of lower power efficiency and flow rate. The manually actuated version is simpler and appropriate for applications unconstrained by actuation distance. PMID:24672145

  7. First Dark Matter Search Results from a 4-kg CF$_3$I Bubble Chamber Operated in a Deep Underground Site

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, E.; /Indiana U., South Bend; Behnke, J.; /Indiana U., South Bend; Brice, S.J.; /Fermilab; Broemmelsiek, D.; /Fermilab; Collar, J.I.; /Chicago U., EFI; Conner, A.; /Indiana U., South Bend; Cooper, P.S.; /Fermilab; Crisler, M.; /Fermilab; Dahl, C.E.; /Chicago U., EFI; Fustin, D.; /Chicago U., EFI; Grace, E.; /Indiana U., South Bend /Fermilab

    2012-04-01

    New data are reported from the operation of a 4.0 kg CF{sub 3}I bubble chamber in the 6800 foot deep SNOLAB underground laboratory. The effectiveness of ultrasound analysis in discriminating alpha decay background events from single nuclear recoils has been confirmed, with a lower bound of >99.3% rejection of alpha decay events. Twenty single nuclear recoil event candidates and three multiple bubble events were observed during a total exposure of 553 kg-days distributed over three different bubble nucleation thresholds. The effective exposure for single bubble recoil-like events was 437.4 kg-days. A neutron background internal to the apparatus, of known origin, is estimated to account for five single nuclear recoil events and is consistent with the observed rate of multiple bubble events. This observation provides world best direct detection constraints on WIMP-proton spin-dependent scattering for WIMP masses >20 GeV/c{sup 2} and demonstrates significant sensitivity for spin-independent interactions.

  8. First Dark Matter Search Results from a 4-kg CF$_3$I Bubble Chamber Operated in a Deep Underground Site

    CERN Document Server

    Behnke, E; Brice, S J; Broemmelsiek, D; Collar, J I; Conner, A; Cooper, P S; Crisler, M; Dahl, C E; Fustin, D; Grace, E; Hall, J; Hu, M; Levine, I; Lippincott, W H; Moan, T; Nania, T; Ramberg, E; Robinson, A E; Sonnenschein, A; Szydagis, M; Vázquez-Jáuregui, E

    2012-01-01

    New data are reported from the operation of a 4.0 kg CF$_{3}$I bubble chamber in the 6800 foot deep SNOLAB underground laboratory. The effectiveness of ultrasound analysis in discriminating alpha decay background events from single nuclear recoils has been confirmed, with a lower bound of $>$99.3% rejection of alpha decay events. Twenty single nuclear recoil event candidates and three multiple bubble events were observed during a total exposure of 553 kg-days distributed over three different bubble nucleation thresholds. The effective exposure for single bubble recoil-like events was 437.4 kg-days. A neutron background internal to the apparatus, of known origin, is estimated to account for five single nuclear recoil events and is consistent with the observed rate of multiple bubble events. This observation provides world best direct detection constraints on WIMP-proton spin-dependent scattering for WIMP masses $>$20 GeV/c$^{2}$ and demonstrates significant sensitivity for spin-independent interactions.

  9. Comparison of rechargeable versus battery-operated insulin pumps: temperature fluctuations

    Directory of Open Access Journals (Sweden)

    Vereshchetin P

    2016-10-01

    Full Text Available Paul Vereshchetin, Thomas W McCann Jr, Navdeep Ojha, Ramakrishna Venugopalan, Brian L Levy Johnson & Johnson Diabetes Care Companies, Chesterbrook, PA, USA Abstract: The role of continuous subcutaneous insulin infusion (insulin pumps has become increasingly important in diabetes management, and many different types of these systems are currently available. This exploratory study focused on the reported heating issues that lithium-ion battery-powered pumps may have during charging compared with battery-operated pumps. It was found that pump temperature increased by 6.4°C during a long charging cycle of a lithium-ion battery-operated pump under ambient temperatures. In an environmental-chamber kept at 35°C, the pump temperature increased by 4.4°C, which indicates that the pump temperature was above that of the recommended safety limit for insulin storage of 37°C. When designing new pumps, and when using currently available rechargeable pumps in warmer climates, the implications of these temperature increases should be taken into consideration. Future studies should also further examine insulin quality after charging. Keywords: insulin pumps, diabetes mellitus, safety, heating

  10. Experimental investigations on a common centrifugal pump operating under gas entrainment conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schäfer, Thomas, E-mail: thomas.schaefer@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Neumann, Martin [Technische Universität Dresden, AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering (Germany); Bieberle, André [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Hampel, Uwe [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Technische Universität Dresden, AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering (Germany)

    2017-05-15

    Highlights: • The pump performance has been evaluated for several gas entrainment conditions. • The gas entraining flow regime has a large impact on the pump performance. • High-resolution gamma-ray computed tomography (HireCT) has been applied. • Gas holdup inside the operating impeller has been visualized and quantified. • Gas holdup profiles along selected streamlines have been calculated. - Abstract: This paper presents an experimental study on the effects of additional gas entrainment in centrifugal pumps designed for conveying liquid phases only. The pump performance has been evaluated for several gas entrainment conditions, and for various operational settings of the pump, such as its alignment and the rotational speed of the impeller. As a main performance indicator the impact of entrained gas on the hydraulic power of the pump has been analyzed using experimental data. Additionally, high-resolution gamma-ray computed tomography (HireCT) operated in time-averaged rotation-synchronized scanning mode has been applied to quantify local phase fraction distributions inside the rapidly rotating pump impeller. Based on these quantitative tomographic measurements, gas holdup profiles along selected streamlines have been calculated and gas accumulation areas inside the impeller chambers have been visualized. Thus, various internally accumulated gas holdup patterns have been identified and, eventually, associated with characteristic pump performance behaviors. Moreover, the tomographic measuring method allowed an enhanced gas holdup analysis in specified pump compartments. As a result, the related specific gas and liquid phase holdup profiles have been evaluated.

  11. Study on Operation Optimization of Pumping Station's 24 Hours Operation under Influences of Tides and Peak-Valley Electricity Prices

    Science.gov (United States)

    Yi, Gong; Jilin, Cheng; Lihua, Zhang; Rentian, Zhang

    2010-06-01

    According to different processes of tides and peak-valley electricity prices, this paper determines the optimal start up time in pumping station's 24 hours operation between the rating state and adjusting blade angle state respectively based on the optimization objective function and optimization model for single-unit pump's 24 hours operation taking JiangDu No.4 Pumping Station for example. In the meantime, this paper proposes the following regularities between optimal start up time of pumping station and the process of tides and peak-valley electricity prices each day within a month: (1) In the rating and adjusting blade angle state, the optimal start up time in pumping station's 24 hours operation which depends on the tide generation at the same day varies with the process of tides. There are mainly two kinds of optimal start up time which include the time at tide generation and 12 hours after it. (2) In the rating state, the optimal start up time on each day in a month exhibits a rule of symmetry from 29 to 28 of next month in the lunar calendar. The time of tide generation usually exists in the period of peak electricity price or the valley one. The higher electricity price corresponds to the higher minimum cost of water pumping at unit, which means that the minimum cost of water pumping at unit depends on the peak-valley electricity price at the time of tide generation on the same day. (3) In the adjusting blade angle state, the minimum cost of water pumping at unit in pumping station's 24 hour operation depends on the process of peak-valley electricity prices. And in the adjusting blade angle state, 4.85%˜5.37% of the minimum cost of water pumping at unit will be saved than that of in the rating state.

  12. Simultaneous Imbalance Reduction and Peak Shaving using a Field Operational Virtual Power Plant with Pumps

    NARCIS (Netherlands)

    Pruissen, O.P. van; Kok, J.K.; Eisma, A.

    2015-01-01

    The Dutch electricity infrastructure is challenged by the deployment of large numbers of heat pumps in newly-built domestic residences. An example is the apartment complex of Couperus in The Hague where 300 apartments are heated by individual heat pumps. This building was operated as a Virtual Power

  13. Simultaneous Imbalance Reduction and Peak Shaving using a Field Operational Virtual Power Plant with Pumps

    NARCIS (Netherlands)

    Pruissen, O.P. van; Kok, J.K.; Eisma, A.

    2015-01-01

    The Dutch electricity infrastructure is challenged by the deployment of large numbers of heat pumps in newly-built domestic residences. An example is the apartment complex of Couperus in The Hague where 300 apartments are heated by individual heat pumps. This building was operated as a Virtual Power

  14. Role of Pumped Storage Hydro Resources in Electricity Markets and System Operation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E.; Kirby, B.; Botterud, A.; Milostan, C.; Krad, I.; Koritarov, V.

    2013-05-01

    The most common form of utility- sized energy storage system is the pumped storage hydro system. Originally, these types of storage systems were economically viable simply because they displace more expensive generating units. However, over time, as those expensive units became more efficient and costs declined, pumped hydro storage units no longer have the operational edge. As a result, in the current electricity market environment, pumped storage hydro plants are struggling. To offset this phenomenon, certain market modifications should be addressed. This paper will introduce some of the challenges faced by pumped storage hydro plants in today's markets and purpose some solutions to those problems.

  15. Auto-control of pumping operations in sewerage systems by rule-based fuzzy neural networks

    Science.gov (United States)

    Chiang, Y.-M.; Chang, L.-C.; Tsai, M.-J.; Wang, Y.-F.; Chang, F.-J.

    2011-01-01

    Pumping stations play an important role in flood mitigation in metropolitan areas. The existing sewerage systems, however, are facing a great challenge of fast rising peak flow resulting from urbanization and climate change. It is imperative to construct an efficient and accurate operating prediction model for pumping stations to simulate the drainage mechanism for discharging the rainwater in advance. In this study, we propose two rule-based fuzzy neural networks, adaptive neuro-fuzzy inference system (ANFIS) and counterpropagation fuzzy neural network for on-line predicting of the number of open and closed pumps of a pivotal pumping station in Taipei city up to a lead time of 20 min. The performance of ANFIS outperforms that of CFNN in terms of model efficiency, accuracy, and correctness. Furthermore, the results not only show the predictive water levels do contribute to the successfully operating pumping stations but also demonstrate the applicability and reliability of ANFIS in automatically controlling the urban sewerage systems.

  16. Development, testing, and certification of Calmac Mfg. Corp. solar collector and solar operated pump

    Science.gov (United States)

    Parker, J. C.

    1979-01-01

    Development of a rubber tube solar collector and solar operated pump for use with solar heating and cooling systems is discussed. The development hardware, problems encountered during fabrication and testing, and certification statements of performance are included.

  17. Numerical investigation of the cavitational behaviour into a storage pump at off design operating points

    Energy Technology Data Exchange (ETDEWEB)

    Stuparu, A; Susan-Resiga, R; Anton, L E [Department of Hydraulic Machinery, Politehnica University of Timisoara, Bd. Mihai Viteazu 1, Timisoara, 300222 (Romania); Muntean, S, E-mail: astuparu@mh.mec.upt.r [Centre of Advanced Research in Engineering Science, Romanian Academy-Timisoara Branch, Bd. Mihai Viteazu 24, Timisoara, 300223 (Romania)

    2010-08-15

    The paper presents a new method for the analysis of the cavitational behaviour of hydraulic turbomachines. This new method allows determining the coefficient of the cavitation inception and the cavitation sensitivity of the turbomachines. We apply this method to study the cavitational behaviour of a large storage pump. By plotting in semi-logarithmic coordinates the vapour volume versus the cavitation coefficient, we show that all numerical data collapse in an exponential manner. This storage pump is located in a power plant and operating without the presence of the developed cavitation is vital. We investigate the behaviour of the pump from the cavitational point of view while the pump is operating for variable discharge. A distribution of the vapour volume upon the blade of the impeller is presented for all the four operating points. It can be seen how the volume of vapour evolves from one operating point to another. In order to study the influence of the cavitation phenomena upon the pump, the evolution of the pumping head against the cavitation coefficient is presented. That will show how the pumping head drops while the cavitation coefficient decreases. From analysing the data obtained from the numerical simulation it results that the cavitation phenomena is present for all the investigated operating points. By analysis of the slope of the curve describing the evolution of the vapour volume against the cavitation coefficient we determine the cavitation sensitivity of the pump for each operating point. It is showed that the cavitation sensitivity of the investigated storage pump increases while the flow rate decreases.

  18. Simulation model of a variable-speed pumped-storage power plant in unstable operating conditions in pumping mode

    Science.gov (United States)

    Martínez-Lucas, G.; Pérez-Díaz, J. I.; Sarasúa, J. I.; Cavazzini, G.; Pavesi, G.; Ardizzon, G.

    2017-04-01

    This paper presents a dynamic simulation model of a laboratory-scale pumped-storage power plant (PSPP) operating in pumping mode with variable speed. The model considers the dynamic behavior of the conduits by means of an elastic water column approach, and synthetically generates both pressure and torque pulsations that reproduce the operation of the hydraulic machine in its instability region. The pressure and torque pulsations are generated each from a different set of sinusoidal functions. These functions were calibrated from the results of a CFD model, which was in turn validated from experimental data. Simulation model results match the numerical results of the CFD model with reasonable accuracy. The pump-turbine model (the functions used to generate pressure and torque pulsations inclusive) was up-scaled by hydraulic similarity according to the design parameters of a real PSPP and included in a dynamic simulation model of the said PSPP. Preliminary conclusions on the impact of unstable operation conditions on the penstock fatigue were obtained by means of a Monte Carlo simulation-based fatigue analysis.

  19. Influence of pumping operational schedule on solute concentrations at a well in randomly heterogeneous aquifers

    Science.gov (United States)

    Libera, Arianna; de Barros, Felipe P. J.; Guadagnini, Alberto

    2017-03-01

    We investigate the way diverse groundwater extraction strategies affect the history of solute concentration recovered at a pumping well while taking into account random spatial variability of the system hydraulic conductivity. Considering the joint effects of spatially heterogeneous hydraulic conductivity and temporally varying well pumping rates leads to a realistic evaluation of groundwater contamination risk at the pumping well location. We juxtapose the results obtained when the pumping well extracts a given amount of water operating (a) at a uniform pumping rate and (b) under a transient regime. The analysis is performed within a numerical Monte Carlo framework. Our results show that contaminant concentration breakthrough curves (BTCs) at the well are markedly affected by the transient pumping strategy according to which the well is operated. Our results document the occurrence in time of multiple peaks in the mean and variance of flux-averaged concentrations at the extraction well operating at a transient rate. Our findings suggest that lowest and largest values of mean and variance of flux-averaged concentration at the well tend to occur at the same time. We show that uncertainty associated with detected BTCs at the well increases for pumping regimes displaying a high degree of temporal variability. As such, the choice of the type of engineering control to the temporal sequence of pumping rates could represent a key factor to drive quantification of uncertainty of the contaminant concentration detected at the well. It is documented that pumping rate fluctuations induce a temporally oscillating risk pattern at the well, thus suggesting that the selection of a dynamic pumping regime has a clear influence on the temporal evolution of risk at the well.

  20. High power operation of cladding pumped holmium-doped silica fibre lasers.

    Science.gov (United States)

    Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

    2013-02-25

    We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 µm pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 µm demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency.

  1. Research on Optimal Operation by Adjusting Blade Angle in Jiangdu No. 4 Pumping Station of China

    Science.gov (United States)

    Lihua, Zhang; Jilin, Chang; Rentian, Zhang; Yi, Gong

    2010-06-01

    A Nonlinear Programming Model for the optimal day-operation of multi-units pump in one pumping station by adjusting blade angle has been put out, where the peak-valley electricity prices is considered in this paper. The model takes the minimal operation cost of pump assembly as objective function. In the meantime, the periods are defined as stage variables. The blade angle and the number of the working-pumps are expressed as decision variables and the water volume pumped in one day as constraint condition. The problem is very difficult to be settled by regular methods. This paper presents a new method which adopts experimental optimization method of adjusting blade angle in different periods and linear integral programming method to select the number of pumps. After applying the method to the optimal operation of Jiangdu No.4 pumping station, which is the source pump station of Eastern Route Project of South-to-North Water Diversion(Where there are seven pumps and the design flow rate of single-unit is 30.0m3/sec), we get the results which are as follows:(1) With the constraint conditions of typical tidal process which are average tidal levels from December to February of next year, designed average pumping head of 7.8m, and the operation load at 100%,80%,60% of full-load(the water volume when the pumps working with the blade angle of 0 degree and the speed of 150r/min in full day), the relative energy-saving reaches 5.18%˜33.02% comparing with the state of keeping the pump operating at its designed blade angle which is 0 degree when considering peak-valley electricity prices. While not considering the peak-valley electricity prices, the number is 1.96%˜9.71%, and less load corresponds to more cost-saving. (2) The key factory on deciding the operation state of pumps is electricity price when we consider the peak-valley electricity prices. All the pumps should be working and the blade angle should be in the largest state when at the valley price, while the number

  2. Direct imaging of the dynamics of a laser-plasma accelerator operating in the bubble-regime

    CERN Document Server

    Sävert, A; Schnell, M; Cole, J M; Nicolai, M; Reuter, M; Schwab, M B; Möller, M; Poder, K; Jäckel, O; Paulus, G G; Spielmann, C; Najmudin, Z; Kaluza, M C

    2014-01-01

    Laser-plasma accelerators operating in the bubble-regime generate quasi-monoenergetic multi-gigaelectronvolt electron beams with femtosecond duration and micrometre size. These beams are produced by accelerating in laser-driven plasma waves in only centimetre distances. Hence they have the potential to be compact alternatives to conventional accelerators. However, since the plasma wave moves at ultra-relativistic speed making detailed observation extremely difficult, most of our current understanding has been gained from high-performance computer simulations. Here, we present experimental results from an ultra-fast optical imaging technique visualising for the first time the non-linear dynamics in a laser-plasma accelerator. By freezing the relativistic motion of the plasma wave, our measurements reveal insight of unprecedented detail. In particular, we observe the plasma wave's non-linear formation, breaking, and transformation into a single bubble for the first time. Understanding the acceleration dynamics ...

  3. Study on operation of a research reactor during one PCS pump failure accident

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Kyoung Woo; Yoon, Hyu Ngi; Kim, Seong Hoon; Chi, Dae Young; Yoon, Juh Yeon [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    The Primary cooling system (PCS) of a research reactor is designed to provide adequate cooling to the reactor core with a reasonable margin during all operation modes. The PCS consists of pumps, heat exchangers, and all necessary interconnecting pipes, valves, and instruments. The number of pumps is determined from a safety and economic point of view. As the number of pump trains increase, the cost increases according to the increase in safety class equipment. However, it is impossible to install one pump for a PCS because a zero flow can instantaneously occur during a pump failure such as a pump seizure. Thus, a PCS frequently consists of two parallel 50% capacity pumps and heat exchangers. In addition, check valves are generally installed to prevent a reversal flow when multiple pumps are designed to operate. However, if a swing type check valve is used, it should be estimated whether the slam due to instantaneous closing of the valve affects the system vibration. To reduce the vibration by a slam phenomenon, additional equipment such as a damper will be installed in the valve. The purpose of the check valve in PCS is to prevent the flow path when a reverse flow occurs. The installation of additional equipment will make it difficult to perform this function. In this study, it is estimated whether the PCS can operate without check valves. First, a flow analysis using Flowmaster was compared and verified by the calculation employing a empirical correlation. Second, the simulation for a one pump failure accident was performed and analyzed.

  4. Influence of hydrophibization of impellers of centrifugal pumps on their operating characteristics

    Science.gov (United States)

    Volkov, A. V.; Parygin, A. G.; Naumov, A. V.; Vikhlyantsev, A. A.; Šoukal, J.; Sedlář, M.; Komárek, M.

    2016-12-01

    This work presents experimental estimation results of changing of basic operation characteristics of a group of centrifugal pumps covering a range of values of dimensionless power-speed coefficient n s from 33 to 330 after hydrophobization of their impellers' surfaces. Hydrophobization of functional surfaces of impellers in all experiments was performed by formation of structures of organic covers by technology of MPEI NRU, which provides increasing of limiting wetting angle of surfaces to 120° and greater. Results of experimental researches of the influence of hydrophobization of impeller surfaces for high-speed pump ( n s = 330) on its characteristics is presented for the first time. Positive effect of applying hydrophobization technology to impeller surfaces in all the considered range of power-speed coefficient was generalized and estimated. It was shown that hydrophobization of impeller surfaces of centrifugal pumps provides increment to their efficiency factors within an acceptable operation range from 0.5 to 7.5%. Empiric function defining dependencies of efficiency factor increment of pump on relative supply and power-speed coefficient are suggested. Possibilities and estimation of extending acceptable operation range of a pump depending on powerspeed coefficient as a result of impeller surface hydrophobization are shown. Experimental data of comparative cavitation tests of high-speed pumps before and after hydrophobization of their impeller surfaces are generalized for the first time for considered range of power-speed coefficient values. The influence of power-speed coefficient on changing of critical net pump suction head (critical positive suction pressure) is shown. Based on existing knowledge on pumps, an attempt to validate experimentally obtained lows of changing of power and anticavitation features of centrifugal pumps after hydrophobization of their impeller surfaces is made.

  5. Optimal Operation for Baoying Pumping Station in East Route Project of South-to-North Water Transfer

    Institute of Scientific and Technical Information of China (English)

    FENG Xiaoli; QIU Baoyun; CAO Haihong; WEI Qianglin; TENG Haibo

    2009-01-01

    Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjustable blade, mathematical models of pumping station optimal operation are established and solved with genetic algorithm. For different total pumping discharge and total pumping volume of water per day, in order to minimize pumping station operation cost, the number and operation duties of running pump units are respectively determined at different periods of time in a day. The results indicate that the saving of electrical cost is significantly effected by the schemes of adjusting blade angles and time-varying electrical price when pumping certain water volume of water per day, and compared with conventional operation schemes (namely, the schemes of pumping station operation at design blade angles based on certain pumping discharge), the electrical cost is saved by 4.73%-31.27%. Also, compared with the electrical cost of conventional operation schemes, the electrical cost is saved by 2.03%-5.79% by the schemes of adjusting blade angles when pumping certain discharge.

  6. Continuous-wave operation of a room-temperature Tm: YAP-pumped Ho: YAG laser

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We report a continuous-wave (CW) 2.1-μm Ho:YAG laser operating at room temperature pumped by a diode-pumped 1.94-?m Tm:YAP laser.The maximum output power of 1.5 W is obtained from Ho:YAG laser,corresponding to Tm-to-Ho slope efficiency of 17.9% and diode-to-He conversion efficiency of 5.6%.

  7. Auto-control of pumping operations in sewerage systems by rule-based fuzzy neural networks

    OpenAIRE

    Chiang, Y.-M.; Chang, L.-C.; Tsai, M.-J.; Wang, Y. -F.; Chang, F.-J.

    2011-01-01

    Pumping stations play an important role in flood mitigation in metropolitan areas. The existing sewerage systems, however, are facing a great challenge of fast rising peak flow resulting from urbanization and climate change. It is imperative to construct an efficient and accurate operating prediction model for pumping stations to simulate the drainage mechanism for discharging the rainwater in advance. In this study, we propose two rule-based fuzzy neural networks, adaptive neuro-fuzzy infere...

  8. Parallel Operation Characteristics Analysis of Sewage Source Heat Pump Units in Winter

    Institute of Scientific and Technical Information of China (English)

    庄兆意; 张承虎; 王海燕; 孙德兴

    2010-01-01

    Sewage source heat pump unit operates under partial load most of the time, and study on the law of coefficient of performance (COP) of the unit varying with load ratio can provide basis for the heat pump units running in high efficiency. A mathematical model determining COP, evaporation temperature and condensation temperature of a single unit was proposed. Under the condition of uniform load distribution, the model was established according to different ways of bearing partial load with the same type multi...

  9. Bubble-Free Operation of a Microfluidic Free-Flow Electrophoresis Chip with Integrated Pt Electrodes

    NARCIS (Netherlands)

    Kohlheyer, Dietrich; Eijkel, Jan C.T.; Schlautmann, Stefan; Berg, van den Albert; Schasfoort, Richard B.M.

    2008-01-01

    In order to ensure a stable and efficient separation in microfluidic free-flow electrophoresis (FFE) devices, various methods and chips have been presented until now. A major concern hereby is the generation of gas bubbles caused by electrolysis and the resulting disturbances in the position of the

  10. Operational test for photovoltaic pumping systems; Procedimento para averiguacao operacional de sistemas fotovoltaicos de bombeamento

    Energy Technology Data Exchange (ETDEWEB)

    Fedrizzi, Maria Cristina; Brito, Alaan Ubaiara; Zilles, Roberto [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Lab. de Sistemas Fotovoltaicos], e-mail: fedrizzi@iee.usp.br, e-mail: alaan@iee.usp.br, e-mail: zilles@iee.usp.br

    2004-07-01

    This paper presents an operational test for photovoltaic pumping systems daily production, m{sup 3}/dia. The procedure does not involve expensive instrumentation and is easy to be applied in the field as acceptance and qualification tools. In this way, the paper presents the boundary conditions for operational test accomplishment that allows its application. (author)

  11. Operational cost minimization of heat pump for milk pasteurization in dairy.

    Science.gov (United States)

    Söylemez, Mehmet Sait

    2005-11-01

    A thermo economic optimization analysis is presented yielding simple algebraic formula for estimating the optimum operating conditions of interconnected heat pump assisted milk pasteurizing systems. The overall operational cost method including the cost of auxiliary heater is used in the present study, together with the thermal analyses of all system components, for thermo economic analysis of the system.

  12. Induction Motors Most Efficient Operation Points in Pumped Storage Systems

    DEFF Research Database (Denmark)

    Busca-Forcos, Andreea; Marinescu, Corneliu; Busca, Cristian

    2015-01-01

    efficiency is desired especially when operating with renewable energy systems, which present low energy conversion factor (up to 50% - performance coefficient for wind turbines, and efficiency up to 40% for photovoltaic systems). In this paper the most efficient operation points of the induction motors...

  13. Large-Scale Pumping Test Recommendations for the 200-ZP-1 Operable Unit

    Energy Technology Data Exchange (ETDEWEB)

    Spane, Frank A.

    2010-09-08

    CH2M Hill Plateau Remediation Company (CHPRC) is currently assessing aquifer characterization needs to optimize pump-and-treat remedial strategies (e.g., extraction well pumping rates, pumping schedule/design) in the 200-ZP-1 operable unit (OU), and in particular for the immediate area of the 241 TX-TY Tank Farm. Specifically, CHPRC is focusing on hydrologic characterization opportunities that may be available for newly constructed and planned ZP-1 extraction wells. These new extraction wells will be used to further refine the 3-dimensional subsurface contaminant distribution within this area and will be used in concert with other existing pump-and-treat wells to remediate the existing carbon tetrachloride contaminant plume. Currently, 14 extraction wells are actively used in the Interim Record of Decision ZP-1 pump-and-treat system for the purpose of remediating the existing carbon tetrachloride contamination in groundwater within this general area. As many as 20 new extraction wells and 17 injection wells may be installed to support final pump-and-treat operations within the OU area. It should be noted that although the report specifically refers to the 200-ZP-1 OU, the large-scale test recommendations are also applicable to the adjacent 200-UP-1 OU area. This is because of the similar hydrogeologic conditions exhibited within these two adjoining OU locations.

  14. Operation of large-scale pumps and valves in molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.C. (Science Applications International Corp., Albuquerque, NM (United States)); Rush, E.E.; Matthews, C.W.; Chavez, J.M. (Sandia National Labs., Albuquerque, NM (United States)); Bator, P.A. (Babcock and Wilcox Co., Barberton, OH (United States))

    1994-08-01

    The molten salt pump and valve (P and V) test loops at Sandia National Laboratories (SNL) National Solar Thermal Test Facility (NSTTF) operated between Jan. 1988 and Oct. 1990. The purpose of the P and V test was to demonstrate the performance, reliability, and service life of full-scale hot and cold salt pumps and valves for use in commercial central receiver solar power plants. The P and V test hardware consists of two pumped loops; the Hot Loop'' to simulate the hot (565 C) side of the receiver and the Cold Loop'' to simulate the receiver's cold (285 C) side. Each loop contains a pump and five valves sized to be representative of a conceptual 60-MW(e) commercial solar power plant design. The hot loop accumulated over 6,700 hours of operation and the cold loop over 2,500 hours of operation. This project has demonstrated that standard commercial scale pump and valve designs will work in molten salt. The test also exposed some pitfalls that must be avoided in specifying such equipment. Although certainly not all of the pitfalls were discovered, careful design and specification should result in reliable or at least workable equipment.

  15. Simultaneous transient operation of a high head hydro power plant and a storage pumping station in the same hydraulic scheme

    Science.gov (United States)

    Bucur, D. M.; Dunca, G.; Cervantes, M. J.; Cǎlinoiu, C.; Isbǎşoiu, E. C.

    2014-03-01

    This paper presents an on-site experimental analysis of a high head hydro power plant and a storage pumping station, in an interconnected complex hydraulic scheme during simultaneous transient operation. The investigated hydropower site has a unique structure as the pumping station discharges the water into the hydropower plant penstock. The operation regimes were chosen for critical scenarios such as sudden load rejections of the turbines as well as start-ups and stops with different combinations of the hydraulic turbines and pumps operation. Several parameters were simultaneously measured such as the pumped water discharge, the pressure at the inlet pump section, at the outlet of the pumps and at the vane house of the hydraulic power plant surge tank. The results showed the dependence of the turbines and the pumps operation. Simultaneous operation of the turbines and the pumps is possible in safe conditions, without endangering the machines or the structures. Furthermore, simultaneous operation of the pumping station together with the hydropower plant increases the overall hydraulic efficiency of the site since shortening the discharge circuit of the pumps.

  16. Modeling and numerical simulation of a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage

    Institute of Scientific and Technical Information of China (English)

    QIU Jia; LIANG Jian; CHEN GuangMing; DU RuXu

    2009-01-01

    This paper presents a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage. It solves the problem of unreliable solar energy supply by storing the working fluids and hence, functions 24 h per day. First, the working principles are described and the dynamic models for the primary energy storage components are developed. Then, the system is evaluated based on a numerical simulation. Based on the meteorological data of a typical day in a subtropical area, with the area of a solar collector being set at 19.15 m2, whilst the initial charging mass, mass fraction and temperature of the solution are respectively set at 379.5 kg, 54.16% and 34.5 ℃, it is found that the respective coefficients of performance (COP) of the air conditioning system and the en-tire system (including the solar panel) are 0.7771 and 0.4372. In particular, the energy storage density of the system is 206.69 MJ/m3 which is much greater than those of chilled water or hot water storage systems under comparable conditions. This makes the new system much more compact and efficient. Finally, an automatic control strategy is given to achieve the highest COP when solar energy fluctuates.

  17. Gargamelle : this film recalls design, construction and operation of this heavy liquid bubble chamber named thus for its size of giantess

    CERN Multimedia

    Sidney Jezequel

    1971-01-01

    1970 : in the Saclay Nuclear Research Center, the assembly of the two largest bubble chambers ever built was in the final stage; Mirabelle for the Soviet Serpukhov accelerator and Gargamelle for the CERN European accelerator ... Comments : Saturn particle accelerator at Saclay, most powerful in 1959. Since then: ISR, Brookhaven, Serpakov. History of bubble chambers. Ecole Polytechnique. Gargamelle, Rabelais legendary giant, wife of Gargantua. Demands of building of chamber body. Bubble chamber a kind of photographers studio. Animation explaining how a bubble chamber works. Decompression/recompression cycle. Film. * Most dramatic moment in film is when the man enters the chamber to paint it with an absolute photographic black. Magnet. Largest conventional magnet every built. Could compare that with the L3 magnet, to get a feel for the size expansion in 15 years. Assembly at CERN. Cost $5.000.000. Operation. Scanning. Ends with need to build bigger machines to get at secrets of nature. In a few years Gargamell...

  18. Operational comparison of bubble (super heated drop) dosimetry with routine albedo TLD for a selected group of Pu-238 workers at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L.L.; Hoffman, J.M.; Foltyn, E.M.; Buhl, T.E.

    1998-09-01

    Personnel neutron dosimetry continues to be a difficult science due to the lack of availability of robust passive dosimeters that exhibit tissue- or near-tissue- equivalent response. This paper is an operational study that compares the use of albedo thermoluminescent dosimeters with bubble dosimeters to determine whether bubble dosimeters do provide a useful daily ALARA tool that can yield measurements close to the dose-of-record. A group of workers at Los Alamos National Laboratory (LANL) working on the Radioisotopic Thermoelectric Generators (RTG) for the NASA Cassini space mission wore both bubble dosimeters and albedo dosimeters over a period from 1993 through 1996. The personal albedo dosimeter was processed on a monthly basis and used as the dose-of-record. The results of this study indicated that cumulative daily bubble dosimetry results agreed with whole-body albedo dosimetry results within about 37% on average.

  19. Auto-control of pumping operations in sewerage systems by rule-based fuzzy neural networks

    Directory of Open Access Journals (Sweden)

    Y.-M. Chiang

    2010-09-01

    Full Text Available Pumping stations play an important role in flood mitigation in metropolitan areas. The existing sewerage systems, however, are facing a great challenge of fast rising peak flow resulting from urbanization and climate change. It is imperative to construct an efficient and accurate operating prediction model for pumping stations to simulate the drainage mechanism for discharging the rainwater in advance. In this study, we propose two rule-based fuzzy neural networks, adaptive neuro-fuzzy inference system (ANFIS and counterpropagatiom fuzzy neural network (CFNN for on-line predicting of the number of open and closed pumps of a pivotal pumping station in Taipei city up to a lead time of 20 min. The performance of ANFIS outperforms that of CFNN in terms of model efficiency, accuracy, and correctness. Furthermore, the results not only show the predictive water levels do contribute to the successfully operating pumping stations but also demonstrate the applicability and reliability of ANFIS in automatically controlling the urban sewerage systems.

  20. Auto-control of pumping operations in sewerage systems by rule-based fuzzy neural networks

    Directory of Open Access Journals (Sweden)

    Y.-M. Chiang

    2011-01-01

    Full Text Available Pumping stations play an important role in flood mitigation in metropolitan areas. The existing sewerage systems, however, are facing a great challenge of fast rising peak flow resulting from urbanization and climate change. It is imperative to construct an efficient and accurate operating prediction model for pumping stations to simulate the drainage mechanism for discharging the rainwater in advance. In this study, we propose two rule-based fuzzy neural networks, adaptive neuro-fuzzy inference system (ANFIS and counterpropagation fuzzy neural network for on-line predicting of the number of open and closed pumps of a pivotal pumping station in Taipei city up to a lead time of 20 min. The performance of ANFIS outperforms that of CFNN in terms of model efficiency, accuracy, and correctness. Furthermore, the results not only show the predictive water levels do contribute to the successfully operating pumping stations but also demonstrate the applicability and reliability of ANFIS in automatically controlling the urban sewerage systems.

  1. Enhanced technical and economic working domains of industrial heat pumps operated in series

    DEFF Research Database (Denmark)

    Ommen, Torben; Jensen, Jonas Kjær; Markussen, Wiebke Brix

    2015-01-01

    By operating heat pumps (HPs) in series, it is possible to obtain closer match between working fluid and sink- and source streams, resulting in higher coefficient of performance (COP). For industrial HPs, it was found that serial connection of either two or three units results in an increase in COP...

  2. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    NARCIS (Netherlands)

    van Eck, H. J. N.; Koppers, W. R.; van Rooij, G. J.; W. J. Goedheer,; Engeln, R.; D.C. Schram,; Cardozo, N. J. L.; Kleyn, A. W.

    2009-01-01

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial mag

  3. Diode-pumped intracavity optical parametric oscillator in pulsed and continuous-wave operation

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Skettrup, Torben; Petersen, O.B.;

    2002-01-01

    An intracavity optical parametric oscillator is investigated in pulsed and continuous-wave operation. The intracavity optical parametric oscillator is based on Yb:YAG as the laser material and a periodically poled lithium niobate crystal as the nonlinear material. Tuneable idler output powers above...... 200 mW are obtained in both modes of operation with 13.5 W of incident diode pump power. The idler output was tuned in the wavelength range 3820-4570 nm....

  4. End-pumped 1.5 microm monoblock laser for broad temperature operation.

    Science.gov (United States)

    Schilling, Bradley W; Chinn, Stephen R; Hays, A D; Goldberg, Lew; Trussell, C Ward

    2006-09-01

    We describe a next-generation monoblock laser capable of a greater than 10 mJ, 1.5 microm output at 10 pulses/s (pps) over broad ambient temperature extremes with no active temperature control. The transmitter design is based on a Nd:YAG laser with a Cr4+ passive Q switch and intracavity potassium titanyl phosphate optical parametric oscillator. To achieve the repetition rate and efficiency goals of this effort, but still have wide temperature capability, the Nd:YAG slab is end pumped with a 12-bar stack of 100 W (each) diode bars. Different techniques for focusing the pump radiation into the 4.25 mmx4.25 mm end of the slab are compared, including a lensed design, a reflective concentrator, and a lens duct. A wide temperature operation (-20 degrees C to 50 degrees C) for each end-pumped configuration is demonstrated.

  5. Operation ranges and dynamic capabilities of variable-speed pumped-storage hydropower

    Science.gov (United States)

    Mercier, Thomas; Olivier, Mathieu; Dejaeger, Emmanuel

    2017-04-01

    The development of renewable and intermittent power generation creates incentives for the development of both energy storage solutions and more flexible power generation assets. Pumped-storage hydropower (PSH) is the most established and mature energy storage technology, but recent developments in power electronics have created a renewed interest by providing PSH units with a variable-speed feature, thereby increasing their flexibility. This paper reviews technical considerations related to variable-speed PSH in link with the provision of primary frequency control, also referred to as frequency containment reserves (FCRs). Based on the detailed characteristics of a scale model pump-turbine, the variable-speed operation ranges in pump and turbine modes are precisely assessed and the implications for the provision of FCRs are highlighted. Modelling and control for power system studies are discussed, both for fixed- and variable-speed machines and simulation results are provided to illustrate the high dynamic capabilities of variable-speed PSH.

  6. Operational performance of the photovoltaic-powered grain mill and water pump at Tangaye, Upper Volta

    Science.gov (United States)

    Martz, J. E.; Ratajczak, A. F.; Delombard, R.

    1982-01-01

    The first two years of operation of a stand alone photovoltaic (PV) power system for the village of Tangaye, Upper Volta in West Africa are described. The purpose of the experiment was to demonstrate that PV systems could provide reliable electrical power for multiple use applications in remote areas where local technical expertise is limited. The 1.8 kW (peak) power system supplies 120-V (d.c.) electrical power to operate a grain mill, a water pump, and mill building lights for the village. The system was initially sized to pump a part of the village water requirements from an existing improved well, and to meet a portion of the village grain grinding requirements. The data, observations, experiences, and conclusions developed during the first two years of operation are discussed. Reports of tests of the mills used in the project are included.

  7. Fiber laser pumped burst-mode operated picosecond mid-infrared laser

    Institute of Scientific and Technical Information of China (English)

    魏凯华; 姜培培; 吴波; 陈滔; 沈永行

    2015-01-01

    We demonstrate a compact periodically poled MgO-doped lithium niobate (MgO:PPLN)-based optical parametric oscillator (OPO) quasi-synchronously pumped by a fiber laser system with burst-mode operation. The pump source is a peak-power-selectable pulse-multiplied picosecond Yb fiber laser. The chirped pulses from a figure of eight-cavity mode-locked fiber laser seed are narrowed to a duration of less than 50 ps using an FBG refl ector and a circulator. The narrowed pulses are directed to pass through a pulse multiplier and to form pulse bunches, each of which is composed of 13 sub-pulses. The obtained pulse bunches are amplified by two-stage fiber pre-amplifiers:one-stage is core-pumped and the other is cladding-pumped. A fiberized acousto–optic modulator is inserted to control the pulse repetition rate (PRR) of the pulse bunches before they are power-amplified in the final amplifier stage with a large mode area (LMA) PM Yb-doped fiber. The maximum average powers from the final amplifier are 85 W, 60 W, and 45 W respectively, corresponding to the PRR of 2.72 MHz, 1.36 MHz, and 0.68 MHz. The amplified pulses are directed to pump an MgO:PPLN-based optical parametric oscillator (OPO). A maximum peak power at 3.45 µm is obtained approximately to be 8.4 kW. Detailed performance characteristics are presented.

  8. Microfluidic bubble logic.

    Science.gov (United States)

    Prakash, Manu; Gershenfeld, Neil

    2007-02-09

    We demonstrate universal computation in an all-fluidic two-phase microfluidic system. Nonlinearity is introduced into an otherwise linear, reversible, low-Reynolds number flow via bubble-to-bubble hydrodynamic interactions. A bubble traveling in a channel represents a bit, providing us with the capability to simultaneously transport materials and perform logical control operations. We demonstrate bubble logic AND/OR/NOT gates, a toggle flip-flop, a ripple counter, timing restoration, a ring oscillator, and an electro-bubble modulator. These show the nonlinearity, gain, bistability, synchronization, cascadability, feedback, and programmability required for scalable universal computation. With increasing complexity in large-scale microfluidic processors, bubble logic provides an on-chip process control mechanism integrating chemistry and computation.

  9. Unintended Insulin Pump Delivery in Hyperbaric Conditions.

    Science.gov (United States)

    Bertuzzi, Federico; Pintaudi, Basilio; Bonomo, Matteo; Garuti, Fabio

    2017-04-01

    Unintended pump insulin delivery was reported to occur as a consequence of decreased atmospheric pressure, probably mediated by air bubble formation and the expansion of existing bubbles. This observation has been used to explain some hypoglycemic episodes occurring in patients on insulin pump treatment in between 1 and 1 h 45 min after the flight takeoff. New models of insulin pumps have been introduced in the market, most of them are waterproof certified. It is not clear if in these new pumps the influence of atmospheric pressure changes on the insulin delivery is still present. Moreover, there are no evidences related to the insulin pump operations in hyperbaric conditions, like as during diving activities. Our aim is therefore to verify the eventual variation of insulin pump delivery determined by atmospheric pressure changes in hyperbaric conditions. Three new models of insulin pumps were tested in hyperbaric conditions at a flow rate of 2 U/h. Atmospheric pressure variation affected pump insulin release. An increase in the atmospheric pressure from 1 to 1.3 atmosphere (ATA) induced a decrease of pump basal insulin release (about -0.2 U/10 min); conversely, when the atmospheric pressure returned from 1.3 to 1 ATA, an unintended insulin delivery was observed (about +0.3 U/10 min). This phenomenon appeared to be independent of the insulin pump rate and dependent on the presence of air bubbles within the insulin tube setting and cartridge. Unintended insulin delivery driven by atmospheric pressure changes in hyperbaric conditions occurred in the new insulin pumps available. Patients should pay attention to possible variation of insulin rate during the flight or during diving activities.

  10. Belmont Hyperthermia Pump in the conduct of intra-operative heated chemotherapy.

    Science.gov (United States)

    Riley, W

    2009-03-01

    Intra-operative heated chemotherapy (IOHC) has been performed in the Thoracic surgical department of Brigham and Women's Hospital (BWH, Boston, MA, USA) for over a decade. A "home-grown" system was developed for this purpose with limited improvements made to it through the years. This technology is used for neo-adjuvant therapy in the conduct of extra-pleural pneumonectomy and pleurectomy for treatment of mesothelioma. Improvements to the traditional BWH system were sought due to the hazardous nature of the chemotherapy solution and the relative complexity of the IOHC circuit. Belmont Instrument (Belmont Instrument Corporation, Billerica, MA, USA) applied their proprietary infusion/warming technology to develop the Belmont Hyperthermia Pump. The Hyperthermia Pump was designed to recirculate large volumes of fluid while maintaining perfusate temperatures up to 46oC at a flow rate of up to 750 ml/min. Approval from the FDA for clinical use of this device was granted June 2007. Parameters were defined and investigated to determine if the Hyperthermia Pump would meet or exceed the performance characteristics of the traditional BWH system. Our investigation resulted in the replacement of the traditional BWH circuit. The Belmont Hyperthermia Pump is a compact, easy to use, extremely safe means to deliver intra-operative hyperthermic chemotherapy in the conduct of surgical treatment of mesothelioma.

  11. Diode-pumped Q-switched Nd{sup 3+} : YAG laser operating in a wide temperature range without thermal stabilisation of pump diodes

    Energy Technology Data Exchange (ETDEWEB)

    Vainshenker, A E; Vilenskiy, A V; Kazakov, A A; Lysoy, B G; Mikhailov, L K; Pashkov, V A [Open Joint-Stock Company ' M.F. Stel' makh Polyus Research and Development Institute' , Moscow (Russian Federation)

    2013-02-28

    A model sample of a compact low-power-consumption Nd{sup 3+} : YAG laser emitting 20-mJ pulses with a pulse repetition rate up to 20 Hz (in cyclic duty) at a wavelength of 1064 nm is developed and studied. The laser is designed for operating at external temperatures from -40 to +50 deg C. This was achieved by using quasi-end diode pumping without thermal stabilisation of pump diodes. (laser optics 2012)

  12. Science Bubbles

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Pedersen, David Budtz

    2013-01-01

    Much like the trade and trait sof bubbles in financial markets,similar bubbles appear on the science market. When economic bubbles burst, the drop in prices causes the crash of unsustainable investments leading to an investor confidence crisis possibly followed by a financial panic. But when...... bubbles appear in science, truth and reliability are the first victims. This paper explores how fashions in research funding and research management may turn science into something like a bubble economy....

  13. Operational Test Report (OTR) for U-102 Pumping and Instrumentation and Control (PIC) Skid

    Energy Technology Data Exchange (ETDEWEB)

    KOCH, M.R.

    2000-02-28

    Attached is the completed Operation Test Procedure (OTP-200-004, Rev. A-19 and Rev. A-20). OTP includes a print out of the Programmable Logic Controller (PLC) Ladder Diagram. Ladder Diagram was designed for installation in the PLC used to monitor and control pumping activity for Tank Farm 241-U-102. The completed OTP and OTR are referenced in the IS PIC Skid Configuration Drawing (H-2-829998).

  14. Operational Test Report (OTR) for U-103 Pumping and Instrumentation and Control (PIC) Skid

    Energy Technology Data Exchange (ETDEWEB)

    KOCH, M.R.

    2000-02-28

    Attached is the completed Operation Test Procedure (OTP-200-004, Rev. A-16). OTP includes a print out of the Programmable Logic Controller (PLC) Ladder Diagram. Ladder Diagram was designed for installation in the PLC used to monitor and control pumping activity for Tank Farm 241-U-103. The completed OTP and OTR are referenced in the 25 PIC Skid Configuration Drawing (H-2-829998).

  15. Operational Test Report (OTR) for U-105 Pumping and Instrumentation and Control (PIC) Skid

    Energy Technology Data Exchange (ETDEWEB)

    KOCH, M.R.

    2000-02-28

    Attached is the completed Operation Test Procedure (OTP-200-004, Rev. A-18). OTP includes a print out of the Programmable Logic Controller (PLC) Ladder Diagram. Ladder Diagram was designed for installation in the PLC used to monitor and control pumping activity for Tank Farm 241-U-105. The completed OTP and OTR are referenced in the IS PIC Skid Configuration Drawing (H-2-829998).

  16. Fluid circulating pump operated by same incident solar energy which heats energy collection fluid

    Science.gov (United States)

    Collins, E. R.

    1980-01-01

    The application of using a spacecraft solar powered pump terrestrially to reduce or eliminate the need for fossil fuel generated electricity for domestic solar hot water systems was investigated. A breadboard prototype model was constructed utilizing bimetals to convert thermal energy into mechanical motion by means of a toggle operated shutter mechanism. Although it did not meet expected thermal efficiency, the prototype model was sufficient to demonstrate the mechanical concept.

  17. Thermodynamic analysis of a thermally operated cascade sorption heat pump for continuous cold generation

    OpenAIRE

    P. Muthukumar, D.V.N. Lakshmi

    2013-01-01

    In this paper, the thermodynamic analysis of a cascade sorption system consists of a two-stage metal hydride heat pump as topping cycle and a single-stage lithium bromide water system as bottom cycle is presented. The effects of various operating temperatures such as driving heat, heat release and refrigeration temperatures, and design parameters such as ratio of metal hydride mass to reactor mass and sensible heat exchange factor on the combined coefficient of performance (COP) of the cascad...

  18. Vapor Bubbles

    Science.gov (United States)

    Prosperetti, Andrea

    2017-01-01

    This article reviews the fundamental physics of vapor bubbles in liquids. Work on bubble growth and condensation for stationary and translating bubbles is summarized and the differences with bubbles containing a permanent gas stressed. In particular, it is shown that the natural frequency of a vapor bubble is proportional not to the inverse radius, as for a gas bubble, but to the inverse radius raised to the power 2/3. Permanent gas dissolved in the liquid diffuses into the bubble with strong effects on its dynamics. The effects of the diffusion of heat and mass on the propagation of pressure waves in a vaporous bubbly liquid are discussed. Other topics briefly touched on include thermocapillary flow, plasmonic nanobubbles, and vapor bubbles in an immiscible liquid.

  19. Closed-loop helium circulation system for actuation of a continuously operating heart catheter pump.

    Science.gov (United States)

    Karabegovic, Alen; Hinteregger, Markus; Janeczek, Christoph; Mohl, Werner; Gföhler, Margit

    2017-06-09

    Currently available, pneumatic-based medical devices are operated using closed-loop pulsatile or open continuous systems. Medical devices utilizing gases with a low atomic number in a continuous closed loop stream have not been documented to date. This work presents the construction of a portable helium circulation addressing the need for actuating a novel, pneumatically operated catheter pump. The design of its control system puts emphasis on the performance, safety and low running cost of the catheter pump. Static and dynamic characteristics of individual elements in the circulation are analyzed to ensure a proper operation of the system. The pneumatic circulation maximizes the working range of the drive unit inside the catheter pump while reducing the total size and noise production.Separate flow and pressure controllers position the turbine's working point into the stable region of the pressure creation element. A subsystem for rapid gas evacuation significantly decreases the duration of helium removal after a leak, reaching subatmospheric pressure in the intracorporeal catheter within several milliseconds. The system presented in the study offers an easy control of helium mass flow while ensuring stable behavior of its internal components.

  20. Evaluation of advanced turbomachinery for underground pumped hydroelectric storage. Part 3. Multistage unregulated pump/turbines for operating heads of 1000 to 1500 m

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, A.A.; Pistner, C.

    1980-08-01

    This is the final report in a series of three on studies of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. All three reports address Francis-type, reversible pump/turbines. The first report covered single-stage regulated units; the second report covered two-stage regulated units; the present report covers multistage unregulated units. Multistage unregulated pump/turbines offer an economically attractive option for heads of 1000 to 1500 m. The feasibility of developing such machines for capacities up to 500 MW and operating heads up to 1500 m has been evaluated. Preliminary designs have been generated for six multistage pump/turbines. The designs are for nominal capacities of 350 and 500 MW and for operating heads of 1000, 1250, and 1500 m. Mechanical, hydraulic, and economic analyses indicate that these machines will behave according to the criteria used to design them and that they can be built at a reasonable cost with no unsolvable problems. Efficiencies of 85.8% and 88.5% in the generating and pumping modes, respectively, can be expected for the 500-MW, 1500-m unit. Performances of the other five machines are at least comparable, and usually better. Over a 1000 to 1500-m head range, specific $/kW costs of the pump/turbines in mid-1978 US dollars vary from 19.0 to 23.1 for the 500-MW machines, and from 21.0 to 24.1 for the 350-MW machines.

  1. Operation of the counter-rotating type pump-turbine unit installed in the power stabilizing system

    Science.gov (United States)

    Kanemoto, T.; Honda, H.; Kasahara, R.; Miyaji, T.

    2014-03-01

    This serial research intends to put a unique power stabilization system with a pumped storage into practical use. The pumped storage is equipped with a counter-rotating type pump-turbine unit whose operating mode can be shifted instantaneously in response to the fluctuation of power from renewable resources. This paper verifies that the system is reasonably effective to stabilize the fluctuating power. It is necessary to quickly increase the rotational speed when the operation is shifted from the turbine to the pumping modes, because the unit cannot pump-up water from a lower reservoir at a slow rotational speed while keeping gross/geodetic head constant. The maximum hydraulic efficiency at the turbine mode is close to the efficiency of the counter-rotating type hydroelectric unit designed exclusively for the turbine mode. The system is also provided for a pilot plant to be operated in the field.

  2. Operational comparison of bubble (super heated drop) dosimetry results with routine albedo thermoluminescent dosimetry for a selected group of Pu-238 workers at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L.L.; Hoffman, J.M.; Foltyn, E.M.; Buhl, T.E.

    1999-03-01

    This paper is an operational study that compares the use of albedo thermoluminescent dosimeters with bubble dosimeters to determine whether bubble dosimeters do provide a useful daily ALARA tool that can yield measurements close to the dose-of-record. A group of workers at the Los Alamos National Laboratory (LANL) working on the Radioactive Thermoelectric Generators (RTG) for the NASA Cassini space mission wore both bubble dosimeters and albedo dosimeters over a period from 1993 through 1996. The bubble dosimeters were issued and read on a daily basis and the data were used as an ALARA tool. The personnel albedo dosimeter was processed on monthly basis and used as the dose-of-record. The results of this study indicated that cumulative bubble dosimetry results agreed with whole-body albedo dosimetry results within about 37% on average. However it was observed that there is a significant variability of the results on an individual basis both month-to-month and from one individual to another.

  3. Study and Development of an Air Conditioning System Operating on a Magnetic Heat Pump Cycle

    Science.gov (United States)

    Wang, Pao-Lien

    1991-01-01

    This report describes the design of a laboratory scale demonstration prototype of an air conditioning system operating on a magnetic heat pump cycle. Design parameters were selected through studies performed by a Kennedy Space Center (KSC) System Simulation Computer Model. The heat pump consists of a rotor turning through four magnetic fields that are created by permanent magnets. Gadolinium was selected as the working material for this demonstration prototype. The rotor was designed to be constructed of flat parallel disks of gadolinium with very little space in between. The rotor rotates in an aluminum housing. The laboratory scale demonstration prototype is designed to provide a theoretical Carnot Cycle efficiency of 62 percent and a Coefficient of Performance of 16.55.

  4. Around the laboratories: Dubna: Physics results and progress on bubble chamber techniques; Stanford (SLAC): Operation of a very rapid cycling bubble chamber; Daresbury: Photographs of visitors to the Laboratory; Argonne: Charge exchange injection tests into the ZGS in preparation for a proposed Booster

    CERN Multimedia

    1969-01-01

    Around the laboratories: Dubna: Physics results and progress on bubble chamber techniques; Stanford (SLAC): Operation of a very rapid cycling bubble chamber; Daresbury: Photographs of visitors to the Laboratory; Argonne: Charge exchange injection tests into the ZGS in preparation for a proposed Booster

  5. Operational management of progressing cavity pump; Gerenciamento do bombeio de cavidades progressivas

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Paulo Cesar Gasse de

    1999-12-01

    The main purpose of this work is to develop an intelligent system to management and control, that allows to periodically evaluate the operational performance of a petroleum field producing with the wells equipped with PCP - Progressing Cavity Pump. The work was developed in two main stages. Initially, it was accomplished a literature search about PCP, in order to identify its fundamental parameters that provide a better operation of the system. Afterwards, based on the experience obtained during the last years with the accompaniment of petroleum fields in Bahia, it is proposed a control system for management of the petroleum field operations, centered to PCP. This system uses techniques of artificial intelligence, as fuzzy sets, to obtain better interpolations. It is desired that the results presented in this Master's thesis can be useful to managers, engineers, supervisors and operators to obtain a continuous and optimized performance of this artificial lift method, at petroleum production. (author)

  6. Bubble coalescence

    NARCIS (Netherlands)

    Orvalho, Sandra; Ruzicka, Marek C.; Olivieri, Giuseppe; Marzocchella, Antonio

    2015-01-01

    The goal of this study is to present new experimental data on the effect of the bubble approach velocity and liquid viscosity on pairwise bubble coalescence. Measurements were performed to investigate the dynamics of bubble coalescence under well-defined laboratory conditions. Air and pure

  7. Hardware and software system for monitoring oil pump operation in power high-voltage transformers

    Directory of Open Access Journals (Sweden)

    Михайло Дмитрович Дяченко

    2017-07-01

    Full Text Available The article considers the basic prerequisites for the creation of an automated monitoring system for oil pumps of high-voltage transformers. This is due to the fact that the long operation of oil pumps results in deterioration and destruction of bearings, rubbing of the rotor, breakage and damage to the impeller, leakage, etc., which inevitably causes a significant decrease in the insulating properties of the transformer oil and leads to expenditures for its further recovery. False triggerings of gas protection sometimes occur. Continuous operation of the electric motor also requires additional equipment to protect the motor itself from various emergency situations, such as a short in the stator winding, a housing breakdown, an incomplete phase mode, etc. The use of stationary systems provides: diagnosing defects at an early stage of their development, increasing the reliability and longevity of the equipment components, increasing the overhaul period, decreasing the number of emergency stops, and adjusting the schedule of preventative maintenance. The basic principles of identification of the damaged part of the oil pump are given, the hardware and algorithmic solutions are considered in the work. The full-scale tests of the model sample on the power transformer of the high-voltage substation confirmed the assumption of the possibility of detecting the damaged unit separating it from the rest connected in one mechanical structure. A detailed analysis of the operation of each of the units is carried out by means of the general substation switchboard and displayed as graphs, diagrams and text messages. When the limit values of vibration are reached, faults in the operation of the unit are detected, the overlimit current values, a warning alarm is activated, and the command to disconnect the damaged unit is issued. The optimal solution for the organization of the information collection system using the principle of sensor networks, but combined

  8. Bubble pump for integrated nanofluidics

    NARCIS (Netherlands)

    Tas, Niels Roelof; Berenschot, Johan W.; Sanders, Remco G.P.; Lammerink, Theodorus S.J.; Elwenspoek, Michael Curt; van den Berg, Albert

    2001-01-01

    A new concept for liquid manipulation has been developed and implemented in surface micromachined fluid channels. It is based on the surface tension directed injection of a gas into the liquid flow through micron sized holes in the microchannel wall. The injected gas is directed to an exhaust by a

  9. Water Pump Development for the EVA PLSS

    Science.gov (United States)

    Schuller, Michael; Kurwitz, Cable; Goldman, Jeff; Morris, Kim; Trevino, Luis

    2009-01-01

    This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design, fabricate, and test a preflight prototype pump for use in the Extravehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump will accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting noncondensable gas without becoming "air locked." The chosen pump design consists of a 28 V DC, brushless, sealless, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. Although the planned flight unit will use a sensorless motor with custom designed controller, the preflight prototype to be provided for this project incorporates Hall effect sensors, allowing an interface with a readily available commercial motor controller. This design approach reduced the cost of this project and gives NASA more flexibility in future PLSS laboratory testing. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES will simulate the vacuum environment in which the flight pump will operate. Testing will verify that the pump meets design requirements for range of flow rates, pressure rise, power consumption, working fluid temperature, operating time, and restart capability. Pump testing is currently

  10. Bubble rupture in bubble electrospinning

    Directory of Open Access Journals (Sweden)

    Chen Rouxi

    2015-01-01

    Full Text Available As the distinctive properties and different applications of nanofibers, the demand of nanofibers increased sharply in recently years. Bubble electrospinning is one of the most effective and industrialized methods for nanofiber production. To optimize the set-up of bubble electrospinning and improve its mass production, the dynamic properties of un-charged and charged bubbles are studied experimentally, the growth and rupture process of a bubble are also discussed in this paper.

  11. The progressing cavity pump operating envelope : you cannot expand what you don't understand

    Energy Technology Data Exchange (ETDEWEB)

    Noonan, S.G. [ConocoPhillips Co., Houston, TX (United States)

    2008-10-15

    For years, the preferred method of lift for cold heavy oil production has been progressing cavity pumps (PCP) but their use has resulted in many misapplications and poor performance. Testing programs have since emerged to understand the science behind PCP performance under different conditions. This paper described some of the recent findings from these test programs in order to assist in selecting and designing a PCP system for heavy oil, including understanding gas handling capabilities, rod string torsion, elastomer swell, metallic stators, and the effects of speed and rotor-stator fit on PCP run life. The paper also described the efforts of a group of operating companies to standardize nomenclature and data parameters in order to facilitate analysis and benchmarking to identify areas for improvement and gaps for technology advancement. Information from a group of PCP users and manufacturers that created comprehensive international standards in 2006 and recommended practices for the manufacturing and testing of these pumping systems were also provided. It was concluded that much is still needed to be understood in understanding PCP performance, especially drive string dynamics, pump pressure capability, and PCP system reliability. 18 refs., 2 figs.

  12. The effect of maximum open height on operating characteristics of polymer injected pump poppet valve

    Science.gov (United States)

    Zhang, S. C.; Chen, X. D.; Deng, H. Y.

    2012-11-01

    Reciprocating polymer injected pump is the key injection equipment of tertiary oil recovery, the poppet valve in it exists the problem of large vibration noise, low efficiency and short life when transportation high viscosity medium. So the CFD technique is adopted to simulate and analyze the inner flow fields of fluid end poppet valve. According to the practical structure of the poppet valve, a simplified 2D axis-symmetry geometry model of the flow field is established. Combined with pump speed, plunger stroke and plunger diameter, given the boundary condition of the inlet valve, then the numerical simulation of flow field under six different maximum open heights is done depending on software Fluent. The relationship between open height to valve gap flow velocity, hydraulic loss and lag angle is obtained. The results indicate that, with the increase of open height, the valve gap flow velocity decreases, inlet outlet pressure differential decreases and hydraulic loss decreases. But the lag angle is continuously increasing with the increase of maximum open height, the valve has a good work performance when the open height is 1, 1.5, 2, 2.5, 3mm, but when it reaches 3.5mm, the valve performance becomes poor. The study can offer certain reference to understand operating characteristics of poppet valve, help to reduce the hydraulic losses and raise volume efficiency of the pump.

  13. Multiobjective Optimization of a Counterrotating Type Pump-Turbine Unit Operated at Turbine Mode

    Directory of Open Access Journals (Sweden)

    Jin-Hyuk Kim

    2014-05-01

    Full Text Available A multiobjective optimization for improving the turbine output and efficiency of a counterrotating type pump-turbine unit operated at turbine mode was carried out in this work. The blade geometry of both the runners was optimized using a hybrid multiobjective evolutionary algorithm coupled with a surrogate model. Three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model were discretized by finite volume approximations and solved on hexahedral grids to analyze the flow in the pump-turbine unit. As major hydrodynamic performance parameters, the turbine output and efficiency were selected as objective functions with two design variables related to the hub profiles of both the runner blades. These objectives were numerically assessed at twelve design points selected by Latin hypercube sampling in the design space. Response surface approximation models for the objectives were constructed based on the objective function values at the design points. A fast nondominated sorting genetic algorithm for the local search coupled with the response surface approximation models was applied to determine the global Pareto-optimal solutions. The trade-off between the two objectives was determined and described with respect to the Pareto-optimal solutions. The results of this work showed that the turbine outputs and efficiencies of optimized pump-turbine units were simultaneously improved in comparison to the reference unit.

  14. Inertial microfluidic pump

    Science.gov (United States)

    Kornilovitch, Pavel; Govyadinov, Alexander; Markel, David; Torniainen, Erik

    2015-11-01

    The inertial pump is powered by a microheater positioned near one end of a fluidic microchannel. As the microheater explosively boils the surrounding fluid, a vapor bubble expands and then collapses asymmetrically, resulting in net flow. Such devices become an effective means of transporting fluids at microscale. They have no moving parts and can be manufactured in large numbers using standard batch fabrication processes. In this presentation, physical principles behind pump operation are described, in particular the role of reservoirs in dissipating mechanical momentum and the expansion-collapse asymmetry. An effective one-dimensional dynamic model is formulated and solved. The model is compared with full three-dimensional CFD simulations and available experimental data. Potential applications of inertial micropumps are described.

  15. Evaluation of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. Part 1. Single-stage regulated pump turbines for operating heads of 500 to 1000 m

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, A.A.; Blomquist, C.A.; Degnan, J.R.

    1979-10-01

    High-head, large-capacity turbomachinery is needed for the concept of underground pumped hydroelectric storage to be technically and economically attractive. Single-stage, reversible, Francis-type pump turbines with adjustable wicket gates appear to offer the most economically attractive option for heads between about 500 and 1000 m. The feasibility of developing these types of machines for capacities up to 500 MW and operating heads up to 1000 m has been evaluated. Preliminary designs have been generated for six single-stage pump turbines. The designs are for capacities of 350 and 500 MW and for operating heads of 500, 750, and 1000 m. The report contains drawings of the machines along with material specifications and hydraulic performance data. Mechanical, hydraulic, and economic analyses indicate that these machines will behave according to the criteria used to design them and that they can be built at a reasonable cost. The stress and deflection responses of the 500-MW, 100-m-head pump turbine, determined by detailed finite element analysis techniques, give solid evidence of the integrity of the conceptual designs of the six units and indicate no unsolvable problems. Results of a life expectancy analysis of the wicket gates indicate that a near infinite life can be expected for these components when they are subjected to normal design loads. Efficiencies of 90.7 and 91.4% in the generating and pumping modes, respectively, can be expected for the 500-MW, 1000-m-head unit. Performances of the other five machines are comparable. The specific costs of the pump turbines in mid-1978 US dollars per kW vary from 19.2 to 11.8 over a head range of from 500 to 1000 m for the 500-MW machines and from 20.0 to 12.3 for the 350-MW machines.

  16. Review of Operational Challenges and Changing Conditions associated with Offshore Submerged Vertical Pumping Station

    Science.gov (United States)

    Samsudin, M. L.; Munisamy, K. M.; Thangaraju, S. K.

    2015-09-01

    Cooling water system is one of the essential auxiliary systems for a power generating plant. The decision to have an offshore pumping station, instead of onshore station, may have been driven by the scarcity in land area or for direct water supply access. However, the design has several disadvantages such as tendency for sediment intakes, limited condition monitoring activities and inaccessible sump for maintenance and modification. The paper reviews and lists several potential operational challenges and difficulties experienced with the offshore station. The influences of changing conditions such as varying seawater tide level, clogged intake screen, intake sedimentation issues and marine fouling on the sump walls and structures, are discussed and mitigating solutions are identified. While it is impractical to conduct physical model test for studying flow pattern, the CFD method can be an attractive assessment tools. In addition to this, a review of plant operating parameters can assist in identifying flow anomalies to anticipate potential deterioration. Finally the difficulty in incorporating the solutions to vortex and sediment problems within the sump is highlighted with preference for those which can be managed by limited access or those which are moveable with the vertical pump.

  17. Practical operation strategies for pumped hydroelectric energy storage (PHES) utilising electricity price arbitrage

    DEFF Research Database (Denmark)

    Connolly, David; Lund, Henrik; Finn, P.

    2011-01-01

    that almost all (not, vert, similar97%) of the profits can be obtained by a PHES facility when it is optimised using the 24Optimal strategy developed, which optimises the energy storage based on the day-ahead electricity prices. However, to maximise profits with the 24Optimal strategy, the day......In this paper, three practical operation strategies (24Optimal, 24Prognostic, and 24Hsitrocial) are compared to the optimum profit feasible for a PHES facility with a 360 MW pump, 300 MW turbine, and a 2 GWh storage utilising price arbitrage on 13 electricity spot markets. The results indicate......-ahead electricity prices must be the actual prices which the PHES facility is charged or the PHES operator must have very accurate price predictions. Otherwise, the predicted profit could be significantly reduced and even become a loss. Finally, using the 24Optimal strategy, the PHES profit can surpass the annual...

  18. Dual wavelength operation in diode-end-pumped hybrid vanadate laser

    Indian Academy of Sciences (India)

    A J Singh; S K Sharma; P K Mukhopadhyay; S M Oak

    2010-11-01

    Dual wavelength operation at 1062.8 nm and 1064.1 nm in a diode-pumped hybrid laser comprising of Nd3+-doped birefringent YVO4 and GdVO4 crystals is demon-strated. A detailed characterization of the laser is performed under CW and pulsed operation. Under Q-switching, 4 W of average power at 5 kHz repetition rate is obtained with 32 ns FWHM pulse duration corresponding to 25 kW of the peak power. The intensity and the polarization of the individual spectral components can be easily controlled by changing the relative gain and the relative orientation of the two crystals. The resulting pulsed dual-wavelength laser has the potential to be used as a source for generating terahertz radiation.

  19. Operation Performance of Air Source Heat Pump System for Space Heating in Tianjin

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun; CHEN Yan; QU Hang; LI Xinguo

    2007-01-01

    An air source heat pump system (ASHPS) used in an office building is set up and studied experimentally. Its operating performance in winter is evaluated based on test data and a comparative discussion is given on the effect of climate conditions and heating load ratio on the operation behavior.Then heating capacity variation caused by evaporator frosting is analyzed as well. Finally, the defrosting parameters and the technical feasibility are studied for a constant heating demand. The experimental results indicate that both the outlet water temperature drop and the system COP should be taken into account when setting defrosting parameters, and ASHPS is a viable technology for space heating and hotwater production in winter in Tianjin, which can maintain the room temperature above 19 ℃ when the outdoor temperature is -2 ℃.

  20. Bubble systems

    CERN Document Server

    Avdeev, Alexander A

    2016-01-01

    This monograph presents a systematic analysis of bubble system mathematics, using the mechanics of two-phase systems in non-equilibrium as the scope of analysis. The author introduces the thermodynamic foundations of bubble systems, ranging from the fundamental starting points to current research challenges. This book addresses a range of topics, including description methods of multi-phase systems, boundary and initial conditions as well as coupling requirements at the phase boundary. Moreover, it presents a detailed study of the basic problems of bubble dynamics in a liquid mass: growth (dynamically and thermally controlled), collapse, bubble pulsations, bubble rise and breakup. Special emphasis is placed on bubble dynamics in turbulent flows. The analysis results are used to write integral equations governing the rate of vapor generation (condensation) in non-equilibrium flows, thus creating a basis for solving a number of practical problems. This book is the first to present a comprehensive theory of boil...

  1. High power CW and Q-switched operation of a diode-side-pumped Nd: YAG 1319-nm laser

    Institute of Scientific and Technical Information of China (English)

    Yunfang Wan; Kezhen Han; Yun Wang; Jingliang He

    2008-01-01

    We demonstrated the highly efficient continuous wave(CW)and Q-switched infrared laser from a diodeside-pumped Nd:YAG crystal.A CW output as high as 66 W at 1319 nm was achieved under the pump power of 460 W,corresponding to a coversion efficiency of 14.3%.A maximum average power of 8.9 W of TEM00 mode was obtained in Q-switched operation at the repetition rate of 8 kHz.The performance of the laser considering the thermal lens effect induced by pump power Was also analyzed.

  2. Custom Unit Pump Development for the EVA PLSS

    Science.gov (United States)

    Schuller, Michael; Kurwitz, Cable; Little, Frank; Oinuma, Ryoji; Larsen, Ben; Goldman, Jeff; Reinis, Filip; Trevino, Luis

    2010-01-01

    This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design and test a pre-flight prototype pump for use in the Extra-vehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump must accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting non-condensable gas without becoming air locked. The chosen pump design consists of a 28 V DC, brushless, seal-less, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES verified that the pump meets the design requirements for range of flow rates, pressure drop, power consumption, working fluid temperature, operating time, gas ingestion, and restart capability under both ambient and vacuum conditions. The pump operated at 40 to 240 lbm/hr flow rate, 35 to 100 oF pump temperature, and 5 to 10 psid pressure rise. Power consumption of the pump controller at the nominal operating point in both ambient and vacuum conditions was 9.5 W, which was less than the 12 W predicted. Gas ingestion capabilities were tested by injecting 100 cc of air into the fluid line; the pump operated normally throughout this test.

  3. Thermodynamic evaluation of the possibility to increase cogeneration turbine efficiency by using a heat pump operating with steam

    Science.gov (United States)

    Batenin, V. M.; Datsenko, V. V.; Zeigarnik, Yu. A.; Kosoi, A. S.; Sinkevich, M. V.

    2016-01-01

    Cogeneration turbines operate in different operation modes that considerably differ as to the working process conditions. In summer time, when heat demand is minimal, almost all steam flow passes through all turbine stages and enters into the condenser (condensing mode of operation). When heat supply is needed, the steam bleed-offs are used. The several last stages of the turbine (low-pressure part—LPP) have a control diaphragm at the inlet. When the heat supply is large, the diaphragm is maximally closed, and the entire steam flow, with an exception for a minimal ventilation flow is delivered to the steam bleed-offs (cogeneration mode). LPP flow path is designed for the optimal operation in the condensing mode. While running in cogeneration mode, the LPP operating conditions are far from optimal. Depending on the ventilation steam flow rate and outlet pressure, the LPP power can drop to zero or even become negative (ventilation mode). It is proposed to control an outlet steam pressure by using the heat pump that operates with steam. The heat pump energy consumption can be compensated and even exceeded by optimizing the steam expansion process in LPP. In this respect, operating conditions of cogeneration turbine LPPs during the cold season are analyzed. A brief description of a heat pump operating with steam is made. The possibility of increasing cogeneration turbine efficiency by using a steam heat pump is shown.

  4. Thermodynamic analysis of a thermally operated cascade sorption heat pump for continuous cold generation

    Directory of Open Access Journals (Sweden)

    P. Muthukumar, D.V.N. Lakshmi

    2013-01-01

    Full Text Available In this paper, the thermodynamic analysis of a cascade sorption system consists of a two-stage metal hydride heat pump as topping cycle and a single-stage lithium bromide water system as bottom cycle is presented. The effects of various operating temperatures such as driving heat, heat release and refrigeration temperatures, and design parameters such as ratio of metal hydride mass to reactor mass and sensible heat exchange factor on the combined coefficient of performance (COP of the cascade cycle, and specific cooling power (SCP and total cold output of the metal hydride heat pump cycle are presented. It is observed that the combined COP is found to increase with heat release and refrigeration temperatures and however, decreases with driving heat temperature. Increase of sensible heat exchange factor improves the system performances significantly. Reduction in mass ratio from 0.5 to 0.1 improves the combined COP of the cascade system by about 10 %. The maximum predicted combined COP of the system is about 1.66 at the driving heat, heat release and refrigeration temperatures of 270 °C, 125 °C and 12°C, respectively.

  5. Thermodynamic analysis of a thermally operated cascade sorption heat pump for continuous cold generation

    Energy Technology Data Exchange (ETDEWEB)

    Muthukumar, P.; Lakshmi, D.V.N. [Department of Mechanical Engineering, Indian Institute of Technology, Guwahati – 781039 (India)

    2013-07-01

    In this paper, the thermodynamic analysis of a cascade sorption system consists of a two-stage metal hydride heat pump as topping cycle and a single-stage lithium bromide water system as bottom cycle is presented. The effects of various operating temperatures such as driving heat, heat release and refrigeration temperatures, and design parameters such as ratio of metal hydride mass to reactor mass and sensible heat exchange factor on the combined coefficient of performance (COP) of the cascade cycle, and specific cooling power (SCP) and total cold output of the metal hydride heat pump cycle are presented. It is observed that the combined COP is found to increase with heat release and refrigeration temperatures and however, decreases with driving heat temperature. Increase of sensible heat exchange factor improves the system performances significantly. Reduction in mass ratio from 0.5 to 0.1 improves the combined COP of the cascade system by about 10 %. The maximum predicted combined COP of the system is about 1.66 at the driving heat, heat release and refrigeration temperatures of 270 deg C, 125 deg C and 12deg C, respectively.

  6. Studies of high- δ (baffled) and low- δ (open) pumped divertor operation on DIII-D

    Science.gov (United States)

    Allen, S. L.; Fenstermacher, M. E.; Greenfield, C. M.; Hyatt, A. W.; Maingi, R.; Porter, G. D.; Wade, M. R.; Bozek, A. S.; Ellis, R.; Hill, D. N.; Hollerbach, M. A.; Lasnier, C. J.; Leonard, A. W.; Mahdavi, M. A.; Nilson, D. G.; Petrie, T. W.; Schaffer, M. J.; Smith, J. P.; Stambaugh, R. D.; Thomas, D. M.; Watkins, J. G.; West, W. P.; Whyte, D. G.; Wood, R. D.

    We report new experimental results with the Radiative Divertor Project-outer baffle (RDP-OB) and cryopump in both upper single-null (USN) and double-null (DN) ELMing H-mode discharges. The baffled divertor reduced the core ionization (˜2-2.5×), in reasonable agreement with predictions from UEDGE/DEGAS modeling (˜3.75×). The upper cryopump achieved density control of ne/ ngw ˜ 0.22 (line density/Greenwald density) with Zeff ˜ 2 in high- δ plasmas. The measured exhaust is comparable to the lower pump, except at lower core electron densities ( ne < 5 × 10 19 m -3). Efficient impurity exhaust was obtained with deuterium SOL flow. Preliminary experiments with DN operation has shown that the particle exhaust to the upper pump depends on the up/down magnetic balance. Preliminary experiments indicate that the DN exhaust is roughly 40-50% of the USN exhaust at ne ˜ 4 × 10 19 m -3.

  7. Evaluation of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. Part 2. Two-stage regulated pump/turbines for operating heads of 1000 to 1500 m

    Energy Technology Data Exchange (ETDEWEB)

    Blomquist, C.A.; Frigo, A.A.; Degnan, J.R.

    1979-10-01

    This UPHS report applies to Francis-type, reversible pump/turbines regulated with gating systems. The first report, however, covered single-stage regulations; this report covers two-stage regulations. Development of a two-stage regulated pump/turbine appears to be attractive because the proposed single-drop UPHS concept requires turbomachinery with a head range of 1000 to 2000 m. With turbomachinery of this range available, the single-drop scheme offers a simple and economic UPHS option. Six different two-stage, top-gated pump/turbines have been analyzed: three that generate 500 MW and three that generate 350 MW. In each capacity, one machine has an operating head of 1000 m, another has a head of 1250 m, and the third has a head of 1500 m. The rated efficiencies of the machines vary from about 90% (1000-m head) to about 88% (1500-m head). Costs in 1978 $/kW for the three 500-MW units are: 20.5 (1000 m), 16.5 (1250 m), and 13.5 (1500 m). Corresponding costs for the three 350-MW units are 23, 18, and 14 $/kW. No major turbomachinery obstacles are foreseen that could hamper development of these pump/turbines. Further model testing and development are needed before building them.

  8. Speed-variable Switched Differential Pump System for Direct Operation of Hydraulic Cylinders

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Roemer, Daniel Beck; Pedersen, Henrik Clemmensen

    2015-01-01

    proportional valves, this design allows to control the lower chamber pressure levels, throttling excess compression flow to tank. The resulting design introduces additional losses due to throttling of excess compression flow, but also improves the dynamic properties of the system significantly. The proposed...... differential cylinders. The main idea was here to utilize an electric rotary drive, with the shaft interconnected to two antiparallel fixed displacement gear pumps, to actuate a differential cylinder. With the design carried out such that the area ratio of the cylinder matches the displacement ratio of the two...... may seriously influence the dynamics and hence the performance during operation. This paper presents an analysis of these properties, and a redesign of the hydraulic system concept is proposed. Here the area- and displacement ratios are deliberately mismatched, causing inherent pressure build...

  9. Study on Operating Performance of Stirling Engine-Driven Vapor Compression Heat Pump System

    Science.gov (United States)

    Kagawa, Noboru

    Stirling engines have many unique advantages including higher thermal efficiencies, preferable exhaust gas characteristics, multi-fuel usage, and low noise and vibration. On the other hand, heat pump systems are very attractive for space heating and cooling, and industrial usage. There are several environmental merits of Stirling driven vapor compression (SDVC) systems. A design method for the SDVC, which is based on mathematical methods for Stirling and Ranking cycles, has been developed. The attractive SDVC performance using conventional and alternative refrigerants was shown. From the calculated Total Equivalent Warming Impact (TEWI) and operating costs, it became clear that the SDVC system with the alternative refrigerant has a higher potential as the future air-conditioning system.

  10. Bubble, Bubble, Toil and Trouble.

    Science.gov (United States)

    Journal of Chemical Education, 2001

    2001-01-01

    Bubbles are a fun way to introduce the concepts of surface tension, intermolecular forces, and the use of surfactants. Presents two activities in which students add chemicals to liquid dishwashing detergent with water in order to create longer lasting bubbles. (ASK)

  11. Investigations of hydraulic operating conditions of air lift pump with three types of air-water mixers

    Directory of Open Access Journals (Sweden)

    Kalenik Marek

    2015-03-01

    Full Text Available Investigations of hydraulic operating conditions of air lift pump with three types of air-water mixers. The paper presents the analysis of results of the investigations concerning the influence of various constructive solutions of the air-water mixers on hydraulic operating conditions of the air lift pump. The scope of the investigations encompassed the determination of characteristics of delivery head and delivery rate for three types of air-water mixers applied in the constructed air lift pump. Using the obtained results, the efficiency of the three types of air-water mixers applied in this air lift pump was determined. The analysis was carried out and there was checked whether the improved analytical Stenning-Martin model can be used to design air lift pumps with the air-water mixers of these types. The highest capacity in the water transport was reached by the air lift pump with the 1st type air-water mixer, the lowest one – with the 3rd type air-water mixer. The water flow in the air lift pump increases along with the rise in the air flow. The lower are the hydraulic losses generated during flow of the air flux by the air-water mixer, the higher is the air lift pump capacity. Along with the rise in the water delivery head, the capacity of the air lift pump decreases. The highest efficiency is reached by the air lift pump with the 1st type air-water mixer, the lowest – with the 3st type air-water mixer. The efficiency of the air lift pump for the three investigated types of air-water mixers decreases along with the rise in air flow rate and water delivery head. The values of submergence ratio (h/L of the delivery pipe, calculated with the use of the improved analytical Stenning-Martin model, coincide quite well with the values of h/L determined from the measurements.

  12. Efficient single-mode operation of a cladding-pumped ytterbium-doped helical-core fiber laser.

    Science.gov (United States)

    Wang, P; Cooper, L J; Sahu, J K; Clarkson, W A

    2006-01-15

    A novel approach to achieving robust single-spatial-mode operation of cladding-pumped fiber lasers with multimode cores is reported. The approach is based on the use of a fiber geometry in which the core has a helical trajectory within the inner cladding to suppress laser oscillation on higher-order modes. In a preliminary proof-of-principle study, efficient single-mode operation of a cladding-pumped ytterbium-doped helical-core fiber laser with a 30 microm diameter core and a numerical aperture of 0.087 has been demonstrated. The laser yielded 60.4 W of output at 1043 nm in a beam with M2 diode stack at 976 nm. The slope efficiency at pump powers well above threshold was approximately 84%, which compares favorably with the slope efficiencies achievable with conventional straight-core Yb-doped double-clad fiber lasers.

  13. Heat pumps

    CERN Document Server

    Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

    2013-01-01

    Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

  14. Exploring Bubbles

    Science.gov (United States)

    O'Geary, Melissa A.

    Bubbles provide an enjoyable and festive medium through which to teach many concepts within the science topics of light, color, chemistry, force, air pressure, electricity, buoyancy, floating, density, among many others. In order to determine the nature of children's engagement within a museum setting and the learning opportunities of playing with bubbles, I went to a children's interactive museum located in a metropolitan city in the Northeastern part of the United States.

  15. Antigravitating bubbles

    CERN Document Server

    Barnaveli, A T; Barnaveli, Andro; Gogberashvili, Merab

    1995-01-01

    We investigate the gravitational behavior of spherical domain walls (bubbles) arising during the phase transitions in the early Universe. In the thin-wall approximation we show the existence of the new solution of Einstein equations with negative gravitational mass of bubbles and the reversed direction of time flow on the shell. This walls exhibit gravitational repulsion just as the planar walls are assumed to do. The equilibrium radius and critical mass of such objects are found for realistic models.

  16. Dynamic analysis of V-folded cavity for TEM00 operation of end-pumped solid-state laser

    Institute of Scientific and Technical Information of China (English)

    Cunfa Li; Xiangchun Shi

    2005-01-01

    Based on graphic analysis design method of optical resonator, a simple design expression of V-folded cavity of end-pumped solid-state lasers with TEMoo operation is described, which satisfies two criterias of the resonator design. We give numerical simulation of spot size as a function of thermal focal length using this design approach whose advantages axe validated experimentally.

  17. Low threshold Nd3+:KY(WO4)2 laser operated at 1072 nm pumped by diode

    Institute of Scientific and Technical Information of China (English)

    Lang Lin; Zhenqiang Chen; Ge Zhang; Rugang Wang; Zhen Li; Jingzhao Li

    2007-01-01

    @@ The diode-pumped Nd:KYW laser operated in the free-running mode at 1072 nm is demonstrated at room temperature. The laser output power of 102.6 mW with 12.07% optical-to-optical conversion efficiency and 13.16% slope efficiency is obtained.

  18. Bubble diagnostics

    Science.gov (United States)

    Visuri, Steven R.; Mammini, Beth M.; Da Silva, Luiz B.; Celliers, Peter M.

    2003-01-01

    The present invention is intended as a means of diagnosing the presence of a gas bubble and incorporating the information into a feedback system for opto-acoustic thrombolysis. In opto-acoustic thrombolysis, pulsed laser radiation at ultrasonic frequencies is delivered intraluminally down an optical fiber and directed toward a thrombus or otherwise occluded vessel. Dissolution of the occlusion is therefore mediated through ultrasonic action of propagating pressure or shock waves. A vapor bubble in the fluid surrounding the occlusion may form as a result of laser irradiation. This vapor bubble may be used to directly disrupt the occlusion or as a means of producing a pressure wave. It is desirable to detect the formation and follow the lifetime of the vapor bubble. Knowledge of the bubble formation and lifetime yields critical information as to the maximum size of the bubble, density of the absorbed radiation, and properties of the absorbing material. This information can then be used in a feedback system to alter the irradiation conditions.

  19. Optimization of the weekly operation of a multipurpose hydroelectric development, including a pumped storage plant

    Energy Technology Data Exchange (ETDEWEB)

    Popa, R; Popa, B [Faculty of Power Engineering, University Politehnica of Bucharest, 313 Spl. Independentei, sect. 6, Bucharest, 060042 (Romania); Popa, F [Institute for Hydropower Studies and Design, 5-7 Vasile Lascar, sect. 2, Bucharest, 020491 (Romania); Zachia-Zlatea, D, E-mail: bogdan.popa@rosha.r [Hidroelectrica S.A., 3 Constantin Nacu, sect. 2, Bucharest, 020995 (Romania)

    2010-08-15

    It is presented an optimization model based on genetic algorithms for the operation of a multipurpose hydroelectric power development consisting in a pumped storage plant (PSP) with weekly operation cycle. The lower reservoir of the PSP is supplied upstream from a peak hydropower plant (HPP) with a large reservoir and supplies the own HPP which provides the required discharges towards downstream. Under these conditions, the optimum operation of the assembly consisting in 3 reservoirs and hydropower plants becomes a difficult problem if there are considered the restrictions as regards: the gradients allowed for the reservoirs filling/emptying, compliance with of a long-term policy of the upper reservoir from the hydroelectric development and of the weekly cycle for the PSP upper reservoir, correspondence between the power output/consumption in the weekly load schedule, turning to account of the water resource at maximum overall efficiencies, etc. Maximization of the net energy value (generated minus consumed) was selected as performance function of the model, considering the differentiated price of the electric energy over the week (working or weekend days, peak, half-peak or base hours). The analysis time step was required to be of 3 hours, resulting a weekly horizon of 56 steps and 168 decision variables, respectively, for the 3 HPPs of the system. These were allowed to be the flows turbined at the HPP and the number of working hydrounits at PSP, on each time step. The numerical application has considered the guiding data of Fantanele-Tarnita-Lapustesti hydroelectric development. Results of various simulations carried out proved the qualities of the proposed optimization model, which will allow its use within a decisional support program for such a development.

  20. Optimization of the weekly operation of a multipurpose hydroelectric development, including a pumped storage plant

    Science.gov (United States)

    Popa, R.; Popa, F.; Popa, B.; Zachia-Zlatea, D.

    2010-08-01

    It is presented an optimization model based on genetic algorithms for the operation of a multipurpose hydroelectric power development consisting in a pumped storage plant (PSP) with weekly operation cycle. The lower reservoir of the PSP is supplied upstream from a peak hydropower plant (HPP) with a large reservoir and supplies the own HPP which provides the required discharges towards downstream. Under these conditions, the optimum operation of the assembly consisting in 3 reservoirs and hydropower plants becomes a difficult problem if there are considered the restrictions as regards: the gradients allowed for the reservoirs filling/emptying, compliance with of a long-term policy of the upper reservoir from the hydroelectric development and of the weekly cycle for the PSP upper reservoir, correspondence between the power output/consumption in the weekly load schedule, turning to account of the water resource at maximum overall efficiencies, etc. Maximization of the net energy value (generated minus consumed) was selected as performance function of the model, considering the differentiated price of the electric energy over the week (working or weekend days, peak, half-peak or base hours). The analysis time step was required to be of 3 hours, resulting a weekly horizon of 56 steps and 168 decision variables, respectively, for the 3 HPPs of the system. These were allowed to be the flows turbined at the HPP and the number of working hydrounits at PSP, on each time step. The numerical application has considered the guiding data of Fantanele-Tarnita-Lapustesti hydroelectric development. Results of various simulations carried out proved the qualities of the proposed optimization model, which will allow its use within a decisional support program for such a development.

  1. Monetary Policy and Controlling Asset Bubbles

    OpenAIRE

    Masaya Sakuragawa

    2015-01-01

    A great concern is whether there is any means of monetary policy that works for the "leaning against the wind" policy in the bubbly economy. This paper explores the scope for monetary policy that can control bubbles within the framework of the stochastic version of overlapping-generations model with rational bubbles. The policy that raises the cost of external finance, could be identified as monetary tightening, represses the boom, but appreciate bubbles. In contrast, an open market operation...

  2. Room-temperature cw operation of an efficient miniaturized Nd:YAG laser end-pumped by a superluminescent diode

    Energy Technology Data Exchange (ETDEWEB)

    Washio, K.; Iwamoto, K.; Inoue, K.; Hino, I.; Matsumoto, S.; Saito, F.

    1976-12-01

    A miniaturized Nd:YAG laser is described, in which a 3-mm-diam x 5.4-mm-long laser rod is end-pumped by a single Al/sub x/Ga/sub 1-x/As superluminescent diode (SLD) having 20-..mu..m x 1.4-nm stripe geometry. A 4.5-mW laser power was obtained at room temperature in a 1-ms pulse operation. Emitted power from the SLD was 50 mW with 1.7% external power efficiency. When continuously pumped, a 1.5-mW laser power was obtained at room temperature. (AIP)

  3. An optically pumped 2.5 μm GeSn laser on Si operating at 110 K

    Science.gov (United States)

    Al-Kabi, Sattar; Ghetmiri, Seyed Amir; Margetis, Joe; Pham, Thach; Zhou, Yiyin; Dou, Wei; Collier, Bria; Quinde, Randy; Du, Wei; Mosleh, Aboozar; Liu, Jifeng; Sun, Greg; Soref, Richard A.; Tolle, John; Li, Baohua; Mortazavi, Mansour; Naseem, Hameed A.; Yu, Shui-Qing

    2016-10-01

    This paper reports the demonstration of optically pumped GeSn edge-emitting lasers grown on Si substrates. The whole device structures were grown by an industry standard chemical vapor deposition reactor using the low cost commercially available precursors SnCl4 and GeH4 in a single run epitaxy process. Temperature-dependent characteristics of laser-output versus pumping-laser-input showed lasing operation up to 110 K. The 10 K lasing threshold and wavelength were measured as 68 kW/cm2 and 2476 nm, respectively. Lasing characteristic temperature (T0) was extracted as 65 K.

  4. PERFORMANCE ANALYSIS OF DIFFERENT ERBIUM DOPED FIBER BASED CODIRECTIONALLY PUMPED WDMSYSTEMS OPERATING IN OPTICAL WIDE-BAND

    Directory of Open Access Journals (Sweden)

    RICKY ANTHONY

    2012-02-01

    Full Text Available In this paper, simulation studies for different types of erbium doped fiber amplifier (EDFA based codirectionally pumped systems, operating in C and L band have been analyzed for wave division multiplexing (WDM, which is in accordance with ITU standards. The natural gain and noise figure (NF for variable pump powers at 0.03W, 0.06W, 0.12W, 0.18W and 0.24W were obtained. A comparative study of these fiberamplifiers using a figure of merit (FOM, in terms of gain uniformity in the given optical band was discussed.

  5. Empirical Platform Data Analysis to Investigate how Heat Pumps Operate in Real-Life Conditions

    DEFF Research Database (Denmark)

    Carmo, Carolina; Elmegaard, Brian; Nielsen, M. P.

    2015-01-01

    Heat pumps have been widely acknowledged, by academia and industry, as highly efficient thermal energy technologies, for space heating and domestic hot water production. However, there is a lack of information about real performance in residential single family houses with active participation...... the suitability of heat pumps to support fossil-fuel free energy systems....

  6. Characterization of subvisible particle formation during the filling pump operation of a monoclonal antibody solution.

    Science.gov (United States)

    Nayak, Arpan; Colandene, James; Bradford, Victor; Perkins, Melissa

    2011-10-01

    Characterization and control of aggregate and subvisible particle formation during fill-finish process steps are important for biopharmaceutical products. The filling step is of key importance as there is no further filtration of the drug product beyond sterile filtration. Filling processes can impact product quality by introducing physical stresses such as shear, friction, and cavitation. Other detrimental factors include temperature generated in the process of filling, foaming, and contact with filling system materials, including processing aids such as silicone oil. Certain pumps may shed extrinsic particles that may lead to heterogeneous nucleation-induced aggregation. In this work, microflow imaging, size-exclusion chromatography (SEC), and turbidimetry were utilized to quantify subvisible particles, aggregation, and opalescence, respectively. The filling process was performed using several commonly used filling systems, including rotary piston pump, rolling diaphragm pump, peristaltic pump, and time-pressure filler. The rolling diaphragm pump, peristaltic pump, and time-pressure filler generated notably less protein subvisible particles than the rotary piston pump, although no change in aggregate content by SEC was observed by any pump. An extreme increase in subvisible particles was also reflected in an increase in turbidity.

  7. Influence of individual heat pumps on wind power integration – Energy system investments and operation

    DEFF Research Database (Denmark)

    Hedegaard, Karsten; Münster, Marie

    2013-01-01

    Individual heat pumps are expected to constitute a significant electricity demand in future energy systems. This demand becomes flexible if investing in complementing heat storage capabilities. In this study, we analyse how the heat pumps can influence the integration of wind power by applying...

  8. Studies of cryocooler based cryosorption pump with activated carbon panels operating at 11K

    Science.gov (United States)

    Kasthurirengan, S.; Behera, Upendra; Gangradey, Ranjana; Udgata, Swarup; Krishnamoorthy, V.

    2012-11-01

    Cryosorption pump is the only solution for pumping helium and hydrogen in fusion reactors. It is chosen because it offers highest pumping speed as well as the only suitable pump for the harsh environments in a tokamak. Towards the development of such cryosorption pumps, the optimal choice of the right activated carbon panels is essential. In order to characterize the performance of the panels with indigenously developed activated carbon, a cryocooler based cryosorption pump with scaled down sizes of panels is experimented. The results are compared with the commercial cryopanel used in a CTI cryosorption (model: Cryotorr 7) pump. The cryopanel is mounted on the cold head of the second stage GM cryocooler which cools the cryopanel down to 11K with first stage reaching about ~50K. With no heat load, cryopump gives the ultimate vacuum of 2.1E-7 mbar. The pumping speed of different gases such as nitrogen, argon, hydrogen, helium are tested both on indigenous and commercial cryopanel. These studies serve as a bench mark towards the development of better cryopanels to be cooled by liquid helium for use with tokamak.

  9. Operation control of fluids pumping in curved pipes during annular flow: a numerical evaluation

    Directory of Open Access Journals (Sweden)

    T Andrade

    2016-10-01

    Full Text Available To generate projects which provide significant volume recovery from heavy oils reservoirs and improve existing projects, is important to develop new production and transport technologies, especially in the scenario of offshore fields. The core-flow technique is one of new technologies used in heavy oil transportation. This core-flow pattern is characterized by a water pellicle that is formed close or adjacent to the inner wall of the pipe, functioning as a lubricant. The oil flows in the center of the pipe causing a reduction in longitudinal pressure drop. In this sense, this work presents a numerical study of heavy oil annular flow (core-flow assisted by computational tool ANSYS CFX® Release 12.0. It was used a three-dimensional, transient and isothermal mathematical model considered by the mixture and turbulence - models to address the water-heavy oil two-phase flow, assuming laminar flow for oil phase and turbulent flow for water phase. Results of the pressure, velocity and volume fraction distributions of the phases and the pressure drop for different operation conditions are presented and evaluated. It was observed that the oil core flowing eccentrically in the pipe and stops of the water flux considerably increases the pressure drop in the pipe after the restart of the pump.

  10. Speed-variable Switched Differential Pump System for Direct Operation of Hydraulic Cylinders

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Roemer, Daniel Beck; Pedersen, Henrik Clemmensen;

    2015-01-01

    Efforts to overcome the inherent loss of energy due to throttling in valve driven hydraulic systems are many, and various approaches have been proposed by research communities as well as the industry. Recently, a so-called speed-variable differential pump was proposed for direct drive of hydraulic...... differential cylinders. The main idea was here to utilize an electric rotary drive, with the shaft interconnected to two antiparallel fixed displacement gear pumps, to actuate a differential cylinder. With the design carried out such that the area ratio of the cylinder matches the displacement ratio of the two...... gear pumps, the throttling losses are confined to cross port leakage in the cylinder and leakage of the pumps. However, it turns out that the volumetric pump losses and the pressure dynamics of the cylinder and connecting pipes may cause pressure increase- or decrease in the cylinder chambers, which...

  11. Hemodynamic effects of peri-operative statin therapy in on-pump cardiac surgery patients

    Directory of Open Access Journals (Sweden)

    Hinz Jose

    2012-07-01

    Full Text Available Abstract Background Peri-operative statin therapy in cardiac surgery cases is reported to reduce the rate of mortality, stroke, postoperative atrial fibrillation, and systemic inflammation. Systemic inflammation could affect the hemodynamic parameters and stability. We set out to study the effect of statin therapy on perioperative hemodynamic parameters and its clinical outcome. Methods In a single center study from 2006 to 2007, peri-operative hemodynamic parameters of 478 patients, who underwent cardiac surgery with cardiopulmonary bypass, were measured. Patients were divided into those who received perioperative statin therapy (n = 276; statin group and those who did not receive statin therapy (n = 202; no-statin group. The two groups were compared together using Kolmogorov-Smirnov-Test, Fisher’s-Exact-Test, and Student’s-T-test. A p value  Results There was no significant difference in the preoperative risk factors. Onset of postoperative atrial fibrillation was not affected by statin therapy. Extended hemodynamic measurements revealed no significant difference between the two groups, apart from Systemic Vascular Resistance Index (SVRI . The no-statin group had a significantly higher SVRI (882 ± 206 vs. 1050 ± 501 dyn s/cm5/m2, p = 0.022. Inotropic support was the same in both groups and no significant difference in the mortality rate was noticed. Also, hemodynamic parameters were not affected by different types and doses of statins. Conclusions Perioperative statin therapy for patients undergoing on-pump coronary bypass grafting or valvular surgery, does not affect the hemodynamic parameters and its clinical outcome.

  12. Centrifugal pumps

    CERN Document Server

    Gülich, Johann Friedrich

    2014-01-01

    This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

  13. Bubbling Threat

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The shift of China’s monetary policy stance from "moderately loose" to "prudent" in 2011 indicates curbing inflation and asset bubbles have become the Central Government’s top priority. But is China’s bubble problem short-term or long-term? Is it only monetary or related to economic structure? Is it the cause of China’s economic imbalance or the result? And what kind of deep-rooted problems in the macro economy does it reflect? All these questions call for deep thought,said Zhang Monan,a

  14. An advanced automation system for operation of Sao Paulo pumping stations from TRANSPETRO Master Control Center - CNCO

    Energy Technology Data Exchange (ETDEWEB)

    Corcioli, Mario Sergio; Barreto, Camila Maria Benevenuto [TRANSPETRO, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Since 2000 the operations of the TRANSPETRO pumping stations in the state of Sao Paulo region began to be transferred from local control centers located at the transfer and storage terminals to the National Operational Control Center (CNCO) of TRANSPETRO, located at the headquarters of the company, in Rio de Janeiro. The proposed paper aims to presenting an overview of the automation system that was developed to enable such pumping stations to be operated from CNCO in a reliable and secure manner, focusing on tools that offer an embedded system alarms completely free of false alarms with automatic determining of the root cause, and also automatic and advanced diagnoses of problems caused by failures of hardware, human error and abnormal conditions of the process, providing the CNCO SCADA system of accurate and quality information that help operators to make decisions. The referred automation system was integrated for the first time to CNCO SCADA system in 2000, for pipeline pumps of Osvat (Sao Sebastiao - Vale do Paraiba pipeline) station at the Sao Sebastiao Terminal - northern coast of Sao Paulo region. (author)

  15. SPY: an innovative intra-operative imaging system to evaluate graft patency during off-pump coronary artery bypass grafting.

    Science.gov (United States)

    Takahashi, Masao; Ishikawa, Toshihiro; Higashidani, Koichi; Katoh, Hiroki

    2004-09-01

    Off-pump coronary artery bypass grafting (CABG) has been rapidly increased, because of its less invasiveness with low complications. However, graft patency rate highly depends on the operators' capability due to technical difficulties. The SPY system, based on the fluorescence of indocyanine green, is an innovative device that permits validation of graft patency intra-operatively. Real time images of grafts are obtained with no need for catheterization, X-rays or iodine contrast medium. High-quality images could be obtained in all 290 grafts of 72 off-pump CABG cases (mean 4.0 grafts per patient). Four anastomoses (1.4%), including two proximal and two distal, were revised because of defects detected by SPY images. In one case, the SPY system revealed no blood flow in a radial sequential graft, although transit-time flow meter measurements showed a diastolic dominant pattern. SPY images provide critical information to surgeons to detect non-patent grafts, allowing them to be revised while the patient is still on the operating table. Using the SPY system, technical failures could be completely resolved during surgery. The use of the SPY system for intra-operative graft validation during off-pump CABG may become the gold standard for surgical management in the near future.

  16. Density operator of a system pumped with polaritons: a Jaynes-Cummings-like approach

    Energy Technology Data Exchange (ETDEWEB)

    Quesada, Nicolas; RodrIguez, Boris A [Instituto de Fisica, Universidad de Antioquia, Medellin, AA 1226 Medellin (Colombia); Vinck-Posada, Herbert, E-mail: nquesada@pegasus.udea.edu.co [Departamento de Fisica, Universidad Nacional de Colombia, Ciudad Universitaria, Bogota (Colombia)

    2011-01-19

    We investigate the effects of considering two different incoherent excitation mechanisms on microcavity quantum dot systems modeled using the Jaynes-Cummings Hamiltonian. When the system is incoherently pumped with polaritons it is able to sustain a large number of photons inside the cavity with Poisson-like statistics in the stationary limit, and it also leads to a separable exciton-photon state. We also investigate the effects of both types of pumpings (excitonic and polaritonic) in the emission spectrum of the cavity. We show that the polaritonic pumping considered here is unable to modify the dynamical regimes of the system at variance with the excitonic pumping. Finally, we obtain a closed form expression for the negativity of the density matrices that the quantum master equation considered here generates.

  17. Tuning bubbly structures in microchannels.

    Science.gov (United States)

    Vuong, Sharon M; Anna, Shelley L

    2012-06-01

    Foams have many useful applications that arise from the structure and size distribution of the bubbles within them. Microfluidics allows for the rapid formation of uniform bubbles, where bubble size and volume fraction are functions of the input gas pressure, liquid flow rate, and device geometry. After formation, the microchannel confines the bubbles and determines the resulting foam structure. Bubbly structures can vary from a single row ("dripping"), to multiple rows ("alternating"), to densely packed bubbles ("bamboo" and dry foams). We show that each configuration arises in a distinct region of the operating space defined by bubble volume and volume fraction. We describe the boundaries between these regions using geometric arguments and show that the boundaries are functions of the channel aspect ratio. We compare these geometric arguments with foam structures observed in experiments using flow-focusing, T-junction, and co-flow designs to generate stable nitrogen bubbles in aqueous surfactant solution and stable droplets in oil containing dissolved surfactant. The outcome of this work is a set of design parameters that can be used to achieve desired foam structures as a function of device geometry and experimental control parameters.

  18. Leverage bubble

    Science.gov (United States)

    Yan, Wanfeng; Woodard, Ryan; Sornette, Didier

    2012-01-01

    Leverage is strongly related to liquidity in a market and lack of liquidity is considered a cause and/or consequence of the recent financial crisis. A repurchase agreement is a financial instrument where a security is sold simultaneously with an agreement to buy it back at a later date. Repurchase agreement (repo) market size is a very important element in calculating the overall leverage in a financial market. Therefore, studying the behavior of repo market size can help to understand a process that can contribute to the birth of a financial crisis. We hypothesize that herding behavior among large investors led to massive over-leveraging through the use of repos, resulting in a bubble (built up over the previous years) and subsequent crash in this market in early 2008. We use the Johansen-Ledoit-Sornette (JLS) model of rational expectation bubbles and behavioral finance to study the dynamics of the repo market that led to the crash. The JLS model qualifies a bubble by the presence of characteristic patterns in the price dynamics, called log-periodic power law (LPPL) behavior. We show that there was significant LPPL behavior in the market before that crash and that the predicted range of times predicted by the model for the end of the bubble is consistent with the observations.

  19. Heat pumps: impact of the partial load operation on the efficiency; Pompes a chaleur: impact du fonctionnement a charge partielle sur le rendement

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, J. [Climastar, 35 - Vitre (France)

    2002-10-01

    On site measurements have permitted to demonstrate the energy loss generated by the rise of rate of heat pumps. The aim of this article is to propose a method for the calculation of the effective power a heat pump with respect to the duration of the operation cycle. The effective power varies with the thermal inertia of the heat emitter, with the regulation, with the size of the pump and with its load ratio. (J.S.)

  20. 3D-CFD Design Study And Optimization Of A Centrifugal Turbo Compressor For The Operation In A Hybrid Sorption/ Compression Heat Pump Cycle

    OpenAIRE

    Eckert, Thomas; Dostal, Leo; Helm, Martin; Schweigler, Christian

    2016-01-01

    In various applications the use of sorption chillers and heat pumps is limited by the available temperature level of the driving heat source or the heat sink for export of reject heat. These constraints can be overcome by integrating an efficient high-speed transonic turbo-compressor into the internal cycle of a thermally driven water/lithium bromide absorption heat pump. The operation in a hybrid heat pump with the refrigerant water implies specific challenges for the design of the compresso...

  1. Pump characteristics and applications

    CERN Document Server

    Volk, Michael

    2013-01-01

    Providing a wealth of information on pumps and pump systems, Pump Characteristics and Applications, Third Edition details how pump equipment is selected, sized, operated, maintained, and repaired. The book identifies the key components of pumps and pump accessories, introduces the basics of pump and system hydraulics as well as more advanced hydraulic topics, and details various pump types, as well as special materials on seals, motors, variable frequency drives, and other pump-related subjects. It uses example problems throughout the text, reinforcing the practical application of the formulae

  2. Experiments on bubble generation by a hydrofoil moving beneath the water surface for reducing ship drag

    Science.gov (United States)

    Kumagai, Ichiro; Murai, Yuichi; Takahashi, Yoshiaki; Sakamaki, Haruki; Tsukahara, Takahiro; Ozaki, Tsubasa; Tasaka, Yuji; Oishi, Yoshihiko

    2014-04-01

    We have invented two types of hydrofoil bubble generator for drag reduction of ship that can reduce the energy for air bubble generation on the ship hull. Their fundamental process of air entrainment and subsequent bubble generation by the hydrofoil facility are described by a simple fluid dynamic model. We experimentally determined the critical velocity of the bubble generation and the relationship between air volume flow rate and the hydrofoil velocity. The magnitude of the negative pressure produced above the hydrofoil, which is a driving force of the air entrainment, depends on the shape of the hydrofoil, gap ratio (normalized depth of the hydrofoil), Reynolds number, Froude number, and angle of attack. Recent applications of the drag-reduction technology with air bubbles to a ship save about 10%-15% of the total energy consumption of the ship. The device works as a self-priming pump when the draft of the ship is shallow (hydrofoil depends on the flow condition around the hydrofoil, proper operation of compressors is necessary. We also show experimental results on optimization of hydrofoils to enhance the hydrofoil performance of air entrainment and air bubble generation.

  3. Potential of Demand Side Management to Reduce Carbon Dioxide Emissions Associated with the Operation of Heat Pumps

    Directory of Open Access Journals (Sweden)

    Samuel J. G. Cooper

    2013-06-01

    Full Text Available This work considers the potential reduction in the carbon dioxide emissions associated with the operation of Air Source Heat Pump which could be achieved by using demand side management. In order to achieve significant reductions in carbon dioxide emissions, it is widely envisioned that electrification of the heating sector will need to be combined with decarbonisation of the electrical supply. By influencing the times at when electric heat pumps operate such that they coincide more with electricity generation which has a low marginal carbon emissions factor, it has been suggested that these emissions could be reduced further. In order to investigate this possibility, models of the UK electrical grid based on scenarios for 2020 to 2050 have been combined with a dynamic model of an air source heat pump unit and thermal models of a population of dwellings. The performance and carbon dioxide emissions associated with the heat pumps are compared both with and without demand side management interventions intended to give preference to operation when the marginal emissions factor of the electricity being generated is low. It is found that these interventions are unlikely to be effective at achieving further reductions in emissions. A reduction of around 3% was observed in scenarios based around 2035 but in other scenarios the reduction was insignificant. In the scenarios with high wind generation (2050, the DSM scheme considered here tends to improve thermal comfort (with minimal increases in emissions rather than achieving a decrease in emissions. The reasons for this are discussed and further recommendations are made.

  4. Room temperature CW and QCW operation of Ho:CaF2 laser pumped by Tm:fiber laser

    Science.gov (United States)

    Jelínek, Michal; Cvrček, Jan; Kubeček, Václav; Zhao, Beibei; Ma, Weiwei; Jiang, Dapeng; Su, Liangbi

    2017-05-01

    Laser radiation in the wavelength range around 2 μm is required for its specific properties - it is very suitable for medical applications, remote sensing, or pumping of optical parametric oscillators to generate ultrafast pulses in the mid-IR region further exploited in nonlinear optics. Crystals as YLF, YAG, LLF, and GdVO4 doped by holmium were already investigated and found suitable for the tunable laser generation around 2.1 mμ. Only a few works are devoted to the laser operation of holmium-doped fluorides as CaF2. In this work, pulsed and continuous-wave laser operation of a modified- Bridgman-grown Ho:CaF2 active crystal at room temperature is reported. A commercial 50 W 1940 nm Tm-fiber laser was used to pump a laser oscillator based on a novel 10 mm long 0.5 at.% Ho:CaF2 active crystal placed in the Peltiercooled holder. In the pulsed regime (10 ms, 10 Hz), the laser slope efficiency of 53 % with respect to the absorbed pump power was achieved. The laser generated at the central wavelength of 2085 nm with the maximum mean output power of 365 mW corresponding to the power amplitude of 3.65 W. In the continuous wave regime, the maximum output power was 1.11 W with the slope efficiency of 41 % with respect to the absorbed pump power. To our best knowledge this is the first demonstration of this laser active material operating in the CW regime at room temperature. The tuning range over 60 nm from 2034 to 2094 nm was achieved using a birefringent filter showing the possibility to develop a mode-locked laser system generating pulses in the sub-picosecond range.

  5. Bubble Drag Reduction Requires Large Bubbles

    Science.gov (United States)

    Verschoof, Ruben A.; van der Veen, Roeland C. A.; Sun, Chao; Lohse, Detlef

    2016-09-01

    In the maritime industry, the injection of air bubbles into the turbulent boundary layer under the ship hull is seen as one of the most promising techniques to reduce the overall fuel consumption. However, the exact mechanism behind bubble drag reduction is unknown. Here we show that bubble drag reduction in turbulent flow dramatically depends on the bubble size. By adding minute concentrations (6 ppm) of the surfactant Triton X-100 into otherwise completely unchanged strongly turbulent Taylor-Couette flow containing bubbles, we dramatically reduce the drag reduction from more than 40% to about 4%, corresponding to the trivial effect of the bubbles on the density and viscosity of the liquid. The reason for this striking behavior is that the addition of surfactants prevents bubble coalescence, leading to much smaller bubbles. Our result demonstrates that bubble deformability is crucial for bubble drag reduction in turbulent flow and opens the door for an optimization of the process.

  6. Bubble drag reduction requires large bubbles

    CERN Document Server

    Verschoof, Ruben A; Sun, Chao; Lohse, Detlef

    2016-01-01

    In the maritime industry, the injection of air bubbles into the turbulent boundary layer under the ship hull is seen as one of the most promising techniques to reduce the overall fuel consumption. However, the exact mechanism behind bubble drag reduction is unknown. Here we show that bubble drag reduction in turbulent flow dramatically depends on the bubble size. By adding minute concentrations (6 ppm) of the surfactant Triton X-100 into otherwise completely unchanged strongly turbulent Taylor-Couette flow containing bubbles, we dramatically reduce the drag reduction from more than 40% to about 4%, corresponding to the trivial effect of the bubbles on the density and viscosity of the liquid. The reason for this striking behavior is that the addition of surfactants prevents bubble coalescence, leading to much smaller bubbles. Our result demonstrates that bubble deformability is crucial for bubble drag reduction in turbulent flow and opens the door for an optimization of the process.

  7. Conversion of thermal energy into electricity via a water pump operating in Stirling engine cycle

    Energy Technology Data Exchange (ETDEWEB)

    Slavin, V.S. [Institute of Thermophysics SB RAS (Russian Federation); Bakos, G.C. [Democritus University of Thrace, Department of Electrical and Computer Engineering, Laboratory of Energy Economics, 67 100 Xanthi (Greece); Finnikov, K.A. [Siberian Federal University (Russian Federation)

    2009-07-15

    In this paper, the principle of heat energy conversion via Stirling pump into electricity is considered. New scheme of Stirling pump is proposed, that differs from known ones in application of offset heater and cooler and valves controlling the motion of liquid. The mathematical model is implemented to examine the liquid flow and gas heat exchange in cylinders and regenerator. The numerical simulation of engine's working cycle is conducted for the purpose of determining the characteristic parameters of its design. A possibility of achieving high thermal efficiency at acceptable power level is shown. (author)

  8. Study of flow instability in off design operation of a multistage centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Akiha; Maeda, Manabu; Kamei, Shun; Hazama, Ryota; Sano, Takeshi; Iino, Masamichi [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Hiramatsu, Hideto; Komaki, Shutaro; Miyagawa, Kazuyoshi [Waseda University, Okubo (Japan)

    2016-02-15

    In recent years, attempts have been made to make multistage centrifugal pumps smaller in size and more efficient. However, such designs are known to cause positive-slope phenomena in the Q-H curve, especially under low-flow conditions. These phenomena, which have thus far been studied experimentally and numerically, stem from flow instability in the pump. However, their mechanisms have not yet been clarified because it depends on various parameters. In this study, we focused on diffuser rotating stall, observed in positive Q-H characteristics. This study elucidates the mechanism of positive-slope generation through experimental results and two-dimensional numerical analysis.

  9. Empirical Platform Data Analysis to Investigate how Heat Pumps Operate in Real-Life Conditions

    DEFF Research Database (Denmark)

    Carmo, Carolina; Elmegaard, Brian; Nielsen, Mads Pagh

    2015-01-01

    Heat pumps have been widely acknowledged, by academia and industry, as highly efficient thermal energy technologies, for space heating and domestic hot water production. However, there is a lack of information about real performance in residential single family houses with active participation...... heat pump configurations are considered depending on source (ground or air) and sink (radiators, floor heating and/or combined systems). This unique study intends to point out the benefits and limitations of such technologies in terms of energy efficiency and comfort delivery, as well as investigating...

  10. Mode-locked and Q-switched operation of a diode laser pumped Nd:YAG laser operating at 1.064 µm

    Science.gov (United States)

    Maker, G. T.; Keen, S. J.; Ferguson, A. I.

    1988-10-01

    We describe the performance of a mode-locked and Q-switched Nd:YAG laser operating at 1.064 μm, optically pumped by a 500 mW diode laser. The cw mode-locked system provides bandwidth-limited pulses of 55 ps duration, with a corresponding peak power of 3.3 W. When Q-switched the energy within the 100 ns pulse envelope is 10 μJ giving a peak power in the largest pulse of 7 kW. Preliminary results for operation at 1.32 μm are also reported.

  11. BEBC Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  12. Blowing bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, K.

    1999-04-01

    The article, based on a series of interviews with column flotation equipment suppliers, reviews and comments on the progress of bubble generator design. Developments mentioned include the Air/Water sparger from Cominco, the SparJet and SlamJet from CPT, the CISA sparger from Sevala CISA, Microcel flotation columns from Birtley Engineering, Flotaire column flotation cells from LMC International, and the Variable Gap Sparger from MinnovEX. 1 fig., 2 photo.

  13. Continuous-wave laser operation of diode-pumped Tm-doped Gd3Ga5O12 crystal

    Science.gov (United States)

    Wang, Yi; Lan, Jinglong; Zhou, Zhiyong; Guan, Xiaofeng; Xu, Bin; Xu, Huiying; Cai, Zhiping; Wang, Yan; Tu, Chaoyang

    2017-04-01

    We report on a diode-pumped Tm:Gd3Ga5O12 (GGG) laser at 2004 nm operated in continuous-wave mode with two-mirror linear cavity configuration. The maximum output power reaches 0.58 W with laser threshold absorbed pump power of about 0.39 W and overall slope efficiency of about 18.4%, which is believed to be the highest output power for Tm:GGG laser up to now. The Tm:GGG laser shows obvious thermally induced saturation of the output power, which indicated that power and efficiency scaling could be furtherly realized by more efficient thermal removal of the laser crystal.

  14. Serum lactate as a prognostic factor in coronary artery bypass graft operation by on pump method

    OpenAIRE

    Jabbari, Ali; Banihashem, Nadia; Alijanpour, Ebrahim; Vafaey, Hamid Reza; Alereza, Hakimeh; Rabiee, Seyed Mozafar

    2013-01-01

    Background: Lactic acidosis in cardiac surgical patients is a manifestation of systemic inflammation and excess pro-inflammatory cytokine production. This investigation was designed to integrate basic concepts about lactate acidosis with a clinically used of serum lactate in patients under coronary artery bypass surgery (CABG) by on pump method.

  15. Investigation of a diode-pumped intracavity optical parametric oscillator in pulsed and continuous wave operation

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Skettrup, Torben; Balle-Petersen, O.;

    2001-01-01

    Summary form only given. CW and pulsed compact tunable laser sources in the infrared have widespread scientific, medical and industrial applications. Such a laser source can be obtained by use of a diode-pumped intracavity optical parametric oscillator (IOPO). We report on a IOPO based on a Yb...

  16. Proceedings of the Clemson Workshop on Environmental Impacts of Pumped Storage Hydroelectric Operations

    Science.gov (United States)

    Clugston, J. P.

    1980-04-01

    The pumping of water to a high reservoir for storage during periods of low power demand, so that it can be used for the generation of electricity during peak power demand was discussed. Papers which were presented exchanged ideas and data with regard to the environmental impact of this regular interchange of water.

  17. New Pump and Treat Facility Remedial Action Work Plan for Test Area North (TAN) Final Groundwater Remediation, Operable Unit 1-07B

    Energy Technology Data Exchange (ETDEWEB)

    L. O. Nelson

    2003-09-01

    This operations and maintenance plan supports the New Pump and Treat Facility (NPTF) remedial action work plan and identifies the approach and requirements for the operations and maintenance activities specific to the final medical zone treatment remedy. The NPTF provides the treatment system necessary to remediate the medical zone portion of the OU 1-07B contaminated groundwater plume. Design and construction of the New Pump and Treat Facility is addressed in the NPTF remedial action work plan. The scope of this operation and maintenance plan includes facility operations and maintenance, remedy five-year reviews, and the final operations and maintenance report for the NPTF.

  18. LMFBR with booster pump in pumping loop

    Science.gov (United States)

    Rubinstein, H.J.

    1975-10-14

    A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation.

  19. BubbleZERO—Design, Construction and Operation of a Transportable Research Laboratory for Low Exergy Building System Evaluation in the Tropics

    Directory of Open Access Journals (Sweden)

    Arno Schlueter

    2013-09-01

    Full Text Available We present the design, construction and operation of a novel building systems laboratory, the BubbleZERO—Zero Emission Research Operation. Our objective was to design a space to evaluate the performance of Swiss-developed low exergy building systems in the tropical climate of Singapore using an integrated design approach. The method we employed for evaluation in the tropics was to design and build a test bed out of the shipping containers that transported the prototype low exergy systems from Switzerland to Singapore. This approach resulted in a novel laboratory environment containing radiant cooling panels and decentralized air supply, along with a self-shading, inflated “bubble” skin, experimental low emissivity (LowE glazing, LED lighting, wireless sensors and distributed control. The laboratory evaluates and demonstrates for the first time in Singapore an integrated high-temperature cooling system with separate demand-controlled ventilation adapted for the tropics. It is a functional lab testing system in real tropical conditions. As such, the results showing the ability to mitigate the risk of condensation by maintaining a dew point below 18 °C by the separate decentralized ventilation are significant and necessary for potential future implementation in buildings. In addition, the control system provides new proof of concept for distributed wireless sensors and control for reliable automation of the systems. These key results are presented along with the integrated design process and real-life tropical operation of the laboratory.

  20. Increasing nuclear safety and operational reliability by upgrading the charging pump mechanical sealing system

    Energy Technology Data Exchange (ETDEWEB)

    Loenhout, Gerard van [Flowserve Corporation, Etten-Leur (Netherlands); Nilsson, Peter [Flowsys Technologies AB, Moelndal (Sweden); Jehander, Magnus [Ringhals AB, Vaeroebacka (Sweden)

    2016-03-15

    For the Ringhals-2 nuclear power plant, three installed centrifugal pumps were designated to have a combined High Head Safety Injection function, as well as a Chemical Volume Control System function. The pumps were originally installed with rubber bellow type mechanical seals, which over time had demonstrated an unreliable sealing performance by displaying high leakages. In 2002, the Ringhals Maintenance engineers initiated to identify a more reliable and robust shaft sealing solution. In 2007, the project was launched and the installation of the first, new mechanical sealing solution took place in the autumn of 2011. In October 2014, these mechanical seals were dismantled and inspected. The inspection confirmed the expected reliability of the new solution.

  1. Increasing nuclear safety and operational reliability by upgrading the charging pump mechanical sealing system

    Energy Technology Data Exchange (ETDEWEB)

    Loenhout, Gerard van [Flowserve Corporation, Etten-Leur (Netherlands); Nilsson, Peter [Flowsys Technologies AB, Moelndal (Sweden); Jehander, Magnus [Ringhals AB, Vaeroebacka (Sweden)

    2016-07-01

    For the Ringhals-2 nuclear power plant, three installed centrifugal pumps were designated to have a combined High Head Safety Injection function, as well as a Chemical Volume Control System function. The pumps were originally installed with rubber bellow type mechanical seals, which over time had demonstrated an unreliable sealing performance by displaying high leakages. In 2002, the Ringhals Maintenance engineers initiated to identify a more reliable and robust shaft sealing solution. In 2007, the project was launched and the installation of the first, new mechanical sealing solution took place in the autumn of 2011. In October 2014, these mechanical seals were dismantled and inspected. The inspection confirmed the expected reliability of the new solution.

  2. Plasma Formation During Operation of a Diode Pumped Alkali Laser (DPAL) in Cs

    Science.gov (United States)

    Babaeva, Natalia Yu.; Zatsarinny, Oleg; Bartschat, Klaus; Kushner, Mark J.

    2014-10-01

    Diode pumped Alkali Lasers (DPALs) produce laser action on the resonant lines of alkali atoms. Diode lasers resonantly pump the 2P3/2 state of the alkali atom which is collisionally relaxed to the 2P3/2 state which then lases to the ground state 2S1/2. The low optical quality of high power semiconductor diode lasers is converted into high optical quality laser radiation from the alkali vapor. The Cs DPAL system using Ar/Cs/C2H6 mixtures has shown promising results. (C2H6 is the collisional relaxant.) In other studies, resonant excitation of alkali vapor by low power lasers has been used to produce highly ionized channels, initiated through associative ionization and superelastic electron heating. The issue then arises if plasma formation occurs during DPAL by similar mechanisms which would be detrimental to laser performance. In this paper, we report on results from a computational study of a DPAL using Cs vapor. The global model addresses quasi-cw pumping of the Cs(2P3/2) state by laser diodes, and includes a full accounting of the resulting electron kinetics. To enable this study, the B-spline R-matrix (BSR) with pseudostates method was employed to calculate electron impact cross sections for Cs. We found that for pump rates of many to 10 kW/cm2, plasma densities approaching 1013 cm-3 occur during laser oscillation with higher values in the absence of laser oscillation. Supported by DoD High Energy Laser Mult. Res. Initiative and NSF.

  3. Economic Viability of Pumped-Storage Power Plants Equipped with Ternary Units and Considering Hydraulic Short-Circuit Operation

    Science.gov (United States)

    Chazarra, Manuel; Pérez-Díaz, Juan I.; García-González, Javier

    2017-04-01

    This paper analyses the economic viability of pumped-storage hydropower plants equipped with ternary units and considering hydraulic short-circuit operation. The analysed plant is assumed to participate in the day-ahead energy market and in the secondary regulation service of the Spanish power system. A deterministic day-ahead energy and reserve scheduling model is used to estimate the maximum theoretical income of the plant assuming perfect information of the next day prices and the residual demand curves of the secondary regulation reserve market. Results show that the pay-back periods with and without the hydraulic short-circuit operation are significantly lower than their expected lifetime and that the pay-back periods can be reduced with the inclusion of the hydraulic short-circuit operation.

  4. Diode-pumped cw and femtosecond laser operations of a hetero-composite crystal YAG||SYS:Yb

    OpenAIRE

    Druon, Frédéric; Chenais, Sébastien; Balembois, François; Georges, Patrick; Gaume, R.; Viana, Bruno

    2005-01-01

    International audience; We report cw and femtosecond laser operations under diode pumping of a diffusion-bonding heterocomposite Yb-doped crystal: Yb3+:SrY4sSiO4d3OiY2Al5O12sYAGiSYS:Ybd. To show the advantages of this heterocomposite crystal over classical Yb:SYS crystal, we first investigate the high-power cw regime. A cw power of 4.3 W is demonstrated. The femtosecond regime is also investigated, and 1-W-average-power, 130-fs pulses at 1070 nm are produced, which represents, to our knowledg...

  5. Development of the Hybrid Operation Method of a Multi-Geothermal Heat Pump System and Absorption Chiller-Heater

    Directory of Open Access Journals (Sweden)

    Young-Ju Jung

    2015-08-01

    Full Text Available Considerable efforts have been made to reduce the energy consumption of buildings due to the energy crisis, and, the Korean government has supported the use of renewable energy through various grants. Among the possible renewable energy sources, geothermal energy can be used regardless of the outside weather. Therefore, energy consumption can be reduced considerably in summer and winter. Despite the increasing use of renewable energy, the use of renewables has not been operating appropriately. Therefore, this study examined some of the problems of the operation of renewable energy and some possible improvements. The aim of the study is to evaluate a building containing an actual installed multi-geothermal heat pump (Multi-GHP system, in terms of the energy efficiency. In addition, this study evaluated the present control system and the method of complex operation regarding existing heat sources systems and GHP systems through a simulation. The results can be regarded as the result of a hybrid operation method for the improvement of an existing operation. Therefore, the Multi-GHP system energy use of a hybrid operation condition of the Multi-GHP systems and the absorption (ABS chiller-heater system was reduced compared to the operation condition of the Multi-GHP system, and the total energy consumption of the heat source equipment was reduced. The proposed operation plan was evaluated after applying the system to a building. These results showed that the efficient operation of a Multi-GHP hybrid operation method is possible. As a result, the GHP energy use of Multi-GHP systems and the ABS chiller-heater system was reduced by 30% compared to existing operation and the total energy consumption of heat source equipment was reduced by 78%.

  6. Flow Structures Around Micro-bubbles During Subcooled Nucleate Boiling

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; PENG Xiao-Feng; David M. Christopher; WANG Bu-Xuan

    2005-01-01

    The flow structures were investigated around micro bubbles on extremely thin wires during subcooled nucleate boiling. Jet flows emanating from the bubbles were observed visually with the fluid field measurement using high-speed photography and a PIV system. The jet flows induced a strong pumping effect around a bubble. The multi-jet structure was further observed experimentally, indicating the evolution of flow structure around micro bubbles. Numerical simulations explore that the jet flows were induced by a strong Marangoni effect due to high temperature gradients near the wire. The bubble interface with multi-jet structure has abnormal temperature distribution such that the coolest parts were observed at two sides of a bubble extending into the subcooled bulk liquid rather than at the top. Evaporation and condensation on the bubble interface play important roles not only in controlling the intensity of the jet flow, but also in bringing out the multi-jet structure.

  7. Influence of Trash-Barriering on Operation of Pumping Station with Wet-Pits

    OpenAIRE

    Qiu, Baoyun; He, Shuquan; Chu, Shiji; Feng, Xiaoli

    2014-01-01

    Trash racks are set before inlet sumps of a pumping station with wet-pits in order to block trash. The flow fields before and behind the trash rack were numerically simulated and flow fields in the inlet sump were calculated using the simulated velocity distribution of the section behind the trash rack as the inlet boundary condition. Local head loss of trash-barriering increases with the increase of blockage ratio of the trash rack. When waterweeds block upper part of the trash rack, flow pa...

  8. Design and Techno-economic Analysis of Domestic Solar Bubble Pump Driven Absorption Air-conditioner%一种家用太阳能气泡泵吸收式空调的系统设计与技术经济性分析

    Institute of Scientific and Technical Information of China (English)

    谢应明; 周兴法; 舒欢; 刘道平; 刘妮

    2014-01-01

    In order to effectively solve the problems of high power consumption and noisy in traditional domestic air conditioner , a new type of domestic solar bubble pump absorption air-conditioner was developed .In this air conditioner , the lithium-bromide ab-sorption chiller was driven by solar and the traditional mechanical pump was replaced by the bubble pump .Under the design re-quirement of cooling capacity of 16.5kW and heating capacity of 18.0kW, bubble pump with inner diameter of 0.05m and im-mersed height of 0.5m, solar collector with area of 20m2 and heat storage tank with volume of 1m3 were selected by theoretical calculation.Finally, techno-economic comparison of this apparatus with traditional air-conditioner shows that the solar bubble pump absorption air conditioner has greater superiority .%为了有效解决传统家用空调的高耗电和噪声问题,开发了一种新型的家用太阳能气泡泵吸收式空调装置。该装置采用太阳能驱动溴化锂吸收式制冷机组,并以气泡泵代替传统的机械泵。在空调制冷量为16.5kW和制热量为18.0kW的设计要求下,通过理论计算选择内径为0.05m和沉浸高度为0.5m的气泡泵、集热面积为20m2太阳能集热器以及容积为1m3的蓄热水槽。最后,将该装置与普通家用空调进行技术经济比较,得出太阳能气泡泵吸收式空调有很大的优越性。

  9. Bubble-Driven Inertial Micropump

    CERN Document Server

    Torniainen, Erik D; Markel, David P; Kornilovitch, Pavel E

    2012-01-01

    The fundamental action of the bubble-driven inertial micropump is investigated. The pump has no moving parts and consists of a thermal resistor placed asymmetrically within a straight channel connecting two reservoirs. Using numerical simulations, the net flow is studied as a function of channel geometry, resistor location, vapor bubble strength, fluid viscosity, and surface tension. Two major regimes of behavior are identified: axial and non-axial. In the axial regime, the drive bubble either remains inside the channel or continues to grow axially when it reaches the reservoir. In the non-axial regime the bubble grows out of the channel and in all three dimensions while inside the reservoir. The net flow in the axial regime is parabolic with respect to the hydraulic diameter of the channel cross-section but in the non-axial regime it is not. From numerical modeling, it is determined that the net flow is maximal when the axial regime crosses over to the non-axial regime. To elucidate the basic physical princi...

  10. Fama on Bubbles

    DEFF Research Database (Denmark)

    Engsted, Tom

    2016-01-01

    While Eugene Fama has repeatedly expressed his discontent with the notion of an “irrational bubble,” he has never publicly expressed his opinion on “rational bubbles.” On empirical grounds Fama rejects bubbles by referring to the lack of reliable evidence that price declines are predictable. Howe...... component in stock market valuation ratios, consistent with a rational bubble....

  11. Slurry bubble column hydrodynamics

    Science.gov (United States)

    Rados, Novica

    Slurry bubble column reactors are presently used for a wide range of reactions in both chemical and biochemical industry. The successful design and scale up of slurry bubble column reactors require a complete understanding of multiphase fluid dynamics, i.e. phase mixing, heat and mass transport characteristics. The primary objective of this thesis is to improve presently limited understanding of the gas-liquid-solid slurry bubble column hydrodynamics. The effect of superficial gas velocity (8 to 45 cm/s), pressure (0.1 to 1.0 MPa) and solids loading (20 and 35 wt.%) on the time-averaged solids velocity and turbulent parameter profiles has been studied using Computer Automated Radioactive Particle Tracking (CARPT). To accomplish this, CARPT technique has been significantly improved for the measurements in highly attenuating systems, such as high pressure, high solids loading stainless steel slurry bubble column. At a similar set of operational conditions time-averaged gas and solids holdup profiles have been evaluated using the developed Computed Tomography (CT)/Overall gas holdup procedure. This procedure is based on the combination of the CT scans and the overall gas holdup measurements. The procedure assumes constant solids loading in the radial direction and axially invariant cross-sectionally averaged gas holdup. The obtained experimental holdup, velocity and turbulent parameters data are correlated and compared with the existing low superficial gas velocities and atmospheric pressure CARPT/CT gas-liquid and gas-liquid-solid slurry data. The obtained solids axial velocity radial profiles are compared with the predictions of the one dimensional (1-D) liquid/slurry recirculation phenomenological model. The obtained solids loading axial profiles are compared with the predictions of the Sedimentation and Dispersion Model (SDM). The overall gas holdup values, gas holdup radial profiles, solids loading axial profiles, solids axial velocity radial profiles and solids

  12. Centrifugal pump handbook

    CERN Document Server

    Pumps, Sulzer

    2010-01-01

    This long-awaited new edition is the complete reference for engineers and designers working on pump design and development or using centrifugal pumps in the field. This authoritative guide has been developed with access to the technical expertise of the leading centrifugal pump developer, Sulzer Pumps. In addition to providing the most comprehensive centrifugal pump theory and design reference with detailed material on cavitation, erosion, selection of materials, rotor vibration behavior and forces acting on pumps, the handbook also covers key pumping applications topics and operational

  13. Diode-end-pumped Tm:GdVO4 laser operating at 1818 and 1915 nm

    CSIR Research Space (South Africa)

    Esser, MJD

    2009-10-01

    Full Text Available High power operation at 1818 and 1915 nm has been demonstrated from a Tm:GdVO4 laser operating in quasi-continuous-wave mode with a maximum measured power of 8.7Wand a laser output energy of 175 mJ was observed in a 20 ms pulse at 1.9 µm...

  14. Two 175 ton geothermal chiller heat pumps for leed platinum building technology demonstration project. Operation data, data collection and marketing

    Energy Technology Data Exchange (ETDEWEB)

    Kolo, Daniel [Johnson Controls, Inc., Glendale, WI (United States)

    2016-08-15

    The activities funded by this grant helped educate and inform approximately six thousand individuals who participated in guided tours of the geothermal chiller plant at Johnson Controls Corporate Headquarters in Glendale, Wisconsin over the three year term of the project. In addition to those who took the formal tour, thousands more were exposed to hands-on learning at the self-service video kiosks located in the headquarters building and augmented reality tablet app that allowed for self-guided tours. The tours, video, and app focused on the advantages of geothermal heat pump chillers, including energy savings and environmental impact. The overall tour and collateral also demonstrated the practical application of this technology and how it can be designed into a system that includes many other sustainable technologies without sacrificing comfort or health of building occupants Among tour participants were nearly 1,000 individuals, representing 130 organizations identified as potential purchasers of geothermal heat pump chillers. In addition to these commercial clients, tours were well attended by engineering, facilities, and business trade groups. This has also been a popular tour for groups from Universities around the Midwest and K-12 schools from Wisconsin and Northern Illinois A sequence of operations was put into place to control the chillers and they have been tuned and maintained to optimize the benefit from the geothermal water loop. Data on incoming and outgoing water temperature and flow from the geothermal field was logged and sent to DOE monthly during the grant period to demonstrate energy savings.

  15. Low-Cost Control System Built Upon Consumer-Based Electronics For Supervisory Control Of A Gas-Operated Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Wetherington Jr, G Randall [ORNL; Vineyard, Edward Allan [ORNL; Mahderekal, Isaac [ORNL; Abu-Heiba, Ahmad [ORNL

    2017-06-01

    A preliminary evaluation of the performance of a consumer-based control system was conducted by the Oak Ridge National Laboratory (ORNL) and Southwest Gas as part of a cooperative research and development agreement (CRADA) authorized by the Department of Energy (DOE) (Mahderekal et al. (2013). The goal of the research was to evaluate the low-cost approach as a solution for implementing a supervisory control system for a residential gas-operated heat pump. The design incorporated two consumer-based micro-controllers; the Arduino Mega-2650 and the BeagleBone (white). Ten five-ton heat pump systems were designed, fabricated, and operationally tested in the Las Vega NV region. A robust data set was produced that allowed detailed assessment of the reliability and the operational perfromance of the newly developed control system. Experiences gained from the test provided important points of improvement for subsequent evolution of the heat pump technology.

  16. An indirectly pumped terahertz quantum cascade laser with low injection coupling strength operating above 150 K

    Science.gov (United States)

    Razavipour, S. G.; Dupont, E.; Fathololoumi, S.; Chan, C. W. I.; Lindskog, M.; Wasilewski, Z. R.; Aers, G.; Laframboise, S. R.; Wacker, A.; Hu, Q.; Ban, D.; Liu, H. C.

    2013-05-01

    We designed and demonstrated a terahertz quantum cascade laser based on indirect pump injection to the upper lasing state and phonon scattering extraction from the lower lasing state. By employing a rate equation formalism and a genetic algorithm, an optimized active region design with four-well GaAs/Al0.25Ga0.75As cascade module was obtained and epitaxially grown. A figure of merit which is defined as the ratio of modal gain versus injection current was maximized at 150 K. A fabricated device with a Au metal-metal waveguide and a top n+ GaAs contact layer lased at 2.4 THz up to 128.5 K, while another one without the top n+ GaAs lased up to 152.5 K (1.3ℏω /kB). The experimental results have been analyzed with rate equation and nonequilibrium Green's function models. A high population inversion is achieved at high temperature using a small oscillator strength of 0.28, while its combination with the low injection coupling strength of 0.85 meV results in a low current. The carefully engineered wavefunctions enhance the quantum efficiency of the device and therefore improve the output optical power even with an unusually low injection coupling strength.

  17. 对矿用离心式水泵的操作和维护分析%Analysis of Operation and Maintenance of Mining Centrifugal Pumps

    Institute of Scientific and Technical Information of China (English)

    景忠玉

    2016-01-01

    在矿井建设和生产过程中,离心式水泵承担着排水的重要任务,正确使用以及维护离心式水泵对于矿井的安全生产起着决定性作用。主要分析了离心式水泵的工作原理和工作部件,提出了一系列操作和维护的有效措施。%In the process of mine construction and production ,centrifugal water pumps play an important role in drainage ,the correct use and maintenance of centrifugal water pumps are the decisive factor .This article mainly analyzed the working principle and working parts of centrifugal pumps ,then put forward a series of effective measures for the operation and maintenance of centrifugal pumps .

  18. Preload-based starling-like control for rotary blood pumps: numerical comparison with pulsatility control and constant speed operation.

    Directory of Open Access Journals (Sweden)

    Mahdi Mansouri

    Full Text Available In this study, we evaluate a preload-based Starling-like controller for implantable rotary blood pumps (IRBPs using left ventricular end-diastolic pressure (PLVED as the feedback variable. Simulations are conducted using a validated mathematical model. The controller emulates the response of the natural left ventricle (LV to changes in PLVED. We report the performance of the preload-based Starling-like controller in comparison with our recently designed pulsatility controller and constant speed operation. In handling the transition from a baseline state to test states, which include vigorous exercise, blood loss and a major reduction in the LV contractility (LVC, the preload controller outperformed pulsatility control and constant speed operation in all three test scenarios. In exercise, preload-control achieved an increase of 54% in mean pump flow ([Formula: see text] with minimum loading on the LV, while pulsatility control achieved only a 5% increase in flow and a decrease in mean pump speed. In a hemorrhage scenario, the preload control maintained the greatest safety margin against LV suction. PLVED for the preload controller was 4.9 mmHg, compared with 0.4 mmHg for the pulsatility controller and 0.2 mmHg for the constant speed mode. This was associated with an adequate mean arterial pressure (MAP of 84 mmHg. In transition to low LVC, [Formula: see text] for preload control remained constant at 5.22 L/min with a PLVED of 8.0 mmHg. With regards to pulsatility control, [Formula: see text] fell to the nonviable level of 2.4 L/min with an associated PLVED of 16 mmHg and a MAP of 55 mmHg. Consequently, pulsatility control was deemed inferior to constant speed mode with a PLVED of 11 mmHg and a [Formula: see text] of 5.13 L/min in low LVC scenario. We conclude that pulsatility control imposes a danger to the patient in the severely reduced LVC scenario, which can be overcome by using a preload-based Starling-like control approach.

  19. The Big European Bubble Chamber

    CERN Multimedia

    1977-01-01

    The 3.70 metre Big European Bubble Chamber (BEBC), dismantled on 9 August 1984. During operation it was one of the biggest detectors in the world, producing direct visual recordings of particle tracks. 6.3 million photos of interactions were taken with the chamber in the course of its existence.

  20. High-sensitivity operation of single-beam optically pumped magnetometer in a kHz frequency range

    Science.gov (United States)

    Savukov, I.; Kim, Y. J.; Shah, V.; Boshier, M. G.

    2017-03-01

    Optically pumped magnetometers (OPM) can be used in various applications, from magnetoencephalography to magnetic resonance imaging and nuclear quadrupole resonance (NQR). OPMs provide high sensitivity and have the significant advantage of non-cryogenic operation. To date, many magnetometers have been demonstrated with sensitivity close to 1 fT, but most devices are not commercialized. Most recently, QuSpin developed a model of OPM that is low cost, high sensitivity, and convenient for users, which operates in a single-beam configuration. Here we developed a theory of single-beam (or parallel two-beam) magnetometers and showed that it is possible to achieve good sensitivity beyond their usual frequency range by tuning the magnetic field. Experimentally we have tested and optimized a QuSpin OPM for operation in the frequency range from DC to 1.7 kHz, and found that the performance was only slightly inferior despite the expected decrease due to deviation from the spin-exchange relaxation-free regime.

  1. Diode-pumped intracavity optical parametric oscillator in pulsed and continuous-wave operation

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Skettrup, Torben; Petersen, O.B.;

    2002-01-01

    An intracavity optical parametric oscillator is investigated in pulsed and continuous-wave operation. The intracavity optical parametric oscillator is based on Yb:YAG as the laser material and a periodically poled lithium niobate crystal as the nonlinear material. Tuneable idler output powers above...

  2. An HTS flux pump operated by directly driving a superconductor into flux flow region in the E- J curve

    Science.gov (United States)

    Geng, Jianzhao; Coombs, T. A.

    2016-09-01

    High-T c superconducting (HTS) flux pumps are capable of compensating the persistent current decay in HTS magnets without electrical contact. In this paper, following work on a low-T c superconducting self-switching flux pump, we propose a new HTS flux pump by directly driving a high-T c superconductor into the flux flow region in the E- J curve. The flux pump consists of a transformer which has a superconducting secondary winding shorted by an YBCO-coated conductor bridge. A high alternating current with a much higher positive peak value than the negative peak value is induced in the secondary winding. The current always drives the bridge superconductor into the flux flow region only at around its positive peak value, thus resulting in flux pumping. The proposed flux pump is much simpler than existing HTS flux pumps.

  3. Continuous-wave and Q-switched operation of a resonantly pumped Ho³⁺:KY₃F₁₀ laser.

    Science.gov (United States)

    Schellhorn, Martin; Parisi, Daniela; Eichhorn, Marc; Tonelli, Mauro

    2014-03-01

    We report continuous-wave and repetitively Q-switched operation of a resonantly pumped Ho3+:KY3F10 laser at room temperature. End pumped by a Tm3+-doped silica fiber laser operating at 1938 nm, a maximum laser power of 7.8 W was obtained at a wavelength of ∼2041  nm for 21 W of absorbed pump power, corresponding to a slope efficiency of 60.7% with respect to absorbed power. At a repetition rate of 10 kHz up to 0.78 mJ, energy per pulse was demonstrated with pulse widths of 100 ns. The beam propagation factor (M2) was measured to be <1.26 at the maximum output power.

  4. Simulations of Bubble Motion in an Oscillating Liquid

    Science.gov (United States)

    Kraynik, A. M.; Romero, L. A.; Torczynski, J. R.

    2010-11-01

    Finite-element simulations are used to investigate the motion of a gas bubble in a liquid undergoing vertical vibration. The effect of bubble compressibility is studied by comparing "compressible" bubbles that obey the ideal gas law with "incompressible" bubbles that are taken to have constant volume. Compressible bubbles exhibit a net downward motion away from the free surface that does not exist for incompressible bubbles. Net (rectified) velocities are extracted from the simulations and compared with theoretical predictions. The dependence of the rectified velocity on ambient gas pressure, bubble diameter, and bubble depth are in agreement with the theory. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. Modeling of temperature and turbidity in a natural lake and a reservoir connected by pumped-storage operations

    Science.gov (United States)

    Bonalumi, Matteo; Anselmetti, Flavio S.; Wüest, Alfred; Schmid, Martin

    2012-08-01

    Pumped-storage (PS) systems are used to store electric energy as potential energy for release during peak demand. We investigate the impacts of a planned 1000 MW PS scheme connecting Lago Bianco with Lago di Poschiavo (Switzerland) on temperature and particle mass concentration in both basins. The upper (turbid) basin is a reservoir receiving large amounts of fine particles from the partially glaciated watershed, while the lower basin is a much clearer natural lake. Stratification, temperature and particle concentrations in the two basins were simulated with and without PS for four different hydrological conditions and 27 years of meteorological forcing using the software CE-QUAL-W2. The simulations showed that the PS operations lead to an increase in temperature in both basins during most of the year. The increase is most pronounced (up to 4°C) in the upper hypolimnion of the natural lake toward the end of summer stratification and is partially due to frictional losses in the penstocks, pumps and turbines. The remainder of the warming is from intense coupling to the atmosphere while water resides in the shallower upper reservoir. These impacts are most pronounced during warm and dry years, when the upper reservoir is strongly heated and the effects are least concealed by floods. The exchange of water between the two basins relocates particles from the upper reservoir to the lower lake, where they accumulate during summer in the upper hypolimnion (10 to 20 mg L-1) but also to some extent decrease light availability in the trophic surface layer.

  6. Regulatory instrument review: Aging management of LWR cables, containment and basemat, reactor coolant pumps, and motor-operated valves

    Energy Technology Data Exchange (ETDEWEB)

    Werry, E.V.; Somasundaram, S.

    1995-09-01

    The results of Stage 2 of the Regulatory Instrument Review are presented in this volume. Selected regulatory instruments, such as the Code of Federal Regulations (CFR), US Nuclear Regulatory Commission (NRC), Regulatory Guides, and ASME Codes, were investigated to determine the extent to which these regulations apply aging management to selected safety-related components in nuclear power plants. The Regulatory Instrument Review was funded by the NRC under the Nuclear Plant Aging Research (NPAR) program. Stage 2 of the review focused on four safety-related structures and components; namely, cables, containment and basemat, reactor coolant pumps, and motor-operated valves. The review suggests that the primary-emphasis of the regulatory instruments was on the design, construction, start-up, and operation of a nuclear power plant, and that aging issues were primarily addressed after an aging-related problem was recognized. This Stage 2 review confirms the results of the prior review; (see Regulatory Instrument Review: Management of Aging of LWR Major Safety-Related Components NUREG/CR-5490. The observations indicate that the regulations generally address management of age-related degradation indirectly. Specific age-related degradation phenomena frequently are dealt with in bulletins and notices or through generic issues, letters, etc. The major recommendation of this report, therefore, is that the regulatory instruments should more directly and explicitly address the aging phenomenon and the management of the age-related degradation process.

  7. Channel electron multiplier operated on a sounding rocket without a cryogenic vacuum pump from 120 to 80 km altitude

    Science.gov (United States)

    Dickson, Shannon; Gausa, Michael; Robertson, Scott; Sternovsky, Zoltan

    2013-04-01

    We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 80 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on two sounding rockets to the mesosphere. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void behind (relative to the direction of motion) an aft-facing surface. An enclosure containing the CEM was placed forward of an aft-facing deck and a valve was opened during flight to expose the CEM to the aerodynamically evacuated region behind it. The CEM operated successfully from apogee down to ∼80 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.

  8. Channel electron multiplier operated on a sounding rocket without a cryogenic vacuum pump from 120 - 75 km altitude

    Science.gov (United States)

    Dickson, S.; Gausa, M. A.; Robertson, S. H.; Sternovsky, Z.

    2012-12-01

    We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 75 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on the two sounding rockets of the CHAMPS (CHarge And mass of Meteoritic smoke ParticleS) rocket campaign which were launched into the mesosphere in October 2011 from Andøya Rocket Range, Norway. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void beneath an aft-facing surface. An enclosure containing the CEM was placed above an aft-facing deck and a valve was opened on the downleg to expose the CEM to the aerodynamically evacuated region below. The CEM operated successfully from apogee down to ~75 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.

  9. Hydraulic connection and penstock chambers in the PSP Kops II. Direct crossing from pump- into turbine operation; Hydraulischer Kurzschluss und Druckluftwasserschlosskammern im PSW Kops II. Nahtloser Uebergang vom Pump- in den Turbinenbetrieb

    Energy Technology Data Exchange (ETDEWEB)

    Puerer, E. [Vorarlberger Illwerke AG (VIW), Schruns (Austria)

    2007-04-16

    After a two years' design development phase including the implementation of the approval process and the award of contracts for all major components, the new building of Kopswerk II has been started on the 1st of September 2004. Kopswerk II is a pump storage scheme with an installed capacity of 450 to 510 MW in turbine mode and 450 MW in pumping operation. The conception of this power plant was substantially determined by the modified market conditions since the liberalization of the electricity market. Nowadays the plant is in the third year of construction. The installation of the first turbogenerator unit has advanced and will start-up in at the end of the year 2007. The completion of the total plant with full operation of the three turbogenerator units is planned in the middle of 2008. The erection cost at the end of construction shall be about 370 Mio Euro. (GL)

  10. Operational control and diagnostics of the equipment by the parameters of the electric drive power supply by the example of deep well pump units

    Science.gov (United States)

    Shishlyannikov, D. I.; Vasilyeva, M. A.

    2017-02-01

    Currently, the vast majority of Russian oil wells use oil well pumping units (OPU), equipped with a mechanical drive - a balancing pumping unit. The significant lifetime of balancing pumping units used in oil fields of Russia amounts to full or close to full resource generation and to a high accident rate of the mechanical drive rod of OPU. Reduced material costs for operation and maintenance of OPU may be provided by the rejection of the system of preventive maintenance and service during the transition to the actual technical condition. The article analyzes the statistics of the most frequent crash balancing pumping units of OPU and their causes. The prospect of applying the method of instrument control parameters is proved, and the technical condition of the OPU is assessed based on the analysis of the magnitude and the nature of changes in load drive motors, determined by the recording of the instantaneous values of power consumption. The authors consider the construction and operation of the programmable controller ‘AKD-SK’ manufactured by JSC R&D company ‘ROS’ (Perm). Fundamentals of vattmetrogramm analysis of OPU drive motors are stated, and the character of displaying key defects of submersible pumps and balanced beam unit is described.

  11. Simulation of the Operating Performance for Supplementing-compressing Heat-pump%补气增焓热泵机组运行性能模拟研究

    Institute of Scientific and Technical Information of China (English)

    李艳; 王强

    2011-01-01

    Based on the operating characteristics of air-source-heat-pump in low temperatures, a single-stage air source heat pump and a supplementing-compressing air source heat pump was simulated and calculated. A calculation of heat pump with a process of refilling was presented and the most appropriate pressures in different evaporation temperatures were obtained, which would do a lot of help to improving the operating performance of air-source-heat-pump in low temperatures.%基于空气源热泵机组在低温工况下的运行特性,对单级空气源热泵机组及补气增焓热泵机组进行仿真模拟计算,提出一种带补气的热泵机组运行性能的计算方法,得出不同蒸发温度下最佳补气压力值,对改善低温环境下空气源热泵机组的运行性能具有重要意义。

  12. Particle-bubble aggregate stability on static bubble generated by single nozzle on flotation process

    Science.gov (United States)

    Warjito, Harinaldi, Setyantono, Manus; Siregar, Sahala D.

    2016-06-01

    There are three sub-processes on flotation. These processes are intervening liquid film into critical thickness, rupture of liquid film forming three phase contact line, and expansion three phase contact line forming aggregate stability. Aggregate stability factor contribute to determine flotation efficiency. Aggregate stability has some important factors such as reagent and particle geometry. This research focussed on to understand effect of particle geometry to aggregate stability. Experimental setup consists of 9 x 9 x26 cm flotation column made of glass, bubble generator, particle feeding system, and high speed video camera. Bubble generator made from single nozzle with 0.3 mm diameter attached to programmable syringe pump. Particle feeding system made of pipette. Particle used in this research is taken from open pit Grasberg in Timika, Papua. Particle has sub-angular geometry and its size varies from 38 to 300 µm. Bubble-particle interaction are recorded using high speed video camera. Recordings from high speed video camera analyzed using image processing software. Experiment result shows that aggregate particle-bubble and induction time depends on particle size. Small particle (38-106 µm) has long induction time and able to rupture liquid film and also forming three phase contact line. Big particle (150-300 µm) has short induction time, so it unable to attach with bubble easily. This phenomenon is caused by apparent gravity work on particle-bubble interaction. Apparent gravity worked during particle sliding on bubble surface experience increase and reached its maximum magnitude at bubble equator. After particle passed bubble equator, apparent gravity force experience decrease. In conclusion particle size from 38-300 µm can form stable aggregate if particle attached with bubble in certain condition.

  13. Brut: Automatic bubble classifier

    Science.gov (United States)

    Beaumont, Christopher; Goodman, Alyssa; Williams, Jonathan; Kendrew, Sarah; Simpson, Robert

    2014-07-01

    Brut, written in Python, identifies bubbles in infrared images of the Galactic midplane; it uses a database of known bubbles from the Milky Way Project and Spitzer images to build an automatic bubble classifier. The classifier is based on the Random Forest algorithm, and uses the WiseRF implementation of this algorithm.

  14. Fama on bubbles

    DEFF Research Database (Denmark)

    Engsted, Tom

    Eugene Fama has repeatedly expressed his discontent with the notion of an irrational bubble. However, he has never publicly expressed his opinion on rational bubbles. This is peculiar since such bubbles build naturally from the rational efficient markets paradigm that Fama strongly adheres to...

  15. An Integrated Approach on Groundwater Flow and Heat/Solute Transport for Sustainable Groundwater Source Heat Pump (GWHP) System Operation

    Science.gov (United States)

    Park, D. K.; Bae, G. O.; Joun, W.; Park, B. H.; Park, J.; Park, I.; Lee, K. K.

    2015-12-01

    The GWHP system uses a stable temperature of groundwater for cooling and heating in buildings and thus has been known as one of the most energy-saving and cost-efficient renewable energy techniques. A GWHP facility was installed at an island located at the confluence of North Han and South Han rivers, Korea. Because of well-developed alluvium, the aquifer is suitable for application of this system, extracting and injecting a large amount of groundwater. However, the numerical experiments under various operational conditions showed that it could be vulnerable to thermal interference due to the highly permeable gravel layer, as a preferential path of thermal plume migration, and limited space for well installation. Thus, regional groundwater flow must be an important factor of consideration for the efficient operation under these conditions but was found to be not simple in this site. While the groundwater level in this site totally depends on the river stage control of Paldang dam, the direction and velocity of the regional groundwater flow, observed using the colloidal borescope, have been changed hour by hour with the combined flows of both the rivers. During the pumping and injection tests, the water discharges in Cheongpyeong dam affected their respective results. Moreover, the measured NO3-N concentrations might imply the effect of agricultural activities around the facility on the groundwater quality along the regional flow. It is obvious that the extraction and injection of groundwater during the facility operation will affect the fate of the agricultural contaminants. Particularly, the gravel layer must also be a main path for contaminant migration. The simulations for contaminant transport during the facility operation showed that the operation strategy for only thermal efficiency could be unsafe and unstable in respect of groundwater quality. All these results concluded that the integrated approach on groundwater flow and heat/solute transport is necessary

  16. Pumping machinery theory and practice

    CERN Document Server

    Badr, Hassan M

    2014-01-01

    Pumping Machinery Theory and Practice comprehensively covers the theoretical foundation and applications of pumping machinery. Key features: Covers characteristics of centrifugal pumps, axial flow pumps and displacement pumpsConsiders pumping machinery performance and operational-type problemsCovers advanced topics in pumping machinery including multiphase flow principles, and two and three-phase flow pumping systemsCovers different methods of flow rate control and relevance to machine efficiency and energy consumptionCovers different methods of flow rate control and relevance to machine effi

  17. PICO Bubble Chambers for Dark Matter Searches: Future Prospects

    Science.gov (United States)

    Neilson, Russell; PICO Collaboration

    2017-01-01

    The PICO collaboration uses bubble chambers to search for WIMP dark matter particles. The bubble chambers are operated in a moderately superheated state, providing superb rejection of the dominant gamma background, and are filled with fluorinated target fluids ideally suited for investigating spin-dependent WIMP-proton interactions. PICO currently operates a 2-liter (PICO-2L) and a 32-liter (PICO-60) bubble chamber at the SNOLAB deep underground laboratory. I will discuss recent activities by the PICO collaboration to understand and mitigate an anomalous background that has impacted previous dark matter searches, plans for the operating experiments, and prospects for a future ton-scale PICO bubble chamber.

  18. Operation history of hydraulic jet pump on teh Chengbei oil field, China. Chengbei yuden ni okeru haidororikku jet pump no shiyo jisseki

    Energy Technology Data Exchange (ETDEWEB)

    Terao, Yoshihiro; Takagi, Sunao

    1989-11-01

    Changbei oil field in China uses hydraulic jet pump(HJP) to cope with the increase of oil production and increase of water content in the oil field. This paper described the practical result. This pump makes high speed jet by driving fluid, and converts the dynamic energy to pressure energy by decelerating with a diffuser to push up oil. Wellheads damaged by sand friction or near the gas cap were removed. The production from March, 1988 to October increased at the rate of 114kl/day at total 8 wellheads. Heavy oil of API specific gravity of 16 degree could be proved. Since the separation of oil and water was inferior, so that the countermeasures were studied but the cause was not known. Troubles or failures of main body, nozzle and throat of HJP were not occurred. Any effect could not be found at a wellhead of water content exceeding 50 to 60% because only water production increased. Consequently, this process could result the increase of oil production with lower cost and without mechanical failures. 2 refs., 7 figs., 7 tabs.

  19. Performance Evaluation of Underwater Wireless Optical Communications Links in the Presence of Different Air Bubble Populations

    KAUST Repository

    Oubei, Hassan M.

    2017-03-16

    We experimentally evaluate the performance of underwater wireless optical communication (UWOC) links in the presence of different air bubbles. Air bubbles of different sizes and densities are generated by using an air pipe in conjunction with a submersible water pump of variable flow rate that help break up large bubbles into smaller bubbles. Received signal intensity measurements show that bubbles significantly degrade the performance of UWOC links. Large bubbles completely obstruct the optical beam and cause a deep fade. However, as the bubble size decreases, the level of deep fade also decreases because the optical beam is less susceptible to complete obstruction and more light reaches the detector. We also show that beam expansion could help mitigate the performance degradation due to the deep fade caused by air bubbles scatters in the channel.

  20. Use of optical probes to characterize bubble behavior in gas-solid fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Mainland, M.E.; Welty, J.R. (Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering)

    1995-02-01

    Optical probes are used to study gas-solid fluidized-bed hydrodynamics. The probes each consisting of a light source and photodetector separated by a gap are suitable for use at combustion-level temperatures. The methodology to process the signal for calculation of bubble properties such as bubble frequency, local bubble residence time, bubble velocity, pierced length, bubble size, and visible bubble flow is presented. The signal processing technique is independent of bed operating conditions. The probe signal processing methodology is validated by comparing calculated bubble properties based on the probe signal with properties observed on videotapes of a 2-D bed.

  1. New Pump and Treat Facility Remedial Action Work Plan For Test Area North Final Groundwater Remediation, Operable Unit 1-07B

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, L. O.

    2007-06-12

    This remedial action work plan identifies the approach and requirements for implementing the medial zone remedial action for Test Area North, Operable Unit 1-07B, at the Idaho National Laboratory. This plan details the management approach for the construction and operation of the New Pump and Treat Facility (NPTF). As identified in the remediatial design/remedial action scope of work, a separate remedial design/remedial action work plan will be prepared for each remedial component of the Operable Unit 1-07B remedial action.

  2. Test bench for operational investigation of photovoltaic pumping systems; Bancada de ensaio para averiguacao operacional de sistemas fotovoltaicos de bombeamento

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Alaan Ubaiara; Fedrizzi, Maria Cristina; Zilles, Roberto [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia], Emails: alaan@iee.usp.br, fedrizzi@iee.usp.br, zilles@iee.usp.br

    2006-07-01

    From the daily water demand, total head and the daily average irradiation, is possible to determine the size of the PV generator for pumping systems. However, once the equipment is acquired some tests are recommended, specially to verify its performance. One of the most relevant parameters to qualify a pumping system is the daily water delivered (m{sup 3}/day) as a function of daily solar irradiation (Wh/m{sup 2}). Facilities that fit different boundaries conditions, as for example constant total head (m) are not easily available, and just few laboratories have this capability. In this way a simple instrumentation with the capability to determine the daily performance of PV pumping systems is presented. The proposed test tools use a hydraulic circuit with two pumps, one connected to the PV system and the other to the electric grid. The total head is maintained constant by the variable speed drive connected to the grid. (author)

  3. IgG particle formation during filling pump operation: a case study of heterogeneous nucleation on stainless steel nanoparticles.

    Science.gov (United States)

    Tyagi, Anil K; Randolph, Theodore W; Dong, Aichun; Maloney, Kevin M; Hitscherich, Carl; Carpenter, John F

    2009-01-01

    This study investigated factors associated with vial filling with a positive displacement piston pump leading to formation of protein particles in a formulation of an IgG. We hypothesized that nanoparticles shed from the pump's solution-contact surfaces nucleated protein aggregation and particle formation. Vials of IgG formulation filled at a clinical manufacturing site contained a few visible particles and about 100,000 particles (1.5-3 microm) per mL. In laboratory studies with the same model (National Instruments FUS-10) of pump, pumping of 20 mg/mL IgG formulation resulted in about 300,000 particles (1.5-3 microm) per mL. Pumping of protein-free formulation resulted in 13,000 particles (1.5-15 microm) per mL. More than 99% of the particles were 0.25-0.95 microm in size. Mixing of protein-free pumped solution with an equal volume of 40 mg/mL IgG resulted in 300,000 particles (1.5-15 microm) per mL. Also, mixing IgG formulation with 30,000/mL stainless steel nanoparticles resulted in formation of 30,000 protein microparticles (1.5-15 microm) per mL. Infrared spectroscopy showed that secondary structure of IgG in microparticles formed by pumping or mixing with steel nanoparticles was minimally perturbed. Our results document that nanoparticles of foreign materials shed by pumps can serve as heterogeneous nuclei for formation of protein microparticles.

  4. Tribonucleation of bubbles

    CERN Document Server

    Wildeman, Sander; Sun, Chao; Lohse, Detlef; Prosperetti, Andrea

    2016-01-01

    We report on the nucleation of bubbles on solids that are gently rubbed against each other in a liquid. The phenomenon is found to depend strongly on the material and roughness of the solid surfaces. For a given surface, temperature, and gas content, a trail of growing bubbles is observed if the rubbing force and velocity exceed a certain threshold. Direct observation through a transparent solid shows that each bubble in the trail results from the early coalescence of several microscopic bubbles, themselves detaching from microscopic gas pockets forming between the solids. From a detailed study of the wear tracks, with atomic force and scanning electron microscopy imaging, we conclude that these microscopic gas pockets originate from a local fracturing of the surface asperities, possibly enhanced by chemical reactions at the freshly created surfaces. Our findings will be useful either for preventing undesired bubble formation or, on the contrary, for "writing with bubbles," i.e., creating controlled patterns ...

  5. Effects of Crust Ingestion on Mixer Pump Performance in Tank 241-SY-101: Workshop Results

    Energy Technology Data Exchange (ETDEWEB)

    Brennen, C.E.; Stewart, C.W.; Meyer, P.A.

    1999-10-20

    In August 1999, a workshop was held at Pacific Northwest National Laboratory to discuss the effects of crust ingestion on mixer pump performance in Hanford Waste Tank 241-SY-101. The main purpose of the workshop was to evaluate the potential for crust ingestion to degrade mixing and/or damage the mixer pump. The need for a previously determined 12-inch separation between the top of the mixer pump inlet and the crust base was evaluated. Participants included a representative from the pump manufacturer, an internationally known expert in centrifugal pump theory, Hanford scientists and engineers, and operational specialists representing relevant fields of expertise. The workshop focused on developing an understanding of the pump design, addressing the physics of entrainment of solids and gases into the pump, and assessing the effects of solids and gases on pump performance. The major conclusions are summarized as follows: (1) Entrainment of a moderate amount of solids or gas from the crust should not damage the pump or reduce its lifetime, though mixing effectiveness will be somewhat reduced. (2) Air binding should not damage the pump. Vibrations due to ingestion of gas, solids, and objects potentially could cause radial loads that might reduce the lifetime of bearings and seals. However, significant damage would require extreme conditions not associated with the small bubbles, fine solids, and chunks of relatively weak material typical of the crust. (3) The inlet duct extension opening, 235 inches from the tank bottom, should be considered the pump inlet, not the small gap at 262 inches. (4) A suction vortex exists at the inlet of all pumps. The characteristics of the inlet suction vortex in the mixer pump are very hard to predict, but its effects likely extend upward several feet. Because of this, the current 12-inch limit should be replaced with criteria based on actual monitored pump performance. The most obvious criterion (in addition to current operational

  6. Bubbles and market crashes

    CERN Document Server

    Youssefmir, M; Hogg, T; Youssefmir, Michael; Huberman, Bernardo; Hogg, Tad

    1994-01-01

    We present a dynamical theory of asset price bubbles that exhibits the appearance of bubbles and their subsequent crashes. We show that when speculative trends dominate over fundamental beliefs, bubbles form, leading to the growth of asset prices away from their fundamental value. This growth makes the system increasingly susceptible to any exogenous shock, thus eventually precipitating a crash. We also present computer experiments which in their aggregate behavior confirm the predictions of the theory.

  7. Bubble-sweeping mechanisms

    Institute of Scientific and Technical Information of China (English)

    WANG; Hao; (王; 昊); PENG; Xiaofeng; (彭晓峰); WANG; Buxuan; (王补宣); LEE; Duzhong; (李笃中)

    2003-01-01

    A series of subcooled boiling experiments was conducted on very small platinum wires having diameters of 0.1 and 0.025 mm. Vapor bubbles were visually observed to sweep back and forth along the wires in the experiments. The dynamic characteristics of bubble-sweeping phenomenon are described, and the induced bubble interaction and nonlinear growth are investigated to understand the boiling heat transfer mechanisms. An unsymmetrical temperature model is proposed to explain the physical mechanism.

  8. Efficient stable simultaneous CW dual-wavelength diode-end-pumped Nd :YAG laser operating at 1.319 and 1.338 μm

    Institute of Scientific and Technical Information of China (English)

    Rui Zhou; Wuqi Wen; Zhiqiang Cai; Xin Ding; Peng Wang; Jianquan Yao

    2005-01-01

    An efficient, stable diode-end-pumped simultaneous continuous-wave (CW) dual-wavelength laser operating at 1.319 and 1.338 μm in a Nd:YAG crystal has been demonstrated. A total output power of 6.3 W is achieved at an absorbed pump power of 15 W, with a slope efficiency of 43.5%. The instability of output power is less than 1%. With a type Ⅱ critical phase-matched KTP crystal inserted into the cavity as frequency doubler, a maximum output power of 200 mW in red region is acquired. In addition, a sixwavelength laser operation at 1.319 μm, 1.338 μm, 1.356 μm, 659.5 nm, 669 nm, and 678 nm is observed.

  9. Bubble and drop interfaces

    CERN Document Server

    Miller

    2011-01-01

    The book aims at describing the most important experimental methods for characterizing liquid interfaces, such as drop profile analysis, bubble pressure and drop volume tensiometry, capillary pressure technique, and oscillating drops and bubbles. Besides the details of experimental set ups, also the underlying theoretical basis is presented in detail. In addition, a number of applications based on drops and bubbles is discussed, such as rising bubbles and the very complex process of flotation. Also wetting, characterized by the dynamics of advancing contact angles is discussed critically. Spec

  10. Physics of bubble oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Lauterborn, Werner; Kurz, Thomas [Third Physical Institute, University of Goettingen (Germany)

    2010-10-01

    Bubbles in liquids, soft and squeezy objects made of gas and vapour, yet so strong as to destroy any material and so mysterious as at times turning into tiny light bulbs, are the topic of the present report. Bubbles respond to pressure forces and reveal their full potential when periodically driven by sound waves. The basic equations for nonlinear bubble oscillation in sound fields are given, together with a survey of typical solutions. A bubble in a liquid can be considered as a representative example from nonlinear dynamical systems theory with its resonances, multiple attractors with their basins, bifurcations to chaos and not yet fully describable behaviour due to infinite complexity. Three stability conditions are treated for stable trapping of bubbles in standing sound fields: positional, spherical and diffusional stability. Chemical reactions may become important in that respect, when reacting gases fill the bubble, but the chemistry of bubbles is just touched upon and is beyond the scope of the present report. Bubble collapse, the runaway shrinking of a bubble, is presented in its current state of knowledge. Pressures and temperatures that are reached at this occasion are discussed, as well as the light emission in the form of short flashes. Aspherical bubble collapse, as for instance enforced by boundaries nearby, mitigates most of the phenomena encountered in spherical collapse, but introduces a new effect: jet formation, the self-piercing of a bubble with a high velocity liquid jet. Examples of this phenomenon are given from light induced bubbles. Two oscillating bubbles attract or repel each other, depending on their oscillations and their distance. Upon approaching, attraction may change to repulsion and vice versa. When being close, they also shoot self-piercing jets at each other. Systems of bubbles are treated as they appear after shock wave passage through a liquid and with their branched filaments that they attain in standing sound fields. The N-bubble

  11. Continuous-wave and Q-switched operation of a compact, diode-pumped Yb3+:KY(WO4)2 planar waveguide laser.

    Science.gov (United States)

    Bain, F M; Lagatsky, A A; Kurilchick, S V; Kisel, V E; Guretsky, S A; Luginets, A M; Kalanda, N A; Kolesova, I M; Kuleshov, N V; Sibbett, W; Brown, C T A

    2009-02-02

    A diode-pumped LPE-grown Yb:KYW planar waveguide laser is demonstrated in a microchip monolithic cavity configuration. Output powers as high as 148 mW and thresholds as low as 40 mW were demonstrated during continuous-wave operation. Pulses of 170 ns duration with maximum pulse energy of 44 nJ at a 722 kHz repetition rate were generated when Q-switched using a semiconductor saturable absorber mirror.

  12. A safety assessment for proposed pump mixing operations to mitigate episodic gas releases in tank 241-SY-101: Hanford Site,Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Lentsch, J.W.

    1996-07-01

    This safety assessment addresses each of the elements required for the proposed action to remove a slurry distributor and to install, operate, and remove a mixing pump in Tank 241-SY-101,which is located within the Hanford Site, Richland, Washington.The proposed action is required as part of an ongoing evaluation of various mitigation concepts developed to eliminate episodic gas releases that result in hydrogen concentrations in the tank dome space that exceed the lower flammability limit.

  13. Safety assessment for proposed pump mixing operations to mitigate episodic gas releases in tank 241-101-SY: Hanford Site, Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Lentsch, J.W., Westinghouse Hanford

    1996-05-16

    This safety assessment addresses each of the elements required for the proposed action to remove a slurry distributor and to install, operate, and remove a mixing pump in Tank 241-SY-101, which is located within the Hanford Site, Richland, Washington. The proposed action is required as part of an ongoing evaluation of various mitigation concepts developed to eliminate episodic gas releases that result in hydrogen concentrations in the tank dome space that exceed the lower flammability limit.

  14. Custom Unit Pump Design and Testing for the EVA PLSS

    Science.gov (United States)

    Schuller, Michael; Kurwitz, Cable; Goldman, Jeff; Morris, Kim; Trevino, Luis

    2009-01-01

    This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design and test a pre-flight prototype pump for use in the Extra-vehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump must accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting non-condensable gas without becoming air locked. The chosen pump design consists of a 28 V DC, brushless, sealless, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. Although the planned flight unit will use a sensorless motor with custom designed controller, the pre-flight prototype to be provided for this project incorporates Hall effect sensors, allowing an interface with a readily available commercial motor controller. This design approach reduced the cost of this project and gives NASA more flexibility in future PLSS laboratory testing. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES verified that the pump meets the design requirements for range of flow rates, pressure drop, power consumption, working fluid temperature, operating time, gas ingestion , and restart capability under both ambient and vacuum conditions. The pump operated between 40 and 240 lbm/hr flowrate, 35 to 100 F

  15. Condensation-Induced Steam Bubble Collapse in a Pipeline

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Steam bubbles often occur in pipelines due to the pipeline structure or operational errors. The water hammer force induced by the steam bubble collapse is a hidden safety concern. This paper experimentally and numerically investigates the conditions for steam bubble formation and collapse. A series of video pictures taken in the laboratory show that steam bubbles form and collapse over several cycles. The pressure history of the steam bubbles is measured in conjunction with the pictures. In the experiment, the liquid column cavitated at the low pressures and then the cavities collapsed due to condensation causing high pressure pulses. The process was also simulated numerically. The results suggest that coolant pipeline design and operation must include procedures to avoid steam bubble formation.

  16. Detection of pump degradation

    Energy Technology Data Exchange (ETDEWEB)

    Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  17. Prospects for bubble fusion

    Energy Technology Data Exchange (ETDEWEB)

    Nigmatulin, R.I. [Tyumen Institute of Mechanics of Multiphase Systems (TIMMS), Marx (Russian Federation); Lahey, R.T. Jr. [Rensselaer Polytechnic Institute, Troy, NY (United States)

    1995-09-01

    In this paper a new method for the realization of fusion energy is presented. This method is based on the superhigh compression of a gas bubble (deuterium or deuterium/thritium) in heavy water or another liquid. The superhigh compression of a gas bubble in a liquid is achieved through forced non-linear, non-periodic resonance oscillations using moderate amplitudes of forcing pressure. The key feature of this new method is a coordination of the forced liquid pressure change with the change of bubble volume. The corresponding regime of the bubble oscillation has been called {open_quotes}basketball dribbling (BD) regime{close_quotes}. The analytical solution describing this process for spherically symmetric bubble oscillations, neglecting dissipation and compressibility of the liquid, has been obtained. This solution shown no limitation on the supercompression of the bubble and the corresponding maximum temperature. The various dissipation mechanisms, including viscous, conductive and radiation heat losses have been considered. It is shown that in spite of these losses it is possible to achieve very high gas bubble temperatures. This because the time duration of the gas bubble supercompression becomes very short when increasing the intensity of compression, thus limiting the energy losses. Significantly, the calculated maximum gas temperatures have shown that nuclear fusion may be possible. First estimations of the affect of liquid compressibility have been made to determine possible limitations on gas bubble compression. The next step will be to investigate the role of interfacial instability and breaking down of the bubble, shock wave phenomena around and in the bubble and mutual diffusion of the gas and the liquid.

  18. Scaling and passively Q-switch operation of a Nd:YAG laser pumped laterally through a YAG prism

    Science.gov (United States)

    Dascalu, T.; Salamu, G.; Sandu, O.; Dinca, M.; Pavel, N.

    2015-04-01

    We report on scaling of a laser configuration in which a YAG prism is used to couple the pump beam from a fiber-coupled diode laser directly into a Nd:YAG medium. Several resonator geometries have been investigated. In free generation regime laser pulses at 1.06 μm with energy of 22.1 mJ for the pump energy of 44.6 mJ were obtained from a 10.0 mm long, 1.0-at% Nd:YAG single crystal that had the high-reflectivity mirror coated directly on one of the laser crystal surface. The slope efficiency was 0.51. A similar uncoated Nd:YAG crystal placed in a plane-plane resonator delivered laser pulses with 17.8 mJ energy under the pump with 45.4 mJ energy, at 0.40 slope efficiency. Further, a passively Q-switched Nd:YAG/Cr4+:YAG composite ceramic laser pumped through a YAG prism has been built. Using a Cr4+:YAG saturable absorber of 0.85 initial transmission the device delivered laser pulses with 0.29 mJ energy and 11 ns duration. The output performances are compared to those obtained in a classical end-pumping scheme.

  19. Orbital Liquid Oxygen Pump Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed work will develop a pump, which is based on two novel and unique design features. The first feature is a lobed pumping mechanism which operates with...

  20. Turbulence, bubbles and drops

    NARCIS (Netherlands)

    Veen, van der Roeland Cornelis Adriaan

    2016-01-01

    In this thesis, several questions related to drop impact and Taylor-Couette turbulence are answered. The deformation of a drop just before impact can cause a bubble to be entrapped. For many applications, such as inkjet printing, it is crucial to control the size of this entrapped bubble. To study t

  1. Bubbles in graphene

    DEFF Research Database (Denmark)

    Settnes, Mikkel; Power, Stephen; Lin, Jun

    2015-01-01

    Strain-induced deformations in graphene are predicted to give rise to large pseudomagnetic fields. We examine theoretically the case of gas-inflated bubbles to determine whether signatures of such fields are present in the local density of states. Sharp-edged bubbles are found to induce Friedel...

  2. Evaporation, Boiling and Bubbles

    Science.gov (United States)

    Goodwin, Alan

    2012-01-01

    Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

  3. Evaporation, Boiling and Bubbles

    Science.gov (United States)

    Goodwin, Alan

    2012-01-01

    Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

  4. Single bubble sonoluminescence

    NARCIS (Netherlands)

    Brenner, Michael P.; Hilgenfeldt, Sascha; Lohse, Detlef

    2002-01-01

    Single-bubble sonoluminescence occurs when an acoustically trapped and periodically driven gas bubble collapses so strongly that the energy focusing at collapse leads to light emission. Detailed experiments have demonstrated the unique properties of this system: the spectrum of the emitted light ten

  5. Single bubble sonoluminescence

    NARCIS (Netherlands)

    Brenner, Michael P.; Hilgenfeldt, Sascha; Lohse, Detlef

    2002-01-01

    Single-bubble sonoluminescence occurs when an acoustically trapped and periodically driven gas bubble collapses so strongly that the energy focusing at collapse leads to light emission. Detailed experiments have demonstrated the unique properties of this system: the spectrum of the emitted light

  6. Bubble collision with gravitation

    CERN Document Server

    Hwang, Dong-il; Lee, Wonwoo; Yeom, Dong-han

    2012-01-01

    In this paper, we study vacuum bubble collisions with various potentials including gravitation, assuming spherical, planar, and hyperbolic symmetry. We use numerical calculations from double-null formalism. Spherical symmetry can mimic the formation of a black hole via multiple bubble collisions. Planar and especially hyperbolic symmetry describes two bubble collisions. We study both cases, when two true vacuum regions have the same field value or different field values, by varying tensions. For the latter case, we also test symmetric and asymmetric bubble collisions, and see details of causal structures. If the colliding energy is sufficient, then the vacuum can be destabilized, and it is also demonstrated. This double-null formalism can be a complementary approach in the context of bubble collisions.

  7. Gas dispersion and bubble-to-emulsion phase mass exchange in a gas-solid bubbling fluidized bed: a computational and experimental study

    NARCIS (Netherlands)

    Patil, Dhaneshwar J.; Sint Annaland, van Martin; Kuipers, J.A.M.

    2003-01-01

    Knowledge of gas dispersion and mass exchange between the bubble and the emulsion phases is essential for a correct prediction of the performance of fluidized beds, particularly when catalytic reactions take place. Test cases of single rising bubble and a bubbling fluidized bed operated with a jet w

  8. Recent Operational Experience with the Internal Thermal Control System Dual-Membrane Gas Trap

    Science.gov (United States)

    Leimkuehler, Thomas O.; Lukens, Clark; Reeves, Daniel R.; Holt, James M.

    2004-01-01

    A dual-membrane gas trap is currently used to remove gas bubbles from the Internal Thermal Control System (ITCS) coolant on board the International Space Station. The gas trap consists of concentric tube membrane pairs, comprised of outer hydrophilic tubes and inner hydrophobic fibers. Liquid coolant passes through the outer hydrophilic membrane, which traps the gas bubbles. The inner hydrophobic fiber allows the trapped gas bubbles to pass through and vent to the ambient atmosphere in the cabin. The gas removal performance and operational lifetime of the gas trap have been affected by contamination in the ITCS coolant. However, the gas trap has performed flawlessly with regard to its purpose of preventing gas bubbles from causing depriming, overspeed, and shutdown of the ITCS pump. This paper discusses on-orbit events over the course of the last year related to the performance and functioning of the gas trap.

  9. Bubble Content in Air/Hydro System--Part 2:Factors Influencing Bubble Content

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new method for measuring bubble content of two-phase fluids in complex systems such as air/hydro systems has been designed and verified. Some new results of the study on the factors influencing bubble content using this new method are given in this paper, including the results of the experiments in the SKIP-valve system and long-tube system. Results indicate that the operating time, opening of the control-valve, air supply pressure, mass of the load, speed ratio, and the length of the tube all affect bubble content.

  10. Operation of an InAs quantum-dot embedded GaAs photonic crystal slab waveguide laser by using two-photon pumping for photonics integrated circuits

    Directory of Open Access Journals (Sweden)

    H. Oda

    2016-06-01

    Full Text Available The development of small sized laser operating above room temperature is important in the realization of optical integrated circuits. Recently, micro-lasers consisting of photonic crystals (PhCs and whispering gallery mode cavities have been demonstrated. Optically pumped laser devices could be easily designed using photonic crystal-slab waveguides (PhC-WGs with an air-bridge type structure. In this study, we observe lasing at 1.3μm from two-photon pumped InAs-quantum-dots embedded GaAs PhC-WGs above room temperature. This type of compact laser shows promise as a new light source in ultra-compact photonics integrated circuits.

  11. Initial operation of a new generation of highly efficient absorption heat pumps in Maastricht/Netherlands. Inbetriebnahme einer neuen Generation hocheffizienter Absorptionswaermepumpen in Maastricht/NL

    Energy Technology Data Exchange (ETDEWEB)

    Schneider-Weyergraf, R. (Ingenieurbuero Colibri (Netherlands)); Veelken, H. (Ingenieurbuero Colibri (Netherlands))

    1993-12-01

    No better place or time could have been chosen: In april '93, two weeks before the opening of the 4. Int. HEAT PUMP CONFERENCE in Maastricht/NL, the first type of a new generation of high efficient absorption heat pumps was installed in the government building in Maastricht. The ABRES 250 is a gas driven machine, which is operating with ammonia as the refrigerant. Her special merits are her high efficiency and her compactness. The high COP (coefficient of performance) is realised by a perfected process, by which the machine is driven continuously between a single- and two-stage process depending on the working conditions. Its low size results from the consequent use of compact heat exchangers of the plate-fin-heat-exchanger type. (orig.)

  12. Research and technological development on heat pumps in Mexico operating with geothermal energy; Investigacion y desarrollo tecnologico sobre bombas de calor en Mexico operando con energia geotermica

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Gutierrez, Alfonso; Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    The Instituto de Investigaciones Electricas (IIE) and the Comision Federal de Electricidad (CFE) carried out in the past an extensive work of research and development (R&D) on heat pumps (HP). The systems tried on include heat pumps by mechanical compression, thermal absorption and thermal transformers. This paper briefly describes the main aspects of R&D on heat pumps and presents a more detailed description of three of the main studies: a) a Heat Pump (HP) by mechanical compression water-water type, designed for brine purification, operating with low pressure geothermal steam at the geothermal field Los Azufres, Michoacan, Mexico; b) a HP by absorption for cooling and refrigeration, operating with ammoniac/water and low enthalpy geothermal energy, which was tested in the geothermal fields of Los Azufres, Michoacan and Cerro Prieto, Baja California, and c) a thermal transformer by absorption, named Heat Pump by Absorption Type 2, which was tested to evaluate the behavior of diverse ternary solutions as working fluids. To date, there are plans to install and test a geothermal heat pump (connected to the subsoil), in Cerro Prieto, Mexicali, Baja California, Mexico. [Spanish] El Instituto de Investigaciones Electricas (IIE) y la Comision Federal de Electricidad (CFE) realizaron un trabajo extenso de investigacion y desarrollo (I&D) sobre bombas de calor (BC) en el pasado. Los sistemas que se probaron incluyen bombas de calor por compresion mecanica, absorcion y transformadores termicos. Este trabajo describe brevemente los principales aspectos de I&D sobre bombas de calor y se da una descripcion mas detallada de tres de los principales estudios: a) una Bomba de Calor (BC) por compresion mecanica tipo agua-agua, disenada para purificacion de salmueras, operando con vapor geotermico de baja presion en el campo geotermico de Los Azufres, Michoacan; b) una BC por absorcion para enfriamiento y refrigeracion, operando con amoniaco/agua y energia geotermica de baja entalpia

  13. Simultaneous tri-wavelength laser operation at 916, 1086, and 1089 nm of diode-pumped Nd:LuVO4 crystal

    Science.gov (United States)

    Shen, Bingjun; Jin, Lihong; Zhang, Jiajia; Tian, Jian

    2016-09-01

    We report a diode-pumped continuous-wave tri-wavelength Nd:LuVO4 laser operating at 916, 1086, and 1089 nm. A theoretical analysis has been introduced to determine the threshold conditions for simultaneous tri-wavelength laser operation. Using a T-shaped cavity, we realized efficient tri-wavelength operation at 4F3/2  →  4I9/2 and 4F3/2  →  4I11/2 transitions for Nd:LuVO4 crystal, simultaneously. The maximum output power was 2.8 W, which included 916, 1086, and 1089 nm, and the optical conversion efficiency was 15.1%. To our knowledge, this is the first work that realizes simultaneous tri-wavelength Nd:LuVO4 laser operation.

  14. Effect of bubble size on nanofiber diameter in bubble electrospinning

    Directory of Open Access Journals (Sweden)

    Ren Zhong-Fu

    2016-01-01

    Full Text Available Polymer bubbles are widely used for fabrication of nanofibers. Bubble size affects not only bubble's surface tension, but also fiber's morphology. A mathematical model is established to reveal the effect of bubble size on the spinning process, and the experiment verification shows the theoretical analysis is reliable.

  15. Water Treatment Technology - Pumps.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on pumps provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pumps in plant and distribution systems, pump…

  16. Refrigerating systems for the big CERN bubble chamber

    CERN Document Server

    Giger, U; Trepp, C

    1974-01-01

    A combined helium-hydrogen refrigerator has been installed for cooling the new CERN bubble chamber at Geneva. This article describes the cool-down of the bubble chamber and magnet, as well as emergency operation and control of the refrigerator. Besides the choice of basic conception and circuit, the plant components are dealt with too. The function of the bubble chamber and the development of the CERN proton synchrotron are described in order to facilitate understanding of the relationship between the Sulzer cryogenic plant and the CERN bubble chamber. Installations and equipment not manufactured by Sulzer are also mentioned. (1 refs).

  17. Thermo-pumps: their operating principles, the Vivrelec program; Les thermopompes: principes de fonctionnement, le programme Vivrelec

    Energy Technology Data Exchange (ETDEWEB)

    Horber, B. [Electricite de France (EDF), 75 - Paris (France)

    1997-12-31

    The Vivrelec EDF (Electricite de France) program is aimed at ensuring thermal comfort for residential homes, based on thermal performance (building insulation, ventilation), a range of electric heating equipment, programming and energy management systems, and services. In the framework of Vivrelec, reverse cycle refrigerating circuits are also proposed; its main principles are reviewed, based on two refrigerant/air heat exchangers, a compressor, a pressure reducing valve and a four-way valve. Energy and acoustic performances have been notably enhanced through the use of rotary compressors, brazed plate exchangers and advanced tubular exchangers, electronic regulation, etc. Three types of equipment are available: air conditioners, reverse air/water heat pumps (low or medium temperature) and ground-glycol water/water heat pumps (low and medium temperature)

  18. Detection of pump degradation

    Energy Technology Data Exchange (ETDEWEB)

    Casada, D. [Oak Ridge National Lab., TN (United States)

    1995-04-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous special vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Pump head and flow rate are also monitored, per code requirements. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition; advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  19. Effects of Swirl Bubble Injection on Mass Transfer and Hydrodynamics for Bubbly Flow Reactors: A Concept Paper

    Directory of Open Access Journals (Sweden)

    Farooqi Ahmad Salam

    2017-01-01

    Full Text Available Bubble flow reactors (BFR are commonly used for various industrial processes in the field of oil and gas production, pharmaceutical industries, biochemical and environmental engineering etc. The operation and performance of these reactors rely heavily on a range of hydrodynamic parameters; prominent among them are geometric configurations including gas injection geometry, operating conditions, mass transfer etc. A huge body of literature is available to describe the optimum design and performance of bubbly flow reactors with conventional bubble injection. Attempts were made to modify gas injection for improved efficiency of BFR’s. However, here instead of modifying the geometry of the gas injection, an attempt has been made to generate swirl bubbles for gaining larger mass transfer between gas and liquid. Here an exceptionally well thought strategies have been used in our numerical simulations towards the design of swirl injection mechanism, whose paramount aspect is to inhibit the rotary liquid motion but facilitates the swirl movement for bubbles in nearly stationary liquid. Our comprehension here is that the swirl motion can strongly affect the performance of bubbly reactor by identifying the changes in hydrodynamic parameters as compared to the conventional bubbly flows. In order to achieve this bubbly flow, an experimental setup has been designed as well as computational fluid dynamic (CFD code was used with to highlight a provision of swirl bubble injection by rotating the sparger plate.

  20. New Pump and Treat Facility Remedial Action Work Plan for Test Area North (TAN) Final Groundwater Remediation, Operable Unit 1-07B

    Energy Technology Data Exchange (ETDEWEB)

    D. Vandel

    2003-09-01

    This remedial action work plan identifies the approach and requirements for implementing the medical zone remedial action for Test Area North, Operable Unit 1-07B, at the Idaho National Engineering and Environmental Laboratory (INEEL). This plan details management approach for the construction and operation of the New Pump and Treat Facility. As identified in the remedial design/remedial action scope of work, a separate remedial design/remedial action work plan will be prepared for each remedial component of the Operable Unit 1-07B remedial action. This work plan was originally prepared as an early implementation of the final Phase C remediation. At that time, The Phase C implementation strategy was to use this document as the overall Phase C Work Plan and was to be revised to include the remedial actions for the other remedial zones (hotspot and distal zones). After the completion of Record of Decision Amendment: Technical Support Facility Injection Well (TSF-05) and Surrounding Groundwater Contamination (TSF-23) and Miscellaneous No Action Sites, Final Remedial Action, it was determined that each remedial zone would have it own stand-alone remedial action work plan. Revision 1 of this document converts this document to a stand-alone remedial action plan specific to the implementation of the New Pump and Treat Facility used for plume remediation within the medical zone of the OU 1-07B contaminated plume.

  1. Chemistry in Soap Bubbles.

    Science.gov (United States)

    Lee, Albert W. M.; Wong, A.; Lee, H. W.; Lee, H. Y.; Zhou, Ning-Huai

    2002-01-01

    Describes a laboratory experiment in which common chemical gases are trapped inside soap bubbles. Examines the physical and chemical properties of the gases such as relative density and combustion. (Author/MM)

  2. Chemistry in Soap Bubbles.

    Science.gov (United States)

    Lee, Albert W. M.; Wong, A.; Lee, H. W.; Lee, H. Y.; Zhou, Ning-Huai

    2002-01-01

    Describes a laboratory experiment in which common chemical gases are trapped inside soap bubbles. Examines the physical and chemical properties of the gases such as relative density and combustion. (Author/MM)

  3. Popping the Bubble

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Government adopts regulations to control real estate prices A mid concerns surrounding the presence of housing bubbles across China,the Chinese Government is taking action to secure and stabilize the real

  4. Centrifugal pumps

    CERN Document Server

    Anderson, HH

    1981-01-01

    Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

  5. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  6. Bubbling Out of Control

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Jim Chanos,founder of the U.S. hedge fund Kynikos Associates,characterized the prop-erty bubble in China as "Dubai times 1,000-or worse." Many Chinese economists agree. Yi Xianrong,a senior researcher at the Institute of Finance and Banking under the Chinese Academy of Social Sciences,said the property bubble in China was far worse than the Dubai crisis in an interview with the Beijing-based International Herald Leader. Edited excerpts follow:

  7. Pumping life

    DEFF Research Database (Denmark)

    Sitsel, Oleg; Dach, Ingrid; Hoffmann, Robert Daniel

    2012-01-01

    of membrane proteins: P-type ATPase pumps. This article takes the reader on a tour from Aarhus to Copenhagen, from bacteria to plants and humans, and from ions over protein structures to diseases caused by malfunctioning pump proteins. The magazine Nature once titled work published from PUMPKIN ‘Pumping ions......’. Here we illustrate that the pumping of ions means nothing less than the pumping of life....

  8. Accuracy of bubble velocity measurement with a four-point optical fibre probe

    NARCIS (Netherlands)

    Bai, Wei; Deen, Niels G.; Mudde, Robert F.; Kuipers, J.A.M.

    2008-01-01

    For the operation of high void fraction bubbly flows in bubble columns, insight in primary parameters such as bubble size, shape and velocity as well as gas volume fraction is essential. At high gas volume fractions the flow system becomes opaque, ruling out non-intrusive optical techniques. As an a

  9. First Demonstration of a Scintillating Xenon Bubble Chamber for Dark Matter and CE$\

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, D. [Fermilab; Chen, C. J. [Northwestern U.; Crisler, M. [PNL, Richland; Cwiok, T. [Northwestern U.; Dahl, C. E. [Fermilab; Grimsted, A. [Evanston Township High School; Gupta, J. [Northwestern U.; Jin, M. [Northwestern U.; Puig, R. [Northwestern U.; Temples, D. [Northwestern U; Zhang, J. [Northwestern U.

    2017-02-28

    A 30-gram xenon bubble chamber, operated at Northwestern University in June and November 2016, has for the first time observed simultaneous bubble nucleation and scintillation by nuclear recoils in liquid xenon. This chamber is instrumented with a CCD camera for near-IR bubble imaging, a solar-blind PMT to detect 175-nm xenon scintillation light, and a piezoelectric acoustic transducer to detect the ultrasonic emission from a growing bubble. The time-of-nucleation determined from the acoustic signal is used to correlate specific scintillation pulses with bubble-nucleating events. The observed single- and multiple-bubble rates when exposed to a $^{252}$Cf neutron source indicate that, for a thermodynamic "Seitz" threshold of 8.3 keV, the minimum nuclear recoil energy required to nucleate a bubble is between 11 and 25 keV. This is consistent with the observed scintillation spectrum for bubble-nucleating events. We see no evidence for bubble nucleation by gamma rays at the thresholds studied, setting a 90% CL upper limit of $6.3\\times10^{-7}$ bubbles per gamma interaction at a 4.2-keV thermodynamic threshold. This indicates stronger gamma discrimination than in CF$_3$I bubble chambers, supporting the hypothesis that scintillation production suppresses bubble nucleation by electron recoils, while nuclear recoils nucleate bubbles as usual. These measurements establish the noble-liquid bubble chamber as a promising new technology for WIMP and CE$\

  10. Direct Measurement of the Bubble Nucleation Energy Threshold in a CF3I Bubble Chamber

    CERN Document Server

    Behnke, E; Brice, S J; Broemmelsiek, D; Collar, J I; Cooper, P S; Crisler, M; Dahl, C E; Fustin, D; Hall, J; Harnish, C; Levine, I; Lippincott, W H; Moan, T; Nania, T; Neilson, R; Ramberg, E; Robinson, A E; Sonnenschein, A; Vázquez-Jáuregui, E; Rivera, R A; Uplegger, L

    2013-01-01

    We have directly measured the energy threshold and efficiency for bubble nucleation from iodine recoils in a CF3I bubble chamber in the energy range of interest for a dark matter search. These interactions cannot be probed by standard neutron calibration methods, so we develop a new technique by observing the elastic scattering of 12 GeV/c negative pions. The pions are tracked with a silicon pixel telescope and the reconstructed scattering angle provides a measure of the nuclear recoil kinetic energy. The bubble chamber was operated with a nominal threshold of (13.6+-0.6) keV. Interpretation of the results depends on the response to fluorine and carbon recoils, but in general we find agreement with the predictions of the classical bubble nucleation theory. This measurement confirms the applicability of CF3I as a target for spin-independent dark matter interactions and represents a novel technique for calibration of superheated fluid detectors.

  11. Solids mixing in bubbling fluidized beds: CFD-based analysis of Bubble Dynamics and Time Scales

    Science.gov (United States)

    Bakshi, Akhilesh; Altantzis, Christos; Ghoniem, Ahmed

    2016-11-01

    In bubbling fluidized bed reactors, solids mixing is critical because it directly affects fuel segregation and residence time. However, there continues to be a lack of understanding because (a) most diagnostic techniques are only feasible in lab-scale setups and (b) the dynamics are sensitive to the operating conditions. Thus, quantitative estimates of mixing (e.g., dispersion coefficient, mixing indices) often span orders of magnitude although it is well accepted that the micro-mixing and gross circulation of solid particles is driven by bubble motion. To quantify this dependence, solids mixing is investigated using fine-grid 3D CFD simulations of a large 50 cm diameter fluidized bed. Detailed diagnostics of the computed flow-field data are performed using MS3DATA, a tool that we developed to detect and track bubbles, and the solids motion is correlated with the spatial and size distribution of bubbles. This study will be useful for quantifying mixing at commercial scales.

  12. Model and operation strategy of pumped-storage in hybrid power system%多能互补发电系统抽水蓄能模型及运行策略

    Institute of Scientific and Technical Information of China (English)

    任岩; 郑源; 周兵; 郭齐珂

    2013-01-01

    Based on the characteristics of hybrid power system, a mathematical model of pumped-storage was established. According to its function, the pumped-storage operation strategy was put forward, that is, to operate as per given load and specifically in the hybrid wind-PV-pumped-storage system, to operate as per net load. A control model of pumped-storage was accordingly proposed; as the net load was greater than zero, the pumped-storage unit operated under the turbine operating conditions could be classified into three situations. Firstly, as net load was less than the starting power of turbine, pumped-storage units were not operating. Secondly, as net load was greater than the starting power and less than the rated power of turbine, pumped-storage units were operating at the turbine condition as net load power. Thirdly, as net load was less than the rated power of turbine, pumped-storage units were operating as the rated power of turbine. When net load was less than zero, pumped-storage units operated under the pump operating conditions could be classified into two situations. Firstly, as net load was less than the rated power of pump, pumped-storage units were not operating. Secondly, as net load was greater than the rated power of pump, pumped-storage units were operating as the rated power of pump.%根据多能互补发电系统的特点和作用,建立了系统中抽水蓄能的数学模型,提出了系统中抽水蓄能的运行策略,即按给定负荷运行,具体在本系统中即为按系统净负荷运行.由此提出系统中抽水蓄能的控制方式.当系统净负荷大于0时,抽水蓄能机组运行在水轮机工况,分3种情况:当系统净负荷小于水轮机工况的启动功率时,抽水蓄能机组不运行;当系统净负荷大于水轮机工况的启动功率而小于水轮机工况的额定功率时,抽水蓄能机组按净负荷功率运行在水轮机工况;当系统净负荷小于水轮机的额定功率时,抽水蓄能机组按水

  13. Automatic Control of Water Pumping Stations

    Institute of Scientific and Technical Information of China (English)

    Muhannad Alrheeh; JIANG Zhengfeng

    2006-01-01

    Automatic Control of pumps is an interesting proposal to operate water pumping stations among many kinds of water pumping stations according to their functions.In this paper, our pumping station is being used for water supply system. This paper is to introduce the idea of pump controller and the important factors that must be considering when we want to design automatic control system of water pumping stations. Then the automatic control circuit with the function of all components will be introduced.

  14. Pompe de chaleur fonctionnant avec un mélange de fluides Heat Pump Operating with a Fluid Mixture

    Directory of Open Access Journals (Sweden)

    Vidal J.

    2006-11-01

    Full Text Available Lorsqu'une pompe de chaleur échange de la chaleur avec des fluides extérieurs, dont la température évolue au cours de l'échange, il est possible d'augmenter le coefficient de performance en utilisant comme fluide de travail un mélange non-azéotropique qui se vaporise et se condense suivant une évolution de température parallèle à celle du fluide extérieur avec lequel s'effectue cet échange. L'utilisation de mélanges dans les pompes de chaleur a été étudiée, d'une part, au moyen de modèles de simulation sur ordinateur et, d'autre part, au moyen d'essais expérimentaux. Différentes applications ont été examinées à la fois dans le domaine du chauffage résidentiel et dans le domaine industriel. Whenever heat is recovered and delivered, the coefficient of performance of a heat pump can be increased by using a fluid mixture selected to have a temperature variation, during the vaporization and condensation stages, parallel to that of the outside fluid with which the heat exchange takes place. Such a solution was investigated both theoretically and experimentally. It has been shown that significant savings can be expected, ranging up to 50% of the energy consumption of conventional heat pumps in some cases. Various applications for home and industrial heating have been examined, and the economic prospects have been found to be satisfactory. Further work is needed to develop such heat pumps on a commercial basis.

  15. Golden Jubilee photos: The first CERN bubble chamber

    CERN Multimedia

    2004-01-01

    In the 1950s and 1960s, bubble and spark chambers were the dominant experimental tools in high-energy physics. While spark chambers were usually built and fitted to specific experiments, bubble chambers were constructed as general purpose devices that could be used for a variety of experiments. At CERN, the bubble chamber programme started under Charles Peyrou in the late 1950s. The first of CERN's bubble chambers, a 30 cm hydrogen chamber, is seen here being inserted into its vacuum tank. The HBC30, as it was called, took its first beam from the SC in 1959. One of the first pictures taken, of a positive pion-proton interaction, began a long series of pretty images for which bubble chambers would become famous. When it stopped operating in spring 1962, the HBC30 had consumed 150 km of film in its 3 years of operation.

  16. Optimization of bubble column performance for nanoparticle collection.

    Science.gov (United States)

    Cadavid-Rodriguez, M C; Charvet, A; Bemer, D; Thomas, D

    2014-04-30

    Fibrous media embody the most effective and widely used method of separating ultrafine particles from a carrier fluid. The main problem associated with them is filter clogging, which induces an increasingly marked pressure drop with time and thus imposes regular media cleaning or replacement. This context has prompted the idea of investigating bubble columns, which operate at constant pressure drop, as alternatives to fibrous filters. This study examines the influence of different operating conditions, such as liquid height, air flow rate, bubble size and presence of granular beds on ultrafine particle collection. Experimental results show that bubble columns are characterised by high collection efficiency, when they feature a large liquid height and small diameter bubbling orifices, while their efficiencies remain lower than those of fibrous filters. Gas velocity does not greatly influence collection efficiency, but the inclusion of a granular bed, composed of beads, increases the bubble residence time in the column, thereby increasing the column collection efficiency.

  17. Análise operacional de um sistema fotovoltaico de bombeamento de água Operational analysis of a photovoltaic water pumping (PV system

    Directory of Open Access Journals (Sweden)

    Evandro M. Kolling

    2004-12-01

    Full Text Available O bombeamento de água é uma das atividades mais difundidas quanto ao emprego da energia solar fotovoltaica. Porém, apesar de se apresentar como alternativa interessante, o alto custo, a baixa eficiência dos sistemas e os projetos inadequados restringem sua aplicação. O uso racional, baseado na utilização mais eficiente de seus equipamentos, está vinculado ao conhecimento do comportamento operacional desses sistemas. No presente trabalho, teve-se o objetivo de avaliar o comportamento de um sistema fotovoltaico de bombeamento de água diretamente acoplado, sob diferentes condições de irradiância solar, por meio da montagem de uma bancada de testes, submetendo-o a diferentes alturas manométricas e determinando-se a vazão fornecida. A análise dos resultados permitiu estabelecer um modelo de regressão para estimativa de vazão do sistema em função da irradiância e altura manométrica. Concluiu-se que a potência gerada pelo painel e a vazão fornecida pela motobomba estão diretamente relacionadas à irradiância solar e à altura manométrica e influenciam na eficiência do sistema. A máxima eficiência do painel foi de 8%, 39% para a motobomba e 2,3% na interação dos componentes.The pumping of water is one of the activities most diffused to the employment of the photovoltaic solar energy, in spite of coming as an interesting alternative, the high cost and it lowers efficiency of the systems with the inadequate projects, still restricts its application. The rational use, based on the most efficient use of its equipments is linked to the knowledge of the operational behavior of these systems. The present work objectified to evaluate the operational behavior of a photovoltaic water pumping directly coupled operating in different conditions of solar irradiance, by means of the assembly of supported tests, submitting to different manometer elevation and determining the supplied rate flux of water. The analysis of the results

  18. Study of air-liquid flow patterns in hydrocyclone enhanced by air bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Z.; Wang, H.; Tu, S.T. [School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai (China)

    2009-01-15

    In order to improve the oil-water separation efficiency of a hydrocyclone, a new process utilizing air bubbles has been developed to enhance separation performance. Using the two-component phase Doppler particle analyzer (PDPA) technique, the velocities of two phases, air and liquid, and air bubble diameter were measured in a hydrocyclone. The air-liquid mixing pump can produce 15 to 60 {mu}m-diameter air bubbles in water. There is an optimum air-liquid ratio for oil-water separation of a hydrocyclone enhanced by air bubbles. An air core occurs in the hydrocyclone when the air-liquid ratio is more than 1 %. The velocities of air bubbles have a similar flow pattern to the water phase. The axial and tangential velocity differences of the air bubbles at different air-liquid ratio are greater near the wall and near the core of the hydrocyclone. The measured results show that the size distribution of the air bubbles produced by the air-liquid mixing pump is beneficial to the process where air bubbles capture oil droplets in the hydrocyclone. These studies are helpful to understand the separation mechanism of a hydrocyclone enhanced by air bubbles. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  19. He-Cd lasers operating at wavelengths of 442, 534, and 538 nm and pumped by a nanosecond electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Derzhiev, V.I.; Zhidkov, A.G.; Karelin, A.V.; Nagornyi, D.IU.; Skakun, V.S.

    1988-01-01

    Effective lasing was obtained with an He-Cd laser in blue (442 nm) and green (534 and 538 nm) under nanosecond-electron-beam pumping. The dependence of the lasing characteristics on gas temperature and cold-helium pressure is examined along with the time characteristics of lasing. The maximum power was 200 W for the blue line and 400 W for the green lines; the efficiency with respect to energy injected into the active region was 0.1 percent. 6 references.

  20. Thermodynamic analysis of a novel compact power generation and waste heat operated absorption, ejector-jet pump refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Anil; Kumar, Raj [YMCA University of Science and Technology, Faridabad (India)

    2014-09-15

    An R-152a ejector-jet pump refrigeration cycle and a LiBr-H{sub 2}O absorption refrigeration cycle have been integrated with a renewable energy power generator for making a proposed 'novel compact cogeneration cycle'. The exergy analysis of this proposed cycle leads to a possible performance improvement. Nearly 71.12% of the input exergy is destructed due to irreversibilities in the different components. The useful exergy output is around 7.12%. The exhaust exergy lost to the environment is 21.76%, which is lower than the exhaust energy lost 37.6% of the input energy, while the useful energy output is approximately 19.3%. The refrigerants used and the exhaust gas emissions samples are found to be favourable for reducing the global environmental related problems. The results also show that the coupling of the entrainment ratios of the ejector and jet pump has great effect on the exergy and energy efficiency.

  1. Bubble Formation Characteristics from a Sieve Tray with Liquid Cross—flow

    Institute of Scientific and Technical Information of China (English)

    XUSonglin; XUShimin

    2002-01-01

    An apparatus,desinged to simulate bubbling of a sieve tray operated in froth regime,was employed. Bubble contact angles in and above the incipient weeping regimer for an air-water-plexiglas system were investigated. The influence of both liquid cross-flow and gas up-flow upon bubble contact angles was examined. A model considering the influence of liquid cross-flow was developed to predict bubble size from a sieve hole in froth operation regime.The comparison shows that the bubble sizes predicted by the present model are consistent with our experimental values and the available published experimental data.

  2. Retrofitting the Operation Condition Around Air Cooled Heat Pump at Kirin Plaza%嘉麒大厦风冷热泵工作环境节能改造实例

    Institute of Scientific and Technical Information of China (English)

    郏京武

    2014-01-01

    风冷热泵的布置位置、周围空气通风情况、是否受太阳光直射等因素影响着风冷热泵的运行效果。通过将风冷热泵附近固定窗改为百叶,在风冷热泵出风口增加钢质拔风罩,以及夏季对风冷热泵冷凝器翅片进行喷雾等措施,改善了风冷热泵的运行环境。%Some factors influence the operation of air cooled heat pump. The location of the heat pump, the ventilation around heat pump and the sunshine can directly act on heat pump. Improving method for the operation condition around the heat pumps on site are expounded, including changing fixed window glasses to louvers, installing steel downstream at the air outlets of heat pump and installing water spray sys-tem for condenser fins of heat pumps.

  3. Colliding with a crunching bubble

    Energy Technology Data Exchange (ETDEWEB)

    Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T.; Shenker, Stephen

    2007-03-26

    In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.

  4. Determination of the best operation point of a solar pumping systems user to water a crop; Determinacion del punto optimo de funcionamiento dinamico en equipos de bombeo solar utilizados para riegos

    Energy Technology Data Exchange (ETDEWEB)

    Cuadros, E.; Silos, I.; Marcos, A.; Lopez-Rodriguez, F.

    2004-07-01

    In this article it is estimated the best operation point of a solar pumping system used to water a crop. This point depends on 1) the climate characteristic of the zone, 2) the watering demands of the crop and, 3) the characteristic of the solar pumping system, like flow-area-height-frequency of the inversor-variator. In this work are analyzed and commented the results obtained from the group of pressure/height curves of a 1 HP pump powered by a 1.100 W photovoltaic system according to the frequency of the inversor /variator, during the summer time. (Author)

  5. Investigation of bubble-bubble interaction effect during the collapse of multi-bubble system

    Science.gov (United States)

    Shao, Xueming; Zhang, Lingxin; Wang, Wenfeng

    2014-11-01

    Bubble collapse is not only an important subject among bubble dynamics, but also a key consequence of cavitation. It has been demonstrated that the structural damage is associated with the rapid change in flow fields during bubble collapse. How to model and simulate the behavior of the bubble collapse is now of great interest. In the present study, both theoretical analysis and a direct numerical simulation on the basis of VOF are performed to investigate the collapses of single bubble and bubble cluster. The effect of bubble-bubble interaction on the collapse of multi-bubble system is presented. The work was supported by the National Natural Science Foundation of China (11272284, 11332009).

  6. MEASUREMENT OF BUBBLE-BUBBLE INTERACTION DEPENDED ON REYNOLDS NUMBER USING STEREOSCOPIC BUBBLE-TRACKING TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    QU Jian-wu; MURAI Yuichi; YAMAMOTO Fujio

    2005-01-01

    Bubble-bubble interaction in free rising bubbly flows is experimentally investigated in the present study.The velocity vectors of the bubbles are measured by a stereoscopic bubble-tracking technique and then the relative velocity vectors of two nearest-neighbor bubbles are calculated with high statistical reliability.With the measurement data at Reynolds number ranging from 5 to 75, the vertical attraction and the horizontal repulsion are confirmed for Re<10 as known by the past study based on Navier-Stokes simulation.The new finding of the present measurement is that the bubbles of Re>30 have repulsive velocity bothin the horizontal and the vertical directions as those rise closely.Moreover, the three-dimensional structure of the bubble-bubble interaction is discussed with the data analysis of the interaction vector fields.

  7. Fermi Bubbles with HAWC

    CERN Document Server

    Solares, H A Ayala; Hüntemeyer, P

    2015-01-01

    The Fermi Bubbles, which comprise two large and homogeneous regions of spectrally hard gamma-ray emission extending up to $55^{o}$ above and below the Galactic Center, were first noticed in GeV gamma-ray data from the Fermi Telescope in 2010. The mechanism or mechanisms which produce the observed hard spectrum are not understood. Although both hadronic and lep- tonic models can describe the spectrum of the bubbles, the leptonic model can also explain similar structures observed in microwave data from the WMAP and Planck satellites. Recent publications show that the spectrum of the Fermi Bubbles is well described by a power law with an exponential cutoff in the energy range of 100MeV to 500GeV. Observing the Fermi Bubbles at higher gamma-ray energies will help constrain the origin of the bubbles. A steeper cutoff will favor a leptonic model. The High Altitude Water Cherenkov (HAWC) Observatory, located 4100m above sea level in Mexico, is designed to measure high-energy gamma rays between 100GeV to 100TeV. With...

  8. Bubbles, shocks and elementary technical trading strategies

    Science.gov (United States)

    Fry, John

    2014-01-01

    In this paper we provide a unifying framework for a set of seemingly disparate models for bubbles, shocks and elementary technical trading strategies in financial markets. Markets operate by balancing intrinsic levels of risk and return. This seemingly simple observation is commonly over-looked by academics and practitioners alike. Our model shares its origins in statistical physics with others. However, under our approach, changes in market regime can be explicitly shown to represent a phase transition from random to deterministic behaviour in prices. This structure leads to an improved physical and econometric model. We develop models for bubbles, shocks and elementary technical trading strategies. The list of empirical applications is both interesting and topical and includes real-estate bubbles and the on-going Eurozone crisis. We close by comparing the results of our model with purely qualitative findings from the finance literature.

  9. Magnetocaloric pump

    Science.gov (United States)

    Brown, G. V.

    1973-01-01

    Very cold liquids and gases such as helium, neon, and nitrogen can be pumped by using magnetocaloric effect. Adiabatic magnetization and demagnetization are used to alternately heat and cool slug of pumped fluid contained in closed chamber.

  10. Red and orange laser operation of Pr:KYF4 pumped by a Nd:YAG/LBO laser at 469.1 nm and a InGaN laser diode at 444 nm.

    Science.gov (United States)

    Xu, B; Starecki, F; Pabœuf, D; Camy, P; Doualan, J L; Cai, Z P; Braud, A; Moncorgé, R; Goldner, Ph; Bretenaker, F

    2013-03-11

    We report the basic luminescence properties and the continuous-wave (CW) laser operation of a Pr(3+)-doped KYF(4) single crystal in the Red and Orange spectral regions by using a new pumping scheme. The pump source is an especially developed, compact, slightly tunable and intra-cavity frequency-doubled diode-pumped Nd:YAG laser delivering a CW output power up to about 1.4 W around 469.1 nm. At this pump wavelength, red and orange laser emissions are obtained at about 642.3 and 605.5 nm, with maximum output powers of 11.3 and 1 mW and associated slope efficiencies of 9.3% and 3.4%, with respect to absorbed pump powers, respectively. For comparison, the Pr:KYF(4) crystal is also pumped by a InGaN blue laser diode operating around 444 nm. In this case, the same red and orange lasers are obtained, but with maximum output powers of 7.8 and 2 mW and the associated slope efficiencies of 7 and 5.8%, respectively. Wavelength tuning for the two lasers is demonstrated by slightly tilting the crystal. Orange laser operation and laser wavelength tuning are reported for the first time.

  11. Bubble nuclei; Noyaux Bulles

    Energy Technology Data Exchange (ETDEWEB)

    Legoll, F. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-07-22

    For nuclei with very high electrical charge, the Coulomb field is expected to drive the protons away from the centre to the surface of the nucleus. Such a nucleus would be no more compact but look like a bubble. The goal of this work is to confirm this idea. We are interested in only the ground state of spherical nuclei. We use the Skyrme potential with the Sly4 parametrization to calculate the mean-field Hamiltonian. Paring correlations are described by a surface-active delta paring interaction. In its ground state the nucleus {sup A=900} X{sub Z=274} is shown to be a bubble. Another stable state is found with a little higher energy: it is also a bubble. (author) 11 refs., 18 figs., 33 tabs.

  12. Bubble nuclei; Noyaux Bulles

    Energy Technology Data Exchange (ETDEWEB)

    Legoll, F. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-07-22

    For nuclei with very high electrical charge, the Coulomb field is expected to drive the protons away from the centre to the surface of the nucleus. Such a nucleus would be no more compact but look like a bubble. The goal of this work is to confirm this idea. We are interested in only the ground state of spherical nuclei. We use the Skyrme potential with the Sly4 parametrization to calculate the mean-field Hamiltonian. Paring correlations are described by a surface-active delta paring interaction. In its ground state the nucleus {sup A=900} X{sub Z=274} is shown to be a bubble. Another stable state is found with a little higher energy: it is also a bubble. (author) 11 refs., 18 figs., 33 tabs.

  13. Effects of surfactant on bubble hydrodynamic behavior under flotation-related conditions in wastewater.

    Science.gov (United States)

    Li, Yanpeng; Zhu, Tingting; Liu, Yanyan; Tian, Ye; Wang, Huanran

    2012-01-01

    Bubble behavior is fundamental to the performance of froth flotation operations used in wastewater treatment processes. To fully understand and characterize bubble behavior under flotation-related conditions in wastewater, the high-speed photographic method has been employed to examine the motion of single bubbles and size distribution of bubble swarms with intermediate sizes ranging from 1 to 4 mm in the presence of surfactants in a laboratory scale flotation column. Both distilled water and synthetic municipal wastewater have been used to make solutions as well as two types of common surfactants. The instantaneous bubble motion has been recorded by a high speed camera. Subsequently, bubble trajectory, dimensions, velocity and distribution have been determined from the recorded frames using the image analysis software. The experimental results show that the addition of surfactant into wastewater has similar effects on bubble hydrodynamic behavior as in pure water (e.g., improving trajectory stabilization, dampening bubble deformation, slowing down terminal velocity, reducing bubble size and increasing the specific surface area of bubble swarm) due to the Marangoni effect. However, it is interesting to note that surfactant effects on single bubble hydrodynamics in wastewater are slightly stronger than those in pure water while surfactant effects on size parameters of bubble swarms in wastewater are significantly stronger than those in pure water. This finding suggests that besides surfactant, inorganic salts present in synthetic wastewater have an important influence on bubble dispersion.

  14. Numerical simulation of bubble behavior in subcooled flow boiling under velocity and temperature gradient

    Energy Technology Data Exchange (ETDEWEB)

    Bahreini, Mohammad, E-mail: m.bahreini1990@gmail.com; Ramiar, Abas, E-mail: aramiar@nit.ac.ir; Ranjbar, Ali Akbar, E-mail: ranjbar@nit.ac.ir

    2015-11-15

    Highlights: • Condensing bubble is numerically investigated using VOF model in OpenFOAM package. • Bubble mass reduces as it goes through condensation and achieves higher velocities. • At a certain time the slope of changing bubble diameter with time, varies suddenly. • Larger bubbles experience more lateral migration to higher velocity regions. • Bubbles migrate back to a lower velocity region for higher liquid subcooling rates. - Abstract: In this paper, numerical simulation of the bubble condensation in the subcooled boiling flow is performed. The interface between two-phase is tracked via the volume of fluid (VOF) method with continuous surface force (CSF) model, implemented in the open source OpenFOAM CFD package. In order to simulate the condensing bubble with the OpenFOAM code, the original energy equation and mass transfer model for phase change have been modified and a new solver is developed. The Newtonian flow is solved using the finite volume scheme based on the pressure implicit with splitting of operators (PISO) algorithm. Comparison of the simulation results with previous experimental data revealed that the model predicted well the behavior of the actual condensing bubble. The bubble lifetime is almost proportional to bubble initial size and is prolonged by increasing the system pressure. In addition, the initial bubble size, subcooling of liquid and velocity gradient play an important role in the bubble deformation behavior. Velocity gradient makes the bubble move to the higher velocity region and the subcooling rate makes it to move back to the lower velocity region.

  15. Experimantal Study on the Bubble Clustering in Bubbly Flows

    Science.gov (United States)

    Takagi, Shu; Fujiwara, Akiko; Ogasawara, Toshiyuki; Matsumoto, Yoichiro

    2003-11-01

    The statistical properties of bubbly flows and the near-wall bubble-clustering behaviors are investigated for upward flow in a rectangular channel. Bubble size, turbulent properties of liquid phase and the bubble clustering motion were measured using image-processing technique, Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV), respectively. Using 3-pentanol as a surfactant, the mono-dispersed 1mm-bubbles are generated. The mono-dispersed bubbles in upward flows accumulate near the wall and construct bubble clusters. These bubble clusters were investigated. Experimental observation showed that the size of bubble cluster can be much larger than that of the coherent structure in single phase turbulence. The clusters change their shape in time and space and these bubble motions accelerate the mean streamwise velocity near the wall due to the buoyancy effect. Thus the mean velocity profile of the liquid phase becomes flattened. It is suggested that the highly accumulated bubbles in the vicinity of the wall disturb the transport of turbulence energy produced in the wall shear layer from the central region of the channel flow. Furthermore, in the middle of channel, the fluctuations of the liquid phase are mainly generated by the bubble motions.

  16. Pulmonary embolism caused by a carbon dioxide blower during off-pump coronary artery bypass grafting.

    Science.gov (United States)

    Hirata, Naoyuki; Kanaya, Noriaki; Yamazaki, Yutaka; Sonoda, Hajime; Namiki, Akiyoshi

    2010-02-01

    We report a rare case of pulmonary embolism (PE) caused by a carbon dioxide (CO2) blower during off-pump coronary artery bypass grafting (OPCAB). When the anastomosis of the right internal thoracic artery to left anterior descending artery was performed, the operator tore the right ventricle outflow track (RVOT) that was adjacent to the left anterior descending artery. Immediately after the anastomosis and repair of the torn RVOT with CO2 blower, the systolic pulmonary artery pressure (PAP) increased from 28 to 64 mmHg, and end-tidal CO2 decreased from 32 to 12 mmHg. Because transesophageal echocardiograph (TEE) showed numerous gas bubbles in the main pulmonary artery, we diagnosed PE caused by invasion of CO2 gas bubbles via the torn RVOT. Although a CO2 blower is useful to enhance visualization of the anastomosis during OPCAB, it should not be used for the venous system because it may cause CO2 embolism.

  17. Thermocapillary Flow and Aggregation of Bubbles on a Solid Wall

    Science.gov (United States)

    Kasumi, Hiroki; Solomentsev, Yuri E.; Guelcher, Scott A.; Anderson, John L.; Sides, Paul J.

    2000-01-01

    During the electrolytic evolution of oxygen bubbles forming on a vertically oriented transparent tin oxide electrode, bubbles were found to be mutually attractive. The mechanism of the aggregation had never been explained satisfactorily until Guelcher et al. attributed it to thermocapillary flow. The gradient of surface tension of the liquid at the bubble's surface, which was established because of reaction heat and ohmic heat loss at the electrode wall, drives flow of the liquid adjacent to each bubble; the bubble "pumps" fluid along its surface away from the wall. Fluid flows toward the bubble to conserve mass and entrains nearby bubbles in the flow pattern. The same logic would apply when two bubbles of equal size are adjacent to each other on a warm wall. Each bubble drives thermocapillary flow and hence entrains the other in its flow pattern, which drives the aggregation. Our objective here is to perform experiments where the temperature gradient at the wall is well known and controlled. The theory can be quantitatively tested by studying aggregation of bubble pairs of equal size, and by varying system parameters such as temperature gradient, bubble size and fluid viscosity. The results are then compared with the theory in a quantitatively rigorous manner. We demonstrate that the theory without adjustable parameters is capable of quantitatively modeling the rate of aggregation of two bubbles. The equations governing the thermocapillary flow around a single stationary bubble on a heated or cooled wall in a semi-infinite domain were solved. Both Reynolds number and Marangoni number were much less than unity. The critical result is that liquid in the vicinity of a warm wall flows toward a stationary collector bubble. Consequently the thermocapillary flow around the stationary bubble entrains another bubble toward itself. The bubbles undergo hindered translation parallel to the wall with velocity U while the fluid flow field is described with u. Two velocities

  18. Heat pumps

    CERN Document Server

    Macmichael, DBA

    1988-01-01

    A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

  19. Multivariate bubbles and antibubbles

    Science.gov (United States)

    Fry, John

    2014-08-01

    In this paper we develop models for multivariate financial bubbles and antibubbles based on statistical physics. In particular, we extend a rich set of univariate models to higher dimensions. Changes in market regime can be explicitly shown to represent a phase transition from random to deterministic behaviour in prices. Moreover, our multivariate models are able to capture some of the contagious effects that occur during such episodes. We are able to show that declining lending quality helped fuel a bubble in the US stock market prior to 2008. Further, our approach offers interesting insights into the spatial development of UK house prices.

  20. Fermi Bubbles with HAWC

    OpenAIRE

    Solares, H. A. Ayala; Hui, C. M.; Hüntemeyer, P.; collaboration, for the HAWC

    2015-01-01

    The Fermi Bubbles, which comprise two large and homogeneous regions of spectrally hard gamma-ray emission extending up to $55^{o}$ above and below the Galactic Center, were first noticed in GeV gamma-ray data from the Fermi Telescope in 2010. The mechanism or mechanisms which produce the observed hard spectrum are not understood. Although both hadronic and lep- tonic models can describe the spectrum of the bubbles, the leptonic model can also explain similar structures observed in microwave d...

  1. 14 CFR 25.991 - Fuel pumps.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel pumps. 25.991 Section 25.991... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.991 Fuel pumps. (a) Main pumps. Each fuel pump required for proper engine operation, or required to meet the fuel...

  2. METHOD FOR OPTIMIZING THE ENERGY OF PUMPS

    NARCIS (Netherlands)

    Skovmose Kallesøe, Carsten; De Persis, Claudio

    2013-01-01

    The device for energy-optimization on operation of several centrifugal pumps controlled in rotational speed, in a hydraulic installation, begins firstly with determining which pumps as pilot pumps are assigned directly to a consumer and which pumps are hydraulically connected in series upstream of t

  3. Lunar Base Heat Pump

    Science.gov (United States)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  4. Annual Summary Report Calendar Year 2000 for the 100-HR-3, 100-KR-4, and 100-NR-2 Operable Units and Pump-and-Treat Operations

    Energy Technology Data Exchange (ETDEWEB)

    G. B. Mitchem

    2001-08-22

    This annual progress and performance evaluation report discusses the groundwater remedial actions in the 100 Area, including the interim actions at the 100-HR-3 and 100-KR-4 Operable Units, and also discusses the expedited response action in the 100-NR-2 operable unit.

  5. The Early Years: Blowing Bubbles

    Science.gov (United States)

    Ashbrook, Peggy

    2016-01-01

    Blowing bubbles is not only a favorite summer activity for young children. Studying bubbles that are grouped together, or "foam," is fun for children and fascinating to many real-world scientists. Foam is widely used--from the bedroom (mattresses) to outer space (insulating panels on spacecraft). Bubble foam can provide children a…

  6. Understanding the bubbles

    DEFF Research Database (Denmark)

    Turcan, Romeo V.

    that are identified to exist between the Internet and housing market bubbles: uncertainty and sentiments. The iteration between uncertainty and sentiments leads to the emergence of the third commonality: residue. The residue is the difference between the actors’ overall sentiment about exaggerated future prospects...

  7. Heavy liquid bubble chamber

    CERN Multimedia

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  8. The Liberal Arts Bubble

    Science.gov (United States)

    Agresto, John

    2011-01-01

    The author expresses his doubt that the general higher education bubble will burst anytime soon. Although tuition, student housing, and book costs have all increased substantially, he believes it is still likely that the federal government will continue to pour billions into higher education, largely because Americans have been persuaded that it…

  9. Popping the Bubble

    Institute of Scientific and Technical Information of China (English)

    LAN XINZHEN

    2010-01-01

    @@ Amid concerns surrounding the presence of housing bubbles across China,the Chinese Government is taking action to secure and stabilize the real estate market.In the past month,the government launched a series of regulatory policies aimed at cooling the overheated market.

  10. BEBC bubble chamber

    CERN Multimedia

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  11. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  12. 风电与抽水蓄能联合优化运行%Optimization Operation of Wind Power and Pumped Storage

    Institute of Scientific and Technical Information of China (English)

    赵诗雅; 常帅; 王仕龙; 杨培培

    2015-01-01

    Pumped storage power combined power plant and wind farm operation not only can better meet the needs of actual load,but also get more substantial economic benefits.Considering reservoir capacity and unit start stop and the fluc-tuation of electricity price and other constraints,the economy and stability of the target of joint optimal operation mode with wind power and pumped storage is proposed in this article.In order to verify the feasibility of the mode,genetic algorithm is used to solve the problem of practical examples.The simulation results show that the established model and the feasibili-ty and effectiveness of the algorithm.%抽水蓄能电站与风电场联合运行不仅能够较好地满足实际负荷的需求,还能获得更丰厚的经济效益。在考虑水库容量、机组启停以及波动电价等约束条件前提下,文中提出以经济性和稳定性为目标的风电与抽水蓄能联合优化运行模式。为验证所建模式可行,采用遗传算法对实际生活中的算例进行求解,仿真分析结果表明:所建的模型和所用算法是可行和有效的。

  13. Research on heat pumps in Mexico operating with geothermal energy and waste heat; Investigacion sobre bombas de calor en Mexico operando con energia geotermica y calor de desecho

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gutierrez, A; Barragan-Reyes, R.M; Arellano-Gomez, V [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx

    2008-01-15

    The Instituto de Investigaciones Electricas and the Comision Federal de Electricidad have done research and development (R&D) on heat pumps (HP) in past years. Tested systems include mechanical compression, absorption and heat-transformers. The main R&D aspects on HP are briefly described, and also a more detailed description about three of the main studies is presented: (a) a mechanical compression HP of the water-water type operated with low-pressure geothermal steam at the Los Azufres; Mich., geothermal field, and designed for purification of brine; (b) an absorption HP for cooling and refrigeration operating with ammonia-water and low-enthalpy geothermal energy, which was tested in the Los Azufres and Cerro Prieto, BC, geothermal fields; and (c) a heat-transformer by absorption-Absorption Heat Pump Type II-tested to assess the performance of several ternary solutions as work fluids. Plans exist to install and test a geothermal heat pump at Cerro Prieto or Mexicali, BC. [Spanish] El Instituto de Investigaciones Electricas y la Comision Federal de Electricidad han realizado trabajo de investigacion y desarrollo (I&D) sobre bombas de calor (BC) en el pasado. Los sistemas probados incluyen compresion mecanica, absorcion y transformadores termicos. Este trabajo describe brevemente los principales aspectos de I&D sobre bombas de calor en forma general, y se da una descripcion mas detallada de tres de los principales estudios: (a) una BC por compresion mecanica tipo agua-agua disenada para purificacion de salmueras operando con vapor geotermico de baja presion en el campo geotermico de Los Azufres, Mich.; (b) una BC por absorcion para enfriamiento y refrigeracion operando con amoniaco-agua y energia geotermica de baja entalpia, la cual fue probada en los campos geotermicos de Los Azufres y Cerro Prieto, BC; y (c) un transformador termico por absorcion -llamado Bomba de Calor por Absorcion Tipo II--, el cual fue probado para evaluar el comportamiento de diversas

  14. Characteristics of bubble plumes, bubble-plume bubbles and waves from wind-steepened wave breaking

    NARCIS (Netherlands)

    Leifer, I.; Caulliez, G.; Leeuw, G. de

    2007-01-01

    Observations of breaking waves, associated bubble plumes and bubble-plume size distributions were used to explore the coupled evolution of wave-breaking, wave properties and bubble-plume characteristics. Experiments were made in a large, freshwater, wind-wave channel with mechanical wind-steepened w

  15. Bubble properties of heterogeneous bubbly flows in a square bubble column: draft

    NARCIS (Netherlands)

    Bai, Wei; Deen, Niels G.; Kuipers, J.A.M.

    2009-01-01

    The present work focuses on the measurements of bubble properties in heterogeneous bubbly flows in a square bubble column. A four-point optical fibre probe was used for this purpose. The accuracy and intrusive effect of the optical probe was investigated first. The results show that the optical prob

  16. Bubble dynamics and bubble-induced turbulence of a single-bubble chain

    Science.gov (United States)

    Lee, Joohyoung; Park, Hyungmin

    2016-11-01

    In the present study, the bubble dynamics and liquid-phase turbulence induced by a chain of bubbles injected from a single nozzle have been experimentally investigated. Using a high-speed two-phase particle image velociemtry, measurements on the bubbles and liquid-phase velocity field are conducted in a transparent tank filled with water, while varying the bubble release frequency from 0.1 to 35 Hz. The tested bubble size ranges between 2.0-3.2 mm, and the corresponding bubble Reynolds number is 590-1100, indicating that it belongs to the regime of path instability. As the release frequency increases, it is found that the global shape of bubble dispersion can be classified into two regimes: from asymmetric (regular) to axisymmetric (irregular). In particular, at higher frequency, the wake vortices of leading bubbles cause an irregular behaviour of the following bubble. For the liquid phase, it is found that a specific trend on the bubble-induced turbulence appears in a strong relation to the above bubble dynamics. Considering this, we try to provide a theoretical model to estimate the liquid-phase turbulence induced by a chain of bubbles. Supported by a Grant funded by Samsung Electronics, Korea.

  17. Bubbles generated from wind-steepened breaking waves: 1. Bubble plume bubbles

    NARCIS (Netherlands)

    Leifer, I.; Leeuw, G. de

    2006-01-01

    Measurements of bubble plumes from paddle-amplified, wind stress breaking waves were made in a large wind-wave channel during the LUMINY experiment in fresh (but not clean) water. Bubble plumes exhibited considerable variability with respect to dynamics, bubble size distribution, and physical

  18. Bubble properties of heterogeneous bubbly flow in a square bubble column

    NARCIS (Netherlands)

    Bai, W.; Deen, N.G.; Kuipers, J.A.M.

    2010-01-01

    The present work focuses on the measurements of bubble properties in heterogeneous bubbly flows in a square bubble column. A four-point optical fibre probe was used for this purpose. The accuracy and intrusive effect of the optical probe was investigated first. The results show that the optical prob

  19. Bubbles generated from wind-steepened breaking waves: 1. Bubble plume bubbles

    NARCIS (Netherlands)

    Leifer, I.; Leeuw, G. de

    2006-01-01

    Measurements of bubble plumes from paddle-amplified, wind stress breaking waves were made in a large wind-wave channel during the LUMINY experiment in fresh (but not clean) water. Bubble plumes exhibited considerable variability with respect to dynamics, bubble size distribution, and physical extent

  20. Optimization design and effect analysis of multi-operation conditions of axial-flow pump device%轴流泵多工况优化设计及效果分析

    Institute of Scientific and Technical Information of China (English)

    石丽建; 汤方平; 刘超; 谢荣盛; 谢传流; 孙丹丹

    2016-01-01

    The flow units of pump device will produce a bad flow regime when the axial-flow pump runs under off-design condition. The paper uses the numerical simulation and numerical optimization techniques, changes the geometric design parameters of axial-flow impeller, and carries out the optimization design of multi-operation conditions of axial-flow pump device. The optimization design based on pump device experiment analysis aims to improve the efficiency of operation under off-design conditions, broaden the scope of the efficiency of pump device, and reduce the operating cost of pump station. Firstly, this paper performs the parametric modeling of axial-flow impeller, and uses fewer design parameters to control the shape of pump blades by FORTRAN. According to the design condition to design an axial-flow impeller with high efficiency, and design the guide vane based on the design condition and the impeller. Use the impeller, the guide vane, and the standard inlet and outlet pipe to calculate the hydraulic performance of axial-flow pump device. Then do the experiment of the pump device to verify the accuracy and reliability of the numerical simulation of the pump device. Lastly, this paper carries out the optimization design of multi-operation conditions of axial-flow pump device. The design flow is 360 L/s, the small flow is 300 L/s and the large flow is 420 L/s, and the 3 flow conditions is chosen as the multi-operation conditions. Change the design parameters of axial-flow impeller, select the weighted average efficiency of pump device as the optimization object and the head of each condition as the constraint, and carry out the optimization design of multi-operation conditions of axial-flow pump device. For each design parameter, every change corresponds to a complete numerical simulation of pump device. Last but not least, this article does the internal flow field analysis of pump before and after optimization. The analysis mainly includes the streamline comparison

  1. Mechanics of Bubbles in Sludges and Slurries Modeling Studies of Particulate Materials

    Energy Technology Data Exchange (ETDEWEB)

    Phillip A. Gauglitz; Guillermo Terrones; Susan J. Muller; Morton M. Denn; William R. Rossen

    2002-01-07

    The Hanford Site has 177 underground waste storage tanks that are known to retain and release bubbles composed of flammable gases. Characterizing and understanding the behavior of these bubbles is important for the safety issues associated with the flammable gases for both ongoing waste storage and future waste-retrieval operations. The retained bubbles are known to respond to small barometric pressure changes, though in a complex manner with unusual hysteresis occurring in some tanks in the relationship between bubble volume and pressure, or V-P hysteresis. With careful analysis, information on the volume of retained gas and the interactions of the waste and the bubbles can be determined.

  2. In situ X-ray tomographic microscopy observations of vesiculation of bubble-free and bubble-bearing magmas

    Science.gov (United States)

    Pistone, Mattia; Caricchi, Luca; Fife, Julie L.; Mader, Kevin; Ulmer, Peter

    2015-12-01

    Magma degassing is thought to play a major role in magma fractionation, transport, storage, and volcanic eruption dynamics. However, the conditions that determine when and how magma degassing operates prior to and during an eruption remain poorly constrained. We performed experiments to explore if the initial presence of gas bubbles in magma influences the capability of gas to escape from the magma. Vesiculation of natural H2O-poor (bubble coalescence during vesiculation. In both sets of experiments, vesiculation was triggered by heating the samples at room pressure. Our results suggest that the presence of pre-existing gas bubbles during a nucleation event significantly decreases the tendency of bubbles to coalesce and inhibits magma outgassing. In contrast, in initially bubble-free samples, the nucleation and growth of bubbles is accompanied by significant coalescence and outgassing. We infer that volatile-undersaturated (i.e. bubble-free) magmas in the reservoirs are more likely to erupt effusively, while the presence of excess gas already at depth (i.e. bubble-bearing systems) increases the likelihood of explosive eruptions.

  3. Saving energy by optimized operation. Making use of saving potentials: Software solutions for design of pumps, armatures and pipelines; Mit dem richtigen Betriebspunkt Energie sparen. Sparpotenziale nutzen. Softwareloesungen zur Auslegung von Pumpen, Armaturen und Rohrleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Jens-Uwe [VSX - VOGEL SOFTWARE GmbH, Dresden (Germany)

    2011-07-01

    Attempts to save energy included hydraulic optimization of aggregates and the development of new, high-efficiency electric drives and control systems. On the other hand, the saving potential of correct pipeline dimensioning in the planning phase and optimisation of operation is often underestimated. Correct design is a key element of efficient pump operation. Web-based planning tools can help. The new Spaix PipeCalc by VSX - VOGEL SOFTWARE is a calculation program for unbranched pipelines that was designed as an optimum supplement to pump design software.

  4. A Micro-PIV Study of the Pulsed Micro-Flows Driven by an Insulin Pump

    Science.gov (United States)

    Wang, Bing; Demuren, Ayodeji; Gyuricsko, Eric; Hu, Hui

    2009-11-01

    In recent years, there is a surge in the popularity of using insulin pump or continuous subcutaneous insulin infusion therapy, as opposed to multiple daily injections by insulin syringe or an insulin pen. Some case studies have suggested that insulin delivery failure may be caused by precipitation of insulin within the infusion set. Speculation also exists that the flow of insulin through an insulin infusion set may be reduced or inhibited by air bubbles entrained into the micro-sized tubing system since there are chances that air be introduced into the insulin reservoir during the filling process. In the present study, a microscopic Particle Image Velocimtry (micro-PIV) system was used to characterize the transient behavior of the pulsed micro-flows inside the micro-sized tubing system of an insulin infusion set with insulin pump operating in basal mode (i.e., pulsed insulin pumping). The effects of the air bubbles entrained into the micro-sized tubing system on the insulin delivery process were assessed based on the micro-PIV measurements.

  5. Bubble Dynamics and Shock Waves

    CERN Document Server

    2013-01-01

    This volume of the Shock Wave Science and Technology Reference Library is concerned with the interplay between bubble dynamics and shock waves. It is divided into four parts containing twelve chapters written by eminent scientists. Topics discussed include shock wave emission by laser generated bubbles (W Lauterborn, A Vogel), pulsating bubbles near boundaries (DM Leppinen, QX Wang, JR Blake), interaction of shock waves with bubble clouds (CD Ohl, SW Ohl), shock propagation in polydispersed bubbly liquids by model equations (K Ando, T Colonius, CE Brennen. T Yano, T Kanagawa,  M Watanabe, S Fujikawa) and by DNS (G Tryggvason, S Dabiri), shocks in cavitating flows (NA Adams, SJ Schmidt, CF Delale, GH Schnerr, S Pasinlioglu) together with applications involving encapsulated bubble dynamics in imaging (AA Doinikov, A Novell, JM Escoffre, A Bouakaz),  shock wave lithotripsy (P Zhong), sterilization of ships’ ballast water (A Abe, H Mimura) and bubbly flow model of volcano eruptions ((VK Kedrinskii, K Takayama...

  6. Rigorous buoyancy driven bubble mixing for centrifugal microfluidics.

    Science.gov (United States)

    Burger, S; Schulz, M; von Stetten, F; Zengerle, R; Paust, N

    2016-01-21

    We present batch-mode mixing for centrifugal microfluidics operated at fixed rotational frequency. Gas is generated by the disk integrated decomposition of hydrogen peroxide (H2O2) to liquid water (H2O) and gaseous oxygen (O2) and inserted into a mixing chamber. There, bubbles are formed that ascent through the liquid in the artificial gravity field and lead to drag flow. Additionaly, strong buoyancy causes deformation and rupture of the gas bubbles and induces strong mixing flows in the liquids. Buoyancy driven bubble mixing is quantitatively compared to shake mode mixing, mixing by reciprocation and vortex mixing. To determine mixing efficiencies in a meaningful way, the different mixers are employed for mixing of a lysis reagent and human whole blood. Subsequently, DNA is extracted from the lysate and the amount of DNA recovered is taken as a measure for mixing efficiency. Relative to standard vortex mixing, DNA extraction based on buoyancy driven bubble mixing resulted in yields of 92 ± 8% (100 s mixing time) and 100 ± 8% (600 s) at 130g centrifugal acceleration. Shake mode mixing yields 96 ± 11% and is thus equal to buoyancy driven bubble mixing. An advantage of buoyancy driven bubble mixing is that it can be operated at fixed rotational frequency, however. The additional costs of implementing buoyancy driven bubble mixing are low since both the activation liquid and the catalyst are very low cost and no external means are required in the processing device. Furthermore, buoyancy driven bubble mixing can easily be integrated in a monolithic manner and is compatible to scalable manufacturing technologies such as injection moulding or thermoforming. We consider buoyancy driven bubble mixing an excellent alternative to shake mode mixing, in particular if the processing device is not capable of providing fast changes of rotational frequency or if the low average rotational frequency is challenging for the other integrated fluidic operations.

  7. Pump Application as Hydraulic Turbine – Pump as Turbine (PaT)

    OpenAIRE

    Rusovs, D

    2009-01-01

    The paper considers pump operation as hydraulic turbine with purpose to produce mechanical power from liquid flow. The Francis hydraulic turbine was selected for comparison with centrifugal pump in reverse operation. Turbine and centrifugal pump velocity triangles were considered with purpose to evaluate PaT efficiency. Shape of impeller blades for turbine and pumps was analysed. Specific speed calculation is carried out with purpose to obtain similarity in pump and turbine description. For ...

  8. A Magnetically Coupled Cryogenic Pump

    Science.gov (United States)

    Hatfield, Walter; Jumper, Kevin

    2011-01-01

    Historically, cryogenic pumps used for propellant loading at Kennedy Space Center (KSC) and other NASA Centers have a bellows mechanical seal and oil bath ball bearings, both of which can be problematic and require high maintenance. Because of the extremely low temperatures, the mechanical seals are made of special materials and design, have wearing surfaces, are subject to improper installation, and commonly are a potential leak path. The ball bearings are non-precision bearings [ABEC-1 (Annular Bearing Engineering Council)] and are lubricated using LOX compatible oil. This oil is compatible with the propellant to prevent explosions, but does not have good lubricating properties. Due to the poor lubricity, it has been a goal of the KSC cryogenics community for the last 15 years to develop a magnetically coupled pump, which would eliminate these two potential issues. A number of projects have been attempted, but none of the pumps was a success. An off-the-shelf magnetically coupled pump (typically used with corrosive fluids) was procured that has been used for hypergolic service at KSC. The KSC Cryogenics Test Lab (CTL) operated the pump in cryogenic LN2 as received to determine a baseline for modifications required. The pump bushing, bearings, and thrust rings failed, and the pump would not flow liquid (this is a typical failure mode that was experienced in the previous attempts). Using the knowledge gained over the years designing and building cryogenic pumps, the CTL determined alternative materials that would be suitable for use under the pump design conditions. The CTL procured alternative materials for the bearings (bronze, aluminum bronze, and glass filled PTFE) and machined new bearing bushings, sleeves, and thrust rings. The designed clearances among the bushings, sleeves, thrust rings, case, and case cover were altered once again using experience gained from previous cryogenic pump rebuilds and designs. The alternative material parts were assembled into

  9. Experimental Realization of a Quantum Spin Pump

    DEFF Research Database (Denmark)

    Watson, Susan; Potok, R.; M. Marcus, C.;

    2003-01-01

    We demonstrate the operation of a quantum spin pump based on cyclic radio-frequency excitation of a GaAs quantum dot, including the ability to pump pure spin without pumping charge. The device takes advantage of bidirectional mesoscopic fluctuations of pumped current, made spin......-dependent by the application of an in-plane Zeeman field. Spin currents are measured by placing the pump in a focusing geometry with a spin-selective collector....

  10. Dark matter searches with PICO bubble chambers: An overview

    Science.gov (United States)

    Harris, Orin; PICO Collaboration

    2017-01-01

    The PICO collaboration uses bubble chambers to search for dark matter, with world-leading sensitivity to the direct-detection of WIMPs with spin-dependent couplings to protons. PICO currently operates a 2 liter (PICO-2L) and a 32 liter (PICO 60) bubble chamber at the SNOLAB deep underground laboratory, and is currently constructing a 40 liter demonstration device that is expected to eliminate an anomalous background that has previously proven significant for the scaling of the bubble chamber technique to a future ton-scale experiment (PICO-500). A discussion of the technology, recent progress, and future plans will be presented.

  11. Study of a pilot photovoltaic-electrolyser-fuel cell power system for a geothermal heat pump heated greenhouse and evaluation of the electrolyser efficiency and operational mode

    Directory of Open Access Journals (Sweden)

    Ileana Blanco

    2014-11-01

    Full Text Available The intrinsic factor of variability of renewable energy sources often limits their broader use. The photovoltaic solar systems can be provided with a power back up based on a combination of an electrolyser and a fuel cell stack. The integration of solar hydrogen power systems with greenhouse heating equipment can provide a possible option for powering stand-alone greenhouses. The aim of the research under development at the experimental farm of Department of Agro-Environmental Sciences of the University of Bari Aldo Moro is to investigate on the suitable solutions of a power system based on photovoltaic energy and on the use of hydrogen as energy vector, integrated with a ground source heat pump for greenhouse heating in a self sustained way. The excess energy produced by a purpose-built array of solar photovoltaic modules supplies an alkaline electrolyser; the produced hydrogen gas is stored in pressured storage tank. When the solar radiation level is insufficient to meet the heat pump power demand, the fuel cell starts converting the chemical energy stored by the hydrogen fuel into electricity. This paper reports on the description of the realised system. Furthermore the efficiency and the operational mode of the electrolyser were evaluated during a trial period characterised by mutable solar radiant energy. Anyway the electrolyser worked continuously in a transient state producing fluctuations of the hydrogen production and without ever reaching the steady-state conditions. The Faradic efficiency, evaluated by means of an empirical mathematic model, highlights that the suitable working range of the electrolyser was 1.5÷2.5 kW and then for hydrogen production more than 0.21 Nm3h–1.

  12. Bubble colloidal AFM probes formed from ultrasonically generated bubbles.

    Science.gov (United States)

    Vakarelski, Ivan U; Lee, Judy; Dagastine, Raymond R; Chan, Derek Y C; Stevens, Geoffrey W; Grieser, Franz

    2008-02-05

    Here we introduce a simple and effective experimental approach to measuring the interaction forces between two small bubbles (approximately 80-140 microm) in aqueous solution during controlled collisions on the scale of micrometers to nanometers. The colloidal probe technique using atomic force microscopy (AFM) was extended to measure interaction forces between a cantilever-attached bubble and surface-attached bubbles of various sizes. By using an ultrasonic source, we generated numerous small bubbles on a mildly hydrophobic surface of a glass slide. A single bubble picked up with a strongly hydrophobized V-shaped cantilever was used as the colloidal probe. Sample force measurements were used to evaluate the pure water bubble cleanliness and the general consistency of the measurements.

  13. Nuclear-pumped lasers

    CERN Document Server

    Prelas, Mark

    2016-01-01

    This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....

  14. CRISIS FOCUS Blowing Bubbles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Chinese stock and property markets have been outperforming expectations, fueled by an unprecedented surge in bank lending. Xie Guozhong, an economist and board member of Rosetta Stone Advisors, argues the robust Chinese economic figures are only propped up by bubbles, whose bursting will lead to a hard landing for the economy. Xie published his opinion in a related article in Caijing Magazine. Edited excerpts follow:

  15. Bubble performance of a novel dissolved air flotation(DAF) unit

    Institute of Scientific and Technical Information of China (English)

    CHEN Fu-tai; PENG Feng-xian; WU Xiao-qing; LUAN Zhao-kun

    2004-01-01

    ES-DAF, a novel DAF with Iow cost, high reliability and easy controllability, was studied. Without a costly air saturator, ESDAF consists of an ejector and a static mixer between the pressure side and suction side of the recycle rotary pump. The bubble size distribution in this novel unit was studied in detail by using a newly developed CCD imagination through a microscope. Compared with MDAF under the same saturation pressure, ES-DAF can produce smaller bubble size and higher bubble volume concentration, especially in lower pressure. In addition, the bubble size decreases with the increase of reflux ratio or decrease of superficial air-water ratio. These results suggested that smaller bubbles will be formed when the initial number of nucleation sites increases by enhancing the turbulence intensity in the saturation system.

  16. Study of motor-pump operating as generator groups in hydroelectric micro hydropower plants; Estudo de grupos moto-bomba operando como grupos geradores em microcentrais hidreletricas

    Energy Technology Data Exchange (ETDEWEB)

    Ricardo, Mateus

    2007-07-01

    The present work aims to evaluate the in site use of pumps working as turbines (PATs) and induction engines operating as generators (MIGs), for the replacement of conventional generating groups in micro hydropower plants (MHPs), focusing on PATs. To achieve this goal, a case study was accomplished on a micro hydropower plant installed in Mantiqueira Mountain that, after been rebuilt, received a PAT/MIG generating group. It's a pioneer research, being the first documented case of implementation of PATs and MIGs in a real MHP in Brazil. After tests for defining the efficiency, and the comparison with theoretical and laboratory results, it was concluded that PAT/MIG generating groups can be used effectively in electricity generation, by the application of appropriate selection methodologies and adjustments to optimize its operation in reverse. Besides the technical aspects, it was also addressed the technology's economic aspects. Through prices research and costs composition, it was possible to quantify the economic benefit of PAT/MIG groups over conventional generating groups, noting that the studied technology reduces the micro hydropower plants deployment costs in a significant way . (author)

  17. Study on the Optimizing Operation of Exhaust Air Heat Recovery and Solar Energy Combined Thermal Compensation System for Ground-Coupled Heat Pump

    Directory of Open Access Journals (Sweden)

    Kuan Wang

    2017-01-01

    Full Text Available This study proposed an exhaust air heat recovery and solar energy combined thermal compensation system (ESTC for ground-coupled heat pumps. Based on the prediction of the next day’s exhaust air temperature and solar irradiance, an optimized thermal compensation (OTC method was developed in this study as well, in which the exhaust air heat recovery compensator and solar energy compensator in the ESTC system run at high efficiency throughout various times of day. Moreover, a modified solar term similar days group (STSDG method was proposed to improve the accuracy of solar irradiance prediction in hazy weather. This modified STSDG method was based on air quality forecast and AQI (air quality index correction factors. Through analyzing the operating parameters and the simulation results of a case study, the ESTC system proved to have good performance and high efficiency in eliminating the heat imbalance by using the OTC method. The thermal compensation quantity per unit energy consumption (TEC of ESTC under the proposed method was 1.25 times as high as that under the traditional operation method. The modified STSDG method also exhibited high accuracy. For the accumulated solar irradiance of the four highest daily radiation hours, the monthly mean absolute percentage error (MAPE between the predicted values and the measured values was 6.35%.

  18. Development and application of paraffin removal unit in pump detection operation%检泵清蜡装置的开发与应用

    Institute of Scientific and Technical Information of China (English)

    单朝新; 赵明凯

    2001-01-01

    Wax removal is very important work in pump detection operation. Regular wax removal technology has many disadvantages. It can' t meet the requirements of operation progress and limitation period at present. Through research on the law and properties of oil well wax precipitation in Thha Oilfield, tight paraffin removal units of sucker rod and tubing are developed. The paraffin removal units has many advantages,such as high thermal efficiency, short expend time, low labour strength and unpollution etc.. By field practice and application of the paraffin removal units, better results are got.%清蜡是检泵作业中一项重要工作,常规清蜡工艺过程存在诸多弊端,越来越不适应日益提高的作业进度和时效的要求。通过对吐哈油田油井结蜡规律及结蜡特性的研究,结合生产实际,开发出的抽油杆密闭清蜡装置和油管立柱清蜡装置,具有热效率高、耗时短、劳动强度低、不污染、占地面积小等优点。通过现场的实施与应用,取得了良好的效果。

  19. Electromagnetically powered electrolytic pump and thermo-responsive valve for drug delivery

    KAUST Repository

    Yi, Ying

    2015-04-01

    A novel drug delivery device is presented, implementing an electrolytic pump and a thermo-responsive valve. The device is remotely operated by an AC electromagnetic field (40.5∼58.5 mT, 450 kHz) that provides the power for the pump and the valve. It is suitable for long-term therapy applications, which use a solid drug in reservoir (SDR) approach and avoids unwanted drug diffusion. When the electromagnetic field is on, the electrolytic pump drives the drug towards the valve. The valve is made of a magnetic composite consisting of a smart hydrogel: Poly (N-Isopropylacrylamide) (PNIPAm) and iron powder. The heat generated in the iron powder via magnetic losses causes the PNIPAm to shrink, allowing the drug to flow past it. When the electromagnetic field is off, the PNIPAm swells, sealing the outlet. In the meantime, the bubbles generated by electrolysis recombine into water, causing a pressure reduction in the pumping chamber. This draws fresh fluid from outside the pump into the drug reservoir before the valve is fully sealed. The recombination can be accelerated by a platinum (Pt) coated catalytic reformer, allowing more fluid to flow back to the drug reservoir and dissolve the drug. By repeatedly turning on and off the magnetic field, the drug solution can be delivered cyclically. © 2015 IEEE.

  20. Shrinking equatorial plasma bubbles

    Science.gov (United States)

    Narayanan, V. L.; Gurubaran, S.; Shiokawa, K.; Emperumal, K.

    2016-07-01

    The formation of equatorial plasma bubbles (EPBs) associated with spread F irregularities are fairly common phenomenon in the postsunset equatorial ionosphere. These bubbles grow as a result of eastward polarization electric field resulting in upward E × B drift over the dip equator. As they grow they are also mapped to low latitudes along magnetic field lines. The EPBs are often observed as airglow depletions in the images of OI 630 nm emission. On occasions the growth of the features over the dip equator is observed as poleward extensions of the depletions in all-sky images obtained from low latitudes. Herein, we present interesting observations of decrease in the latitudinal extent of the EPBs corresponding to a reduction in their apex altitudes over the dip equator. Such observations indicate that these bubbles not only grow but also shrink on occasions. These are the first observations of shrinking EPBs. The observations discussed in this work are based on all-sky airglow imaging observations of OI 630.0 nm emission made from Panhala (11.1°N dip latitude). In addition, ionosonde observations made from dip equatorial site Tirunelveli (1.1°N dip latitude) are used to understand the phenomenon better. The analysis indicates that the speed of shrinking occurring in the topside is different from the bottomside vertical drifts. When the EPBs shrink, they might decay before sunrise hours.

  1. Optical measurements of gas bubbles in oil behind a cavitating micro-orifice flow

    Science.gov (United States)

    Iben, Uwe; Wolf, Fabian; Freudigmann, Hans-Arndt; Fröhlich, Jochen; Heller, Winfried

    2015-06-01

    In hydraulic systems, it is common for air release to occur behind valves or throttles in the form of bubbles. These air bubbles can affect the behavior and the performance of these systems to a substantial extent. In the paper, gas release in a liquid flow behind an orifice is analyzed by optical methods for various operation points. The bubbles are observed with a digital camera, and a detection algorithm based on the Hough transformation is used to determine their number and size. The appearance of gas bubbles is very sensitive to the inlet and outlet pressure of the orifice. Gas bubbles are only observed if choking cavitation occurs. An empirical relationship between an adjusted cavitation number and the appearance of gas release is presented. It is assumed that the observed bubbles contain mostly air. With the applied pressure differences, up to 30 % of the dissolved air was degassed in the form of bubbles.

  2. Effect of operating parameters on production of bio-oil from fast pyrolysis of maize stalk in bubbling fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    Ali Najaf

    2016-09-01

    Full Text Available The yield and composition of pyrolysis products depend on the characteristics of feed stock and process operating parameters. Effect of particle size, reaction temperature and carrier gas flow rate on the yield of bio-oil from fast pyrolysis of Pakistani maize stalk was investigated. Pyrolysis experiments were performed at temperature range of 360-540°C, feed particle size of 1-2 mm and carrier gas fl ow rate of 7.0-13.0 m3/h (0.61.1 m/s superficial velocity. Bio-oil yield increased with the increase of temperature followed by a decreasing trend. The maximum yield of bio-oil obtained was 42 wt% at a temperature of 490°C with the particle size of around 1.0 mm and carrier gas flow rate of 11.0 m3/h (0.9 m/s superficial velocity. High temperatures resulted in the higher ratios of char and non-condensable gas.

  3. Ferroelectric Pump

    Science.gov (United States)

    Jalink, Antony, Jr. (Inventor); Hellbaum, Richard F. (Inventor); Rohrbach, Wayne W. (Inventor)

    2000-01-01

    A ferroelectric pump has one or more variable volume pumping chambers internal to a housing. Each chamber has at least one wall comprising a dome shaped internally prestressed ferroelectric actuator having a curvature and a dome height that varies with an electric voltage applied between an inside and outside surface of the actuator. A pumped medium flows into and out of each pumping chamber in response to displacement of the ferroelectric actuator. The ferroelectric actuator is mounted within each wall and isolates each ferroelectric actuator from the pumped medium, supplies a path for voltage to be applied to each ferroelectric actuator, and provides for positive containment of each ferroelectric actuator while allowing displacement of the entirety of each ferroelectric actuator in response to the applied voltage.

  4. Bubble Formation in Basalt-like Melts

    DEFF Research Database (Denmark)

    Jensen, Martin; Keding, Ralf; Yue, Yuanzheng

    2011-01-01

    The effect of the melting temperature on bubble size and bubble formation in an iron bearing calcium aluminosilicate melt is studied by means of in-depth images acquired by optical microscopy. The bubble size distribution and the total bubble volume are determined by counting the number of bubble...

  5. Bubble Formation in Basalt-like Melts

    DEFF Research Database (Denmark)

    Jensen, Martin; Keding, Ralf; Yue, Yuanzheng

    2011-01-01

    The effect of the melting temperature on bubble size and bubble formation in an iron bearing calcium aluminosilicate melt is studied by means of in-depth images acquired by optical microscopy. The bubble size distribution and the total bubble volume are determined by counting the number of bubbles...

  6. Electrowetting of a soap bubble

    CERN Document Server

    Arscott, Steve

    2013-01-01

    A proof-of-concept demonstration of the electrowetting-on-dielectric of a sessile soap bubble is reported here. The bubbles are generated using a commercial soap bubble mixture - the surfaces are composed of highly doped, commercial silicon wafers covered with nanometre thick films of Teflon. Voltages less than 40V are sufficient to observe the modification of the bubble shape and the apparent bubble contact angle. Such observations open the way to inter alia the possibility of bubble-transport, as opposed to droplet-transport, in fluidic microsystems (e.g. laboratory-on-a-chip) - the potential gains in terms of volume, speed and surface/volume ratio are non-negligible.

  7. Optimal Operation of Intake Water Pumping Station swith Peak-valley Price and Regulation of Clearwells%考虑峰谷电价及清水池调节容积的取水泵站优化调度

    Institute of Scientific and Technical Information of China (English)

    卫晓贤; 刘德有; 黄时峰; 王丰

    2013-01-01

    取水泵站优化运行调度研究对泵站节能具有较好的指导意义.针对取水泵站的工作特点,以取水泵站日运行耗电费最小为目标,考虑峰谷电价及清水池调节容积对取水泵站日运行耗电费的影响,建立了含定速泵或双速泵的取水泵站优化运行调度数学模型,并利用基于动态规划法的求解策略对该数学模型进行了求解.最后通过实例计算结果表明:在原有泵型不变且同等满足供水要求的情况下,该取水泵站采用优化后的运行方案较目前实际的运行方案,可有效地实现充分利用清水池调节容积应对峰谷电价进行错峰运行,泵站运行耗电费可明显降低,这验证了所建立的优化调度数学模型是合理、有效的,对类似的取水泵站节能运行具有良好的指导意义.%Studying the optimal operation of the intake pumping water station has a guiding significance for pump station energy-saving. In regard to the operational characteristics of intake pumping water stations, a model including constant speed or two-speed pumps is applied for the optimal operation of the intake pumping water stations. The model is established with the minimum day total operational cost as objective functioa The effect of peak-valley price and regulation of clearwells on the day total operational cost of the intake pumping water station are taken into consideration in the optimal operation. The model is computed with the method of dynamic planning . Finally, the calculation results of the practical example show that the intake pumping water station after optimal operation can be effectively achieved to run with peak shifting and the full advantage of regulation of clearwells to respond to the peak-valley price in the case of the unchanged types of the original pumps and meeting the requirements of water suppy equally. And the daily total operational cost of the intake pumping water station decreases significantly. This verifies the

  8. Improving electrokinetic microdevice stability by controlling electrolysis bubbles.

    Science.gov (United States)

    Lee, Hwi Yong; Barber, Cedrick; Minerick, Adrienne R

    2014-07-01

    The voltage-operating window for many electrokinetic microdevices is limited by electrolysis gas bubbles that destabilize microfluidic system causing noise and irreproducible responses above ∼3 V DC and less than ∼1 kHz AC at 3 Vpp. Surfactant additives, SDS and Triton X-100, and an integrated semipermeable SnakeSkin® membrane were employed to control and assess electrolysis bubbles from platinum electrodes in a 180 by 70 μm, 10 mm long microchannel. Stabilized current responses at 100 V DC were observed with surfactant additives or SnakeSkin® barriers. Electrolysis bubble behaviors, visualized via video microscopy at the electrode surface and in the microchannels, were found to be influenced by surfactant function and SnakeSkin® barriers. Both SDS and Triton X-100 surfactants promoted smaller bubble diameters and faster bubble detachment from electrode surfaces via increasing gas solubility. In contrast, SnakeSkin® membranes enhanced natural convection and blocked bubbles from entering the microchannels and thus reduced current disturbances in the electric field. This data illustrated that electrode surface behaviors had substantially greater impacts on current stability than microbubbles within microchannels. Thus, physically blocking bubbles from microchannels is less effective than electrode functionalization approaches to stabilize electrokinetic microfluidic systems.

  9. Size distribution of air bubbles entering the brain during cardiac surgery.

    Directory of Open Access Journals (Sweden)

    Emma M L Chung

    Full Text Available Thousands of air bubbles enter the cerebral circulation during cardiac surgery, but whether high numbers of bubbles explain post-operative cognitive decline is currently controversial. This study estimates the size distribution of air bubbles and volume of air entering the cerebral arteries intra-operatively based on analysis of transcranial Doppler ultrasound data.Transcranial Doppler ultrasound recordings from ten patients undergoing heart surgery were analysed for the presence of embolic signals. The backscattered intensity of each embolic signal was modelled based on ultrasound scattering theory to provide an estimate of bubble diameter. The impact of showers of bubbles on cerebral blood-flow was then investigated using patient-specific Monte-Carlo simulations to model the accumulation and clearance of bubbles within a model vasculature.Analysis of Doppler ultrasound recordings revealed a minimum of 371 and maximum of 6476 bubbles entering the middle cerebral artery territories during surgery. This was estimated to correspond to a total volume of air ranging between 0.003 and 0.12 mL. Based on analysis of a total of 18667 embolic signals, the median diameter of bubbles entering the cerebral arteries was 33 μm (IQR: 18 to 69 μm. Although bubble diameters ranged from ~5 μm to 3.5 mm, the majority (85% were less than 100 μm. Numerous small bubbles detected during cardiopulmonary bypass were estimated by Monte-Carlo simulation to be benign. However, during weaning from bypass, showers containing large macro-bubbles were observed, which were estimated to transiently affect up to 2.2% of arterioles.Detailed analysis of Doppler ultrasound data can be used to provide an estimate of bubble diameter, total volume of air, and the likely impact of embolic showers on cerebral blood flow. Although bubbles are alarmingly numerous during surgery, our simulations suggest that the majority of bubbles are too small to be harmful.

  10. Investigation of the interaction dynamics of a pair of laser-induced bubbles generated at the same time through double-exposure strobe method and numerical simulations

    Science.gov (United States)

    Han, Bing; Liu, Liu; Ni, Xiao-Wu

    2017-08-01

    In order to understand the interaction dynamics of a pair of laser-induced bubbles, a double-exposure strobe photography experimental setup is build up to study the temporal evolution of the bubble pairs and to measure the transient bubble-interface moving speed. The interaction mechanisms of the bubble pairs are discussed together with the numerical results obtained through OpenFOAM. It is shown that the direction and the velocity of the jetting could be controlled by the relative size and the relative initiation distance of the bubble pair, when the bubbles are generated at the same time, i.e., in-phase. The liquid jet is considered to be a penetrating jet. The jet is originated from the smaller bubble and clearly protruding outside of the bigger bubble. The parameter space of the relative size and the initiation distance of the bubble pair allowing the formation of the penetrating jet are very narrow. It is concluded that the liquid jet induced by the bubble interactions resulted from the collapse and the rebound of the smaller bubble nearby the bigger bubble. This is defined as the "catapult effect." Such a directional liquid transportation is a promising tool as a micro-injector or a micro-pump. The investigation results could be also supplementary to the understandings of the bubble dynamics.

  11. Experimental investigation of shock wave - bubble interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Mohsen

    2010-04-09

    In this work, the dynamics of laser-generated single cavitation bubbles exposed to lithotripter shock waves has been investigated experimentally. The energy of the impinging shock wave is varied in several steps. High-speed photography and pressure field measurements simultaneously with image acquisition provide the possibility of capturing the fast bubble dynamics under the effect of the shock wave impact. The pressure measurement is performed using a fiber optic probe hydrophone (FOPH) which operates based on optical diagnostics of the shock wave propagating medium. After a short introduction in chapter 1 an overview of the previous studies in chapter 2 is presented. The reported literatures include theoretical and experimental investigations of several configurations of physical problems in the field of bubble dynamics. In chapter 3 a theoretical description of propagation of a shock wave in a liquid like water has been discussed. Different kinds of reflection of a shock wave at an interface are taken into account. Undisturbed bubble dynamics as well as interaction between a planar shock wave and an initially spherical bubble are explored theoretically. Some physical parameters which are important in this issue such as the velocity of the shock-induced liquid jet, Kelvin impulse and kinetic energy are explained. The shock waves are generated in a water filled container by a focusing piezoelectric generator. The shock wave profile has a positive part with pulse duration of ∼1 μs followed by a longer tension tail (i.e. ∼3 μs). In chapter 4 high-speed images depict the propagation of a shock wave in the water filled tank. The maximum pressure is also derived for different intensity levels of the shock wave generator. The measurement is performed in the free field (i.e. in the absence of laser-generated single bubbles). In chapter 5 the interaction between lithotripter shock waves and laserinduced single cavitation bubbles is investigated experimentally. An

  12. Experimental investigation of shock wave - bubble interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Mohsen

    2010-04-09

    In this work, the dynamics of laser-generated single cavitation bubbles exposed to lithotripter shock waves has been investigated experimentally. The energy of the impinging shock wave is varied in several steps. High-speed photography and pressure field measurements simultaneously with image acquisition provide the possibility of capturing the fast bubble dynamics under the effect of the shock wave impact. The pressure measurement is performed using a fiber optic probe hydrophone (FOPH) which operates based on optical diagnostics of the shock wave propagating medium. After a short introduction in chapter 1 an overview of the previous studies in chapter 2 is presented. The reported literatures include theoretical and experimental investigations of several configurations of physical problems in the field of bubble dynamics. In chapter 3 a theoretical description of propagation of a shock wave in a liquid like water has been discussed. Different kinds of reflection of a shock wave at an interface are taken into account. Undisturbed bubble dynamics as well as interaction between a planar shock wave and an initially spherical bubble are explored theoretically. Some physical parameters which are important in this issue such as the velocity of the shock-induced liquid jet, Kelvin impulse and kinetic energy are explained. The shock waves are generated in a water filled container by a focusing piezoelectric generator. The shock wave profile has a positive part with pulse duration of ∼1 μs followed by a longer tension tail (i.e. ∼3 μs). In chapter 4 high-speed images depict the propagation of a shock wave in the water filled tank. The maximum pressure is also derived for different intensity levels of the shock wave generator. The measurement is performed in the free field (i.e. in the absence of laser-generated single bubbles). In chapter 5 the interaction between lithotripter shock waves and laserinduced single cavitation bubbles is investigated experimentally. An

  13. Single-frequency operation of diode-pumped Nd YAG high-power lasers in rod and slab geometry

    CERN Document Server

    Knoke, S

    1998-01-01

    transverse and longitudinal mode is reduced by aberrations of the thermal lens, investigations in the compensation of the thermooptical effects by the laser crystal geometry and the resonator configuration were performed. In addition to the conventional cylindrical rod geometry slab laser crystals with a square cross-section and an internal zig-zag-pass were investigated. Based on the results, the output power of Nd:YAG lasers both in rod and slab geometry could be scaled to more than 20W in single-frequency operation for the first time. A maximum output power of up to 45W was demonstrated with a Nd:YAG rod laser system. Finally principal power limitations of these laser systems could be determined. Laser radiation of high coherence and with diffraction limited beam quality opens up many opportunities for applications in optic metrology, fundamental physics and nonlinear frequency conversion. Light sources with high single-frequency output powers are employed in large Michelson-type interferometers with armle...

  14. Droplets, Bubbles and Ultrasound Interactions.

    Science.gov (United States)

    Shpak, Oleksandr; Verweij, Martin; de Jong, Nico; Versluis, Michel

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to circulate within blood vessels. Perfluorocarbon liquid droplets can be a potential new generation of microbubble agents as ultrasound can trigger their conversion into gas bubbles. Prior to activation, they are at least five times smaller in diameter than the resulting bubbles. Together with the violent nature of the phase-transition, the droplets can be used for local drug delivery, embolotherapy, HIFU enhancement and tumor imaging. Here we explain the basics of bubble dynamics, described by the Rayleigh-Plesset equation, bubble resonance frequency, damping and quality factor. We show the elegant calculation of the above characteristics for the case of small amplitude oscillations by linearizing the equations. The effect and importance of a bubble coating and effective surface tension are also discussed. We give the main characteristics of the power spectrum of bubble oscillations. Preceding bubble dynamics, ultrasound propagation is introduced. We explain the speed of sound, nonlinearity and attenuation terms. We examine bubble ultrasound scattering and how it depends on the wave-shape of the incident wave. Finally, we introduce droplet interaction with ultrasound. We elucidate the ultrasound-focusing concept within a droplets sphere, droplet shaking due to media compressibility and droplet phase-conversion dynamics.

  15. Analysis of bubble pressure in the rim region of high burnup PWR fuel

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Yang Hyun; Lee, Byung Ho; Sohn, Dong Seong [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-02-01

    Bubble pressure in the rim region of high burnup PWR UO{sub 2} fuel has been modeled based on measured rim width, porosity and bubble density. Using the assumption that excessive bubble pressure in the rim is inversely proportional to its radius, proportionality constant is derived as a function of average pellet burnup and bubble radius. This approach is possible because the integration of the number of Xe atoms retained in the rim bubbles, which can be calculated as a function of bubble radius, over the bubble radius gives the total number of Xe atoms in the rim bubbles. Here the total number of Xe atoms in the rim bubbles can be derived from the measured Xe depletion fraction in the matrix and the calculated rim thickness. Then the rim bubble pressure is obtained as a function of fuel burnup and bubble size from the proportionality constant. Therefore, the present model can provide some useful information that would be required to analyze the behavior of high burnup PWR UO{sub 2} fuel under both normal and transient operating conditions. 28 refs., 9 figs. (Author)

  16. Tritium contamination and decontamination of sealing oil for vacuum pump

    Energy Technology Data Exchange (ETDEWEB)

    Takeishi, T.; Kotoh, K.; Kawabata, Y.; Tanaka, J.I. [Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Kawamura, S.; Iwata, M. [ATOX Co. Ltd, Technoly Development Center, Kashiwa, Chiba (Japan)

    2015-03-15

    The existence of tritium-contaminated oils from vacuum pumps used in tritium facilities, is becoming an important issue since there is no disposal way for tritiated waste oils. On recovery of tritiated water vapor in gas streams, it is well-known that the isotope exchange reaction between the gas phase and the liquid phase occurs effectively at room temperature. We have carried out experiments using bubbles to examine the tritium contamination and decontamination of a volume of rotary-vacuum-pump oil. The contamination of the pump oil was made by bubbling tritiated water vapor and tritiated hydrogen gas into the oil. Subsequently the decontamination was processed by bubbling pure water vapor and dry argon gas into the tritiated oil. Results show that the water vapor bubbling was more effective than dry argon gas. The experiment also shows that the water vapor bubbling in an oil bottle can remove and transfer tritium efficiently from the tritiated oil into another water-bubbling bottle.

  17. LOX/LH2 vane pump for auxiliary propulsion systems

    Science.gov (United States)

    Hemminger, J. A.; Ulbricht, T. E.

    1985-01-01

    Positive displacement pumps offer potential efficiency advantages over centrifugal pumps for future low thrust space missions. Low flow rate applications, such as space station auxiliary propulsion or dedicated low thrust orbiter transfer vehicles, are typical of missions where low flow and high head rise challenge centrifugal pumps. The positive displacement vane pump for pumping of LOX and LH2 is investigated. This effort has included: (1) a testing program in which pump performance was investigated for differing pump clearances and for differing pump materials while pumping LN2, LOX, and LH2; and (2) an analysis effort, in which a comprehensive pump performance analysis computer code was developed and exercised. An overview of the theoretical framework of the performance analysis computer code is presented, along with a summary of analysis results. Experimental results are presented for pump operating in liquid nitrogen. Included are data on the effects on pump performance of pump clearance, speed, and pressure rise. Pump suction performance is also presented.

  18. Bubble Size Distribution in a Vibrating Bubble Column

    Science.gov (United States)

    Mohagheghian, Shahrouz; Wilson, Trevor; Valenzuela, Bret; Hinds, Tyler; Moseni, Kevin; Elbing, Brian

    2016-11-01

    While vibrating bubble columns have increased the mass transfer between phases, a universal scaling law remains elusive. Attempts to predict mass transfer rates in large industrial scale applications by extrapolating laboratory scale models have failed. In a stationary bubble column, mass transfer is a function of phase interfacial area (PIA), while PIA is determined based on the bubble size distribution (BSD). On the other hand, BSD is influenced by the injection characteristics and liquid phase dynamics and properties. Vibration modifies the BSD by impacting the gas and gas-liquid dynamics. This work uses a vibrating cylindrical bubble column to investigate the effect of gas injection and vibration characteristics on the BSD. The bubble column has a 10 cm diameter and was filled with water to a depth of 90 cm above the tip of the orifice tube injector. BSD was measured using high-speed imaging to determine the projected area of individual bubbles, which the nominal bubble diameter was then calculated assuming spherical bubbles. The BSD dependence on the distance from the injector, injector design (1.6 and 0.8 mm ID), air flow rates (0.5 to 5 lit/min), and vibration conditions (stationary and vibration conditions varying amplitude and frequency) will be presented. In addition to mean data, higher order statistics will also be provided.

  19. Dynamic Bubble Behaviour during Microscale Subcooled Boiling

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; PENG Xiao-Feng; David M.Christopher

    2005-01-01

    @@ Bubble cycles, including initiation, growth and departure, are the physical basis of nucleate boiling. The presentinvestigation, however, reveals unusual bubble motions during subcooled nucleate boiling on microwires 25 orl00μm in diameter. Two types of bubble motions, bubble sweeping and bubble return, are observed in theexperiments. Bubble sweeping describes a bubble moving back and forth along the wire, which is motion parallelto the wire. Bubble return is the bubble moving back to the wire after it has detached or leaping above thewire. Theoretical analyses and numerical simulations are conducted to investigate the driving mechanisms forboth bubble sweeping and return. Marangoni flow from warm to cool regions along the bubble interface is foundto produce the shear stresses needed to drive these unusual bubble movements.

  20. 径向柱塞式变量液压泵的结构及工作原理%Structure and Operating Principle of Radial Piston Variable Hydraulic Pump

    Institute of Scientific and Technical Information of China (English)

    王霜; 王明章

    2014-01-01

    采用径向柱塞式变量液压泵作为主泵的闭心恒压式液压系统,其最大优点是能根据实际作业需要自动改变流量输出。就径向柱塞式变量液压泵的基本结构和工作原理进行了详细分析,以供实际使用中参考。%Using radial piston variable hydraulic pump as closed center constant hydraulic system of the main pump,its biggest advantage was based on the actual needs of the job,it could automatically change the flow output. The radial piston pump variable basic structure and operating principle was conducted,so as to provide the reference for actual use.

  1. Optimal Design and Operation for a No-Moving-Parts-Valve (NMPV Micro-Pump with a Diffuser Width of 500 µm

    Directory of Open Access Journals (Sweden)

    Jia-Ming Sun

    2009-05-01

    Full Text Available A no-moving-parts-valve (NMPV with a diffuser width of D = 500 microns was investigated in this study by numerical simulations at Reynolds numbers, ReD, ranging from 20 to 75, and expansion valve angles ranging from 30° < θ1 < 57° and 110° < θ2 < 120°. The D p,i value, 1.02 < D p,i < 1.14, is larger within the proposed range of the expansion valve angles. A flow channel structure with a depth of 500 micron is manufactured using yellow light lithography in this study. From prior analyses and experiments, it is found that piezoelectric films work better at a buzz driving frequency of f < 30Hz and the best operating frequency is at a driving frequency of f = 10Hz because it produces the largest net flow. In addition, the expansion angles θ1 = 30° and θ2 = 120° are the best expansion angles because they produce the largest net flow. These related results are very helpful for the actual design of no-moving-parts-valve micro-pump.

  2. A high-field 3He Metastability Exchange Optical Pumping polarizer operating in a 1.5 T medical scanner for lung MRI

    CERN Document Server

    Collier, G; Wojna, A; Głowacz, B; Suchanek, M; Olejniczak, Z; Dohnalik, T

    2013-01-01

    After being hyperpolarized using the technique of Metastability Exchange Optical Pumping (MEOP), 3He can be used as a contrast agent for lung magnetic resonance imaging (MRI). MEOP is usually performed at low magnetic field (~ 1 mT) and low pressure (~ 1 mbar), which results in a low magnetization production rate. A delicate polarization-preserving step of compression is also required. It was demonstrated in sealed cells that high nuclear polarization values can be obtained at higher pressures with MEOP, if performed at high magnetic field (non-standard conditions). In this work the feasibility of building a high-field polarizer that operates within a commercial 1.5 T scanner was evaluated. Preliminary measurements of nuclear polarization with sealed cells filled at different 3He gas pressures (1.33 to 267 mbar) were performed. The use of an annular shape for the laser beam increased by 25 % the achievable nuclear polarization equilibrium value (Meq) at 32 and 67 mbar as compared to a Gaussian beam shape. Meq...

  3. Designing and operating optimization of ground-source heat pump system in severe cold area%严寒地区地埋管地源热泵系统设计及运行优化

    Institute of Scientific and Technical Information of China (English)

    刘逸; 李炳熙; 付忠斌; 方明洙

    2011-01-01

    Makes a heating condition optimizing experiment for a ground-source heat pump system, and the results show that heat pump and underground heat-exchanger reach steady-state after 6 hours and heat absorption of underground heat-exchanger per meter depth is 24. 5 W/m under the continuous operation condition! The ground temperature can restore in time! The OOP of the system is increased by 4.34% and the COP of the heat pump is increased by 3.23%; the COP of the system and heat pump are highest when two compressors operating, respectively are 12.2% and 11% higher than that of four compressors; the COP of the system is increased by 12.5% when two compressors operate and the circulating pumps adopt the inverter control and the COP of the heat pump is increased by 6.42% when three compressors operate and the circulating pumps adopt the inverter control under intermittent operation condition.%对某地埋管地源热泵系统冬季供热工况进行了优化实验.结果表明,系统连续运行时,6h后机组和地埋管换热器达到稳定状态,地埋管换热器单位埋深的取热量为24.5W/m;系统间歇运行时,土壤温度能及时恢复,系统的COP提高4.34%,机组的COP提高3.23%,2台压缩机工作时系统和机组的COP值最大,比4台压缩机工作时分别高12.2%和11%,2台压缩机运行、循环泵采用变频控制时,系统COP提高了12.5%;3台压缩机运行、循环泵采用变频控制时,系统COP提高了6.42%.

  4. How to Ensure Long -term Stable Operation of Ground Source Heat Pump System for Heating Biogas Digester%如何保证地源热泵式沼气池加温系统长期稳定运行

    Institute of Scientific and Technical Information of China (English)

    张迪; 石惠娴; 朱洪光; 雷勇; 王卓

    2011-01-01

    针对地源热泵式沼气池加温系统中出现的冬夏季取排热不平衡从而影响其长期稳定运行的问题,本文在采取控制运行方式、增加辅助热源和蓄热系统解决方法的分析基础上,从充分利用可再生能源和地源热泵设备的角度出发,提出热泵供热和制冷互补模式与太阳能-地源热泵多功能互补模式,并对其可行性进行分析.%To address the problem of heat imbalance of soil between winter and summer led by ground source heat pump system for heating biogas digester and to ensure the system running more stably, effectively in a long time , the paper presents the advantages and disadvantages of controlling operation model and solar assisted ground source heat pump system with heat storage.What's more, the paper also proposes complementary models of heafing and cooling of heat pump and multifunctional system integrationg solar energy with ground source heat pump, and analyses the possibility of the above two solutions from the perspective of making full use of renewable energy and the equipment of ground soure heat pump.

  5. Stable tridimensional bubble clusters in multi-bubble sonoluminescence (MBSL).

    Science.gov (United States)

    Rosselló, J M; Dellavale, D; Bonetto, F J

    2015-01-01

    In the present work, stable clusters made of multiple sonoluminescent bubbles are experimentally and theoretically studied. Argon bubbles were acoustically generated and trapped using bi-frequency driving within a cylindrical chamber filled with a sulfuric acid aqueous solution (SA85w/w). The intensity of the acoustic pressure field was strong enough to sustain, during several minutes, a large number of positionally and spatially fixed (without pseudo-orbits) sonoluminescent bubbles over an ellipsoidally-shaped tridimensional array. The dimensions of the ellipsoids were studied as a function of the amplitude of the applied low-frequency acoustic pressure (PAc(LF)) and the static pressure in the fluid (P0). In order to explain the size and shape of the bubble clusters, we performed a series of numerical simulations of the hydrodynamic forces acting over the bubbles. In both cases the observed experimental behavior was in excellent agreement with the numerical results. The simulations revealed that the positionally stable region, mainly determined by the null primary Bjerknes force (F→Bj), is defined as the outer perimeter of an axisymmetric ellipsoidal cluster centered in the acoustic field antinode. The role of the high-frequency component of the pressure field and the influence of the secondary Bjerknes force are discussed. We also investigate the effect of a change in the concentration of dissolved gas on the positional and spatial instabilities through the cluster dimensions. The experimental and numerical results presented in this paper are potentially useful for further understanding and modeling numerous current research topics regarding multi-bubble phenomena, e.g. forces acting on the bubbles in multi-frequency acoustic fields, transient acoustic cavitation, bubble interactions, structure formation processes, atomic and molecular emissions of equal bubbles and nonlinear or unsteady acoustic pressure fields in bubbly media.

  6. Proper Sizing of Circulation Pumps

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Nørgaard, Jørgen

    2007-01-01

    , but the results can be applied to Europe in general. Despite the small sample of houses involved in the test, 15 houses, some rather safe conclusions can be drawn from the results, which showed that newly developed pumps with power consumption around 5-8 W, can perform the task of circulating the water...... sufficiently to keep the houses satisfactorily warm during the heating season of the test. The old replaced pumps used 5-10 times more power. In Europe alone, a gradual replacement of the present vastly oversized pumps with such small but sufficient pumps can save the construction of 17 large power plants...... as well as their pollution during operation. Policy measures are proposed of how to ensure that in the future only such energy saving pumps are installed. Furthermore, on the basis of the historic experiences with circulation pumps some con¬clusions are drawn on how to investigate, develop and market new...

  7. Penis Pump

    Science.gov (United States)

    ... claim that they can be used to increase penis size, but there's no evidence that they work for ... circumstances, using a penis pump might help your penis maintain its natural size and shape after prostate surgery or if you ...

  8. Rapid-Cycling Bubble-Chamber, details

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    Parts of the hydraulic expansion system of the Rapid-Cycling Bubble-Chamber (RCBC). RCBC was the largest of 3 rapid-cycling bubble-chambers (the others were LEBC and HOLEBC), used as target- and vertex-detectors within the European Hybrid Spectrometer (EHS) in the SPS North Area (EHN1). RCBC contained 250 l of liquid hydrogen and was located inside a 3 T superconducting magnet. It was designed for 30 expansions/s (100 times faster than BEBC), the system shown here allowed 50 expansions/s. RCBC operated from 1981 to 1983 for experiments NA21, NA22 and NA23 at a rate of 15 expansions/s, clocking up a total of over 4 million. In the rear, at left, is bearded Lucien Veillet; Augustin Didona is at the right. See also 8001009. The installation of the piston assembly in the RCBC chamber body is shown in the Annual Report 1980, p.65.

  9. Hydrodynamic models for slurry bubble column reactors

    Energy Technology Data Exchange (ETDEWEB)

    Gidaspow, D. [IIT Center, Chicago, IL (United States)

    1995-12-31

    The objective of this investigation is to convert a {open_quotes}learning gas-solid-liquid{close_quotes} fluidization model into a predictive design model. This model is capable of predicting local gas, liquid and solids hold-ups and the basic flow regimes: the uniform bubbling, the industrially practical churn-turbulent (bubble coalescence) and the slugging regimes. Current reactor models incorrectly assume that the gas and the particle hold-ups (volume fractions) are uniform in the reactor. They must be given in terms of empirical correlations determined under conditions that radically differ from reactor operation. In the proposed hydrodynamic approach these hold-ups are computed from separate phase momentum balances. Furthermore, the kinetic theory approach computes the high slurry viscosities from collisions of the catalyst particles. Thus particle rheology is not an input into the model.

  10. Bubbling behaviors induced by gas-liquid mixture permeating through a porous medium

    Science.gov (United States)

    Hu, Liang; Li, Mingbo; Chen, Wenyu; Xie, Haibo; Fu, Xin

    2016-08-01

    This paper investigates the bubbling behaviors induced by gas-liquid mixture permeating through porous medium (PM), which was observed in developing immersion lithography system and was found having great differences with traditional bubbling behaviors injected with only gas phase through the PM. An experimental setup was built up to investigate the bubbling characteristics affected by the mixed liquid phase. Both the flow regimes of gas-liquid mixture in micro-channel (upstream of the PM) and the bubbling flow regimes in water tank (downstream of the PM) were recorded synchronously by high-speed camera. The transitions between the flow regimes are governed by gas and liquid Weber numbers. Based on the image analysis, the characteristic parameters of bubbling region, including the diameter of bubbling area on PM surface, gas-phase volume flux, and dispersion angle of bubbles in suspending liquid, were studied under different proportions of gas and liquid flow rate. Corresponding empirical correlations were developed to describe and predict these parameters. Then, the pertinent bubble characteristics in different bubbling flow regimes were systematically investigated. Specifically, the bubble size distribution and the Sauter mean diameter affected by increasing liquid flow rate were studied, and the corresponding analysis was given based on the hydrodynamics of bubble-bubble and bubble-liquid interactions. According to dimensionless analysis, the general prediction equation of Sauter mean diameter under different operating conditions was proposed and confirmed by experimental data. The study of this paper is helpful to improve the collection performance of immersion lithography and aims to reveal the differences between the bubbling behaviors on PM caused by only gas flow and gas-liquid mixture flow, respectively, for the researches of fluid flow.

  11. Explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.

    2008-01-01

    Explosive evaporation occurs when a liquid is exposed to extremely high heat-fluxes. Within a few microseconds a bubble in the form vapour film is generated, followed by rapid growth due to the pressure impulse and finally the bubbles collapse. This effect, which already has proven its use in curren

  12. Bubble chamber: colour enhanced tracks

    CERN Multimedia

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  13. Bubble coalescence in breathing DNA

    DEFF Research Database (Denmark)

    Novotný, Tomas; Pedersen, Jonas Nyvold; Ambjörnsson, Tobias;

    2007-01-01

    We investigate the coalescence of two DNA bubbles initially located at weak segments and separated by a more stable barrier region in a designed construct of double-stranded DNA. The characteristic time for bubble coalescence and the corresponding distribution are derived, as well as the distribu...

  14. Triangular bubble spline surfaces.

    Science.gov (United States)

    Kapl, Mario; Byrtus, Marek; Jüttler, Bert

    2011-11-01

    We present a new method for generating a [Formula: see text]-surface from a triangular network of compatible surface strips. The compatible surface strips are given by a network of polynomial curves with an associated implicitly defined surface, which fulfill certain compatibility conditions. Our construction is based on a new concept, called bubble patches, to represent the single surface patches. The compatible surface strips provide a simple [Formula: see text]-condition between two neighboring bubble patches, which are used to construct surface patches, connected with [Formula: see text]-continuity. For [Formula: see text], we describe the obtained [Formula: see text]-condition in detail. It can be generalized to any [Formula: see text]. The construction of a single surface patch is based on Gordon-Coons interpolation for triangles.Our method is a simple local construction scheme, which works uniformly for vertices of arbitrary valency. The resulting surface is a piecewise rational surface, which interpolates the given network of polynomial curves. Several examples of [Formula: see text], [Formula: see text] and [Formula: see text]-surfaces are presented, which have been generated by using our method. The obtained surfaces are visualized with reflection lines to demonstrate the order of smoothness.

  15. Squeezing through: capsule or bubble?

    CERN Document Server

    Dawson, Geoffrey

    2013-01-01

    In this fluid dynamics video, we compare the deformation of two flexible particles as they propagate through a sudden constriction of a liquid filled channel under constant-flux flow: a gas bubble, and a capsule formed by encapsulating a liquid droplet in a cross-linked polymeric membrane. Both bubble and capsule adopt highly contorted configurations as they squeeze through the constriction, exhibit broadly similar features over a wide range of flow rates, and rupture for sufficiently high flow rates. However, at flow rates prior to rupture, certain features of the deformation allow bubble and capsule to be distinguished: bubbles exhibit a tip-streaming singularity associated with critical thinning of the rear of the bubble, while the capsule membrane wrinkles under large compressive stresses induced by the constriction.

  16. Growing bubbles rising in line

    Directory of Open Access Journals (Sweden)

    John F. Harper

    2001-01-01

    Full Text Available Over many years the author and others have given theories for bubbles rising in line in a liquid. Theory has usually suggested that the bubbles will tend towards a stable distance apart, but experiments have often showed them pairing off and sometimes coalescing. However, existing theory seems not to deal adequately with the case of bubbles growing as they rise, which they do if the liquid is boiling, or is a supersaturated solution of a gas, or simply because the pressure decreases with height. That omission is now addressed, for spherical bubbles rising at high Reynolds numbers. As the flow is then nearly irrotational, Lagrange's equations can be used with Rayleigh's dissipation function. The theory also works for bubbles shrinking as they rise because they dissolve.

  17. Sorption product heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Antonini, G.; Francois, O.; Gendarme, J.P.; Guilleminot, J.J.; Meunier, F.

    1988-07-15

    A continuous operating, and thus with enhanced performance, heat pump is presented. In this heat pump, the heat transfer between the hot source and the output system or network is realized through a solid adsorbent-refrigerant couple having endothermal desorption properties and exothermal adsorption or absorption properties. The sorption products are carried in a closed cycle movement between the two parts of the reactor. Each side of the reactor is assuming always the same function and the thermal inertia have to be overcome only when starting the reactor.

  18. Experimental Investigation of a Rectangular Airlift Pump

    Directory of Open Access Journals (Sweden)

    I. I. Esen

    2010-01-01

    Full Text Available Hydraulic performance of an airlift pump having a rectangular cross-section 20 mm × 80 mm was investigated through an experimental program. The pump was operated at six different submergence ratios and the liquid flow rate was measured at various flowrates of air injected. The effectiveness of the pump, defined as the ratio of the mass of liquid pumped to the mass of air injected, was determined as a function of the mass of air injected for different submergence ratios. Results obtained were compared with those for circular airlift pumps using an analytical model for circular pumps. Effectiveness of the rectangular airlift pump was observed to be comparable to that of the circular pumps. Hydraulic performance of the rectangular airlift pump investigated was then described by a set of semilogarithmic empirical equations.

  19. Black Hole Blows Big Bubble

    Science.gov (United States)

    2010-07-01

    astronomers understand the similarity between small black holes formed from exploded stars and the supermassive black holes at the centres of galaxies. Very powerful jets have been seen from supermassive black holes, but are thought to be less frequent in the smaller microquasar variety. The new discovery suggests that many of them may simply have gone unnoticed so far. The gas-blowing black hole is located 12 million light-years away, in the outskirts of the spiral galaxy NGC 7793 (eso0914b). From the size and expansion velocity of the bubble the astronomers have found that the jet activity must have been ongoing for at least 200 000 years. Notes [1] Astronomers do not have yet any means of measuring the size of the black hole itself. The smallest stellar black hole discovered so far has a radius of about 15 km. An average stellar black hole of about 10 solar masses has a radius of about 30 km, while a "big" stellar black hole may have a radius of up to 300 km. This is still much smaller than the jets, which extend out to several hundreds light years on each side of the black hole, or about several thousand million million km! More information This result appears in a paper published in this week's issue of the journal Nature (A 300 parsec long jet-inflated bubble around a powerful microquasar in the galaxy NGC 7793, by Manfred W. Pakull, Roberto Soria and Christian Motch). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising

  20. Distribution of Pressure Fluctuations in a Prototype Pump Turbine at Pump Mode

    OpenAIRE

    Sun, Yuekun; Zuo, Zhigang; Liu, Shuhong; Liu, Jintao; Wu, Yulin

    2014-01-01

    Pressure fluctuations are very important characteristics in pump turbine’s operation. Many researches have focused on the characteristics (amplitude and frequencies) of pressure fluctuations at specific locations, but little researches mentioned the distribution of pressure fluctuations in a pump turbine. In this paper, 3D numerical simulations using SST k-ω turbulence model were carried out to predict the pressure fluctuations distribution in a prototype pump turbine at pump mode. Three oper...

  1. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  2. Direct Measurement of the Bubble Nucleation Energy Threshold in a CF3I Bubble Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, E. [Indiana Univ. South Bend, IN (United States); Benjamin, T. [Indiana Univ. South Bend, IN (United States); Brice, S. J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Broemmelsiek, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Collar, J. I. [Univ. of Chicago, IL (United States); Cooper, P. S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Crisler, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Dahl, C. E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Northwestern Univ., Evanston, IL (United States); Fustin, D. [Univ. of Chicago, IL (United States); Hall, Jeter C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Harnish, C. [Indiana Univ. South Bend, IN (United States); Levine, I. [Indiana Univ. South Bend, IN (United States); Lippincott, W. H. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Moan, T. [Indiana Univ. South Bend, IN (United States); Nania, T. [Indiana Univ. South Bend, IN (United States); Neilson, R. [Univ. of Chicago, IL (United States); Ramberg, E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Robinson, A. E. [Univ. of Chicago, IL (United States); Ruschman, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sonnenschein, Andrew [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Vazquez-Jauregui, E. [SNOLAB, Sudbury, ON (Canada); RIvera, R. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Uplegger, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-07-30

    Here, we measured the energy threshold and efficiency for bubble nucleation from iodine recoils in a CF3I bubble chamber in the energy range of interest for a dark matter search. These interactions cannot be probed by standard neutron calibration methods, so we develop a new technique by observing the elastic scattering of 12 GeV/c negative pions. The pions are tracked with a silicon pixel telescope and the reconstructed scattering angle provides a measure of the nuclear recoil kinetic energy. The bubble chamber was operated with a nominal threshold of (13.6±0.6) keV. Interpretation of the results depends on the response to fluorine and carbon recoils, but in general we find agreement with the predictions of the classical bubble-nucleation theory. Moreover, this measurement confirms the applicability of CF3I as a target for spin-independent dark matter interactions and represents a novel technique for calibration of superheated fluid detectors.

  3. Effect of gas expansion on the front shape of a Taylor bubble: an experimental contribution

    Directory of Open Access Journals (Sweden)

    Santos Laura

    2014-03-01

    Full Text Available An experimental study where an individual Taylor bubble rises through water with different bubble volume expansion rates is presented with the (front bubble shape determination as main objective. A combination of two techniques, Particle Image Velocimetry (PIV and Pulsed Shadowgraphy (PS, was used to collect images for further treatment in order to characterize the liquid flow pattern in front of the bubble and the bubble shape. Processing the images acquired with pulsed illumination from behind the bubble it was possible to define with precision the bubble shape at different stages when it was expanding. The operation conditions used allowed a wide range of volume expansion rates (0 to 28.5 × 10-6 m3/s with a significant effect on the Taylor bubble velocity; increases in bubble velocity up to 21% were observed relatively to constant volume system condition. Nevertheless, it seems that the front shape of Taylor bubbles does not change significantly with the upward liquid flow rates induced by gas expansion, at least for the volume expansion rates used in the experiments.

  4. Electrorheological fluid-actuated microfluidic pump

    Science.gov (United States)

    Liu, Liyu; Chen, Xiaoqing; Niu, Xize; Wen, Weijia; Sheng, Ping

    2006-08-01

    The authors report the design and implementation of an electrorheological (ER) fluid-actuated microfluidic pump, with programmable digital control. Our microfluidic pump has a multilayered structure fabricated on polydimethylsiloxane by soft-lithographic technique. The ER microfluidic pump exhibits good performance at high pumping frequencies and uniform liquid flow characteristics. It can be easily integrated with other microfluidic components. The programmable control also gives the device flexibility in its operations.

  5. The Terminal Velocity of a Bubble in an Oscillating Flow

    Science.gov (United States)

    Romero, L. A.; Kraynik, A. M.; Torczynski, J. R.

    2010-11-01

    A bubble in an acoustic field experiences a net "Bjerknes" force from the nonlinear coupling of its radial oscillations with the oscillating buoyancy force. It is typically assumed that the bubble's net terminal velocity can be found by considering a spherical bubble with the imposed "Bjerknes stresses". We have analyzed the motion of such a bubble using a rigorous perturbation approach and found that one must include a term involving an effective mass flux through the bubble that arises from the time average of the second-order nonlinear terms in the kinematic boundary condition. The importance of this term is governed by the dimensionless parameter α=R^2φ / R^2φ ν . - ν, where R is the bubble radius, φ is the driving frequency, and ν is the liquid kinematic viscosity. If α is large, this term is unimportant, but if α is small, this term is the dominant factor in determining the terminal velocity. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  6. The effect of nearby bubbles on array gain.

    Science.gov (United States)

    Culver, R Lee; Park, J Daniel; Leighton, Timothy G; Coles, David G H

    2011-12-01

    The coherent processing of signals from multiple hydrophones in an array offers improvements in angular resolution and signal-to-noise ratio. When the array is steered in a particular direction, the signals arriving from that direction are added in phase, and any signals arriving from other directions are not. Array gain (AG) is a measure of how much the signal arriving from the steering direction is amplified relative to signals arriving from all other directions. The subject of this paper is the manner in which the AG of an acoustic array operating in water that contains air bubbles is affected by scattering from nearby bubbles. The effects of bubbles on acoustic attenuation and dispersion are considered separately from their effects on AG. Acoustic measurements made in bubbly water using the AB Wood tank at the Institute of Sound and Vibration Research, University of Southampton, in June 2008 show that as bubble density increases, relative phase shifts in individual hydrophone signals increase and signal correlation among the hydrophones is reduced. A theory and numerical simulation linking bubble density at the hydrophone to the AG is in good agreement with the measurements up to the point where multiple scattering becomes important.

  7. Doughnut-shaped soap bubbles

    Science.gov (United States)

    Préve, Deison; Saa, Alberto

    2015-10-01

    Soap bubbles are thin liquid films enclosing a fixed volume of air. Since the surface tension is typically assumed to be the only factor responsible for conforming the soap bubble shape, the realized bubble surfaces are always minimal area ones. Here, we consider the problem of finding the axisymmetric minimal area surface enclosing a fixed volume V and with a fixed equatorial perimeter L . It is well known that the sphere is the solution for V =L3/6 π2 , and this is indeed the case of a free soap bubble, for instance. Surprisingly, we show that for V <α L3/6 π2 , with α ≈0.21 , such a surface cannot be the usual lens-shaped surface formed by the juxtaposition of two spherical caps, but is rather a toroidal surface. Practically, a doughnut-shaped bubble is known to be ultimately unstable and, hence, it will eventually lose its axisymmetry by breaking apart in smaller bubbles. Indisputably, however, the topological transition from spherical to toroidal surfaces is mandatory here for obtaining the global solution for this axisymmetric isoperimetric problem. Our result suggests that deformed bubbles with V <α L3/6 π2 cannot be stable and should not exist in foams, for instance.

  8. Energy spectra in bubbly turbulence

    CERN Document Server

    Prakash, Vivek N; Ramos, Fabio Ernesto Mancilla; Tagawa, Yoshiyuki; Lohse, Detlef; Sun, Chao

    2013-01-01

    We conduct experiments in a turbulent bubbly flow to study the unknown nature of the transition between the classical -5/3 energy spectrum scaling for a single-phase turbulent flow and the -3 scaling for a swarm of bubbles rising in a quiescent liquid and of bubble-dominated turbulence. The bubblance parameter, b, which measures the ratio of the bubble-induced kinetic energy to the kinetic energy induced by the turbulent liquid fluctuations before bubble injection, is used to characterise the bubbly flow. We vary b from $b = \\infty$ (pseudo-turbulence) to b = 0 (single-phase flow) over 2-3 orders of magnitude: ~O(0.01, 0.1, 5) to study its effect on the turbulent energy spectrum and liquid velocity fluctuations. The experiments are conducted in a multi-phase turbulent water tunnel with air bubbles of diameters 2-4 mm and 3-5 mm. An active-grid is used to generate nearly homogeneous and isotropic turbulence in the liquid flow. The liquid speeds and gas void fractions are varied to achieve the above mentioned b...

  9. BEBC, the Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    The vessel of the Big European Bubble Chamber, BEBC, was installed at the beginning of the 1970s. The large stainless-steel vessel, measuring 3.7 metres in diameter and 4 metres in height, was filled with 35 cubic metres of liquid (hydrogen, deuterium or a neon-hydrogen mixture), whose sensitivity was regulated by means of a huge piston weighing 2 tonnes. During each expansion, the trajectories of the charged particles were marked by a trail of bubbles, where liquid reached boiling point as they passed through it. The first images were recorded in 1973 when BEBC, equipped with the largest superconducting magnet in service at the time, first received beam from the PS. In 1977, the bubble chamber was exposed to neutrino and hadron beams at higher energies of up to 450 GeV after the SPS came into operation. By the end of its active life in 1984, BEBC had delivered a total of 6.3 million photographs to 22 experiments devoted to neutrino or hadron physics. Around 600 scientists from some fifty laboratories through...

  10. The influence of polymeric membrane gas spargers on hydrodynamics and mass transfer in bubble column bioreactors

    DEFF Research Database (Denmark)

    Tirunehe, Gossay; Norddahl, B.

    2016-01-01

    Gas sparging performances of a flat sheet and tubular polymeric membranes were investigated in 3.1 m bubble column bioreactor operated in a semi batch mode. Air–water and air–CMC (Carboxymethyl cellulose) solutions of 0.5, 0.75 and 1.0 % w/w were used as interacting gas–liquid mediums. CMC...... solutions were employed in the study to simulate rheological properties of bioreactor broth. Gas holdup, bubble size distribution, interfacial area and gas–liquid mass transfer were studied in the homogeneous bubbly flow hydrodynamic regime with superficial gas velocity (UG) range of 0.0004–0.0025 m....../s. The study indicated that the tubular membrane sparger produced the highest gas holdup and densely populated fine bubbles with narrow size distribution. An increase in liquid viscosity promoted a shift in bubble size distribution to large stable bubbles and smaller specific interfacial area. The tubular...

  11. 寒冷地区某办公楼地源热泵空调系统运行分析%Operational analysis of ground-source heat pump air conditioning system for an office building in cold zone

    Institute of Scientific and Technical Information of China (English)

    郑晓娜

    2015-01-01

    Combined with the project,presents the test results of ground-source heat pump under the shallow geothermal condition.The soil thermal balance analysis results show that the soil temperature increases by 0.3 ℃ after a period of cooling and heating season on condition that heat released from ground-source heat pump units to soil is 1.425 TJ.The analysis of operational data shows that temperature differences of entering and leaving water of condensers or evaporators on operation condition are commonly smaller than those on design condition for ground-source heat pump units,resulting in higher energy consumption of pumps.Suggests to apply the control mode of constant temperature difference and variable frequency of pump.%结合寒冷地区某办公楼地源热泵项目,介绍了浅层地热地质条件的测试结果。土壤热平衡分析结果表明,如果地源热泵机组全年向岩土体排热量为1.425 TJ,经过一个制冷季和一个供暖季后,岩土体温度升高幅度为0.30℃。运行数据分析结果表明,地源热泵冷凝器与蒸发器进出口温差在运行过程中通常小于设计温差,造成水泵能耗偏高,建议采用定温差、水泵变频调节的控制方式。

  12. Partial coalescence of soap bubbles

    Science.gov (United States)

    Harris, Daniel M.; Pucci, Giuseppe; Bush, John W. M.

    2015-11-01

    We present the results of an experimental investigation of the merger of a soap bubble with a planar soap film. When gently deposited onto a horizontal film, a bubble may interact with the underlying film in such a way as to decrease in size, leaving behind a smaller daughter bubble with approximately half the radius of its progenitor. The process repeats up to three times, with each partial coalescence event occurring over a time scale comparable to the inertial-capillary time. Our results are compared to the recent numerical simulations of Martin and Blanchette and to the coalescence cascade of droplets on a fluid bath.

  13. Sonochemistry and the acoustic bubble

    CERN Document Server

    Grieser, Franz; Enomoto, Naoya; Harada, Hisashi; Okitsu, Kenji; Yasui, Kyuichi

    2015-01-01

    Sonochemistry and the Acoustic Bubble provides an introduction to the way ultrasound acts on bubbles in a liquid to cause bubbles to collapse violently, leading to localized 'hot spots' in the liquid with temperatures of 5000° celcius and under pressures of several hundred atmospheres. These extreme conditions produce events such as the emission of light, sonoluminescence, with a lifetime of less than a nanosecond, and free radicals that can initiate a host of varied chemical reactions (sonochemistry) in the liquid, all at room temperature. The physics and chemistry behind the p

  14. Bubble Growth in Lunar Basalts

    Science.gov (United States)

    Zhang, Y.

    2009-05-01

    Although Moon is usually said to be volatile-"free", lunar basalts are often vesicular with mm-size bubbles. The vesicular nature of the lunar basalts suggests that they contained some initial gas concentration. A recent publication estimated volatile concentrations in lunar basalts (Saal et al. 2008). This report investigates bubble growth on Moon and compares with that on Earth. Under conditions relevant to lunar basalts, bubble growth in a finite melt shell (i.e., growth of multiple regularly-spaced bubbles) is calculated following Proussevitch and Sahagian (1998) and Liu and Zhang (2000). Initial H2O content of 700 ppm (Saal et al. 2008) or lower is used and the effect of other volatiles (such as carbon dioxide, halogens, and sulfur) is ignored. H2O solubility at low pressures (Liu et al. 2005), concentration-dependent diffusivity in basalt (Zhang and Stolper 1991), and lunar basalt viscosity (Murase and McBirney 1970) are used. Because lunar atmospheric pressure is essentially zero, the confining pressure on bubbles is completely supplied by the overlying magma. Due to low H2O content in lunar basaltic melt (700 ppm H2O corresponds to a saturation pressure of 75 kPa), H2O bubbles only grow in the upper 16 m of a basalt flow or lake. A depth of 20 mm corresponds to a confining pressure of 100 Pa. Hence, vesicular lunar rocks come from very shallow depth. Some findings from the modeling are as follows. (a) Due to low confining pressure as well as low viscosity, even though volatile concentration is very low, bubble growth rate is extremely high, much higher than typical bubble growth rates in terrestrial melts. Hence, mm-size bubbles in lunar basalts are not strange. (b) Because the pertinent pressures are so low, bubble pressure due to surface tension plays a main role in lunar bubble growth, contrary to terrestrial cases. (c) Time scale to reach equilibrium bubble size increases as the confining pressure increases. References: (1) Liu Y, Zhang YX (2000) Earth

  15. Thermal Phase in Bubbling Geometries

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-Yong

    2008-01-01

    We use matrix model to study thermal phase in bubbling half-BPS type IIB geometries with SO(4)×SO(4) symmetry.Near the horizon limit,we find that thermal vacua of bubbling geometries have disjoint parts,and each part is one kind of phase of the thermal system.We connect the thermal dynamics of bubbling geometries with one-dimensional fermions thermal system.Finally,we try to give a new possible way to resolve information loss puzzle.

  16. Bubble Formation in Basalt-like Melts

    DEFF Research Database (Denmark)

    Jensen, Martin; Keding, Ralf; Yue, Yuanzheng

    2011-01-01

    spectroscopy analysis of gases liberated during heating of the glass reveals that small bubbles contain predominantly CH4, CO and CO2, whereas large bubbles bear N2, SO2 and H2S. The methodology utilised in this work can, besides mapping the bubbles in a glass, be applied to shed light on the sources of bubble...

  17. Bubble stimulation efficiency of dinoflagellate bioluminescence.

    Science.gov (United States)

    Deane, Grant B; Stokes, M Dale; Latz, Michael I

    2016-02-01

    Dinoflagellate bioluminescence, a common source of bioluminescence in coastal waters, is stimulated by flow agitation. Although bubbles are anecdotally known to be stimulatory, the process has never been experimentally investigated. This study quantified the flash response of the bioluminescent dinoflagellate Lingulodinium polyedrum to stimulation by bubbles rising through still seawater. Cells were stimulated by isolated bubbles of 0.3-3 mm radii rising at their terminal velocity, and also by bubble clouds containing bubbles of 0.06-10 mm radii for different air flow rates. Stimulation efficiency, the proportion of cells producing a flash within the volume of water swept out by a rising bubble, decreased with decreasing bubble radius for radii less than approximately 1 mm. Bubbles smaller than a critical radius in the range 0.275-0.325 mm did not stimulate a flash response. The fraction of cells stimulated by bubble clouds was proportional to the volume of air in the bubble cloud, with lower stimulation levels observed for clouds with smaller bubbles. An empirical model for bubble cloud stimulation based on the isolated bubble observations successfully reproduced the observed stimulation by bubble clouds for low air flow rates. High air flow rates stimulated more light emission than expected, presumably because of additional fluid shear stress associated with collective buoyancy effects generated by the high air fraction bubble cloud. These results are relevant to bioluminescence stimulation by bubbles in two-phase flows, such as in ship wakes, breaking waves, and sparged bioreactors.

  18. 2-D steering and propelling of acoustic bubble-powered microswimmers.

    Science.gov (United States)

    Feng, Jian; Yuan, Junqi; Cho, Sung Kwon

    2016-06-21

    This paper describes bi-directional (linear and rotational) propelling and 2-D steering of acoustic bubble-powered microswimmers that are achieved in a centimeter-scale pool (beyond chip level scale). The core structure of a microswimmer is a microtube with one end open in which a gaseous bubble is trapped. The swimmer is propelled by microstreaming flows that are generated when the trapped bubble is oscillated by an external acoustic wave. The bubble oscillation and thus propelling force are highly dependent on the frequency of the acoustic wave and the bubble length. This dependence is experimentally studied by measuring the resonance behaviors of the testing pool and bubble using a laser Doppler vibrometer (LDV) and by evaluating the generated streaming flows. The key idea in the present 2-D steering is to utilize this dependence. Multiple bubbles with different lengths are mounted on a single microswimmer with a variety of arrangements. By controlling the frequency of the acoustic wave, only frequency-matched bubbles can strongly oscillate and generate strong propulsion. By arranging multiple bubbles of different lengths in parallel but with their openings opposite and switching the frequency of the acoustic wave, bi-directionally linear propelling motions are successfully achieved. The propelling forces are calculated by a CFD analysis using the Ansys Fluent® package. For bi-directional rotations, a similar method but with diagonal arrangement of bubbles on a rectangular swimmer is also applied. The rotation can be easily reversed when the frequency of the acoustic wave is switched. For 2-D steering, short bubbles are aligned perpendicular to long bubbles. It is successfully demonstrated that the microswimmer navigates through a T-junction channel under full control with and without carrying a payload. During the navigation, the frequency is the main control input to select and resonate targeted bubbles. All of these operations are achieved by a single

  19. Precipitation of CuS and ZnS in a bubble column reactor

    NARCIS (Netherlands)

    Al-Tarazi, M.; Heesink, A. Bert M.; Versteeg, G. F.; Azzam, M. O. J.; Azzam, K.

    2005-01-01

    This work presents an experimental study into the precipitation of CuS and ZnS in a semibatch-wise operated bubble column. First the applied bubble column was characterized with respect to mass transfer phenomena. The influences of ionic strength and superficial gas velocity on volumetric mass trans

  20. Effect of cavity pressure on the performance of the explosive micro-bubble actuator

    NARCIS (Netherlands)

    van den Broek, D.M.; Elwenspoek, Michael Curt

    The explosive micro-bubble actuator is a new type of actuator based on bubble generation by explosive evaporation. It can operate at frequencies up to 5 kHz which is extremely high for a thermo-pneumatic actuator. At these frequencies, the device can still produce a pressure of several bars

  1. Bubble Dynamics and Resulting Noise from Traveling Bubble Cavitation.

    Science.gov (United States)

    1982-04-13

    has resulted in models which aqree well with bubble dynamics recorded by high speed film . Chahine, et. al. (23) incorporated asymmetric bubble...recording on the tape soundtrack . 3.8 Measurement of Gas Nuclei in Water The role of nuclei density and size in cavitation inception has been the subject...interference between the coherent background and the particle-diffracted radiation exooses photographic film in the far-field of the nuclei. This

  2. Analysis of Operating Characteristics of Hybrid Ground Source Heat Pump Assisted with Chiller%冷机辅助复合式地源热泵运行特性探析

    Institute of Scientific and Technical Information of China (English)

    周世玉; 崔文智

    2015-01-01

    Hybrid ground source heat pump system assisted with chiller is proposed in this paper, and also two kinds of operation scheme. System operation of 30 years is simulated using TRNSYS software. Compared with conventional ground source heat pump system, operating characteristics and the feasibility of the hybrid ground source heat pump system are analyzed from the ground temperature increase, system performance, energy consumption and also the technical and economic aspects.%提出了冷水机组和热泵机组分设的复合式地源热泵系统,并提出了两种运行方案。采用 TRNSYS软件模拟其30年的系统运行,并分别从地温增幅、系统性能、能耗及技术经济角度和常规地源热泵系统进行比较,分析了该复合式地源热泵系统的运行特性及其可行性。

  3. Pumps in wearable ultrafiltration devices: pumps in wuf devices.

    Science.gov (United States)

    Armignacco, Paolo; Garzotto, Francesco; Bellini, Corrado; Neri, Mauro; Lorenzin, Anna; Sartori, Marco; Ronco, Claudio

    2015-01-01

    The wearable artificial kidney (WAK) is a device that is supposed to operate like a real kidney, which permits prolonged, frequent, and continuous dialysis treatments for patients with end-stage renal disease (ESRD). Its functioning is mainly related to its pumping system, as well as to its dialysate-generating and alarm/shutoff ones. A pump is defined as a device that moves fluids by mechanical action. In such a context, blood pumps pull blood from the access side of the dialysis catheter and return the blood at the same rate of flow. The main aim of this paper is to review the current literature on blood pumps, describing the way they have been functioning thus far and how they are being engineered, giving details about the most important parameters that define their quality, thus allowing the production of a radar comparative graph, and listing ideal pumps' features.

  4. Engine lubrication circuit including two pumps

    Science.gov (United States)

    Lane, William H.

    2006-10-03

    A lubrication pump coupled to the engine is sized such that the it can supply the engine with a predetermined flow volume as soon as the engine reaches a peak torque engine speed. In engines that operate predominately at speeds above the peak torque engine speed, the lubrication pump is often producing lubrication fluid in excess of the predetermined flow volume that is bypassed back to a lubrication fluid source. This arguably results in wasted power. In order to more efficiently lubricate an engine, a lubrication circuit includes a lubrication pump and a variable delivery pump. The lubrication pump is operably coupled to the engine, and the variable delivery pump is in communication with a pump output controller that is operable to vary a lubrication fluid output from the variable delivery pump as a function of at least one of engine speed and lubrication flow volume or system pressure. Thus, the lubrication pump can be sized to produce the predetermined flow volume at a speed range at which the engine predominately operates while the variable delivery pump can supplement lubrication fluid delivery from the lubrication pump at engine speeds below the predominant engine speed range.

  5. 汽泵乏汽供热改造对机组安全运行的影响%Analysis on the Influence of Waste-heat-absorbing Feed Pump Turbine Transformation on Safe Operation of Unit

    Institute of Scientific and Technical Information of China (English)

    王强; 白志刚; 梁健康

    2014-01-01

    介绍了某电厂的汽动给水泵乏汽吸收式热泵机组系统,对该厂的给水泵汽轮机乏汽至主机凝汽器蝶阀进行流量计算,分析蝶阀特性,利用汽动给水泵排汽中间容积特性分析得出热泵机组故障后蝶阀动作时间与汽动给水泵排汽压力的关系,并制定合理的控制逻辑为机组的安全运行提供指导。%Waste-heat-absorbing heat pump unit of steam feed pump in a power plant was introduced. The exhausted steam flow rate between feed water pump turbine and butterfly valve of condenser was calculated. Based on the analysis of butterfly valve feature and steam volume feature,the relationship between the action time of butterfly valve and the discharge pressure of water feed pump was concluded. Besides,reasonable control logic was formulated to provide guidance for safe operation of unit.

  6. Comparison between design and actual energy performance of a HVAC-ground coupled heat pump system in cooling and heating operation

    Energy Technology Data Exchange (ETDEWEB)

    Magraner, T.; Quilis, S. [Energesis Ingenieria S.L., Ciudad Politecnica de la Innovacion, Camino de Vera s/n, 46022 Valencia (Spain); Montero, A. [Instituto de Ingenieria Energetica, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Urchueguia, J.F. [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2010-09-15

    This work compares the experimental results obtained for the energy performance study of a ground coupled heat pump system with the design values predicted by means of standard methodology. The system energy performance of a monitored ground coupled heat pump system is calculated using the instantaneous measurements of temperature, flow and power consumption and these values are compared with the numerical predictions. These predictions are performed with the TRNSYS software tool following standard procedures taking the experimental thermal loads as input values. The main result of this work is that simulation results solely based on nominal heat pump capacities and performances overestimate the measured overall energy performance by a percentage between 15% and 20%. A sensitivity analysis of the simulation results to changes in percentage of its input parameters showed that the heat pump nominal coefficient of performance is the parameter that mostly affects the energy performance predictions. This analysis supports the idea that the discrepancies between experimental results and simulation outputs for this ground coupled system are mainly due to heat pump performance degradation for being used at partial load. An estimation of the impact of this effect in energy performance predictions reduces the discrepancies to values around 5%. (author)

  7. The Housing Bubble Fact Sheet

    OpenAIRE

    Dean Baker

    2005-01-01

    This paper explains the basic facts about the current housing market. It lays out the evidence that the rise in housing prices constitutes a housing bubble - and explains what can be expected when it inevitably collapses.

  8. Bubble bean bags in shampoo

    CERN Document Server

    Kundu, Anup; Das, Gargi; Harikrishnan, G

    2011-01-01

    In these fluid dynamics videos, we, for the first time, show various interactions of a 'Taylor bubble' with their smaller and differently, shaped counterparts, in a shear thinning, non-Newtonian fluid, confined in a narrow channel.

  9. Pumps; Pumpen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, H. [Gesellschaft fuer Praktische Energiekunde e.V., Muenchen (Germany). Forschungsstelle fuer Energiewirtschaft; Hellriegel, E. [Gesellschaft fuer Praktische Energiekunde e.V., Muenchen (Germany). Forschungsstelle fuer Energiewirtschaft; Pfitzner, G. [Gesellschaft fuer Praktische Energiekunde e.V., Muenchen (Germany). Forschungsstelle fuer Energiewirtschaft

    1994-11-01

    The technical features of commercial pump types are described with regard to their technical, energy-related and economic parameters, and characteristic data are presented in the form of data sheets. This is to provide a basis for a comparative assessment of different technologies and technical variants. The chapter `System specifications` describes the various fields of application of pumps and the resulting specific requirements. The design and function of the different pump types are described in `Technical description`. `System and plant description dscribes the design and adaptation of pumps, i.e. the adaptation of the plant data to the system requirements. `Data compilation` provides a survey of the types and systematics of the compiled data as well as a decision aid for selecting the pumps best suited to the various applications. The `Data sheet` section describes the structure and handling of the data sheets as well as the data contained therein. The data sheets are contained in the apapendix of this report. The section `General analysis` compares typical technical, energy-related and economic characteristics of the different pump types. This is to enable a rough comparison of pump types and to facilitate decisions. The chapter `Example` illustrates the use of the data sheets by means of a selected example. (orig./GL) [Deutsch] Die vorliegende Arbeit hat zum Ziel, Technik seriengefertigter und marktgaengiger Pumpen in typisierter Form hinsichtlich ihrer technischen, energetischen und wirtschaftlichen Parameter zu beschreiben und ihre charakteristischen Kennwerte in Datenblaettern abzubilden. Damit wird ein grundlegendes Instrument fuer die vergleichende Beurteilung unterschiedlicher Techniken bzw. Technikvarianten hinsichtlich energetischer und wirtschaftlicher Kriterien geschaffen. Im Abschnitt `Systemanforderungen` erfolgt die Beschreibung der einzelnen Anwendungsbereiche fuer Pumpen mit den speziellen daraus resultierenden Anforderungen. Der Aufbau und

  10. Mechanisms of single bubble cleaning.

    Science.gov (United States)

    Reuter, Fabian; Mettin, Robert

    2016-03-01

    The dynamics of collapsing bubbles close to a flat solid is investigated with respect to its potential for removal of surface attached particles. Individual bubbles are created by nanosecond Nd:YAG laser pulses focused into water close to glass plates contaminated with melamine resin micro-particles. The bubble dynamics is analysed by means of synchronous high-speed recordings. Due to the close solid boundary, the bubble collapses with the well-known liquid jet phenomenon. Subsequent microscopic inspection of the substrates reveals circular areas clean of particles after a single bubble generation and collapse event. The detailed bubble dynamics, as well as the cleaned area size, is characterised by the non-dimensional bubble stand-off γ=d/Rmax, with d: laser focus distance to the solid boundary, and Rmax: maximum bubble radius before collapse. We observe a maximum of clean area at γ≈0.7, a roughly linear decay of the cleaned circle radius for increasing γ, and no cleaning for γ>3.5. As the main mechanism for particle removal, rapid flows at the boundary are identified. Three different cleaning regimes are discussed in relation to γ: (I) For large stand-off, 1.8substrate and remove particles without significant contact of the gas phase. (II) For small distances, γsubstrate are driven by the jet impact with its subsequent radial spreading, and by the liquid following the motion of the collapsing and rebounding bubble wall. Both flows remove particles. Their relative timing, which depends sensitively on the exact γ, appears to determine the extension of the area with forces large enough to cause particle detachment. (III) At intermediate stand-off, 1.1substrate, but acts with cleaning mechanisms similar to an effective small γ collapse: particles are removed by the jet flow and the flow induced by the bubble wall oscillation. Furthermore, the observations reveal that the extent of direct bubble gas phase contact to the solid is partially smaller than the

  11. The clinical monitoring and nursing of micro-pump potassium after surgery operation%外科术后微量泵经静脉补钾的临床监测及护理

    Institute of Scientific and Technical Information of China (English)

    李娟; 李勇兰; 党翠云; 曾小平

    2008-01-01

    To summarize the experience of clinical monitoring and nursing in patients who used the micro-pump potassium to rectify the hypokalemia after operation in ICU,heart surgery and common surgery department of our hospital.76 cases of hypokalemia were selected and used micro-pump to rectify the hypokalemia after surgery operation by intravenous infusion 10% liquids with original potassium chloride,the process was monitored and nursed closely.This prevented the occurrence of hypokalemia after operation effectively.During pumping potassium period,there was no phlebitis,no arrhythmia or other adverse effect occurred.Using micro-pump to supply potassium by vein to correct hypokalemia under tight clinical monitoring and nursing is effective and safe.%总结我院ICU、心脏外科、普外科病人术后使用微量泵泵钾纠正低钾血症的临床监测及护理体会.76例外科术后低钾血症患者使用微量注射泵经静脉输注浓度为10%氯化钾原液,以纠正低钾血症,补钾过程中进行严密监测和护理.有效预防了术后低血钾的发生.患者在泵钾期间无1例高钾血症发生,无静脉炎、心律失常等不良反应发生.严密的临床监测和护理下使用微量泵经静脉补钾纠正低钾血症的方法 是有效、安全的.

  12. Study and development of an air conditioning system operating on a magnetic heat pump cycle (design and testing of flow directors)

    Science.gov (United States)

    Wang, Pao-Lien

    1992-01-01

    This report describes the fabrication, design of flow director, fluid flow direction analysis and testing of flow director of a magnetic heat pump. The objectives of the project are: (1) to fabricate a demonstration magnetic heat pump prototype with flow directors installed; and (2) analysis and testing of flow director and to make sure working fluid loops flow through correct directions with minor mixing. The prototype was fabricated and tested at the Development Testing Laboratory of Kennedy Space Center. The magnetic heat pump uses rear earth metal plates rotate in and out of a magnetic field in a clear plastic housing with water flowing through the rotor plates to provide temperature lift. Obtaining the proper water flow direction has been a problem. Flow directors were installed as flow barriers between separating point of two parallel loops. Function of flow directors were proven to be excellent both analytically and experimentally.

  13. Doughnut-shaped soap bubbles

    CERN Document Server

    Preve, Deison

    2015-01-01

    Soap bubbles are thin liquid films enclosing a fixed volume of air. Since the surface tension is typically assumed to be the only responsible for conforming the soap bubble shape, the realized bubble surfaces are always minimal area ones. Here, we consider the problem of finding the axisymmetric minimal area surface enclosing a fixed volume $V$ and with a fixed equatorial perimeter $L$. It is well known that the sphere is the solution for $V=L^3/6\\pi^2$, and this is indeed the case of a free soap bubble, for instance. Surprisingly, we show that for $V<\\alpha L^3/6\\pi^2$, with $\\alpha\\approx 0.21$, such a surface cannot be the usual lens-shaped surface formed by the juxtaposition of two spherical caps, but rather a toroidal surface. Practically, a doughnut-shaped bubble is known to be ultimately unstable and, hence, it will eventually lose its axisymmetry by breaking apart in smaller bubbles. Indisputably, however, the topological transition from spherical to toroidal surfaces is mandatory here for obtainin...

  14. Temperature measurements in cavitation bubbles

    Science.gov (United States)

    Coutier-Delgosha, Olivier

    2016-11-01

    Cavitation is usually a nearly isothermal process in the liquid phase, but in some specific flow conditions like hot water or cryogenic fluids, significant temperature variations are detected. In addition, a large temperature increase happens inside the cavitation bubbles at the very end of their collapse, due to the fast compression of the gas at the bubble core, which is almost adiabatic. This process is of primary interest in various biomedical and pharmaceutical applications, where the mechanisms of bubble collapse plays a major role. To investigate the amplitude and the spatial distribution of these temperature variations inside and outside the cavitation bubbles, a system based on cold wires has been developed. They have been tested in a configuration of a single bubble obtained by submitting a small air bubble to a large amplitude pressure wave. Some promising results have been obtained after the initial validation tests. This work is funded by the Office of Naval Research Global under Grant N62909-16-1-2116, Dr. Salahuddin Ahmed & Ki-Han Kim program managers.

  15. Types of Breast Pumps

    Science.gov (United States)

    ... Devices Consumer Products Breast Pumps Types of Breast Pumps Share Tweet Linkedin Pin it More sharing options ... used for feeding a baby. Types of Breast Pumps There are three basic types of breast pumps: ...

  16. Human Aorta Is a Passive Pump

    Science.gov (United States)

    Pahlevan, Niema; Gharib, Morteza

    2012-11-01

    Impedance pump is a simple valveless pumping mechanism that operates based on the principles of wave propagation and reflection. It has been shown in a zebrafish that a similar mechanism is responsible for the pumping action in the embryonic heart during early stages before valve formation. Recent studies suggest that the cardiovascular system is designed to take advantage of wave propagation and reflection phenomena in the arterial network. Our aim in this study was to examine if the human aorta is a passive pump working like an impedance pump. A hydraulic model with different compliant models of artificial aorta was used for series of in-vitro experiments. The hydraulic model includes a piston pump that generates the waves. Our result indicates that wave propagation and reflection can create pumping mechanism in a compliant aorta. Similar to an impedance pump, the net flow and the flow direction depends on the frequency of the waves, compliance of the aorta, and the piston stroke.

  17. Near-diffraction-limited,35.4 W laser-diode end-pumped Nd:YVO4 slab laser operating at 1342 nm.

    Science.gov (United States)

    Yan, Ying; Zhang, Hengli; Liu, Yang; Yu, Xilong; Zhang, Huaijin; He, Jingliang; Xin, Jianguo

    2009-07-15

    A diode stack end-pumped Nd:YVO4 slab laser at 1342 nm with near-diffraction-limited beam quality by using a hybrid resonator was presented. At a pump power of 139.5 W, laser power of 35.4 W was obtained with a conversion efficiency of 25.4% of the laser diode to laser output. The beam quality M2 factors were measured to be 1.2 in the unstable direction and 1.3 in the stable direction at the output power of 29 W.

  18. The effects of surfactants on the lateral migration of bubbles and the bubble clustering phenomenon in a bubbly channel flow

    Science.gov (United States)

    Takagi, Shu; Ogasawara, Toshiyuki; Matsumoto, Yoichiro

    2004-11-01

    The behaviors of bubbles in an upward channel flow are experimentally investigated. Two kinds of surfactant, 3-pentanol and Triton X-100 are added in the bubbly flow. Addition of surfactant prevents the bubble coalescence and mono-dispersed 1mm spherical bubbles were obtained, although these surfactants do not modify the single-phase turbulence statistics. At the condition of high Reynolds number (Re=8200) with 20-60ppm 3-Pentanol, bubbles migrated towards the wall. These bubbles highly accumulated near the wall and formed crescent like shaped horizontal bubble clusters of 10-40mm length. On the other hand, bubble clusters did not appear in the 2ppm Triton-X100 aqueous solution. By the addition of the small amount of Triton-X100, bubble coalescences were also preventable and the bubble size and its distribution became almost the same as in the case of 60ppm 3-Pentanol aqueous solution. However, the tendency of the lateral migration of bubbles towards the wall weakened and the bubbles did not accumulated near the wall. And this is the main reason of the disapperance of bubble cluster. We discuss this phenomenon, related to the lift force acting on bubbles and particles.

  19. Simulating the thermal operating conditions in the thermal wells of ground-source heat-pump heat supply systems. Part I: Porous moisture freezing processes in soil

    Science.gov (United States)

    Vasilyev, G. P.; Peskov, N. V.; Lichman, V. A.; Gornov, V. F.; Kolesova, M. V.

    2015-08-01

    The mathematical models laid down in the new blocks of the INSOLAR.GSHP.12 software system simulating unsteady operating conditions of ground-source heat-pump (GSHP) heat supply systems are presented. The new model blocks take into account the effect the freezing of porous moisture in soil has on the GSHP system performance efficiency. Illustration is given to the need of taking into account the porous moisture freezing/thawing processes in soil, and the results from investigations devoted to the opening possibilities of constructing adaptive GSHP systems with controlled intensity of heat transfer in the soil-thermal well system are presented. The development of software simulating the porous moisture phase state variation processes in soil was preceded by development of mathematical equations representing the thermal conditions of soil body involving porous moisture freezing/thawing processes. A description of these equations is also given in the article. In constructing the mathematical model, the notion "effective thermal conductivity" of soil was introduced for taking into account the latent heat of phase transition that releases during the freezing of moisture. The above-mentioned effective thermal conductivity of soil involves two components: the soil thermal conductivity coefficient itself and an additional term modifying the thermal conductivity value for taking into account the influence of phase transition. For quantitatively evaluating the soil effective thermal conductivity component that takes into account the influence of phase transition, the soil freezing zone radius around the thermal well was determined. The obtained analytic solutions have been implemented in the form of computer program blocks, after which a "numerical experiment" was carried out for estimating the effect the porous moisture freezing/thawing processes have on the soil thermal conditions. It was demonstrated during that experiment that the soil thermal conductivities determined

  20. Cosmic Bubble Image Wins NRAO Contest

    Science.gov (United States)

    2006-10-01

    A striking image of an enormous bubble blown into the dusty gas disk of our own Milky Way galaxy has won first place in the National Radio Astronomy Observatory's second annual Radio Astronomy Image Contest. Dr. Jayanne English of the University of Manitoba led the team that made the winning image using data from the National Science Foundation's Very Large Array (VLA) in New Mexico and Robert C. Byrd Green Bank Telescope (GBT) in West Virginia. Cosmic Bubble Image Giant "Bubble" in Milky Way's Gas CREDIT: English et al., NRAO/AUI/NSF Click on image for large files and full information English and her collaborators Jeroen Stil and Russ Taylor, from the University of Calgary, will share the grand prize of $1,000 from Associated Universities, Inc., the research corporation that operates the observatory for the NSF. "We congratulate Dr. English for producing an outstanding image that beautifully illustrates the power of our radio telescopes," said NRAO Director Fred K.Y. Lo. The image contest is part of a broader NRAO effort to make radio astronomical data and images easily accessible and widely available to scientists, students, teachers, the general public, news media and science-education professionals. That effort includes an expanding image gallery on the observatory's Web site. English's winning image shows a giant bubble in the Milky Way's dusty gas disk. The bubble has been sculpted by the wind and radiation force from a few dozen hot, massive stars along with the explosive force of supernova explosions from dying stars. The bubble, seen in the faint radio glow of hydrogen gas, is some 30,000 light-years from Earth and measures 1,100 by 520 light-years. If the bubble, in the constellation Vulpecula, were visible to human eyes, it would appear to be eight times the diameter of the full Moon in the sky. The image was made using data collected as part of the VLA Galactic Plane Survey (VGPS), a set of systematic observations of the Milky Way. This survey, led by

  1. Measuring online social bubbles

    Directory of Open Access Journals (Sweden)

    Dimitar Nikolov

    2015-12-01

    Full Text Available Social media have become a prevalent channel to access information, spread ideas, and influence opinions. However, it has been suggested that social and algorithmic filtering may cause exposure to less diverse points of view. Here we quantitatively measure this kind of social bias at the collective level by mining a massive datasets of web clicks. Our analysis shows that collectively, people access information from a significantly narrower spectrum of sources through social media and email, compared to a search baseline. The significance of this finding for individual exposure is revealed by investigating the relationship between the diversity of information sources experienced by users at both the collective and individual levels in two datasets where individual users can be analyzed—Twitter posts and search logs. There is a strong correlation between collective and individual diversity, supporting the notion that when we use social media we find ourselves inside “social bubbles.” Our results could lead to a deeper understanding of how technology biases our exposure to new information.

  2. High Temperature Thermoacoustic Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Tijani, H.; Spoelstra, S. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2012-07-15

    Thermoacoustic technology can provide new types of heat pumps that can be deployed in different applications. Thermoacoustic heat pumps can for example be applied in dwellings to generate cooling or heating. Typically, space and water heating makes up about 60% of domestic and office energy consumption. The application of heat pumps can contribute to achieve energy savings and environmental benefits by reducing CO2 and NOx emissions. This paper presents the study of a laboratory scale thermoacoustic-Stirling heat pump operating between 10C and 80C which can be applied in domestics and offices. The heat pump is driven by a thermoacoustic-Stirling engine. The experimental results show that the heat pump pumps 250 W of heat at 60C at a drive ratio of 3.6 % and 200 W at 80C at a drive ratio of 3.5 %. The performance for both cases is about 40% of the Carnot performance. The design, construction, and performance measurements of the heat pump will be presented and discussed.

  3. Liquid hydrogen bubble chamber (diam. 30 cm), seen here being inserted into its vacuum tank

    CERN Multimedia

    CERN PhotoLab

    1959-01-01

    In the 1950s and 1960s, bubble and spark chambers were the dominant experimental tools in high-energy physics. While spark chambers were usually built and fitted to specific experiments, bubble chambers were constructed as general purpose devices that could be used for a variety of experiments. At CERN, the bubble chamber programme started under Charles Peyrou in the late 1950s. The first of CERN's bubble chambers, a 30 cm hydrogen chamber, is seen here being inserted into its vacuum tank. The HBC30, as it was called, took its first beam from the SC in 1959. One of the first pictures taken, of a positive pion-proton interaction, began a long series of pretty images for which bubble chambers would become famous. When it stopped operating in spring 1962, the HBC30 had consumed 150 km of film in its 3 years of operation.

  4. Introduction to Pump Rotordynamics

    Science.gov (United States)

    2006-11-01

    RTO-EN-AVT-143 9 - 1 Introduction to Pump Rotordynamics Luis San Andrés Mast-Childs Tribology Professor Turbomachinery Laboratory Texas A... rotordynamics of turbomachinery, excessive vibration and instability. The acceptable performance of a turbomachine depends on the adequate design and operation...on rotordynamics . The basic equations for the modeling of linear rotor-bearing systems are given along with an example for the rotordynamics of a

  5. Experimental investigation and numerical analysis of unsteady attached sheet-cavitating flows in a centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    LIU Hou-lin; LIU Dong-xi; WANG Yong; WU Xian-fang; WANG Jian; DU Hui

    2013-01-01

    This paper studies the attached sheet cavitation in centrifugal pumps.A pump casted from Perspex is used as the test subject.The cavitation bubbles were observed in the entrance of the impeller and the drops of the head coefficients were measured under different operating conditions.A Filter-Based Model (FBM),derived from the RNG k-ε model,and a modified Zwart model are adopted in the numerical predictions of the unsteady cavitating flows in the pump.The simulations are carried out and the results are compared with experimental results for 3 different flow coefficients,from 0.077 to 0.114.Under four operating conditions,qualitative comparisons are made between experimental and numerical cavitation patterns,as visualized by a high-speed camera and described as isosurfaces of the vapour volume fraction αv =0.1.It is shown that the simulation can truly represent the development of the attached sheet cavitation in the impeller.At the same time,the curves for the drops of the head coefficients obtained from experiments and calculations are also quantitatively compared,which shows that the decline of the head coefficients at every flow coefficient is correctly captured,and the prediction accuracy is high.In addition,the detailed analysis is made on the vapour volume fraction contours on the plane of span is 0.5 and the loading distributions around the blade section at the midspan.It is shown that the FBM model and the modified Zwart model are effective for the numerical simulation of the cavitating flow in centrifugal pumps.The analysis results can also be used as the basis for the further research of the attached sheet cavitation and the improvement of centrifugal pumps.

  6. FEASTING BLACK HOLE BLOWS BUBBLES

    Science.gov (United States)

    2002-01-01

    A monstrous black hole's rude table manners include blowing huge bubbles of hot gas into space. At least, that's the gustatory practice followed by the supermassive black hole residing in the hub of the nearby galaxy NGC 4438. Known as a peculiar galaxy because of its unusual shape, NGC 4438 is in the Virgo Cluster, 50 million light-years from Earth. These NASA Hubble Space Telescope images of the galaxy's central region clearly show one of the bubbles rising from a dark band of dust. The other bubble, emanating from below the dust band, is barely visible, appearing as dim red blobs in the close-up picture of the galaxy's hub (the colorful picture at right). The background image represents a wider view of the galaxy, with the central region defined by the white box. These extremely hot bubbles are caused by the black hole's voracious eating habits. The eating machine is engorging itself with a banquet of material swirling around it in an accretion disk (the white region below the bright bubble). Some of this material is spewed from the disk in opposite directions. Acting like high-powered garden hoses, these twin jets of matter sweep out material in their paths. The jets eventually slam into a wall of dense, slow-moving gas, which is traveling at less than 223,000 mph (360,000 kph). The collision produces the glowing material. The bubbles will continue to expand and will eventually dissipate. Compared with the life of the galaxy, this bubble-blowing phase is a short-lived event. The bubble is much brighter on one side of the galaxy's center because the jet smashed into a denser amount of gas. The brighter bubble is 800 light-years tall and 800 light-years across. The observations are being presented June 5 at the American Astronomical Society meeting in Rochester, N.Y. Both pictures were taken March 24, 1999 with the Wide Field and Planetary Camera 2. False colors were used to enhance the details of the bubbles. The red regions in the picture denote the hot gas

  7. Method for controlling powertrain pumps

    Science.gov (United States)

    Sime, Karl Andrew; Spohn, Brian L; Demirovic, Besim; Martini, Ryan D; Miller, Jean Marie

    2013-10-22

    A method of controlling a pump supplying a fluid to a transmission includes sensing a requested power and an excess power for a powertrain. The requested power substantially meets the needs of the powertrain, while the excess power is not part of the requested power. The method includes sensing a triggering condition in response to the ability to convert the excess power into heat in the transmission, and determining that an operating temperature of the transmission is below a maximum. The method also includes determining a calibrated baseline and a dissipation command for the pump. The calibrated baseline command is configured to supply the fluid based upon the requested power, and the dissipation command is configured to supply additional fluid and consume the excess power with the pump. The method operates the pump at a combined command, which is equal to the calibrated baseline command plus the dissipation command.

  8. Experimental and numerical study on bubble-sphere interaction near a rigid wall

    Science.gov (United States)

    Li, S.; Zhang, A. M.; Han, R.; Liu, Y. Q.

    2017-09-01

    This study is concerned with the interaction between a violently oscillating bubble and a movable sphere with comparable size near a rigid wall, which is an essential physical phenomenon in many applications such as cavitation, underwater explosion, ultrasonic cleaning, and biomedical treatment. Experiments are performed in a cubic water tank, and the underwater electric discharge technique (580 V DC) is employed to generate a bubble that is initiated between a rigid wall and a sphere in an axisymmetric configuration. The bubble-sphere interactions are captured using a high-speed camera operating at 52 000 frames/s. A classification of the bubble-sphere interaction is proposed, i.e., "weak," "intermediate," and "strong" interactions, identified with three distinct bubble shapes at the maximum volume moment. In the numerical simulations, the boundary integral method and the auxiliary function method are combined to establish a full coupling model that decouples the mutual dependence between the force and the sphere motion. The main features of bubble dynamics in different experiments are well reproduced by our numerical model. Meanwhile, the pressure and velocity fields are also provided for clarifying the associated mechanisms. The effects of two dimensionless standoff parameters, namely, γs (defined as ds/Rm, where ds is the minimum distance between the initial bubble center and the sphere surface and Rm is the maximum bubble radius) and γw (defined as dw/Rm, where dw is the distance between the initial bubble center and the rigid wall), are also discussed.

  9. Sonoluminescence and multi-bubble cavitation phenomena for selected research and industrial applications

    Science.gov (United States)

    Greenwood, Larry; Olsen, Khris; Good, Morris; Bond, Leonard; Posakony, Gerald; Peters, Timothy; Baldwin, David; Wester, Dennis; Ahmed, Salahuddin

    2003-04-01

    Single bubble sonoluminescence (SBSL), multi-bubble sonoluminescence (MBSL), multi-bubble sonochemiluminescence (MBSCL) and other high power ultrasound cavitation and noncavitating ultrasound process stream interaction phenomena are known to produce a wide range of both physical and chemical effects that depend upon the system and operating conditions employed. Three interacting regimes are under investigation (a) high power and high frequency (including noncavitating systems), (b) single bubble resonance/sonoluminescence and (c) multi-bubble high power sonochemical processing. In all cases these involve various reactors, including possible schemes for continuous material feeding and processing for selected chemical, nonaqueous fluids and biological research and industrial applications. High power sonochemical and noncavitating ultrasound processing applications and a review of literature pertaining to the potential of high power processing, including fusion are discussed. Work includes the investigation of acoustic fields in reactors, characterization of sonoluminescence spectra, the investigation of system parameters to control maximum bubble temperature and pressure, and acoustic energy partition into light and acoustic emission/shock waves. Effects of various chemical systems on multi-bubble luminescence are being investigated and will be reported. Work to date has emphasized the evaluation of both single and multi-bubble sonoluminescence, spectral measurements, acoustic emission measurements and the observation of a continuous bubble feed phenomenon.

  10. Bubble shape and breakage events in a vertical pipe at the boiler flow line

    Directory of Open Access Journals (Sweden)

    Fsadni Andrew

    2014-03-01

    Full Text Available The theoretical and experimental aspects concerning the typical bubble shape at the flow line of a standard domestic central heating system are investigated. This is done in support of the on-going research on two-phase flows in domestic central heating systems. Bubble nucleation and detachment at the primary heat exchanger wall of a domestic central heating boiler results in a bubbly two-phase flow in the system pipe work. Bubbly flow results in undesired cold spots at higher points in the system, consequently diminishing system performance. An experimental analysis was done on the bubble shape at the exit of the boiler through the application of photographic techniques. The results are presented in terms of the measured bubble aspect ratios at some principal system operating conditions. The dimensionless Eotvos and bubble Reynolds number were calculated and tabulated with the measured mean diameters. The data was subsequently correlated to the bubble shape regime diagram. Results suggest that most bubbles are quasi-spherical in shape with a noticeable elongation at lower bulk fluid Reynolds numbers.

  11. Bubble shape and breakage events in a vertical pipe at the boiler flow line

    Science.gov (United States)

    Fsadni, Andrew; Ge, Yunting

    2014-03-01

    The theoretical and experimental aspects concerning the typical bubble shape at the flow line of a standard domestic central heating system are investigated. This is done in support of the on-going research on two-phase flows in domestic central heating systems. Bubble nucleation and detachment at the primary heat exchanger wall of a domestic central heating boiler results in a bubbly two-phase flow in the system pipe work. Bubbly flow results in undesired cold spots at higher points in the system, consequently diminishing system performance. An experimental analysis was done on the bubble shape at the exit of the boiler through the application of photographic techniques. The results are presented in terms of the measured bubble aspect ratios at some principal system operating conditions. The dimensionless Eotvos and bubble Reynolds number were calculated and tabulated with the measured mean diameters. The data was subsequently correlated to the bubble shape regime diagram. Results suggest that most bubbles are quasi-spherical in shape with a noticeable elongation at lower bulk fluid Reynolds numbers.

  12. A microfluidic two-pump system inspired by liquid feeding in mosquitoes

    Science.gov (United States)

    Marino, Andrew; Goad, Angela; Stremler, Mark; Socha, John; Jung, Sunghwan

    Mosquitoes feed on nectar and blood using a two-pump system in the head-a smaller cibarial pump in line with a larger a pharyngeal pump, with a valve in between. To suck, mosquitoes transport the liquid (which may be a multi-component viscous fluid, blood) through a long micro-channel, the proboscis. In the engineering realm, microfluidic devices in biomedical applications, such as lab-on-a-chip technology, necessitate implementing a robust pump design to handle clogging and increase flow control compared to a single-pump system. In this talk, we introduce a microfluidic pump design inspired by the mosquito's two-pump system. The pumping performance (flow rate) in presence of impurities (air bubbles, soft clogs) is quantified as a function of phase difference and volume expansion of the pumps, and the elasticity of the valve.

  13. Bubble sorting in pinched microchannels for ultrasound contrast agent enrichment

    NARCIS (Netherlands)

    Kok, M.P.; Segers, T.J.; Versluis, M.

    2015-01-01

    Ultrasound contrast agent (UCA) suspensions contain encapsulated microbubbles with a wide size distribution, with radii between 1 and 10 μm. Medical transducers generally operate at a narrow frequency bandwidth, severely limiting the fraction of bubbles that resonates to the driving ultrasound. Thus

  14. Microbubbles are detected prior to larger bubbles following decompression.

    Science.gov (United States)

    Swan, J G; Wilbur, J C; Moodie, K L; Kane, S A; Knaus, D A; Phillips, S D; Beach, T L; Fellows, A M; Magari, P J; Buckey, J C

    2014-04-01

    Using dual-frequency ultrasound (DFU), microbubbles (multiple sites, 2) appear in the presence and absence of bmdVGE, and 3) occur before bmdVGE. This supports the hypothesis that microbubbles precede larger VGE bubbles. Microbubble presence may be an early marker of decompression stress. Since DFU is a low-power ultrasonic method, it may be useful for operational diving applications.

  15. Optimized ground coupled heat pump mechanical package

    Energy Technology Data Exchange (ETDEWEB)

    Catan, M.A.

    1987-01-01

    This project addresses the question of how well a ground coupled heat pump system could perform with a heat pump which was designed specifically for such systems operating in a northern climate. Conventionally, systems are designed around water source heat pumps which are not designed for ground coupled heat pump application. The objective of the project is to minimize the life cycle cost for a ground coupled system given the freedom to design the heat pump and the ground coil in concert. In order to achieve this objective a number of modeling tools were developed which will likely be of interest in their own right.

  16. Pump control system for windmills

    Science.gov (United States)

    Avery, Don E.

    1983-01-01

    A windmill control system having lever means, for varying length of stroke of the pump piston, and a control means, responsive to the velocity of the wind to operate the lever means to vary the length of stroke and hence the effective displacement of the pump in accordance with available wind energy, with the control means having a sensing member separate from the windmill disposed in the wind and displaceable thereby in accordance with wind velocity.

  17. Operation strategy of solar-ground source heat pump systems%太阳能-地源热泵联合供能系统运行策略研究

    Institute of Scientific and Technical Information of China (English)

    王恩宇; 贺芳; 齐承英

    2012-01-01

    根据天津地区的气候条件,建立了太阳能-地源热泵多热源供热系统模型.利用TRNSYS软件对该系统进行了模拟研究,分析了系统用能情况及运行过程中地温的变化,着重对运行策略进行了研究.基于系统的性能系数选定的控制策略为:集热器出口与水箱出口温差大于15℃时启动集热,当温差小于2℃时停止集热;水箱出口温度高于50℃时启动储热,土壤进出口水温差不足5℃时停止储热.%Establishes a solar-ground source heat pump system model according to the climatic conditions in Tianjin. Carries out a simulation study of the system based on TRNSYS program, analyses the energy consumption of the system and the ground temperature change, and studies the operation strategy with emphasis. Selects an appropriate operation strategy based on the coefficient of performance (COP) of system, i. e. to turn on the solar collection pump as the temperature difference between collector outlet and tank outlet is higher than 15 ℃, and to turn off the pump until it is less than 2 ℃ , and to turn on the solar storage pump when tank outlet temperature is higher than 50 ℃ , and to turn off it until the temperature difference between inlet and outlet of the borehole heat exchanger is less than 5 ℃.

  18. Soil-Temperature Monitoring and Analysis of a Ground Source Heat Pump System During the Operating Period%地埋管地源热泵系统运行期地温监测与分析

    Institute of Scientific and Technical Information of China (English)

    王小清; 王万忠

    2013-01-01

      以上海地区某工程为例,通过设置地温监测系统并对地温进行监测,根据监测结果和地源热泵系统运行情况,对地埋管地源系统运行期地温场的变化特征进行分析研究。结果表明:换热区地温变化与地源热泵系统的运行情况相关,呈现规律性的变化;经过一个运行年度,换热区的地温场能够基本恢复至原始状态;系统运行对换热区外围区域地温场的影响范围有限。研究成果可为浅层地温能的开发利用提供技术支持。%  This paper reports the results of a soil-temperature monitoring project in the Shanghai area. A soil-temperature monitoring system was installed to monitor fluctuations in soil temperature. Measurements of temperature and of the operating status of the ground source heat pump system indicate that the soil temperature field in the ground-coupled heat pump system varied during the operating period. The results show that the soil temperature distribution in the heat exchanger is associated with the operation of the ground source heat pump (GSHP) system. After one year of operation, the soil temperature distribution in the heat exchanger returns essential y to the original condition. The running of a GSHP system cannot affect temperature changes outside the heat exchanger. The results should provide technical support for the development and utilization of shal ow geothermal resources.

  19. Bubble-sort图和Modified Bubble-sort图的自同构群%Automorphism Groups of Bubble-sort Graphs and Modified Bubble-sort Graphs

    Institute of Scientific and Technical Information of China (English)

    张昭; 黄琼湘

    2005-01-01

    Bubble-sort graphs and modified bubble-sort graphs are two classes of Cayley graphs which are widely studied for their application in network construction. In this paper, we determine the full automorphism groups of bubble-sort graphs and modified bubble-sort graphs.%Bubble-Sort图和Modified Bubble-Sort图是两类特殊的Cayley图,由于其在网络构建中的应用而受到广泛关注.本文完全确定了这两类图的自同构群.

  20. Spherical Solutions of an Underwater Explosion Bubble

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw

    1998-01-01

    Full Text Available The evolution of the 1D explosion bubble flow field out to the first bubble minimum is examined in detail using four different models. The most detailed is based on the Euler equations and accounts for the internal bubble fluid motion, while the simplest links a potential water solution to a stationary, Isentropic bubble model. Comparison of the different models with experimental data provides insight into the influence of compressibility and internal bubble dynamics on the behavior of the explosion bubble.

  1. Operating experience in the gasification of municipal waste and other waste at the `secondary feedstocks recycling centre` (SVZ) Schwarze Pumpe; Betriebserfahrungen zur Vergasung von Hausmuell und anderen Abfaellen im Sekundaerrohstoffverwertungszentrum Schwarze Pumpe (SVZ)

    Energy Technology Data Exchange (ETDEWEB)

    Buttker, B. [Sekundaerrohstoffverwertungszentrum Schwarze Pumpe GmbH, Schwarze Pumpe (Germany)

    1998-12-31

    The business purpose of SVZ Schwarze Pumpe is the production of synthesis gas from hydro-carbon-containing waste material and the use of synthesis gas in gas production or energy generation. For synthesis gas production, the techniques of packed-bed pressure gasification (FDV) and entrained-flow gasification (FSV) are used in close interconnection. Process control is such that only inert slags accrue, apart from the final products methanol and gypsum as well as generated energy in the form of electricity, process steam and heat. Currently, the following materials are mainly used in gasification: plastic materials after being subjected to conditioning, industrial and municipal sewage sludge, shredded goods, contaminated used wood, contaminated used oil, oil components obtained from oil/water mixtures, and slurry products. A special in-house know-how for waste oil gasification, and for the combined gasification of solid waste and coal by packed-bed pressure gasification with gradual stepping-up of the waste portion was realized. (orig.) [Deutsch] Der Geschaetszweck des SVZ Schwarze Pumpe besteht in der Herstellung von Synthesegas aus kohlenwasserstoffhaltigen Einsatzstoffen und in der stofflichen und energetischen Nutzung des Wertstoffes Synthesegas. Zur Synthesegasgewinnung werden die Verfahren der Festbettdruckvergasung (FDV) und Flugstromvergasung (FSV) in einer engen verbundwirtschaftlichen Kopplung angewandt. Die Betriebsfuehrung ist so gestaltet, dass neben den Endprodukten Methnaol und Gips sowie erzeugter Energie in Form von Strom, Prozessdampf und Waerme nur noch inerte Schlacken entstehen. Die Haupteinsatzprodukte fuer die Vergasung sind ggw. aufbereitete Altkunststoffe, industrielle und kommunale Klaerschlaemme, Shreddergueter, kontaminiertes Altholz, kontaminierte Altoele, Oelkomponenten, die aus Oel-Wasser-Gemischen gewonnen werden, und Slurry-Produkte. Es wurde ein spezielles Betriebs-Know-how zur Abfalloel-Vergasung und zur kombinierten Vergasung

  2. Bubble-bubble interaction: A potential source of cavitation noise

    CERN Document Server

    Ida, Masato

    2009-01-01

    The interaction between microbubbles through pressure pulses has been studied to show that it can be a source of cavitation noise. A recent report demonstrated that the acoustic noise generated by a shrimp originates from the collapse of a cavitation bubble produced when the shrimp closes its snapper claw. The recorded acoustic signal contains a broadband noise that consists of positive and negative pulses, but a theoretical model for single bubbles fails to reproduce the negative ones. Using a nonlinear multibubble model we have shown here that the negative pulses can be explained by considering the interaction of microbubbles formed after the cavitation bubble has collapsed and fragmented: Positive pulses produced at the collapse of the microbubbles hit and impulsively compress neighboring microbubbles to generate reflected pulses whose amplitudes are negative. Discussing the details of the noise generation process, we have found that no negative pulses are generated if the internal pressure of the reflecti...

  3. A dynamic pressure view cell for acoustic stimulation of fluids—Micro-bubble generation and fluid movement in porous media

    Science.gov (United States)

    Stewart, Robert A.; Shaw, J. M.

    2015-09-01

    The development and baseline operation of an acoustic view cell for observing fluids, and fluid-fluid and fluid-solid interfaces in porous media over the frequency range of 10-5000 Hz is described. This range includes the industrially relevant frequency range 500-5000 Hz that is not covered by existing devices. Pressure waveforms of arbitrary shape are generated in a 17.46 mm ID by 200 mm and 690.5 mm long glass tubes at flow rates up to 200 ml/min using a syringe pump. Peak-to-peak amplitudes exceeding 80 kPa are readily realized at frequencies from 10 to 5000 Hz in bubble free fluids when actuated with 20 Vpp as exemplified using castor oil. At resonant frequencies, peak-to-peak pressure amplitudes exceeding 500 kPa were obtained (castor oil at 2100 Hz when actuated with 20 Vpp). Impacts of vibration on macroscopic liquid-liquid and liquid-vapour interfaces and interface movement are illustrated. Pressure wave transmission and attenuation in a fluid saturated porous medium, randomly packed 250-330 μm spherical silica beads, is also demonstrated. Attenuation differences and frequency shifts in resonant peaks are used to detect the presence and generation of dispersed micro-bubbles (visualized. Envisioned applications include assessment of the impacts of vibration on reaction, mass transfer, and flow/flow pattern outcomes. This knowledge will inform laboratory and pilot scale process studies, where nuisance vibrations may affect the interpretation of process outcomes, and large scale or in situ processes in aquifers or hydrocarbon reservoirs where imposed vibration may be deployed to improve aspects of process performance. Future work will include miscible interface observation and quantitative measurements in the bulk and in porous media where the roles of micro-bubbles comprise subjects of special interest.

  4. Mixing high-viscosity fluids via acoustically driven bubbles

    Science.gov (United States)

    Orbay, Sinem; Ozcelik, Adem; Lata, James; Kaynak, Murat; Wu, Mengxi; Huang, Tony Jun

    2017-01-01

    We present an acoustofluidic micromixer which can perform rapid and homogeneous mixing of highly viscous fluids in the presence of an acoustic field. In this device, two high-viscosity polyethylene glycol (PEG) solutions were co-injected into a three-inlet PDMS microchannel with the center inlet containing a constant stream of nitrogen flow which forms bubbles in the device. When these bubbles were excited by an acoustic field generated via a piezoelectric transducer, the two solutions mixed homogenously due to the combination of acoustic streaming, droplet ejection, and bubble eruption effects. The mixing efficiency of this acoustofluidic device was evaluated using PEG-700 solutions which are ~106 times more viscous than deionized (DI) water. Our results indicate homogenous mixing of the PEG-700 solutions with a ~0.93 mixing index. The acoustofluidic micromixer is compact, inexpensive, easy to operate, and has the capacity to mix highly viscous fluids within 50 ms.

  5. Bubble entrainment, spray and splashing at hydraulic jumps

    Institute of Scientific and Technical Information of China (English)

    CHANSON Hubert

    2006-01-01

    The sudden transition from a high-velocity, supercritical open channel flow into a slow-moving sub-critical flow is a hydraulic jump. Such a flow is characterised by a sudden rise of the free-surface, with some strong energy dissipation and air entrainment, waves and spray. New two-phase flow measurements were performed in the developing flow region using a large-size facility operating at large Reynolds numbers. The experimental results demonstrated the complexity of the flow with a developing mixing layer in which entrained bubbles are advected in a high shear stress flow. The relationship between bubble count rates and void fractions was non-unique in the shear zone, supporting earlier observations of some form of double diffusion process between momentum and air bubbles. In the upper region, the flow consisted primarily of water drops and packets surrounded by air. Visually significant pray and splashing were significant above the jump roller. The present study is the first comprehensive study detailing the two-phase flow properties of both the bubbly and spray regions of hydraulic jumps, a first step towards understanding the interactions between bubble entrainment and droplet ejection processes.

  6. Operative strategies to reduce cerebral embolic events during on- and off-pump coronary artery bypass surgery: A stratified, prospective randomized trial.

    Science.gov (United States)

    Halkos, Michael E; Anderson, Aaron; Binongo, Jose Nilo G; Stringer, Anthony; Lasanajak, Yi; Thourani, Vinod H; Lattouf, Omar M; Guyton, Robert A; Baio, Kim T; Sarin, Eric; Keeling, William B; Cook, N Renee; Carssow, Katherine; Neill, Alexis; Glas, Kathryn E; Puskas, John D

    2017-10-01

    To determine the impact of different aortic clamping strategies on the incidence of cerebral embolic events during coronary artery bypass grafting (CABG). Between 2012 and 2015, 142 patients with low-grade aortic disease (epiaortic ultrasound grade I/II) undergoing primary isolated CABG were studied. Those undergoing off-pump CABG were randomized to a partial clamp (n = 36) or clampless facilitating device (CFD; n = 36) strategy. Those undergoing on-pump CABG were randomized to a single-clamp (n = 34) or double-clamp (n = 36) strategy. Transcranial Doppler ultrasonography (TCD) was performed to identify high-intensity transient signals (HITS) in the middle cerebral arteries during periods of aortic manipulation. Neurocognitive testing was performed at baseline and 30-days postoperatively. The primary endpoint was total number of HITS detected by TCD. Groups were compared using the Mann-Whitney U test. In the off-pump group, the median number of total HITS were higher in the CFD subgroup (30.0; interquartile range [IQR], 22-43) compared with the partial clamp subgroup (7.0; IQR, 0-16; P 1 CFD (12.5 [IQR, 4-19] vs 36.0 [IQR, 25-47]; P = .001). In the on-pump group, the median number of total HITS was 10.0 (IQR, 3-17) in the single-clamp group, compared with 16.0 (IQR, 4-49) in the double-clamp group (P = .10). There were no differences in neurocognitive outcomes across the groups. For patients with low-grade aortic disease, the use of CFDs was associated with an increased rate of cerebral embolic events compared with partial clamping during off-pump CABG. A single-clamp strategy during on-pump CABG did not significantly reduce embolic events compared with a double-clamp strategy. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  7. Quantum Bubble Nucleation beyond WKB Resummation of Vacuum Bubble Diagrams

    CERN Document Server

    Suzuki, H; Suzuki, Hiroshi; Yasuta, Hirofumi

    1998-01-01

    On the basis of Borel resummation, we propose a systematical improvement of bounce calculus of quantum bubble nucleation rates. We study a metastable super-renormalizable field theory, D dimensional O(N) symmetric \\phi^4 model (D<4) with an attractive interaction. The validity of our proposal is tested in D=1 (quantum mechanics) by using the perturbation series of ground state energy to high orders. We also present a result in D=2 based on an explicit calculation of vacuum bubble diagrams to five loop orders.

  8. 基于蚁群算法的泵站运行优化及投影寻踪选优策略%Pump Operation Optimization and Projection Pursuit Evaluation Strategy Based on Ant Colony Optimization

    Institute of Scientific and Technical Information of China (English)

    袁尧; 刘超

    2013-01-01

    针对泵站优化运行计算时最优解评价指标单一的问题,建立了包含机组开停机约束的泵站优化运行数学模型和运行方案选优的投影寻踪决策模型.提出了求解泵站多机组优化运行模型的蚁群算法,并通过分析模型的特性改进了算法中启发式信息和信息素更新方式.对江都四站多机组日优化运行计算的结果显示,变量同等离散的情况下,利用蚁群算法优化的结果比用动态规划逐次逼近法优化的结果节省了2.8%的电费,前者相比设计工况运行时节省了29.2%的电费,且蚁群算法优化结果对应的运行方案中叶片调节次数少,机组运行时间短;方案选优时投影寻踪决策模型能够兼顾多个评价指标的优选,得到的运行方案不仅运行成本低,且更合理,更贴切于日常运行,可见改进后的蚁群算法结合投影寻踪决策模型在泵站优化运行及相近的领域有较大的实用价值.%Usually the evaluation index of optimal pump operation solution is single. An optimal pump operation model which contained the constraint of start-stop pump unit was developed, and projection pursuit evaluation method for scheme optimization was proposed. The ant colony optimization algorithm was used to calculate the model. The heuristic information and the pheromone trail update method were improved by analyzing characters of the model for better performances. A calculation example for the No. 4 Jiangdu pumping station was conducted. The results from ant colony optimization algorithm showed that 29. 2% of energy fee could be saved under the designed operation condition, which was compared with the result from dynamic programming with successive approximation algorithm under the same discrete condition, and was better with 2. 8% of the result from dynamic programming. The results from ant colony optimization algorithm had less times of the blade adjusting, and shorter operating time of the pumps

  9. How safe is Bubble Soccer?

    Science.gov (United States)

    Halani, Sameer H; Riley, Jonathan P; Pradilla, Gustavo; Ahmad, Faiz U

    2016-12-01

    Traumatic neurologic injury in contact sports is a rare but serious consequence for its players. These injuries are most commonly associated with high-impact collisions, for example in football, but are found in a wide variety of sports. In an attempt to minimize these injuries, sports are trying to increase safety by adding protection for participants. Most recently is the seemingly 'safe' sport of Bubble Soccer, which attempts to protect its players with inflatable plastic bubbles. We report a case of a 16-year-old male sustaining a cervical spine burst fracture with incomplete spinal cord injury while playing Bubble Soccer. To our knowledge, this is the first serious neurological injury reported in the sport.

  10. Bursting Bubbles and Bilayers

    Directory of Open Access Journals (Sweden)

    Steven P. Wrenn, Stephen M. Dicker, Eleanor F. Small, Nily R. Dan, Michał Mleczko, Georg Schmitz, Peter A. Lewin

    2012-01-01

    Full Text Available This paper discusses various interactions between ultrasound, phospholipid monolayer-coated gas bubbles, phospholipid bilayer vesicles, and cells. The paper begins with a review of microbubble physics models, developed to describe microbubble dynamic behavior in the presence of ultrasound, and follows this with a discussion of how such models can be used to predict inertial cavitation profiles. Predicted sensitivities of inertial cavitation to changes in the values of membrane properties, including surface tension, surface dilatational viscosity, and area expansion modulus, indicate that area expansion modulus exerts the greatest relative influence on inertial cavitation. Accordingly, the theoretical dependence of area expansion modulus on chemical composition - in particular, poly (ethylene glyclol (PEG - is reviewed, and predictions of inertial cavitation for different PEG molecular weights and compositions are compared with experiment. Noteworthy is the predicted dependence, or lack thereof, of inertial cavitation on PEG molecular weight and mole fraction. Specifically, inertial cavitation is predicted to be independent of PEG molecular weight and mole fraction in the so-called mushroom regime. In the “brush” regime, however, inertial cavitation is predicted to increase with PEG mole fraction but to decrease (to the inverse 3/5 power with PEG molecular weight. While excellent agreement between experiment and theory can be achieved, it is shown that the calculated inertial cavitation profiles depend strongly on the criterion used to predict inertial cavitation. This is followed by a discussion of nesting microbubbles inside the aqueous core of microcapsules and how this significantly increases the inertial cavitation threshold. Nesting thus offers a means for avoiding unwanted inertial cavitation and cell death during imaging and other applications such as sonoporation. A review of putative sonoporation mechanisms is then presented

  11. 太中银铁路沿线站区地源热泵运行与维护管理%On operation of ground source heat pump and maintenance management at stations along Taiyuan-Zhongwei-Yinchuan Railway

    Institute of Scientific and Technical Information of China (English)

    廉小洁

    2015-01-01

    在对地源热泵工作理论分析的基础上,结合太中银铁路太原局管段五站地埋管地源热泵实际使用中存在的管路断裂、换热量不足等问题,从系统运行与维护管理角度提出了一些改进建议,为地埋管地源热泵系统的推广应用提供了技术支持。%Based on the theoretic analysis of the ground source heat pump,the paper points out some improvement suggestions from the system op-eration and maintenance by combining with pipeline fracture,shortage of heat problems in the uses of the ground source heat pump at the five sta-tion of Taiyuan Bureau Segment along Taiyuan-Zhongwei-Yinchuan Railway,so as to provide some technical support for the application of the bur-ied ground source heat pump system.

  12. Passive acoustic derived bubble flux and applications to natural gas seepage in the Mackenzie Delta, NWT, Canada and Coal Oil Point, CA

    Science.gov (United States)

    Culling, D.; Leifer, I.; Dallimore, S.; Alcala, K.

    2012-12-01

    Methane is a prominent greenhouse gas that escapes naturally from thermogenic reservoirs as seepage from marine and lacustrine biogenic sources as bubble ebullition. Geologic methane emissions are critically important contributors to the global methane budget however, few quantitative flux measurements are available for shallow waters. This gap in knowledge is critical as in these settings gas can easily transit as bubbles through the water column and directly influence global atmospheric budgets. Video and active acoustic (sonar) measurements of bubble flux have spatial limitations requiring predictable bubble emission location. Passive acoustics are less affected by these limitations, in addition, they can provide data in water too shallow for effective sonar bubble observations. Lab tests were undertaken to quantify the acoustic signature of bubbles formed in non-cohesive sediments. specifically focusing on mechanisms that complicate interpretation of acoustic data. Lab tests then were compared to field data to provide measurement calibration/validation. The principles behind the acoustic analysis method are based on the Minnaert equation, which relates a bubble radius and acoustic frequency. Bubble size and the resultant acoustic frequency from known flows and capillary tube diameters are well documented; however changing sediment pathways adds to the complexity of bubble formation and the resultant bubble acoustic signal. These complex signals were investigated in a lab tank with a thick, cohesive fine-grained sediment bed, through which bubbles produced by a syringe pump migrated to the sediment-water interface. Then, the resultant bubbles were diverted into clear water and measured from high speed, high definition video, while the acoustic signature of bubble formation was recorded concurrently by a hydrophone. Bubble formation is influenced by currents, which shifts the acoustical signal towards a higher frequency with a more complex pattern than the

  13. First Demonstration of a Scintillating Xenon Bubble Chamber for Detecting Dark Matter and Coherent Elastic Neutrino-Nucleus Scattering

    Science.gov (United States)

    Baxter, D.; Chen, C. J.; Crisler, M.; Cwiok, T.; Dahl, C. E.; Grimsted, A.; Gupta, J.; Jin, M.; Puig, R.; Temples, D.; Zhang, J.

    2017-06-01

    A 30-g xenon bubble chamber, operated at Northwestern University in June and November 2016, has for the first time observed simultaneous bubble nucleation and scintillation by nuclear recoils in a superheated liquid. This chamber is instrumented with a CCD camera for near-IR bubble imaging, a solar-blind photomultiplier tube to detect 175-nm xenon scintillation light, and a piezoelectric acoustic transducer to detect the ultrasonic emission from a growing bubble. The time of nucleation determined from the acoustic signal is used to correlate specific scintillation pulses with bubble-nucleating events. We report on data from this chamber for thermodynamic "Seitz" thresholds from 4.2 to 15.0 keV. The observed single- and multiple-bubble rates when exposed to a Cf 252 neutron source indicate that, for an 8.3-keV thermodynamic threshold, the minimum nuclear recoil energy required to nucleate a bubble is 19 ±6 keV (1 σ uncertainty). This is consistent with the observed scintillation spectrum for bubble-nucleating events. We see no evidence for bubble nucleation by gamma rays at any of the thresholds studied, setting a 90% C.L. upper limit of 6.3 ×10-7 bubbles per gamma interaction at a 4.2-keV thermodynamic threshold. This indicates stronger gamma discrimination than in CF3 I bubble chambers, supporting the hypothesis that scintillation production suppresses bubble nucleation by electron recoils, while nuclear recoils nucleate bubbles as usual. These measurements establish the noble-liquid bubble chamber as a promising new technology for the detection of weakly interacting massive particle dark matter and coherent elastic neutrino-nucleus scattering.

  14. Fine bubble generator and method

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, P.M.; Koros, R.M.

    1990-10-09

    This patent describes a method of forming fine gaseous bubbles in a liquid ambient. It comprises: forcing a gas through orifices located in the liquid ambient while simultaneously forcing a liquid through liquid orifices at a velocity sufficient to form jet streams of liquid, the liquid orifices being equal in number to the gas orifices and so oriented that each jet stream of liquid intersects the gas forced through each gas orifice and creates sufficient turbulence where the gas and jet stream of liquid intersect, whereby fine gaseous bubbles are formed.

  15. Probabilistic assessment of night pumping operation of flammable fluids and pressure testing with maritime diesel; Analise probabilisica de seguranca para as operacoes de bombeio noturno de inflamaveis e teste de pressao com diesel maritimo

    Energy Technology Data Exchange (ETDEWEB)

    Jacinto, Carlos M.C.; Barbosa, Valdir P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Garcia, Pauli A.A. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Ramos, Fernando A.

    2008-07-01

    Some operations, due to unscientific knowledge, have been prohibited in E and P activities. Among these operations one have night pumping of flammable fluid and pressure test with maritime diesel. For this reason one has a considerable lost of time due to the necessity to wait until the morning of the day after, in case of night pumping, or due to logistic skills concerning the difficulties to obtain materials which can be adopted in place of the maritime diesel. In turn to verify, scientifically, funding on a probabilistic safety analysis, the present paper present a hybrid approach, due to the high complexity of the considered scenario. In this hybrid approach, one has: HAZOP, event trees, Bayesian network, fault trees, and Bayesian inference for expert opinions estimation. The obtained results are satisfactory haven in view that they show the probability of occurrence of a catastrophic event concerning the analyzed operations. The obtained results are very satisfactory due to the fact that the one have obtained the probability values of undesirable events, and these values can be compared to the reference one. These reference figures are known as ALARP and are proposed by HSE. (author)

  16. Bubble Content in Air/Hydro System--Part 1:Measurement of Bubble Content

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mechanism of bubble formation in air/hydro systems is investigated. Results presented in this paper include further insight into the mechanism of bubble formation and the measurement of bubble content. The regularity of bubble transport in the system is found, with an idea for a new method for separating gas from oil. The method has been verified experimentally with favorable results.

  17. Bubble Departure Diameter and Bubble Release Frequency Measurement from TAMU Subcooled Flow Boiling Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jun Soo [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-12-01

    The bubble departure diameter and bubble release frequency were obtained through the analysis of TAMU subcooled flow boiling experimental data. The numerous images of bubbles at departure were analyzed for each experimental condition to achieve the reliable statistics of the measured bubble parameters. The results are provided in this report with simple discussion.

  18. Design and performance of main vacuum pumping system of SST-1 Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Ziauddin, E-mail: ziauddin@ipr.res.in; Pathan, Firozkhan; George, Siju; Dhanani, Kalpesh; Paravastu, Yuvakiran; Semwal, Pratibha; Pradhan, Subrata

    2014-01-15

    Highlights: •SST-1 Tokamak was successfully commissioned. •Vacuum vessel and cryostat were pumped down to 6.3 × 10{sup −7} mbar and 1.3 × 10{sup −5} mbar. •Leaks developed during baking were detected in-situ by RGA and confirmed later on. •Cryo-pumping effect was observed when LN2 thermal shields reached below 273 K. •Non-standard aluminum wire-seals have shown leak tightness < 1.0 × 10{sup −9} mbar l/s. -- Abstract: Steady-state Superconducting Tokamak (SST-1) was installed and it is commissioning for overall vacuum integrity, magnet systems functionality in terms of successful cool down to 4.5 K and charging up to 10 kA current was started from August 2012. Plasma operation of 100 kA current for more than 100 ms was also envisaged. It is comprised of vacuum vessel (VV) and cryostat (CST). Vacuum vessel, an ultra-high (UHV) vacuum chamber with net volume of 23 m{sup 3} was maintained at the base pressure of 6.3 × 10{sup −7} mbar for plasma confinement. Cryostat, a high-vacuum (HV) chamber with empty volume 39 m{sup 3} housing superconducting magnet system, bubble thermal shields and hydraulics for these circuits, maintained at 1.3 × 10{sup −5} mbar in order to provide suitable environment for these components. In order to achieve these ultimate vacuums, two numbers of turbo-molecular pumps (TMP) are installed in vacuum vessel while three numbers of turbo-molecular pumps are installed in cryostat. Initial pumping of both the chambers was carried out by using suitable Roots pumps. PXI based real time controlled system is used for remote operation of the complete pumping operation. In order to achieve UHV inside the vacuum vessel, it was baked at 150 °C for longer duration. Aluminum wire-seals were used for all non-circular demountable ports and a leak tightness < 1.0 × 10{sup −9} mbar l/s were achieved.

  19. A Joint Daily Operational Optimization Model for Wind Power and Pumped-storage Plant%风电-抽水蓄能联合日运行优化调度模型

    Institute of Scientific and Technical Information of China (English)

    胡泽春; 丁华杰; 孔涛

    2012-01-01

    基于日前负荷预测和风电出力预测,研究了风电一抽水蓄能联合日运行的优化方法,提出了电网消纳风电出力的新模式。以风电一抽水蓄能联合运行的效益最大化为目标,考虑抽水蓄能机组的启停限制和发电一抽水工况转换限制,以二次约束表征机组启停约束和抽水蓄能电站运行工况约束,建立了含全天96个时段的混合整数规划模型,并采用商业优化软件求解。基于实际抽水蓄能电站参数设计了算例系统。测试结果表明,抽水蓄能电站与风电场配合可大大降低风电出力随机性对电网运行的负面影响,经济和社会效益显著。%Based on the day-ahead forecast of system load and wind power output, this paper focuses on the optimization of the daily joint operation of wind power and pumped-storage plants, and a new mode of joint operation is proposed. A mixed-integer programming formulation is built to maximize the daily profit of the wind farm and the pumped-storage plant, where the time interval is 15 minutes and the constraints of unit startup-shutdown times are considered. The state change of units is taken into consideration by a quadratic constraint. The whole formulation is solved by commercial optimization software under MATLAB environment. A test case is developed based on the parameters of a practical pumped-storage plant. Simulation results indicate that the coordinated operation of wind farm and pumped-storage plant greatly reduces the negative impact of random wind power output on the power system operation and achieve significant economic and social benefits.

  20. Self Calibrating Flow Estimation in Waste Water Pumping Stations

    DEFF Research Database (Denmark)

    Kallesøe, Carsten Skovmose; Knudsen, Torben

    2016-01-01

    Knowledge about where waste water is flowing in waste water networks is essential to optimize the operation of the network pumping stations. However, installation of flow sensors is expensive and requires regular maintenance. This paper proposes an alternative approach where the pumps and the waste...... water pit are used for estimating both the inflow and the pump flow of the pumping station. Due to the nature of waste water, the waste water pumps are heavily affected by wear and tear. To compensate for the wear of the pumps, the pump parameters, used for the flow estimation, are automatically...

  1. Bubble nucleation in an explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.C.

    2008-01-01

    Explosive evaporation occurs when a thin layer of liquid reaches a temperature close to the critical temperature in a very short time. At these temperatures spontaneous nucleation takes place. The nucleated bubbles instantly coalesce forming a vapour film followed by rapid growth due to the pressure

  2. Single bubble sonoluminescence and stable cavitation

    Institute of Scientific and Technical Information of China (English)

    CHEN Qian; QIAN Menglu

    2004-01-01

    A single bubble trapped at an antinode of an acoustic standing wave field in water can emit 50ps-140ps light pulses, called "single bubble sonoluminescence" (SBSL). It arouses much interest in physical acoustics because of its highly non-linear characteristics, high concentration of energy, and stable cavitation behavior. In this paper, bubble stability, the dynamic behavior of bubbles, non-invasive measurement of driving acoustic pressure and Mie scattering method are introduced.

  3. Expansion of Bubbles in Inflationary Universe

    OpenAIRE

    Mohazzab, M.; Jabbari, M. M. Sheikh; Salehi, H.

    1995-01-01

    We show that particle production during the expansion of bubbles of true vacuum in the sea of false vacuum is possible and calculate the resulting rate. As a result the nucleated bubbles cannot expand due to the transfer of false vacuum energy to the created particles inside the bubbles. Therefore all the inflationary models dealing with the nucleation and expansion of the bubbles (including extended inflation) may not be viable.

  4. Expansion of bubbles in inflationary universe

    CERN Document Server

    Mohazzab, M

    1995-01-01

    We show that particle production during the expansion of bubbles of true vacuum in the sea of false vacuum is possible and calculate the resulting rate. As a result the nucleated bubbles cannot expand due to the transfer of false vacuum energy to the created particles inside the bubbles. Therefore all the inflationary models dealing with the nucleation and expansion of the bubbles (including extended inflation) may not be viable.

  5. Process and device for pumping electrolyte around several battery cells. Verfahren und Vorrichtung zum Umpumpen von Elektrolyt in mehrere Akkumulatorzellen

    Energy Technology Data Exchange (ETDEWEB)

    Poesch, G.

    1987-06-04

    In order to make pumping of electrolyte from a joint reservoir around electrically connected battery cells possible, according to the invention, the elecrolyte is pumped around in small portions alternately with a non-conducting liquid (= oil). A double diaphragm pump operating in push-pull has two suction pipes, where one suction pipe opens into the area of the acid and the other suction pipe opens into the area of the oil layer of the reservoir. The two outgoing pipes of the double diaphragm pump combine into the supply pipe, in which acid and oil can therefore be transported separately. As the oil wets the wall of the supply pipe better than the acid, acid bubbles are formed, which are surrounded by oil, and therefore cannot produce a conducting connection (= no danger of short-circuit). The acid/oil mixture from the supply pipe reaches the battery cells and separates out because of the different specific weights, so that the acid fills the battery cell from below and is topped by an oil layer above.

  6. Kinetics of conversion of air bubbles to air-hydrate crystals in antarctic ice

    CERN Document Server

    Price, P B

    1995-01-01

    The depth-dependence of bubble concentration at pressures above the transition to the air hydrate phase and the optical scattering length due to bubbles in deep ice at the South Pole are modeled using diffusion-growth data from the laboratory, taking into account the dependence of age and temperature on depth in the ice. The model fits the available data on bubbles in cores from Vostok and Byrd and on scattering length in deep ice at the South Pole. It explains why bubbles and air hydrate crystals co-exist in deep ice over a range of depths as great as 800 m and predicts that at depths below \\rm \\sim 1400 m the AMANDA neutrino observatory at the South Pole will operate unimpaired by light scattering from bubbles.

  7. Discrete particle modeling of granular temperature distribution in a bubbling fluidized bed

    Institute of Scientific and Technical Information of China (English)

    Yurong He; Tianyu Wang; Niels Deen; Martin van Sint Annaland; Hans Kuipers; Dongsheng Wen

    2012-01-01

    The discrete hard sphere particle model (DPM) is applied in this work to study numerically the distributions of particle and bubble granular temperatures in a bubbling fluidized bed.The dimensions of the bed and other parameters are set to correspond to those of Müller et al.(2008).Various drag models and operational parameters are investigated to find their influence on particle and bubble granular temperatures.Various inlet superficial gas velocities are used in this work to obtain their effect on flow characteristics.It is found that the superficial gas velocity has the most important effect on granular temperatures including bubble granular temperature,particle translational granular temperature and particle rotational granular temperature.The drag force model affects more seriously the large scale variables such as the bubble granular temperature.Restitution coefficient influences all granular temperatures to some degree.Simulation results are compared with experimental results by Müller et al.(2008) showing reasonable agreement.

  8. Experimental study on bubble size distributions in a direct-contact evaporator

    Directory of Open Access Journals (Sweden)

    Ribeiro Jr. C. P.

    2004-01-01

    Full Text Available Experimental bubble size distributions and bubble mean diameters were obtained by means of a photographic technique for a direct-contact evaporator operating in the quasi-steady-state regime. Four gas superficial velocities and three different spargers were analysed for the air-water system. In order to assure the statistical significance of the determined size distributions, a minimum number of 450 bubbles was analysed for each experimental condition. Some runs were also conducted with an aqueous solution of sucrose to study the solute effect on bubble size distribution. For the lowest gas superficial velocity considered, at which the homogeneous bubbling regime is observed, the size distribution was log-normal and depended on the orifice diameter in the sparger. As the gas superficial velocity was increased, the size distribution progressively acquired a bimodal shape, regardless of the sparger employed. The presence of sucrose in the continuous phase led to coalescence hindrance.

  9. DO-increasing effects of a microscopic bubble generating system in a fish farm.

    Science.gov (United States)

    Endo, Akira; Srithongouthai, Sarawut; Nashiki, Hisatsune; Teshiba, Ichiro; Iwasaki, Takaaki; Hama, Daigo; Tsutsumi, Hiroaki

    2008-01-01

    We have developed a "microscopic bubble generating system for the fish farm" and evaluated its ability to improve the quality of seawater and costs of it in marine cages of red sea bream (Pagrus major) in Kusuura Bay, Japan. Our results revealed that DO concentration of bubbling net pens increased and became significantly higher than the level outside the net pen (between 0.52 and 0.87 mg/L), and the whole water column was nearly saturated. Temperatures of the bubbling net pens decreased slightly between 0.08 and 0.12 degrees C in all the layers. Furthermore, micro-bubbles seemed to reach the deeper water due to the downward flow and diffusion. This study demonstrated that the microscopic bubble generating system developed in our research project could increase efficiently the dissolved oxygen concentration throughout all water layers of the fish farm. A capital and operation costs of the system is recoverable within a year.

  10. EXPERIMENTAL AND NUMERICAL INVESTIGATION OF BUBBLE AUGMENTED WATERJET PROPULSION

    Institute of Scientific and Technical Information of China (English)

    WU Xiongjun; CHOI Jin-Keun; SINGH Sowmitra; HSIAO Chao-Tsung; CHAHINE Georges L.

    2012-01-01

    This contribution presents experimental and numerical investigations of the concept jet propulsion augmentation using bubble injection.A half-3D (D-shaped cylindrical configuration to enable optimal visualizations) divergent-convergent nozzle was designed,built,and used for extensive experiments under different air injection conditions and thrust measurement schemes.The design,optimization,and analysis were conducted using numerical simulations.The more advanced model was based on a two-way coupling between an Eulerian description of the flow field and a Lagrangian tracking of the injected bubbles using our Surface Averaged Pressure (SAP) model.The numerical resultscompare very favorably with nozzle experiments and both experiments and simulations validation the thrust augmentation concept.For a properly designed nozzle and air injection system,air injection produces net thrust augmentation,which increases with the rate of bubble injection.Doubling of thrust was measured for a 50% air injection rate.This beneficial effect remains at 50% after account for liquid pump additional work to overcome increased pressure by air injection.

  11. Transverse pumped laser amplifier architecture

    Science.gov (United States)

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  12. Experience with Dry Running Vacuum Pumps in Helium Service

    Science.gov (United States)

    Arztmann, R.

    2008-03-01

    A process vacuum system for helium using dry running vacuum pumps only was shop tested and installed in a refrigeration plant to serve cavities operating at 2K for a cryogenic storage ring. The paper explains the joint development steps of Busch AG and Linde Kryotechnik AG to use dry running vacuum pumps for helium service at ambient temperature. A roots type booster pump followed by a non lube rotary screw pump provides very good performance in a helium vacuum pump system. Variable frequency drives on both pumps allow to adjust the pump characteristics to a wide range of operating parameters. Operation without friction of sealing elements in the compression space also of the screw pump promises extended maintenance intervals and virtually no wear on the rotors. The current plant operation at Max Plank Institute in Heidelberg, Germany Laboratory will provide additional experience for further applications.

  13. Radiation Damping at a Bubble Wall

    CERN Document Server

    Lee, J; Lee, C H; Jang, J; Lee, Jae-weon; Kim, Kyungsub; Lee, Chul H.; Jang, Ji-ho

    1999-01-01

    The first order phase transition proceeds via nucleation and growth of true vacuum bubbles. When charged particles collide with the bubble they could radiate electromagnetic wave. We show that, due to an energy loss of the particles by the radiation, the damping pressure acting on the bubble wall depends on the velocity of the wall even in a thermal equilibrium state.

  14. Bubble Formation in Silicon-Quartz Interface

    OpenAIRE

    Kakimoto, K.; EGUCHI, M.; Ozoe, H.

    1997-01-01

    Bubble formation at an interface between silicon melt and a quartz crucible was studied by thermodynamical calculation and visualization of bubble formation using X-ray radiography. A phase diagram of silicon-oxygen (Si-O) system is also calculated from the reported thermodynamical data. Critical temperature and radius of bubble formation at the interface was discussed.

  15. Bubble Size Distributions in Coastal Seas

    NARCIS (Netherlands)

    Leeuw, G. de; Cohen, L.H.

    1995-01-01

    Bubble size distributions have been measured with an optical system that is based on imaging of a small sample volume with a CCD camera system, and processing of the images to obtain the size of individual bubbles in the diameter range from 30 to lOOO^m. This bubble measuring system is deployed from

  16. Dynamic behavior of gas bubble in single bubble sonoluminescence - vibrator model

    Institute of Scientific and Technical Information of China (English)

    QIAN Menglu; CHENG Qian; GE Caoyan

    2002-01-01

    Single bubble sonoluminescence is a process of energy transformation from soundto light. Therefore the motion equations of near spherical vibration of a gas bubble in anincompressible and viscous liquid can be deduced by Lagrangian Equation with dissipationfunction when the bubble is considered as a vibrator surrounded by liquid. The analyticalsolutions in the bubble expanding, collapsing and rebounding stages can be obtained by solvingthese motion equations when some approximations are adopted. And the dynamic behaviorsof the bubble in these three stages are discussed.

  17. Bubble Radiation Detection: Current and Future Capability

    Energy Technology Data Exchange (ETDEWEB)

    AJ Peurrung; RA Craig

    1999-11-15

    Despite a number of noteworthy achievements in other fields, superheated droplet detectors (SDDs) and bubble chambers (BCs) have not been used for nuclear nonproliferation and arms control. This report examines these two radiation-detection technologies in detail and answers the question of how they can be or should be ''adapted'' for use in national security applications. These technologies involve closely related approaches to radiation detection in which an energetic charged particle deposits sufficient energy to initiate the process of bubble nucleation in a superheated fluid. These detectors offer complete gamma-ray insensitivity when used to detect neutrons. They also provide controllable neutron-energy thresholds and excellent position resolution. SDDs are extraordinarily simple and inexpensive. BCs offer the promise of very high efficiency ({approximately}75%). A notable drawback for both technologies is temperature sensitivity. As a result of this problem, the temperature must be controlled whenever high accuracy is required, or harsh environmental conditions are encountered. The primary findings of this work are listed and briefly summarized below: (1) SDDs are ready to function as electronics-free neutron detectors on demand for arms-control applications. The elimination of electronics at the weapon's location greatly eases the negotiability of radiation-detection technologies in general. (2) As a result of their high efficiency and sharp energy threshold, current BCs are almost ready for use in the development of a next-generation active assay system. Development of an instrument based on appropriately safe materials is warranted. (3) Both kinds of bubble detectors are ready for use whenever very high gamma-ray fields must be confronted. Spent fuel MPC and A is a good example where this need presents itself. (4) Both kinds of bubble detectors have the potential to function as low-cost replacements for conventional neutron

  18. In vivo evaluation of centrifugal blood pump for cardiopulmonary bypass-Spiral Pump.

    Science.gov (United States)

    da Silva, Cibele; da Silva, Bruno Utiyama; Leme, Juliana; Uebelhart, Beatriz; Dinkhuysen, Jarbas; Biscegli, José F; Andrade, Aron; Zavaglia, Cecília

    2013-11-01

    The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This rotor is supported by two ball bearings, attached to a stainless steel shaft fixed to the housing base. Worm gears provide axial motion to the blood column, and the rotational motion of the conically shaped impeller generates a centrifugal pumping effect, improving pump efficiency without increasing hemolysis. In vitro tests were performed to evaluate the SP's hydrodynamic performance, and in vivo experiments were performed to evaluate hemodynamic impact during usual CPB. A commercially available centrifugal blood pump was used as reference. In vivo experiments were conducted in six male pigs weighing between 60 and 90 kg, placed on CPB for 6 h each. Blood samples were collected just before CPB (T0) and after every hour of CPB (T1-T6) for hemolysis determination and laboratory tests (hematological and biochemical). Values of blood pressure, mean flow, pump rotational speed, and corporeal temperature were recorded. Also, ergonomic conditions were recorded: presence of noise, difficulty in removing air bubbles, trouble in installing the pump in the drive module (console), and difficulties in mounting the CPB circuit. Comparing the laboratory and hemolysis results for the SP with those of the reference pump, we can conclude that there is no significant difference between the two devices. In addition, reports made by medical staff and perfusionists described a close similarity between the two devices. During in vivo experiments, the SP maintained blood flow and pressure at physiological levels, consistent with those applied in cardiac surgery with CPB, without presenting any malfunction. Also, the SP needed lower rotational

  19. Time and Space Resolved Heat Transfer Measurements Under Nucleate Bubbles with Constant Heat Flux Boundary Conditions

    Science.gov (United States)

    Myers, Jerry G.; Hussey, Sam W.; Yee, Glenda F.; Kim, Jungho

    2003-01-01

    Investigations into single bubble pool boiling phenomena are often complicated by the difficulties in obtaining time and space resolved information in the bubble region. This usually occurs because the heaters and diagnostics used to measure heat transfer data are often on the order of, or larger than, the bubble characteristic length or region of influence. This has contributed to the development of many different and sometimes contradictory models of pool boiling phenomena and dominant heat transfer mechanisms. Recent investigations by Yaddanapyddi and Kim and Demiray and Kim have obtained time and space resolved heat transfer information at the bubble/heater interface under constant temperature conditions using a novel micro-heater array (10x10 array, each heater 100 microns on a side) that is semi-transparent and doubles as a measurement sensor. By using active feedback to maintain a state of constant temperature at the heater surface, they showed that the area of influence of bubbles generated in FC-72 was much smaller than predicted by standard models and that micro-conduction/micro-convection due to re-wetting dominated heat transfer effects. This study seeks to expand on the previous work by making time and space resolved measurements under bubbles nucleating on a micro-heater array operated under constant heat flux conditions. In the planned investigation, wall temperature measurements made under a single bubble nucleation site will be synchronized with high-speed video to allow analysis of the bubble energy removal from the wall.

  20. Some new insights of the characteristics of equatorial plasma bubbles obtained from Indian region

    Science.gov (United States)

    Narayanan, V. L.; Gurubaran, S.; Shiny, M. B. Berlin; Emperumal, K.; Patil, P. T.

    2017-04-01

    All-sky imaging observations of OI 630.0 nm airglow were carried out in campaign mode from Panhala (16.8°N, 74.1°E geographic; 11.1°N dip latitude), India, during January to March 2008. On 14 of 37 nights, equatorial plasma bubbles were observed. The drift speeds were observed to decrease with time in concurrence with the previous results. The tilts were mostly westward while on rare occasions the plasma bubbles tilted eastwards. The drifts were found to be relatively lesser on disturbed nights while the tilts appear to be marginally larger. The interdepletion distances (or bubble spacings) also showed a decreasing trend with time till midnight indicating that the bubbles approach each other with the passage of time. Such a behavior is not reported earlier and it seems to have important implications for understanding the time evolution of plasma bubbles. On occasions, the bubbles occurred in groups. An ionosonde operating over Indian dip equatorial site Tirunelveli (1.1°N dip latitude) was used to study the variations in the base height of the ionosphere during the plasma bubble observations. The ionosonde measurements indicate lack of significant pre-reversal enhancement (PRE) during geomagnetic quiet days in which the bubbles were observed.

  1. Elastic effects of dilute polymer solution on bubble generation in a microfluidic flow-focusing channel

    Science.gov (United States)

    Kim, Dong Young; Shim, Tae Soup; Kim, Ju Min

    2017-05-01

    Recently, two-phase flow in microfluidics has attracted much attention because of its importance in generating droplets or bubbles that can be used as building blocks for material synthesis and biological applications. However, there are many unresolved issues in understanding droplet and bubble generation processes, especially when complex fluids are involved. In this study, we investigated elastic effects on bubble generation processes in a flow-focusing geometry and the shapes of the produced bubbles flowing through a microchannel. We used dilute polymer solutions with nearly constant shear viscosities so that the shear-thinning effects on bubble generation could be precluded. We observed that a very small amount of polymer (poly(ethylene oxide) at O(10) ppm) significantly affects bubble generation. When the polymer was added to a Newtonian fluid, the fluctuation in bubble size increased notably, which was attributed to the chaotic flow dynamics in the flow-focusing region. In addition, it was demonstrated that the bubbles were thinner along the minor axis in the viscoelastic fluid than they were in the Newtonian fluid. We expect that the current results will contribute to understanding the dynamics of two-phase flow in microchannels and the design and operation of the microfluidic devices to generate microbubbles.

  2. 抽水蓄能电站与风电的联合优化运行建模及应用分析%Modeling and Application Analysis of Optimal Joint Operation of Pumped Storage Power Station and Wind Power

    Institute of Scientific and Technical Information of China (English)

    徐飞; 陈磊; 金和平; 刘振华

    2013-01-01

    With its excellent peak clipping and valley filling capability, the pumped storage power station can improve the accommodation capability of the wind power. Based on the actual data of West Inner Mongolia power grid and Hohhot pumped storage power station, the optimal joint operation of pumped storage power station and large-scale grid-connected wind power is simulated and investigated. By considering the intermittency and fluctuation of wind power, an optimization model for the joint operation is developed. The validity of the model is verified through simulation of the joint operation of Hohhot pumped storage power station and wind power integrated to West Inner Mongolia power grid based on the actual data of heating season and nonheating season. The simulation also shows the feasibility and benefit of the joint operation. During the heating season when part of the wind power is curtailed, the pumped storage power station shifts peak load and helps the power grid to accommodate more wind power. During the nonheating season with little wind power curtailment, the pumped storage power station is reserved for wind power and balances the fluctuation of wind power.%抽水蓄能电站具有优良的调峰填谷能力,能够有效提高电网消纳风电的能力.基于蒙西电网和呼和浩特抽水蓄能电站的实际数据,对抽水蓄能电站与大规模并网风电联合优化运行进行了模拟和研究.考虑风电的间歇性和波动性,建立了抽水蓄能电站与风电联合运行的优化模型.然后分别利用供热期和非供热期的系统数据,对蒙西电网中呼和浩特抽水蓄能电站与风电的联合运行进行了模拟,验证了模型的有效性,并说明了抽水蓄能电站与大规模并网风电联合运行的可行性以及带来的显著效益:供热期存在弃风时,抽水蓄能电站充分发挥调峰填谷的能力以减少弃风;非供热期弃风不明显时,抽水蓄能电站主要为风电提供备用,并平衡风电出力波动.

  3. The Hydraulic Ram (Or Impulse) Pump

    Science.gov (United States)

    Mills, Allan

    2014-01-01

    The hydraulic impulse pump utilizes a fraction of the momentum of a flowing stream to lift a small portion of that water to a higher level. There it may be accumulated in an elevated cistern to provide sufficient water for several families, for the pump works 24 h a day with no additional source of energy. The operation of the pump is described,…

  4. Droplets, Bubbles and Ultrasound Interactions

    NARCIS (Netherlands)

    Shpak, O.; Verweij, M.; Jong, de N.; Versluis, M.; Escoffre, J.M.; Bouakaz, A.

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to

  5. "Financial Bubbles" and Monetary Policy

    Science.gov (United States)

    Tikhonov, Yuriy A.; Pudovkina, Olga E.; Permjakova, Juliana V.

    2016-01-01

    The relevance of this research is caused by the need of strengthening a role of monetary regulators to prevent financial bubbles in the financial markets. The aim of the article is the analysis of a problem of crisis phenomena in the markets of financial assets owing to an inadequate growth of their cost, owing to subjective reasons. The leading…

  6. Explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.C.

    2007-01-01

    Explosive evaporation occurs when a thin layer of liquid reaches a very high temperature in a very short time. At these temperatures homogeneous nucleation takes place. The nucleated bubbles almost instantly coalesce forming a vapour film followed by rapid growth due to the pressure impulse and fina

  7. Giant Bubble Pinch-Off

    NARCIS (Netherlands)

    Bergmann, R.P.H.M.; van der Meer, Roger M.; Stijnman, Mark; Stijnman, M; Sandtke, M.; Prosperetti, Andrea; Lohse, Detlef

    2006-01-01

    Self-similarity has been the paradigmatic picture for the pinch-off of a drop. Here we will show through high-speed imaging and boundary integral simulations that the inverse problem, the pinch-off of an air bubble in water, is not self-similar in a strict sense: A disk is quickly pulled through a w

  8. Murray Strasberg and bubble acoustics

    NARCIS (Netherlands)

    Prosperetti, Andrea

    2014-01-01

    Murray Strasberg made seminal contributions to the nucleation and acoustics of bubbles. Half a century after publication, these papers still receive a sizable number of citations every year. The talk will review this work, comment on its impact, and put Strasberg's classical results in a modern

  9. Electrolysis Bubbles Make Waterflow Visible

    Science.gov (United States)

    Schultz, Donald F.

    1990-01-01

    Technique for visualization of three-dimensional flow uses tiny tracer bubbles of hydrogen and oxygen made by electrolysis of water. Strobe-light photography used to capture flow patterns, yielding permanent record that is measured to obtain velocities of particles. Used to measure simulated mixing turbulence in proposed gas-turbine combustor and also used in other water-table flow tests.

  10. Impurity bubbles in a BEC

    Science.gov (United States)

    Timmermans, Eddy; Blinova, Alina; Boshier, Malcolm

    2013-05-01

    Polarons (particles that interact with the self-consistent deformation of the host medium that contains them) self-localize when strongly coupled. Dilute Bose-Einstein condensates (BECs) doped with neutral distinguishable atoms (impurities) and armed with a Feshbach-tuned impurity-boson interaction provide a unique laboratory to study self-localized polarons. In nature, self-localized polarons come in two flavors that exhibit qualitatively different behavior: In lattice systems, the deformation is slight and the particle is accompanied by a cloud of collective excitations as in the case of the Landau-Pekar polarons of electrons in a dielectric lattice. In natural fluids and gases, the strongly coupled particle radically alters the medium, e.g. by expelling the host medium as in the case of the electron bubbles in superfluid helium. We show that BEC-impurities can self-localize in a bubble, as well as in a Landau-Pekar polaron state. The BEC-impurity system is fully characterized by only two dimensionless coupling constants. In the corresponding phase diagram the bubble and Landau-Pekar polaron limits correspond to large islands separated by a cross-over region. The same BEC-impurity species can be adiabatically Feshbach steered from the Landau-Pekar to the bubble regime. This work was funded by the Los Alamos LDRD program.

  11. The effects of bubble-bubble interactions on pressures and temperatures produced by bubbles collapsing near a rigid surface

    Science.gov (United States)

    Alahyari Beig, Shahaboddin; Johnsen, Eric

    2016-11-01

    Cavitation occurs in a wide range of hydraulic applications, and one of its most important consequences is structural damage to neighboring surfaces following repeated bubble collapse. A number of studies have been conducted to predict the pressures produced by the collapse of a single bubble. However, the collapse of multiple bubbles is known to lead to enhanced collapse pressures. In this study, we quantify the effects of bubble-bubble interactions on the bubble dynamics and pressures/temperatures produced by the collapse of a pair of bubbles near a rigid surface. For this purpose, we use an in-house, high-order accurate shock- and interface-capturing method to solve the 3D compressible Navier-Stokes equations for gas/liquid flows. The non-spherical bubble dynamics are investigated and the subsequent pressure and temperature fields are characterized based on the relevant parameters entering the problem: stand-off distance, geometrical configuation, collapse strength. We demonstrate that bubble-bubble interactions amplify/reduce pressures and temperatures produced at the collapse, and increase the non-sphericity of the bubbles and the collapse time, depending on the flow parameters.

  12. Operation Optimization of Constant-speed Circulating Water Pumps in a Thermal Power Plant under Full Conditions%火电机组定速循环水泵的全工况运行优化

    Institute of Scientific and Technical Information of China (English)

    刘吉臻; 王玮; 曾德良; 常太华; 柳玉

    2011-01-01

    为解决枚举法得出的定速循环水泵最优运行方式的局限性,通过分析汽轮机低压缸、冷却塔及凝汽器真空的全工况计算模型,提出了在环境温度相等的前提下进行循环水泵全工况运行优化,并对其流程进行了阐述,将排汽压力对汽轮机功率的修正曲线进行了全工况拟合,利用二分法求解机组各工况下循环水泵相邻运行方式的等效益点,进而获得等效益曲线,并采用二分法对某电厂的定速循环水泵进行了等效益曲线实例验证.结果表明:循环水泵优化运行后,平均可降低煤耗0.594g/(kw·h).%In order to overcome the limitation of optimized operation of constant-speed circulating water pumps obtained by enumeration method, the idea of optimizing the operation of circulating water pumps under full conditions was proposed on the premise of equal inlet temperature of cooling water, based on a- nalysis of full-condition calculation models for low-pressure cylinder, cooling tower and condenser vacuum. The specific optimization process is to fit the corrective curve between turbine power and exhaust pressure under full conditions, then to solve the equal efficiency points between adjacent operating modes of circu- lating water pumps by dichotomy method, and finally to acquire the equal efficiency curves. Verification results on the equal efficiency curves in a certain power plant show that an average of 0. 594 g/(kw .h) net coal consumption can be saved after the optimization of relevant circulating water pumps.

  13. Experimental study of the interaction between the spark-induced cavitation bubble and the air bubble

    Institute of Scientific and Technical Information of China (English)

    罗晶; 许唯临; 牛志攀; 罗书靖; 郑秋文

    2013-01-01

    Experiments are carried out by using high-speed photography to investigate the interaction between the spark-generated cavitation bubble and the air bubble in its surrounding fluid. Three problems are discussed in detail: the impact of the air bubble upon the development of the cavitation bubble, the evolution of the air bubble under the influence of the cavitation bubble, and the change of the fluid pressure during the development of a micro jet of the cavitation bubble. Based on the experimental results, under the condition of no air bubble present, the lifetime of the cavitation bubble from expansion to contraction increases with the increase of the maximum radius. On the other hand, when there is an air bubble present, different sized cavitation bubbles have similarity with one another generally in terms of the lifetime from expansion to contraction, which does not depend on the maximum radius. Also, with the presence of an air bubble, the lifetime of the smaller cavitation bubble is extended while that of the bigger ones reduced. Furthermore, it is shown in the experiment that the low pressure formed in the opposite direction to the cavitation bubble micro jet makes the air bubble in the low pressure area being stretched into a steplike shape.

  14. Lean-Burn Stationary Natural Gas Reciprocating Engine Operation with a Prototype Miniature Diode Side Pumped Passively Q-switched Laser Spark Plug

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, D.L.; Woodruff, S.D.; McMillian, M.H.; Richardson, S.W.; Gautam, Mridul

    2008-04-01

    To meet the ignition system needs of large bore lean burn stationary natural gas engines a laser diode side pumped passively Q-switched laser igniter was developed and used to ignite lean mixtures in a single cylinder research engine. The laser design was produced from previous work. The in-cylinder conditions and exhaust emissions produced by the miniaturized laser were compared to that produced by a laboratory scale commercial laser system used in prior engine testing. The miniaturized laser design as well as the combustion and emissions data for both laser systems was compared and discussed. It was determined that the two laser systems produced virtually identical combustion and emissions data.

  15. Shell correction energy for bubble nuclei

    CERN Document Server

    Yu, Y; Magierski, P; Bulgac, Aurel; Magierski, Piotr

    2000-01-01

    The positioning of a bubble inside a many fermion system does not affect the volume, surface or curvature terms in the liquid drop expansion of the total energy. Besides possible Coulomb effects, the only other contribution to the ground state energy of such a system arises from shell effects. We show that the potential energy surface is a rather shallow function of the displacement of the bubble from the center and in most cases the preferential position of a bubble is off center. Systems with bubbles are expected to have bands of extremely low lying collective states, corresponding to various bubble displacements.

  16. Robust acoustic wave manipulation of bubbly liquids

    Energy Technology Data Exchange (ETDEWEB)

    Gumerov, N. A., E-mail: gumerov@umiacs.umd.edu [Institute for Advanced Computer Studies, University of Maryland, College Park, Maryland 20742 (United States); Center for Micro- and Nanoscale Dynamics of Dispersed Systems, Bashkir State University, Ufa 450076 (Russian Federation); Akhatov, I. S. [Center for Design, Manufacturing and Materials, Skolkovo Institute of Science and Technology, Moscow 143026 (Russian Federation); Ohl, C.-D. [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 (Singapore); Center for Micro- and Nanoscale Dynamics of Dispersed Systems, Bashkir State University, Ufa 450076 (Russian Federation); Sametov, S. P. [Center for Micro- and Nanoscale Dynamics of Dispersed Systems, Bashkir State University, Ufa 450076 (Russian Federation); Khazimullin, M. V. [Center for Micro- and Nanoscale Dynamics of Dispersed Systems, Bashkir State University, Ufa 450076 (Russian Federation); Institute of Molecule and Crystal Physics, Ufa Research Center of Russian Academy of Sciences, Ufa 450054 (Russian Federation); Gonzalez-Avila, S. R. [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 (Singapore)

    2016-03-28

    Experiments with water–air bubbly liquids when exposed to acoustic fields of frequency ∼100 kHz and intensity below the cavitation threshold demonstrate that bubbles ∼30 μm in diameter can be “pushed” away from acoustic sources by acoustic radiation independently from the direction of gravity. This manifests formation and propagation of acoustically induced transparency waves (waves of the bubble volume fraction). In fact, this is a collective effect of bubbles, which can be described by a mathematical model of bubble self-organization in acoustic fields that matches well with our experiments.

  17. Lidar signature from bubbles in the sea.

    Science.gov (United States)

    Churnside, James H

    2010-04-12

    The lidar signature from a collection of bubbles is proportional to the volume backscatter coefficient at a scattering angle of 180 degrees . This quantity, calculated using a combination of geometric optics and diffraction, is proportional to the void fraction of the bubbles in the water for any bubble size distribution. The constant of proportionality is 233 m(-1) sr(-1)for clean bubbles, slightly less for bubbles coated with a thin layer of organic material, and as large as 1445 m(-1) sr(-1) for a thick coating of protein.

  18. Supercoiling induces denaturation bubbles in circular DNA.

    Science.gov (United States)

    Jeon, Jae-Hyung; Adamcik, Jozef; Dietler, Giovanni; Metzler, Ralf

    2010-11-12

    We present a theoretical framework for the thermodynamic properties of supercoiling-induced denaturation bubbles in circular double-stranded DNA molecules. We explore how DNA supercoiling, ambient salt concentration, and sequence heterogeneity impact on the bubble occurrence. An analytical derivation of the probability distribution to find multiple bubbles is derived and the relevance for supercoiled DNA discussed. We show that in vivo sustained DNA bubbles are likely to occur due to partial twist release in regions rich in weaker AT base pairs. Single DNA plasmid imaging experiments clearly demonstrate the existence of bubbles in free solution.

  19. Bubble Universe Dynamics After Free Passage

    CERN Document Server

    Ahlqvist, Pontus; Greene, Brian

    2013-01-01

    We consider bubble collisions in single scalar field theories with multiple vacua. Recent work has argued that at sufficiently high impact velocities, collisions between such bubble vacua are governed by 'free passage' dynamics in which field interactions can be ignored during the collision, providing a systematic process for populating local minima without quantum nucleation. We focus on the time period that follows the bubble collision and provide evidence that, for certain potentials, interactions can drive significant deviations from the free-passage bubble profile, thwarting the production of bubbles with different field values.

  20. Self Calibrating Flow Estimation in Waste Water Pumping Stations

    DEFF Research Database (Denmark)

    Kallesøe, Carsten Skovmose; Knudsen, Torben

    2016-01-01

    Knowledge about where waste water is flowing in waste water networks is essential to optimize the operation of the network pumping stations. However, installation of flow sensors is expensive and requires regular maintenance. This paper proposes an alternative approach where the pumps and the waste...... water pit are used for estimating both the inflow and the pump flow of the pumping station. Due to the nature of waste water, the waste water pumps are heavily affected by wear and tear. To compensate for the wear of the pumps, the pump parameters, used for the flow estimation, are automatically...... calibrated. This calibration is done based on data batches stored at each pump cycle, hence makes the approach a self calibrating system. The approach is tested on a pumping station operating in a real waste water network....