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Sample records for pump flexible suction

  1. Cavitation simulation and NPSH prediction of a double suction centrifugal pump

    International Nuclear Information System (INIS)

    Li, P; Huang, Y F; Li, J

    2012-01-01

    This paper illustrates the flow field numerical analysis of the double-suction centrifugal pump. For the study of the cavitation flow inside the double-suction centrifugal pump, the professional pump/motor simulation software PumpLinx and its Full Cavitation Model has been employed. According to the PumpLinx calculation result and the Cavitation damage index, the cavitation position, level and the cavitation characteristics of the double-suction centrifugal pump has been predicted. For the further objective, the simulation of the flow field in the double-suction centrifugal pump under different inlet conditions has been carried out. By the result analysis, NPSHr has been predicted; the reliability of the results has been verified by comparing with the experimental data. At the same time, this practice can provide guidance for the optimal design of double-suction pump.

  2. Numerical simulation and analysis of cavitation flows in a double suction centrifugal pump

    International Nuclear Information System (INIS)

    Meng, G; Tan, L; Cao, S L; Jian, W; Liu, W W; Jiang, D J

    2015-01-01

    Cavitation is an unsteady phenomenon, which is nearly inevitable in pumps. It would degrade the pump performance, generate vibrations and noises, and even erode pump flow passage components. The double suction centrifugal pump at design flow rate and large flow rate is numerically simulated using the k-ω turbulence model and the mass transport cavitation model. As a result, the calculated variation of pump head with pump inlet pressure agreed well with the experimental data. The results demonstrate that the numerical model and method can accurately predict the cavitation flows in a double suction centrifugal pump. The cavitation characteristics are analysed in great details. In addition, based on the calculation results, the reason that the plunge of pump head curve is revealed. It is found that the steep fall of pump head happens when the cavity reaches the blade to blade throat and the micro-vortex group appears at the back of the blade suction side. At the same time, this practice can provide guidance for the optimal design of double suction pumps

  3. Vortex cavitation and oscillation in a double-suction volute pump

    International Nuclear Information System (INIS)

    Sato, T; Nagahara, T; Tanaka, K; Fuchiwaki, M; Shimizu, F

    2010-01-01

    In recent years, Computational Fluid Dynamics (CFD) codes have been utilized actively in the early part of the product development cycle. Numerical analysis models have also been developed rapidly and have added cavitation flow analysis functions peculiar to hydraulic machines, in which the flow analysis has been developed remarkably with high-precision and high-reliability. On the other hand, it is well known that three kinds of cavitation, such as vortex cavitation, reverse flow cavitation and cloud cavitation appear in a double-suction volute pump. We have much interest in a relationship among the cavitating flows, pump oscillation and noise. In this study, full 3D numerical simulations have been performed using a commercial code inside the pump from the inlet of suction duct to the outlet of delivery duct. The numerical model is based on a combination of multiphase flow equations with the truncated version of the Rayleigh-Plesset model predicting the complicated growth and collapse process of cavity bubbles. This study highlights especially the mechanism of vortex cavitation occurrence from the end of the suction duct in the pump and pump oscillation which causes cavitation noise from the pump. The experimental investigations have also been performed on the cavitating flow with flow visualization to evaluate the numerical results.

  4. 21 CFR 878.4780 - Powered suction pump.

    Science.gov (United States)

    2010-04-01

    ...) Identification. A powered suction pump is a portable, AC-powered or compressed air-powered device intended to be used to remove infectious materials from wounds or fluids from a patient's airway or respiratory support system. The device may be used during surgery in the operating room or at the patient's bedside...

  5. Experimental Investigation of the Motion and Shape of Flexible Objects near a Pump Inlet

    DEFF Research Database (Denmark)

    Jensen, Anna Lyhne; Abou Ackl, Raja; Gerlach, Stefan

    Previous investigations of clogging effects in waste water pumps have focused on the impact of pumping contaminated water on the pump performance, as well as the influence of the operating point on the location of clogged material in the pump and in the pumping system. The present work aims...... to characterise the dynamics of flexible material entering a rotating impeller. Experiments are carried out in a wet pit located in the Department of Fluid System Dynamics in TU Berlin. The wet pit is modified with an acrylic plate placed at the bottom of the pit, enabling visual access to the suction side...

  6. Review of pump suction reducer selection: Eccentric or concentric reducers

    OpenAIRE

    Mahaffey, R M; van Vuuren, S J

    2014-01-01

    Eccentric reducers are traditionally recommended for the pump suction reducer fitting to allow for transportation of air through the fitting to the pump. The ability of a concentric reducer to provide an improved approach flow to the pump while still allowing air to be transported through the fitting is investigated. Computational fluid dynamics (CFD) were utilised to analyse six concentric and six eccentric reducer geometries at four different inlet velocities to determine the flow velocity ...

  7. 85,000-GPM, single-stage, single-suction LMFBR intermediate centrifugal pump

    International Nuclear Information System (INIS)

    Fair, C.E.; Cook, M.E.; Huber, K.A.; Rohde, R.

    1983-01-01

    The mechanical and hydraulic design features of the 85,000-gpm, single-stage, single-suction pump test article, which is designed to circulate liquid-sodium coolant in the intermediate heat-transport system of a Large-Scale Liquid Metal Fast Breeder Reactor (LS-LMFBR), are described. The design and analytical considerations used to satisfy the pump performance and operability requirements are presented. The validation of pump hydraulic performance using a hydraulic scale-model pump is discussed, as is the featute test for the mechanical-shaft seal system

  8. Suppression of secondary flows in a double suction centrifugal pump with different loading distributions

    International Nuclear Information System (INIS)

    Leng, H F; Wang, F J; Zhang, Z C; Yao, Z F; Zhou, P J

    2013-01-01

    Secondary flow is one of the main reasons for low efficiency in double suction centrifugal pump. In a 3-D inverse design method, the pump blade could be designed by a specified loading distribution to control the flow field in pump. In order to study the influence of loading distribution on secondary flow of a double suction centrifugal pump, the external characteristics and the internal flow field of the pump with three kinds of loading distributions are analysed by using CFD approach. According to the simulation results, it is found that the form of fore-loading distribution at shroud and aft-loading distribution at hub could improve the optimal efficiency and broaden the high efficiency area of the pump. Furthermore, the secondary flow in impeller exit region and volute could be significantly suppressed if the slope of loading distribution curve of shroud is set to be −0.7

  9. Suppression of the secondary flow in a suction channel of a large centrifugal pump

    International Nuclear Information System (INIS)

    Torii, D; Nagahara, T; Okihara, T

    2013-01-01

    The suction channel configuration of a large centrifugal pump with a 90-degree bend was studied in detail to suppress the secondary flow at the impeller inlet for improving suction performance. Design of experiments (DOE) and computational fluid dynamics (CFD) were used to evaluate the sensitivity of several primary design parameters of the suction channel. A DOE is a powerful tool to clarify the sensitivity of objective functions to design parameters with a minimum of trials. An L9 orthogonal array was adopted in this study and nine suction channels were designed, through which the flow was predicted by steady state calculation. The results indicate that a smaller bend radius with a longer straight nozzle, distributed between the bend and the impeller, suppresses the secondary flow at the impeller inlet. An optimum ratio of the cross sectional areas at the bend inlet and outlet was also confirmed in relationship to the contraction rate of the downstream straight nozzle. These findings were obtained by CFD and verified by experiments. The results will aid the design of large centrifugal pumps with better suction performance and higher reliability

  10. Reduction of the suction pressure of a liquid ring vacuum pump with a supersonic gas ejector

    Directory of Open Access Journals (Sweden)

    Olšiak Róbert

    2018-01-01

    Full Text Available A supersonic gas ejector in conjunction with a liquid ring vacuum pump is used for creating and maintaining vacuum in a chamber for technological purposes. In this paper the authors submit an overview about the problematics of suction pressure reduction with a supersonic gas ejector used as a pre-stage of a liquid ring vacuum pump. This system has also the function of a cavitation protection due to the higher pressure present at the suction throat of the vacuum pump. A part of this paper is devoted to the governing equations used at the definition of the flow through an ejector. The experimental studies are then carried out in or own laboratory for verification purposes.

  11. Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

    International Nuclear Information System (INIS)

    Zou, Zhichao; Wang, Fujun; Yao, Zhifeng; Tao, Ran; Xiao, Ruofu; Li, Huaicheng

    2016-01-01

    Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t_0) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t_0, the radial force is small (approaching zero). At 0.4–1.4t_0, the radial force increases rapidly. After 1.4t_0, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research provides a scientific

  12. Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Zhichao [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Wang, Fujun, E-mail: wangfj@cau.edu.cn [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Yao, Zhifeng [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Tao, Ran [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Xiao, Ruofu [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Li, Huaicheng [Shanghai Liancheng (Group) Co., Ltd., Shanghai 201812 (China)

    2016-12-15

    Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t{sub 0}) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t{sub 0}, the radial force is small (approaching zero). At 0.4–1.4t{sub 0}, the radial force increases rapidly. After 1.4t{sub 0}, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research

  13. Alignment and operability analysis of a vertical sodium pump

    International Nuclear Information System (INIS)

    Gupta, V.K.; Fair, C.E.

    1981-01-01

    With the objective of identifying important alignment features of pumps such as FFTF, HALLAM, EBR II, PNC, PHENIX, and CRBR, alignment of the vertical sodium pump for the Clinch River Breeder Reactor Plant (CRBRP) is investigated. The CRBRP pump includes a flexibly coupled pump shaft and motor shaft, two oil-film tilting-pad hydrodynamic radial bearings in the motor plus a vertical thrust bearing, and two sodium hydrostatic bearings straddling the double-suction centrifugal impeller in the pump

  14. Impedance of flexible suction caissons

    DEFF Research Database (Denmark)

    Liingaard, Morten; Andersen, Lars; Ibsen, Lars Bo

    2007-01-01

    The dynamic response of offshore wind turbines is affected by the properties of the foundation and the subsoil. The aim of this paper is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigations include evaluation of the vertical and cou...

  15. Time management and nectar flow: flower handling and suction feeding in long-proboscid flies (Nemestrinidae: Prosoeca)

    Science.gov (United States)

    Karolyi, Florian; Morawetz, Linde; Colville, Jonathan F.; Handschuh, Stephan; Metscher, Brian D.; Krenn, Harald W.

    2013-11-01

    A well-developed suction pump in the head represents an important adaptation for nectar-feeding insects, such as Hymenoptera, Lepidoptera and Diptera. This pumping organ creates a pressure gradient along the proboscis, which is responsible for nectar uptake. The extremely elongated proboscis of the genus Prosoeca (Nemestrinidae) evolved as an adaptation to feeding from long, tubular flowers. According to the functional constraint hypothesis, nectar uptake through a disproportionately elongated, straw-like proboscis increases flower handling time and consequently lowers the energy intake rate. Due to the conspicuous length variation of the proboscis of Prosoeca, individuals with longer proboscides are hypothesised to have longer handling times. To test this hypothesis, we used field video analyses of flower-visiting behaviour, detailed examinations of the suction pump morphology and correlations of proboscis length with body length and suction pump dimensions. Using a biomechanical framework described for nectar-feeding Lepidoptera in relation to proboscis length and suction pump musculature, we describe and contrast the system in long-proboscid flies. Flies with longer proboscides spent significantly more time drinking from flowers. In addition, proboscis length and body length showed a positive allometric relationship. Furthermore, adaptations of the suction pump included an allometric relationship between proboscis length and suction pump muscle volume and a combination of two pumping organs. Overall, the study gives detailed insight into the adaptations required for long-proboscid nectar feeding, and comparisons with other nectar-sucking insects allow further considerations of the evolution of the suction pump in insects with sucking mouthparts.

  16. AUTOMATIC CONTROL SYSTEM OF THE DIFFERENCE BETWEEN DISCHARGE AND SUCTION PRESSURES OF THE HEAT PUMP STATION COMPRESSOR

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2009-04-01

    Full Text Available Possibility of realization is shown and the control system of a difference of pressure between an exit and an input of the compressor of the heat pump on carbon dioxide working at variable thermal load, and discharge and suction pressures by means of two control valves connected in series is developed. On an example a flow coefficient calculation procedure of control valves is shown.

  17. Alignment analysis of a vertical sodium pump

    International Nuclear Information System (INIS)

    Gupta, V.K.; Fair, C.E.

    1981-01-01

    With the objective of identifying important alignment features of pumps such as FFTF, HALLAM, EBR II, PNC, PHENIX, and CRBR, alignment of the vertical sodium pump for the Clinch River Breeder Reactor Plant (CRBRP) is investigated. The CRBRP pump includes a flexibly coupled pump shaft and motor shaft, two oil-film tilting-pad hydrodynamic radial bearings in the motor plus a vertical thrust bearing, and two sodium hydrostatic bearings straddling the double-suction centrifugal impeller in the pump. The assembled CRBRP prototype pump shows smooth predictable vibration behavior experienced during water test. An ealier swing check of the pump shaft about the motor shaft hub demonstrated that the pump is relatively insensitive to manufacturing and assembly tolerances, a consequence of close dimensional control and unique alignment features. (orig./GL)

  18. Comparative study of the characteristics of some suction devices for gas sampling applications

    International Nuclear Information System (INIS)

    Donguy, R.; Drouet, J.

    1959-06-01

    Gas sampling (used to determine the characteristics of dusts or aerosols contained in a gas) needs a suction device. In order to select the right device and the right conditions of use, the characteristics and performances of various suction devices (helicoidal and centrifugal aspirators, air pumps, volumetric pumps) have been experimentally measured: flow rate, head loss, sampling volume and duration, aerosol and dust concentration, gas density, nature of the gas, suction circuit configuration, etc

  19. Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Hu Bing-shan

    2010-02-01

    Full Text Available Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

  20. Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Hu Bing-Shan

    2009-09-01

    Full Text Available Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

  1. Pumps and pump facilities. 2. ed.

    International Nuclear Information System (INIS)

    Bohl, W.; Bauerfeind, H.; Gutmann, G.; Leuschner, G.; Matthias, H.B.; Mengele, R.; Neumaier, R.; Vetter, G.; Wagner, W.

    1981-01-01

    This book deals with the common fundamental aspects of liquid pumps and gives an exemplary choice of the most important kinds of pumps. The scientific matter is dealt with by means of practical mathematical examples among other ways of presenting the matter. Survey of contents: Division on main operational data of pumps - pipe characteristics - pump characteristics - suction behaviour of the pumps - projecting and operation of rotary pumps - boiler feed pumps - reactor feed pumps - oscillating positive-displacement pumps - eccentric spiral pumps. (orig./GL) [de

  2. Demand flexibility from residential heat pump

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    Demand response (DR) is considered as a potentially effective tool to compensate generation intermittency imposed by renewable sources. Further, DR can instigate to offer optimum asset utilization and to avoid or delay the need for new infrastructure investment. Being a sizable load together...... with high thermal time constant, heat pumps (HP) can offer a great deal of flexibility in the future intelligent grids especially to compensate fluctuating generation. However, the HP flexibility is highly dependent on thermal demand profile, namely hot water and space heating demand. This paper proposes...... price based scheduling followed by a demand dispatch based central control and a local voltage based adaptive control, to realize HP demand flexibility. Two-step control architecture, namely local primary control encompassed by the central coordinative control, is proposed to implement...

  3. Effects of radial diffuser hydraulic design on a double-suction centrifugal pump

    Science.gov (United States)

    Hou, H. C.; Zhang, Y. X.; Xu, C.; Zhang, J. Y.; Li, Z. L.

    2016-05-01

    In order to study effects of radial diffuser on hydraulic performance of crude oil pump, the steady CFD numerical method is applied and one large double-suction oil pump running in long-distance pipeline is considered. The research focuses on analysing the influence of its diffuser vane profile on hydraulic performance of oil pump. The four different types of cylindrical vane have been designed by in-house codes mainly including double arcs (DA), triple arcs (TA), equiangular spiral line (ES) and linear variable angle spiral line (LVS). During design process diffuser vane angles at inlet and outlet are tentatively given within a certain range and then the wrapping angle of the four types of diffuser vanes can be calculated automatically. Under the given inlet and outlet angles, the linear variable angle spiral line profile has the biggest wrapping angle and profile length which is good to delay channel diffusion but bring more friction hydraulic loss. Finally the vane camber line is thickened at the certain uniform thickness distribution and the 3D diffuser models are generated. The whole flow passage of oil pump with different types of diffusers under various flow rate conditions are numerically simulated based on RNG k-ɛ turbulent model and SIMPLEC algorithm. The numerical results show that different types of diffusers can bring about great difference on the hydraulic performance of oil pump, of which the ES profile diffuser with its proper setting angle shows the best hydraulic performance and its inner flow field is improved obviously. Compared with the head data from model sample, all designed diffusers can make a certain improvement on head characteristic. At the large flow rate conditions the hydraulic efficiency increases obviously and the best efficiency point shift to the large flow rate range. The ES profile diffuser embodies the better advantages on pump performance which can be explained theoretically that the diffuser actually acts as a diffusion

  4. Teknik ved abortus provocatus, vabrasio og vakuumekstraktion. Klinisk afprøvning af Ambu Twin Pump 1000

    DEFF Research Database (Denmark)

    Krebs, L; Ingemanssen, Jens Lindgren; Jaszczak, P P

    1994-01-01

    Ambu Twin Pump 1000 is a suction pump designed for pharyngeal and tracheal suction in emergency situations. The pump can be operated by foot or by hand. The object of this test was to evaluate the applicability of the pump in performing legal abortion (before 13th. week), suction curettage...... and has sufficient suction capacity for the mentioned purposes. For induced abortion the pump was provided with a 200 ml reservoir for cleaning purposes....

  5. Modulation method of scroll compressor based on suction gas bypass

    International Nuclear Information System (INIS)

    Wang Baolong; Han Linjun; Shi Wenxing; Li Xianting

    2012-01-01

    The air conditioners and heat pumps tend to work in much mild environments and part load situations rather than provide the rated full capacity under severe rated testing conditions. Both the capacity and inner compression ratio of the compressor should be regulated according to the working condition for higher energy efficiency and occupants’ comfort. A potential modulating technology of the scroll compressor, suction gas bypass, is investigated in this paper. The principle and operation method are illuminated and the adaptability is validated by experiments and simulations. As a conclusion, an appropriate suction gas bypass can reduce the inner compression loss of the scroll compressor under over compression conditions, enhance the system COP and also largely decrease the heating/cooling capacity of the refrigeration/heat pump system. - Highlights: ► Suction gas bypass (SGB) is an effective regulating method of scroll compressor. ► SGB reduces the inner compression loss under over compression conditions. ► SGB largely decreases the heating/cooling capacity of the refrigeration system.

  6. Numerical Simulation of Tubular Pumping Systems with Different Regulation Methods

    Science.gov (United States)

    Zhu, Honggeng; Zhang, Rentian; Deng, Dongsheng; Feng, Xusong; Yao, Linbi

    2010-06-01

    Since the flow in tubular pumping systems is basically along axial direction and passes symmetrically through the impeller, most satisfying the basic hypotheses in the design of impeller and having higher pumping system efficiency in comparison with vertical pumping system, they are being widely applied to low-head pumping engineering. In a pumping station, the fluctuation of water levels in the sump and discharge pool is most common and at most time the pumping system runs under off-design conditions. Hence, the operation of pump has to be flexibly regulated to meet the needs of flow rates, and the selection of regulation method is as important as that of pump to reduce operation cost and achieve economic operation. In this paper, the three dimensional time-averaged Navier-Stokes equations are closed by RNG κ-ɛ turbulent model, and two tubular pumping systems with different regulation methods, equipped with the same pump model but with different designed system structures, are numerically simulated respectively to predict the pumping system performances and analyze the influence of regulation device and help designers make final decision in the selection of design schemes. The computed results indicate that the pumping system with blade-adjusting device needs longer suction box, and the increased hydraulic loss will lower the pumping system efficiency in the order of 1.5%. The pumping system with permanent magnet motor, by means of variable speed regulation, obtains higher system efficiency partly for shorter suction box and partly for different structure design. Nowadays, the varied speed regulation is realized by varied frequency device, the energy consumption of which is about 3˜4% of output power of the motor. Hence, when the efficiency of variable frequency device is considered, the total pumping system efficiency will probably be lower.

  7. Minimizing unbalance response of the CRBRP sodium pumps

    International Nuclear Information System (INIS)

    Gupta, V.K.; Marrujo, F.G.

    1979-04-01

    The unbalance response characteristics of the vertical pumps for the Clinch River Breeder Reactor Plant are investigated. Finite-element shell and beam models representative of the pump-motor structure including the rotating assembly are developed to assess structural stiffnesses of dominant joints as well as the foundation support stiffness so as to exclude the danger of resonant excitation during normal operation. Less than four mils peak-to-peak vibration amplitude at the pump tank discharge nozzle results from just 10% frequency separation between the first rocking mode and the maximum operating speed of 1116 RPM, based on 0.5% modal damping ratio and balance quality grade of ISO/ANSI G2.5 for the rotating components: motor rotor, pump shaft, Bendix diaphragm-type flexible coupling, and centrigual double-suction impeller. Several design options are explored for raising shaft critical speed beyond 125% of maximum operating speed

  8. Development of model pump for establishing hydraulic design of primary sodium pumps in PFBR

    International Nuclear Information System (INIS)

    Chougule, R.J.; Sahasrabudhe, H.G.; Rao, A.S.L.K.; Balchander, K.; Kale, R.D.

    1994-01-01

    Indira Gandhi Centre for Atomic Research, Kalpakkam indicated requirement of indigenous development of primary sodium pump, handling liquid sodium as coolant in Fast Breeder Reactor. The primary sodium pump concept selected in its preliminary design is a vertical, single stage, with single suction impeller, suction facing downwards. The pump is having diffuser, discharge casing and discharge collector. The 1/3 rd size model pump is developed to establish the hydraulic performance of the prototype primary sodium pump. The main objectives were to verify the hydraulic design to operate on low net positive suction head available (NPSHA), no evidence of visible cavitation at available NPSHA, the pump should be designed with a diffuser etc. The model pump PSP 250/40 was designed and successfully developed by Research and Development Division of M/s Kirloskar Brothers Ltd., Kirloskarvadi. The performance testing using model pump was successfully carried out on a closed circuit test rig. The performance of a model pump at three different speeds 1900 rpm, 1456 rpm and 975 rpm was established. The values of hydraulic axial thrust with and without balancing holes on impeller at 1900 rpm was measured. Visual cavitation study at 1900 rpm was carried out to establish the NPSH at bubble free operation of the pump. The tested performance of the model pump is converted to the full scale prototype pump. The predicted performance of prototype pump at 700 rpm was found to be meeting fully with the expected duties. (author). 6 figs., 3 tabs

  9. Experiment data of 200% recirculation pump discharge line break integral test run 961 with HPCS failure at ROSA-III and comparison with results of suction line break tests

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro; Tasaka, Kanji; Nakamura, Hideo; Anoda, Yoshinari; Kumamaru, Hiroshige; Murata, Hideo; Yonomoto, Taisuke; Shiba, Masayoshi

    1984-03-01

    This report presents the experimental data of RUN 961, a 200% double-ended break test at the recirculation pump discharge line in the ROSA-III test facility. The ROSA-III test facility is a volumetrically scaled (1/424) system of the BWR/6. The facility has the electrically heated core, the break simulator and the scaled ECCS (Emergency Core Cooling System). The MSIV (Main Steam Isolation Valve) closure and the ECCS actuation were tripped by the liquid level in the upper downcomer. The PCT (Peak Cladding Temperature) was 894 K, which was 107 K higher than a 200% pump suction line break test (RUN 926) due to the smaller depressurization rate. The effect of break location on transient LOCA phenomena was clarified by comparing the discharge and suction break tests. The whole core was quenched 71 s after LPCI actuation and the effectiveness of ECCS has been confirmed. (author)

  10. A Numerical Study on the Improvement of Suction Performance and Hydraulic Efficiency for a Mixed-Flow Pump Impeller

    Directory of Open Access Journals (Sweden)

    Sung Kim

    2014-01-01

    Full Text Available This paper describes a numerical study on the improvement of suction performance and hydraulic efficiency of a mixed-flow pump by impellers. The design of these impellers was optimized using a commercial CFD (computational fluid dynamics code and DOE (design of experiments. The design variables of meridional plane and vane plane development were defined for impeller design. In DOE, variables of inlet part were selected as main design variables in meridional plane, and incidence angle was selected in vane plane development. The verification of the experiment sets that were generated by 2k factorial was done by numerical analysis. The objective functions were defined as the NPSHre (net positive suction head required, total efficiency, and total head of the impellers. The importance of the geometric design variables was analyzed using 2k factorial designs. The interaction between the NPSHre and total efficiency, according to the meridional plane and incidence angle, was discussed by analyzing the 2k factorial design results. The performance of optimally designed model was verified by experiments and numerical analysis and the reliability of the model was retained by comparison of numerical analysis and comparative analysis with the reference model.

  11. Final Report: Summary of Findings and Recommendations for Suction Devices for Management of Prehospital Combat Casualty Care Injuries

    Science.gov (United States)

    2017-11-13

    Airway Final Report: Summary of Findings and Recommendations for Suction Devices for Management of Prehospital Combat Casualty Care Injuries...Consumer Style Comparison Table of Suction Pump Devices ............................. 103 Appendix H – Web Links for Images for Consumer- Style ...0022 pg. 6 Executive Summary Suction is a critical component of airway management , which is the second leading cause of preventable

  12. Feeding kinematics, suction, and hydraulic jetting performance of harbor seals (Phoca vitulina.

    Directory of Open Access Journals (Sweden)

    Christopher D Marshall

    Full Text Available The feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (Phoca vitulina were characterized during controlled feeding trials. Feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. Subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. The mean feeding cycle duration for suction-feeding events was significantly shorter (0.15±0.09 s; P<0.01 than biting feeding events (0.18±0.08 s. Subjects feeding in-water used both a suction and a biting feeding mode. Suction was the favored feeding mode (84% of all feeding events compared to biting, but biting comprised 16% of feeding events. In addition, seals occasionally alternated suction with hydraulic jetting, or used hydraulic jetting independently, to remove fish from the apparatus. Suction and biting feeding modes were kinematically distinct regardless of feeding location (in-water vs. on-land. Suction was characterized by a significantly smaller gape (1.3±0.23 cm; P<0.001 and gape angle (12.9±2.02°, pursing of the rostral lips to form a circular aperture, and pursing of the lateral lips to occlude lateral gape. Biting was characterized by a large gape (3.63±0.21 cm and gape angle (28.8±1.80°; P<0.001 and lip curling to expose teeth. The maximum subambient pressure recorded was 48.8 kPa. In addition, harbor seals were able to jet water at food items using suprambient pressure, also known as hydraulic jetting. The maximum hydraulic jetting force recorded was 53.9 kPa. Suction and hydraulic jetting where employed 90.5% and 9.5%, respectively, during underwater feeding events. Harbor seals displayed a wide repertoire of behaviorally flexible feeding strategies to ingest fish from the feeding apparatus. Such flexibility of feeding strategies and biomechanics likely forms the basis of their

  13. Annual technical progress report inducer pump program government fiscal year 1976 and 1976T

    International Nuclear Information System (INIS)

    1976-01-01

    The Inducer Pump Program was initiated to demonstrate the applicability and advantages of an inducer pump to the LMFBR. The inducer is a pump blading which is specifically tailored to provide excellent suction performance. Operating suction specific speeds two to three times those for the inlet of a centrifugal impeller can be achieved with a properly and conservatively designed inducer. When coupled to a centrifugal impeller, the inducer offers excellent suction performance which can be effectively used to optimize pump efficiency, reduce pump size, and reduce pump cost. Four major efforts were undertaken during the five quarters of GFY 1976 to demonstrate and verify the inducer's suitability and applicability to LMFBR pumps, and to quantify the advantages of the inducer pump. The efforts are summarized

  14. BWR 200 % recirculation pump suction line break LOCA tests, RUNs 942 and 943 at ROSA-III without HPCS

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro; Tasaka, Kanji; Anoda, Yoshinari; Kumamaru, Hiroshige; Nakamura, Hideo; Yonomoto, Taisuke; Murata, Hideo; Koizumi, Yasuo

    1986-03-01

    This report presents the experimental results of RUNs 942 and 943 in ROSA-III program, which are 200 % recirculation pump suction line break LOCA tests with assumption of HPCS failure. The ROSA-III test facility simulates a BWR system with volume scale of 1/424 and has four half-length electrically heated fuel bundles, two active recirculation loops, ECCS's, and steam and feedwater systems. Effects of initial core void distribution and other fluid conditions on overall LOCA phenomena with special interest on transient core cooling phenomena were investigated by comparing the present test results with those of RUN 926, a 200 % suction line break test with standard initial fluid conditions. The initial core outlet quality was changed between 5 % and 43 %. As conclusions, (1) the initial lower core flow and higher void fraction affected significantly the core cooling conditions and resulted in earlier and higher PCT. (2) The lower plenum flashing temporarily contributed to cool down the core. (3) Flashing of remained hot water in the feedwater line affected slightly the pressure response and delayed the actuation of LPCI by 11 seconds. (4) The whole core was completely cooled down within 104 seconds after the LPCI actuation in these large break tests. (author)

  15. Application of a compressible flow solver and barotropic cavitation model for the evaluation of the suction head in a low specific speed centrifugal pump impeller channel

    International Nuclear Information System (INIS)

    Limbach, P; Müller, T; Skoda, R

    2015-01-01

    Commonly, for the simulation of cavitation in centrifugal pumps incompressible flow solvers with VOF kind cavitation models are applied. Since the source/sink terms of the void fraction transport equation are based on simplified bubble dynamics, empirical parameters may need to be adjusted to the particular pump operating point. In the present study a barotropic cavitation model, which is based solely on thermodynamic fluid properties and does not include any empirical parameters, is applied on a single flow channel of a pump impeller in combination with a time-explicit viscous compressible flow solver. The suction head curves (head drop) are compared to the results of an incompressible implicit standard industrial CFD tool and are predicted qualitatively correct by the barotropic model. (paper)

  16. Estimation of Residential Heat Pump Consumption for Flexibility Market Applications

    DEFF Research Database (Denmark)

    Kouzelis, Konstantinos; Tan, Zheng-Hua; Bak-Jensen, Birgitte

    2015-01-01

    load of a flexible device, namely a Heat Pump (HP), out of the aggregated energy consumption of a house. The main idea for accomplishing this, is a comparison of the flexible consumer with electrically similar non-flexible consumers. The methodology is based on machine learning techniques, probability...... theory and statistics. After presenting this methodology, the general trend of the HP consumption is estimated and an hour-ahead forecast is conducted by employing Seasonal Autoregressive Integrated Moving Average modeling. In this manner, the flexible consumption is predicted, establishing the basis......Recent technological advancements have facilitated the evolution of traditional distribution grids to smart grids. In a smart grid scenario, flexible devices are expected to aid the system in balancing the electric power in a technically and economically efficient way. To achieve this, the flexible...

  17. Pump cavitation and inducer design

    International Nuclear Information System (INIS)

    Heslenfeld, M.W.; Hes, M. de

    2002-01-01

    Details of past work on sodium pump development and cavitation studies executed mainly for SNR 300 were reported earlier. Among the requirements for large sodium pumps are long life (200000 hours up to 300000 hours) and small size of impeller and pump, fully meeting the process and design criteria. These criteria are the required 'Q, H, r characteristics' in combination with a low NPSH value and the avoidance of cavitation damage to the pump. The pump designer has to develop a sound hydraulic combination consisting of suction arrangement, impeller design and diffuser. On the other hand the designer is free to choose an optimal pump speed. The pump speed in its turn influences the rotor dynamic pump design and the pump drive. The introduction of the inducer as an integral part of the pump design is based on following advantages: no tip cavitation; (possible) cavitation bubbles move to the open centre due to centrifugal forces on the fluid; the head of the inducer improves the inlet conditions of the impeller. The aim of an inducer is the increase in the suction specific speed (SA value) of a pump whereby the inducer functions as a pressure source improving the impeller inlet conditions. With inducer-impeller combinations values up to SA=15000 are realistic. With the use of an inducer the overall pump sizes can be reduced with Ca. 30%. Pumps commonly available have SA values up to a maximum of ca. 10000. A development programme was executed for SNR 300 in order to reach an increase of the suction specific speed of the impeller from SA 8200 to SA 11000. Further studies to optimize pumps design for the follow up line introduced the 'inducer acting as a pre-impeller' development. This programme was executed in the period 1979-1981. At the FDO premises a scale 1 2.8 inducer impeller combination with a suction specific speed SA=15000 was developed, constructed and tested at the water test rig. This water test rig is equipped with a perspex pipe allowing also visualisation

  18. Determination of Volumetric Losses in Hydrodynamic Pump Using Numerical Modelling

    Directory of Open Access Journals (Sweden)

    Lukáš ZAVADIL

    2012-06-01

    Full Text Available This paper deals with the numerical modelling of the flow in the single-stage centrifugal pump. The main objective is to determine leakage losses through annular seals at the suction side of the pump. Leakage through a shaft seal is not included in the simulation. The amount of liquid that circulates from the impeller discharge back to suction of the pump is determined in dependence on the flow rate. Losses in the pump are further discussed as well as the possibility of their prediction.

  19. Inducer pumps for liquid metal reactor plants

    International Nuclear Information System (INIS)

    Jackson, E.D.

    2002-01-01

    Pumps proposed for liquid metal reactor plants typically use centrifugal impellers as the rotating element and are required to maintain a relatively low speed to keep the suction specific speed low enough to operate at the available net positive suction head (HPSH) and to avoid cavitation damage. These low speeds of operation require that the pump diameter increase and/or multiple stages be used to achieve the design head. This frequently results in a large, heavy, complex pump design. In addition, the low speed results in a larger drive motor size so that the resultant penalty to the plant designer is multiplied. The heavier pump can also result in further complications as, e.g., the difficulty in maintaining the first critical speed sufficiently above the pump operating range to provide margin for rotor dynamic stability. To overcome some of these disadvantages, it was proposed the use of inducer pumps for Liquid Metal Fast Breeder Reactor (LMFBR) plants. This paper discusses some of the advantages of the inducer pump and the development history of designing and testing these pumps both in water and sodium. The inducer pump is seen to be a sound concept with a strong technology base derived from the aerospace and ship propulsion industries. The superior suction performance capability of the inducer offers significant system design advantages, primarily a smaller, lighter weight, less complex pump design with resulting saving in cost. Extensive testing of these pumps has been conducted in both sodium and water to demonstrate the long-life capability with no cavitation damage occurring in those designs based on Rockwell's current design criteria. These tests have utilized multiple inspection and measurement approaches to accurately assess and identify any potential for cavitation damage, and these approaches have all concluded that no damage is occurring. Therefore, it is concluded that inducer pumps can be safely designed for long life operation in sodium with

  20. Magnetohydrodynamic peristaltic motion of a Newtonian fluid through porous walls through suction and injection

    Science.gov (United States)

    Sivaiah, R.; Hemadri Reddy, R.

    2017-11-01

    In this paper, we investigate the peristaltic transport of a conducting Newtonian fluid bounded by permeable walls with suction and injection moving with constant velocity of the wave in the wave frame of reference under the consideration of long wavelength and low Reynolds number. The analytical solution for the velocity field, pressure gradient and the frictional force are obtained. The effect of suction/injection parameter, amplitude ratio and the permeability parameter including slip on the flow quantities are discussed graphically. It is found that the greater the suction/injection parameter, the smaller the pressure rise against the pump works. Further, the pressure rise increases with increasing Magnetic parameter.

  1. Numerical simulation and experimental investigation on suction heating of a BOG compressor

    International Nuclear Information System (INIS)

    Jia, Xiaohan; Zhao, Bin; Feng, Jianmei; Zheng, Sulu; Peng, Xueyuan

    2016-01-01

    Highlights: • An investigation focusing on suction heating of a BOG compressor is carried out. • There is frost on the cylinder cover as the compressor at lower suction temperature. • The suction and discharge flow rate decrease with rising suction temperature. • The volumetric efficiency has a maximum value with increasing suction temperature. • The temperature coefficient increased with suction temperature or rotational speed. - Abstract: One of the key components of a liquefied natural gas (LNG) receiving terminal is the boil-off gas (BOG) compressor, which is used to pump out the BOG from the LNG storage tank to ensure safety in the transportation and receiving systems. Owing to the ultra-low suction temperature, the heat exchange between the intake gas and the cylinder, piston, and cylinder cover cannot be ignored as in normal conditions. This paper presents an investigation focusing on suction heating of the BOG compressor. A finite element model with dynamic mesh was established to simulate the suction process. At the same time, a performance test rig was built to study the characteristics of the BOG compressor under low suction temperature conditions and verify the numerical model. Consequently, the results of the simulation were in good agreement with experimental results. Both results implied that the temperature of cylinder surface increased starting from the cylinder cover to the crankcase. In addition, at lower suction temperature, the temperature difference between various points on the cylinder surface and cylinder cover was much larger than that at higher suction temperature. With increasing suction temperature, the temperature coefficient increased markedly, and the difference between gas temperatures at the beginning and end of the suction process, as well as the compressor flow rate, decreased significantly; however, the volumetric efficiency increased first and then decreased. Furthermore, the temperature coefficient clearly increased

  2. Comparative study of the characteristics of some suction devices for gas sampling applications; Etude comparative des caracteristiques de quelques dispositifs d'aspiration a l'usage des prelevements de gaz

    Energy Technology Data Exchange (ETDEWEB)

    Donguy, R.; Drouet, J.

    1959-06-15

    Gas sampling (used to determine the characteristics of dusts or aerosols contained in a gas) needs a suction device. In order to select the right device and the right conditions of use, the characteristics and performances of various suction devices (helicoidal and centrifugal aspirators, air pumps, volumetric pumps) have been experimentally measured: flow rate, head loss, sampling volume and duration, aerosol and dust concentration, gas density, nature of the gas, suction circuit configuration, etc.

  3. 46 CFR 56.50-45 - Circulating pumps.

    Science.gov (United States)

    2010-10-01

    ... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-45 Circulating pumps. (a) A main circulating pump and emergency means for circulating water through the main condenser shall be provided. The... circulating pump and the condenser. (b) Independent sea suctions shall be provided for the main circulating...

  4. Liquid sodium pumps

    International Nuclear Information System (INIS)

    Allen, H.G.

    1985-01-01

    The pump for use in a nuclear reactor cooling system comprises a booster stage impeller for drawing the liquid through the inlet. A diffuser is affixedly disposed within the pump housing to convert the kinetic pressure imparted to the liquid into increased static pressure. A main stage impeller is rotatively driven by a pump motor at a relatively high speed to impart a relatively high static pressure to the liquid and for discharging the liquid at a relatively high static pressure. A hydraulic coupling is disposed remotely from the liquid path for hydraulically coupling the main stage impeller and the booster stage impeller to rotate the booster stage impeller at a relatively low speed to maintain the low net positive suction pressure applied to the liquid at the inlet greater than the vapor pressure of the liquid and to ensure that the low net positive suction heat, as established by the main stage impeller exceeds the vapor pressure. The coupling comprises a grooved drum which rotates between inner and outer drag coupling members. In a modification the coupling comprises a torque converter. (author)

  5. Tissue holding device for use during surgical procedure, has contact body with suction foot and suction mouth that is surrounded by rim, and suction pipe connected to suction chamber

    OpenAIRE

    Vonck, D.; Goossens, R.H.M.; Flipsen, S.F.J.; Jakimowicz, J.J.; Van der Putten, E.P.W.

    2009-01-01

    The device has a locking ring (5), a connector (6), and a contact body (1) with a suction foot and a suction mouth (8), where the mouth is surrounded by a rim (10), which is substantially located in a plane of the suction foot. A suction chamber (9) has a sieve-shaped inner wall (2) and a transparent side wall, and a suction pipe (11) is connected to the chamber.

  6. Parallel operation of primary sodium pumps in FBTR

    International Nuclear Information System (INIS)

    Athmalingam, S.; Ellappan, T.R.; Vaidyanathan, G.; Chetal, S.C.; Bhoje, S.B.

    1994-01-01

    Sodium pumps used in the primary main circuit of Fast Breeder Test Reactor (FBTR) are centrifugal pumps. These pumps have a free level of sodium with a cover gas above it to simplify the pump seal arrangement. The sodium level in the pumps will vary based on the flow. The minimum level is governed by consideration of gas entrainment and net positive suction head (NPSH) to the pump while the maximum level is limited by sodium entering the pump tank gas line. There is a special feature in these pumps in that a small portion of the pump outlet sodium flow is led back into the suction chamber to maintain level and avoid gas entrainment. A control valve in this line helps in controlling the level at the desired value. With parallel operation of two sodium pumps a study was conducted to find the regions of safe operation of the two pumps. The purpose of this paper is to give the various design features and methodology of the analysis to arrive at the limiting condition of operation for the different operating states of the two pumps and the effect of pump speed variations on the fluctuations in sodium flows. (author). 6 figs

  7. Jet pump assisted artery

    Science.gov (United States)

    1975-01-01

    A procedure for priming an arterial heat pump is reported; the procedure also has a means for maintaining the pump in a primed state. This concept utilizes a capillary driven jet pump to create the necessary suction to fill the artery. Basically, the jet pump consists of a venturi or nozzle-diffuser type constriction in the vapor passage. The throat of this venturi is connected to the artery. Thus vapor, gas, liquid, or a combination of the above is pumped continuously out of the artery. As a result, the artery is always filled with liquid and an adequate supply of working fluid is provided to the evaporator of the heat pipe.

  8. Main boiler feed pump for fast breeder test reactor. Failure analysis and remedial measures

    International Nuclear Information System (INIS)

    Iyer, M.A.K.; Chande, S.K.; Raghuvir, A.D.; Baskar, S.; Kale, R.D.

    1994-01-01

    A small capacity ten stage 670 kw feed water pump is used for supplying feed water at a temperature of 190 deg C to a once through steam generator in the Fast Breeder Test Reactor at Kalpakkam. During preparatory heating up stage to commission the steam generator the pump suffered a severe loss of suction which resulted in failure of hydrostatic journal bearings and extensive damage to pump internals. This paper discusses the detailed mechanism of loss of suction, details of damage to the pump and various modifications carried out to prevent recurrence of the problem. (author). 4 refs., 3 figs., 2 tabs

  9. Influence of building and supply conditions on coolant pumps and the various coolant pump designs for cooling towers

    International Nuclear Information System (INIS)

    Holzhueter, E.; Migod, A.; Siekmann, H.

    1977-01-01

    This contribution tries to present the various factors influencing the design of cooling tower pumps. As cooling tower pumps are very often designed as concrete speral casing pumps, the suction bend construction often offers itself. The running wheel of cooling tower pumps is usually of semi-axial design, whereby one has to differ between rigid, adjustable, and resetable running wheels. Finally, the type of cooling system and the nominal width are decisive for either the construction type of the spiral casing pump or the tubular type pump. Both methods are compared in a critical way. (orig.) [de

  10. Characterisation of textile shape and position upstream of a wastewater pump under different part load conditions

    DEFF Research Database (Denmark)

    Jensen, Anna Lyhne; Sørensen, Henrik; Rosendahl, Lasse Aistrup

    2018-01-01

    Accumulations of sanitary textile materials often lead to clogging of pumps in the wastewater system. Simulation of clogging phenomena may help to identify means of reducing the risk of clogging. In order to provide realistic initial conditions for clogging simulations, this study characterises...... textiles in artificial wastewater in the suction pipe to a dry-installed pump at nine different operating points. The textiles are recorded approximately 3.5 pipe diameters from the pump inlet and approximately three pipe diameters from the suction pipe bend at pipe Reynolds numbers in the range 300...

  11. Radial loads and axial thrusts on centrifugal pumps

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The proceedings of a seminar organised by the Power Industries Division of the IMechE are presented in this text. Complete contents: Review of parameters influencing hydraulic forces on centrifugal impellers; The effect of fluid forces at various operation conditions on the vibrations of vertical turbine pumps; A review of the pump rotor axial equilibrium problem - some case studies; Dynamic hydraulic loading on a centrifugal pump impeller; Experimental research on axial thrust loads of double suction centrifugal pumps; A comparison of pressure distribution and radial loads on centrifugal pumps; A theoretical and experimental investigation of axial thrusts within a multi-stage centrifugal pump

  12. Conceptual Design of Portable Filtered Air Suction Systems For Prevention of Released Radioactive Gas under Severe Accidents of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Beom W.; Choi, Su Y.; Yim, Man S.; Rim, Chun T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    It becomes evident that severe accidents may occur by unexpected disasters such as tsunami, heavy flood, or terror. Once radioactive material is released from NPP through severe accidents, there are no ways to prevent the released radioactive gas spreading in the air. As a remedy for this problem, the idea on the portable filtered air suction system (PoFASS) for the prevention of released radioactive gas under severe accidents was proposed. In this paper, the conceptual design of a PoFASS focusing on the number of robot fingers and robot arm rods are proposed. In order to design a flexible robot suction nozzle, mathematical models for the gaps which represent the lifted heights of extensible covers for given convex shapes of pipes and for the covered areas are developed. In addition, the system requirements for the design of the robot arms of PoFASS are proposed, which determine the accessible range of leakage points of released radioactive gas. In this paper, the conceptual designs of the flexible robot suction nozzle and robot arm have been conducted. As a result, the minimum number of robot fingers and robot arm rods are defined to be four and three, respectively. For further works, extensible cover designs on the flexible robot suction nozzle and the application of the PoFASS to the inside of NPP should be studied because the radioactive gas may be released from connection pipes between the containment building and auxiliary buildings.

  13. Optimal hydraulic design of new-type shaft tubular pumping system

    International Nuclear Information System (INIS)

    Zhu, H G; Zhang, R T; Zhou, J R

    2012-01-01

    Based on the characteristics of large flow rate, low-head, short annual operation time and high reliability of city flood-control pumping stations, a new-type shaft tubular pumping system featuring shaft suction box, siphon-type discharge passage with vacuum breaker as cutoff device was put forward, which possesses such advantages as simpler structure, reliable cutoff and higher energy performance. According to the design parameters of a city flood control pumping station, a numerical computation model was set up including shaft-type suction box, siphon-type discharge passage, pump impeller and guide vanes. By using commercial CFD software Fluent, RNG κ-ε turbulence model was adopted to close the three-dimensional time-averaged incompressible N-S equations. After completing optimal hydraulic design of shaft-type suction box, and keeping the parameters of total length, maximum width and outlet section unchanged, siphon-type discharge passages of three hump locations and three hump heights were designed and numerical analysis on the 9 hydraulic design schemes of pumping system were proceeded. The computational results show that the changing of hump locations and hump heights directly affects the internal flow patterns of discharge passages and hydraulic performances of the system, and when hump is located 3.66D from the inlet section and hump height is about 0.65D (D is the diameter of pump impeller), the new-type shaft tubular pumping system achieves better energy performances. A pumping system model test of the optimal designed scheme was carried out. The result shows that the highest pumping system efficiency reaches 75.96%, and when at design head of 1.15m the flow rate and system efficiency were 0.304m 3 /s and 63.10%, respectively. Thus, the validity of optimal design method was verified by the model test, and a solid foundation was laid for the application and extension of the new-type shaft tubular pumping system.

  14. Water Flow Performance of a Superscale Model of the Fastrac Liquid Oxygen Pump

    Science.gov (United States)

    Skelley, Stephen; Zoladz, Thomas

    2001-01-01

    As part of the National Aeronautics and Space Administration's ongoing effort to lower the cost of access to space, the Marshall Space Flight Center has developed a rocket engine with 60,000 pounds of thrust for use on the Reusable Launch Vehicle technology demonstrator slated for launch in 2000. This gas generator cycle engine, known as the Fastrac engine, uses liquid oxygen and RP-1 for propellants and includes single stage liquid oxygen and RP-1 pumps and a single stage supersonic turbine on a common shaft. The turbopump design effort included the first use and application of new suction capability prediction codes and three-dimensional blade generation codes in an attempt to reduce the turbomachinery design and certification costs typically associated with rocket engine development. To verify the pump's predicted cavitation performance, a water flow test of a superscale model of the Fastrac liquid oxygen pump was conducted to experimentally evaluate the liquid oxygen pump's performance at and around the design point. The water flow test article replicated the flow path of the Fastrac liquid oxygen pump in a 1.582x scale model, including scaled seal clearances for correct leakage flow at a model operating speed of 5000 revolutions per minute. Flow entered the 3-blade axial-flow inducer, transitioned to a shrouded, 6- blade radial impeller, and discharged into a vaneless radial diffuser and collection volute. The test article included approximately 50 total and static pressure measurement locations as well as flush-mounted, high frequency pressure transducers for complete mapping of the pressure environment. The primary objectives of the water flow test were to measure the steady-state and dynamic pressure environment of the liquid oxygen pump versus flow coefficient, suction specific speed, and back face leakage flow rate. Initial results showed acceptable correlation between the predicted and experimentally measured pump head rise at low suction specific speeds

  15. Test specification for decant pump and winch assembly

    International Nuclear Information System (INIS)

    Staehr, T.W.

    1994-01-01

    This specification provides the requirements for testing of the vertical turbine decant pump including the floating suction arm with load sensing winch control, instrumentation and the associated PLC/PC control system

  16. Booster Pump Performance Analysis Towards Rotation Of Impeller For CSD Dredger Type

    Directory of Open Access Journals (Sweden)

    Tony Bambang Musriyadi

    2017-12-01

    Full Text Available Dredger are a vessel for lift materials from sub surface to another place above the water surface. Dredger divided into some types such Suction Dredger, Bucket Dredger, Backhoe Dredger, and Water Injection Dredger. Cutter Suction Dredger is equipped with a rotating cutter head, for cutting and fragmenting hard soils. The soil is sucked up by means of dredge pumps, and discharged through a floating pipeline and pipes on shore, to a deposit area. In some cases, the material is discharged into split hopper barges that are moored alongside the Cutter Suction Dredger. These split hopper barges unload the soil at the deposit area. The most important part of dredger are the pump unit, NPSH is needed to figure the pump performance ability and how the efficiency number of the pump. Booster pump performance analysist are needed to mantain the pump's performance and efficiency. This thesis are describe about drawing process and computerized simulation at Ansys Software for pump performance with 3 different fluid types and 5 variations of impeller rotation. The number of NPSHa are 6.8 m and 2.8 for the NPSHr. Based on the pure water state, the lowest RPM value of 300 was obtained with V = 1.1366 m / s and Q = 1227.52 m3 / h, the highest RPM value of 600 with the result v = 1.1259 m / s and Q = 1215.97 m3 / h. Then the pumps used in this final project are more efficiently used for fluid types which tend to be condensed from the liquid, and less efficient for use in the state of pure water fluid

  17. Pump element for a tube pump

    DEFF Research Database (Denmark)

    2011-01-01

    The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... relative to the rod element so as to allow for a fluid flow in the tube through the first valve member, along the rod element, and through the second valve member. The tube comprises an at least partly flexible tube portion between the valve members such that a repeated deformation of the flexible tube...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...

  18. Theoretical Model for the Performance of Liquid Ring Pump Based on the Actual Operating Cycle

    Directory of Open Access Journals (Sweden)

    Si Huang

    2017-01-01

    Full Text Available Liquid ring pump is widely applied in many industry fields due to the advantages of isothermal compression process, simple structure, and liquid-sealing. Based on the actual operating cycle of “suction-compression-discharge-expansion,” a universal theoretical model for performance of liquid ring pump was established in this study, to solve the problem that the theoretical models deviated from the actual performance in operating cycle. With the major geometric parameters and operating conditions of a liquid ring pump, the performance parameters such as the actual capacity for suction and discharge, shaft power, and global efficiency can be conveniently predicted by the proposed theoretical model, without the limitation of empiric range, performance data, or the detailed 3D geometry of pumps. The proposed theoretical model was verified by experimental performances of liquid ring pumps and could provide a feasible tool for the application of liquid ring pump.

  19. Gravity separation of pericardial fat in cardiotomy suction blood: an in vitro model.

    Science.gov (United States)

    Kinard, M Rhett; Shackelford, Anthony G; Sistino, Joseph J

    2009-06-01

    Fat emboli generated during cardiac surgery have been shown to cause neurologic complications in patients postoperatively. Cardiotomy suction has been known to be a large generator of emboli. This study will examine the efficacy of a separation technique in which the cardiotomy suction blood is stored in a cardiotomy reservoir for various time intervals to allow spontaneous separation of fat from blood by density. Soybean oil was added to heparinized porcine blood to simulate the blood of a patient with hypertriglyceridemia (> 150 mg/dL). Roller pump suction was used to transfer the room temperature blood into the cardiotomy reservoir. Blood was removed from the reservoir in 200-mL aliquots at 0, 15, 30 45, and 60 minutes. Samples were taken at each interval and centrifuged to facilitate further separation of liquid fat. Fat content in each sample was determined by a point-of-care triglyceride analyzer. Three trials were conducted for a total of 30 samples. The 0-minute group was considered a baseline and was compared to the other four times. Fat concentration was reduced significantly in the 45- and 60-minute groups compared to the 0-, 15-, and 30-minute groups (p Gravity separation of cardiotomy suction blood is effective; however, it may require retention of blood for more time than is clinically acceptable during a routing coronary artery bypass graft surgery.

  20. Structural analysis: Flexible receiver yoke brace for the 241SY101 mixer pump

    International Nuclear Information System (INIS)

    Jones, K.M.

    1994-01-01

    This report documents the structural analysis of the flexible-receiver yoke brace that will be used to maintain the mixer pump lifting yoke in a vertical position during the removal of the mixer pump from waste tank 241SY101. During the removal process, the crane is connected to a lifting yoke which is attached to the lifting on the mounting flange of the mixer pump. The pump then can be lifted from the tank. At one point in the removal procedure, the crane will be disconnected from the lifting yoke. At this time, it is possible for the lifting yoke to rotate around the pinned connection between it and the pump if it is subjected to a horizontal load. To prevent the rotation of the lifting yoke, the yoke brace was designed to maintain the yoke in a vertical position while it is disconnected from the crane. This analysis addressed the adequacy of the yoke brace to provide support for the lifting yoke during high winds and a seismic event. The results of this analysis show that, when subjected to a combined design wind and seismic load, the yoke brace design is acceptable to maintain the lifting yoke in a vertical position when the yoke is disconnected from the crane

  1. Physiological control of dual rotary pumps as a biventricular assist device using a master/slave approach.

    Science.gov (United States)

    Stevens, Michael C; Wilson, Stephen; Bradley, Andrew; Fraser, John; Timms, Daniel

    2014-09-01

    Dual rotary left ventricular assist devices (LVADs) can provide biventricular mechanical support during heart failure. Coordination of left and right pump speeds is critical not only to avoid ventricular suction and to match cardiac output with demand, but also to ensure balanced systemic and pulmonary circulatory volumes. Physiological control systems for dual LVADs must meet these objectives across a variety of clinical scenarios by automatically adjusting left and right pump speeds to avoid catastrophic physiological consequences. In this study we evaluate a novel master/slave physiological control system for dual LVADs. The master controller is a Starling-like controller, which sets flow rate as a function of end-diastolic ventricular pressure (EDP). The slave controller then maintains a linear relationship between right and left EDPs. Both left/right and right/left master/slave combinations were evaluated by subjecting them to four clinical scenarios (rest, postural change, Valsalva maneuver, and exercise) simulated in a mock circulation loop. The controller's performance was compared to constant-rotational-speed control and two other dual LVAD control systems: dual constant inlet pressure and dual Frank-Starling control. The results showed that the master/slave physiological control system produced fewer suction events than constant-speed control (6 vs. 62 over a 7-min period). Left/right master/slave control had lower risk of pulmonary congestion than the other control systems, as indicated by lower maximum EDPs (15.1 vs. 25.2-28.4 mm Hg). During exercise, master/slave control increased total flow from 5.2 to 10.1 L/min, primarily due to an increase of left and right pump speed. Use of the left pump as the master resulted in fewer suction events and lower EDPs than when the right pump was master. Based on these results, master/slave control using the left pump as the master automatically adjusts pump speed to avoid suction and increases pump flow

  2. Hydrostatic radial bearing of centrifugal pump

    International Nuclear Information System (INIS)

    Skalicky, A.

    1976-01-01

    A hydrostatic radial pump is described characterized by the fact that part of the medium off-taken from delivery is used as a lubricating medium. Two additional bodies are placed alongside a hydrostatic bearing with coils in between them and the pump shaft; the coils have an opposite pitch. The feed channel for the hydrostatic bearing pocket is linked to delivery. The coil outlets are connected to the pump suction unit. Two rotating coils placed alongside the hydrostatic bearing will considerably simplify the communication channel design and reduce the dependence on the pump shaft deflections. The addition of another rotating coil in the close vicinity of the pump shaft or directly on the shaft further increases the efficiency. The bearing can be used in designing vertical circulating pumps for the cooling circuits of nuclear reactors. (J.B.)

  3. Hydroponic Feed With Suction

    Science.gov (United States)

    Cox, William M.; Brown, Christopher S.; Dreschel, Thomas W.

    1994-01-01

    Placing nutrient solution under suction increases growth. Foam plug seals growing stem of plant, making it possible to maintain suction in nutrient liquid around roots. Jar wrapped in black tape to keep out light. Potential use in terrestrial applications in arid climates or in labor-intensive agricultural situations.

  4. A method for emergency flooding of the gland in the main circulating pump of pressurized water reactors and the connection therefor

    International Nuclear Information System (INIS)

    Skalicky, A.

    1978-01-01

    A method is described for the emergency flooding of the main circulating pumps of a pressurized water reactor such that in pressure drop in the flooded gland owing to pump suction, the pump head is connected by the pressure difference action to the flooding gland pipe, this via the heat sink and the filter of the emergency flooding circuit connected to the pump head. The emergency flooding circuit consisting of a pressure reducing valve, a check valve and a stop valve is connected to the pump head, behind the heat sink and the filter. The pressure reducing valve separates two pressure spaces. The former is connected to the pump head via the check valve and to the flooding pipe via the stop valve and the check valve. The latter is connected to the suction pump. (B.S.)

  5. Reactor coolant pumps for nuclear reactors

    International Nuclear Information System (INIS)

    Harand, E.; Richter, G.; Tschoepel, G.

    1975-01-01

    A brake for the pump rotor of a main coolant pump or a shutoff member on the pump are provided in order to prevent excess speeds of the pump rotor. Such excess speeds may occur in PWR type reactors with water at a pressure below, e.g., 150 bars if there is leakage from a coolant line associated with the main coolant pump. As a brake, a centrifugal brake depending upon the pump speed or a brake ring arranged on the pump housing and acting on the pump rotor, which ring would be activated by pressure differentials in the pump, may be used. If the pressure differences between suction and pressure sockets are very small, a controlled hydraulic increase of the pressure force on the brake may also be provided. Furthermore, a turbine brake may be provided. A slide which is automatically movable in closing position along the pump rotor axis is used as a shutoff element. It is of cylindrical configuration and is arranged concentrically with the rotor axis. (DG) [de

  6. Analysis Of Primary Coolant Suction Side Pressure In The Delay Chamber Of The RSG-GAS

    International Nuclear Information System (INIS)

    Dibyo, Sukmanto

    2000-01-01

    Delay chamber is a tank to delay flow that located in the primary cooling suction side of RSG-GAS. A void occurred when operation reactor caused by too high the delta P at inlet suction pump. The condition may be avoided by using one line mode of the cooling flow. The analysis show that void volume in the delay chamber is occurred because the coolant negative pressure lowers the saturation pressure should be avoided though decreasing the delta P until about 0.1 bar at about 45 exp 0 C. Solution suggested are to use bypass flow from the spent fuel to the delay chamber. Coolant temperature can be also decreased by decreasing the power level of the reactor as well as improving the heat exchanger and cooling tower performances

  7. Dynamic stiffness of suction caissons

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten; Andersen, Lars

    The purpose of this report is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigation is limited to a determination of the vertical dynamic stiffness of suction caissons. The soil surrounding the foundation is homogenous with linear...... viscoelastic properties. The dynamic stiffness of the suction caisson is expressed by dimensionless frequency-dependent dynamic stiffness coefficients corresponding to the vertical degree of freedom. The dynamic stiffness coefficients for the foundations are evaluated by means of a dynamic three...

  8. A numerical study on the influence of gas-liquid two phase flow on the rotary pump performances

    International Nuclear Information System (INIS)

    Miao, T C; Liu, Y Y; Zhao, F; Wang, L Q

    2013-01-01

    Rotary pump can be used in many fields because of its strong self-priming ability. Many factors may cause the medium in rotary pump system containing gas-liquid two phase. And the suction capacity of rotary pump will decrease sharply in these situations. To study the internal flow mechanism of rotary pump when transporting medium containing gas, the gas-liquid two phase flow in the rotary pump system has been simulated using VOF model under different gas fractions. And the interaction between rotary pump and the pipeline has been considered. The simulation results coincide well with the theoretical calculation results, and the distribution of the flow field match well with the Mandhane flow pattern map. The main conclusions are as follows: with the increase of gas fraction, the flow pattern in the pipeline has the following evolutionary trend (bubble – plug – slug – wavy), and the suction capacity of the pump will decrease. It is mainly because gas medium can fill the partial vacuum produced by the rotor motion easily and is easier to have backflow

  9. 46 CFR 56.50-35 - Condensate pumps.

    Science.gov (United States)

    2010-10-01

    ... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-35 Condensate pumps. Two means shall be provided for discharging the condensate from the main condenser, one of which shall be mechanically... suction from the condenser and a discharge to the feed tank, it may be accepted as an independent...

  10. Suction is kid's play: extremely fast suction in newborn seahorses

    Science.gov (United States)

    Van Wassenbergh, Sam; Roos, Gert; Genbrugge, Annelies; Leysen, Heleen; Aerts, Peter; Adriaens, Dominique; Herrel, Anthony

    2009-01-01

    Ongoing anatomical development typically results in a gradual maturation of the feeding movements from larval to adult fishes. Adult seahorses are known to capture prey by rotating their long-snouted head extremely quickly towards prey, followed by powerful suction. This type of suction is powered by elastic recoil and requires very precise coordination of the movements of the associated feeding structures, making it an all-or-none phenomenon. Here, we show that newborn Hippocampus reidi are able to successfully feed using an extremely rapid and powerful snout rotation combined with a high-volume suction, surpassing that observed in adult seahorses. An inverse dynamic analysis shows that an elastic recoil mechanism is also used to power head rotation in newborn H. reidi. This illustrates how extreme levels of performance in highly complex musculoskeletal systems can be present at birth given a delayed birth and rapid development of functionally important structures. The fact that the head skeleton of newborn seahorses is still largely cartilaginous may not be problematic because the hydrodynamic stress on the rotating snout appeared considerably lower than in adult syngnathids. PMID:19324657

  11. 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.

  12. Results of Investigations of Failures of Geothermal Direct Use Well Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Culver, G.

    1994-12-01

    Failures of 13 geothermal direct-use well pumps were investigated and information obtained about an additional 5 pumps that have been in service up to 23 years, but have not failed. Pumps with extra long lateral and variable-speed drives had the highest correlation with reduced time in service. There appears to be at least circumstantial evidence that recirculation may be a cause of reduced pump life. If recirculation is a cause of pump failures, pump specifiers will need to be more aware of minimum flow conditions as well as maximum flow conditions when specifying pumps. Over-sizing pumps and the tendency to specify pumps with high flow and low Net Positive Suction Head (NPSH) could lead to increased problems with recirculation.

  13. PERBEDAAN PARAMETER KARDIOPULMONAL SETELAH TINDAKAN OPEN SUCTION

    Directory of Open Access Journals (Sweden)

    Muhamat Nofiyanto

    2013-12-01

    Full Text Available Background: Endotracheal suctioning is often performed by nurses and beneficial for critically ill patients. Suctioning is essential for removing secretions, maintaining airway patency and prevent unexpected complications. Open suctioning is performed by disconnecting patients with the ventilator. Suctioning not only removed secretions in the airway but also oxygen. Suctioning must be done correctly, safely, effectively and efficiently to prevent unexpected events in critically ill patients. Objective: This study aimed to determine differences on cardiopulmonary parameters after open suction in critically ill patients Methods: The study design was comparatif cross sectional analytic approach, using one group pre test and post test. The sample of the research amounted to 34 people, using purposive sampling technique. Catheter size 14 Fr on ETT number 7 mm used in this research to performed endotracheal suctioning. Cardiopulmonary parameters (Heart rate/ HR, respiratory rate/RR, oxygen saturation/SpO2, systolic blood pressure/ SBP and diastolic blood pressure/DBP measured by pulse oxymeter and bedside monitor before suction and immediately thereafter. Results: The results showed increase average heart rate 6.412 (from 106.62 into 113.03, Respiratory rate has increased 4.971 (from 20.62 into 25.59, SpO2 decreased 1.68 (from 99.09 into 97.41, and systolic blood pressure increased 5.71 (from 118.29 into 124.00 after performed open suction. The results of paired t-test statistical analysis (for RR, HR obtained a < 0.05 (0.000, whereas Wilcoxon statistical analysis (for SpO2, SBP obtained a < 0.05 (0.000 and 0.001. So it can be said that the difference cardiopulmonary parameters was statistically significant after perfomed open suction in critically ill patients.

  14. Optimization of residual heat removal pump axial thrust and axial bearing

    International Nuclear Information System (INIS)

    Schubert, F.

    1996-01-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies

  15. Optimization of residual heat removal pump axial thrust and axial bearing

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, F.

    1996-12-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies.

  16. Pre-compression volume on flow ripple reduction of a piston pump

    Science.gov (United States)

    Xu, Bing; Song, Yuechao; Yang, Huayong

    2013-11-01

    Axial piston pump with pre-compression volume(PCV) has lower flow ripple in large scale of operating condition than the traditional one. However, there is lack of precise simulation model of the axial piston pump with PCV, so the parameters of PCV are difficult to be determined. A finite element simulation model for piston pump with PCV is built by considering the piston movement, the fluid characteristic(including fluid compressibility and viscosity) and the leakage flow rate. Then a test of the pump flow ripple called the secondary source method is implemented to validate the simulation model. Thirdly, by comparing results among the simulation results, test results and results from other publications at the same operating condition, the simulation model is validated and used in optimizing the axial piston pump with PCV. According to the pump flow ripples obtained by the simulation model with different PCV parameters, the flow ripple is the smallest when the PCV angle is 13°, the PCV volume is 1.3×10-4 m3 at such operating condition that the pump suction pressure is 2 MPa, the pump delivery pressure 15 MPa, the pump speed 1 000 r/min, the swash plate angle 13°. At the same time, the flow ripple can be reduced when the pump suction pressure is 2 MPa, the pump delivery pressure is 5 MPa,15 MPa, 22 MPa, pump speed is 400 r/min, 1 000 r/min, 1 500 r/min, the swash plate angle is 11°, 13°, 15° and 17°, respectively. The finite element simulation model proposed provides a method for optimizing the PCV structure and guiding for designing a quieter axial piston pump.

  17. Suction caissons subjected to monotonic combined loading

    DEFF Research Database (Denmark)

    Penzes, P.; Jensen, M.R.; Zania, Varvara

    2016-01-01

    Suction caissons are being increasingly used as offshore foundation solutions in shallow and intermediate water depths. The convenient installation method through the application of suction has rendered this type of foundation as an attractive alternative to the more traditional monopile foundation...... for offshore wind turbines. The combined loading imposed typically to a suction caisson has led to the estimation of their bearing capacity by means of 3D failure envelopes. This study aims to analyse the behaviour of suction caissons for offshore wind turbines subjected to combined loading. Finite element...

  18. Scaled multiple holes suction tip for microneurosurgery; Technical note

    Directory of Open Access Journals (Sweden)

    Abdolkarim Rahmanian, Associate Professor of Neurosurgery

    2017-12-01

    Conclusion: The new suction tip permits easy and precise adjustment of suction power in microneurosirgical operations. Our scaled 3 and 4-hole suction tip is a simple and useful device for controlling the suction power during the microneurosurgeical procedures.

  19. Thermodynamic analysis of a minimum maintenance solar pump

    Energy Technology Data Exchange (ETDEWEB)

    Brew-Hammond, A.; Roullier, J.; Appeagyei-Kissi, D. (University of Science and Technology, Kumasi (Ghana))

    1993-10-01

    The Minimum Maintenance Solar Pump (MMSP) is a solar-thermal pumping system which operates on a diurnal cycle with solar heating and nocturnal cooling/suction. Several prototypes of the MMSP have been constructed in Ghana, Canada and France with varying degrees of success. A thermodynamic analysis of the MMSP has yielded an expression which is used with the aid of a micro-computer to predict the performance characteristics of the MMSP. The predictions compare favourably with available experimental results and indicate that it is imperative for temperatures well above 80[sup o]C to be obtained in the MMSP if pumping is to be achieved at heads of practical significance. (author)

  20. Evaluation of hypopharyngeal suction to eliminate aspiration: the Retro-Esophageal Suction (REScue) catheter.

    Science.gov (United States)

    Belafsky, Peter C; Mehdizadeh, O B; Ledgerwood, L; Kuhn, M

    2015-02-01

    Profound oropharyngeal dysphagia (OPD) is common and costly. Treatment options are limited. The purpose of this investigation was to evaluate the utility of hypopharyngeal suction at the upper esophageal sphincter (UES) to eliminate aspiration. Five different catheters were passed retrograde up the esophagus and positioned at the UES in a cadaver model of profound OPD. Suction was affixed to each catheter. 10 cc of barium was administered into the pyriform sinus, and videofluoroscopy was utilized to evaluate the presence of aspiration. 6 trials were administered per catheter and for a no catheter control. The outcome measures were the incidence of aspiration, the NIH Swallow Safety Scale (NIH-SSS), and UES opening. Control trials with no suction resulted in an aspiration rate of 100 % (6/6 trials). Negative pressure through 16, 18, 24, and 30 Fr catheter resulted in an aspiration rate of 0 % (0/24 trials; p  0.05). The mean NIH-SSS improved from 7.0 (±0.0) in the control to 0 (±0.0) with hypopharyngeal suction (18 Fr nasogastric catheter; p 12 Fr) at the level of the UES reduced aspiration by 100 % and significantly increased UES opening in a cadaveric model of profound oropharyngeal dysphagia.

  1. Dynamic lateral response of suction caissons

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara

    2017-01-01

    Deeper water installations of offshore wind turbines may be supported by jacket structures. This study investigates the dynamic response of suction caissons for jackets by analysing 3D finite element models in the frequency domain. The numerical modelling was firstly validated by analytical...... solutions for pile foundations. Groups of crucial dimensionless parameters related to the soil profile and the foundation geometry are identified and their effects on the response of suction caissons are studied. Static stiffness coefficients are presented in a form of mathematical formulas obtained...... by fitting the numerical results, pertaining foundations with different slenderness ratios and embedded in different soil profiles. Sensitivity of the dynamic impedances of suction caissons on the skirt length was showed in this study. Moreover, the results for the suction caissons indicated that the overall...

  2. Diagnosis of Centrifugal Pump Faults Using Vibration Methods

    International Nuclear Information System (INIS)

    Albraik, A; Althobiani, F; Gu, F; Ball, A

    2012-01-01

    Pumps are the largest single consumer of power in industry. This means that faulty pumps cause a high rate of energy loss with associated performance degradation, high vibration levels and significant noise radiation. This paper investigates the correlations between pump performance parameters including head, flow rate and energy consumption and surface vibration for the purpose of both pump condition monitoring and performance assessment. Using an in-house pump system, a number of experiments have been carried out on a centrifugal pump system using five impellers: one in good condition and four others with different defects, and at different flow rates for the comparison purposes. The results have shown that each defective impeller performance curve (showing flow, head, efficiency and NPSH (Net Positive Suction Head) is different from the benchmark curve showing the performance of the impeller in good condition. The exterior vibration responses were investigated to extract several key features to represent the healthy pump condition, pump operating condition and pump energy consumption. In combination, these parameter allow an optimal decision for pump overhaul to be made.

  3. Diagnosis of Centrifugal Pump Faults Using Vibration Methods

    Science.gov (United States)

    Albraik, A.; Althobiani, F.; Gu, F.; Ball, A.

    2012-05-01

    Pumps are the largest single consumer of power in industry. This means that faulty pumps cause a high rate of energy loss with associated performance degradation, high vibration levels and significant noise radiation. This paper investigates the correlations between pump performance parameters including head, flow rate and energy consumption and surface vibration for the purpose of both pump condition monitoring and performance assessment. Using an in-house pump system, a number of experiments have been carried out on a centrifugal pump system using five impellers: one in good condition and four others with different defects, and at different flow rates for the comparison purposes. The results have shown that each defective impeller performance curve (showing flow, head, efficiency and NPSH (Net Positive Suction Head) is different from the benchmark curve showing the performance of the impeller in good condition. The exterior vibration responses were investigated to extract several key features to represent the healthy pump condition, pump operating condition and pump energy consumption. In combination, these parameter allow an optimal decision for pump overhaul to be made [1].

  4. Analysis of data obtained in two-phase flow tests of primary heat transport pumps

    International Nuclear Information System (INIS)

    Currie, T.C.

    1986-06-01

    This report analyzes data obtained in two-phase flow tests of primary heat transport pumps performed during the period 1980-1983. Phenomena which have been known to cause pump-induced flow oscillations in pressurized piping systems under two-phase conditions are reviewed and the data analyzed to determine whether any of the identified phenomena could have been responsible for the instabilities observed in those tests. Tentative explanations for the most severe instabilities are given based on those analyses. It is shown that suction pipe geometry probably plays an important role in promoting instabilities, so additional experiments to investigate the effect of suction pipe geometry on the stability of flow in a closed pipe loop under two-phase conditions are recommended

  5. An Experimental Study of Cavitation Detection in a Centrifugal Pump Using Envelope Analysis

    Science.gov (United States)

    Tan, Chek Zin; Leong, M. Salman

    Cavitation represents one of the most common faults in pumps and could potentially lead to a series of failure in mechanical seal, impeller, bearing, shaft, motor, etc. In this work, an experimental rig was setup to investigate cavitation detection using vibration envelope analysis method, and measured parameters included sound, pressure and flow rate for feasibility of cavitation detection. The experiment testing included 3 operating points of the centrifugal pump (B.E.P, 90% of B.E.P and 80% of B.E.P). Suction pressure of the centrifugal pump was decreased gradually until the inception point of cavitation. Vibration measurements were undertaken at various locations including casing, bearing, suction and discharge flange of the centrifugal pump. Comparisons of envelope spectrums under cavitating and non-cavitating conditions were presented. Envelope analysis was proven useful in detecting cavitation over the 3 testing conditions. During the normal operating condition, vibration peak synchronous to rotational speed was more pronounced. It was however during cavitation condition, the half order sub-harmonic vibration component was clearly evident in the envelope spectrums undertaken at all measurement locations except at the pump bearing. The possible explanation of the strong sub-harmonic (½ of BPF) during cavitation existence in the centrifugal pump was due to insufficient time for the bubbles to collapse completely before the end of the single cycle.

  6. An experimental investigation of pump as turbine for micro hydro application

    International Nuclear Information System (INIS)

    Raman, N; Hussein, I; Palanisamy, K; Foo, B

    2013-01-01

    This paper presents the results of an experimental investigation of a centrifugal pump working as turbine (PAT). An end suction centrifugal pump was tested in turbine mode at PAT experimental rig installed in the Mechanical Engineering Laboratory of Universiti Tenaga Nasional. The pump with specific speed of 15.36 (m, m 3 /s) was used in the experiment and the performance characteristic of the PAT was determined. The experiment showed that a centrifugal pump can satisfactorily be operated as turbine without any mechanical problems. As compared to pump operation, the pump was found to operate at higher heads and discharge values in turbine mode. The best efficiency point (BEP) in turbine mode was found to be lower than BEP in pump mode. The results obtained were also compared to the work of some previous researchers.

  7. Place Atrium to Water Seal (PAWS): Assessing Wall Suction Versus No Suction for Chest Tubes After Open Heart Surgery.

    Science.gov (United States)

    Kruse, Tamara; Wahl, Sharon; Guthrie, Patricia Finch; Sendelbach, Sue

    2017-08-01

    Traditionally chest tubes are set to -20 cm H 2 O wall suctioning until removal to facilitate drainage of blood, fluid, and air from the pleural or mediastinal space in patients after open heart surgery. However, no clear evidence supports using wall suction in these patients. Some studies in patients after pulmonary surgery indicate that using chest tubes with a water seal is safer, because this practice decreases duration of chest tube placement and eliminates air leaks. To show that changing chest tubes to a water seal after 12 hours of wall suction (intervention) is a safe alternative to using chest tubes with wall suction until removal of the tubes (usual care) in patients after open heart surgery. A before-and-after quality improvement design was used to evaluate the differences between the 2 chest tube management approaches in chest tube complications, output, and duration of placement. A total of 48 patients received the intervention; 52 received usual care. The 2 groups (intervention vs usual care) did not differ significantly in complications (0 vs 2 events; P = .23), chest tube output (H 1 = 0.001, P = .97), or duration of placement (median, 47 hours for both groups). Changing chest tubes from wall suction to water seal after 12 hours of wall suction is a safe alternative to using wall suctioning until removal of the tubes. ©2017 American Association of Critical-Care Nurses.

  8. Flow in a Low Specific Speed Centrifugal Pump Using PIV

    Directory of Open Access Journals (Sweden)

    Cui Dai

    2013-01-01

    Full Text Available The interflow plays important roles in centrifugal pump design. In order to study the effect of rotation and z-axis on internal flow, two-dimensional particle image velocimetry (PIV measurements have been performed to measure the steady velocity field on three planes in all impeller passages of a low specific-speed centrifugal pump. The results show that the relative velocity flows in blade passages are obviously different in terms of the positions of the blade relative to the tongue. The interaction between the impeller and tongue changes the occurrence and development of low velocity region with time. From shroud to hub, the relative velocity gradually increases, and the minimum value moves toward the suction surface. On the midplane, the magnitude increases with increased flow rate from pressure surface to suction surface, while at the shroud and hub, the measured velocity first increases with decreased flow rate from the blade pressure surface to nearly ζ = 0.5 to 0.6.

  9. Design, test and start up of a cleaning system for the moderator tank bottom of Atucha I Nuclear Power Plant

    International Nuclear Information System (INIS)

    Duca, J.; Gerber, O.; Ibero, M.; Riga, N.

    1989-01-01

    In order to perform the cleaning of the moderator tank bottom, during the repair of the Atucha I nuclear power plant (CNA I) failure, the Empresa Nuclear Argentina de Centrales Electricas (ENACE S.A.) designed a system with the following requirements (asked by CNA I): a) To aspirate and retain free solid particles, uranium dioxide pellets and coolant channels isolations (foils) of minor size settled at the moderator tank bottom, being the reactor at middle loop state. b) To allow a radially cleaning up to 1.4 m from the extracted channel. c) To design a lay-out attaining the ALARA dose exposure. The designed system basically consists in: a) Flexible intake for suction: allows the movement inside the moderator tank and provides the adequate speed to raise the particles. b) Filter: retains the aspirated particles, pellets and foils. Its capacity is 1.8 dm 3 and the minimum size of retained particles is 200 m. The ALARA dose exposure concept is attained due to that the filter is located inside the moderator tank. c) Filtering column: contains the filter and allows the entrance of the extraction and exchange tool (for the flexible intake and filter). d) Suction hose: connects the filtering column with the pump. Its flexibility allows its use in any channel maintaining the same positions of the discharge pump and the return piping. e) Discharge pump: it is a canned centrifugal pump with low-low net positive suction head. f) Return piping: discharges the filtered water into the moderator tank. The system fulfilled satisfactorily all requirements during its operation. (Author)

  10. Suction caissons subjected to monotonic combined loading

    OpenAIRE

    Penzes, P.; Jensen, M.R.; Zania, Varvara

    2016-01-01

    Suction caissons are being increasingly used as offshore foundation solutions in shallow and intermediate water depths. The convenient installation method through the application of suction has rendered this type of foundation as an attractive alternative to the more traditional monopile foundation for offshore wind turbines. The combined loading imposed typically to a suction caisson has led to the estimation of their bearing capacity by means of 3D failure envelopes. This study aims to anal...

  11. Switch loop flexibility affects substrate transport of the AcrB efflux pump

    International Nuclear Information System (INIS)

    Muller, Reinke T.; Travers, Timothy; Cha, Hi-jea; Phillips, Joshua L.

    2017-01-01

    The functionally important switch-loop of the trimeric multidrug transporter AcrB separates the access and deep drug binding pockets in every protomer. This loop, comprising 11 amino acid residues, has been shown to be crucial for substrate transport, as drugs have to travel past the loop to reach the deep binding pocket and from there are transported outside the cell via the connected AcrA and TolC channels. It contains four symmetrically arranged glycine residues suggesting that flexibility is a key feature for pump activity. Upon combinatorial substitution of these glycine residues to proline, functional and structural asymmetry was observed. Proline substitutions on the PC1 proximal side completely abolished transport and reduced backbone flexibility of the switch loop, which adopted a conformation restricting the pathway towards the deep binding pocket. Here, two phenylalanine residues located adjacent to the substitution sensitive glycine residues play a role in blocking the pathway upon rigidification of the loop, since the removal of the phenyl rings from the rigid loop restores drug transport activity.

  12. Vertical pump assembly

    International Nuclear Information System (INIS)

    Dohnal, M.; Rosel, J.; Skarka, V.

    1988-01-01

    The mounting is described of the drive assembly of a vertical pump for nuclear power plants in areas with seismic risk. The assembly is attached to the building floor using flexible and damping elements. The design allows producing seismically resistant pumps without major design changes in the existing types of vertical pumps. (E.S.). 1 fig

  13. Right atrium positioning for exposure of right pulmonary veins during off-pump atrial fibrillation ablation.

    Science.gov (United States)

    Suwalski, Grzegorz; Emery, Robert; Mróz, Jakub; Kaczejko, Kamil; Gryszko, Leszek; Cwetsch, Andrzej; Skrobowski, Andrzej

    2017-06-01

    Concomitant surgical ablation of atrial fibrillation (AF) is recommended for patients undergoing off-pump coronary revascularization in the presence of this arrhythmia. Achievement of optimal visualization of pulmonary veins while maintaining stable haemodynamic conditions is crucial for proper completion of the ablation procedure. This study evaluates the safety and feasibility of right atrial positioning using a suction-based cardiac positioner as opposed to compressive manoeuvres for exposure during off-pump surgical ablation for AF. Thirty-four consecutive patients underwent pulmonary vein isolation, ganglionated plexi ablation and left atrial appendage occlusion during off-pump coronary artery bypass grafting. Right atrial suction positioning was used to visualize right pulmonary veins. Safety and feasibility end points were analysed intraoperatively and in the early postoperative course. In all patients, right atrial positioning created optimal conditions to complete transverse and oblique sinus blunt dissection, correct placement of a bipolar ablation probe, detection and ablation of ganglionated plexi and conduction block assessment. In all patients, this entire right-sided ablation procedure was completed with a single exposure manoeuvre. Feasibility end points were achieved in all study patients. This report documents the safety and feasibility of right atrial exposure using a suction-based cardiac positioner to complete ablation for AF concomitant with off-pump coronary revascularization. This technique may be widely adopted to create stable haemodynamic conditions and optimal visualization of the right pulmonary veins. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  14. The impact analysis of the connecting pipe length and diameter on the operation of a piston hybrid power machine of positive displacement with gas suction capacity

    Science.gov (United States)

    Shcherba, V. E.; Grigoriev, A. V.; Averyanov, G. S.; Surikov, V. I.; Vedruchenko, V. P.; Galdin, N. S.; Trukhanova, D. A.

    2017-08-01

    The article analyzes the impact of the connecting liquid pipe length and diameter on consumables and power characteristics of the piston hybrid power machine with gas suction capacity. The following operating characteristics of the machine were constructed and analyzed: the average height of the liquid column in the jacket space; instantaneous velocity and height of the liquid column in the jacket space; the relative height of the liquid column in the jacket space; volumetric efficiency; indicator isothermal efficiency; flowrate in the pump section; relative pressure losses during suction; relative flowrate. The dependence of the instantaneous pressure in the work space and the suction space of the compressor section on the rotation angle of the crankshaft is determined for different values of the length and diameter of the connecting pipeline.

  15. CFD results for temperature dependence water cooling pump NPSH calculations - 15425

    International Nuclear Information System (INIS)

    Strongin, M.P.

    2015-01-01

    In this work the possibility to model the pump for water cooling reactors behavior in the critical situation was considered for cases when water temperature suddenly increases. In cases like this, cavitation effects may cause pump shutoff and consequently stop the reactor cooling. Centrifugal pump was modeled. The calculations demonstrate strong dependence of NPSH (net-positive-suction-head) on the water temperature on the pump inlet. The water temperature on the inlet lies between 25 and 180 C. degrees. The pump head performance curve has a step-like slope below NPSH point. Therefore, if the pressure on the pump inlet is below than NPSH, it leads to the pump shutoff. For high water temperature on the pump inlet, NPSH follows the vapor saturated pressure for given temperature with some offset. The results clearly show that in case of accidental increase of temperature in the cooling loop, special measures are needed to support the pressure on the pump inlet to prevent pump shutoff. (author)

  16. Preliminary study of efficacy of cup suction in the correction of typical pectus excavatum.

    Science.gov (United States)

    Lopez, Manuel; Patoir, Arnaud; Costes, Frederic; Varlet, François; Barthelemy, Jean-Claude; Tiffet, Olivier

    2016-01-01

    duration of 9 months (2-22). Treatment using cup suction is a promising useful alternative in selected cases of symmetric and asymmetric PE, providing that the thorax is flexible. Treatment duration is directly linked to age, severity and the frequency of use. It is becoming a well-recognized therapy, which improves the self-image of those patients whose anterior chest wall is still pliable. The cup suction can be used for pediatrics and young adults waiting for a treatment, possibly surgery, however, the long-term effect of this procedure remains unclear. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Study on transient hydrodynamic performance and cavitation characteristic of high-speed mixed-flow pump

    International Nuclear Information System (INIS)

    Chen, T; Liu, Y L; Sun, Y B; Wang, L Q; Wu, D Z

    2013-01-01

    In order to analyse the hydrodynamic performance and cavitation characteristic of a high-speed mixed-flow pump during transient operations, experimental studies were carried out. The transient hydrodynamic performance and cavitation characteristics of the mixed-flow pump with guide vane during start-up operation processes were tested on the pump performance test-bed. Performance tests of the pump were carried out under various inlet pressures and speed-changing operations. The real-time instantaneous external characteristics such as rotational speed, hydraulic head, flow rate, suction pressure and discharge pressure of the pump were measured. Based on the experimental results, the effect of fluid acceleration on the hydrodynamic performances and cavitation characteristics of the mixed-flow pump were analysed and evaluated

  18. The effect of balance holes to centrifugal pump performance

    Science.gov (United States)

    Babayigit, O.; Ozgoren, M.; Aksoy, M. H.; Kocaaslan, O.

    2017-07-01

    The aim of this study is to analyze of a centrifugal pump with and without balance holes by using ANSYS-Fluent software. The pump used in the study is a commercial centrifugal pump consisting of two stages that is a model of Sempa Pump Company. Firstly, models of impeller, diffuser, suction and discharge sections of the centrifugal pump were separately drawn using Ansys and Solidworks software. Later, grid structures were generated on the flow volume of the pump. Turbulent flow volume was numerically solved by realizable k-є turbulence model. The flow analyses were focused on the centrifugal pump performance and the flow characteristics under different operational conditions with/without balance holes. Distributions of flow characteristics such as velocity and pressure distributions in the flow volume were also determined, numerically. The results of Computational Fluid Dynamics (CFD) with/without balance holes for the pump head and hydraulic efficiency on the design flow rate of 80 m3/h were found to be 81.5/91.3 m and 51.9/65.3%, respectively.

  19. Improvements in or relating to pumps

    Energy Technology Data Exchange (ETDEWEB)

    Strong, R E; Boyle, K

    1976-06-30

    A pump is described that has what is termed a fluid diode in the inlet and outlet. Each such diode has non-moving parts and is operable to allow fluid to flow therethrough easily in one direction and to give restricted flow in the reverse direction. A suction leg is provided, connected to an ejector having a passage for compressed gas, and a valve is provided in the passage downstream of the ejector operable to open and close the passage periodically, thereby creating alternate negative and positive pumping pressures within the pump chamber. The valve may take the form of a solenoid valve and may include electrically linked means for sensing liquid levels. The pump is stated to be particularly attractive for plants in which it is desirable to avoid pump maintenance. Examples of its application includes the transfer of toxic and radioactive liquids. The exhaust from the ejector can be fed into a containment vessel from which it can be extracted through a normal venting system for plant handling such materials. It is also suitable for sludge pumping. The solenoid valve does not come into contact with the fluid being pumped, and can be located so that it is accessible for maintenance. Stainless steel is normally a convenient constructional material.

  20. Sudden venting test of an emergency bearing for the magnet bearing type compound molecular pump

    International Nuclear Information System (INIS)

    Hiroki, Seiji; Abe, Tetsuya; Murakami, Yoshio; Okamoto, Masatomo; Iguchi, Masashi; Nakamura, Jyunichi; Nakazeki, Tsugito.

    1995-01-01

    The vacuum evacuation system for nuclear fusion reactors bears the role of exhausting hydrogen isotopes in large quantity together with helium continuously for long hours, and as the high vacuum pumps for this purpose, the mechanical pumps which can do continuous evacuation and decrease the quantity of staying radioactive tritium, such as turbo molecular pumps and compound molecular pumps, are promising. Because of the compatibility with tritium, oil lubrication is not desirable, accordingly, the pumps with ceramic rotating vanes and magnetic bearings are demanded. As a part of the development of a magnetic bearing type mechanical pump which can be used for nuclear fusion reactors, the compound molecular pump, in which emergency bearings were incorporated, was made for trial, and the test of sudden air intrusion was carried out, as the results, various knowledges were obtained. The constitution of the testing setup, and the test results are reported. When air was injected at the pressure rise of 3.3x10 4 Pa/s from exhaust port side, after about 2.5 s, the maximum lift of 4.2x10 3 N arose. When air was injected at the pressure rise of 2.7x10 5 Pa/s from the suction part side, after about 0.4s, the maximum lift of 6.9x10 3 N arose. In the air injection alternately from the suction port and exhaust port sides, the emergency bearings functioned normally in 10 times of the test. (K.I.)

  1. Equipment for checking bearing tolerances in sealed pumps, especially for nuclear engineering

    International Nuclear Information System (INIS)

    Zajic, V.

    1980-01-01

    The equipment consists of a guide pin passing through a coaxial telescopic insert mounted in a support nut for connection to the pump suction branch. The guide pin is fitted with a shoulder engaging with the pump flywheel and comprises a pin for exerting torsional, pitching and sliding motion. The support nut is provided with two guide surfaces (on the front face and on the circumference). A third guide surface is on the guide pin face. (H.S.)

  2. Boundary layer on a flat plate with suction

    International Nuclear Information System (INIS)

    Favre, A.; Dumas, R.; Verollet, E.

    1961-01-01

    This research done in wind tunnel concerns the turbulent boundary layer of a porous flat plate with suction. The porous wall is 1 m long and begins 1 m downstream of the leading edge. The Reynolds number based on the boundary layer thickness is of the order of 16.300. The suction rate defined as the ratio of the velocity perpendicular to the wall to the external flow velocity ranges from 0 to 2 per cent. The pressure gradient can be controlled. The mean velocity profiles have been determined for various positions and suction rates by means of total pressure probes together with the intensities of the turbulent velocity fluctuations components, energy spectra and correlations by means of hot wire anemometers, spectral analyser and correlator. The stream lines, the values of the viscous and turbulent shear stresses, of the local wall friction, of the turbulent energy production term, with some information on the dissipation of the energy have been derived from these measurements. For these data the integral of equation of continuity in boundary layer have been drawn. The suction effects on the boundary layer are important. The suction thoroughly alters the mean velocity profiles by increasing the viscous shear stresses near the wall and decreasing them far from the wall, it diminishes the longitudinal and transversal turbulence intensities, the turbulent shear stresses, and the production of energy of turbulence. These effects are much stressed in the inner part of the boundary layer. On the other hand the energy spectra show that the turbulence scale is little modified, the boundary layer thickness being not much diminished by the suction. The suction effects can be appreciated by comparing twice the suction rate to the wall friction coefficient (assumed airtight), quite noticeable as soon as the rate is about unity, they become very important when it reaches ten. (author) [fr

  3. Test specification for decant pump and winch assembly. Revision 2

    International Nuclear Information System (INIS)

    Staehr, T.W.

    1995-01-01

    This specification provides the requirements for testing of the vertical turbine decant pump including the floating suction with load sensing winch control, instrumentation and the associated PLC/PC control system. All assembly necessary for testing including piping, temporary wiring, etc., shall be performed by the Seller. All referenced figures are at the back of this document. The testing consists of performance testing, winch testing and calibration, instrumentation verification testing and run-in testing of the pump. Testing shall be done in the presence and under the direction of the Buyer in accordance with this procedure

  4. Characteristics of electrostatic gas micro-pump with integrated polyimide passive valves

    International Nuclear Information System (INIS)

    Han, Jeahyeong; Yeom, Junghoon; Mensing, Glennys; Flachsbart, Bruce; Shannon, Mark A

    2012-01-01

    We report on the fabrication and characterization of electrostatic gas micro-pumps integrated with polyimide check valves. Touch-mode capacitance actuation, enabled by a fixed silicon electrode and a metal/polyimide diaphragm, creates the suction and push-out of the ambient gas; the gas flow is rectified by the check valves located at the inlet and outlet of the pump. The fabricated pumps were tested with various actuation voltages at different frequencies and duty cycles; an emphasis was placed on investigating the effect of valve flow conductance on the gas pumping characteristics. The pump with higher valve conductance could increase the operating frequency of the pump and affect the pumping characteristics from a pulsating flow to a continuous flow, leading to a higher gas flow rate. This electrostatic pump has a flow control resolution of 1 µL min −1 ; it could generate a gas flow up to 106 µL min −1 . (paper)

  5. Overcoming the problem of residual microbial contamination in dental suction units left by conventional disinfection using novel single component suction handpieces in combination with automated flood disinfection.

    Science.gov (United States)

    Boyle, M A; O'Donnell, M J; Russell, R J; Galvin, N; Swan, J; Coleman, D C

    2015-10-01

    Decontaminating dental chair unit (DCU) suction systems in a convenient, safe and effective manner is problematic. This study aimed to identify and quantify the extent of the problems using 25 DCUs, methodically eliminate these problems and develop an efficient approach for reliable, effective, automated disinfection. DCU suction system residual contamination by environmental and human-derived bacteria was evaluated by microbiological culture following standard aspiration disinfection with a quaternary ammonium disinfectant or alternatively, a novel flooding approach to disinfection. Disinfection of multicomponent suction handpieces, assembled and disassembled, was also studied. A prototype manual and a novel automated Suction Tube Cleaning System (STCS) were developed and tested, as were novel single component suction handpieces. Standard aspiration disinfection consistently failed to decontaminate DCU suction systems effectively. Semi-confluent bacterial growth (101-500 colony forming units (CFU) per culture plate) was recovered from up to 60% of suction filter housings and from up to 19% of high and 37% of low volume suction hoses. Manual and automated flood disinfection of DCU suction systems reduced this dramatically (ranges for filter cage and high and low volume hoses of 0-22, 0-16 and 0-14CFU/plate, respectively) (P<0.0001). Multicomponent suction handpieces could not be adequately disinfected without prior removal and disassembly. Novel single component handpieces, allowed their effective disinfection in situ using the STCS, which virtually eliminated contamination from the entire suction system. Flood disinfection of DCU suction systems and single component handpieces radically improves disinfection efficacy and considerably reduces potential cross-infection and cross-contamination risks. DCU suction systems become heavily contaminated during use. Conventional disinfection does not adequately control this. Furthermore, multicomponent suction handpieces

  6. Heat pump system with selective space cooling

    Science.gov (United States)

    Pendergrass, J.C.

    1997-05-13

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

  7. End-tidal carbon dioxide monitoring during flexible fiberoptic ...

    African Journals Online (AJOL)

    In recent years, flexible fiberoptic bronchoscopy (FFB) has been applied for diagnostic and some therapeutic purposes. During FFB and even in the presence of supplemental oxygen, hypoventilation leading to hypoxia and desaturation may occur; this is aggravated by the use of suction. Arterial oxygen saturation is usually ...

  8. Suction power output and the inertial cost of rotating the neurocranium to generate suction in fish.

    Science.gov (United States)

    Van Wassenbergh, Sam; Day, Steven W; Hernández, L Patricia; Higham, Timothy E; Skorczewski, Tyler

    2015-05-07

    To expand the buccal cavity, many suction-feeding fishes rely on a considerable contribution from dorsal rotation of the dorsal part of the head including the brains, eyes, and several bones forming the braincase and skull roof (jointly referred to as the neurocranium). As the neurocranium takes up a large part of the total mass of the head, this rotation may incur a considerable inertial cost. If so, this would suggest a significant selective pressure on the kinematics and mass distribution of the neurocranium of suction feeders. Here, an inverse dynamic model is formulated to calculate the instantaneous power required to rotate the neurocranium, approximated by a quarter ellipsoid volume of homogeneous density, as well as to calculate the instantaneous suction power based on intra-oral pressure and head volume quantifications. We applied this model to largemouth bass (Micropterus salmoides) and found that the power required to rotate the neurocranium accounts for only about 4% of the power required to suck water into the mouth. Furthermore, recovery of kinetic energy from the rotating neurocranium converted into suction work may be possible during the phase of neurocranial deceleration. Thus, we suggest that only a negligible proportion of the power output of the feeding muscles is lost as inertial costs in the largemouth bass. Consequently, the feeding performance of piscivorous suction feeders with generalised morphology, comparable to our model species, is not limited by neurocranial motion during head expansion. This suggests that it is thus not likely to be a factor of importance in the evolution of cranial shape and size. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Suction v. conventional curettage in incomplete abortion

    African Journals Online (AJOL)

    Suction v. conventional curettage in incomplete abortion. A randomised controlled trial. D. A. A. VERKUYL, C. A. CROWTHER .Abstract This randomised controlled trial of 357 patients who had had an incomplete abortion compared suction curettage with conventional curettage for evacuation ofthe uterus. The 179 patients ...

  10. Dielectric elastomer actuators for octopus inspired suction cups.

    Science.gov (United States)

    Follador, M; Tramacere, F; Mazzolai, B

    2014-09-25

    Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms.

  11. Dielectric elastomer actuators for octopus inspired suction cups

    International Nuclear Information System (INIS)

    Follador, M; Tramacere, F; Mazzolai, B

    2014-01-01

    Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms. (paper)

  12. Does the suction drain diameter matter? Bleeding analysis after total knee replacement comparing different suction drain gauges

    Directory of Open Access Journals (Sweden)

    Marcos George de Souza Leao

    Full Text Available ABSTRACT OBJECTIVES: To evaluate bleeding and the estimated blood loss in patients who underwent total knee replacement (TKR with different closed suction drains (3.2-mm and 4.8-mm gauge. METHODS: This was a randomized controlled trial with 22 patients who underwent TKR and were divided into two groups: Group I, with 11 patients in whom the 3.2-mm suction drain was used, and Group II, with 11 patients in whom the 4.8-mm suction drain was used. The hematocrit was measured after 24, 48 and 72 h after surgery in order to calculate the estimated blood loss. The drained volume was measured 3, 6, 12, 24, and 48 h after TKR, and thereafter both groups were compared. RESULTS: Regarding the hematocrit, there were no differences between groups in measured periods (24, 48, and 72 h after surgery. The total bleeding measured at the suction drains within 48 h was higher in Group II, with a statistically significant difference (p = 0.005; in the first 24 h, there was major bleeding in Group II (mean 893 mL, with a significant difference (p = 0.004. Between 24 and 48 h, there was no statistically significant difference in both groups (p = 0.710. The total estimated bleeding was higher in Group I, with mean of 463 mL, versus 409 mL in Group II, with no statistical significance (p = 0.394. CONCLUSIONS: Bleeding was higher in the group that used the 4.8 mm gauge suction drain, with no differences in hematocrit and estimated blood loss.

  13. Relative effectiveness of insulin pump treatment over multiple daily injections and structured education during flexible intensive insulin treatment for type 1 diabetes: cluster randomised trial (REPOSE).

    Science.gov (United States)

    2017-03-30

    Objective  To compare the effectiveness of insulin pumps with multiple daily injections for adults with type 1 diabetes, with both groups receiving equivalent training in flexible insulin treatment. Design  Pragmatic, multicentre, open label, parallel group, cluster randomised controlled trial (Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE) trial). Setting  Eight secondary care centres in England and Scotland. Participants  Adults with type 1 diabetes who were willing to undertake intensive insulin treatment, with no preference for pumps or multiple daily injections. Participants were allocated a place on established group training courses that taught flexible intensive insulin treatment ("dose adjustment for normal eating," DAFNE). The course groups (the clusters) were then randomly allocated in pairs to either pump or multiple daily injections. Interventions  Participants attended training in flexible insulin treatment (using insulin analogues) structured around the use of pump or injections, followed for two years. Main outcome measures  The primary outcomes were a change in glycated haemoglobin (HbA1c) values (%) at two years in participants with baseline HbA1c value of ≥7.5% (58 mmol/mol), and the proportion of participants achieving an HbA1c value of intention to treat analysis, of which 235 (119 pump and 116 injection) had baseline HbA1c values of ≥7.5%. Glycaemic control and rates of severe hypoglycaemia improved in both groups. The mean change in HbA1c at two years was -0.85% with pump treatment and -0.42% with multiple daily injections. Adjusting for course, centre, age, sex, and accounting for missing values, the difference was -0.24% (-2.7 mmol/mol) in favour of pump users (95% confidence interval -0.53 to 0.05, P=0.10). Most psychosocial measures showed no difference, but pump users showed greater improvement in treatment satisfaction and some quality of life domains (dietary freedom and daily hassle) at 12 and 24

  14. Bottom Feeding and Beyond: How the Premaxillary Protrusion of Cypriniforms Allowed for a Novel Kind of Suction Feeding.

    Science.gov (United States)

    Hernandez, L Patricia; Staab, Katie Lynn

    2015-07-01

    While much of the functional work on suction feeding has involved members of Acanthopterygii, an earlier cypriniform radiation led to over 3200 species filling nearly every freshwater trophic niche. Within the great majority of acanthomorph clades that have been investigated suction feeding and the underlying morphology responsible for the generation of rapid suction have been largely conserved. This conserved feeding-apparatus is often associated with increasing the force experienced by the prey item, thus making a strike on elusive prey more effective. Cypriniforms' trophic anatomy is comprised of a number of novelties used for benthic feeding, which characterized early members of this clade. The modified cypriniform structure of the oral jaws represents a situation in which a particular type of suction feeding allowed for probing the benthos with a more functionally maneuverable anatomy. Requisite evolutionary modifications included origin and elongation of a median kinethmoid, duplications of certain divisions of the muscles of the adductor mandibulae, and origin of a dorsal, intra-buccal muscular palatal organ used in winnowing detritus. The elongated kinethmoid (coupled with modified adductor muscles) allowed for a type of premaxillary protrusion that decoupled the upper and lower jaws, enabled premaxillary protrusions with a closed mouth, and facilitated benthic feeding by increasing functional flexibility. The resultant flow of fluid generated by cypriniforms is also quite flexible, with multiple instances of peak flow in a single feeding event. This greatly modified morphology allowed for a degree of kinematic maneuverability not seen within most acanthomorphs. Later cypriniform radiations into piscivorous, insectivorous, or planktivorous feeding guilds were associated with shortening of the kinethmoid and with simplified morphology of the adductor, likely involving an emphasis on ram feeding. Although this suite of morphological novelties seemingly

  15. Evaluation of a flexible bronchoscope prototype designed for bronchoscopy during mechanical ventilation: a proof-of-concept study.

    Science.gov (United States)

    Nay, M-A; Auvet, A; Mankikian, J; Herve, V; Dequin, P-F; Guillon, A

    2017-06-01

    Bronchoscopy during mechanical ventilation of patients' lungs significantly affects ventilation because of partial obstruction of the tracheal tube, and may thus be omitted in the most severely ill patients. It has not previously been possible to reduce the external diameter of the bronchoscope without reducing the diameter of the suction channel, thus reducing the suctioning capacity of the device. We believed that a better-designed bronchoscope could improve the safety of bronchoscopy in patients whose lungs were ventilated. We designed a flexible bronchoscope prototype with a drumstick-shaped head consisting of a long, thin proximal portion; a short and large distal portion for camera docking; and a large suction channel throughout the length of the device. The aims of our study were to test the impact of our prototype on mechanical ventilation when inserted into the tracheal tube, and to assess suctioning capacity. We first tested the efficiency of the suction channel, and demonstrated that the suction flow of the prototype was similar to that of conventional adult bronchoscopes. We next evaluated the consequences of bronchoscopy when using the prototype on minute ventilation and intrathoracic pressures during mechanical ventilation: firstly, in vitro using a breathing simulator; and secondly, in vivo using a porcine model of pulmonary ventilation. The insertion of adult bronchoscopes into the tracheal tube immediately impaired the protective ventilation strategy employed, whereas the prototype preserved it. For the first time, we have developed an innovative flexible bronchoscope designed for bronchoscopy during invasive mechanical ventilation, that both preserved the protective ventilation strategy, and enabled efficient suction flow. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

  16. Numerical and Experimental Study of Pump Sump Flows

    Directory of Open Access Journals (Sweden)

    Wei-Liang Chuang

    2014-01-01

    Full Text Available The present study analyzes pump sump flows with various discharges and gate submergence. Investigations using a three-dimensional large eddy simulation model and an acoustic Doppler velocimeter are performed. Flow patterns and velocity profiles in the approaching flow are shown to describe the flow features caused by various discharges and gate submergence. The variation of a large-scale spanwise vortex behind a sluice gate is examined and discussed. The suction effect on approaching flow near the pipe column is examined using numerical modeling. To gain more understanding of the vortices variation, a comparison between time-averaged and instantaneous flow patterns is numerically conducted. Additionally, swirl angle, a widely used index for evaluating pump efficiency, is experimentally and numerically examined under various flow conditions. The results indicate that the pump becomes less efficient with increasing discharge and gate submergence. The fluctuation of the free surface over the pump sump is also discussed.

  17. Comparison of different lubricating oil pump systems for combustion engines. Vergleich verschiedener Schmieroelpumpen-Systeme bei Verbrennungsmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, S; Haerle, C; Schreiber, B

    1994-10-01

    The present day and future legislative requirements with regard to fuel consumption and improvement of emission values are forcing the automotive industry to continually improve its technology. However, the investments made in such technical innovations should be set-off by the results. The lubricating oil pump can make an important contribution with optimum design and through the choice of the most adequate pump system. Over the last 17 years, SHW has worked very closely with the automotive industry on the development of lubricating oil pumps. One of the results of this research work is a Suction Regulated Pump (SRP) which distinguishes itself from conventional pumps through its lower drive power. We will proceed to explain this pump system, comparing it with the present day pump systems. (orig.)

  18. Advances on development of suction and temperature controlled oedometer cell

    International Nuclear Information System (INIS)

    Ye Weimin; Zhang Yawei; Chen Bao; Wang Min

    2010-01-01

    Oedometer cells for unsaturated soils can be classified into two types, that is, conventional unsaturated oedometer cells (high-suction unsaturated oedometer cell, high-suction and high-pressure unsaturated oedometer cell) and temperature controlled unsaturated oedometer cells. Among them, the osmotic, vapor equilibrium and axis translation techniques are often employed for suction control. The thermostat bath method and thermostatically controlled heater method are commonly used for temperature control. The lever loading system, hydraulic loading system and air pressure loading system are commonly means used for vertical pressure. Combination of osmotic (or axis translation) technique with vapor equilibrium method employed for the full range suction control, thermostatically liquid temperature control method, and the hydraulic loading system, could be used for suction, temperature and loading control in the design for unsaturated oedometer cells in the future, which can be used for study of buffer/backfill materials under high-temperature, high pressure and full range suction conditions. (authors)

  19. Dynamic behaviour of suction caissons

    Energy Technology Data Exchange (ETDEWEB)

    Liingaard, M.

    2006-12-15

    Offshore wind energy is a promising source of energy in the near future, and is rapidly becoming competitive with other power generating technologies. The continuous improvement in wind turbine technology means that the wind turbines have increased tremendously in both size and performance during the last 25 years. In order to reduce the costs, the overall weight of the wind turbine components is minimized, which means that the wind turbine structures become more flexible and thus more sensitive to dynamic excitation. Since the first resonance frequency of the modern offshore wind turbines is close to the excitation frequencies of the rotor system, it is of outmost importance to be able to evaluate the resonance frequencies of the wind turbine structure accurately as the wind turbines increase in size. In order to achieve reliable responses of the wind turbine structure during working loads it is necessary to account for the possibilities of dynamic effects of the soil-structure interaction. The aim of this thesis is to evaluate the dynamic soil-structure interaction of foundations for offshore wind turbines, with the intention that the dynamic properties of the foundation can be properly included in a composite structure-foundation system. The work has been focused on one particular foundation type; the suction caisson. The frequency dependent stiffness (impedance) of the suction caisson has been investigated by means of a three-dimensional coupled Boundary Element/Finite Element model, where the soil is simplified as a homogenous linear viscoelastic material. The dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequencydependent coefficients corresponding to the different degrees of freedom. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been carried out for different combinations of the

  20. Dynamic Behaviour of Suction Caissons

    DEFF Research Database (Denmark)

    Liingaard, Morten

    to the excitation frequencies of the rotor system, it is of outmost importance to be able to evaluate the resonance frequencies of the wind turbine structure accurately as the wind turbines increase in size. In order to achieve reliable responses of the wind turbine structure during working loads it is necessary...... in a composite structure-foundation system. The work has been focused on one particular foundation type; the suction caisson. The frequency dependent stiffness (impedance) of the suction caisson has been investigated by means of a three-dimensional coupled Boundary Element/Finite Element model, where the soil...

  1. Investigation of suction anchor pullout capacity under undrained conditions

    OpenAIRE

    Jarand, Pollestad

    2015-01-01

    Master's thesis in Offshore technology Floating units are dependent on reliable mooring systems to ensure safety during marine operations. Suction anchors have proved to be a technologically viable and cost-effective concept. They are capable of precision installation, re-use, and provide large resistive capacity. This thesis investigates load capacity and failure modes of suction anchors subjected to vertical, horizontal (lateral), and incline loading. Suction anchor design co...

  2. Enhanced effect of suction-cavitation on the ozonation of phenol

    International Nuclear Information System (INIS)

    Wu Zhilin; Franke, Marcus; Ondruschka, Bernd; Zhang, Yongchun; Ren Yanze; Braeutigam, Patrick; Wang, Weimin

    2011-01-01

    800 mL of 1.0 mM phenol-containing aqueous solution was circulated at 20 ° C for 30 min in a suction-reactor, while 3.2 mg min -1 ozone was introduced into the solution under the suction orifice. The removal rates of phenol vary polynomially with the orifice diameter as well as the suction pressure. The rate constant for the zero-order kinetics achieves the highest value at -0.070 MPa by using 5 mm orifice. Although the suction-cavitation alone cannot remove phenol in 30 min, it can considerably enhance the ozonation of phenol. The rate constants for the zero-order kinetics by the simple ozonation and the combined method are 0.018 and 0.028 min -1 , respectively. Furthermore, no ozone was observed in the tail gas during the first 15 min for the ozonation in the suction reactor, and then the concentration of unreacted ozone slowly increased, indicating that the utilization rate of ozone is significantly improved by the suction-cavitation. The increasing input concentration of ozone obviously accelerates the ozonation of phenol, but the total required quantities of ozone are very close by various ozone input concentrations to reach the same degradation rate, indicating the ozonation assisted by the suction-cavitation can be considered as a quantitative reaction.

  3. Functional design criteria 241-AP-102 Flexible Receiver System

    International Nuclear Information System (INIS)

    Roblyer, S.P.

    1995-01-01

    A mixer pump was installed in the 1.07 m (42-in.) riser of the central pump pit of tank 241-AP-102 to mitigate potential fluid separation particle sedimentation by mixing the tank's contents. The mixer pump performed this function until failure. Its removal is now necessary to meet possible tank content removal commitments or other corrective actions. The proposed removal procedure requires a flexible receiver that will provide a barrier to contamination during removal and transfer of the pump to the mixer pump storage container. This document describes the functional design criteria of the flexible receiver. These criteria include the functional and performance requirements of the flexible receiver as a barrier to contamination during normal conditions and contingencies and the instrumentation requirements

  4. High-efficiency pump for space helium transfer. Final Technical Report

    International Nuclear Information System (INIS)

    Hasenbein, R.; Izenson, M.G.; Swift, W.L.; Sixsmith, H.

    1991-12-01

    A centrifugal pump was developed for the efficient and reliable transfer of liquid helium in space. The pump can be used to refill cryostats on orbiting satellites which use liquid helium for refrigeration at extremely low temperatures. The pump meets the head and flow requirements of on-orbit helium transfer: a flow rate of 800 L/hr at a head of 128 J/kg. The overall pump efficiency at the design point is 0.45. The design head and flow requirements are met with zero net positive suction head, which is the condition in an orbiting helium supply Dewar. The mass transfer efficiency calculated for a space transfer operation is 0.99. Steel ball bearings are used with gas fiber-reinforced teflon retainers to provide solid lubrication. These bearings have demonstrated the longest life in liquid helium endurance tests under simulated pumping conditions. Technology developed in the project also has application for liquid helium circulation in terrestrial facilities and for transfer of cryogenic rocket propellants in space

  5. The effects of design parameters on vortex diode pump performance, 2

    International Nuclear Information System (INIS)

    Yoshitomi, Hideki; Koizumi, Tadao; Muroyama, Kenichi; Wada, Tsutomu.

    1989-01-01

    A fluidic pump with two vortex diodes is a new technology for transporting dangerous corrosive fluids without the use of moving parts. The pump can be connected with the discharge tank through series and cascade connections. In the previous report, we described the fundamentals and design criteria of the pump for the series connection case. This study has been performed with the same object as the previous work for the case of cascade connection. First, we present the basic pump characteristics with some dimensionless performance factors by analyzing the pump model. Then, the effects of the cylinder volumetric coefficient, driving pressure, suction-diode-to-delivery-diode-passage-area ratio and reverse-flow-to-forward-flow-resistance ratio of the vortex diode are investigated. As a result, the characteristic difference between series and cascade connections is clarified. Basic ways to decide the value of each performance factor are suggested. (author)

  6. Influence of the positive prewhirl on the performance of centrifugal pumps with different airfoils

    International Nuclear Information System (INIS)

    Zhou, C M; Wang, H M; Huang, X; Lin, H

    2012-01-01

    According to the basic theory of turbomachinery design and inlet guide vanes prewhirl regulation, two different airfoils inlet guide vanes of prewhirl regulation device were designed, the influence of the positive prewhirl to the performance of centrifugal pump were studied based on different airfoils. The results show that, for a single-suction centrifugal pump: Gottingen bowed blade-type inlet guide vane adjustment effect is better than straight blade-type inlet guide; appropriate design of positive prewhirl can elevate the efficiency of centrifugal pumps. Compared with no vane conditions, the efficiency of centrifugal pump with prewhirl vanes has been greatly improved and the power consumption has been reduced significantly, while has little influence on the head.

  7. Robotic Hand with Flexible Fingers for Grasping Cylindrical Objects

    OpenAIRE

    柴田, 瑞穂

    2015-01-01

    In this manuscript, a robotic hand for grasping a cylindrical object is proposed. This robotic hand has flexible fingers that can hold a cylindrical object during moving. We introduce a grasping strategy for a cylindrical object in terms of state transition graph. In this strategy the robotic hand picks up the cylindrical object utilizing a suction device before the hand grasp the object. We also design the flexible fingers; then, we investigate the validity of this robotic hand via several e...

  8. On equations for the total suction and its matric and osmotic components

    International Nuclear Information System (INIS)

    Dao, Vinh N.T.; Morris, Peter H.; Dux, Peter F.

    2008-01-01

    A clear fundamental understanding of suctions is crucial for the study of the behaviour of plastic cement mortar and concrete, including plastic shrinkage cracking. In this paper, the expression relating the change in free energy of the pore water with an isothermal change in pressure is first derived. Based upon definitions of suctions, it is then shown that total, matric, and osmotic suctions can all be expressed in the same thermodynamic form. The widely accepted, but not yet satisfactorily validated, assumption that the total suction comprises matric and osmotic components is then confirmed theoretically. The well-known Kelvin equation for matric suction, and Morse and van't Hoff equations for osmotic suction are subsequently derived from the corresponding thermodynamic equations. The applicability of latter two equations in evaluating the osmotic suctions of cement mortar and concrete is highlighted

  9. Suction v. conventional curettage in incomplete abortion A ...

    African Journals Online (AJOL)

    This randomised controlled trial of 357 patients who had had an incomplete abortion compared suction curettage with conventional curettage for evacuation ofthe uterus. The 179 patients undergoing suction curettage had a significantly lower intra-operative blood loss (P < 0,0001) and a significantly higher mean ...

  10. Octopus-like suction cups: from natural to artificial solutions.

    Science.gov (United States)

    Tramacere, F; Follador, M; Pugno, N M; Mazzolai, B

    2015-05-13

    Octopus suckers are able to attach to all nonporous surfaces and generate a very strong attachment force. The well-known attachment features of this animal result from the softness of the sucker tissues and the surface morphology of the portion of the sucker that is in contact with objects or substrates. Unlike artificial suction cups, octopus suckers are characterized by a series of radial grooves that increase the area subjected to pressure reduction during attachment. In this study, we constructed artificial suction cups with different surface geometries and tested their attachment performances using a pull-off setup. First, smooth suction cups were obtained for casting; then, sucker surfaces were engraved with a laser cutter. As expected, for all the tested cases, the engraving treatment enhanced the attachment performance of the elastomeric suction cups compared with that of the smooth versions. Moreover, the results indicated that the surface geometry with the best attachment performance was the geometry most similar to octopus sucker morphology. The results obtained in this work can be utilized to design artificial suction cups with higher wet attachment performance.

  11. The creation and research of the disk-type molecular pump above the top end of centrifuge

    International Nuclear Information System (INIS)

    Li Yunan; Dong Jinping

    2014-01-01

    Disk-type molecular pump placed above the top end of a centrifuge could improve the vacuum of the sleeve, as well as reduce the friction power consumption. This issue carries out a numerical simulation based on the model of molecular pump installed above the top end of centrifuge. The mathematical model is established and calculated by the Matlab program, studying the gas passageways of pump. The suction performance under the influence of gas passageways' geometric dimensions is analyzed, focusing on the effect of different shapes of side walls in the passageway. Design criterion of increasing the compression ratio of disk-type molecular pump is concluded from the analysis. (authors)

  12. Self-optimizing control of air-source heat pump with multivariable extremum seeking

    International Nuclear Information System (INIS)

    Dong, Liujia; Li, Yaoyu; Mu, Baojie; Xiao, Yan

    2015-01-01

    The air-source heat pump (ASHP) is widely adopted for cooling and heating of residential and commercial buildings. The performance of ASHP can be controlled by several operating variables, such as compressor capacity, condenser fan speed, evaporator fan speed and suction superheat. In practice, the system characteristics can be varied significantly by the variations in ambient condition, operation setpoint, internal thermal load and equipment degradation, which makes it difficult to obtain accurate plant models. As consequence, the model based control strategies for ASHP could limit the achievable energy efficiency. Model-free self-optimizing control strategies are thus more preferable. In this study, a multi-input extremum seeking control (ESC) scheme is proposed for both heating and cooling operation of ASHP. The zone temperature is assumed to be regulated by the compressor capacity, while the expansion valve opening is used to regulate the suction superheat at the given setpoint. The total power consumption of the compressor, the condenser fan and the evaporator fan is measured as input to the ESC, while the ESC controls the evaporator fan speed, the condenser fan speed and the suction superheat setpoint. The proposed scheme is evaluated with a Modelica based dynamic simulation model of ASHP under both cooling and heating modes of operation. Simulation results show the effectiveness of the proposed scheme to achieve the maximum achievable efficiency in a nearly model-free manner. - Highlights: • Multi-input ESC. • Air-source heat pump. • Cooling and heating. • Modelica based model

  13. Comparison the Effects of Shallow and Deep Endotracheal Tube Suctioning on Respiratory Rate, Arterial Blood Oxygen Saturation and Number of Suctioning in Patients Hospitalized in the Intensive Care Unit: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Mohammad Abbasinia

    2014-09-01

    Full Text Available Introduction: Endotracheal tube suctioning is essential for improve oxygenation in the patients undergoing mechanical ventilation. There are two types of shallow and deep endotracheal tube suctioning. This study aimed to evaluate the effect of shallow and deep suctioning methods on respiratory rate (RR, arterial blood oxygen saturation (SpO2 and number of suctioning in patients hospitalized in the intensive care units of Al-Zahra Hospital, Isfahan, Iran. Methods: In this randomized controlled trial, 74 patients who hospitalized in the intensive care units of Isfahan Al-Zahra Hospital were randomly allocated to the shallow and deep suctioning groups. RR and SpO2 were measured immediately before, immediately after, 1 and 3 minute after each suctioning. Number of suctioning was also noted in each groups. Data were analyzed using repeated measures analysis of variance (RMANOVA, chi-square and independent t-tests. Results: RR was significantly increased and SpO2 was significantly decreased after each suctioning in the both groups. However, these changes were not significant between the two groups. The numbers of suctioning was significantly higher in the shallow suctioning group than in the deep suctioning group. Conclusion: Shallow and deep suctioning had a similar effect on RR and SpO2. However, shallow suctioning caused further manipulation of patient’s trachea than deep suctioning method. Therefore, it seems that deep endotracheal tube suctioning method can be used to clean the airway with lesser manipulation of the trachea.

  14. Comparison the effects of shallow and deep endotracheal tube suctioning on respiratory rate, arterial blood oxygen saturation and number of suctioning in patients hospitalized in the intensive care unit: a randomized controlled trial.

    Science.gov (United States)

    Abbasinia, Mohammad; Irajpour, Alireza; Babaii, Atye; Shamali, Mehdi; Vahdatnezhad, Jahanbakhsh

    2014-09-01

    Endotracheal tube suctioning is essential for improve oxygenation in the patients undergoing mechanical ventilation. There are two types of shallow and deep endotracheal tube suctioning. This study aimed to evaluate the effect of shallow and deep suctioning methods on respiratory rate (RR), arterial blood oxygen saturation (SpO2) and number of suctioning in patients hospitalized in the intensive care units of Al-Zahra Hospital, Isfahan, Iran. In this randomized controlled trial, 74 patients who hospitalized in the intensive care units of Isfahan Al-Zahra Hospital were randomly allocated to the shallow and deep suctioning groups. RR and SpO2 were measured immediately before, immediately after, 1 and 3 minute after each suctioning. Number of suctioning was also noted in each groups. Data were analyzed using repeated measures analysis of variance (RMANOVA), chi-square and independent t-tests. RR was significantly increased and SpO2 was significantly decreased after each suctioning in the both groups. However, these changes were not significant between the two groups. The numbers of suctioning was significantly higher in the shallow suctioning group than in the deep suctioning group. Conclusion : Shallow and deep suctioning had a similar effect on RR and SpO2. However, shallow suctioning caused further manipulation of patient's trachea than deep suctioning method. Therefore, it seems that deep endotracheal tube suctioning method can be used to clean the airway with lesser manipulation of the trachea.

  15. Apparatus and process for recovering petroleum spread on the surface of water

    Energy Technology Data Exchange (ETDEWEB)

    Sourdis, P

    1968-05-06

    A flexible suction tube is towed by means of 2 or more cables in a direction substantially perpendicular to the axis of the tube. The tube is made of light plastic and has a longitudinal slot over its entire length; the width of the slot can be made adjustable. The interior of the suction tube is connected through tubes with a discharge tube in which the liquid level can vary between certain limits. The discharge tube is equipped with floats and steering surfaces to maintain its position in the water; its ends are connected to the pumps on a ship. This assembly is used in conjunction with a flexible, ballasted barrier filled with air to insure its buoyancy. The barrier may consist of a flat plastic tube, or of sheet plastic wound on a core of foamed or expanded plastic. The barrier is stored aboard a tanker or aboard the pumping ship, and when in use, it is towed by one or several speedboats.

  16. Development of standard practice guidelines for open and closed system suctioning.

    Science.gov (United States)

    Özden, Dilek; Görgülü, R Selma

    2012-05-01

    This study was carried out to determine the knowledge and practice of nurses before and after training and the development of standard practice guidelines for open and closed system suctioning methods in patients with endotracheal tubes. Many life-threatening complications can occur when a suctioning procedure is not performed with the correct technique. It has been reported that standard practice guidelines for suctioning are insufficient in clinical practice. Non-participant structured observational study. We assessed a total of 48 nurses who were employed in the cardiovascular surgery intensive care unit of a state hospital in Turkey. We used a questionnaire and nurse observation forms to assess the use of the open and closed system suctioning. There was a significant difference between the mean scores of the answers ('true', 'wrong' and 'I do not know') for the use of open and closed system suctioning before and after training. In addition, all steps of both suctioning procedures were carried out correctly during the third observation. The compliance of the nurses to the standard practice guidelines for open and closed suctioning and their knowledge levels on the subject were increased after training, while the implementation of standards was satisfactory. The development of open and closed system suctioning standard practice guidelines directly contributed to the enhancement of patient safety and the quality of nursing care. It is suggested that, as in other nursing care practices, suctioning should be carried out in accordance with standard practice guidelines, and health institutions should develop their standard practice guidelines and work in accordance with them. © 2012 Blackwell Publishing Ltd.

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

    International Nuclear Information System (INIS)

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

    1999-01-01

    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

  18. Nuclear reactor with coolant circulation pumps

    International Nuclear Information System (INIS)

    Peck, D.A.; Stolecki, W.E.

    1975-01-01

    Thermally induced movement of a pump or a heat exchanger in the primary circuit of a PWR is made possible by a suspension device. This device must however be, so rigid that it does not yield in cases of emergency. For this purpose, in the case of the pump a lower ring is provided carrying the pump by means of four columns. The columns are flexibly supported on the ring and a fixed constuction. Turned about 90% from these columns, two additional horizontal bars are flexibly mounted on the ring and on the motor housing of the pump as well as on the fixed construction. At the upper end of the motor housing, two shock absorbers are hinged in the same way. The joints are shaped as ball- and socket hinges. (DG) [de

  19. Suction generation in white-spotted bamboo sharks Chiloscyllium plagiosum.

    Science.gov (United States)

    Wilga, Cheryl D; Sanford, Christopher P

    2008-10-01

    After the divergence of chondrichthyans and teleostomes, the structure of the feeding apparatus also diverged leading to alterations in the suction mechanism. In this study we investigated the mechanism for suction generation during feeding in white-spotted bamboo sharks, Chiloscyllium plagiosum and compared it with that in teleosts. The internal movement of cranial elements and pressure in the buccal, hyoid and pharyngeal cavities that are directly responsible for suction generation was quantified using sonomicrometry and pressure transducers. Backward stepwise multiple linear regressions were used to explore the relationship between expansion and pressure, accounting for 60-96% of the variation in pressure among capture events. The progression of anterior to posterior expansion in the buccal, hyoid and pharyngeal cavities is accompanied by the sequential onset of subambient pressure in these cavities as prey is drawn into the mouth. Gape opening triggers the onset of subambient pressure in the oropharyngeal cavities. Peak gape area coincides with peak subambient buccal pressure. Increased velocity of hyoid area expansion is primarily responsible for generating peak subambient pressure in the buccal and hyoid regions. Pharyngeal expansion appears to function as a sink to receive water influx from the mouth, much like that of compensatory suction in bidirectional aquatic feeders. Interestingly, C. plagiosum generates large suction pressures while paradoxically compressing the buccal cavity laterally, delaying the time to peak pressure. This represents a fundamental difference from the mechanism used to generate suction in teleost fishes. Interestingly, pressure in the three cavities peaks in the posterior to anterior direction. The complex shape changes that the buccal cavity undergoes indicate that, as in teleosts, unsteady flow predominates during suction feeding. Several kinematic variables function together, with great variation over long gape cycles to

  20. Massive aspiration past the tracheal tube cuff caused by closed tracheal suction system.

    Science.gov (United States)

    Dave, Mital H; Frotzler, Angela; Madjdpour, Caveh; Koepfer, Nelly; Weiss, Markus

    2011-01-01

    Aspiration past the tracheal tube cuff has been recognized to be a risk factor for the development of ventilator-associated pneumonia (VAP). This study investigated the effect of closed tracheal suctioning on aspiration of fluid past the tracheal tube cuff in an in vitro benchtop model. High-volume low pressure tube cuffs of 7.5 mm internal diameter (ID) were placed in a 22 mm ID artificial trachea connected to a test lung. Positive pressure ventilation (PPV) with 15 cm H₂O peak inspiratory pressure and 5 cm H₂O positive end-expiratory pressure (PEEP) was used. A closed tracheal suction system (CTSS) catheter (size 14Fr) was attached to the tracheal tube and suction was performed for 5, 10, 15, or 20 seconds under 200 or 300 cm H₂O suction pressures. Amount of fluid (mL) aspirated along the tube cuff and the airway pressure changes were recorded for each suction procedure. Fluid aspiration during different suction conditions was compared using Kruskal-Wallis and Mann-Whitney test (Bonferroni correction [α = .01]). During 10, 15, and 20 seconds suction, airway pressure consistently dropped down to -8 to -13 cm H₂O (P aspiration was never observed under PPV + PEEP but occurred always during suctioning. Aspiration along the tube cuff was higher with -300 cm H₂O than with -200 cm H₂O suction pressure (P aspiration of fluid occurs along the tracheal tube cuff during suction with the closed tracheal suction system. © SAGE Publications 2011.

  1. Dynamic stiffness of horizontally vibrating suction caissons

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara; Cisternino, Michele

    2016-01-01

    The promising potential for offshore wind market is on developing wind farms in deeper waters with bigger turbines. In deeper waters the design foundation configuration may consist of jacket structures supported by floating piles or by suction caissons. Taking the soil-structure interaction effects...... into consideration requires the prior estimation of the dynamic impedances of the foundation. Even though numerous studies exist for piles, only limited number of publications can be found for suction caissons subjected to dynamic loads. Therefore, the purpose of this study is to examine the dynamic response...... of this type of foundation using the finite element method (FEM) to account for the interaction with the soil. 3D numerical models for both the soil and the suction caisson are formulated in a frequency domain. The response of the soil surrounding the foundation is considered linear viscoelastic...

  2. Effect of a syringe aspiration technique versus a mechanical suction technique and use of N-butylscopolammonium bromide on the quantity and quality of bronchoalveolar lavage fluid samples obtained from horses with the summer pasture endophenotype of equine asthma.

    Science.gov (United States)

    Bowser, Jacquelyn E; Costa, Lais R R; Rodil, Alba U; Lopp, Christine T; Johnson, Melanie E; Wills, Robert W; Swiderski, Cyprianna E

    2018-03-01

    OBJECTIVE To evaluate the effect of 2 bronchoalveolar lavage (BAL) sampling techniques and the use of N-butylscopolammonium bromide (NBB) on the quantity and quality of BAL fluid (BALF) samples obtained from horses with the summer pasture endophenotype of equine asthma. ANIMALS 8 horses with the summer pasture endophenotype of equine asthma. PROCEDURES BAL was performed bilaterally (right and left lung sites) with a flexible videoendoscope passed through the left or right nasal passage. During lavage of the first lung site, a BALF sample was collected by means of either gentle syringe aspiration or mechanical suction with a pressure-regulated wall-mounted suction pump. The endoscope was then maneuvered into the contralateral lung site, and lavage was performed with the alternate fluid retrieval technique. For each horse, BAL was performed bilaterally once with and once without premedication with NBB (21-day interval). The BALF samples retrieved were evaluated for volume, total cell count, differential cell count, RBC count, and total protein concentration. RESULTS Use of syringe aspiration significantly increased total BALF volume (mean volume increase, 40 mL [approx 7.5% yield]) and decreased total RBC count (mean decrease, 142 cells/μL), compared with use of mechanical suction. The BALF nucleated cell count and differential cell count did not differ between BAL procedures. Use of NBB had no effect on BALF retrieval. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that retrieval of BALF by syringe aspiration may increase yield and reduce barotrauma in horses at increased risk of bronchoconstriction and bronchiolar collapse. Further studies to determine the usefulness of NBB and other bronchodilators during BAL procedures in horses are warranted.

  3. Report on technical measurements concerning measurement of the suction of tanks at Fangel biomass conversion plant

    International Nuclear Information System (INIS)

    1992-05-01

    The inconveniences caused by the odours emerging from the biomass conversion plant in Fangel, Denmark, and the actions taken in an attempt to reduce them, are described. The plant has on several occasions been threatened with being closed down because of the smell. Airtight coverings have been fixed on all the open tanks, and the suction element has been tested to see if it is airtight. Ozone has been added in order to help get rid of the smell. Measurements have shown that it is possible to attain a small vacuum in the storage tank under normal operation, if there is a surfeit of pumping there will be too high pressure. In relation to pumping-in the pressure can be too high in the first and medium tank. Flow, pressure, hydrogen sulphide and methane concentration changes significantly in relation to the various pumping frequences. The level of hydrogen sulphide removal in the biofilter was 70-85%. The flow of hydrogen sulphide becomes less after the addition of ozone. Measurements implied that the tanks were airtight. Larger vacuums can be achieved by changing the shape of the pipe system and increasing the flow. (AB)

  4. Seepage Study for Suction Installation of Bucket Foundation in Different Soil Combinations

    DEFF Research Database (Denmark)

    Koteras, Aleksandra Katarzyna; Ibsen, Lars Bo; Clausen, Johan Christian

    2016-01-01

    Research has proven the bucket foundation to be a feasible and an attractive solution for offshore wind turbines. Its potential derives partly from the cost-effectiveness due to the suction-assisted installation. The suction applied under the bucket lid produces a downward driving force and addit......Research has proven the bucket foundation to be a feasible and an attractive solution for offshore wind turbines. Its potential derives partly from the cost-effectiveness due to the suction-assisted installation. The suction applied under the bucket lid produces a downward driving force...... around the bucket skirt. The exceedance of critical suction might lead to installation failure due to formation of piping channels, which break the hydraulic seal between the skirt and soil. The excess pore pressure arising due to applied suction changes the effective stress, hence the penetration...

  5. Comprehensive experimental and numerical analysis of instability phenomena in pump turbines

    International Nuclear Information System (INIS)

    Gentner, Ch; Sallaberger, M; Widmer, Ch; Bobach, B-J; Jaberg, H; Schiffer, J; Senn, F; Guggenberger, M

    2014-01-01

    The changes in the electricity market have led to changed requirements for the operation of pump turbines. Utilities need to change fast and frequently between pumping and generating modes and increasingly want to operate at off-design conditions for extended periods. Operation of the units in instable areas of the machine characteristic is not acceptable and may lead to self-excited vibration of the hydraulic system. In turbine operation of pump turbines unstable behaviour can occur at low load off-design operation close to runaway conditions (S-shape of the turbine characteristic). This type of instability may impede the synchronization of the machine in turbine mode and thus increase start-up and switch over times. A pronounced S-shaped instability can also lead to significant drop of discharge in the event of load rejection. Low pressure on the suction side and in the tail-race tunnel could cause dangerous separation of the water column. Understanding the flow features that lead to the instable behaviour of pump turbines is a prerequisite to the design of machines that can fulfil the growing requirements relating to operational flexibility. Flow simulation in these instability zones is demanding due to the complex and highly unsteady flow patterns. Only unsteady simulation methods are able to reproduce the governing physical effects in these operating regions. ANDRITZ HYDRO has been investigating the stability behaviour of pump turbines in turbine operation in cooperation with several universities using simulation and measurements. In order to validate the results of flow simulation of unstable operating points, the Graz University of Technology (Austria) performed detailed experimental investigations. Within the scope of a long term research project, the operating characteristics of several pump turbine runners have been measured and flow patterns in the pump turbine at speed no load and runaway have been examined by 2D Laser particle image velocimetry (PIV

  6. Model based analysis of the time scales associated to pump start-ups

    Energy Technology Data Exchange (ETDEWEB)

    Dazin, Antoine, E-mail: antoine.dazin@lille.ensam.fr [Arts et métiers ParisTech/LML Laboratory UMR CNRS 8107, 8 bld Louis XIV, 59046 Lille cedex (France); Caignaert, Guy [Arts et métiers ParisTech/LML Laboratory UMR CNRS 8107, 8 bld Louis XIV, 59046 Lille cedex (France); Dauphin-Tanguy, Geneviève, E-mail: genevieve.dauphin-tanguy@ec-lille.fr [Univ Lille Nord de France, Ecole Centrale de Lille/CRISTAL UMR CNRS 9189, BP 48, 59651, Villeneuve d’Ascq cedex F 59000 (France)

    2015-11-15

    Highlights: • A dynamic model of a hydraulic system has been built. • Three periods in a pump start-up have been identified. • The time scales of each period have been estimated. • The parameters affecting the rapidity of a pump start-up have been explored. - Abstract: The paper refers to a non dimensional analysis of the behaviour of a hydraulic system during pump fast start-ups. The system is composed of a radial flow pump and its suction and delivery pipes. It is modelled using the bond graph methodology. The prediction of the model is validated by comparison to experimental results. An analysis of the time evolution of the terms acting on the total pump pressure is proposed. It allows for a decomposition of the start-up into three consecutive periods. The time scales associated with these periods are estimated. The effects of parameters (angular acceleration, final rotation speed, pipe length and resistance) affecting the start-up rapidity are then explored.

  7. Application of two turbulence models for computation of cavitating flows in a centrifugal pump

    International Nuclear Information System (INIS)

    He, M; Guo, Q; Zhou, L J; Wang, X; Wang, Z W

    2013-01-01

    To seek a better numerical method to simulate the cavitating flow field in a centrifugal pump, the applications between RNG k- ε and LES turbulence model were compared by using the Zwart-Gerber-Belamri cavitation model. It was found that both the models give almost the same results with respect to pump performance and cavitation evolutions including growth, local contraction, stability and separation in the impeller passage. But the LES model can not only capture the pump suction recirculation and the low frequency fluctuation caused by it, but also combine the changes of the shaft frequency amplitude acting on the impeller with the cavitation unstable characteristics. Thus the LES model has more advantages than RNG k- ε model in calculating the unsteady cavitating flow in a centrifugal pump

  8. Installation process of suction anchors in Gulf of Guinea clay : Centrifuge modelling

    OpenAIRE

    THOREL, Luc; GARNIER, Jacques; RAULT, Gérard; DENDANI, Hédi; COLLIAT, JL

    2010-01-01

    The preparation process of a deepwater Gulf of Guinea clay for modelling of 24 m long suction anchors at a scale of 1/100 in the LCPC centrifuge, the clay characteristics and the installation phase (self-weight and suction) are presented. Two types of caissons have been tested in each tub : one with stiffeners and the other without stiffener. The embedment ratio is close to the suction caisson's slenderness of 3. An analysis of the forces of suction and soil friction shows, as expected, hi...

  9. Detection of cavitation inception by acoustic technique in centrifugal pumps for nuclear application

    International Nuclear Information System (INIS)

    Prakash, V.; Prabhakar, R.; Rao, A.S.L.K.; Kale, R.D.

    1994-01-01

    The primary centrifugal pumps in a pool type reactor like the proposed Prototype Fast Breeder Reactor (PFBR) are required to operate at low values of available net positive suction head due to the limited submergence available in the pool. Pump hydraulics are designed to ensure that there is no cavitation or only minimum cavitation in the pump impeller in order to minimise long term erosion damage. Rigorous cavitation tests are usually carried out during development and final testing phase and a promising cavitation detection technique lies in acoustic noise measurements on the pump. As part of PFBR pump development programme, cavitation noise measurements were initially carried out on an experimental sodium pump in a water rig to establish detection procedures. Recently cavitation noise measurements were carried out on a 1/3 scale model impeller of PFBR pump along with visual observation of impeller passages to establish a correlation between visual and acoustic technique. Accelerometer responding to structure borne noise seems to give the best result. (author). 4 refs., 6 figs

  10. Dynamic stiffness of suction caissons

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten; Andersen, Lars

    This report concerns the dynamic soil-structure interaction of steel suction caissons applied as foundations for offshore wind turbines. An emphasis is put on torsional vibrations and coupled sliding/rocking motion, and the influence of the foundation geometry and the properties of the surrounding...... soil is examined. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency-dependent coefficients corresponding to the different degrees of freedom. The dynamic stiffness coefficients...... for the skirted foundation are evaluated by means of a three-dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been...

  11. Cavitation performance improvement of high specific speed mixed-flow pump

    International Nuclear Information System (INIS)

    Chen, T; Sun, Y B; Wu, D Z; Wang, L Q

    2012-01-01

    Cavitation performance improvement of large hydraulic machinery such as pump and turbine has been a hot topic for decades. During the design process of the pumps, in order to minimize size, weight and cost centrifugal and mixed-flow pump impellers are required to operate at the highest possible rotational speed. The rotational speed is limited by the phenomenon of cavitation. The hydraulic model of high-speed mixed-flow pump with large flow rate and high pumping head, which was designed based on the traditional method, always involves poor cavitation performance. In this paper, on the basis of the same hydraulic design parameters, two hydraulic models of high-speed mixed-flow pump were designed by using different methods, in order to investigate the cavitation and hydraulic performance of the two models, the method of computational fluid dynamics (CFD) was adopted for internal flow simulation of the high specific speed mixed-flow pump. Based on the results of numerical simulation, the influences of impeller parameters and three-dimensional configuration on pressure distribution of the blades' suction surfaces were analyzed. The numerical simulation results shows a better pressure distribution and lower pressure drop around the leading edge of the improved model. The research results could provide references to the design and optimization of the anti-cavitation blade.

  12. Integrated main coolant pumps for pressurized-water reactors

    International Nuclear Information System (INIS)

    Wieser, R.

    1975-01-01

    The efficiency of an integrated main coolant pump for PWR's is increased. For this purpose, the pump is installed eccentric relative to the vertical axis of the U-type steam generator in the three-section HP chamber in such a way that its impeller wheel and the shell of the latter penetrate into the outlet chamber. The axis of the pump lies in the vertical plane of symmetry of the outlet chamber of the steam generator. The suction tube is arranged in the outlet chamber. To allow it to be installed, it is manufactured out of several parts. The diffusor tube, which is also made of several components, is attached to the horizontal separation plate between the outlet chamber and the pressure chamber so as to penetrate into it. To improve the outflow conditions at the diffusor tube, a plowshare-shaped baffle shield is installed between the diffusor tube and the HP chamber. Moreover, in order to improve the outflow conditions from the pump and from the pressure chamber, the outflow opening of the pressure chamber is put into the cylindrical shell of the HP chamber. In this way, the tensioning anchor is located between the pump and the outlet opening. (DG/RF) [de

  13. Multiphase pumping: indoor performance test and oilfield application

    Science.gov (United States)

    Kong, Xiangling; Zhu, Hongwu; Zhang, Shousen; Li, Jifeng

    2010-03-01

    Multiphase pumping is essentially a means of adding energy to the unprocessed effluent which enables the liquid and gas mixture to be transported over a long distances without prior separation. A reduction, consolidation, or elimination of the production infrastructure, such as separation equipments and offshore platforms can be developed more economically. Also it successfully lowed the backpressure of wells, revived dead wells and improved the production and efficiency of oilfield. This paper reviews the issues related to indoor performance test and an oilfield application of the helico-axial multiphase pump designed by China University of Petroleum (Beijing). Pump specification and its hydraulic design are given. Results of performance testing under different condition, such as operational speed and gas volume fraction (GVF) etc are presented. Experimental studies on combination of theoretical analysis showed the multiphase pump satisfies the similitude rule, which can be used in the development of new MPP design and performance prediction. Test results showed that rising the rotation speed and suction pressure could better its performance, pressure boost improved, high efficiency zone expanding and the flow rate related to the optimum working condition increased. The pump worked unstable as GVF increased to a certain extent and slip occurred between two phases in the pump, creating surging and gas lock at a high GVF. A case of application in Nanyang oilfield is also studied.

  14. Flow measurements in a model centrifugal pump by 3-D PIV

    International Nuclear Information System (INIS)

    Yang, H; Xu, H R; Liu, C

    2012-01-01

    PIV (Particle Image Velocimetry), as an non-intrusive flow measurements technology, is widely used to investigate the flow fields in many areas. 3-D (three Dimensional) PIV has seldom been used to measure flow field in rotational impeller of centrifugal pump due to the difficulty of calibration in samll space. In this article, a specially manufactured water tank was used to perform the calibration for 3-D PIV measurement. The instantaneous absolute velocity in one impeller passage was obtained by merging of three sub zones and the relative velocity was acquired by velocity decomposition. The result shows that, when the pump runs at the condition of design flow rate, the radial component velocity W r appears a concave distribution except the condition of R=45 mm. With the increase of radius, the circumference location of the minimum radial component velocity W r moves from the pressure side to the suction side. At the same time, the tangential component velocity W θ on the suction side decreases gradually with the increase of radius, while the component on the pressure side increases gradually. The secondary flow in different radius section has also been shown. At last, the error of PIV measurements was analyzed, which shows that the test results are accurate and the measured data is reliable.

  15. Experiment of a centrifugal pump during changing speed operation

    International Nuclear Information System (INIS)

    Yuan, H J; Wu, Y L; Liu, S H; Shao, J

    2012-01-01

    In this paper, a method of changing rotational speed of impeller periodically as the pulsatile working condition is developed to realize pulse outputs both of flow discharge and of head for a centrifugal pump through experiment. The performance of the centrifugal pump under pulsatile working operation condition is measured which indicates this model pump could produce desired pulse flow under such condition. Flow patterns at four testing points under pulsatile conditions are obtained by means of the particle image velocimetry (PIV) technology both with laser induced fluorescence (LIF) particles and refractive index matched (RIM) fluid. Results of PIV measurement show the distributions of velocity, streamlines, and the principal Reynolds normal stress (PRNS). Under the design flow rate condition, the relative velocity in the blade channel distributes smoothly and decreases from inlet to exit. And at the impeller exit, the relative velocity is lower close to suction side than that near pressure side of blade in most of blade channels.

  16. Method of controlling the operation of a feedwater system

    International Nuclear Information System (INIS)

    Takemaru, Koichi; Omori, Takashi.

    1975-01-01

    Object: At the time of pump trip at upstream, to maintain a good operating characteristic without stopping a pump at the downstream. Structure: In the event that one of pumps at the upstream (for example, a condenser pump) is tripped, interlock is activated to forcibly open a circulating valve for a condensation booster pump to partly return the flow rate of discharge to a pump suction part, thus preventing a decrease in suction pressure. In this case, in order to control suction pressure to a suitable level of pressure more than a net suction water head as required, a pressure adjusting meter for the condensation booster pump is provided on a pipe line on the side of suction so that the flow rate of circulation may be changed by the pressure adjusting valve to maintain the suction pressure in constant. (Kawakami, Y.)

  17. An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump

    Science.gov (United States)

    Lindley, B. K.; Martinson, A. R.

    1971-01-01

    The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

  18. Investigation of the Hydrodynamics of Sweep Blade in Hi-Speed Axial Fuel Pump Impeller

    Directory of Open Access Journals (Sweden)

    Ran Tao

    2013-01-01

    Full Text Available Fuel pump is a crucial component in aircraft engine ignition system. For the hi-speed axial fuel pumps, rotating stall triggers vortex and affects the operation stability and security. Sweep blade is widely used to solve the stability problems in aerodynamics field. Investigation on the hydrodynamics was conducted in this study. Based on the typical straight blade pump, positive and negative sweep blade pumps were modeled. With the large eddy simulation method, CFD simulations were conducted to calculate and analyze the flow characteristics in the pump models. To verify the simulation, experiments were also launched on the hydraulic test rig. Results show that the vortex occurs at the suction surface of blade and gathers near the blade tip region. Positive sweep blade is effective to reduce the hydraulic losses by driving the stalled fluid into the mid-part of blade. By applying the positive sweep blade on the axial fuel pump, the instability operating region will be diminished. Adopting sweep blade provides an effective means for stability and security of axial fuel pumps.

  19. Effects of shallow and deep endotracheal tube suctioning on cardiovascular indices in patients in intensive care units.

    Science.gov (United States)

    Irajpour, Alireza; Abbasinia, Mohammad; Hoseini, Abbas; Kashefi, Parviz

    2014-07-01

    Clearing the endotracheal tube through suctioning should be done to promote oxygenation. Depth of suctioning is one of the variables in this regard. In shallow suctioning method, the catheter passes to the tip of the endotracheal tube, and in deep suctioning method, it passes beyond the tip into the trachea or brunches. This study aimed to evaluate the effect of shallow and deep suctioning methods on cardiovascular indices in patients hospitalized in the intensive care units (ICUs). In this clinical trial, 74 patients were selected among those who had undergone mechanical ventilation in the ICU of Al-Zahra Hospital, Isfahan, Iran using convenience sampling method. The subjects were randomly allocated to shallow and deep suctioning groups. Heart rate (HR) and blood pressure (BP) were measured immediately before and 1, 2, and 3 min after each suctioning. Number of times of suctioning was also noted in both the groups. Data were analyzed using repeated measures analysis of variance (ANOVA), Chi-square and independent t-tests. HR and BP were significantly increased after suctioning in both the groups (P 0.05). The suctioning count was significantly higher in the shallow suctioning group than in the deep suctioning group. Shallow and deep suctioning were similar in their effects on HR and BP, but shallow suctioning caused further manipulation of patient's trachea than deep suctioning method. Therefore, in order to prevent complications, nurses are recommended to perform the endotracheal tube suctioning by the deep method.

  20. Dynamic stiffness of suction caissons - vertical vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.; Andersen, Lars

    2006-12-15

    The dynamic response of offshore wind turbines are affected by the properties of the foundation and the subsoil. The purpose of this report is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigation is limited to a determination of the vertical dynamic stiffness of suction caissons. The soil surrounding the foundation is homogenous with linear viscoelastic properties. The dynamic stiffness of the suction caisson is expressed by dimensionless frequency-dependent dynamic stiffness coefficients corresponding to the vertical degree of freedom. The dynamic stiffness coefficients for the foundations are evaluated by means of a dynamic three-dimensional coupled Boundary Element/Finite Element model. Comparisons are made with known analytical and numerical solutions in order to evaluate the static and dynamic behaviour of the Boundary Element/Finite Element model. The vertical frequency dependent stiffness has been determined for different combinations of the skirt length, Poisson's ratio and the ratio between soil stiffness and skirt stiffness. Finally the dynamic behaviour at high frequencies is investigated. (au)

  1. PUMP: analog-hybrid reactor coolant hydraulic transient model

    International Nuclear Information System (INIS)

    Grandia, M.R.

    1976-03-01

    The PUMP hybrid computer code simulates flow and pressure distribution; it is used to determine real time response to starting and tripping all combinations of PWR reactor coolant pumps in a closed, pressurized, four-pump, two-loop primary system. The simulation includes the description of flow, pressure, speed, and torque relationships derived through pump affinity laws and from vendor-supplied pump zone maps to describe pump dynamic characteristics. The program affords great flexibility in the type of transients that can be simulated

  2. Fastest predators in the plant kingdom: functional morphology and biomechanics of suction traps found in the largest genus of carnivorous plants

    Science.gov (United States)

    Poppinga, Simon; Weisskopf, Carmen; Westermeier, Anna Sophia; Masselter, Tom; Speck, Thomas

    2016-01-01

    Understanding the physics of plant movements, which describe the interplay between plant architecture, movement speed and actuation principles, is essential for the comprehension of important processes like plant morphogenesis. Recent investigations especially on rapid plant movements at the interface of biology, physics and engineering sciences highlight how such fast motions can be achieved without the presence of muscles, nerves and technical hinge analogies. The suction traps (bladders) of carnivorous bladderworts (Utricularia spp., Lentibulariaceae, Lamiales) are considered as some of the most elaborate moving structures in the plant kingdom. A complex interplay of morphological and physiological adaptations allows the traps to pump water out of their body and to store elastic energy in the deformed bladder walls. Mechanical stimulation by prey entails opening of the otherwise watertight trapdoor, followed by trap wall relaxation, sucking in of water and prey, and consecutive trapdoor closure. Suction can also occur spontaneously in non-stimulated traps. We review the current state of knowledge about the suction trap mechanism with a focus on architectonically homogeneous traps of aquatic bladderwort species from section Utricularia (the so-called ‘Utricularia vulgaris trap type’). The functional morphology and biomechanics of the traps are described in detail. We discuss open questions and propose promising aspects for future studies on these sophisticated ultra-fast trapping devices. PMID:26602984

  3. Spinal cord electrophysiology II: extracellular suction electrode fabrication.

    Science.gov (United States)

    Garudadri, Suresh; Gallarda, Benjamin; Pfaff, Samuel; Alaynick, William

    2011-02-20

    Development of neural circuitries and locomotion can be studied using neonatal rodent spinal cord central pattern generator (CPG) behavior. We demonstrate a method to fabricate suction electrodes that are used to examine CPG activity, or fictive locomotion, in dissected rodent spinal cords. The rodent spinal cords are placed in artificial cerebrospinal fluid and the ventral roots are drawn into the suction electrode. The electrode is constructed by modifying a commercially available suction electrode. A heavier silver wire is used instead of the standard wire given by the commercially available electrode. The glass tip on the commercial electrode is replaced with a plastic tip for increased durability. We prepare hand drawn electrodes and electrodes made from specific sizes of tubing, allowing consistency and reproducibility. Data is collected using an amplifier and neurogram acquisition software. Recordings are performed on an air table within a Faraday cage to prevent mechanical and electrical interference, respectively.

  4. Water born pollutants sampling using porous suction samples

    International Nuclear Information System (INIS)

    Baig, M.A.

    1997-01-01

    The common standard method of sampling water born pollutants in the vadoze zone is core sampling and it is followed by extraction of pore fluid. This method does not allow sampling at the same location next time and again later on. There is an alternative approach for sampling fluids (water born pollutants) from both saturated and unsaturated regions of vadose zone using porous suction samplers. There are three types of porous suction samplers, vacuum-operated, pressure-vacuum lysimeters, high pressure vacuum samples. The suction samples are operated in the range of 0-70 centi bars and usually consist of ceramic and polytetrafluorethylene (PTFE). The operation range of PTFE is higher than ceramic cups. These samplers are well suited for in situ and repeated sampling form the same location. This paper discusses the physical properties and operating condition of such samplers to the utilized under our environmental sampling. (author)

  5. Effect of suction on the mechanical characteristics of uniformly compacted rammed earth

    Science.gov (United States)

    El Hajjar, A.; Chauhan, P.; Prime, N.; Plé, O.

    2018-04-01

    Rammed earth, in the current environmental situation, is an alternative construction technique which can help in reducing energy and raw material consumption owing to its “sustainable” characteristics. To fully understand its behavior and properties, recent scientific investigations consider it as a compacted unsaturated material with suction as its one of the main sources of strength. Eathern constructions face, over their lifetime, variations in the suction state which have a significant impact on their mechanical characteristics. In the present contribution, unconfined compression tests are performed, with and without unload-reload cycles, on homogeneously compacted samples subjected to various suction conditions. This study shows that both the unconfined compressive strength and Young modulus reduce with the reduction of suction states. Suction also seems to influence the amount of plastic strains and damage phenomenon. Indeed, the soils analyzed are slightly active and shows both plasticity behavior and damage phenomenon.

  6. Work plan, AP-102 mixer pump removal and pump replacement

    International Nuclear Information System (INIS)

    Jimenez, R.F.

    1994-01-01

    The objective of this work plan is to plan the steps and estimate the costs required to remove the failed AP-102 mixer pump, and to plan and estimate the cost of the necessary design and specification work required to order a new, but modified, mixer pump including the pump and pump pit energy absorbing design. The main hardware required for the removal of the mixer is as follows: a flexible receiver and blast shield; a metal container for the pulled mixer pump; and a trailer and strongback to haul and manipulate the container. Additionally: a gamma scanning device will be needed to detect the radioactivity emanating from the mixer as it is pulled from the tank; a water spray system will be required to remove tank waste from the surface of the mixer as it is pulled from the AP-102 tank; and a lifting yoke to lift the mixer from the pump pit (the SY-101 Mixer Lifting Yoke will be used). A ''green house'' will have to be erected over the AP-102 pump pit and an experienced Hoisting and Rigging crew must be assembled and trained in mixer pump removal methods before the actual removal is undertaken

  7. Avaliação de tanques de escorva utilizados em substituição à válvula-de-pé em instalações de bombeamento Evaluation of priming tanks using them instead of foot valve in pumping installations

    Directory of Open Access Journals (Sweden)

    Marcos O. Betini

    2008-09-01

    Full Text Available A maioria das instalações de abastecimento de água utiliza bombas hidráulicas do tipo turbobombas, requerendo que o interior de sua carcaça e da tubulação de sucção esteja preenchido com água (escorvados para que a sucção da água possa ser efetivada. O escorvamento das bombas pode ser efetuado instalando-as abaixo do reservatório de captação (bomba afogada. Quando a bomba está acima do reservatório e o escorvamento é manual, é necessário usar válvulas-de-pé, que são suscetíveis ao mau funcionamento, limitando a confiabilidade do sistema, principalmente em caso de automação. Como alternativa à válvula-de-pé, neste trabalho, foram estudados dois tanques escorva, testados no Laboratório de Hidráulica e Irrigação da FCAV/UNESP - Jaboticabal, avaliando-se situações de altura manométrica de sucção de bomba centrífuga e relações entre volume útil do tanque e volume do tubo de sucção, tendo-se concluído: a o volume do tanque de escorva é função do volume do tubo de sucção da instalação de bombeamento e da altura manométrica de sucção; b o volume do tanque de escorva pode ser calculado seguindo-se a Lei de Boyle, com percentagem de acréscimo que, neste estudo, foi de 10% para um modelo de tanque e de 30% para o segundo modelo.The majority of water supply installations use hydraulic pump-turbines, requiring their inner casing and suction pipe be water filled (primed, to allow water suction. Pumps priming can be carried out installing them under the suction reservoir (drowned pump. When pump is above the reservoir and priming is manual, it will be necessary using foot valves, which are subjected to bad working, with a reduction of system reliability, mainly with automation. In this work, as an alternative to foot valves, two priming tanks were inquired, tested in the FCAV/UNESP-Jaboticabal, Brazil, Laboratory of Hydraulics and Irrigation, with the evaluation of suction head situations of centrifugal

  8. Simulations of Micropumps Based on Tilted Flexible Fibers

    Science.gov (United States)

    Hancock, Matthew; Elabbasi, Nagi; Demirel, Melik

    2015-11-01

    Pumping liquids at low Reynolds numbers is challenging because of the principle of reversibility. We report here a class of microfluidic pump designs based on tilted flexible structures that combines the concepts of cilia (flexible elastic elements) and rectifiers (e.g., Tesla valves, check valves). We demonstrate proof-of-concept with 2D and 3D fluid-structure interaction (FSI) simulations in COMSOL Multiphysics®of micropumps consisting of a source for oscillatory fluidic motion, e.g. a piston, and a channel lined with tilted flexible rods or sheets to provide rectification. When flow is against the rod tilt direction, the rods bend backward, narrowing the channel and increasing flow resistance; when flow is in the direction of rod tilt, the rods bend forward, widening the channel and decreasing flow resistance. The 2D and 3D simulations involve moving meshes whose quality is maintained by prescribing the mesh displacement on guide surfaces positioned on either side of each flexible structure. The prescribed displacement depends on structure bending and maintains mesh quality even for large deformations. Simulations demonstrate effective pumping even at Reynolds numbers as low as 0.001. Because rod rigidity may be specified independently of Reynolds number, in principle, rod rigidity may be reduced to enable pumping at arbitrarily low Reynolds numbers.

  9. Deep versus shallow suction of endotracheal tubes in ventilated neonates and young infants.

    Science.gov (United States)

    Gillies, Donna; Spence, Kaye

    2011-07-06

    Mechanical ventilation is commonly used in Neonatal Intensive Care Units to assist breathing in a variety of conditions. Mechanical ventilation is achieved through the placement of an endotracheal tube (ETT) which is left in-situ. The ETT is suctioned to prevent a build-up of secretions and blockage of the airway. Methods of suctioning the endotracheal tube vary according to institutional practice and the individual clinician performing the task. The depth of suctioning is one of these variables. The catheter may be passed to the tip of the ETT or beyond the tip into the trachea or bronchi to facilitate removal of secretions. However, trauma to the lower airways may result from the suction catheter being passed into the airway beyond the tip of the endotracheal tube. To compare the effectiveness and complications of deep (catheter passed beyond the tip of the ETT) versus shallow (catheter passed to length of ETT only) suctioning of the endotracheal tube in ventilated infants. In this first update the searches were expanded to the Cochrane Central Register of Controlled Trials (The Cochrane Library, March 30), MEDLINE (from January 1966 to May 30 2011), CINAHL (from 1982 to May 30 2011) and EMBASE (1980 to May 2011) using text words and subject headings relevant to endotracheal suctioning. There were no language restrictions. Controlled trials using random or quasi-random allocation of neonates receiving ventilatory support via an endotracheal tube to either deep or shallow endotracheal suctioning. The updated search resulted in 149 potentially relevant references. Two of the studies from this search were identified as potentially relevant. We included one of the potentially relevant studies and the other was excluded because it did not fit the inclusion criteria. One small crossover trial (n = 27) of shallow versus deep suctioning met the criteria for inclusion in this review. The reported outcomes were oxygen saturation and heart rate, during and after suctioning

  10. Numerical Buckling Analysis of Large Suction Caissons for Wind Turbines on Deep Water

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2013-01-01

    Using large suction caissons for offshore wind turbines is an upcoming cost-effective technology also referred to as bucket foundations. During operation, the monopod bucket foundation is loaded by a large overturning moment from the wind turbine and the wave loads. However, during installation...... the suction caisson is loaded by external pressure (internal suction) due to evacuation of water inside the bucket and vertical forces due to gravity. The risk of structural buckling during installation of large-diameter suction caissons is addressed using numerical methods. Initial imperfect geometries...

  11. Earthquake resistance of residual heat removed (RHR) pump for pressurized water reactors (PWR)

    International Nuclear Information System (INIS)

    Uga, Takeo; Shiraki, K.; Honma, T.; Matsubayashi, H.; Inazuka, H.

    1980-01-01

    The present paper deals with the earthquake resistance of the residual heat removed (RHR) pump of single stage double volute type, which is one of the structurally simplest pumps used for pressurized water reactors (PWR). The results of the study can be summarized as follows: (1) Any trouble which can give effect on the functions of the pump at earthquake does not become a problem so long as each part of the pump is of aseismatically rigid structure. (2) Aseismatic tolerance test in the pump's operating condition has shown that the earthquake resistance of the pump at its location has a tolerance about five times the dynamic design acceleration. (3) The pump is provided with an impeller-casing wear ring at the pressure boundary between the suction side pressure and discharge side pressure. This wear ring acts as an underwater bearing when the pump is in operation, and improves the vibration characteristics, particularly damping ratio, of the pump shaft to a great extent to make the pump more aseismatic. (4) In the evaluation of the underwater bearing characteristics of the wear ring, the evaluation accuracy of the vibration characteristics of the pump shaft can be improved by taking into consideration the pressure loss in the wear ring part from the head of the single stage of the pump due to the rotation of the impeller. (author)

  12. Vortex lift augmentation by suction on a 60 deg swept Gothic wing

    Science.gov (United States)

    Taylor, A. H.; Jackson, L. R.; Huffman, J. K.

    1982-01-01

    An experimental investigation was conducted in the Langley high-speed 7- by 10-foot wind tunnel to determine the aerodynamic performance of suction applied near the wing tips above the trailing edge of a 60 deg swept Gothic wing. Moveable suction inlets were symmetrically mounted in the proximity of the trailing edge, and the amount of suction was varied to maximize wing lift. Tests were conducted at Mach 0.15, 0.30, and 0.45, and the angle of attack was varied from -4 to 50 deg. The suction augmentation increases the lift coefficient over the entire range of angle of attack. The lift improvement exceeds the unaugmented wing lift by over 20%. Moreover, the augmented lift exceeds the lift predicted by vortex lattice theory to 30 deg angle of attack. Suction augmentation is postulated to strengthen the vortex system by increasing its velocity and making it more concentrated. This causes the vortex breakdown to be delayed to a higher angle of attack

  13. Evaluation of Karl Storz CMAC TipTM Device Versus Traditional Airway Suction in a Cadaver Model

    Directory of Open Access Journals (Sweden)

    Demis N. Lipe

    2014-07-01

    Full Text Available Introduction: We compared the efficacy of Karl Storz CMAC TipTM with inline suction to CMAC with traditional suction device in cadaveric models simulating difficult airways, using media mimicking pulmonary edema and vomit. Methods: This was a prospective, cohort study in which we invited emergency medicine faculty and residents to participate. Each participant intubated 2 cadavers (one with simulated pulmonary edema and one with simulated vomit, using CMAC with inline suction and CMAC with traditional suction. Thirty emergency medicine providers performed 4 total intubations each in a crossover trial comparing the CMAC with inline suction and CMAC with traditional suction. Two intubations were performed with simulated vomit and two with simulated pulmonary edema. The primary outcome was time to successful intubation; and the secondary outcome was proportion of successful intubation. Results: The median time to successful intubation using the CMAC with inline suction versus traditional suction in the pulmonary edema group was 29s and 30s respectively (p=0.54. In the vomit simulation, the median time to successful intubation was 40s using the CMAC with inline suction and 41s using the CMAC with traditional suction (p=0.70. There were no significant differences in time to successful intubation between the 2 devices. Similarly, the proportions of successful intubation were also not statistically significant between the 2 devices. The proportions of successful intubations using the inline suction were 96.7% and 73.3%, for the pulmonary edema and vomit groups, respectively. Additionally using the handheld suction device, the proportions for the pulmonary edema and vomit group were 100% and 66.7%, respectively. Conclusion: CMAC with inline suction was no different than CMAC with traditional suction and was associated with no statistically significant differences in median time to intubation or proportion of successful intubations. [West J Emerg Med

  14. Absence of suction feeding ichthyosaurs and its implications for triassic mesopelagic paleoecology.

    Science.gov (United States)

    Motani, Ryosuke; Ji, Cheng; Tomita, Taketeru; Kelley, Neil; Maxwell, Erin; Jiang, Da-yong; Sander, Paul Martin

    2013-01-01

    Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were 'ram-feeders', without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern

  15. Pumped Storage and Potential Hydropower from Conduits

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2015-02-25

    Th is Congressional Report, Pumped Storage Hydropower and Potential Hydropower from Conduits, addresses the technical flexibility that existing pumped storage facilities can provide to support intermittent renewable energy generation. This study considered potential upgrades or retrofit of these facilities, the technical potential of existing and new pumped storage facilities to provide grid reliability benefits, and the range of conduit hydropower opportunities available in the United States.

  16. Energy system investment model incorporating heat pumps with thermal storage in buildings and buffer tanks

    DEFF Research Database (Denmark)

    Hedegaard, Karsten; Balyk, Olexandr

    2013-01-01

    Individual compression heat pumps constitute a potentially valuable resource in supporting wind power integration due to their economic competitiveness and possibilities for flexible operation. When analysing the system benefits of flexible heat pump operation, effects on investments should...... be taken into account. In this study, we present a model that facilitates analysing individual heat pumps and complementing heat storages in integration with the energy system, while optimising both investments and operation. The model incorporates thermal building dynamics and covers various heat storage...... of operating heat pumps flexibly. This includes prioritising heat pump operation for hours with low marginal electricity production costs, and peak load shaving resulting in a reduced need for peak and reserve capacity investments....

  17. Morphology, Kinematics, and Dynamics: The Mechanics of Suction Feeding in Fishes.

    Science.gov (United States)

    Day, Steven W; Higham, Timothy E; Holzman, Roi; Van Wassenbergh, Sam

    2015-07-01

    Suction feeding is pervasive among aquatic vertebrates, and our understanding of the functional morphology and biomechanics of suction feeding has recently been advanced by combining experimental and modeling approaches. Key advances include the visualization of the patterns of flow in front of the mouth of a feeding fish, the measurement of pressure inside their mouth cavity, and the employment of analytical and computational models. Here, we review the key components of the morphology and kinematics of the suction-feeding system of anatomically generalized, adult ray-finned fishes, followed by an overview of the hydrodynamics involved. In the suction-feeding apparatus, a strong mechanistic link among morphology, kinematics, and the capture of prey is manifested through the hydrodynamic interactions between the suction flows and solid surfaces (the mouth cavity and the prey). It is therefore a powerful experimental system in which the ecology and evolution of the capture of prey can be studied based on first principals. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  18. The Influence of Swirl Brakes and a Tip Discharge Orifice on the Rotordynamic Forces Generated by Discharge-to-Suction Leakage Flows in Shrouded Centrifugal Pumps

    Science.gov (United States)

    Sivo, Joseph M.; Acosta, A. J.; Brennen, C. E.; Caughey, T. K.

    1993-01-01

    Recent experiments conducted in the Rotor Force Test Facility at the California Institute of Technology have examined the effects of a tip leakage restriction and swirl brakes on the rotordynamic forces due to leakage flows on an impeller undergoing a prescribed circular whirl. The experiments simulate the leakage flow conditions and geometry of the Alternate Turbopump Design (ATD) of the Space Shuttle High Pressure Oxygen Turbopump and are critical to evaluating the pump's rotordynamic instability problems. Previous experimental and analytical results have shown that discharge-to-suction leakage flows in the annulus of a shrouded centrifugal pump contribute substantially to the fluid induced rotordynamic forces. Also, previous experiments have shown that leakage inlet (pump discharge) swirl can increase the cross-coupled stiffness coefficient and hence increase the range of positive whirl for which the tangential force is destabilizing. In recent experimental work, the present authors demonstrated that when the swirl velocity within the leakage path is reduced by the introduction of ribs or swirl brakes, then a substantial decrease in both the destabilizing normal and tangential forces could be achieved. Motivation for the present research is that previous experiments have shown that restrictions such as wear rings or orifices at pump inlets affect the leakage forces. Recent pump designs such as the Space Shuttle Alternate Turbopump Design (ATD) utilize tip orifices at discharge for the purpose of establishing axial thrust balance. The ATD has experienced rotordynamic instability problems and one may surmise that these tip discharge orifices may also have an important effect on the normal and tangential forces in the plane of impeller rotation. The present study determines if such tip leakage restrictions contribute to undesirable rotordynamic forces. Additional motivation for the present study is that the widening of the leakage path annular clearance and the

  19. Investigations of internal turbulent flows in a low-head tubular pump and its performance predictions

    International Nuclear Information System (INIS)

    Tang, X L; Chen, X S; Wang, F J; Yang, W; Wu, Y L

    2012-01-01

    Based on the RANS equations, standard k−ε turbulence model and SIMPLE algorithm, the internal turbulent flows in a low-head tubular pump were simulated by using the FLUENT software. Based on the predicted flow fields, the external performance curves including the head-discharge, efficiency-discharge and power-discharge curves were further obtained. The calculated results indicate that the internal flow pattern is smooth at the best efficiency point (BEP). When it works under off-design operating cases, the flow pattern inside the diffuser and the discharge passage is disorder, and at the same time, the hydraulic losses mainly come from the secondary flows. At large flow rates, the minimum static pressure near the inlet of the blade pressure surfaces due to the negative attack angle. At small flow rates, the minimum value happens near the inlet of the suction surfaces. At the BEP, the lowest static pressure appears in the region behind the suction surfaces inlet. The newly-designed model is validated by the comparisons between its predicted external performance and the experimental data of the JGM-3 model. This research provides some important references for the optimization of a low-head tubular pump.

  20. Turbulent flow with suction in smooth and rough pipes

    International Nuclear Information System (INIS)

    Verdier, Andre.

    1977-11-01

    It concerns an experimental study of turbulent flow inside a pipe with rough and porous wall and suction applied through it. The first part recall the basic knowledge concerning the turbulent flow with roughness. In second part statistical equations of fluid wall stress are written in the case of a permeable rough wall, in order to underline the respective role played by viscosity and pressure terms. In the third part the dynamic equilibrium of the flow is experimentally undertaken in the smooth and rough range with and without wall suction. Some empirical formulae are proposed for the mean velocity profiles in the inertial range and for friction velocity with suction. In the case of the sand roughness used, it does not seem that critical Reynolds number of transition from smooth to rough range is varied [fr

  1. A compliant underactuated hand with suction flow for underwater mobile manipulation

    KAUST Repository

    Stuart, Hannah S.

    2014-05-01

    © 2014 IEEE. Fingertip suction is investigated using a compliant, underactuated, tendon-driven hand designed for underwater mobile manipulation. Tendon routing and joint stiffnesses are designed to provide ease of closure while maintaining finger rigidity, allowing the hand to pinch small objects, as well as secure large objects, without diminishing strength. While the hand is designed to grasp a range of objects, the addition of light suction flow to the fingertips is especially effective for small, low-friction (slippery) objects. Numerical simulations confirm that changing suction parameters can increase the object acquisition region, providing guidelines for future versions of the hand.

  2. A compliant underactuated hand with suction flow for underwater mobile manipulation

    KAUST Repository

    Stuart, Hannah S.; Wang, Shiquan; Gardineer, Bayard; Christensen, David L.; Aukes, Daniel M.; Cutkosky, Mark

    2014-01-01

    © 2014 IEEE. Fingertip suction is investigated using a compliant, underactuated, tendon-driven hand designed for underwater mobile manipulation. Tendon routing and joint stiffnesses are designed to provide ease of closure while maintaining finger rigidity, allowing the hand to pinch small objects, as well as secure large objects, without diminishing strength. While the hand is designed to grasp a range of objects, the addition of light suction flow to the fingertips is especially effective for small, low-friction (slippery) objects. Numerical simulations confirm that changing suction parameters can increase the object acquisition region, providing guidelines for future versions of the hand.

  3. Absence of suction feeding ichthyosaurs and its implications for triassic mesopelagic paleoecology.

    Directory of Open Access Journals (Sweden)

    Ryosuke Motani

    Full Text Available Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were 'ram-feeders', without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the

  4. A Technique for Controlling Matric Suction on Filter Papers . GroWth ...

    African Journals Online (AJOL)

    'Abstract. Moist filter papers are widely usedfor seed gennination tests but their water confent and matric suction are not usually controlled. A technique for controlling filter paper matric suction is described and usedfor germination studies involving fresh and aged sorghum seed (Sorghummcolor (L) Moench). Filter papers ...

  5. A comparison of commercial light-emitting diode baited suction traps for surveillance of Culicoides in northern Europe.

    Science.gov (United States)

    Hope, Andrew; Gubbins, Simon; Sanders, Christopher; Denison, Eric; Barber, James; Stubbins, Francesca; Baylis, Matthew; Carpenter, Simon

    2015-04-22

    The response of Culicoides biting midges (Diptera: Ceratopogonidae) to artificial light sources has led to the use of light-suction traps in surveillance programmes. Recent integration of light emitting diodes (LED) in traps improves flexibility in trapping through reduced power requirements and also allows the wavelength of light used for trapping to be customized. This study investigates the responses of Culicoides to LED light-suction traps emitting different wavelengths of light to make recommendations for use in surveillance. The abundance and diversity of Culicoides collected using commercially available traps fitted with Light Emitting Diode (LED) platforms emitting ultraviolet (UV) (390 nm wavelength), blue (430 nm), green (570 nm), yellow (590 nm), red (660 nm) or white light (425 nm - 750 nm with peaks at 450 nm and 580 nm) were compared. A Centre for Disease Control (CDC) UV light-suction trap was also included within the experimental design which was fitted with a 4 watt UV tube (320-420 nm). Generalised linear models with negative binomial error structure and log-link function were used to compare trap abundance according to LED colour, meteorological conditions and seasonality. The experiment was conducted over 49 nights with 42,766 Culicoides caught in 329 collections. Culicoides obsoletus Meigen and Culicoides scoticus Downes and Kettle responded indiscriminately to all wavelengths of LED used with the exception of red which was significantly less attractive. In contrast, Culicoides dewulfi Goetghebuer and Culicoides pulicaris Linnaeus were found in significantly greater numbers in the green LED trap than in the UV LED trap. The LED traps collected significantly fewer Culicoides than the standard CDC UV light-suction trap. Catches of Culicoides were reduced in LED traps when compared to the standard CDC UV trap, however, their reduced power requirement and small size fulfils a requirement for trapping in logistically challenging areas or where many

  6. Investigation on compression behaviour of highly compacted GMZ01 bentonite with suction and temperature control

    International Nuclear Information System (INIS)

    Ye, W.M.; Zhang, Y.W.; Chen, B.; Zheng, Z.J.; Chen, Y.G.; Cui, Y.J.

    2012-01-01

    Highlights: ► Heating induced volumetric change of GMZ01 bentonite depends on suction. ► Suction has significant influence on compressibility. ► Temperature has slight influence on compressibility. - Abstract: In this paper, an oedometer with suction and temperature control was developed. Mechanical compaction tests have been performed on the highly compacted GMZ01 bentonite, which has been recognized as potential buffer/backfill material for construction of Chinese high-level radioactive waste (HLW) geological repository, under conditions of suction ranging from 0 to 110 MPa, temperature from 20 to 80 °C and vertical pressure from 0.1 to 80 MPa. Based on the test results, suction and temperature effects on compressibility parameters are investigated. Results reveal that: (1) at high suctions, heating induced an expansion, while contraction is induced by heating at low suctions. The thermal expansion coefficient of GMZ01 bentonite measured is 1 × 10 −4 °C −1 ; (2) with increasing suction, the elastic compressibility κ and the plastic compressibility λ(s) of the highly compacted GMZ01 bentonite decrease, while the pre-consolidation pressure increases markedly; (3) with increasing temperature, the elastic compressibility of compacted GMZ01 bentonite changes insignificantly, while the plastic compressibility λ(s) slightly decreases and the yield surface tends to shrink.

  7. A Technique for Controlling Matric Suction on Filter Papers Used in ...

    African Journals Online (AJOL)

    Moist filter papers are widely usedfor seed gennination tests but their water confent and matric suction are not usually controlled. A technique for controlling filter paper matric suction is described and usedfor germination studies involving fresh and aged sorghum seed (Sorghummcolor (L) Moench). Filter papers wetted to ...

  8. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    Science.gov (United States)

    2010-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange (oxygenator...

  9. Development of two-stage compression heat pump for hot water supply in commercial use. Establishment of design method for water and air heat source system; Gyomuyo nidan asshukushiki kyuto heat pump no kaihatsu. Suinetguen oyobi kuki netsugen sytem no sekkei hoho no kakuritsu

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, H; Hashimoto, K; Saikawa, M; Iwatsubo, T; Mimaki, T [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1996-07-01

    The two-stage compression cascade heating heat pump cycle was devised for hot water supply in business use such as hotel and store use which allows hot water supply less in primary energy consumption than gas boilers, and higher in temperature than conventional heat pumps. This cycle heats water in cascade manner by two-stage compression using two compressors in both low- and high-stage refrigerant circuits, and two condensers different in condensation temperature (intermediate heat exchanger and condenser) to achieve higher hot water temperature and higher COP. For cost reduction, the new system design method was established which is possible to cope with conventional compressors such as screw and scroll ones with different theoretical suction volume for every one. System design parameters such as thermal output and COP of hot water supply were largely affected by theoretical suction volume ratio of low- and high-stage compressors dependent on combination of the compressors, and refrigerant condensing temperature in an intermediate heat exchanger as proper parameter. 4 refs., 17 figs., 13 tabs.

  10. Reliability and criterion-related validity testing (construct) of the Endotracheal Suction Assessment Tool (ESAT©).

    Science.gov (United States)

    Davies, Kylie; Bulsara, Max K; Ramelet, Anne-Sylvie; Monterosso, Leanne

    2018-05-01

    To establish criterion-related construct validity and test-retest reliability for the Endotracheal Suction Assessment Tool© (ESAT©). Endotracheal tube suction performed in children can significantly affect clinical stability. Previously identified clinical indicators for endotracheal tube suction were used as criteria when designing the ESAT©. Content validity was reported previously. The final stages of psychometric testing are presented. Observational testing was used to measure construct validity and determine whether the ESAT© could guide "inexperienced" paediatric intensive care nurses' decision-making regarding endotracheal tube suction. Test-retest reliability of the ESAT© was performed at two time points. The researchers and paediatric intensive care nurse "experts" developed 10 hypothetical clinical scenarios with predetermined endotracheal tube suction outcomes. "Experienced" (n = 12) and "inexperienced" (n = 14) paediatric intensive care nurses were presented with the scenarios and the ESAT© guiding decision-making about whether to perform endotracheal tube suction for each scenario. Outcomes were compared with those predetermined by the "experts" (n = 9). Test-retest reliability of the ESAT© was measured at two consecutive time points (4 weeks apart) with "experienced" and "inexperienced" paediatric intensive care nurses using the same scenarios and tool to guide decision-making. No differences were observed between endotracheal tube suction decisions made by "experts" (n = 9), "inexperienced" (n = 14) and "experienced" (n = 12) nurses confirming the tool's construct validity. No differences were observed between groups for endotracheal tube suction decisions at T1 and T2. Criterion-related construct validity and test-retest reliability of the ESAT© were demonstrated. Further testing is recommended to confirm reliability in the clinical setting with the "inexperienced" nurse to guide decision-making related to endotracheal tube

  11. Analisis Perubahan Nilai Suction Akibat Hujan Terhadap Kestabilan Lereng

    OpenAIRE

    Martini, Martini

    2009-01-01

    Infiltration of rainfall into slope will have an effect on to condition of slope hydrology and more specifically to characteristic of slope soils, for example pore water pressure value, level of saturation, weight contents of soil, shear strength of soil. Pore water pressure value at dry soil condition or wet condition called as with pore water pressure value negatife or value suction. This suction value will tend to declines and in the end becomes equal to zero or bigger than 0 ( positive po...

  12. Various Parameters of the Flowing Part of a Cylindrical Molecular Vacuum Pump Effecting on Its Characteristics

    Directory of Open Access Journals (Sweden)

    K. E. Demikhov

    2015-01-01

    Full Text Available In the context of modern industry the molecular vacuum pumps (MVP are widely used. The analyzed current market of vacuum technology enables drawing a conclusion that this equipment holds one of the leading positions among the high-vacuum facilities of pumping due to their advantages such as insensitivity to the atmosphere breakthrough, ability to pump out heavy gases quickly, rapid start-up time, and oil-free pumping.The earlier developed authors’ mathematical model and calculation program are used to assess the influence efficiency of the key geometrical parameters of flowing part of the cylindrical molecular pump on its main characteristics. The obtained dependences allow us to solve a relevant, but not completely resolved as yet problem of optimizing the high-vacuum pumping facilities in case of their operation in a wide range of pressures on the suction side.The paper presents graphs of the pumping speed and ratio of the cylindrical vacuum molecular pump pressures versus various parameters of the flowing part, such as the angle of inclination of the helix, the relative diameter and the number of helical starts. Conclusions are drawn.

  13. Investigation on compression behaviour of highly compacted GMZ01 bentonite with suction and temperature control

    Energy Technology Data Exchange (ETDEWEB)

    Ye, W.M., E-mail: ye_tju@tongji.edu.cn [Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092 (China); United Research Center for Urban Environment and Sustainable Development, The Ministry of Education, Shanghai 200092 (China); Zhang, Y.W.; Chen, B.; Zheng, Z.J.; Chen, Y.G. [Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092 (China); Cui, Y.J. [Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092 (China); Ecole des Ponts ParisTech, UR Navier/CERMES 77455 (France)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Heating induced volumetric change of GMZ01 bentonite depends on suction. Black-Right-Pointing-Pointer Suction has significant influence on compressibility. Black-Right-Pointing-Pointer Temperature has slight influence on compressibility. - Abstract: In this paper, an oedometer with suction and temperature control was developed. Mechanical compaction tests have been performed on the highly compacted GMZ01 bentonite, which has been recognized as potential buffer/backfill material for construction of Chinese high-level radioactive waste (HLW) geological repository, under conditions of suction ranging from 0 to 110 MPa, temperature from 20 to 80 Degree-Sign C and vertical pressure from 0.1 to 80 MPa. Based on the test results, suction and temperature effects on compressibility parameters are investigated. Results reveal that: (1) at high suctions, heating induced an expansion, while contraction is induced by heating at low suctions. The thermal expansion coefficient of GMZ01 bentonite measured is 1 Multiplication-Sign 10{sup -4} Degree-Sign C{sup -1}; (2) with increasing suction, the elastic compressibility {kappa} and the plastic compressibility {lambda}(s) of the highly compacted GMZ01 bentonite decrease, while the pre-consolidation pressure increases markedly; (3) with increasing temperature, the elastic compressibility of compacted GMZ01 bentonite changes insignificantly, while the plastic compressibility {lambda}(s) slightly decreases and the yield surface tends to shrink.

  14. Suction of MHD boundary layer flows

    International Nuclear Information System (INIS)

    Rao, B.N.

    1985-01-01

    The boundary layer growth with tensor electrical conductivity and the transpiration number has been examined using local nonsimilarity solutions method. It is found that suction will cause the increase in wall shearing stress and decrease in thicknesses of the boundary layer. (Auth.)

  15. Reactor coolant pump service life evaluation for current life cycle optimization and license renewal

    International Nuclear Information System (INIS)

    Doroshuk, B.W.; Berto, D.S.; Robles, M.

    1990-01-01

    This paper reports that as part of the plant life cycle management and license renewal program, Baltimore Gas and Electric Company (BG and E) has completed a service life evaluation of their reactor coolant pumps, funded jointly by EPRI and performed by ABB Combustion Engineering Nuclear Power. Two of the goals of the BG and E plant life cycle management and license renewal program, and of this current evaluation, are to identify actions which would optimize current plant operation, and ensure that license renewal remains a viable option. The reactor coolant pumps (RCPs) at BG and E's Calvert Cliffs Units 1 and 2 are Byron Jackson pumps with a diffuser and a single suction. This pump design is also used in many other nuclear plants. The RCP service life evaluation assessed the effect of all plausible age-related degradation mechanisms (ARDMs) on the RCP components. Cyclic fatigue and thermal embrittlement were two ARDMs identified as having a high potential to limit the service life of the pump case. The pump case is a primary pressure boundary component. Hence, ensuring its continued structural integrity is important

  16. Volume of blood suctioned during vacuum-assisted breast biopsy predicts later hematoma formation

    Directory of Open Access Journals (Sweden)

    Panopoulou Effrosyni

    2010-03-01

    Full Text Available Abstract Background To evaluate whether the volume of blood suctioned during vacuum-assisted breast biopsy (VABB is associated with hematoma formation and progression, patient's age and histology of the lesion. Findings 177 women underwent VABB according to standardized protocol. The volume of blood suctioned and hematoma formation were noted at the end of the procedure, as did the subsequent development and progression of hematoma. First- and second-order logistic regression was performed, where appropriate. Cases with hematoma presented with greater volume of blood suctioned (63.8 ± 44.7 cc vs. 17.2 ± 32.9 cc; p Conclusion The likelihood of hematoma is increasing along with increasing amount of blood suctioned, reaching a plateau approximately at 80 cc of blood lost.

  17. Pilot Study Comparing Closed Versus Open Tracheal Suctioning in Postoperative Neonates and Infants With Complex Congenital Heart Disease.

    Science.gov (United States)

    Tume, Lyvonne N; Baines, Paul B; Guerrero, Rafael; Hurley, Margaret A; Johnson, Robert; Kalantre, Atul; Ramaraj, Ram; Ritson, Paul C; Walsh, Laura; Arnold, Philip D

    2017-07-01

    To determine the hemodynamic effect of tracheal suction method in the first 36 hours after high-risk infant heart surgery on the PICU and to compare open and closed suctioning techniques. Pilot randomized crossover study. Single PICU in United Kingdom. Infants undergoing surgical palliation with Norwood Sano, modified Blalock-Taussig shunt, or pulmonary artery banding in the first 36 hours postoperatively. Infants were randomized to receive open or closed (in-line) tracheal suctioning either for their first or second study tracheal suction in the first 36 hours postoperatively. Twenty-four infants were enrolled over 18 months, 11 after modified Blalock-Taussig shunt, seven after Norwood Sano, and six after pulmonary artery banding. Thirteen patients received the open suction method first followed by the closed suction method second, and 11 patients received the closed suction method first followed by the open suction method second in the first 36 hours after their surgery. There were statistically significant larger changes in heart rate (p = 0.002), systolic blood pressure (p = 0.022), diastolic blood pressure (p = 0.009), mean blood pressure (p = 0.007), and arterial saturation (p = 0.040) using the open suction method, compared with closed suctioning, although none were clinically significant (defined as requiring any intervention). There were no clinically significant differences between closed and open tracheal suction methods; however, there were statistically significant greater changes in some hemodynamic variables with open tracheal suctioning, suggesting that closed technique may be safer in children with more precarious physiology.

  18. Rekonstruksi pada Perforasi Palatum Akibat Pneggunaan Gigi Tiruan Lengkap Rahang Atas dengan Suction Cup

    Directory of Open Access Journals (Sweden)

    Cristiani Nadya Pramasari

    2012-12-01

    Full Text Available Latar belakang. Pemasangan suction cup pada gigi tiruan lengkap rahang atas merupakan salah satu cara untuk meningkatkan referensi. Kondisi vakum oleh karena suction cup ini dalam waktu jangka panjang dan tidak terkontrol mengakibatkan nekrosis jaringan yaitu adanya perforasi palatum. Tujuan. Melaporkan rekonstruksi penutupan perforasi palatum sebagai komplikasi penggunaan gigi tiruan lengkap rahang atas dengan suction cup. Laporan Kasus. Pada tanggal 11 September 2012 seorang pria berusia 64 tahun datang ke Poliklinik Bedah Mulut RSUP dr. Sardjito Yogyakarta dengan keluhan terdapat lubang pada langit-langit. Pasien menggunakan gigi palsu buatan tukang gigi dengan perekat berbahan karet pada langit-langit selama 5 tahun. Selama penggunaan gigi palsu pasien sering mengalami sakit dan pembengkakan di langit-langit sampai keluar nanah dan akhirnya terbentuk lubang sehingga jika minum air keluar dari hidung. Pemeriksaan rontgen oklusal rahang atas tampak adanya resorbsi regio palatum durum. Rekonstruksi menggunakan teknik push back modifikasi dilakukan untuk penutupan perforasi palatum di bawah anestesi umum. Kesimpulan. Suction cup pada gigi tiruan lengkap rahang atas mengakibatkan kerusakan jaringan lunak dan jaringan keras rongga mulut. Perforasi palatum yang diakibatkan oleh suction cup ini dapat dilakukan rekonstruksi dengan teknik push back dengan hasil yang cukup optimal.   Background. Suction cups are used to get retention of the complete dentures. The uncontrolled constant vacuum created by the suction cup induces necrosis of tissues and perforation ofpalate. Objective. To report reconstruction for palatal perforation closure as a complication due to prolonged use of maxillary denture with suction cup. Case Report. A 64 years old male patient came to the Department of Oral Surgery, Sardjito General Hospital Yogyakarta on September 11, 2012 with the complaint of hole in his palate. He was wearing dentures for the past 5 years. He also

  19. MAXIMUM AIR SUCTION INTO HORIZONTAL OPEN ENDED CYLINDRICAL LOUVERED PIPE

    Directory of Open Access Journals (Sweden)

    SAMEER RANJAN SAHU

    2017-02-01

    Full Text Available The main approach behind the present numerical investigation is to estimate the mass flow rate of air sucked into a horizontal open-ended louvered pipe from the surrounding atmosphere. The present numerical investigation has been performed by solving the conservation equations for mass, momentum and energy along with two equation based k-ɛ model for a louvered horizontal cylindrical pipe by finite volume method. It has been found from the numerical investigation that mass suction rate of air into the pipe increases with increase in louvered opening area and the number of nozzles used. Keeping other parameters fixed, for a given mass flow rate there exists an optimum protrusion of nozzle for highest mass suction into the pipe. It was also found from the numerical investigation that increasing the pipe diameter the suction mass flow rate of air was increased.

  20. Spine immobilization apparatus

    Science.gov (United States)

    Lambson, K. H.; Vykukal, H. C. (Inventor)

    1981-01-01

    The apparatus makes use of a normally flat, flexible bladder filled with beads or micro-balloons that form a rigid mass when the pressure within the bladder is decreased below ambient through the use of a suction pump so that the bladder can be conformed to the torso of the victim and provide the desired restraint. The bladder is strapped to the victim prior to being rigidified by an arrangement of straps which avoid the stomach area. The bladder is adapted to be secured to a rigid support, i.e., a rescue chair, so as to enable removal of a victim after the bladder has been made rigid. A double sealing connector is used to connect the bladder to the suction pump and a control valve is employed to vary the pressure within the bladder so as to soften and harden the bladder as desired.

  1. Part-load operation of the boiler feedwater pumps for the new French PWR 1400 MW nuclear plants - a challenge for the designer

    International Nuclear Information System (INIS)

    Martin, R.; Canavelis, R.; Guilloiseau, P.

    1988-01-01

    The Boiler feedwater pumps in Electricite de France Power Stations have to work reliably for all flow rates between 33% and 134% of the flow corresponding to the best efficiency point (Q BEP ). Under transient conditions associated with load changing these limits increase to 33% to 147% Q BEP . Due to the high specific power of these pumps, the operating conditions heavily influence the hydraulic and mechanical dimensioning. This paper presents some particular aspects of their design and test results obtained on a pump model as well as on a full scale prototype concerning suction performance, head capacity curve stability, pressure pulsations and structural excitations. (author)

  2. Bernoulli Suction Effect on Soap Bubble Blowing?

    Science.gov (United States)

    Davidson, John; Ryu, Sangjin

    2015-11-01

    As a model system for thin-film bubble with two gas-liquid interfaces, we experimentally investigated the pinch-off of soap bubble blowing. Using the lab-built bubble blower and high-speed videography, we have found that the scaling law exponent of soap bubble pinch-off is 2/3, which is similar to that of soap film bridge. Because air flowed through the decreasing neck of soap film tube, we studied possible Bernoulli suction effect on soap bubble pinch-off by evaluating the Reynolds number of airflow. Image processing was utilized to calculate approximate volume of growing soap film tube and the volume flow rate of the airflow, and the Reynolds number was estimated to be 800-3200. This result suggests that soap bubbling may involve the Bernoulli suction effect.

  3. Energy system investment model incorporating heat pumps with thermal storage in buildings and buffer tanks

    International Nuclear Information System (INIS)

    Hedegaard, Karsten; Balyk, Olexandr

    2013-01-01

    Individual compression heat pumps constitute a potentially valuable resource in supporting wind power integration due to their economic competitiveness and possibilities for flexible operation. When analysing the system benefits of flexible heat pump operation, effects on investments should be taken into account. In this study, we present a model that facilitates analysing individual heat pumps and complementing heat storages in integration with the energy system, while optimising both investments and operation. The model incorporates thermal building dynamics and covers various heat storage options: passive heat storage in the building structure via radiator heating, active heat storage in concrete floors via floor heating, and use of thermal storage tanks for space heating and hot water. It is shown that the model is well qualified for analysing possibilities and system benefits of operating heat pumps flexibly. This includes prioritising heat pump operation for hours with low marginal electricity production costs, and peak load shaving resulting in a reduced need for peak and reserve capacity investments. - Highlights: • Model optimising heat pumps and heat storages in integration with the energy system. • Optimisation of both energy system investments and operation. • Heat storage in building structure and thermal storage tanks included. • Model well qualified for analysing system benefits of flexible heat pump operation. • Covers peak load shaving and operation prioritised for low electricity prices

  4. From medicine to natural philosophy: Francis Hauksbee's way to the air-pump.

    Science.gov (United States)

    Brundtland, Terje

    2008-06-01

    Francis Hauksbee (1660-1713) is well known for his double-barrelled air-pump. However, the origin of this pump, and Hauksbee's background, are often described as a mystery. This text seeks to dispel the riddle. It is argued that Hauksbee's competence as an exceptional maker of air-pumps was developed between 1699 and 1703 as a result of his experiences with the construction, manufacturing and sale of cupping-glasses. His cupping utensils embodied a new design, where syringes were used to evacuate the glasses, instead of the traditional way by fire or mouth suction. These syringes, which in fact were small air-pumps, were perfected between 1699 and 1701. A larger syringe, introduced in 1701, served as a transition from the cupping-syringe to his first air-pump for use in natural philosophy. This syringe was described as a 'combined engine', which could serve as an air-pump, a condensing engine and a syringe for injecting air, wax or mercury into pathological specimens. Hauksbee's first air-pump was a single-barrelled model introduced in 1702, based on the combined engine. Its various features, such as easy and convenient leak-tightening, exact pressure measurements by an in-built barometer and an air-inlet function for readmission of air into the receiver, are discussed. Finally, it is shown that these activities gave Hauksbee the reputation of being an outstanding instrument-maker, years before the double-barrelled air-pump was in sight.

  5. Hydrodynamics of suction feeding in fish

    NARCIS (Netherlands)

    Muller, M.

    1983-01-01

    1. Suction feeding is the dominant way to obtain food in teleosts. Its high demands on structures due to the required velocities and forces leads to the expectation that a biophysical analysis will aid to reveal the adaptive significance of head and body structures related to this

  6. Suction forces generated by passive bile bag drainage on a model of post-subdural hematoma evacuation.

    Science.gov (United States)

    Tenny, Steven O; Thorell, William E

    2018-05-05

    Passive drainage systems are commonly used after subdural hematoma evacuation but there is a dearth of published data regarding the suction forces created. We set out to quantify the suction forces generated by a passive drainage system. We created a model of passive drainage after subdural hematoma evacuation. We measured the maximum suction force generated with a bile bag drain for both empty drain tubing and fluid-filled drain tube causing a siphoning effect. We took measurements at varying heights of the bile bag to analyze if bile bag height changed suction forces generated. An empty bile bag with no fluid in the drainage tube connected to a rigid, fluid-filled model creates minimal suction force of 0.9 mmHg (95% CI 0.64-1.16 mmHg). When fluid fills the drain tubing, a siphoning effect is created and can generate suction forces ranging from 18.7 to 30.6 mmHg depending on the relative position of the bile bag and filled amount of the bile bag. The suction forces generated are statistically different if the bile bag is 50 cm below, level with or 50 cm above the experimental model. Passive bile bag drainage does not generate significant suction on a fluid-filled rigid model if the drain tubing is empty. If fluid fills the drain tubing then siphoning occurs and can increase the suction force of a passive bile bag drainage system to levels comparable to partially filled Jackson-Pratt bulb drainage.

  7. Study on the performance improvement of multiblade fans. Effects of suction cones; Tayoku fan no seino kaizen ni kansuru kenkyu. Suction cone no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kuratani, F.; Ogawa, T. [Hyogo University of Teacher Education, Hyogo (Japan); Yamamoto, S.

    1999-07-25

    In order to improve the performance of a multiblade fan, the effects of three types of suction cones of the fan casing on the fan efficiency and noise are investigated experimentally. The first type of the suction cone is the insertion type, which is inserted into the inside of the fan impeller. The second type is the extrusion type, which extrudes outside from the casing surface. The third type is the combination type of two types. The results of those three types are compared with those of the commonly used suction cone. The followings are made clear: (1) The insertion type and the extrusion type are effective in improving the efficiency and reducing noise. (2) The optimal lengths of the insertion and the extrusion exist. (3) The combination type is more effective in improving the efficiency. (4) The combination type with the skewed cutoff of the fan casing shows the best effect. (author)

  8. Vacuum pumping by the halo plasma

    International Nuclear Information System (INIS)

    Barr, W.L.

    1985-01-01

    An estimate is made of the effective vacuum pumping speed of the halo plasma in a tandem mirror fusion reactor, and it is shown that, if the electron temperature and line density are great enough, the halo can be a very good vacuum pump. One can probably obtain the required density by recycling the ions at the halo dumps. An array of small venting ports in the dump plates allows local variation of the recycle fraction and local removal of the gas at a conveniently high pressure. This vented-port concept could introduce more flexibility in the design of pumped limiters for tokamaks

  9. Characterization of zebrafish larvae suction feeding flow using μPIV and optical coherence tomography

    OpenAIRE

    Pekkan, Kerem; Uslu, Fazıl E.; Chang, Brain; Mani, Karthick; Chen, Chia-Yuan; Holzman, Roi

    2016-01-01

    The hydrodynamics of suction feeding is critical for the survival of fish larvae; failure to capture food during the onset of autonomous feeding can rapidly lead to starvation and mortality. Fluid mechanics experiments that investigate the suction feeding of suspended particles are limited to adult fishes, which operate at large Reynolds numbers. This manuscript presents the first literature results in which the external velocity fields generated during suction feeding of early zebrafish larv...

  10. Effects of Lavender Inhalant on the Pain during Endotracheal Suctioning in Intensive Care Unit Patients

    Directory of Open Access Journals (Sweden)

    M. Taheri Rezgh Abadi

    2017-09-01

    Full Text Available Aims: Patients undergoing artificial ventilation require tracheal tube suction because of inability to clear their effective airways, which is usually a painful process for the patients. The aim of this study was to investigate the effect of spike lavender’s inhalant on pain during tracheal tube suctioning in ICU intubated patients. Materials & Methods: In this double-blinded randomized clinical trial, 60 intubated patients hospitalized in ICU of Shahid Modarres Hospital of Kashmar City, Iran, in 2017 were selected by available and simple sampling method, and were randomly divided into 2 control and case groups (each 30 individuals. Before the standard suctioning process, the test group patients received inhalant of 2% spike lavender for 5 minutes and the control group received inhalant of distilled water. The level of pain was recorded before and during tracheal tube suctioning. Data were analyzed by SPSS 16 software using independent T, paired T, Fisher and Mann-Whitney U tests. Findings: There was no significant difference in pain score before tracheal tube suction between 2 groups (p>0.05. However, there were significant differences between the level of pain during tracheal tube suctioning and the pain was increased in both groups, but this increase was significantly higher in the control group (p<0.001. Conclusion: Spike lavender’s inhalant is effective on pain reduction during suctioning process of ICU intubated patients.

  11. Recirculation pump suction line 2.8% break integral test at ROSA-III with HPCS failure, RUN 984

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro; Anoda, Yoshinari; Tasaka, Kanji; Kumamaru, Hiroshige; Nakamura, Hideo; Yonomoto, Taisuke; Murata, Hideo; Shiba, Masayoshi

    1984-06-01

    This report presents the experimental data of 2.8% suction line break test RUN 984 at ROSA-III, which was conducted as one of counterpart tests to FIST program sponsored by GE, EPRI and USNRC. The similarity study between the ROSA-III and FIST tests is on the way. The report also presents the information on the ROSA-III test facility, experiment results and the effects of the ADS flow rate and the MSIV trip level comparing with the previously conducted ROSA-III small break tests, RUNs 920 and 922. Major conclusions obtained are as follows. (1) Change of the MSIV trip level from L2 to L1 gives delay of MSIV closure and longer actuation of pressure control system in a small break LOCA. (2) Larger ADS flow gives faster depressurization rate and earlier ECCS actuation, which results in shorter fuel rod dryout period and lower PCT. (author)

  12. Device for the prehension by means of suction cups

    International Nuclear Information System (INIS)

    Gabillet, Maurice

    1980-01-01

    The difficulties encountered while utilising suction-cups, are mainly caused by the skirts. The skirts are more or less adaptable to the surface of the objects to be handled. The skirt of the device presented, is made out of a round supple elastic bag containing solid particles. By creating a vacuum in the bag, the particles become a solid entity. The bag filled with the particles becomes rigid and can take exactly the shape of the object to be lifted. By creating a second vacuum in the axis of the bag, the object can be lifted. Several suction-cups can be used simultaneously

  13. Effect of gas quantity on two-phase flow characteristics of a mixed-flow pump

    Directory of Open Access Journals (Sweden)

    Qiang Fu

    2016-04-01

    Full Text Available The inlet gas quantity has a great influence on the performance and inner flow characteristics of a mixed-flow pump. In this article, both numerical and experimental methods are used to carry out this research work. The effects under the steady gas volume fraction state and the transient gas quantity variation process on the mixed-flow pump are investigated and compared in detail. It could be concluded that the head of the mixed-flow pump shows slight decline at the low gas volume fraction state, while it decreases sharply at the high gas volume fraction state and then decreases with the increasing gas quantity. There is an obvious asymmetric blade vapor density on the blade suction side under each cavitation state. The cavities can be weakened obviously by increasing the inlet gas volume fraction within a certain range. It has little influence on the internal unsteady flow of the mixed-flow pump when the gas volume fraction is less than 10%, but the pump starts to operate with a great unsteady characteristic when the inlet gas volume fraction increases to 15%.

  14. Electricity Market Optimization of Heat Pump Portfolio

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Andersen, Palle; Pedersen, Tom S.

    2013-01-01

    We consider a portfolio of domestic heat pumps controlled by an aggregator. The aggregator is able to adjust the consumption of the heat pumps without affecting the comfort in the houses and uses this ability to shift the main consumption to hours with low electricity prices. Further......, the aggregator is able to place upward and downward regulating bids in the regulating power market based on the consumption flexibility. A simulation is carried out based on data from a Danish domestic heat pump project, historical spot prices, regulating power prices, and spot price predictions. The simulations...

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

    International Nuclear Information System (INIS)

    Hedegaard, Karsten; Münster, Marie

    2013-01-01

    Highlights: • Individual heat pumps can significantly support the integration of wind power. • The heat pumps significantly reduce fuel consumption, CO 2 emissions, and costs. • Heat storages for the heat pumps can provide only moderate system benefits. • Main benefit of flexible heat pump operation is a lower peak/reserve capacity need. • Socio-economic feasibility only identified for some heat storages to some extent. - Abstract: 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 an energy system model that optimises both investments and operation, and covers various heat storage options. The Danish energy system by 2030 with around 50–60% wind power is used as a case study. Results show that the heat pumps, even without flexible operation, can contribute significantly to facilitating larger wind power investments and reducing system costs, fuel consumption, and CO 2 emissions. Investments in heat storages can provide only moderate system benefits in these respects. The main benefit of the flexible heat pump operation is a reduced need for peak/reserve capacity, which is also crucial for the feasibility of the heat storages. Socio-economic feasibility is identified for control equipment enabling intelligent heat storage in the building structure and in existing hot water tanks. In contrast, investments in new heat accumulation tanks are not found competitive

  16. Corner Separation Control by Boundary Layer Suction Applied to a Highly Loaded Axial Compressor Cascade

    Directory of Open Access Journals (Sweden)

    Yangwei Liu

    2014-11-01

    Full Text Available Control of corner separation has attracted much interest due to its improvement of performance and energy utilization in turbomachinery. Numerical studies have been performed under both design and off-design flow conditions to investigate the effects of boundary layer suction (BLS on corner separation in a highly loaded compressor cascade. Two new BLS slot configurations are proposed and a total of five suction slot configurations were studied and compared. Averaged static pressure rise, exit loss coefficient, passage blockage and flow turning angle have been given and compared systematically over a range of operation incidence angles. Distributions of significant loss removal, blade loading, exit deviation and total pressure loss at 3 degree and 7 degree incidence have also been studied. Under the same suction mass flows of 0.7% of the inlet mass flows, the pitchwise suction slot on the endwall shows a better optimal performance over the whole operation incidence among single suction slots. By using of the new proposed compound slot configuration with one spanwise slot on the blade suction side and one pitchwise slot on the endwall, the maximum reduction of total pressure loss at 7 degree incidence can be 39.4%.

  17. TFTR ultrahigh-vacuum pumping system incorporating mercury diffusion pumps

    International Nuclear Information System (INIS)

    Sink, D.A.; Sniderman, M.

    1976-06-01

    The TFTR vacuum vessel will have a system of four 61 cm diameter mercury diffusion pumps to provide a base pressure in the 10 -8 to 10 -9 Torr range as well as a low impurity level within the vessel. The system, called the Torus Vacuum Pumping System (TVPS), will be employed with the aid of an occasional 250 0 C bakeout in situ as well as periodic applications of aggressive discharge cleaning. The TVPS is an ultrahigh-vacuum (UHV) system using no elastomers as well as being a closed system with respect to tritium or any tritiated gases. The backing system employing approximately 75 all-metal isolation valves is designed with the features of redundancy and flexibility employed in a variety of ways to meet the fundamental requirements and functions enumerated for the TVPS. Since the design, is one which is a modification of the conceptual design of the TVPS, those features which have changed are discussed. Calculations are presented for the major performance parameters anticipated for the TVPS and include conductances, effective pumping speeds, base pressures, operating parameters, getter pump parameters, and calculations of time constants associated with leak checking. Modifications in the vacuum pumping system for the guard regions on the twelve bellows sections are presented so that it is compatible with the main TVPS. The bellows pumping system consists of a mechanical pump unit, a zirconium aluminum getter pump unit and a residual gas analyzer. The control and management of the TVPS is described with particular attention given to providing both manual and automatic control at a local station and at the TFTR Central Control. Such operations as testing, maintenance, leak checking, startup, bakeout, and various other operations are considered in some detail. Various aspects related to normal pulsing, discharge cleaning, non-tritium operations and tritium operations are also taken into consideration. A cost estimate is presented

  18. Functional morphology of the feeding apparatus, feeding constraints, and suction performance in the nurse shark Ginglymostoma cirratum.

    Science.gov (United States)

    Motta, Philip J; Hueter, Robert E; Tricas, Timothy C; Summers, Adam P; Huber, Daniel R; Lowry, Dayv; Mara, Kyle R; Matott, Michael P; Whitenack, Lisa B; Wintzer, Alpa P

    2008-09-01

    The nurse shark, Ginglymostoma cirratum, is an obligate suction feeder that preys on benthic invertebrates and fish. Its cranial morphology exhibits a suite of structural and functional modifications that facilitate this mode of prey capture. During suction-feeding, subambient pressure is generated by the ventral expansion of the hyoid apparatus and the floor of its buccopharyngeal cavity. As in suction-feeding bony fishes, the nurse shark exhibits expansive, compressive, and recovery kinematic phases that produce posterior-directed water flow through the buccopharyngeal cavity. However, there is generally neither a preparatory phase nor cranial elevation. Suction is generated by the rapid depression of the buccopharyngeal floor by the coracoarcualis, coracohyoideus, and coracobranchiales muscles. Because the hyoid arch of G. cirratum is loosely connected to the mandible, contraction of the rectus cervicis muscle group can greatly depress the floor of the buccopharyngeal cavity below the depressed mandible, resulting in large volumetric expansion. Suction pressures in the nurse shark vary greatly, but include the greatest subambient pressures reported for an aquatic-feeding vertebrate. Maximum suction pressure does not appear to be related to shark size, but is correlated with the rate of buccopharyngeal expansion. As in suction-feeding bony fishes, suction in the nurse shark is only effective within approximately 3 cm in front of the mouth. The foraging behavior of this shark is most likely constrained to ambushing or stalking due to the exponential decay of effective suction in front of the mouth. Prey capture may be facilitated by foraging within reef confines and close to the substrate, which can enhance the effective suction distance, or by foraging at night when it can more closely approach prey.

  19. Performance of high-area-ratio annular dump diffuser using suction-stabilized-vortex flow control

    Science.gov (United States)

    Juhasz, A. J.; Smith, J. M.

    1977-01-01

    A short annular dump diffuser having a geometry conductive to formation of suction stabilized toroidal vortices in the region of abrupt area change was tested. The overall diffuser area ratio was 4.0 and the length to inlet height ratio was 2.0. Performance data were obtained at near ambient temperature and pressure for inlet Mach numbers of 0.18 and 0.30 with suction rates ranging from 0 to 18 percent of total inlet mass flowrate. Results show that the exit velocity profile could be readily biased toward either wall by adjustment of inner and outer wall suction rates. Symmetric exit velocity profiles were inherently unstable with a tendency to revert to a hub or tip bias. Diffuser effectiveness was increased from about 38 percent without suction to over 85 percent at a total suction rate of 10 to 12 percent. At the same time diffuser total pressure loss was reduced from 3.1 percent to 1.1 percent at an inlet Mach number of 0.3.

  20. Characterization of zebrafish larvae suction feeding flow using μPIV and optical coherence tomography

    Science.gov (United States)

    Pekkan, Kerem; Chang, Brian; Uslu, Fazil; Mani, Karthick; Chen, Chia-Yuan; Holzman, Roi

    2016-07-01

    The hydrodynamics of suction feeding is critical for the survival of fish larvae; failure to capture food during the onset of autonomous feeding can rapidly lead to starvation and mortality. Fluid mechanics experiments that investigate the suction feeding of suspended particles are limited to adult fishes, which operate at large Reynolds numbers. This manuscript presents the first literature results in which the external velocity fields generated during suction feeding of early zebrafish larvae (2500-20,000 μm total length) are reported using time-resolved microscopic particle image velocimetry. For the larval stages studied, the maximum peak suction velocity of the inflow bolus is measured at a finite distance from the mouth tip and ranges from 1 to 8 mm/s. The average pressure gradient and the velocity profile proximal to the buccal (mouth) cavity are calculated, and two distinct trends are identified. External recirculation regions and reverse flow feeding cycles are also observed and quantified. One of the unresolved questions in fish suction feeding is the shape and dynamics of the buccal cavity during suction feeding; optical coherence tomography imaging is found to be useful for reconstructing the mouth kinematics. The projected area of the mouth cavity during the feeding cycle varies up to 160 and 22 % for the transverse and mid-sagittal planes, respectively. These findings can inspire novel hydrodynamically efficient biomedical and microfluidic devices.

  1. New approach to the suction force at the leading edge of a profile with zero thickness

    NARCIS (Netherlands)

    Sparenberg, JA; de Jager, EM

    2004-01-01

    This paper considers the suction force at the leading edge of a profile with zero thickness in an incompressible and inviscid fluid flow. The theory is linear, and the approach to the suction force is from the innerside of the profile. It is shown that the suction force can be considered as an

  2. Pad for holding a load against a surface by suction

    International Nuclear Information System (INIS)

    Farmer, R.C.; Goldsmith, H.A.; Proudlove, M.J.

    1981-01-01

    This invention concerns suction pads for supporting loads. Specifically, the suction pad is part of a pair of pads located at the ends of a bridge forming a vehicle for transporting instruments for the non-destructive testing of a large vessel intended to contain a fuel assembly for a nuclear reactor immersed in a liquid metal coolant. For example, the vehicle is of the type described in the French patent application filed this day under the heading 'Vehicle for transporting instruments for testing against a wall' [fr

  3. 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...... an energy system model that optimises both investments and operation, and covers various heat storage options. The Danish energy system by 2030 with around 50–60% wind power is used as a case study. Results show that the heat pumps, even without flexible operation, can contribute significantly...... to facilitating larger wind power investments and reducing system costs, fuel consumption, and CO2 emissions. Investments in heat storages can provide only moderate system benefits in these respects. The main benefit of the flexible heat pump operation is a reduced need for peak/reserve capacity, which is also...

  4. INCOMPRESSIBLE LAMINAR BOUNDARY LAYER CONTROL BY BLOWING AND SUCTION

    Directory of Open Access Journals (Sweden)

    AZZEDINE NAHOUI

    2013-12-01

    Full Text Available A two-dimensional incompressible laminar boundary layer and its control using blowing and suction over a flat plate and around the NACA 0012 and 661012 profiles, is studied numerically. The study is based on the Prandtl boundary layer model using the finite differences method and the Crank-Nicolson scheme. The velocity distribution, the boundary layer thickness and the friction coefficient, are determined and presented with and without control. The application of the control technique, has demonstrated its positive effect on the transition point and the friction coefficient. Both control procedures are compared for different lengths, speeds and angles of blowing and suction.

  5. Using the motor to monitor pump conditions

    International Nuclear Information System (INIS)

    Casada, D.

    1996-01-01

    When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented

  6. Using the motor to monitor pump conditions

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

    When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented.

  7. Reliable site for suction blister induction and harvesting

    Directory of Open Access Journals (Sweden)

    Laxmisha Chandrashekar

    2005-01-01

    Full Text Available Background: Suction blister grafting is a useful modality of treatment of patients with resistant and stable vitiligo. However, there have been no detailed studies to find out the best donor site for blister formation. Methods: The study was conducted between the period of October 2004 and February 2005 in the dermatology department at a tertiary care center. Nine patients with vitiligo (focal vitiligo, 3; mucosal vitiligo, 2; acrofacial vitiligo, 2; vitiligo vulgaris, 1; and segmental vitiligo, 1 were selected for blister harvesting and grafting. The blisters were raised using the method described by Gupta et al. Results: Suction blisters were attempted to be raised at 52 sites, but only 38 blisters could be raised, 24 complete and 14 incomplete. Blisters were raised in all the three cases on the flexor aspect of the arm (100%, 15 of 17 cases (88.2% on the flexor aspect of the forearm, 4 of 5 cases (80% on the abdomen, 11 of 16 cases (68.7% on the anterolateral thigh, and less frequently over leg or foot. Complete blisters were formed in 13/15 cases (86.6% on the flexor aspect of the forearm, 6/11 cases (54.5% on the anterolateral thigh, and in all cases over leg. Conclusion: The flexor aspect of the forearm is a good site for suction blister harvesting.

  8. Submersible canned motor transfer pump

    International Nuclear Information System (INIS)

    Guardiani, R.F.; Pollick, R.D.; Nyilas, C.P.; Denmeade, T.J.

    1997-01-01

    A transfer pump is described which is used in a waste tank for transferring high-level radioactive liquid waste from a waste tank and having a column assembly, a canned electric motor means, and an impeller assembly with an upper impeller and a lower impeller connected to a shaft of a rotor assembly. The column assembly locates a motor housing with the electric motor means adjacent to the impeller assembly which creates an hydraulic head, and which forces the liquid waste, into the motor housing to cool the electric motor means and to cool and/or lubricate the radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the upper impeller and electric motor means grind large particles in the liquid waste flow. Slots in the static bearing member of the radial bearing assemblies further grind down the solid waste particles so that only particles smaller than the clearances in the system can pass there through, thereby resisting damage to and the interruption of the operation of the transfer pump. The column assembly is modular so that sections can be easily assembled, disassembled and/or removed. A second embodiment employs a stator jacket which provides an alternate means for cooling the electric motor means and lubricating and/or cooling the bearing assemblies, and a third embodiment employs a variable level suction device which allows liquid waste to be drawn into the transfer pump from varying and discrete levels in the waste tank. 17 figs

  9. Evaluation of Failed Crane Chempumps Used During Salt Well Pumping

    International Nuclear Information System (INIS)

    ELSEN, J.J.

    2000-01-01

    The Interim Stabilization Project is responsible for removing pumpable interstitial liquid from remaining single shelled tanks and transferring the waste to safer double-shelled tanks. This waste transfer is conducted by installing a saltwell pumping system within the designated single shell tank, and transferring the waste to double shelled tank using approved transfer lines. The saltwell pumping system is placed within a saltwell screen installed into the tank waste, the screen is designed to allow gravity flow of liquid into the screen and prevent solids from entering the pumping system. A foot valve consisting of a venturi jet and nozzle creates a suction, picking up waste at an equal rate as the out flow transfer rate of the saltwell system. A centrifugal pump is used to create the motive force across the eductor and drive the waste through the associated system piping and transfer lines leading to the double shelled tanks. The centrifugal pump that has typically been used in the saltwell pumping system installations is the Crane Chempump, model GA-1 1/2 K with 4 3/4 inch impeller. The following evaluation is not intended to be an all inclusive analysis of the operation of a saltwell system and associated pump. This evaluation will detail some of the noted failures in specific saltwell systems and document those findings. Due to the large number of saltwell systems installed over the duration of the Stabilization Project, only those saltwell systems installed over the last two years within S, SX, U, A and AX tank farms, shall be included in this evaluation. After identification of the pump failures mechanism, recommendations shall be identified to address potential means of improving overall operational efficiency and reducing overall equipment failures

  10. Flexibility in flood management design: proactive planning under uncertainty

    Science.gov (United States)

    Smet, K.; de Neufville, R.; van der Vlist, M.

    2016-12-01

    This paper presents a value-enhancing approach for proactive planning and design of long-lived flood management infrastructure given uncertain future flooding threats. Designing infrastructure that can be adapted over time is a method to safeguard the efficacy of current design decisions given future uncertainties. We explore the value of embedding "options" in a physical structure, where an option is the right but not the obligation to do something at a later date (e.g. over-dimensioning a floodwall foundation now facilitates a future height addition in response to observed increases in sea level; building extra pump bays in a drainage pumping station enables the easy addition of pumping capacity whenever increased precipitation warrants an expansion.) The proposed approach couples a simulation model that captures future climate induced changes to the hydrologic operating environment of a structure, with an economic model that estimates the lifetime economic performance of alternative investment strategies. The economic model uses Real "In" Options analysis, a type of cash flow analysis that quantifies the implicit value of options and the flexibility they provide. We demonstrate the approach using replacement planning for the multi-functional pumping station IJmuiden on the North Sea Canal in the Netherlands. The analysis models flexibility in design decisions, varying the size and specific options included in the new structure. Results indicate that the incorporation of options within the structural design has the potential to improve its economic performance, as compared to more traditional, "build it once and build it big" designs where flexibility is not an explicit design criterion. The added value resulting from the incorporation of flexibility varies with the range of future conditions considered, and the specific options examined. This approach could be applied to explore investment strategies for the design of other flood management structures, as well

  11. Prospective randomized trial compares suction versus water seal for air leaks.

    Science.gov (United States)

    Cerfolio, R J; Bass, C; Katholi, C R

    2001-05-01

    Surgeons treat air leaks differently. Our goal was to evaluate whether it is better to place chest tubes on suction or water seal for stopping air leaks after pulmonary surgery. A second goal was to evaluate a new classification system for air leaks that we developed. Patients were prospectively randomized before surgery to receive suction or water seal to their chest tubes on postoperative day (POD) #2. Air leaks were described and quantified daily by a classification system and a leak meter. The air-leak meter scored leaks from 1 (least) to 7 (greatest). The group randomized to water seal stayed on water seal unless a pneumothorax developed. On POD #2, 33 of 140 patients had an air leak. Eighteen patients had been preoperatively randomized to water seal and 15 to suction. Air leaks resolved in 12 (67%) of the water seal patients by the morning of POD #3. All 6 patients whose air leak did not stop had a leak that was 4/7 or greater (p leak meter. Of the 15 patients randomized to suction, only 1 patient's air leak (7%) resolved by the morning of POD #3. The randomization aspect of the trial was ended and statistical analysis showed water seal was superior (p = 0.001). The remaining 14 patients were then placed to water seal and by the morning of POD #4, 13 patients' leaks had stopped. Of the 32 total patients placed to seal, 7 (22%) developed a pneumothorax and 6 of these 7 patients had leaks that were 4/7 or greater (p = 0.001). Placing chest tubes on water seal seems superior to wall suction for stopping air leaks after pulmonary resection. However, water seal does not stop expiratory leaks that are 4/7 or greater. Pneumothorax may occur when chest tubes are placed on seal with leaks this large.

  12. Necessity of suction drains in gynecomastia surgery.

    Science.gov (United States)

    Keskin, Mustafa; Sutcu, Mustafa; Cigsar, Bulent; Karacaoglan, Naci

    2014-05-01

    The aim of gynecomastia surgery is to restore a normal chest contour with minimal signs of breast surgery. The authors examine the rate of complications in gynecomastia surgery when no closed-suction drains are placed. One hundred thirty-eight consecutive male patients who underwent gynecomastia surgery without drains were retrospectively analyzed to determine whether the absence of drains adversely affected patient outcomes. Patients were managed by ultrasonic-assisted liposuction both with and without the pull-through technique. The mean age of the patients was 29 years, and the mean volume of breast tissue aspirated was 350 mL per beast. Pull-through was needed in 23 cases. There was only 1 postoperative hematoma. These results are comparable with previously published data for gynecomastia surgery in which drains were placed, suggesting that the absence of drains does not adversely affect postoperative recovery. Routine closed-suction drainage after gynecomastia surgery is unnecessary, and it may be appropriate to omit drains after gynecomastia surgery.

  13. CFD Analysis of a Centrifugal Fan for Performance Enhancement using Converging Boundary Layer Suction Slots

    OpenAIRE

    K. Vasudeva Karanth; N. Yagnesh Sharma

    2009-01-01

    Generally flow behavior in centrifugal fan is observed to be in a state of instability with flow separation zones on suction surface as well as near the front shroud. Overall performance of the diffusion process in a centrifugal fan could be enhanced by judiciously introducing the boundary layer suction slots. With easy accessibility of CFD as an analytical tool, an extensive numerical whole field analysis of the effect of boundary layer suction slots in discrete regions ...

  14. Modelling suction instabilities in soils at varying degrees of saturation

    Directory of Open Access Journals (Sweden)

    Buscarnera Giuseppe

    2016-01-01

    Full Text Available Wetting paths imparted by the natural environment and/or human activities affect the state of soils in the near-surface, promoting transitions across different regimes of saturation. This paper discusses a set of techniques aimed at quantifying the role of hydrologic processes on the hydro-mechanical stability of soil specimens subjected to saturation events. Emphasis is given to the mechanical conditions leading to coupled flow/deformation instabilities. For this purpose, energy balance arguments for three-phase systems are used to derive second-order work expressions applicable to various regimes of saturation. Controllability analyses are then performed to relate such work input with constitutive singularities that reflect the loss of strength under coupled and/or uncoupled hydro-mechanical forcing. A suction-dependent plastic model is finally used to track the evolution of stability conditions in samples subjected to wetting, thus quantifying the growth of the potential for coupled failure modes upon increasing degree of saturation. These findings are eventually linked with the properties of the field equations that govern pore pressure transients, thus disclosing a conceptual link between the onset of coupled hydro-mechanical failures and the evolution of suction with time. Such results point out that mathematical instabilities caused by a non-linear suction dependent behaviour play an important role in the advanced constitutive and/or numerical tools that are commonly used for the analysis of geomechanical problems in the unsaturated zone, and further stress that the relation between suction transients and soil deformations is a key factor for the interpretation of runaway failures caused by intense saturation events.

  15. 21 CFR 878.5040 - Suction lipoplasty system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Suction lipoplasty system. 878.5040 Section 878.5040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) Classification. Class II (special controls). Consensus standards and labeling restrictions. [63 FR 7705, Feb. 17...

  16. External suction versus water seal after selective pulmonary resection for lung neoplasm: a systematic review.

    Directory of Open Access Journals (Sweden)

    Tong Qiu

    Full Text Available OBJECTIVE: To evaluate whether external suction is more advantageous than water seal in patients undergoing selective pulmonary resection (SPR for lung neoplasm. SUMMARY OF BACKGROUND DATA: Whether external suction should be routinely applied in postoperative chest drainage is still unclear, particularly for lung neoplasm patients. To most surgeons, the decision is based on their clinical experience. METHODS: Randomized control trials were selected. The participants were patients undergoing SPR with lung neoplasm. Lung volume reduction surgery and pneumothorax were excluded. Suction versus non-suction for the intervention. The primary outcome was the incidence of persistent air leak (PAL. The definition of PAL was air leak for more than 3-7 days. The secondary outcomes included air leak duration, time of drainage, postoperative hospital stay and the incidence of postoperative pneumothorax. Studies were identified from literature collections through screening. Bias was analyzed and meta-analysis was used. RESULTS: From the 1824 potentially relevant trials, 6 randomized control trials involving 676 patients were included. There was no difference between external suction and water seal in decreasing the incidence of PAL [95% confidence interval (CI 0.81-2.16; z = 1.10; P = 0.27]. Regarding secondary outcomes, there were no differences in time of drainage (95% CI-0.36-1.56, P = 0.22, postoperative hospital stay (95% CI -.31-.54, P = 0.87 or incidence of postoperative pneumothorax (95% CI 0.18-.02, P = 0.05 between external suction and water seal. CONCLUSIONS: For participants, no differences are identified in terms of PAL incidence, drainage time, length of postoperative hospital stay or incidence of postoperative pneumothorax between external suction and water seal. The bias analysis should be emphasized. To the limitations of the bias and methodological differences among the included studies, we have no recommendation on

  17. Counter-rotating type axial flow pump unit in turbine mode for micro grid system

    International Nuclear Information System (INIS)

    Kasahara, R; Takano, G; Komaki, K; Murakami, T; Kanemoto, T

    2012-01-01

    Traditional type pumped storage system contributes to adjust the electric power unbalance between day and night, in general. This serial research proposes the hybrid power system combined the wind power unit with the pump-turbine unit, to provide the constant output for the grid system, even at the suddenly fluctuating/turbulent wind. In the pumping mode, the pump should operate unsteadily at not only the normal but also the partial discharge. The operation may be unstable in the rising portion of the head characteristics at the lower discharge, and/or bring the cavitation at the low suction head. To simultaneously overcome both weak points, the authors have proposed a superior pump unit that is composed of counter-rotating type impellers and a peculiar motor with double rotational armatures. This paper discusses the operation at the turbine mode of the above unit. It is concluded with the numerical simulations that this type unit can be also operated acceptably at the turbine mode, because the unit works so as to coincide the angular momentum change through the front runners/impellers with that thorough the rear runners/impellers, namely to take the axial flow at not only the inlet but also the outlet without the guide vanes.

  18. Investigation of the Flow Field and Performances of a Centrifugal Pump at Part Load

    Science.gov (United States)

    Prunières, R.; Inoue, Y.; Nagahara, T.

    2016-11-01

    Centrifugal pump performance curve instability, characterized by a local dent at part load, can be the consequence of flow instabilities in rotating or stationary parts. Such flow instabilities often result in abnormal operating conditions which can damage both the pump and the system. In order for the pump to have reliable operation over a wide flow rate range, it is necessary to achieve a design free of instability. The present paper focuses on performance curve instability of a centrifugal pump of mid specific speed (ωs = 0.65) for which instability was observed at part load during tests. The geometry used for this research consist of the first stage of a multi-stage centrifugal pump and is composed of a suction bend, a closed-type impeller, a vaned diffuser and return guide vanes. In order to analyse the instability phenomenon, PIV and CFD analysis were performed. Both methods qualitatively agree relatively well. It appears that the main difference before and after head drop is an increase of reverse flow rate at the diffuser passage inlet on the hub side. This reverse flow decreases the flow passing area at the diffuser passage inlet, disallowing effective flow deceleration and impairing static pressure recovery.

  19. Assessment of Feasibility of Suction Pile/Anchor Installation and Pullout Testing through Field Tests

    Directory of Open Access Journals (Sweden)

    R. Vijaya

    2014-09-01

    Full Text Available Suction pile anchors are large cylindrical (inverted bucket type structure open at the bottom and closed at the top and largely used for mooring of offshore platforms, exploratory vessels etc. Prediction of the mooring capacity of suction piles is a critical issue faced by the design engineers and rational methods are required to produce reliable designs. Tests have been conducted in an existing natural pond within NIOT campus with the objective of developing methodology of deployment, design and logistics for suction pile installation and testing of mooring capacity under static pullout. Small size suction piles with varying diameters and lengths have been used in the tests. The tests have been carried out in the natural pond with constant water depth of 1.5 m with the top 1.5 m layer of bed comprising soft marine clay. It is found that pile geometry, aspect ratio and angle of pullout have a significant influence on the response to pullout. As angle of mooring load application changes from vertical to horizontal the reaction offered by the suction pile changes from skin friction to passive soil resistance. Resistance offered by the internal plug of soil is found to vary according to dimension of the anchor piles.

  20. Analysis of vorticity dynamics for hump characteristics of a pump turbine model

    Energy Technology Data Exchange (ETDEWEB)

    Li, Deyou; Gong, Ruzhi; Wang, Hongjie; Han, Lei; Wei, Xianzhu; Qin, Daqing [School of Energy Science and Engineering, Harbin Institute of Technology, Harbin (China)

    2016-08-15

    Conventional parameters based on CFD methodology for the investigation on hump characteristics of a pump turbine cannot reflect the dynamic interaction mechanism between the runner and the fluid. This research presents a dynamic interaction mechanism of a pump turbine operating in the hump region. First, vorticity dynamic parameters were obtained based on the theory of vorticity dynamics. Second, 3-D unsteady flow simulations were performed in a full pump turbine model using the SST k-ω turbulence model, and numerical results have a good agreement with the experiments. Then, analysis was carried out to determine the relation between the vorticity dynamic parameters and hump characteristics. The results indicate that the theory of vorticity dynamics has an advantage in evaluating the dynamic performance of a pump turbine. The energy transfer between the runner and the fluid is through vorticity dynamic parameters-pressure and friction terms, in which the pressure term accounts for the most. Furthermore, vortex generation mainly results from the skin friction. Combining vorticity dynamic analysis with the method of Q-criterion indicates that hump characteristics are related to the reduction of the surface normal pressure work and vortex motion on the suction surfaces close to the leading edges in the runner, and the increase of skin friction work in the stay-guide vanes.

  1. Cannula Tip With Integrated Volume Sensor for Rotary Blood Pump Control: Early-Stage Development.

    Science.gov (United States)

    Cysyk, Joshua; Newswanger, Ray; Popjes, Eric; Pae, Walter; Jhun, Choon-Sik; Izer, Jenelle; Weiss, William; Rosenberg, Gerson

    2018-05-10

    The lack of direct measurement of left ventricular unloading is a significant impediment to the development of an automatic speed control system for continuous-flow left ventricular assist devices (cf-LVADs). We have developed an inlet cannula tip for cf-LVADs with integrated electrodes for volume sensing based on conductance. Four platinum-iridium ring electrodes were installed into grooves on a cannula body constructed from polyetheretherketone (PEEK). A sinusoidal current excitation waveform (250 μA pk-pk, 50 kHz) was applied across one pair of electrodes, and the conductance-dependent voltage was sensed across the second pair of electrodes. The conductance catheter was tested in an acute ovine model (n = 3) in conjunction with the HeartMate II rotary blood pump to provide circulatory support and unload the ventricle. Echocardiography was used to measure ventricular size during pump support for verification for the conductance measurements. The conductance measurements correlated linearly with the echocardiography dimension measurements more than the full range of pump support from minimum support to suction. This cannula tip will enable the development of automatic control systems to optimize pump support based on a real-time measurement of ventricular size.

  2. Numerical investigations on cavitating flows with thermodynamic effects in a diffuser-type centrifugal pump

    International Nuclear Information System (INIS)

    Xuelin, Tang Xue; Liyuan, Bian; Fujun, Wang; Xiaoqin, Lin; Man, Hao

    2013-01-01

    A cavitation model with thermodynamic effects for cavitating flows in a diffuser-type centrifugal pump is developed based on the bubble two-phase flow model. The proposed cavitation model includes mass, momentum, and energy transportations according to the thermodynamic mechanism of cavitation. Numerical simulations are conducted inside the entire passage of the centrifugal pump by using the proposed cavitation model and the renormalization group-based k - ε turbulent model coupled with the energy transportation equation. By using the commercial computational fluid dynamics software FLUENT 6.3, we have shown that the predicted performance characteristics of the pump, as well as the pressure, vapor, and density distributions in the impeller, agree well with that calculated by the full cavitation model. Simulation results show that cavitation initially occurs slightly behind the inlet of the blade suction surface, i.e., the area with maximum vapor concentration and minimum pressure. The predicted temperature field shows that the reduction in temperature restrains the growth of cavitating bubbles. Therefore, the thermodynamic effect should be treated as a necessary factor in cavitation models. Comparison results validate the efficiency and accuracy of the numerical technique in simulating cavitation flows in centrifugal pumps.

  3. Half versus full vacuum suction drainage after modified radical mastectomy for breast cancer- a prospective randomized clinical trial[ISRCTN24484328

    Directory of Open Access Journals (Sweden)

    Singh JP

    2005-01-01

    Full Text Available Abstract Background Suction drains are routinely used after modified radical mastectomy and are an important factor contributing to increased hospital stay as the patients are often discharged only after their removal. Amongst various factors that influence the amount of postoperative drainage, the negative suction pressure applied to the drain has been reported to be of great significance. While a high negative suction pressure is expected to drain the collection and reduce the dead space promptly, it may also prevent the leaking lymphatics from closing and lead to increased drainage from the wound. Against this background a prospective randomized clinical study was conducted to compare the amount and duration of drainage between a half negative suction and full vacuum suction drainage in patients following modified radical mastectomy. The associated postoperative morbidity was also compared between the two groups. Methods 85 FNAC (fine needle aspiration cytology proven cases of locally advanced breast cancer were randomized. (Using randomly ordered sealed envelops, which were opened immediately before the closure of the wound in to 50 patients with full vacuum suction (pressure = 700 g/m2 and 35 cases in to half vacuum suction drainage (pressure = 350 g/m2 groups. The two groups were comparable in respect of age, weight, and technique of operation and extent of axillary dissection. Surgery was performed by the same surgical team comprising of five surgeons (two senior and three resident surgeons using a standardized technique with electrocautery. External compression dressing was provided over the axilla for first 48 hrs and following that patients were encouraged to do active and passive shoulder exercises. The outcomes measured were postoperative morbidity and the length of hospital stay. Statistical methods used: Descriptive studies were performed with SPSS version 10 and group characteristics were compared using student t-test. Results

  4. Effects of suction-dredging for cockles on non-target fauna in the Wadden Sea

    NARCIS (Netherlands)

    Hiddink, JG

    2003-01-01

    Suction dredging for cockles removes large cockles from tidal flats and may also cause mortality of non-target fauna and make the habitat less suitable for some species. This study examines whether suction dredging for cockles on tidal flats of the Dutch Wadden Sea had affected densities of

  5. Australian fur seals (Arctocephalus pusillus doriferus use raptorial biting and suction feeding when targeting prey in different foraging scenarios.

    Directory of Open Access Journals (Sweden)

    David P Hocking

    Full Text Available Foraging behaviours used by two female Australian fur seals (Arctocephalus pusillus doriferus were documented during controlled feeding trials. During these trials the seals were presented with prey either free-floating in open water or concealed within a mobile ball or a static box feeding device. When targeting free-floating prey both subjects primarily used raptorial biting in combination with suction, which was used to draw prey to within range of the teeth. When targeting prey concealed within either the mobile or static feeding device, the seals were able to use suction to draw out prey items that could not be reached by biting. Suction was followed by lateral water expulsion, where water drawn into the mouth along with the prey item was purged via the sides of the mouth. Vibrissae were used to explore the surface of the feeding devices, especially when locating the openings in which the prey items had been hidden. The mobile ball device was also manipulated by pushing it with the muzzle to knock out concealed prey, which was not possible when using the static feeding device. To knock prey out of this static device one seal used targeted bubble blowing, where a focused stream of bubbles was blown out of the nose into the openings in the device. Once captured in the jaws, prey items were manipulated and re-oriented using further mouth movements or chews so that they could be swallowed head first. While most items were swallowed whole underwater, some were instead taken to the surface and held in the teeth, while being vigorously shaken to break them into smaller pieces before swallowing. The behavioural flexibility displayed by Australian fur seals likely assists in capturing and consuming the extremely wide range of prey types that are targeted in the wild, during both benthic and epipelagic foraging.

  6. Primary Total Knee Replacement: Is Suction a Portal of Infection?

    Science.gov (United States)

    Budnar, Vijaya M; Amirfeyz, Rouin; Ng, Michael; Bannister, Gordon C; Blom, Ashley W

    2009-01-01

    INTRODUCTION Pulsed lavage during a total knee replacement usually leaves a pool of fluid on the surgical drapes. It is common practice to suck away this fluid using the same suction device used intra-operatively. This could be a cause of direct wound contamination. We hypothesised that bacteria contaminate fluid that collects around the foot in total knee replacement surgery and that suction equipment could be a portal of contamination. We also hypothesised that bacterial count in the fluid is lower if chlorhexidine, rather than saline, is used in the pulsed lavage. PATIENTS AND METHODS Forty patients undergoing primary total knee replacement were divided into two groups. The first group had pulsed lavage with normal saline and the second with 0.05% chlorhexidine. RESULTS At the end of the operation, 20 ml of fluid, pooled on the surgical drapes was aspirated and cultured for bacterial growth. None of the fluid samples showed bacterial growth. CONCLUSIONS Suction device used peri-operatively during knee replacement is unlikely to be a cause of wound contamination. Pulsed lavage with normal saline is as effective as lavage with chlorhexidine. PMID:19335972

  7. Output characteristics of a series three-port axial piston pump

    Science.gov (United States)

    Zhang, Xiaogang; Quan, Long; Yang, Yang; Wang, Chengbin; Yao, Liwei

    2012-05-01

    Driving a hydraulic cylinder directly by a closed-loop hydraulic pump is currently a key research area in the field of electro-hydraulic control technology, and it is the most direct means to improve the energy efficiency of an electro-hydraulic control system. So far, this technology has been well applied to the pump-controlled symmetric hydraulic cylinder. However, for the differential cylinder that is widely used in hydraulic technology, satisfactory results have not yet been achieved, due to the asymmetric flow constraint. Therefore, based on the principle of the asymmetric valve controlled asymmetric cylinder in valve controlled cylinder technology, an innovative idea for an asymmetric pump controlled asymmetric cylinder is put forward to address this problem. The scheme proposes to transform the oil suction window of the existing axial piston pump into two series windows. When in use, one window is connected to the rod chamber of the hydraulic cylinder and the other is linked with a low-pressure oil tank. This allows the differential cylinders to be directly controlled by changing the displacement or rotation speed of the pumps. Compared with the loop principle of offsetting the area difference of the differential cylinder through hydraulic valve using existing technology, this method may simplify the circuits and increase the energy efficiency of the system. With the software SimulationX, a hydraulic pump simulation model is set up, which examines the movement characteristics of an individual piston and the compressibility of oil, as well as the flow distribution area as it changes with the rotation angle. The pump structure parameters, especially the size of the unloading groove of the valve plate, are determined through digital simulation. All of the components of the series arranged three distribution-window axial piston pump are designed, based on the simulation analysis of the flow pulse characteristics of the pump, and then the prototype pump is made

  8. Present knowledge about Laboratory Testing of Axial Loading on Suction Caissons

    DEFF Research Database (Denmark)

    Manzotti, E.; Vaitkunaite, Evelina; Ibsen, Lars Bo

    Offshore wind turbines are increasing in both efficiency and size. More economical foundations for such light structures are under investigation, and suction caisson was shown to be particularly suitable for this purpose. In multi-pod foundation configuration, the overturning moment given by loads...... on the structure is resisted by push-pull loads on the vertical axis of each suction caisson. Relevant works where this situation is examined by means of laboratory testing are summarized in this article, then different conclusions are followed by discussion and comparison. In the initial theoretical section...

  9. Operation characteristic of a heat pump of mechanical vapor recompression propelled by fans and its performance analysis applied to waste-water treatment

    Science.gov (United States)

    Weike, Pang; Wenju, Lin; Qilin, Pan; Wenye, Lin; Qunte, Dai; Luwei, Yang; Zhentao, Zhang

    2014-01-01

    In this paper, a set of heat pump (called as Mechanical Vapor Recompression, MVR) propelled by a centrifugal fan is tested and it shows some special characteristic when it works together with a falling film evaporator. Firstly, an analysis of the fan's suction and discharge parameters at stable state, such as its pressure and temperature, indicates that a phenomenon of wet compression is probably to appear during vapor compression. As a result, superheat after saturated vapor is compressed is eliminated, which reduces discharge temperature of the system. It is because drops boil away and absorb the super heat into their latent heat during vapor compression. Meanwhile, drops in the suction vapor add to the compressed vapor, which increase the given heat of the MVR heat pump. Next, assistant electric heat could adjust and keep steady of the operating pressure and temperature of an MVR heat pump. With the evaporation temperature up to be high, heat balance is broken and supplement heat needs to increase. Thirdly, the performance of an MVR heat pump is affect by the balance of falling film and evaporation that has an effect on heat transfer. Then, two parameters standing for the performance are measured as it runs in practical condition. The two important parameters are consumptive electricity power and productive water capacity. According to theoretical work in ideal condition by calculation and fan's input power by measure as running, adiabatic efficiency (ηad) of a centrifugal fan is calculated when it is applied in a heat pump of MVR. Following, based on ηad, practical SMER and COP of an MVR heat pump are discovered to be correlative with it. Finally, in dependence on productive water in theory and in practice, displacement efficiency (ηv) of centrifugal fans is obtained when compressing vapor, and so provide some references of matching a fan for an MVR heat pump. On the other hand, it is helpful to research and develop MVR heat pumps, and also to check

  10. Effects of vacuum suctioning and strategic drape tenting on oxygen concentration in a simulated surgical field.

    Science.gov (United States)

    Kung, Theodore A; Kong, Sarah W; Aliu, Oluseyi; Azizi, Jahan; Kai, Salim; Cederna, Paul S

    2016-02-01

    To investigate the isolated and combined effects of vacuum suctioning and strategic drape tenting on oxygen concentration in an experimental setting. Experimental. Clinical simulation center of a university-affiliated hospital. Mannequin simulation of a patient undergoing facial surgery under sedation anesthesia. Supplemental oxygen was delivered via nasal cannula. Vacuum suctioning and strategic drape tenting. The experimental trials entailed measuring oxygen concentration around the nasal cannula continuously either in the presence or absence of a standard operating room vacuum suction system and strategic tenting of surgical drapes. The primary outcome was the time required for oxygen concentration to reach 21%. In the control group (without suction or strategic tenting), a mean time of 180 seconds elapsed until the measured oxygen concentration reached 21% after cessation of oxygen delivery. Use of a vacuum suction device alone (110 seconds; P strategic tenting (110 seconds; P strategic tenting of surgical drapes has a theoretical benefit to decreasing the pooling of oxygen around the surgical site, further investigation is necessary before its routine use is recommended. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. A new suction mask to reduce leak during neonatal resuscitation: a manikin study.

    Science.gov (United States)

    Lorenz, Laila; Maxfield, Dominic A; Dawson, Jennifer A; Kamlin, C Omar F; McGrory, Lorraine; Thio, Marta; Donath, Susan M; Davis, Peter G

    2016-09-01

    Leak around the face mask is a common problem during neonatal resuscitation. A newly designed face mask using a suction system to enhance contact between the mask and the infant's face might reduce leak and improve neonatal resuscitation. The aim of the study is to determine whether leak is reduced using the suction mask (Resusi-sure mask) compared with a conventional mask (Laerdal Silicone mask) in a manikin model. Sixty participants from different professional categories (neonatal consultants, fellows, registrars, nurses, midwives and students) used each face mask in a random order to deliver 2 min of positive pressure ventilation to a manikin. Delivered airway pressures were measured using a pressure line. Inspiratory and expiratory flows were measured using a flow sensor, and expiratory tidal volumes and mask leaks were derived from these values. A median (IQR) leak of 12.1 (0.6-39.0)% was found with the conventional mask compared with 0.7 (0.2-4.6)% using the suction mask (p=0.002). 50% of the participants preferred to use the suction mask and 38% preferred to use the conventional mask. There was no correlation between leak and operator experience. A new neonatal face mask based on the suction system reduced leak in a manikin model. Clinical studies to test the safety and effectiveness of this mask are needed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  12. Development of Energy Efficiency Design Map based on acoustic resonance frequency of suction muffler in compressor

    International Nuclear Information System (INIS)

    Oh, Seungjae; Wang, Semyung; Cho, Sungman

    2015-01-01

    Highlights: • Development of Energy Efficiency Design Map. • Experimental validation of Energy Efficiency Design Map. • Suggestion regarding the Acoustically Supercharged Energy Efficiency. • Sensitivity analysis of the Energy Efficiency Ratio with respect to acoustic pressure. • Suggestion regarding the hybrid coupling method for acoustic analysis in compressor. - Abstract: The volumetric efficiency of the Internal Combustion (IC) engine and compressor can be increased by properly adjusting the acoustic resonance frequency of the suction muffler or the suction valve timing without any additional equipment or power source. This effect is known as acoustic supercharging. However, the energy efficiency has become more important than the volumetric efficiency because of the energy shortage issue and factors influencing consumers’ purchasing decisions. Therefore, methods for increasing the energy efficiency using the acoustic effect in the suction part of IC engine and compressor should be considered. In this study, a systematic method for improving the energy efficiency using the acoustic effect in the suction part of the compressor used in refrigerators and air conditioners was developed for the first time. This effect is named as the Acoustically Supercharged Energy Efficiency (ASEE). For the ASEE, first, a hybrid coupling method was suggested for the acoustical analysis in the suction part of the compressor. Next, an Energy Efficiency Design Map (EEDM) was proposed. This can serve as a design guide for suction mufflers in terms of the energy efficiency. Finally, sensitivity analyses of the Energy Efficiency Ratio (EER) and total massflow rate with respect to the acoustic pressure were conducted to identify the relationship between the acoustic pressure and the suction valve motion. This provides the physical background for the EEDM

  13. 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.

  14. Application of Adaptive Starling-Like Controller to Total Artificial Heart Using Dual Rotary Blood Pumps.

    Science.gov (United States)

    Ng, Boon C; Smith, Peter A; Nestler, Frank; Timms, Daniel; Cohn, William E; Lim, Einly

    2017-03-01

    The successful clinical applicability of rotary left ventricular assist devices (LVADs) has led to research interest in devising a total artificial heart (TAH) using two rotary blood pumps (RBPs). The major challenge when using two separately controlled LVADs for TAH support is the difficulty in maintaining the balance between pulmonary and systemic blood flows. In this study, a starling-like controller (SLC) hybridized with an adaptive mechanism was developed for a dual rotary LVAD TAH. The incorporation of the adaptive mechanism was intended not only to minimize the risk of pulmonary congestion and atrial suction but also to match cardiac demand. A comparative assessment was performed between the proposed adaptive starling-like controller (A-SLC) and a conventional SLC as well as a constant speed controller. The performance of all controllers was evaluated by subjecting them to three simulated scenarios [rest, exercise, head up tilt (HUT)] using a mock circulation loop. The overall results showed that A-SLC was superior in matching pump flow to cardiac demand without causing hemodynamic instabilities. In contrast, improper flow regulation by the SLC resulted in pulmonary congestion during exercise. From resting supine to HUT, overpumping of the RBPs at fixed speed (FS) caused atrial suction, whereas implementation of SLC resulted in insufficient flow. The comparative study signified the potential of the proposed A-SLC for future TAH implementation particularly among outpatients, who are susceptible to variety of clinical scenarios.

  15. COMPARISON OF THE EFFECTIVENESS OF TWO LEVELS OF SUCTION PRESSURE ON OXYGEN SATURATION IN PATIENTS WITH ENDOTRACHEAL TUBE

    Directory of Open Access Journals (Sweden)

    Muhaji

    2017-12-01

    Full Text Available Background: Endotracheal suctioning is one of the common supportive measures in intensive care units (ICU, which may be related to complications such as hypoxia. However, a questionable efficacy is still identified to choose suctioning pressure between 130 mmHg and 140 mmHg that is effective for patients with endotracheal tube. Objective: To compare the effectiveness of 130 mmHg and 140 mmHg suctioning pressure on oxygen saturation in patients with endotracheal tube. Methods: This research used a quasy experimental design with pretest and posttest group. The study was conducted from 31 January to 1 March 2017 in the Hospital of Panti Wilasa Citarum and Hospital of Roemani Muhammadiyah Semarang. There were 30 samples recruited using consecutive sampling, with 15 assigned in the 130 mmHg and 140 mmHg suctioning pressure group. Pulse oximetry was used to measure oxygen saturation. Paired t-test and Independent t-test were used for data analysis. Results: Findings showed that there was a statistically significant effect of 130 and 140 mmHg suctioning pressure on oxygen saturation in patients with ETT with p-value <0.05. There was a significant mean difference of oxygen saturation between 130 mmHg and 140 mmHg suctioning pressure group with p-value 0.004 (<0.05. The mean difference of oxygen saturation between both groups was 13.157. Conclusion: The 140 mmHg suctioning pressure is more effective compared with 130 mmHg suctioning pressure in increasing oxygen saturation in patients with ETT.

  16. Unsteady numerical simulation for gas–liquid two-phase flow in self-priming process of centrifugal pump

    International Nuclear Information System (INIS)

    Huang, Si; Su, Xianghui; Guo, Jing; Yue, Le

    2014-01-01

    Highlights: • The transient gas–liquid two-phase flow fields in the self-priming centrifugal pump are simulated. • The self-priming time and performance are estimated. • The air void fraction and two phase distribution are obtained.· The hole on the volute plays a significant role for gas exhausting. • The frequency of the impulsive pressure basically conforms to that of the air exhausted out of the pump. - Abstract: Self-priming pumps start up without pre-irrigation, and then work as common pumps when air in the pump is exhausted. The transient gas–liquid flow at the start-up stage inside a self-priming pump is an interesting process which greatly influences performance of the pump. In this paper, a conventional vertical self-priming centrifugal pump was selected as the object. Using unsteady numerical simulation, the authors investigated the transient gas–liquid two-phase flow in the self-priming centrifugal pump during the self-priming process. The main innovation in the simulation was that a section of the suction pipe filled with air was set as the initial condition, which conformed to the actual self-priming conditions. The gas–liquid two-phase distribution, the pressure and velocity in relation to time were computed and analyzed. Flow rates of both phases with time at the pump inlet and outlet were obtained based on the simulation, which could be used to estimate the self-priming time and other performance parameters. Finally, the numerical method and results for gas–liquid two-phase flow in the self-priming pump was partly validated by the pump performance test

  17. External Suction and Fluid Output in Chest Drains After Lobectomy

    DEFF Research Database (Denmark)

    Lijkendijk, Marike; Neckelmann, Kirsten; Licht, Peter B

    2018-01-01

    influences the amount of fluid. METHODS: We randomly assigned (1:1) 106 patients who underwent lobectomy to either low (-5 cm H2O) or high (-20 cm H2O) external suction using an electronic chest drainage system. Only one chest drain was allowed, and we used strict algorithms for chest drain removal, which...... was delegated to staff nurses: air leakage less than 20 mL/min for 6 hours regardless of fluid output, provided it was serous. The primary end point was fluid output after 24 and 48 hours. RESULTS: Mean fluid output was significantly higher with high suction after both 24 (338 ± 265 mL versus 523 ± 215 m...

  18. Industrial aspects of cavitation in pumps

    Energy Technology Data Exchange (ETDEWEB)

    Canavelis, R; Grison, P

    1986-01-01

    Increasing the unit power of hydraulic turbomachines, as well as reducing their size, lead one to operate them on the verge of cavitation. It is then no more possible to think only of modifications in the machine performance, as many other phenomena take place long before this deterioration appears: noise, presence of bubbles, erosion, pressure fluctuations, etc. The article surveys the various phenomena encountered in pumps for various levels of suction pressure. Each is briefly described, with its implication on the machine. Industrial examples illustrate these phenomena and bring to light their importance. Lastly, the research tools used to study them and to overcome the present limitations are reviewed. Emphasis is made in particular on the possibility of predicting cavitation pockets either from numerical models of the flow or from experiments on actual models. Studies on erosion are also listed: mechanism, main parameters, measuring means, similitude laws for turbomachines.

  19. Savannah River Site reactor hardware design modification study

    International Nuclear Information System (INIS)

    Fisher, J.E.

    1990-03-01

    A study was undertaken to assess the merits of proposed design modifications to the SRS reactors. The evaluation was based on the responses calculated by the RELAP5 systems code to double-ended guillotine break loss-of-coolant-accidents (DEGB LOCAs). The three concepts evaluated were (a) elevated plenum inlet piping with a guard vessel and clamshell enclosures, (b) closure of both rotovalves in the affected loop, and (c) closure of the pump suction valve in the affected loop. Each concept included a fast reactor shutdown (to 65% power in 100 ms) and a 2-s ac pump trip. For the elevated piping design, system recovery was predicted for breaks in the plenum inlet or pump suction piping; response to the pump discharge break location did not show improvement compared to the present system configuration. The rotovalve closure design improved system response to plenum inlet or pump discharge breaks; recovery was not predicted for pump suction breaks. The pump suction valve closure design demonstrated system recovery for all break locations downstream of the valve. A combination of features is recommended to ensure liquid inventory recovery for all break locations. The elevated piping design performance during pump discharge breaks would be improved with addition of a dc pump trip in the affected loop. Valve closure design performance for a break location in the short section of piping between the reactor concrete shield and the pump suction valve would benefit from the clamshell enclosing that section of piping. 12 refs., 10 figs., 2 tabs

  20. Response of skirted suction caissons to monotonic lateral loading in saturated medium sand

    Science.gov (United States)

    Li, Da-yong; Zhang, Yu-kun; Feng, Ling-yun; Guo, Yan-xue

    2014-08-01

    Monotonic lateral load model tests were carried out on steel skirted suction caissons embedded in the saturated medium sand to study the bearing capacity. A three-dimensional continuum finite element model was developed with Z_SOIL software. The numerical model was calibrated against experimental results. Soil deformation and earth pressures on skirted caissons were investigated by using the finite element model to extend the model tests. It shows that the "skirted" structure can significantly increase the lateral capacity and limit the deflection, especially suitable for offshore wind turbines, compared with regular suction caissons without the "skirted" at the same load level. In addition, appropriate determination of rotation centers plays a crucial role in calculating the lateral capacity by using the analytical method. It was also found that the rotation center is related to dimensions of skirted suction caissons and loading process, i.e. the rotation center moves upwards with the increase of the "skirted" width and length; moreover, the rotation center moves downwards with the increase of loading and keeps constant when all the sand along the caisson's wall yields. It is so complex that we cannot simply determine its position like the regular suction caisson commonly with a specified position to the length ratio of the caisson.

  1. Energy Performance and Pressure Fluctuation of a Multiphase Pump with Different Gas Volume Fractions

    Directory of Open Access Journals (Sweden)

    Jinsong Zhang

    2018-05-01

    Full Text Available Large petroleum resources in deep sea, and huge market demands for petroleum need advanced petroleum extraction technology. The multiphase pump, which can simultaneously transport oil and gas with considerable efficiency, has been a crucial technology in petroleum extraction. A numerical approach with mesh generation and a Navier-Stokes equation solution is employed to evaluate the effects of gas volume fraction on energy performance and pressure fluctuations of a multiphase pump. Good agreement of experimental and calculation results indicates that the numerical approach can accurately simulate the multiphase flow in pumps. The pressure rise of a pump decreases with the increasing of flow rate, and the pump efficiency decreases with the increasing of GVF (the ratio of the gas volume to the whole volume. Results show that the dominant frequencies of pressure fluctuation in the impeller and diffuser are eleven and three times those of the impeller rotational frequency, respectively. Due to the larger density of water and centrifugal forces, the water aggregates to the shroud and the gas gathers to the hub, which renders the distribution of GVF in the pump uneven. A vortex develops at the blade suction side, near the leading edge, induced by the leakage flow, and further affects the pressure fluctuation in the impeller. The obvious vortex in the diffuser indicates that the design of the divergence angle of the diffuser is not optimal, which induces flow separation due to large diffusion ratio. A uniform flow pattern in the impeller indicates good hydraulic performance of the pump.

  2. Supermarket refrigeration. Optimization of suction pressure in existing refrigerators; Supermarktkaelte. Saugdruck optimieren in Bestandskaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Philipp; Mueller, Markus [Eckelmann AG, Wiesbaden (Germany)

    2012-06-15

    The new E*LDS firmware E*COP{sup +} from Eckelmann AG (Wiesbaden, Federal Republic of Germany) for the optimization of the suction pressure supplies a demand-oriented adaptation of the suction pressure. The new feature is ideal for an update of existing systems with thermostatic expansion valves. Using this update operators of supermarket operators may save about 10% energy with little effort.

  3. Natural convection boundary layer with suction and mass transfer in a porous medium

    International Nuclear Information System (INIS)

    Bestman, A.R.

    1989-03-01

    The free convection boundary layer flow with simultaneous heat and mass transfer in a porous medium is studied when the boundary wall moves in its own plane with suction. The study also incorporates chemical reaction for the very simple model of a binary reaction with Arrhenius activation energy. For large suction asymptotic approximate solutions are obtained for the flow variables for various values of the activation energy. (author). 10 refs, 2 figs

  4. Miscellaneous component design for Tank 241SY101 pump removal

    International Nuclear Information System (INIS)

    Huang, F.H.

    1995-01-01

    A mixer pump has been used to mitigate the hydrogen build-up in tank 241SY101 (SY101), located in the 200 West Area of the Hanford Site. New equipment is being prepared for the removal, transport, storage, and disposal of the test pump. The disposal equipment for the test pump now in tank SY101 includes a shipping container, a strong back, a lifting beam, a test weight, container support stands, a modified mock-up pump, a flexible receiver blast shield, a lifting yoke, and a yoke brace. The structural evaluations of container and strong back are detailed in another supporting document (WHC 1994a), the engineering analyses of flexible receiver blast shield/lifting yoke and yoke brace are given in other supporting documents (WHC 1994b, WHC 1994c), respectively. Engineering tasks that were contracted to Advanced Engineering Consultants (AEC) include the design and analysis of the following. Two spreader-beam lifting devices. a Container test weight. Container support saddles. Mock-up pump modification. This report documents the work description, design basis, assumptions, and design calculations provided by AEC for the above components. All AEC documents appear in Appendix A. Additional work conducted by Westinghouse Hanford Company (WHC) on the modified container test weight, modification to the mock-up pump, the removable support for the transport assembly, and saddle modification for air pallets also are included in this document

  5. The effect of intraoral suction on oxygen-enriched surgical environments: a mechanism for reducing the risk of surgical fires.

    Science.gov (United States)

    VanCleave, Andrea M; Jones, James E; McGlothlin, James D; Saxen, Mark A; Sanders, Brian J; Vinson, LaQuia A

    2014-01-01

    In this study, a mechanical model was applied in order to replicate potential surgical fire conditions in an oxygen-enriched environment with and without high-volume suction typical for dental surgical applications. During 41 trials, 3 combustion events were measured: an audible pop, a visible flash of light, and full ignition. In at least 11 of 21 trials without suction, all 3 conditions were observed, sometimes with an extent of fire that required early termination of the experimental trial. By contrast, in 18 of 20 with-suction trials, ignition did not occur at all, and in the 2 cases where ignition did occur, the fire was qualitatively a much smaller, candle-like flame. Statistically comparing these 3 combustion events in the no-suction versus with-suction trials, ignition (P = .0005), audible pop (P = .0211), and flash (P = .0092) were all significantly more likely in the no-suction condition. These results suggest a possible significant and new element to be added to existing surgical fire safety protocols toward making surgical fires the "never-events" they should be.

  6. Endoscopic en bloc resection of an exophytic gastrointestinal stromal tumor with suction excavation technique

    Science.gov (United States)

    Choi, Hyuk Soon; Chun, Hoon Jai; Kim, Kyoung-Oh; Kim, Eun Sun; Keum, Bora; Jeen, Yoon-Tae; Lee, Hong Sik; Kim, Chang Duck

    2016-01-01

    Here, we report the first successful endoscopic resection of an exophytic gastrointestinal stromal tumor (GIST) using a novel perforation-free suction excavation technique. A 49-year-old woman presented for further management of a gastric subepithelial tumor on the lesser curvature of the lower body, originally detected via routine upper gastrointestinal endoscopy. Abdominal computed tomography and endoscopic ultrasound showed a 4-cm extraluminally protruding mass originating from the muscularis propria layer. The patient firmly refused surgical resection owing to potential cardiac problems, and informed consent was obtained for endoscopic removal. Careful dissection and suction of the tumor was repeated until successful extraction was achieved without serosal injury. We named this procedure the suction excavation technique. The tumor’s dimensions were 3.5 cm × 2.8 cm × 2.5 cm. The tumor was positive for C-KIT and CD34 by immunohistochemical staining. The mitotic count was 6/50 high-power fields. The patient was followed for 5 years without tumor recurrence. This case demonstrated the use of endoscopic resection of an exophytic GIST using the suction excavation technique as a potential therapy without surgical resection. PMID:27340363

  7. Theoretical Analysis of Effects of Wall Suction on Entropy Generation Rate in Laminar Condensate Layer on Horizontal Tube

    Directory of Open Access Journals (Sweden)

    Tong-Bou Chang

    2014-01-01

    Full Text Available The effects of wall suction on the entropy generation rate in a two-dimensional steady film condensation flow on a horizontal tube are investigated theoretically. In analyzing the liquid flow, the effects of both the gravitational force and the viscous force are taken into account. In addition, a film thickness reduction ratio, Sf, is introduced to evaluate the effect of wall suction on the thickness of the condensate layer. The analytical results show that, the entropy generation rate depends on the Jakob number Ja, the Rayleigh number Ra, the Brinkman number Br, the dimensionless temperature difference ψ, and the wall suction parameter Sw. In addition, it is shown that in the absence of wall suction, a closed-form correlation for the Nusselt number can be derived. Finally, it is shown that the dimensionless entropy generation due to heat transfer, NT, increases with an increasing suction parameter Sw, whereas the dimensionless entropy generation due to liquid film flow friction, NF, decreases.

  8. LES-based characterization of a suction and oscillatory blowing fluidic actuator

    Science.gov (United States)

    Kim, Jeonglae; Moin, Parviz

    2015-11-01

    Recently, a novel fluidic actuator using steady suction and oscillatory blowing was developed for control of turbulent flows. The suction and oscillatory blowing (SaOB) actuator combines steady suction and pulsed oscillatory blowing into a single device. The actuation is based upon a self-sustained mechanism of confined jets and does not require any moving parts. The control output is determined by a pressure source and the geometric details, and no additional input is needed. While its basic mechanisms have been investigated to some extent, detailed characteristics of internal turbulent flows are not well understood. In this study, internal flows of the SaOB actuator are simulated using large-eddy simulation (LES). Flow characteristics within the actuator are described in detail for a better understanding of the physical mechanisms and improving the actuator design. LES predicts the self-sustained oscillations of the turbulent jet. Switching frequency, maximum velocity at the actuator outlets, and wall pressure distribution are in good agreement with the experimental measurements. The computational results are used to develop simplified boundary conditions for numerical experiments of active flow control. Supported by the Boeing company.

  9. The application of suction caisson technology to offshore wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-09-15

    A mathematical model describing the behaviour of caisson foundations for offshore wind turbines has been developed. The model has been verified and calibrated through laboratory and field work. Simultaneously, conceptual designs of wind turbine foundations incorporating suction caissons were studied using the same model. It was concluded that much of the seabed around Britain is well suited to the use of caissons and monopod and quadropod structures are superior to tripods. Although suction caissons are vulnerable to scour, rock dumping can largely eliminate this potential problem. The next phase will be to install a fully instrumented full-scale prototype to monitor the effects of wind and waves. The main contractor was SLP Engineering Limited and about 75 per cent of the funding came from the DTI.

  10. Fluid Model of Sliding Suction Cup of Wall-climbing Robots

    Directory of Open Access Journals (Sweden)

    Fu Zhuang

    2008-11-01

    Full Text Available The adhering capability, one of the most important performance indexes of wall-climbing robots(WCRs, should be taken into account when a WCR is designed. This paper proposes a novel approach for investigating the adhering characteristics of the sliding suction cup (SSCs using fluid network theory to enhance the adhering capability of WCRs. The fluid models of the SSCs of two WCRs are developed and equivalent circuits in three cases are presented. The dynamic responses of negative pressure in SSCs are obtained and validated by a set of experiments. It indicated that the theoretical analysis is reasonable and can give some valuable design criteria on the structure parameters of SSCs and control strategies of suction force of SSCs.

  11. Reversible pumped hydro - benefits and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Torbjoern K.; Walseth, Eve C.

    2010-07-01

    process during start-up in turbine mode, which is undesirable when the goal is to increase the flexibility. The introduction of the free market and increased focus on non-regulative renewable energy sources has led to a need for new operating patterns in the Norwegian hydro power system. Reversible pump turbines can increase both the flexibility and stabilize the grid with increased production from non-regulative renewable energy sources. (Author)

  12. The effects of suction and pin/lock suspension systems on transtibial amputees' gait performance.

    Directory of Open Access Journals (Sweden)

    Hossein Gholizadeh

    Full Text Available BACKGROUND: The suction sockets that are commonly prescribed for transtibial amputees are believed to provide a better suspension than the pin/lock systems. Nevertheless, their effect on amputees' gait performance has not yet been fully investigated. The main intention of this study was to understand the potential effects of the Seal-in (suction and the Dermo (pin/lock suspension systems on amputees' gait performance. METHODOLOGY/PRINCIPAL FINDINGS: Ten unilateral transtibial amputees participated in this prospective study, and two prostheses were fabricated for each of them. A three-dimensional motion analysis system was used to evaluate the temporal-spatial, kinematics and kinetics variables during normal walking. We also asked the participants to complete some part of Prosthesis Evaluation Questionnaire (PEQ regarding their satisfaction and problems with both systems. The results revealed that there was more symmetry in temporal-spatial parameters between the prosthetic and sound limbs using the suction system. However, the difference between two systems was not significant (p<0.05. Evaluation of kinetic data and the subjects' feedback showed that the participants had more confidence using the suction socket and the sockets were more fit for walking. Nevertheless, the participants had more complaints with this system due to the difficulty in donning and doffing. CONCLUSION: It can be concluded that even though the suction socket could create better suspension, fit, and gait performance, overall satisfaction was higher with the pin/lock system due to easy donning and doffing of the prosthesis. TRIAL REGISTRATION: irct.ir IRCT2014012816395N1.

  13. Numerical Study of Piping Limits for Suction Installation of Offshore Skirted Foundations an Anchors in Layered Sand

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Thilsted, C. L.

    2010-01-01

    Skirted foundations and anchors have proved to be competitive solutions for various types of fixed offshore platforms, subsea systems and an attractive foundation alternative for offshore wind turbines. One main design challenge for skirted structures in sand is to penetrate the skirted deep enough...... to obtain the required capacity. In order to overcome the high penetration resistance in sand suction assisted penetration is needed. Suction installation may cause the formation of piping channels, which break down the hydraulic seal and prevent further installation. This paper presents a numerical study...... of failure limits during suction installation in respect to both homogenous and layered soil profile. A numerical flow analysis is performed to determine the hydraulic gradients developing in response to the suction applied, and the results are presented as simple closed form solutions useful for evaluation...

  14. Dome shaped micro-laser encapsulated in a flexible film

    Science.gov (United States)

    Ioppolo, T.; Manzo, M.

    2014-11-01

    In this paper, we demonstrated multimode laser emission from a dome shaped micro-scale resonator encapsulated in a flexible polymer film. The resonator with a radius of ~60 microns was made of Norland Blocking Adhesive (NBA 107) doped with a solution of rhodamine 6G and ethanol. The dome was encapsulated in a flexible polymeric film made of polydymethylsiloxane (PDMS) with a thickness of 1 mm. The micro-scale laser was optically pumped using a frequency doubled Q-switch Nd:YAG laser with pulse repetition of 10 Hz and pulse duration of 9 ns. Experiments were carried out to investigate the lasing properties of this laser structure. The pumping threshold for multimode laser emission was below 100 µJ cm-2. The average optical quality factor for all observed laser modes was of the order of 104. Using a fluence of 315.8 µJ cm-2 it was observed that the intensity of the laser emission dropped by 62% after 5 min of operation. These results showed that these solid state flexible lasers are easy to fabricate and can be integrated into novel flexible photonic devices and novel photonic sensors.

  15. Pump as Turbine (PAT Design in Water Distribution Network by System Effectiveness

    Directory of Open Access Journals (Sweden)

    Oreste Fecarotta

    2013-08-01

    Full Text Available Water distribution networks face several problems related to leakages, where the pressure control strategy is a common practice for water loss management. Small-scale hydropower schemes, where pumps as turbines replace pressure reducing valves, can be considered an interesting technical solution, which ensures both economic convenience and system flexibility. Due to the water networks’ variable operating conditions, a new methodology to model the effectiveness of pumps as turbines was developed based on the efficiency and the mechanical reliability of the hydropower device and the flexibility of the plant. System effectiveness is proposed as the objective function in the optimization procedure and applied to a real system, enabling one to emphasize that the hydraulic regulation mode of the plant is better than the electric regulation mode for American Petroleum Industry (API manufacturing standards of pumps.

  16. 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.

  17. Reduction of the suction losses through reed valves in hermetic reciprocating compressors using a magnet coil

    Science.gov (United States)

    Hopfgartner, J.; Posch, S.; Zuber, B.; Almbauer, R.; Krischan, K.; Stangl, S.

    2017-08-01

    Reed valves are widely used in hermetic reciprocating compressors and are responsible for a large part of the thermodynamic losses. Especially, the suction valve, which is opened nearly during the whole suction stroke, has a big potential for improvement. Usually, suction valves are opened only by vacuum created by the moving piston and should be closed before the compression stroke starts to avoid a reversed mass-flow through the valve. Therefore, the valves are prestressed, which results on the other hand in a higher flow resistance. In this work, a suction valve is investigated, which is not closed by the preload of the valve but by an electromagnetic coil located in the suction muffler neck. Shortly before the piston reaches its bottom dead centre, voltage is applied to the coil and a magnetic force is generated which pulls the valve shut. Thereby, the flow resistance through the valve can be reduced by changing the preload on the reed valve because it is no longer needed to close the valve. The investigation of this adapted valve and the electromagnetic coil is firstly done by numerical simulations including fluid structure interactions of the reed valves of a reciprocating compressor and secondly by experiments made on a calorimeter test bench.

  18. Influence of saturation degree and role of suction in unsaturated soils behaviour: application to liquefaction

    Directory of Open Access Journals (Sweden)

    Vernay Mathilde

    2016-01-01

    Full Text Available The effect of the pore fluid compressibility on liquefaction has been studied by various authors. But few papers have been published about the role of suction in cyclic behavior of unsaturated soils. Most of these works use Skempton coefficient B as a reference in terms of saturation degree to analyze their results. The use of B in experimental conditions is convenient, but is not accurate when studying liquefaction behavior, since effects of suction are neglected. In this paper, the influence of saturation degree on mechanical behavior of a soil under dynamic loads is studied. Cyclic undrained triaxial tests were performed on sand samples, under various levels of saturation. Soil-water characteristic curve was used, in order to study influence of suction. The first results confirm that when the degree of saturation decreases, the resistance increases. Initial positive suction tends to stiffen the soil. It also appears that the presence of air delays the occurrence of liquefaction, but doesn’t prevent it. Indeed, liquefaction is observed, whether the soil is saturated or not.

  19. 78 FR 20316 - Final Issuance of General NPDES Permits (GP) for Small Suction Dredges in Idaho

    Science.gov (United States)

    2013-04-04

    ... System (NPDES) General Permit (IDG-37-0000) to placer mining operations in Idaho for small suction... Small Suction Dredges in Idaho AGENCY: Environmental Protection Agency, Region 10. ACTION: Final notice... significant economic impact on a substantial number of small entities.'' EPA has concluded that NPDES general...

  20. Development of advanced stability theory suction prediction techniques for laminar flow control. [on swept wings

    Science.gov (United States)

    Srokowski, A. J.

    1978-01-01

    The problem of obtaining accurate estimates of suction requirements on swept laminar flow control wings was discussed. A fast accurate computer code developed to predict suction requirements by integrating disturbance amplification rates was described. Assumptions and approximations used in the present computer code are examined in light of flow conditions on the swept wing which may limit their validity.

  1. A Report on Deliverable Three: Determine a Standard Performance Test for Military Suction Device Use

    Science.gov (United States)

    2017-09-20

    evaluating device suction while either wetted or completely immersed is highly important to predict performance in battlefield scenarios. Summary...mechanical, electrical, and environmental. OBJECTIVE: Research and review current test methods outlined in ISO 10079 and published journal articles...of contemporary oropharyngeal suction. The American journal of emergency medicine 17, 611- 613 (1999). 4. Hodgetts, T., Mahoney, P., Evans, G

  2. Optically pumped terahertz sources

    Institute of Scientific and Technical Information of China (English)

    ZHONG Kai; SHI Wei; XU DeGang; LIU PengXiang; WANG YuYe; MEI JiaLin; YAN Chao; FU ShiJie; YAO JianQuan

    2017-01-01

    High-power terahertz (THz) generation in the frequency range of0.1-10 THz has been a fast-developing research area ever since the beginning of the THz boom two decades ago,enabling new technological breakthroughs in spectroscopy,communication,imaging,etc.By using optical (laser) pumping methods with near-or mid-infrared (IR) lasers,flexible and practical THz sources covering the whole THz range can be realized to overcome the shortage of electronic THz sources and now they are playing important roles in THz science and technology.This paper overviews various optically pumped THz sources,including femtosecond laser based ultrafast broadband THz generation,monochromatic widely tunable THz generation,single-mode on-chip THz source from photomixing,and the traditional powerful THz gas lasers.Full descriptions from basic principles to the latest progress are presented and their advantages and disadvantages are discussed as well.It is expected that this review gives a comprehensive reference to researchers in this area and additionally helps newcomers to quickly gain understanding of optically pumped THz sources.

  3. The use of IV-tubing as a closed-suction drainage system during neurosurgical cases in Tanzania.

    Science.gov (United States)

    Bonfield, Christopher M; Shabani, Hamisi K; Kanumba, Emmanuel S; Ellegala, Dilantha B; Nicholas, Joyce

    2013-01-01

    Commercial closed-suctions drainage systems are commonly used in the United States and many other countries for use in neurosurgical cases. However, in Tanzania and other developing nations with fewer resources, these are not available. This report explores another option for a closed-system drainage system utilizing inexpensive supplies found commonly in hospitals around the world. Sterile IV-tubing is cut, inserted into the wound, and brought out through an adjacent puncture incision. For suction, an empty plastic bottle can be attached to the tubing. The IV-tubing closed-suction drainage system was applied in both cranial and spinal neurosurgical procedures, including as subdural, subgaleal, epidural, and suprafacial drains. It maintained suction and was an adequate substitute when commercial drains are unavailable. This report illustrates how sterile IV-tubing can be adapted for use as a closed-drainage system. It utilizes inexpensive supplies commonly found in many hospitals throughout the world and can be applied to both cranial and spinal neurosurgical procedures.

  4. Study and application of boiling water reactor jet pump characteristic

    International Nuclear Information System (INIS)

    Liao Lihyih

    1992-01-01

    RELAP5/MOD2 is an advanced thermal-hydraulic computer code used to analyze plant response to postulated transient and loss-of-coolant accidents in light water nuclear reactors. Since this computer code was originally developed for pressurized water reactor transient analysis, some of its capabilities are questioned when the methods are applied to a boiling water reactor. One of the areas which requires careful assessment is the jet pump model. In this paper, the jet pump models of RELAP5/MOD2, RETRAN-02/MOD3, and RELAP4/MOD3 are compared. From an investigation of the momentum equations, it is found that the jet pump models of these codes are not exactly the same. However, the effects of the jet pump models on the M-N characteristic curve are negligible. In this study, it is found that the relationship between the flow ratio, M, and the head ratio, N, is uniquely determined for a given jet pump geometry provided that the wall friction and gravitational head are neglected. In other words, under the given assumptions, the M-N characteristic curve will not change with power, level, recirculation pump speed or loop flow rate. When the effects of wall friction and gravitational head are included, the shape of the M-N curve will change. For certain conditions, the slope of the M-N curve can even change from negative to positive. The changes in the M-N curve caused by the separate effects of the wall friction and gravitational head will be presented. Sensitivity studies on the drive flow nozzle form loss coefficients, K d , the suction flow junction form loss coefficients, K s , the diffuser form loss coefficient, K c , and the ratio of different flow areas in the jet pump are performed. Finally, useful guidelines will be presented for plants without a plant specific M-N curve. (orig.)

  5. Numerical simulation and performance prediction in multi-stage submersible centrifugal pump

    International Nuclear Information System (INIS)

    Wang, W J; Li, G D; Wang, Y; Cui, Y R; Yin, G; Peng, S

    2013-01-01

    In order to study the inner flow field of multi-stage submersible centrifugal pump, the model named QD3-60/4-1.1 was selected. Steady turbulence characteristics of impellers, diffusers and return channel were calculated by Fluent software, the SIMPLEC algorithm and RNG κ-ε turbulence model with sliding mesh technology. Then, the distributions of pressure, velocity and Turbulence kinetic energy was obtained and the distributions of velocity field of a channel were analysed. The results show that the static pressure in impeller is increasing with the increasing of radius. The circumferential component of relative velocity is in the opposite direction of impeller rotating. At the same radius, the component value of pressure surface is larger than suction surface. With the increasing of flow rate, absolute velocity and relative velocity flow angle are becoming small, in opposite of the relative velocity and absolute velocity flow angle. The high turbulent zone of impeller is located in the gap of impellers and diffusers. Flow similarity and structure similarity of the multi-stage submersible pump are confirmed

  6. Dynamic exergoeconomic analysis of a heat pump system used for ancillary services in an integrated energy system

    DEFF Research Database (Denmark)

    Meesenburg, Wiebke; Ommen, Torben; Elmegaard, Brian

    2018-01-01

    the cost of heat and flexibility products based on the difference in exergy destruction was proposed. The method was applied to a case of a groundwater-source heat pump system supplying a district heating island system. It was found that providing demand flexibility causes higher exergy destruction, mainly...... due to heat losses during storage and the need to reheat the fluid using an electric heater. The major part of the additional exergy destruction was not related to heat pump regulation. When providing flexibility the overall cost of the system increased and according to the proposed allocation, demand...

  7. CFD Analysis of a Centrifugal Pump with Supercritical Carbon Dioxide as a Working Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Gu; Lee, Jeong Ik; Ahn, Yoonhan; Lee, Jekyoung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Cha, Jae Eun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Addad, Yacine [Khalifa Univ. of Science Technology and Research, Abu Dhabi (United Arab Emirates)

    2013-05-15

    The research team is conducting a S-CO{sub 2} pump experiment to obtain fundamental data for the advanced pump design and measure the overall performance of the pump near the critical point. The S-CO{sub 2} pump testing loop configuration is similar to SNL and JAEA testing loop while the operating conditions and focus of experiment are different from other test facilities. This paper presents the methodology of a 3-dimensional flow analysis for the S-CO{sub 2} pump by using the commercial CFD code. In Figure 2, the results at the 1.5kg/s mass flow rate seems to be close agreement between the CFD efficiency and S-CO{sub 2} test results. In the low mass flow rate of 1.0kg/s, CFD predicted 17∼25% higher efficiency than the test result. In the real test facility, the steel structure of pump is not an adiabatic wall and also the mechanical losses such as suction, blade loading and leakage exist in the pump. The reason why CFD analysis showed higher pump efficiency at the low mass flow is the above mentioned losses were excluded from the model. However, as the mass flow rate increases these have less effect on the efficiency. If the heat transfer through the structure and pump losses are applied in the analysis, other losses can be estimated. From the S-CO{sub 2} pump experiment, more data will be obtained and compared to the CFD analyses under the methodology presented in this paper. After the fluid behavior in the pump are well understood, these analysis results will be used for optimizing impeller for advanced S-CO{sub 2} compressor design in the future. However, it is very encouraging that even at very small mass flow rate the efficiency of S-CO{sub 2} pump near the critical point operation is very high compared to the manufacturer water test. The reason behind such phenomenon will be more carefully studied in the future.

  8. Deriving the suction stress of unsaturated soils from water retention curve, based on wetted surface area in pores

    Science.gov (United States)

    Greco, Roberto; Gargano, Rudy

    2016-04-01

    The evaluation of suction stress in unsaturated soils has important implications in several practical applications. Suction stress affects soil aggregate stability and soil erosion. Furthermore, the equilibrium of shallow unsaturated soil deposits along steep slopes is often possible only thanks to the contribution of suction to soil effective stress. Experimental evidence, as well as theoretical arguments, shows that suction stress is a nonlinear function of matric suction. The relationship expressing the dependence of suction stress on soil matric suction is usually indicated as Soil Stress Characteristic Curve (SSCC). In this study, a novel equation for the evaluation of the suction stress of an unsaturated soil is proposed, assuming that the exchange of stress between soil water and solid particles occurs only through the part of the surface of the solid particles which is in direct contact with water. The proposed equation, based only upon geometric considerations related to soil pore-size distribution, allows to easily derive the SSCC from the water retention curve (SWRC), with the assignment of two additional parameters. The first parameter, representing the projection of the external surface area of the soil over a generic plane surface, can be reasonably estimated from the residual water content of the soil. The second parameter, indicated as H0, is the water potential, below which adsorption significantly contributes to water retention. For the experimental verification of the proposed approach such a parameter is considered as a fitting parameter. The proposed equation is applied to the interpretation of suction stress experimental data, taken from the literature, spanning over a wide range of soil textures. The obtained results show that in all cases the proposed relationships closely reproduces the experimental data, performing better than other currently used expressions. The obtained results also show that the adopted values of the parameter H0

  9. Experimental study on occurrence-time ratio measurements of air entrainment in a suction sump

    International Nuclear Information System (INIS)

    Inagaki, K; Funaki, J; Hirata, K

    2009-01-01

    In order to get accurate measurements of air entrainment in a suction sump, we design some new simple bubble sensors, which can detect the existence of air bubbles inside a suction pipe with no disturbances by the sensors and with a fine spatial resolution. We force on an intermittency factor γ, that is, an occurrence-time ratio of the air entrainment, and compare the result by the present sensor with those by conventional two methods; namely, visual and auditory ones. As a result, we show the criteria which specify lower-accuracy conditions in the conventional methods. By the visual method, the accuracy of the γ becomes low, when γ is less than 0.05. By the auditory method, the accuracy of γ becomes low, when the submergence depth S of the suction pipe is close to the critical one S c .

  10. Operational experience with double acting piston pumps for cryogenic helium and nitrogen

    International Nuclear Information System (INIS)

    Vosswinkel, F.

    1978-01-01

    The design of a high efficiency double acting piston pump suitable for pumping liquefied gases at cryogenic temperatures for cable cooling, is reported. The pump has proved flexible, reliable and efficient in operation. The plunger-type pumps can be used for filling cryostats or dewars with liquid helium or nitrogen from a pressure free or pressurized storage vessel, or as circulators for subcooled, saturated and/or supercritical helium in large scale cooling experiments. Flow rates of up to 17 g/s, maximum operating pressure of 600 kPa absolute and maximum differential pressure of approximately 100 kPa are obtained. (UK)

  11. Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation: SIMPLE.

    Science.gov (United States)

    Kokalj, Tadej; Park, Younggeun; Vencelj, Matjaž; Jenko, Monika; Lee, Luke P

    2014-11-21

    Reliable, autonomous, internally self-powered microfluidic pumps are in critical demand for rapid point-of-care (POC) devices, integrated molecular-diagnostic platforms, and drug delivery systems. Here we report on a Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation (SIMPLE), which is disposable, autonomous, easy to use and fabricate, robust, and cost efficient, as a solution for self-powered microfluidic POC devices. The imbibition pump introduces the working liquid which is sucked into a porous material (paper) upon activation. The suction of the working liquid creates a reduced pressure in the analytical channel and induces the sequential sample flow into the microfluidic circuits. It requires no external power or control and can be simply activated by a fingertip press. The flow rate can be programmed by defining the shape of utilized porous material: by using three different paper shapes with circular section angles 20°, 40° and 60°, three different volume flow rates of 0.07 μL s(-1), 0.12 μL s(-1) and 0.17 μL s(-1) are demonstrated at 200 μm × 600 μm channel cross-section. We established the SIMPLE pumping of 17 μL of sample; however, the sample volume can be increased to several hundreds of μL. To demonstrate the design, fabrication, and characterization of SIMPLE, we used a simple, robust and cheap foil-laminating fabrication technique. The SIMPLE can be integrated into hydrophilic or hydrophobic materials-based microfluidic POC devices. Since it is also applicable to large-scale manufacturing processes, we anticipate that a new chapter of a cost effective, disposable, autonomous POC diagnostic chip is addressed with this technical innovation.

  12. Improved Suction Technique for the Characterization of Construction Materials

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht; Hansen, Kurt Kielsgaard

    2007-01-01

    The suction technique is a method from soil science that is used for the study of moisture storage capacity in porous construction materials at high relative humidity levels (above approximately 93%). The samples to be studied are placed in a pressurized container (an extractor) on a water...

  13. Management of insulin pump therapy in children with type 1 diabetes.

    Science.gov (United States)

    Abdullah, Nadeem; Pesterfield, Claire; Elleri, Daniela; Dunger, David B

    2014-12-01

    Insulin pump therapy is a current treatment option for children and adolescents with type 1 diabetes. Insulin pumps can provide a greater flexibility in insulin administration and meal planning, as compared with multiple insulin injections, and they may be particularly suitable for the paediatric age group. Many young people with diabetes have integrated insulin pumps into their daily practice. The use of insulin pumps can also be supplemented by the information retrieved from continuous glucose monitoring in the sensor-augmented pump therapy, which may improve glycaemic control. In this review, we describe the principles of pump therapy and summarise features of commercially available insulin pumps, with focus on practical management and the advantages and disadvantages of this technology. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Parametric study of a capillary tube-suction line heat exchanger in a transcritical CO2 heat pump cycle

    International Nuclear Information System (INIS)

    Agrawal, Neeraj; Bhattacharyya, Souvik

    2008-01-01

    The capillary tube in a transcritical CO 2 system behaves differently as temperature and pressure are two independent parameters unlike those in a sub-critical cycle. A capillary tube-suction line heat exchanger (CL-SLHX) in a transcritical vapour compression cycle considering homogeneous two-phase flow is modelled in this study based on mass, energy and momentum equations. Effects of gas cooler temperature, evaporator temperature and internal diameter of capillary tube are investigated. Heat transfer rate is observed to be influenced by refrigerant quality, mass flow rate and the prevailing temperature difference. Heat transfer rate variation with gas cooler temperature is unique, recording an initial increase followed by a decrease. Frictional pressure drop influences the heat transfer; consequently, chances of re-condensation of refrigerant vapour are very marginal. Larger diameter of capillary tube leads to increase in refrigerant mass flow rate and increase in heat transfer rate as well. Shorter inlet adiabatic capillary length with larger heat exchanger length is better for heat transfer. This study is an attempt to dispel the scepticism prevailing in transcritical CO 2 system community overemphasising the need for a throttle valve to control the optimum discharge pressure

  15. Flexibility in Flood Management Design: Proactive Planning Under Climate Change Uncertainty

    Science.gov (United States)

    Smet, K.; de Neufville, R.; van der Vlist, M.

    2015-12-01

    This paper presents an innovative, value-enhancing procedure for effective planning and design of long-lived flood management infrastructure given uncertain future flooding threats due to climate change. Designing infrastructure that can be adapted over time is a method to safeguard the efficacy of current design decisions given uncertainty about rates and future impacts of climate change. This paper explores the value of embedding "options" in a physical structure, where an option is the right but not the obligation to do something at a later date (e.g. over-dimensioning a floodwall foundation now facilitates a future height addition in response to observed increases in sea level; building of extra pump bays in a pumping station now enables the addition of pumping capacity whenever increased precipitation warrants an expansion.) The proposed procedure couples a simulation model that captures future climate induced changes to the hydrologic operating environment of a structure, with an economic model that estimates the lifetime economic performance of alternative investments. The economic model uses Real "In" Options analysis, a type of cash flow analysis that quantifies the implicit value of options and the flexibility they provide. This procedure is demonstrated using replacement planning for the multi-functional pumping station IJmuiden on the North Sea Canal in the Netherlands. Flexibility in design decisions is modelled, varying the size and specific options included in the new structure. Results indicate that the incorporation of options within the structural design has the potential to improve its economic performance, as compared to more traditional, "build it once and build it big" designs where flexibility is not an explicit design criterion. The added value resulting from the incorporation of flexibility varies with the range of future conditions considered, as well as the options examined. This procedure could be applied more broadly to explore

  16. Acceptance test procedure, 241-SY-101 Flexible Receiver System, Phase III testing

    International Nuclear Information System (INIS)

    Ritter, G.A.

    1994-01-01

    This Acceptance Test Procedure is for the 241-SY-101 Flexible Receiver System, Phase III Testing. This procedure will test the sealing integrity of the Flexible Receiver System to ensure that release of waste and aerosols will be minimized during the removal of the test mixer pump from tank SY-101

  17. The effect of peer support in adults with insulin pump-treated type 1 diabetes: a pilot study of a flexible and participatory intervention

    Directory of Open Access Journals (Sweden)

    Joensen LE

    2017-11-01

    Full Text Available Lene Eide Joensen,1 Merete Meldgaard Andersen,2 Sabrina Jensen,1 Kirsten Nørgaard,2 Ingrid Willaing1 1Diabetes Management Research, Steno Diabetes Center Copenhagen, Gentofte, 2Department of Endocrinology, Hvidovre Hospital, Hvidovre, Denmark Aim: The aim of this study was to explore the effects of a flexible and participatory peer support intervention in a clinical setting for adults with type 1 diabetes treated with an insulin pump, focusing on enhancing diabetes-specific social capital. The key questions were as follows: 1 what effects are appropriate to expect, according to participants? and 2 to what extent did these effects occur? Methods: Two peer support intervention programs were conducted in a diabetes specialist clinic (N=30. A participatory and adaptable approach allowed flexibility in the content of peer support meetings, which were facilitated by a diabetes nurse. Individual interviews explored participants’ perception of effects of the intervention. Interview data were analyzed qualitatively. Participants (n=27 completed a baseline and postintervention questionnaire that included items assessing diabetes empowerment, diabetes distress, diabetes-specific social support, and diabetes loneliness. HbA1c levels were compared before and after the intervention. Results: Participants experienced enhanced diabetes-specific social capital, diabetes motivation, awareness of personal diabetes practices, and serenity and openness in life with diabetes. They also became more aware of treatment and support possibilities. Negative effects included feeling sad or upset after the meetings or feeling different than and not as well-controlled as other participants. Quantitative analyses showed enhanced social support, decreased eating distress and trends toward enhanced diabetes empowerment, decreased diabetes loneliness, and decreased diabetes distress (powerlessness. We found fewer positive and/or negative outcomes among participants who felt

  18. Radon Sub-slab Suctioning System Integrated in Insulating Layer

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    This poster presents a new radon sub-slab suctioning system. This system makes use of a grid of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground floor slab. For this purpose a new system of prefabricated lightweight elements is introduced...

  19. Alternative Shape of Suction Caisson to Reduce Risk of Buckling under high Pressure

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2013-01-01

    Using large suction caissons for offshore wind turbines is an upcoming technology also referred to as bucket foundations. During operation the bucket foundation is loaded by a large overturning moment from the wind turbine and the wave loads. However, during installation the bucket is loaded...... cylindrical monopod foundation made of steel. In this paper, an alternative design/shape of the suction caisson, having a smaller risk of buckling under high pressure is presented. The risk of structural buckling is addressed using numerical methods to determine the buckling pressures of the re...

  20. Dome shaped micro-laser encapsulated in a flexible film

    International Nuclear Information System (INIS)

    Ioppolo, T; Manzo, M

    2014-01-01

    In this paper, we demonstrated multimode laser emission from a dome shaped micro-scale resonator encapsulated in a flexible polymer film. The resonator with a radius of ∼60 microns was made of Norland Blocking Adhesive (NBA 107) doped with a solution of rhodamine 6G and ethanol. The dome was encapsulated in a flexible polymeric film made of polydymethylsiloxane (PDMS) with a thickness of 1 mm. The micro-scale laser was optically pumped using a frequency doubled Q-switch Nd:YAG laser with pulse repetition of 10 Hz and pulse duration of 9 ns. Experiments were carried out to investigate the lasing properties of this laser structure. The pumping threshold for multimode laser emission was below 100 µJ cm −2 . The average optical quality factor for all observed laser modes was of the order of 10 4 . Using a fluence of 315.8 µJ cm −2 it was observed that the intensity of the laser emission dropped by 62% after 5 min of operation. These results showed that these solid state flexible lasers are easy to fabricate and can be integrated into novel flexible photonic devices and novel photonic sensors. (paper)

  1. Heat pumps in combined heat and power systems

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    2014-01-01

    Heat pumps have previously been proposed as a way to integrate higher amounts of renewable energy in DH (district heating) networks by integrating, e.g., wind power. The paper identifies and compares five generic configurations of heat pumps in DH systems. The operational performance...... of the considered cases. When considering a case where the heat pump is located at a CHP (combined heat and power) plant, a configuration that increases the DH return temperature proposes the lowest operation cost, as low as 12 EUR MWh-1 for a 90 °C e 40 °C DH network. Considering the volumetric heating capacity......, a third configuration is superior in all cases. Finally, the three most promising heat pump configurations are integrated in a modified PQ-diagram of the CHP plant. Each show individual advantages, and for two, also disadvantages in order to achieve flexible operation....

  2. Self-Calibrating, Variable-Flow Pumping System

    Science.gov (United States)

    Walls, Joe T.

    1994-01-01

    Pumping system provides accurate, controlled flows of two chemical liquids mixed in spray head and react to form rigid or flexible polyurethane or polyisocyanurate foam. Compatible with currently used polyurethane-based coating materials and gas-bubble-forming agents (called "blowing agents" in industry) and expected to be compatible with materials that used in near future. Handles environmentally acceptable substitutes for chlorofluorocarbon foaming agents.

  3. Flow in water-intake pump bays: A guide for utility engineers. Final report

    International Nuclear Information System (INIS)

    Ettema, R.

    1998-09-01

    This report is intended to serve as a guide for power-plant engineers facing problems with flow conditions in pump bays in water-intake structures, especially those located alongside rivers. The guide briefly introduces the typical prevailing flow field outside of a riverside water intake. That flow field often sets the inflow conditions for pump bays located within the water intake. The monograph then presents and discusses the main flow problems associated with pump bays. The problems usually revolve around the formation of troublesome vortices. A novel feature of this monograph is the use of numerical modeling to reveal diagnostically how the vortices form and their sensitivities to flow conditions, such as uniformity of approach flow entering the bay and water-surface elevation relative to pump-bell submergence. The modeling was carried out using a computer code developed specially for the present project. Pump-bay layouts are discussed next. The discussion begins with a summary of the main variables influencing bay flows. The numerical model is used to determine the sensitivities of the vortices to variations in the geometric parameters. The fixes include the use of flow-control vanes and suction scoops for ensuring satisfactory flow performance in severe flow conditions; notably flows with strong cross flow and shallow flows. The monograph ends with descriptions of modeling techniques. An extensive discussion is provided on the use of numerical model for illuminating bay flows. The model is used to show how fluid viscosity affects bay flow. The effect of fluid viscosity is an important consideration in hydraulic modeling of water intakes

  4. A Constitutive Model for Unsaturated soils based on a Compressibility Framework dependent on Suction and Degree of Saturation

    Directory of Open Access Journals (Sweden)

    Sitarenios Panagiotis

    2016-01-01

    Full Text Available The Modified Cam Clay model is extended to account for the behaviour of unsaturated soils using Bishop’s stress. To describe the Loading – Collapse behaviour, the model incorporates a compressibility framework with suction and degree of saturation dependent compression lines. For simplicity, the present paper describes the model in the triaxial stress space with characteristic simulations of constant suction compression and triaxial tests, as well as wetting tests. The model reproduces an evolving post yield compressibility under constant suction compression, and thus, can adequately describe a maximum of collapse.

  5. Test plan for qualification testing of the 241-SY-101 Flexible Receiver System

    International Nuclear Information System (INIS)

    Ritter, G.A.

    1994-01-01

    A mixer pump was installed in tank 241-SY-101 on July 3, 1993, to support hydrogen mitigation testing. This test mixer pump has proven to be very successful in mitigating the large gas releases, or ''burps,'' from the tank waste. Therefore, a decision has been made to fabricate a spare pump that will be installed upon failure of the existing test pump. Before replacement activities can be initiated, equipment must be available to remove the existing pump. A pump removal system is currently being designed and fabricated that will support the retrieval, transportation and disposal of the existing pump. The Equipment Removal System consists of six major components: the flexible receiver system (FRS), the equipment storage container, the container strongback system, the container transport trailer, the support cranes, and the pump washdown system

  6. Maximizing Storage Flexibility in an Aggregated Heat Pump Portfolio

    DEFF Research Database (Denmark)

    Pedersen, Tom S.; Nielsen, Kirsten M.; Andersen, Palle

    2014-01-01

    for storage capability. It is of great importance to move energy consumption in time to balance the grid. In this paper a portfolio of houses are modelled and controlled using an aggregated model and a model free scheduling algorithm. Flexibility and ability to trade on the intra-day regulating market...

  7. Numerical Investigation of Wall Cooling and Suction Effects on Supersonic Flat-Plate Boundary Layer Transition Using Large Eddy Simulation

    Directory of Open Access Journals (Sweden)

    Suozhu Wang

    2015-02-01

    Full Text Available Reducing friction resistance and aerodynamic heating has important engineering significance to improve the performances of super/hypersonic aircraft, so the purpose of transition control and turbulent drag reduction becomes one of the cutting edges in turbulence research. In order to investigate the influences of wall cooling and suction on the transition process and fully developed turbulence, the large eddy simulation of spatially evolving supersonic boundary layer transition over a flat-plate with freestream Mach number 4.5 at different wall temperature and suction intensity is performed in the present work. It is found that the wall cooling and suction are capable of changing the mean velocity profile within the boundary layer and improving the stability of the flow field, thus delaying the onset of the spatial transition process. The transition control will become more effective as the wall temperature decreases, while there is an optimal wall suction intensity under the given conditions. Moreover, the development of large-scale coherent structures can be suppressed effectively via wall cooling, but wall suction has no influence.

  8. Analysis of Infiltration-Suction Response in Unsaturated Residual Soil Slope in Gelugor, Penang

    Science.gov (United States)

    Ashraf Mohamad Ismail, Mohd; Hasliza Hamzah, Nur; Min, Ng Soon; Hazreek Zainal Abidin, Mohd; Tajudin, Saiful Azhar Ahmad; Madun, Aziman

    2018-04-01

    Rainfall infiltration on residual soil slope may impair slope stability by altering the pore-water pressure in the soil. A study has been carried out on unsaturated residual soil slope in Gelugor, Penang to determine the changes in matric suction of residual soils at different depth due to rainwater infiltration. The sequence of this study includes the site investigation, field instrumentation, laboratory experiment and numerical modeling. Void ratio and porosity of soil were found to be decreasing with depth while the bulk density and dry density of soil increased due to lower porosity of soil at greater depth. Soil infiltration rate and matric suction of all depths decrease with the increase of volumetric water content as well as the degree of saturation. Numerical modeling was used to verify and predict the relationship between infiltration-suction response and degree of saturation. Numerical models can be used to integrate the rainfall scenarios into quantitative landslide hazard assessments. Thus, development plans and mitigation measures can be designed for estimated impacts from hazard assessments based on collected data.

  9. Acceptance test report, 241-SY-101 Flexible Receiver System, Phase 3 testing

    International Nuclear Information System (INIS)

    Ritter, G.A.

    1995-01-01

    This document summarizes the results of the phase 3 acceptance test of the 241-SY-101 Flexible Receiver System (FRS). The purpose of this acceptance test is to verify the sealing integrity of the FRS to ensure that the release of waste and aerosols will be minimized during the removal of the test mixer pump from Tank 241-SY-101. The FRS is one of six major components of the Equipment Removal System, which has been designed to retrieve, transport, and store the mixer pump. This acceptance test was performed at the 306E Facility in the 300 area from January 10, 1995 to January 17, 1995. The Phase 3 test consisted of two parts. Part one was a water leak test of the seal between the blast shield and mock load distribution frame (LDF) to ensure that significant contamination of the pump pit and waste interaction with the aluminum impact-limiting material under the LDF are prevented during the pump removal operation. The second part of this acceptance test was an air leak test of the assembled flexible receiver system. The purpose of this test was to verify that the release of hazardous aerosols will be minimized if the tank dome pressure becomes slightly positive during the decontamination of the mixer pump

  10. Wind power integration with heat pumps, heat storages, and electric vehicles – Energy systems analysis and modelling

    DEFF Research Database (Denmark)

    Hedegaard, Karsten

    The fluctuating and only partly predictable nature of wind challenges an effective integration of large wind power penetrations. This PhD thesis investigates to which extent heat pumps, heat storages, and electric vehicles can support the integration of wind power. Considering the gaps in existing...... in an energy system context. Energy systems analyses reveal that the heat pumps can even without flexible operation contribute significantly to facilitating larger wind power investments and reducing system costs, fuel consumption, and CO2 emissions. When equipping the heat pumps with heat storages, only...... moderate additional benefits are achieved. Hereof, the main benefit is that the need for investing in peak/reserve capacities can be reduced through peak load shaving. It is more important to ensure flexible operation of electric vehicles than of individual heat pumps, due to differences in the load...

  11. Effects of air flow maldistribution on refrigeration system dynamics of air source heat pump chiller under frosting conditions

    International Nuclear Information System (INIS)

    Gong Jianying; Gao Tieyu; Yuan Xiuling; Huang Dong

    2008-01-01

    The effects of air flow maldistribution on the performance of an air source heat pump chiller under frosting conditions were investigated experimentally. The results indicated that air flow maldistribution was the dominant factor leading to hunting of the thermostatic expansion valve for medium and/or large size finned tube evaporators. With air flow maldistribution degree (AMD) increasing, frost occurred earlier, and the frost layer grew faster. The operating characteristics became lower when AMD was increased. We found such phenomenon seemed to be related to both the difference of refrigerant outlet superheat and the frosting velocity. In the hunting stage, the frost block effect became the main factor degrading the refrigeration system performance. With AMD increasing, the heat pump system pertinent performance data (suction pressure, evaporation temperature, discharge pressure, refrigerant outlet temperature, etc.) were degraded more dramatically

  12. Frequency Response of Near-Wall Coherent Structures to Localized Periodic Blowing and Suction in Turbulent Boundary Layer

    International Nuclear Information System (INIS)

    Jian-Hua, Liu; Nan, Jiang

    2008-01-01

    We experimentally investigate the frequency response of near-wall coherent structures to localized periodic blowing and suction through a spanwise slot in a turbulent boundary layer by changing the frequency of periodic disturbance at similar velocities of free stream. The effects of blowing and suction disturbance on energy redistribution, turbulent intensity u' rms + , over y + and waveforms of phase-averaged velocity during sweeping process are respectively discussed under three frequencies of periodic blowing and suction in near-wall region of turbulent boundary layer, compared with those in a standard turbulent boundary layer. The most effective disturbance frequency is figured out in this system. (fundamental areas of phenomenology (including applications))

  13. Experimental study of enhancing heating performance of the air-source heat pump by using a novel heat recovery device designed for reusing the energy of the compressor shell

    International Nuclear Information System (INIS)

    Huang, Bi; Jian, Qifei; Luo, Lizhong; Zhao, Jing

    2017-01-01

    Highlights: • A novel heat recovery device was designed and tested. • Aiming at avoiding liquid slugging in cold areas. • Recovery of the waste energy of compressor housing. • Refrigerant is heated with the energy recovered before it is sucked into the compressor. • Requires no extra power while the recovery system is operating. - Abstract: A novel heat recovery device designed to recover the heat that is released from the outer surface of heat pump compressors, and to enhance the performance of heat pumps in cold areas was made and tested in this study. The novel heat recovery device consists of three fundamental units: a heat absorption unit, a heat emission unit and heat pipes. An amount of work focused on recovering the heat of compressors through oil system, but few studies concentrated on the housing. The main advantage of the heat recovery device is no need for extra energy consumption for its only driving force is the temperature difference between the compressor shell and the working fluid inside the suction line. The experimental results were obtained from a series of tests with a R410A air-source heat pump. Effects of the device are analyzed with respect of the suction temperature, temperature distribution among the housing, input power and exergy destruction. Moreover, the impact on the heating capacity is also discussed. Further, direction for improvement is also given based on the analysis.

  14. MHD flow over a permeable stretching/shrinking sheet of a nanofluid with suction/injection

    Directory of Open Access Journals (Sweden)

    Sandeep Naramgari

    2016-06-01

    Full Text Available In this study we analyzed the influence of thermal radiation and chemical reaction on two dimensional steady magnetohydrodynamic flow of a nanofluid past a permeable stretching/shrinking sheet in the presence of suction/injection. We considered nanofluid volume fraction on the boundary is submissive controlled, which makes the present study entirely different from earlier studies and physically more realistic. The equations governing the flow are solved numerically. Effects of non-dimensional governing parameters on velocity, temperature and concentration profiles are discussed and presented through graphs. Also, coefficient of skin friction and local Nusselt number is investigated for stretching/shrinking and suction/injection cases separately and presented through tables. Comparisons with existed results are presented. Present results have an excellent agreement with the existed studies under some special assumptions. Results indicate that the enhancement in Brownian motion and thermophoresis parameters depreciates the nanoparticle concentration and increases the mass transfer rate. Dual solutions exist only for certain range of stretching/shrinking and suction/injection parameters.

  15. Tube suction test for evaluating durability of cementitiously stabilized soils.

    Science.gov (United States)

    2011-06-01

    In a comprehensive laboratory study, different tests namely, unconfined compressive strength (UCS) at the end of freeze-thaw/wet-dry (F-T/W-D) cycles, resilient modulus (Mr) at the end of F-T/W-D cycles, vacuum saturation, tube suction, and moisture ...

  16. Tube suction test for evaluating durability of cementitiously stabilized soils.

    Science.gov (United States)

    2011-06-01

    In a comprehensive laboratory study, different tests namely, unconfined compressive strength (UCS) at the end of freeze-thaw/wet-dry (FT/ : W-D) cycles, resilient modulus (Mr) at the end of F-T/W-D cycles, vacuum saturation, tube suction, and moistur...

  17. Centrifugal pump assembly for use in nuclear reactor plants or the like

    International Nuclear Information System (INIS)

    Honold, E.; Ruepp, M.

    1975-01-01

    A description is given of a vertical centrifugal pump assembly for use as a primary recirculating pump in a nuclear reactor plant which has an uppermost shaft which is driven by a motor, a lowermost shaft which drives the impeller of the pump, and an intermediate shaft which is movable axially between the uppermost and lowermost shafts and carries a housing for radial and/or thrust bearings. A rigid coupling between the lowermost shaft and the intermediate shaft is disengaged when the intermediate shaft is lifted to thereby afford access to certain parts of the lowermost shaft. The uppermost shaft can drive the intermediate shaft through the medium of a flexible coupling having coupling elements mounted on the lower end of the uppermost shaft and the upper end of the intermediate shaft, and a distancing sleeve whose internal threads are in permanent mesh with external threads of the two coupling elements. A shroud which surrounds the flexible coupling has a maximum-diameter tubular section rigid with the housing for the bearings, a minimum-diameter tubular section rigid with but detachable from the casing of the motor, and a median tubular section which penetrates into the maximum-diameter section when the intermediate shaft is lifted. When the minimum-diameter section is detached from the casing of the motor, it can be slid, together with the intermediate section, into the maximum-diameter section to thereby afford access to the flexible coupling. The rigid coupling has two coaxial coupling elements which are mounted at the upper end of the pump shaft and the lower end of the intermediate shaft and may have teeth which mate when the intermediate shaft assumes its lower end position in which it can drive the pump

  18. Safety System for Controlling Fluid Flow into a Suction Line

    Science.gov (United States)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)

    2018-01-01

    A safety system includes a sleeve fitted within a pool's suction line at its inlet. The sleeve terminates with a plate that resides within the suction line. The plate has holes formed therethrough. A housing defining distinct channels is fitted in the sleeve so that the distinct channels lie within the sleeve. Each of the distinct channels has a first opening on one end thereof and a second opening on another end thereof. The second openings reside in the sleeve. The first openings are in fluid communication with the water in the pool, and are distributed around a periphery of an area of the housing that prevents coverage of all the first openings when a human interacts therewith. A first sensor is coupled to the sleeve to sense pressure therein, and a second pressure sensor is coupled to the plate to sense pressure in one of the plates' holes.

  19. Flexible use of electricity in heat-only district heating plants

    Directory of Open Access Journals (Sweden)

    Erik Trømborg

    2017-01-01

    Full Text Available European energy systems are in a period of significant transition, with the increasing shares of variable renewable energy (VRE and less flexible fossil-based generation units as predominant factors. The supply-side changes are expected to cause large short-term electricity price volatility. More frequent periods of low electricity prices may mean that electric use in flexible heating systems will become more profitable, and such flexible heating systems may, in turn, improve the integration of increasing shares of VRE. The objective of this study is to analyze the likely future of Nordic electricity price levels and variations and how the expected prices might affect the use of electricity and thermal storage in heat-only district heating plants. We apply the North European energy market model Balmorel to provide scenarios for future hourly electricity prices in years with normal, high, and low inflow levels to the hydro power system. The simulation tool energyPRO is subsequently applied to quantify how these electricity price scenarios affect the hourly use of thermal storage and individual boilers in heat-only district heating plants located in Norway. The two studied example plants use wood chips or heat pump as base load representing common technologies for district heating in Norway. The Balmorel results show that annual differences in inflow is still a decisive factor for Norwegian and Nordic electricity prices in year 2030 and that short-term (daily price variability is expected to increase. In the plant-level simulations, we find that tank storage, which is currently installed in only a few district heating plants in Norway, is a profitable flexibility option that will significantly reduce the use of fossil peak load in both biomass and heat-pump-based systems. Installation of an electric boiler in addition to tank storage is profitable in the heat pump system due to the limited capacity of the heat pump. Electricity will hence, to a

  20. Vapor pressure lowering effects due to salinity and suction pressure in the depletion of vapor-dominated geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Battistelli, A. [Aquater S.p.A., Pisa (Italy); Calore, C. [Istituto Internazionale per le Ricerche Geotermiche-CNR, Pisa (Italy); Pruess, K. [Lawrence Berkeley Lab., Berkeley, CA (United States)

    1995-03-01

    The equation-of-state module able to handle saline brines with non-condensible gas, developed for the TOUGH2 simulator, has been improved to include vapor pressure lowering (VPL) due to suction pressure as represented by Kelvin`s equation. In this equation the effects of salt are considered whereas those of non-condensible gas have currently been neglected. Numerical simulations of fluid production from tight matrix blocks have been performed to evaluate the impact of VPL effects due to salinity and suction pressure on the depletion behaviour of vapor-dominated geothermal reservoirs. Previous studies performed neglected VPL due to suction pressure showed that for initial NaCl mass fractions above threshold values, {open_quotes}sealing{close_quotes} of the block occurs and large amounts of liquid fluid may not be recovered. On the other hand, below the threshold value the matrix block dries out due to fluid production. The inclusion of VPL due to suction pressure does not allow complete vaporization of the liquid phase. As a result, the threshold NaCl concentration above which sealing of the matrix block occurs is increased. Above the {open_quotes}critical{close_quotes} NaCl concentration, block depletion behaviour with and without the VPL due to suction pressure is almost identical, as liquid phase saturation remains high even after long production times. As the VPL due to suction pressure depends mainly on capillary pressure, the shape of capillary pressure functions used in numerical simulations is important in determining VPL effects on block depletion.

  1. Dynamic stiffness of suction caissons - torsion, sliding and rocking

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.; Andersen, Lars

    2006-12-15

    This report concerns the dynamic soil-structure interaction of steel suction caissons applied as foundations for offshore wind turbines. An emphasis is put on torsional vibrations and coupled sliding/rocking motion, and the influence of the foundation geometry and the properties of the surrounding soil is examined. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency-dependent coefficients corresponding to the different degrees of freedom. The dynamic stiffness coefficients for the skirted foundation are evaluated by means of a three-dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been carried out for different combinations of the skirt length and the Poisson's ratio of the subsoil. Finally, the high-frequency impedance has been determined for future use in lumped-parameter models of wind turbine foundations in aero-elastic codes. (au)

  2. BWR recirculation pump diagnostic expert system

    International Nuclear Information System (INIS)

    Chiang, S.C.; Morimoto, C.N.; Torres, M.R.

    2004-01-01

    At General Electric (GE), an on-line expert system to support maintenance decisions for BWR recirculation pumps for nuclear power plants has been developed. This diagnostic expert system is an interactive on-line system that furnishes diagnostic information concerning BWR recirculation pump operational problems. It effectively provides the recirculation pump diagnostic expertise in the plant control room continuously 24 hours a day. The expert system is interfaced to an on-line monitoring system, which uses existing plant sensors to acquire non-safety related data in real time. The expert system correlates and evaluates process data and vibration data by applying expert rules to determine the condition of a BWR recirculation pump system by applying knowledge based rules. Any diagnosis will be automatically displayed, indicating which pump may have a problem, the category of the problem, and the degree of concern expressed by the validity index and color hierarchy. The rules incorporate the expert knowledge from various technical sources such as plant experience, engineering principles, and published reports. These rules are installed in IF-THEN formats and the resulting truth values are also expressed in fuzzy terms and a certainty factor called a validity index. This GE Recirculation Pump Expert System uses industry-standard software, hardware, and network access to provide flexible interfaces with other possible data acquisition systems. Gensym G2 Real-Time Expert System is used for the expert shell and provides the graphical user interface, knowledge base, and inference engine capabilities. (author)

  3. Timer switch to convert suction apparatus for negative pressure wound therapy application

    Directory of Open Access Journals (Sweden)

    Surath Amarnath

    2014-01-01

    Full Text Available Background: Negative pressure wound therapy (NPWT is an established modality in the treatment of chronic wounds, open fractures, and post-operative wound problems. This method has not been widely used due to the high cost of equipment and consumables. This study demonstrates an indigenously developed apparatus which gives comparable results at a fraction of the cost. Readily available materials are used for the air-tight dressing. Materials and Methods: Equipment consists of suction apparatus with adjustable pressure valve set to a pressure 125-150 mmHg. An electronic timer switch with a sequential working time of 5 min and a standby time of 3 min provides the required intermittent negative pressure. Readily available materials such as polyvinyl alcohol sponge, suction drains and steridrapes were used to provide an air tight wound cover. Results: A total of 90 cases underwent 262 NPWT applications from 2009 to 2014. This series, comprised of 30 open fractures, 21 post-operative and 39 chronic wounds. The wound healing rate in our study was comparable to other published studies using NPWT. Conclusion: The addition of electronic timer switch will convert a suction apparatus into NPWT machine, and the results are equally effective compared to more expensive counter parts. The use of indigenous dressing materials reduces the cost significantly.

  4. Quantifying demand flexibility of power-to-heat and thermal energy storage in the control of building heating systems

    DEFF Research Database (Denmark)

    Finck, Christian; Li, Rongling; Kramer, Rick

    2018-01-01

    restricted by power-to-heat conversion such as heat pumps and thermal energy storage possibilities of a building. To quantify building demand flexibility, it is essential to capture the dynamic response of the building energy system with thermal energy storage. To identify the maximum flexibility a building......’s energy system can provide, optimal control is required. In this paper, optimal control serves to determine in detail demand flexibility of an office building equipped with heat pump, electric heater, and thermal energy storage tanks. The demand flexibility is quantified using different performance...... of TES and power-to-heat in any case of charging, discharging or idle mode. A simulation case study is performed showing that a water tank, a phase change material tank, and a thermochemical material tank integrated with building heating system can be designed to provide flexibility with optimal control....

  5. Increasing economic benefits by load-shifting of electrical heat pumps

    OpenAIRE

    Laveyne, Joannes; Zwaenepoel, Brecht; Van Eetvelde, Greet; Vandevelde, Lieven

    2014-01-01

    Electrical heating is still widely used in the process industry. While the use of immersion heaters for the production of hot water or steam is declining, the adoption rate of electrical heat pumps is increasing rapidly. Heat pumps show great flexibility and potential for energy savings, e.g. through low temperature waste heat recuperation. In combination with thermal storage they also allow for load shifting. Because their main power source is electricity, which up to now cannot be stored ef...

  6. Structural evaluation of W-211 flexible receiver platforms and tank pit walls

    International Nuclear Information System (INIS)

    Shrivastava, H.P.

    1997-01-01

    This document is a structural analysis of the Flexible Receiver Platforms and the tank-pit wall during removal of equipment and during a accidental drop of that equipment. The platform and the pit walls must withstand a accidental drop of a mixer and transfer pumps in specific pits in tanks 102-AP and 104-AP. A mixer pump will be removed from riser 11 in pit 2A on tank 241-AP-102. A transfer pump will be removed from riser 13 in pit 2D on tank 241-AP-102 and another transfer pump will be removed from riser 3A in pit 4A on tank 241-AP-104

  7. A Comparison of delO18 Composition of Water Extracted from Suction Lysimeters, Centrifugation, and Azeotropic Distillation

    Science.gov (United States)

    Figueroa, A.; Tindall, J. A.; Friedel, M. J.

    2005-12-01

    Concentration of delO18 in water samples extracted by suction lysimeters is compared to samples obtained by methods of centrifugation and azeotropic distillation. Intact soil cores (30 cm diameter by 40 cm height) were extracted from two different sites. Site 1 was rapid infiltration basin number 50, near Altamonte Springs in Seminole County, Florida on properties belonging to the Walt Disney World Resort Complex. Site 2 was the Missouri Management System Evaluation Area (MSEA) near Centralia in Boone County, Missouri. The delO18 water was analyzed on a mass spectrophotometer. Potassium Bromide (KBr) was also used as a tracer and analyzed by ion chromatography. A portion of the data obtained was modeled using CXTFIT. Water collected by centrifugation and azeotropic distillation data were about 2-5% more negative than that collected by suction lysimeter values from the Florida (sandy) soil and about 5-7 % more negative from the Missouri (well structured clay) soil. Results indicate that the majority of soil water in well structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. Also, it is plausible that evaporation caused some delO18 enrichment in the suction lysimeters. Suction lysimeters preferentially sampled water held at lower matric potentials, which may not represent total soil water. In cases where a sufficient volume of water has passed through the soil profile and displaced all previous pore water, suction lysimeters will however collect a representative sample of all the water at that depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeters be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The CXTFIT program worked well for Florida soils (a more homogeneous sand), but gave poor performance for Missouri soils (well structured clays) except for deeper depths where clay structure was less

  8. The Advanced Limiter Test-I (ALT-I) variable-geometry pump limiter module

    International Nuclear Information System (INIS)

    Pontau, A.E.; Malinowski, M.E.; Ver Berkmoes, A.A.; Guthrie, S.E.; Watson, R.D.; Goebel, D.M.; Campbell, G.A.

    1984-01-01

    The ALT-I variable geometry module has been designed to address many of the issues not previously settled by earlier experiments. The goal is to study the basic processes involved in pump limiter operation as well as demonstrate its utility and effect on the plasma. The flexibility and extensive instrumentation of ALT-I will offer a unique opportunity to parameterize operation and facilitate the engineering design of future pump limiters. (orig.)

  9. Small and low head pumped storage projects

    International Nuclear Information System (INIS)

    Makarechian, A.H.

    1991-01-01

    The purpose of this paper is to focus attention on small and low head pumped storage projects. These projects may be defined as having a capacity of less than 200-300 MW and down to about 20 MW, with heads of 1200 ft to about 300 ft or less. Many advantages of these smaller pumped storage projects include more flexibility in siting of a project, considerably shorter licensing and construction period, adaptability to closed system design concept to reduce adverse environmental impacts, considerably reduced risks of delays and substantial cost over-runs, better suited to meeting peaking capacity requirements for individual utilities, and much less transmission inter-connection requirements. An overall licensing and construction schedule of about 3 to 3 1/2 years is realistic for many smaller pumped storage projects, and competitive costs in terms of dollars per kW installed can be achieved

  10. Thopaz Portable Suction Systems in Thoracic Surgery: An end user assessment and feedback in a tertiary unit

    Directory of Open Access Journals (Sweden)

    Cantlin Teresa

    2011-04-01

    Full Text Available Abstract Background Thoracic surgical patients have chest drains inserted to enable re-expansion of lungs, to clear contents from the pleural cavity which sometimes require negative suction. Suction impedes mobility, may have variable suction delivery and increases risk of infection. Assessment of air-leak in conventional drains is not scientific and is subjective. Thopaz chest drain system is a portable suction unit which allows mobilization of the patient, with scientific digital flow recordings and an in built alarm system. Methods We evaluated the utility, staff and patient feedback of this device in a pilot evaluation in a regional thoracic unit in a structured format over a period of two months. Staff responses were graded on a scale of 1 to 6 [1 Excellent to 6 Poor]. Results 120 patients who underwent elective bullectomy/pleurectomy, VATS lung biopsies, VATS metastectomy and lung resections were evaluated. The staff feedback forms were positive. The staff liked the system as it was more scientific and accurately recordable. It made nursing and physiotherapy easier as they could mobilise patients early. The patients liked the compact design, weightlessness and the silence. It enabled mobilisation of the patients and scientific removal of chest drain. Conclusions Thopaz digital suction units were found to be user friendly and were liked by the staff and patients. The staff feedback stated the devices to be objective and scientific in making decisions about removal and enabled mobilisation.

  11. Microsatellite marker analysis of peach-potato aphids (Myzus persicae, Homoptera: Aphididae) from Scottish suction traps.

    Science.gov (United States)

    Malloch, G; Highet, F; Kasprowicz, L; Pickup, J; Neilson, R; Fenton, B

    2006-12-01

    The peach-potato aphid Myzus persicae (Sulzer) is an important vector of plant viruses. A network of suction traps collects aerial samples of this aphid in order to monitor and help predict its spatial distribution and likely impact on virus transmission in crops. A suction trap catch is thought to be a good representation of the total aphid pool. Sensitive molecular markers have been developed that determine the genetic composition of the M. persicae population. In Scotland, UK, these were applied to field collections revealing a limited number of clones. Molecular markers are less successful when applied to specimens that have been preserved in an ethanol-based trap fluid designed to preserve morphology. An assessment of different DNA extraction and PCR techniques is presented and the most efficient are used to analyse M. persicae specimens caught in the Dundee suction trap in 2001, a year when exceptionally high numbers were caught. The results reveal that the majority of the M. persicae caught belonged to two highly insecticide resistant clones. In addition, it was possible to compare the relative frequencies of genotypes caught in the trap with those collected at insecticide treated and untreated field sites in the vicinity. These results indicate that, in addition to suction trap data, the ability to sample field sites provides valuable early warning data which have implications for pest control and virus management strategies.

  12. Temperature measurement in WTE boilers using suction pyrometers.

    Science.gov (United States)

    Rinaldi, Fabio; Najafi, Behzad

    2013-11-15

    The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE) plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR) pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty.

  13. Temperature Measurement in WTE Boilers Using Suction Pyrometers

    Directory of Open Access Journals (Sweden)

    Fabio Rinaldi

    2013-11-01

    Full Text Available The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty.

  14. Blood loss associated with Ring uncemented total knee replacement: comparison between continuous and intermittent suction drainage.

    Science.gov (United States)

    Wittmann, F W; Ring, P A

    1984-01-01

    In a retrospective comparison of blood loss following uncemented total knee replacement, in which either continuous or intermittent suction drainage was used, measured blood loss was significantly greater with continuous drainage. However, a method of calculating actual blood loss demonstrated no significant difference. With intermittent drainage, more blood remains undetected around the knee joint; this technique should therefore be abandoned in favour of continuous suction drainage. PMID:6747978

  15. Effects of Alternate Leading Edge Cutback on the Space Shuttle Main Engine Low Pressure Fuel Pump

    Science.gov (United States)

    Mulder, Andrew; Skelley, Stephen

    2016-01-01

    A higher order cavitation oscillation observed in the SSME low pressure fuel pump has been eliminated in water flow testing of a modified subscale replica of the inducer. The low pressure pump was modified by removing the outboard sections of two opposing blades of the four-bladed inducer, blending the "cutback" regions into the blades at the leading edge and tip, and removing material on the suction sides to decrease the exposed leading edge thickness. The leading edge tips of the cutback blades were moved approximately 25 degrees from their previous locations, thereby increasing one blade to blade spacing, decreasing the second, while simultaneously moving the cutback tips downstream. The test was conducted in MSFC's inducer test loop at scaled operating conditions in degassed and filtered water. In addition to eliminating HOC across the entire scaled operating regime, rotating cavitation was suppressed while the range of both alternate blade and asymmetric cavitation were increased. These latter phenomena, and more significantly, the shifts between these cavitation modes also resulted in significant changes to the head coefficient at low cavitation numbers. Reverse flow was detected at a slightly larger flow coefficient with the cutback inducer and suction capability was reduced by approximately 1 velocity head at and above approximately 90% of the reference flow coefficient. These performance changes along with more intense reverse flow are consistent with poor flow area management and increased incidence in the cutback region. Although the test demonstrated that the inducer modification was successful at eliminating the higher order cavitation across the entire scaled operating regime, different, previously unobserved, cavitation oscillations were introduced and significant performance penalties were imposed.

  16. Hydrogenation study of suction-cast Ti{sub 40}Zr{sub 40}Ni{sub 20} quasicrystal

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Huogen; Li, Rong; Yin, Chen; Zheng, Shaotao; Zhang, Pengcheng [National Key Laboratory for Surface Physics and Chemistry, P.O. Box 718-35, Mian Yang 621907, Sichuan (China)

    2008-09-15

    Suction casting was predicted to be an usable method for improving the hydriding kinetics of Ti/Zr-based icosahedral quasicrystals (IQCs) in our previous work. To further determine it, a suction-cast Ti{sub 40}Zr{sub 40}Ni{sub 20} IQC alloy was used for hydrogenation studies by Pressure Composition Isotherm (PCI) and Temperature Programmed Desorption (TPD) techniques. The results showed that, this alloy absorbed hydrogen rapidly with obvious hydrogen pressure plateau and some reversibility, however, displayed very limited hydrogen capacity (about 0.7 wt.%) and low equilibrium pressure. After several hydrogenation/dehydrogenation cycles, the IQC structure transformed into two hydride phases, ZrH{sub 2-x} and one unknown, both of which decomposed at above 600 C, suggesting high thermo-stability for them. On the whole, indeed the suction-casting method can increase the hydrogen absorption rate of Ti/Zr-based IQCs, however, the hydrogenation properties of the Ti{sub 40}Zr{sub 40}Ni{sub 20} IQC alloy still need a mighty advancement. (author)

  17. Will long acting insulin analogs influence the use of insulin pump therapy in type 1 diabetes?

    NARCIS (Netherlands)

    DeVries, J. Hans

    2005-01-01

    Insulin pump therapy enjoys a steadily growing number of users and is associated with an approximately 0.5% lower A1c as compared to flexible insulin injection therapy in type 1 diabetes patients. An important question is whether superiority of insulin pump therapy persists in the era of rapid

  18. Defining a Ventilation Strategy for Flexible Bronchoscopy on Mechanically Ventilated Patients in the Medical Intensive Care Unit.

    Science.gov (United States)

    Greenstein, Yonatan Y; Shakespeare, Eric; Doelken, Peter; Mayo, Paul H

    2017-07-01

    Flexible bronchoscopy (FB) in intubated patients on mechanical ventilation increases airway resistance. During FB, two ventilatory strategies are possible: maintaining tidal volume (VT) while maintaining baseline CO2 or allowing reduction of VT. The former strategy carries risk of hyperinflation due to expiratory flow limitation with FB. The aim of the authors was too study end expiratory lung volume (EELV) during FB of intubated subjects while limiting VT. We studied 16 subjects who were intubated on mechanical ventilation and required FB. Changes in EELV were measured by respiratory inductance plethysmography. Ventilator mechanics, EELV, and arterial blood gases, were measured. FB insertions decreased EELV in 64% of cases (-325±371 mL) and increased it in 32% of cases (65±59 mL). Suctioning decreased EELV in 76% of cases (-120±104 mL) and increased it in 16% of cases (29±33 mL). Respiratory mechanics were unchanged. Pre-FB and post-FB, PaO2 decreased by 61±96 mm Hg and PaCO2 increased by 15±7 mm Hg. There was no clinically significant increase in EELV in any subject during FB. Decreases in EELV coincided with FB-suctioning maneuvers. Peak pressure limiting ventilation protected the subject against hyperinflation with a consequent, well-tolerated reduction in VT, and hypercapnea. Suctioning should be limited, especially in patients vulnerable to derecruitment effect.

  19. Silent cooling system with a double suction type centrifugal fan with backward blades; Ryosuikomi turbo fan wo mochiita teisoon engine reikyaku system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Funabashi, S. [Hitachi, Ltd., Tokyo (Japan); Nakamura, K. [Hitachi Construction Machinery Co. Ltd., Tokyo (Japan)

    2000-04-25

    We have developed a new cooling system for the engine of construction machinery. This system produces two different air flow routes by a double suction type centrifugal fan with backward blades. We first measured aerodynamic performance and sound level of the double suction type fan, which consists of two single suction type fans of different design, and compared these measurements to those of single suction type fans. Next, we installed the fan in a scale model of the new cooling system. The performance of this double suction type fan was different to that of a single suction type. It is considered that the effect of interaction of the exit flows from the two different fans caused this performance change. The test model installed in an engine compartment showed that this cooling system reduced the area of air inlets and outlets around the engine and did not cause re-circulation of cooling air. (author)

  20. Heat-transfer and pressure distributions for laminar separated flows downstream of rearward-facing steps with and without mass suction

    Science.gov (United States)

    Brown, R. D.; Jakubowski, A. K.

    1974-01-01

    Heat-transfer and pressure distributions were measured for laminar separated flows downstream of rearward-facing steps with and without mass suction. The flow conditions were such that the boundary-layer thickness was comparable to or larger than the step height. For both suction and no-suction cases, an increase in the step height resulted in a sharp decrease in the initial heat-transfer rates behind the step. Downstream, however, the heat transfer gradually recovered back to less than or near attached-flow values. Mass suction from the step base area increased the local heat-transfer rates; however, this effect was relatively weak for the laminar flows considered. Even removal of the entire approaching boundary layer raised the post-step heat-transfer rates only about 10 percent above the flatplate values. Post-step pressure distributions were found to depend on the entrainment conditions at separation. In the case of the solid-faced step, a sharp pressure drop behind the step was followed by a very short plateau and relatively fast recompression. For the slotted-step connected to a large plenum but without suction, the pressure drop at the base was much smaller and the downstream recompression more gradual than that for solid-faced step.

  1. Flexible Organic Electronics in Biology: Materials and Devices.

    Science.gov (United States)

    Liao, Caizhi; Zhang, Meng; Yao, Mei Yu; Hua, Tao; Li, Li; Yan, Feng

    2015-12-09

    At the convergence of organic electronics and biology, organic bioelectronics attracts great scientific interest. The potential applications of organic semiconductors to reversibly transmit biological signals or stimulate biological tissues inspires many research groups to explore the use of organic electronics in biological systems. Considering the surfaces of movable living tissues being arbitrarily curved at physiological environments, the flexibility of organic bioelectronic devices is of paramount importance in enabling stable and reliable performances by improving the contact and interaction of the devices with biological systems. Significant advances in flexible organic bio-electronics have been achieved in the areas of flexible organic thin film transistors (OTFTs), polymer electrodes, smart textiles, organic electrochemical ion pumps (OEIPs), ion bipolar junction transistors (IBJTs) and chemiresistors. This review will firstly discuss the materials used in flexible organic bioelectronics, which is followed by an overview on various types of flexible organic bioelectronic devices. The versatility of flexible organic bioelectronics promises a bright future for this emerging area. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Flexible receiver adapter and secondary bagger support frame analysis for 241AP102 mixer pump removal

    International Nuclear Information System (INIS)

    Axup, M.D.; Egger, J.

    1995-01-01

    As part of the Grout Process startup, the 241AP102 Mixer Pump, failed in 1993, is scheduled to be removed. A structural analysis was performed on two components to be used in the bagging process for the failed pump. The loading criteria was based on a worst case accident of the entire pump weight (including a 50% impact load) being applied over a small localized area. The results show that the design of each structure is adequate to protect against failure, i.e., yield

  3. CFD simulation of flow through single and multi vane spiral pump for low pressure application using moving node unsteady computation

    International Nuclear Information System (INIS)

    Banerjee, I.; Mahendra, A.K.; Chandresh, B.G.; Srikanthan, M.R.; Bera, T.K.

    2010-01-01

    A spiral pump uses two interleaved spirals (it can be involutes of a circle, involutes of a square, hybrid wraps, Archimedean spiral, logarithmic spirals and so on). Interleaved spiral orbits eccentrically without rotation around a fixed scroll, thereby trapping and compressing pockets of fluids between the spirals. Another method of providing the compression motion is by virtue of co-rotating the spirals synchronously with an offset in centers of rotation thereby providing relative motion similar to orbiting. Recently spiral pumps for low-pressure application have become popular. Since spiral pumps contain gas volumes, whose shapes and size change continuously, the flow fields inside the pumps is time dependent. The unsteadiness controls the mechanisms responsible for the behavior of the spiral pump components. To improve the spiral pump design for better performance as per our process requirement and reliability, information is required to understand the detailed physics of the unsteady flows inside the spiral pumps. The unsteady flows in a pump are studied numerically. The system simulated includes one side gap between fixed and moving spirals as the other side lies just in the reverse symmetry of the one side. Heavy molecular weight, condensable gas is used as the moving fluid. The mesh free Least Square Kinetic Upwind Method (LSKUM) for moving node is applied for numerical analysis of wobbling spiral. Nodes and boundaries change their positions, for every real time step hence at every iteration nodes take new coordinates. Our work consists of identifying various spiral dimensions and geometry, geometric modeling of suction process, identifying the eccentric orbiting motion of the moving spiral, formation of variable velocity moving nodes. Flow analysis of the spiral pump is done with a view to design and develop new pump as per our requirement. Experimental data from an existing spiral pump is used to carryout validation of the code. (author)

  4. Active technique by suction to control the flow structure over a van model

    Science.gov (United States)

    Harinaldi, Budiarso, Warjito, Kosasih, Engkos A.; Tarakka, Rustan; Simanungkalit, Sabar P.

    2012-06-01

    Today research trend in car aerodynamics are carried out from the point of view of the durable development. Some car companies have the objective to develop control solution that enable to reduce the aerodynamic drag of vehicle. It provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled with a modified form of Ahmed's body by changing the orientation of the flow from its original form (modified/reversed Ahmed Body). This model is equipped with a suction on the rear side to comprehensively examine the pressure field modifications that occur. The investigation combines computational and experimental work. The computational simulation used is k-epsilon flow turbulence model. The reversed Ahmed body used in the investigation has slant angle (φ) 35° at the front part. In the computational work, meshing type is tetra/hybrid element with hex core type and the grid number is more than 1.7 million in order to ensure detail discretization and more accurate calculation results. The boundary condition is upstream velocity of 11.1 m/s. Mean free stream at far upstream region is assumed in a steady state condition and uniform. The suction velocity is set at 1 m/s. Meanwhile in the experimental work a reversed Ahmed model is tested in a controlled wind tunnel experiments. The main measurement is the drag aerodynamic measurement at rear of the body of the model using strain gage. The results show that the application of a suction in the rear part of the van model give the effect of reducing the wake and the vortex is formed. Aerodynamic drag reduction close to 24% for the computational approach and 14.8% for the experimental approach by introducing a suction have been obtained.

  5. Vortical and acoustical mode coupling inside a porous tube with uniform wall suction.

    Science.gov (United States)

    Jankowskia, T A; Majdalani, J

    2005-06-01

    This paper considers the oscillatory motion of gases inside a long porous tube of the closed-open type. In particular, the focus is placed on describing an analytical solution for the internal acoustico-vortical coupling that arises in the presence of appreciable wall suction. This unsteady field is driven by longitudinal oscillatory waves that are triggered by small unavoidable fluctuations in the wall suction speed. Under the assumption of small amplitude oscillations, the time-dependent governing equations are linearized through a regular perturbation of the dependent variables. Further application of the Helmholtz vector decomposition theorem enables us to discriminate between acoustical and vortical equations. After solving the wave equation for the acoustical contribution, the boundary-driven vortical field is considered. The method of matched-asymptotic expansions is then used to obtain a closed-form solution for the unsteady momentum equation developing from flow decomposition. An exact series expansion is also derived and shown to coincide with the numerical solution for the problem. The numerically verified end results suggest that the asymptotic scheme is capable of providing a sufficiently accurate solution. This is due to the error associated with the matched-asymptotic expansion being smaller than the error introduced in the Navier-Stokes linearization. A basis for comparison is established by examining the evolution of the oscillatory field in both space and time. The corresponding boundary-layer behavior is also characterized over a range of oscillation frequencies and wall suction velocities. In general, the current solution is found to exhibit features that are consistent with the laminar theory of periodic flows. By comparison to the Sexl profile in nonporous tubes, the critically damped solution obtained here exhibits a slightly smaller overshoot and depth of penetration. These features may be attributed to the suction effect that tends to

  6. Sodium pumping: pump problems

    International Nuclear Information System (INIS)

    Guer, M.; Guiton, P.

    Information on sodium pumps for LMFBR type reactors is presented concerning ring pump design, pool reactor pump design, secondary pumps, sodium bearings, swivel joints of the oscillating annulus, and thermal shock loads

  7. Suction blister lesions and epithelialization monitored by optical coherence tomography

    DEFF Research Database (Denmark)

    Ahlström, M G; Gjerdrum, L M R; Larsen, H F

    2018-01-01

    suction blister was raised on each buttock, and the blister roof was excised. Lesions were covered with moisture-retaining dressing. In Study 1, the lesions were OCT-scanned on day 0 (D0), D2 and D4 and excised for histological examination. In Study 2, the progress of epithelialization and skin barrier...

  8. Closed suction drainage using Lichtenstein technique in preventing wound complications following inguinal hernioplasty: brief report

    Directory of Open Access Journals (Sweden)

    Hamid Reza Hemmati

    2015-03-01

    Results: No adverse event including hematoma, seroma or wound infection occurred in either group with or without closed suction drainage in the first 10 days after surgery. Only one patient carried wound infection during days 10 to 15 following operation who was in the group with closed drainage (P=1.00. Conclusion: In this study, Seroma and hematoma was not observed in patients with and without closed suction drainage. To avoid drains' complications, indiscriminate use of antibiotics, prolonged hospital stay, we do not recommend the use of drains in this type of surgery.

  9. Research and application of key technology of electric submersible plunger pump

    Science.gov (United States)

    Qian, K.; Sun, Y. N.; Zheng, S.; Du, W. S.; Li, J. N.; Pei, G. Z.; Gao, Y.; Wu, N.

    2018-06-01

    Electric submersible plunger pump is a new generation of rodless oil production equipment, whose improvements and upgrades of key technologies are conducive to its large-scale application and reduce the cost and improve the efficiency. In this paper, the operating mechanism of the unit in-depth study, aimed at the problems existing in oilfield production, to propose an optimization method creatively, including the optimal design of a linear motor for submersible oil, development of new double-acting load-relief pump, embedded flexible closed-loop control technology, research and development of low-cost power cables. 90 oil wells were used on field application, the average pump inspection cycle is 608 days, the longest pump check cycle has exceeded 1037 days, the average power saving rate is 45.6%. Application results show that the new technology of optimization and upgrading can further improve the reliability and adaptability of electric submersible plunger pump, reduce the cost of investment.

  10. Systematic review and meta-analysis of closed suction drainage versus non-drainage in primary hip arthroplasty.

    LENUS (Irish Health Repository)

    Kelly, Enda G

    2014-03-01

    The routine use of drains in surgery has been dogmatically instituted in some disciplines. Orthopaedic surgery is one such sub-speciality. The use of postoperative closed suction drainage in total hip arthroplasty (THA) has become increasingly controversial with multiple randomised control trials performed to assess the benefit to outcome in THA. The hypothesis of this systematic review is that closed suction drainage does not infer a benefit and increase transfusion requirements of primary total hip arthroplasty patients. A systematic review and meta-analysis was conducted adhering to the PRISMA guidelines. A search of the available literature was performed on PubMed, Cochrane Central Registry of Controlled Trials, MEDLINE (OVID) and EMBASE using a combination of MeSH terms and Boolean operators. All data analysis was performed using the Cochrane Collaboration\\'s Review Manager 5.1. Sixteen studies (n=2705) were included in the analysis. Post-operative closed suction drainage was found to increase total blood loss and blood transfusion requirements (p<0.05). Surgical site infection demonstrated no significant difference between the two groups (p=0.82). No significant difference in haematoma formation between groups (p=0.19) was elicited. The routine use of closed suction drainage systems post primary hip arthroplasty is not supported by this meta-analysis. However, the heterogeneity between studies does limit the accuracy of the meta-analysis.

  11. Numerical investigation of solid-liquid two phase flow in a non-clogging centrifugal pump at off-design conditions

    International Nuclear Information System (INIS)

    Zhao, B J; Chen, H L; Hou, D H; Huang, Z F

    2012-01-01

    The solid-liquid two-phase flow fields in the non-clogging centrifugal pump with a double-channel impeller have been investigated numerically for the design condition and also off-design conditions, in order to study the solid-liquid two-phase flow pattern and non-clogging mechanism in non-clogging centrifugal pumps. The main conclusions include: The sand volume fraction distribution is extremely inhomogeneous in the whole flow channel of the pump at off-design conditions. In the impeller, particles mainly flow along the pressure surface and hub; In the volute, particles mainly accumulate in the region near to the exit of volute, the largest sand volume fraction is observed at the tongue, and a large number of particles collide with volute wall and exit the volute after circling around the volute for several times. When the particle diameter increases, particles tend to accumulate on the pressure side of the impeller, and more particles crash with the pressure side of the blade. And larger sand volume fraction gratitude is also observed in the whole flow channel of the pump. With the decrease of the inlet sand volume fraction, particles tend to accumulate on the suction side of the blade. Compared with the particle diameter, the inlet sand volume fraction has less influence on the sand volume fraction gratitude in the whole channel of the pump. At the large flow rate, the minimum and maximum sand volume fraction in the whole flow channel of the model pump tends to be smaller than that at the small flow rate. Thus, it is concluded that the water transportation capacity increases with the flow rate. This research will strengthen people's understanding of the multiphase flow pattern in non-clogging centrifugal pumps, thus provides a theoretical basis for the optimal design of non-clogging centrifugal pumps.

  12. [Pain assessment of tracheal suctioning on brain injury patients by pain behavioral indicator scale (ESCID)].

    Science.gov (United States)

    López-López, C; Murillo-Pérez, M A; Morales-Sánchez, C; Torrente-Vela, S; Orejana-Martín, M; García-Iglesias, M; Cuenca-Solanas, M; Alted-López, E

    2014-01-01

    To assess pain response on patients with moderate to severe head injury before a common nursing procedure: tracheal suctioning. An observational longitudinal pilot study with consecutive sampling performed from September to December of 2012. Pain was assessed by a pain behavioral indicator scale 5 minutes before, meanwhile and 15 minutes after tracheal suctioning the days 1, 3 and 6 of their intensive care unit (ICU) stay, as well as a non-painful procedure: rubbing with gauze the forearm of the patient. Pseudo-analgesia and hemodynamic variables were also recorded. Descriptive analysis of the variables, inferential statistics with t-student and Anova with SPSS 17.0; statistical tests were considered significant if the critical level observed was less than 5% (P.05) were shown. Data for the painless procedure were significantly different on day 6 (P<.05) CONCLUSION: During tracheal suctioning in patients with head injury in the first 6 days in the ICU, objective mild-moderate pain according to ESCID scale has been detected. Copyright © 2013 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  13. Estimation of probability density functions of damage parameter for valve leakage detection in reciprocating pump used in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Kyeom; Kim, Tae Yun; Kim, Hyun Su; Chai, Jang Bom; Lee, Jin Woo [Div. of Mechanical Engineering, Ajou University, Suwon (Korea, Republic of)

    2016-10-15

    This paper presents an advanced estimation method for obtaining the probability density functions of a damage parameter for valve leakage detection in a reciprocating pump. The estimation method is based on a comparison of model data which are simulated by using a mathematical model, and experimental data which are measured on the inside and outside of the reciprocating pump in operation. The mathematical model, which is simplified and extended on the basis of previous models, describes not only the normal state of the pump, but also its abnormal state caused by valve leakage. The pressure in the cylinder is expressed as a function of the crankshaft angle, and an additional volume flow rate due to the valve leakage is quantified by a damage parameter in the mathematical model. The change in the cylinder pressure profiles due to the suction valve leakage is noticeable in the compression and expansion modes of the pump. The damage parameter value over 300 cycles is calculated in two ways, considering advance or delay in the opening and closing angles of the discharge valves. The probability density functions of the damage parameter are compared for diagnosis and prognosis on the basis of the probabilistic features of valve leakage.

  14. Estimation of probability density functions of damage parameter for valve leakage detection in reciprocating pump used in nuclear power plants

    International Nuclear Information System (INIS)

    Lee, Jong Kyeom; Kim, Tae Yun; Kim, Hyun Su; Chai, Jang Bom; Lee, Jin Woo

    2016-01-01

    This paper presents an advanced estimation method for obtaining the probability density functions of a damage parameter for valve leakage detection in a reciprocating pump. The estimation method is based on a comparison of model data which are simulated by using a mathematical model, and experimental data which are measured on the inside and outside of the reciprocating pump in operation. The mathematical model, which is simplified and extended on the basis of previous models, describes not only the normal state of the pump, but also its abnormal state caused by valve leakage. The pressure in the cylinder is expressed as a function of the crankshaft angle, and an additional volume flow rate due to the valve leakage is quantified by a damage parameter in the mathematical model. The change in the cylinder pressure profiles due to the suction valve leakage is noticeable in the compression and expansion modes of the pump. The damage parameter value over 300 cycles is calculated in two ways, considering advance or delay in the opening and closing angles of the discharge valves. The probability density functions of the damage parameter are compared for diagnosis and prognosis on the basis of the probabilistic features of valve leakage

  15. Estimation of Probability Density Functions of Damage Parameter for Valve Leakage Detection in Reciprocating Pump Used in Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    Jong Kyeom Lee

    2016-10-01

    Full Text Available This paper presents an advanced estimation method for obtaining the probability density functions of a damage parameter for valve leakage detection in a reciprocating pump. The estimation method is based on a comparison of model data which are simulated by using a mathematical model, and experimental data which are measured on the inside and outside of the reciprocating pump in operation. The mathematical model, which is simplified and extended on the basis of previous models, describes not only the normal state of the pump, but also its abnormal state caused by valve leakage. The pressure in the cylinder is expressed as a function of the crankshaft angle, and an additional volume flow rate due to the valve leakage is quantified by a damage parameter in the mathematical model. The change in the cylinder pressure profiles due to the suction valve leakage is noticeable in the compression and expansion modes of the pump. The damage parameter value over 300 cycles is calculated in two ways, considering advance or delay in the opening and closing angles of the discharge valves. The probability density functions of the damage parameter are compared for diagnosis and prognosis on the basis of the probabilistic features of valve leakage.

  16. The radontechnical process of the sub-slab suction system in detached, semi-detached and terraced houses; Imupistejaerjestelmaen radontekninen toiminta eri tyyppisissae pien- ja rivitaloissa

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, A.V.; Rissanen, R.; Viljanen, M. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Structural Engineering and Building Physics; Arvela, H. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

    1997-12-31

    The sub-slab suction system is a repair method for decreasing radon transfer from soil to indoor air in houses. The sub-slab suction system changes the flow field with the aim to reduce the radon content under the ground slab or/and changes the flow direction from indoor air to foundation soil. The study is divided into the theoretical and experimental part. The theoretical part concentrates on solving the factors affecting the sub-slab suction system taking into consideration features of old houses. The experimental part uses the results of the theoretical part when the level and the type of the suction point had been chosen. The effect of the sub-slab suction system was tested with pressure difference experiments and the radon content measurements in 26 different, typical Finnish detached, semi-detached and terrace houses.

  17. Suction/inspiration against resistance or standardized Mueller maneuver: a new breathing technique to improve contrast density within the pulmonary artery: a pilot CT study

    Energy Technology Data Exchange (ETDEWEB)

    Gutzeit, Andreas [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland); Kantonsspital Winterthur, Department of Radiology, Winterthur (Switzerland); Froehlich, Johannes M.; Weymarn, Constantin von; Goyen, Matthias [Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland); Waelti, Stephan [Cantonal Hospital St. Gallen, Department of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Roos, Justus E. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Meissnitzer, Matthias; Hergan, Klaus [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Czell, David [Cantonal Hospital Winterthur, Department of Neurology, Winterthur (Switzerland); Reischauer, Carolin [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland)

    2015-11-15

    Our aim was to prospectively investigate whether the recently introduced suction/inspiration against resistance breathing method leads to higher computed tomography (CT) contrast density in the pulmonary artery compared to standard breathing. The present study was approved by the Medical Ethics committee and all subjects gave written informed consent. Fifteen patients, each without suspicious lung emboli, were randomly assigned to four different groups with different breathing maneuvers (suction against resistance, Valsalva, inspiration, expiration) during routine CT. Contrast enhancement in the central and peripheral sections of the pulmonary artery were measured and compared with one another. Peripheral enhancement during suction yielded increased mean densities of 138.14 Hounsfield units (HU) (p = 0.001), compared to Valsalva and a mean density of 67.97 HU superior to inspiration (p = 0.075). Finally, suction in comparison to expiration resulted in a mean increase of 30.51 HU (p = 0.42). Central parts of pulmonary arteries presented significantly increased enhancement values (95.74 HU) for suction versus the Valsalva technique (p = 0.020), while all other mean densities were in favour of suction (versus inspiration: p = 0.201; versus expiration: p = 0.790) without reaching significance. Suction/Inspiration against resistance is a promising technique to improve contrast density within pulmonary vessels, especially in the peripheral parts, in comparison to other breathing maneuvers. (orig.)

  18. Pumped energy transfer stations (STEP)

    International Nuclear Information System (INIS)

    Tournery, Jean-Francois

    2015-12-01

    As objectives of development are high for renewable energies (they are supposed to cover 50 per cent of new energy needs by 2035), pumped energy transfer stations are to play an important role in this respect. The author first discusses the consequences of the development of renewable energies on the exploitation of electric grids: issue of intermittency for some of them, envisaged solutions. Then, he addresses one of the solutions: the storage of electric power. He notices that increasing the potential energy of a volume of water is presently the most mature solution to face massive needs of the power system. Dams and pumped energy transfer stations represent now almost the whole installed storage power in the world. The author then presents these pumped energy transfer stations: principle, brief history (the first appeared in Italy and Switzerland at the end of the 1890's). He indicates the various parameters of assessment of such stations: maximum stored energy, installed power in pumping mode and turbine mode, time constant, efficiency, level of flexibility. He discusses economic issues. He describes and comments the operation of turbine-pump groups: ternary groups, reversible binary groups. He discusses barriers to be overcome and technical advances to be made for varying speed groups and for marine stations. He finally gives an overview (table with number of stations belonging to different power ranges, remarkable installations) of existing stations in China, USA, Japan, Germany, Austria, Spain, Portugal, Italy, Switzerland, France and UK, and indicate predictions regarding storage needs at the world level. Some data are finally indicated for the six existing French installations

  19. Air suctioning during colon biopsy forceps removal reduces bacterial air contamination in the endoscopy suite.

    Science.gov (United States)

    Vavricka, S R; Tutuian, R; Imhof, A; Wildi, S; Gubler, C; Fruehauf, H; Ruef, C; Schoepfer, A M; Fried, M

    2010-09-01

    Bacterial contamination of endoscopy suites is of concern; however studies evaluating bacterial aerosols are lacking. We aimed to determine the effectiveness of air suctioning during removal of biopsy forceps in reducing bacterial air contamination. This was a prospective single-blinded trial involving 50 patients who were undergoing elective nontherapeutic colonoscopy. During colonoscopy, endoscopists removed the biopsy forceps first without and then with suctioning following contact with the sigmoid mucosa. A total of 50 L of air was collected continuously for 30 seconds at 30-cm distance from the biopsy channel valve of the colonoscope, with time starting at forceps removal. Airborne bacteria were collected by an impactor air sampler (MAS-100). Standard Petri dishes with CNA blood agar were used to culture Gram-positive bacteria. Main outcome measure was the bacterial load in endoscopy room air. At the beginning and end of the daily colonoscopy program, the median (and interquartile [IQR] range) bioaerosol burden was 4 colony forming units (CFU)/m (3) (IQR 3 - 6) and 16 CFU/m (3) (IQR 13 - 18), respectively. Air suctioning during removal of the biopsy forceps reduced the bioaerosol burden from a median of 14 CFU/m (3) (IQR 11 - 29) to a median of 7 CFU/m (3) (IQR 4 - 16) ( P = 0.0001). Predominantly enterococci were identified on the agar plates. The bacterial aerosol burden during handling of biopsy forceps can be reduced by applying air suction while removing the forceps. This simple method may reduce transmission of infectious agents during gastrointestinal endoscopies. Copyright Georg Thieme Verlag KG Stuttgart . New York.

  20. Dynamic stress of impeller blade of shaft extension tubular pump device based on bidirectional fluid-structure interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kan, Kan; Liu, Huiwen; Yang, Chunxia [Hohai University, Nanjing (China); Zheng, Yuan [National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Nanjing (China); Fu, Shifeng; Zhang, Xin [Power China Huadong Engineering Corporation, Hangzhou (China)

    2017-04-15

    Current research on the stability of tubular pumps is mainly concerned with the transient hydrodynamic characteristics. However, the structural response under the influence of fluid-structure interaction hasn't been taken fully into consideration. The instability of the structure can cause vibration and cracks, which may threaten the safety of the unit. We used bidirectional fluid-structure interaction to comprehensively analyze the dynamic stress characteristics of the impeller blades of the shaft extension tubular pump device. Furthermore, dynamic stress of impeller blade of shaft extension tubular pump device was solved under different lift conditions of 0° blade angle. Based on Reynolds-average N-S equation and SST k-ω turbulence model, numerical simulation was carried out for three-dimensional unsteady incompressible turbulent flow field of the pump device whole flow passage. Meanwhile, the finite element method was used to calculate dynamic characteristics of the blade structure. The blade dynamic stress distribution was obtained on the basis of fourth strength theory. The research results indicate that the maximum blade dynamic stress appears at the joint between root of inlet side of the blade suction surface and the axis. Considering the influence of gravity, the fluctuation of the blade dynamic stress increases initially and decreases afterwards within a rotation period. In the meantime, the dynamic stress in the middle part of inlet edge presents larger relative fluctuation amplitude. Finally, a prediction method for dynamic stress distribution of tubular pump considering fluid-structure interaction and gravity effect was proposed. This method can be used in the design stage of tubular pump to predict dynamic stress distribution of the structure under different operating conditions, improve the reliability of pump impeller and analyze the impeller fatigue life.

  1. Laboratory determined suction potential of Topopah Spring tuff at high temperatures

    International Nuclear Information System (INIS)

    Daily, W.; Lin, Wunan.

    1991-01-01

    The purpose of this work is to experimentally determine the capillary suction potential of Topopah Spring tuff from Yucca Mountain, Nye County, Nevada. This data can be used to help characterize the unsaturated hydraulic properties of the densely welded tuff at this site. 7 refs., 4 figs., 1 tab

  2. Instruction Workbook for Tracheostomy Suctioning and Misting in a School Setting.

    Science.gov (United States)

    Wolf, Karen McKinney; Roach, Antionette Andolfatto

    The handbook presents California guidelines for training school personnel to provide skilled nursing procedures such as tracheostomy suctioning and misting for students with special health needs. The workbook begins with an overview of the anatomy and function of the respiratory system, specifically breathing mechanics. Part 2 considers the…

  3. Experimental Study on Compression/Absorption High-Temperature Hybrid Heat Pump with Natural Refrigerant Mixture

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Young; Park, Seong Ryong; Baik, Young Jin; Chang, Ki Chang; Ra, Ho Sang; Kim, Min Sung [Korea Institute of Energy Research, Daejeon (Korea, Republic of); Kim, Yong Chan [Korea University, Seoul (Korea, Republic of)

    2011-12-15

    This research concerns the development of a compression/absorption high-temperature hybrid heat pump that uses a natural refrigerant mixture. Heat pumps based on the compression/absorption cycle offer various advantages over conventional heat pumps based on the vapor compression cycle, such as large temperature glide, temperature lift, flexible operating range, and capacity control. In this study, a lab-scale prototype hybrid heat pump was constructed with a two-stage compressor, absorber, desorber, desuperheater, solution heat exchanger, solution pump, liquid/vapor separator, and rectifier as the main components. The hybrid heat pump system operated at 10-kW-class heating capacity producing hot water whose temperature was more than 90 .deg. C when the heat source and sink temperatures were 50 .deg. C. Experiments with various NH{sub 3}/H{sub 2}O mass fractions and compressor/pump circulation ratios were performed on the system. From the study, the system performance was optimized at a specific NH{sub 3} concentration.

  4. Flexible nanovectors

    International Nuclear Information System (INIS)

    Pugno, Nicola M

    2008-01-01

    In this paper we show that the control of adhesion in highly flexible (a property that could be crucial for smart drug delivery but which is still ignored in the literature) nanovectors can help in smartly targeting and delivering the drug. The existence of and the conditions for activating and controlling a super-adhesive state are addressed. Even if such a state has never been observed in nanovectors, our calculations, as well as observations in spiders and geckos, suggest its existence and feasible control. Control of the competition between the drag and the adhesive force is exploited to improve the targeting ability and a hierarchical model is applied to describe a real vasculature. The high flexibility of the nanovector is used to smartly deliver the drug only during adhesion by nanopumping or, as a limiting case, by the new concept of 'adhesion induced nanovector implosion'; a liquid drop analogy is utilized for the calculations. Fast (pumping) and slow (diffusion) drug deliveries can thus be separately controlled by controlling the size and shape of the nanovector. Multiple stage nanovectors are also briefly discussed, mimicking aerospace vector strategies.

  5. Flexible nanovectors

    Science.gov (United States)

    Pugno, Nicola M.

    2008-11-01

    In this paper we show that the control of adhesion in highly flexible (a property that could be crucial for smart drug delivery but which is still ignored in the literature) nanovectors can help in smartly targeting and delivering the drug. The existence of and the conditions for activating and controlling a super-adhesive state are addressed. Even if such a state has never been observed in nanovectors, our calculations, as well as observations in spiders and geckos, suggest its existence and feasible control. Control of the competition between the drag and the adhesive force is exploited to improve the targeting ability and a hierarchical model is applied to describe a real vasculature. The high flexibility of the nanovector is used to smartly deliver the drug only during adhesion by nanopumping or, as a limiting case, by the new concept of 'adhesion induced nanovector implosion'; a liquid drop analogy is utilized for the calculations. Fast (pumping) and slow (diffusion) drug deliveries can thus be separately controlled by controlling the size and shape of the nanovector. Multiple stage nanovectors are also briefly discussed, mimicking aerospace vector strategies.

  6. A wet-tolerant adhesive patch inspired by protuberances in suction cups of octopi

    Science.gov (United States)

    Baik, Sangyul; Kim, Da Wan; Park, Youngjin; Lee, Tae-Jin; Ho Bhang, Suk; Pang, Changhyun

    2017-06-01

    Adhesion strategies that rely on mechanical interlocking or molecular attractions between surfaces can suffer when coming into contact with liquids. Thus far, artificial wet and dry adhesives have included hierarchical mushroom-shaped or porous structures that allow suction or capillarity, supramolecular structures comprising nanoparticles, and chemistry-based attractants that use various protein polyelectrolytes. However, it is challenging to develop adhesives that are simple to make and also perform well—and repeatedly—under both wet and dry conditions, while avoiding non-chemical contamination on the adhered surfaces. Here we present an artificial, biologically inspired, reversible wet/dry adhesion system that is based on the dome-like protuberances found in the suction cups of octopi. To mimic the architecture of these protuberances, we use a simple, solution-based, air-trap technique that involves fabricating a patterned structure as a polymeric master, and using it to produce a reversed architecture, without any sophisticated chemical syntheses or surface modifications. The micrometre-scale domes in our artificial adhesive enhance the suction stress. This octopus-inspired system exhibits strong, reversible, highly repeatable adhesion to silicon wafers, glass, and rough skin surfaces under various conditions (dry, moist, under water and under oil). To demonstrate a potential application, we also used our adhesive to transport a large silicon wafer in air and under water without any resulting surface contamination.

  7. Modular pump limiter systems for large tokamaks

    International Nuclear Information System (INIS)

    Uckan, T.; Klepper, C.C.; Mioduszewski, P.K.; McGrath, R.T.

    1987-09-01

    Long-pulse (>10-s) operation of large tokamaks with high-power (>10-MW) heating and extensive external fueling will require correspondingly efficient particle exhaust for density control. A pump limiter can provide the needed exhaust capability by removing a small percentage of the particles, which would otherwise be recycled. Single pump limiter modules have been operated successfully on ISX-B, PDX, TEXTOR, and PLT. An axisymmetric pump limiter is now being installed and will be studied in TEXTOR. A third type of pump limiter is a system that consists of several modules and exhibits performance different from that of a single module. To take advantage of the flexibility of a modular pump limiter system in a high-power, long-pulse device, the power load must be distributed among a number of modules. Because each added module changes the performance of all the others, a set of design criteria must be defined for the overall limiter system. The design parameters for the modules are then determined from the system requirements for particle and power removal. Design criteria and parameters are presented, and the impact on module design of the state of the art in engineering technology is discussed. The relationship between modules are considered from the standpoint of flux coverage and shadowing effects. The results are applied to the Tore Supra tokamak. A preliminary conceptual design for the Tore Supra pump limiter system is discussed, and the design parameters of the limiter modules are presented. 21 refs., 12 figs

  8. Abdominal drainage following cholecystectomy: high, low, or no suction?

    OpenAIRE

    McCormack, T. T.; Abel, P. D.; Collins, C. D.

    1983-01-01

    A prospective trial to assess the effect of suction in an abdominal drain following cholecystectomy was carried out. Three types of closed drainage system were compared: a simple tube drain, a low negative pressure drain, and a high negative pressure drain: 120 consecutive patients undergoing cholecystectomy were randomly allocated to one of the three drainage groups. There was no significant difference in postoperative pyrexia, wound infection, chest infection, or hospital stay. This study f...

  9. Successful energy transition in Germany by pumped storage expansion; Energiewende erfolgreich gestalten durch Pumpspeicherausbau

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Klaus [Voith Hydro Holding GmbH und Co. KG, Heidenheim (Germany). FuE; Rotering, Niklas [RWTH Aachen Univ. (Germany). Forschungsgruppe Versorgungsqualitaet und Regulierung

    2014-11-01

    Operational flexibility in electrical energy generation and consumption as well as the provision of reliable and available capacity are two major challenges of the German energy transition ('Energiewende'). The consistent deployment of cost-effective and proven pumped storage technology can provide significant contributions to meet both challenges. This paper shows that an expansion of pumped storage plants as part of the energy transition is a technically and macro-economically interesting option for Germany. Pumped storage plants compensate the volatility of renewables and enable gentle and economically efficient operation of the remaining thermal power plant fleet.

  10. Study on conservation of light diesel oil and electricity used in pump-sets for lift irrigation in Gujarat State

    Energy Technology Data Exchange (ETDEWEB)

    Patel, S.M.

    1981-01-01

    Field experiments conducted on 12,500 pumps in India found that more than 85% of the pump sets were inefficient, making the consumption of electricity or diesel fuel over 150% above normal requirements. It also established that the farmers were not aware that they were wasting energy or that it could be corrected. Experts from the Institute of Co-operative Management who identified the factors causing energy waste and specified remedial measures felt that the most effective method for educating the farmers was through field level demonstrations and word-of-mouth communication at 50 sites. They demonstrated a low-resistance foot valve and other remedial measures that could cut fuel use by 38% or electricity use by 28%. The investment and benefits were calculated at each site. The new foot valve was found to be the most effective measure, followed by replacement of undersized suction pipes with rigid polyvinyl chloride pipes. 5 figures, 24 tables.

  11. Proposal of Unique Process Pump with Floating Type Centrifugal Impeller (Preliminarily Report : Axial Thrust of Impeller with Driving Shaft)

    Science.gov (United States)

    Kawashima, Ryunosuke; Kanemoto, Toshiaki; Sakamoto, Kengo; Uno, Mitsuo

    2010-06-01

    The authors have proposed the unique centrifugal pump, in which the impeller dose not have the driving shaft but is driven by the magnetic induction, namely Lorentz force, without the stay. Then, the rotating posture of the impeller is not stable, just like UFO. To make the rotating posture of the impeller stable irrespective of the operating condition, the pressure in the impeller casing was investigated experimentally while the impeller rotates at the steady state, as the preliminarily stage. The pressure, as well known, fluctuates periodically in response to the blade number. Besides, the pressure on the impeller shrouds decreases with the increase of the gap between the front shroud and the suction cover where the water leaks to the suction pipe, and is distorted in the peripheral direction. Such pressure conditions contribute directly to the hydraulic force acting on the impeller. The unstable behaviors of the impeller are induced from the above hydraulic forces, which change unsteadily in the radial and the peripheral directions in the impeller casing. The forces are affected by not only the operating condition but also the rotating posture of the impeller.

  12. Fabricating Zr-Based Bulk Metallic Glass Microcomponent by Suction Casting Using Silicon Micromold

    Directory of Open Access Journals (Sweden)

    Zhijing Zhu

    2014-08-01

    Full Text Available A suction casting process for fabricating Zr55Cu30Al10Ni5 bulk metallic glass microcomponent using silicon micromold has been studied. A complicated BMG microgear with 50 μm in module has been cast successfully. Observed by scanning electron microscopy and laser scanning confocal microscopy, we find that the cast microgear duplicates the silicon micromold including the microstructure on the surface. The amorphous state of the microgear is confirmed by transmission election microscopy. The nanoindentation hardness and elasticity modulus of the microgear reach 6.5 GPa and 94.5 GPa. The simulation and experimental results prove that the suction casting process with the silicon micromold is a promising one-step method to fabricate bulk metallic glass microcomponents with high performance for applications in microelectromechanical system.

  13. Magnetohydrodynamics effect on three-dimensional viscous incompressible flow between two horizontal parallel porous plates and heat transfer with periodic injection/suction

    Directory of Open Access Journals (Sweden)

    R. C. Chaudhary

    2004-11-01

    Full Text Available We investigate the hydromagnetic effect on viscous incompressible flow between two horizontal parallel porous flat plates with transverse sinusoidal injection of the fluid at the stationary plate and its corresponding removal by periodic suction through the plate in uniform motion. The flow becomes three dimensional due to this injection/suction velocity. Approximate solutions are obtained for the flow field, the pressure, the skin-friction, the temperature field, and the rate of heat transfer. The dependence of solution on M (Hartmann number and λ (injection/suction is investigated by the graphs and tables.

  14. Evaluation of reciprocating electromagnetic air pumping for portable PEMFC

    International Nuclear Information System (INIS)

    Kwon, Kilsung; Kang, Ho; Kang, Seongwon; Kim, Daejoong

    2013-01-01

    In this paper, we present a proton exchange membrane fuel cell (PEMFC) integrated with an electromagnetic (EM) air pump. The EM air pump provides the PEMFC with air by reciprocating motions of the permanent magnet attached to a flexible membrane. We performed a parametric study to decide the optimal dimensions of the reciprocating EM air pump. The effects of various operating parameters on the EM air pump were investigated with the root-mean-square (RMS) flow rate and current. A core with a higher relative permeability shows better performance. The RMS current linearly increases with the applied voltage and shows no dependence on the frequency. The RMS flow rate also increases with the voltage. The RMS flow rate per power consumption is highest at the frequency around 20 Hz and decreases as the applied voltage increases. When the reciprocating EM air pump was used to supply air to the portable PEMFC, it was found that the power density of the PEMFC increases with the applied voltage and shows the highest performance at the frequency of 10 Hz. We compared the performance of the PEMFC between the flow meter and the EM air pump used as an air supplier. About 81% of the output power using the flow meter was obtained when the EM air pump is operated at the applied voltage of 5 V. The parasitic power ratio reaches at its minimum value about 0.1 with an EM applied voltage of 0.25V. (paper)

  15. Suction removal of sediment from between armour blocks. Part 2. Waves

    DEFF Research Database (Denmark)

    Dixen, Figen Hatipoglu; Sumer, B. Mutlu; Fredsøe, Jørgen

    2008-01-01

    When a stone/armor layer on a sand bed is exposed to flow, the sand underneath will be agitated by the flow turbulence. When the flow velocity reaches a critical value, the sand will be sucked (winnowed out) from between the armor blocks. In a previous investigation, we studied suction removal of...

  16. The impact of soil suction variation on earthquake intensity indices

    Directory of Open Access Journals (Sweden)

    Biglari Mahnoosh

    2016-01-01

    Full Text Available Soil properties can completely change the ground motion characteristics as they travel from the bedrock to the surface because, soil as a low-pass filter, may amplify or deamplify seismic motions in some frequencies on the wave travelling path. Recent studies about the advanced unsaturated soil mechanics clearly shows that dynamic properties of soils, including small-strain shear modulus (Gmax, shear modulus reduction (G/Gmax, and damping ratio (D curves are affected by changes in the soil suction level. The current study present nonlinear time-dependent analysis of three different unsaturated soils available in the literature with different ranges of nonlinear behaviour that earlier have been studied on unsaturated dynamic models. Since, the earthquake intensity parameters can be used to describe the damage potential of an earthquake, the focus of this paper is to evaluate the impact of the suction variation on the engineering ground motion parameters, including peak values of strong motion, Vmax/Amax, root-mean-square acceleration, Arias intensity, characteristic intensity, cumulative absolute velocity, acceleration spectrum intensity, effective design acceleration, A95 parameter and predominant period separately under the near-field and the far-field seismicity categories.

  17. Detailed Balance Limit of Efficiency of Broadband-Pumped Lasers.

    Science.gov (United States)

    Nechayev, Sergey; Rotschild, Carmel

    2017-09-13

    Broadband light sources are a wide class of pumping schemes for lasers including LEDs, sunlight and flash lamps. Recently, efficient coupling of broadband light to high-quality micro-cavities has been demonstrated for on-chip applications and low-threshold solar-pumped lasers via cascade energy transfer. However, the conversion of incoherent to coherent light comes with an inherent price of reduced efficiency, which has yet to be assessed. In this paper, we derive the detailed balance limit of efficiency of broadband-pumped lasers and discuss how it is affected by the need to maintain a threshold population inversion and thermodynamically dictated minimal Stokes' shift. We show that lasers' slope efficiency is analogous to the nominal efficiency of solar cells, limited by thermalisation losses and additional unavoidable Stokes' shift. The lasers' power efficiency is analogous to the detailed balance limit of efficiency of solar cells, affected by the cavity mirrors and impedance matching factor, respectively. As an example we analyze the specific case of solar-pumped sensitized Nd 3+ :YAG-like lasers and define the conditions to reach their thermodynamic limit of efficiency. Our work establishes an upper theoretical limit for the efficiency of broadband-pumped lasers. Our general, yet flexible model also provides a way to incorporate other optical and thermodynamic losses and, hence, to estimate the efficiency of non-ideal broadband-pumped lasers.

  18. Reactor coolant pump type RUV for Westinghouse Electric Company LLC reactor AP1000 TM

    International Nuclear Information System (INIS)

    Baumgarten, S.; Brecht, B.; Bruhns, U.; Fehring, P.

    2010-01-01

    The RUV is a reactor coolant pump, specially designed for the Westinghouse Electric Company LLC AP1000 TM reactor. It is a hermetically sealed, wet winding motor pump. The RUV is a very compact, vertical pump/motor unit, designed to fit into the compartment next to the reactor pressure vessel. Each of the two steam generators has two pump casings welded to the channel head by the suction nozzle. The pump/motor unit consists of a pump part, where a semi-axial impeller/diffuser combination is mounted in a one-piece pump casing. Computational Fluid Dynamics methods combined with various hydraulic tests in a 1:2 scale hydraulic test assure full compliance with the specific customer requirements. A short and rigid shaft, supported by a radial bearing, connects the impeller with the high inertia flywheel. This flywheel consists of a one-piece forged stainless steel cylinder, with an option for several smaller heavy metal cylinders inside. The flywheel is located inside the thermal barrier, which forms part of the pressure boundary. A specific arrangement of cooling water circuits guarantees a homogeneous temperature distribution in and around the flywheel, minimizes the friction losses of the flywheel and protects the motor from hot coolant. The driving torque is transmitted by the motor shaft, which itself is supported by two radial bearings. A three-phase, high-voltage squirrel-cage induction motor generates the driving torque. Due to the wet winding concept it is possible to achieve positive effects regarding motor lifetime. The cooling water is forced through the stator windings and the gap between rotor and stator by an auxiliary impeller. Furthermore, this wet winding motor concept has higher efficiency as compared to a canned motor since there are no eddy current losses. As part of the design process and in addition to the hydraulic scale model, a complete half scale model pump was built. It was used to verify the calculations performed like coast

  19. INCOMPRESSIBLE LAMINAR BOUNDARY LAYER CONTROL BY BLOWING AND SUCTION

    OpenAIRE

    AZZEDINE NAHOUI; LAKHDAR BAHI

    2013-01-01

    A two-dimensional incompressible laminar boundary layer and its control using blowing and suction over a flat plate and around the NACA 0012 and 661012 profiles, is studied numerically. The study is based on the Prandtl boundary layer model using the finite differences method and the Crank-Nicolson scheme. The velocity distribution, the boundary layer thickness and the friction coefficient, are determined and presented with and without control. The application of the control technique, has de...

  20. Unleashing Flexibility from Electric Boilers and Heat Pumps in Danish Residential Distribution Network

    DEFF Research Database (Denmark)

    Sinha, Rakesh; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2018-01-01

    and thereby improving its techno-economic efficiency. The data used for the evaluation are also from the real household sites in Denmark provided by the district heating utility. Focus is on the low-voltage grid, and that’s very relevant since many doesn’t expect any flexibility from that voltage level. Study...... this model is compared to responses from an average model of the hot water storage tank to evaluate the benefit of the more detailed model. Finally, analysis on consumption patterns of electrical and thermal loads in residential buildings in Northern Jutland, Denmark, are used for analysis of the system...... and use of thermal units as flexible consumer loads in the low voltage (LV) distribution network grid. The models of EB and HP with storage tank are briefly discussed in relation to the actual control and flexibility based on grid condition and status of storage tank temperature or position...

  1. Pumping behavior of sputter ion pumps

    International Nuclear Information System (INIS)

    Chou, T.S.; McCafferty, D.

    The ultrahigh vacuum requirements of ISABELLE is obtained by distributed pumping stations. Each pumping station consists of 1000 l/s titanium sublimation pump for active gases (N 2 , H 2 , O 2 , CO, etc.), and a 20 l/s sputter ion pump for inert gases (methane, noble gases like He, etc.). The combination of the alarming production rate of methane from titanium sublimation pumps (TSP) and the decreasing pumping speed of sputter ion pumps (SIP) in the ultrahigh vacuum region (UHV) leads us to investigate this problem. In this paper, we first describe the essential physics and chemistry of the SIP in a very clean condition, followed by a discussion of our measuring techniques. Finally measured methane, argon and helium pumping speeds are presented for three different ion pumps in the range of 10 -6 to 10 -11 Torr. The virtues of the best pump are also discussed

  2. A Constitutive Model for Unsaturated soils based on a Compressibility Framework dependent on Suction and Degree of Saturation

    OpenAIRE

    Sitarenios Panagiotis; Kavvadas Michael

    2016-01-01

    The Modified Cam Clay model is extended to account for the behaviour of unsaturated soils using Bishop’s stress. To describe the Loading – Collapse behaviour, the model incorporates a compressibility framework with suction and degree of saturation dependent compression lines. For simplicity, the present paper describes the model in the triaxial stress space with characteristic simulations of constant suction compression and triaxial tests, as well as wetting tests. The model reproduces an evo...

  3. Investigation on creep behavior of geo-materials with suction control technique

    Directory of Open Access Journals (Sweden)

    Nishimura Tomoyoshi

    2016-01-01

    Full Text Available The compacted bentonite which has typical couple problem associated to thermal - hydration - mechanical – chemical (THMC consist of one component of engineered barrier. Recently, the couple THMC formulation modelling suggested by some researchers can be predicted basically phenomena for engineered barrier that approach to correct evaluate satisfied facilities. The compacted bentonite is essentially unsaturated condition, some behaviors for bentonite has similar or close with generally expansive unsaturated soils. Therefore, hydrations have given significant influence on deformation of compacted bentonite such as swelling. There are many researches for swelling behavior of compacted bentonite within soaking. Extended theoretical or experimental investigations for unsaturated soil mechanics are possible to describe the strength-deformation behavior of compacted bentonite with suction controlling principle. A new method of determining the failure phase such as great axis deformation and destructions like strip of surface in the laboratory is described and the creep behavior of compacted bentonite is considered under maintain of high relative humidity environment. The creep deformation measured using improved cyclic relative humidity control apparatus in terms of specific suction control technique.

  4. Comparison of numerical formulations for the modeling of tensile loaded suction buckets

    DEFF Research Database (Denmark)

    Sørensen, Emil Smed; Clausen, Johan Christian; Damkilde, Lars

    2017-01-01

    The tensile resistance of a suction bucket is investigated using three different numerical formulations. The first formulation utilizes the three-field u-p-U formulation accounting for solid and fluid displacements, u and U, as well as the pore-fluid pressure, p. The two other formulations compri...

  5. Long term effects of cyclic loading on suction caisson foundations in sand

    NARCIS (Netherlands)

    Lupea, C.; Thijssen, R.; Van Tol, A.F.

    2014-01-01

    Offshore wind turbine projects have been characterised by an increase in costs, sizes and distances from shore, EWEA 2012 This created a need of investigating the adequacy of alternative and more fìnancially attractive foundation types such as suction caissons. Within a multi-footing configuration,

  6. Kinematics of suction feeding in the seahorse Hippocampus reidi.

    Science.gov (United States)

    Roos, Gert; Van Wassenbergh, Sam; Herrel, Anthony; Aerts, Peter

    2009-11-01

    Fish typically use a rostro-caudal wave of head expansion to generate suction, which is assumed to cause a uni-directional, anterior-to-posterior flow of water in the expanding head. However, compared with typical fish, syngnathid fishes have a remarkably different morphology (elongated snout, small hyoid, immobile pectoral girdle) and feeding strategy (pivot feeding: bringing the small mouth rapidly close to the prey by neurocranial dorsorotation). As a result, it is unclear how suction is generated in Syngnathidae. In this study, lateral and ventral expansions of the head were quantified in Hippocampus reidi and linked to the kinematics of the mouth, hyoid and neurocranium. In addition, the flow velocities inside the bucco-pharyngeal cavity and in front of the mouth were calculated. Our data suggest that the volume changes caused by lateral expansion are dominant over ventral expansion. Maximum gape, neurocranium rotation and hyoid depression are all reached before actual volume increase and before visible prey movement. This implies that, unlike previously studied teleosts, hyoid rotation does not contribute to ventral expansion by lowering the floor of the mouth during prey capture in H. reidi. The lateral volume changes show a rostro-caudal expansion, but the maximal flow velocity is not near the mouth aperture (as has been demonstrated for example in catfish) but at the narrow region of the buccal cavity, dorsal to the hyoid.

  7. Smart Dual-Mode Heat Pump With HP2Grid Functionality To Support Large-Scale Integration Of Intermittent Renewables

    DEFF Research Database (Denmark)

    Carmo, Carolina; Blarke, Morten Boje

    2013-01-01

    materials and the ability to generate electricity back to the grid. This new concept will not only improve the residential thermal supply system efficiency by 30-40 %, but will also extend the current intra-day flexibility of heat pumps to a wider range of flexible uses. In this paper, we will investigate...

  8. Design of BOP Systems for the AM600

    Energy Technology Data Exchange (ETDEWEB)

    Ouma, Victor Otieno; Abdoelatef, M. Gomaa; Na, Hyungjooh; Field, Robert [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2015-10-15

    Targeted for emergent nuclear countries with smaller grid capacity and/or large seasonal variation in grid frequency, the design is intended to be appropriate as an initial Nuclear Power Plant (NPP) installation. The AM600 shaftline is designed to have low capital and installation cost with robust resistance to torsional vibration and other operational insults. The proposed AM600 design for pumping condensate from the hotwell to the SGFP suction is a horizontal CP/CBP combination. This design avoids many of the problems associated with vertical condensate pumps as outlined above. Further, this design represents a robust, reliable, approach with simplified maintenance and overhauls. Finally, this design has been specified and used by a major U.S. NPP operator at twelve nuclear units with more than 10 million cumulative 'pump set' operating hours with very reliable performance. The specification of a single stage, double hung, double suction barrel pump for the SGFPs avoids design issues associated with horizontal split case pumps and with multiple impeller designs. The use of electronic VFD to drive a variable speed motor simplifies the design, fabrication, and installation of the SGFP driver. Further, it eliminates the need for a 'startup' SGFP and permits use of the SGFPs independent of having a vacuum in the main condenser. The main characteristics of the design specification for the AM600 FWHs is that they consist of a single string. Moreover, four (4) LP FWHs are located in the condenser neck. Modularizing the installation of FWHs can bring significant economies by a reduction in installation work in the field with an associated reduction in erection schedules. However, the design with a single string limits operational flexibility to take a FWH out-of-service to address tube rupture.

  9. Successful Laparoscopically Assisted Transcervical Suction Evacuation of Interstitial Pregnancy following Failed Methotrexate Injection in a Community Hospital Setting

    Directory of Open Access Journals (Sweden)

    Rani B. Fritz

    2014-01-01

    Full Text Available We report on a case of a patient with an early diagnosed cornual ectopic pregnancy following failed methotrexate treatment. The patient was subsequently taken to the operating room for a laparoscopic guided transcervical suction curettage of the cornual ectopic. The surgery was successful and the patient was followed up until her urine pregnancy test was negative. We conclude that in properly selected patients, cornual ectopic pregnancy may be treated with transcervical suction curettage.

  10. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Liu

    2015-01-01

    Full Text Available This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT, ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (Crs decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2 % at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV.

  11. Aerosol distribution during open suctioning and long-term surveillance of air quality in a respiratory care center within a medical center.

    Science.gov (United States)

    Chung, Fen-Fang; Lin, Hui-Ling; Liu, Hsueh-Erh; Lien, Angela Shin-Yu; Hsiao, Hsiu-Feng; Chou, Lan-Ti; Wan, Gwo-Hwa

    2015-01-01

    The investigation of hospital air quality has been conducted in wards, ICUs, operating theaters, and public areas. Few studies have assessed air quality in respiratory care centers (RCCs), especially in mechanically ventilated patients with open suctioning. The RCC air quality indices (temperature, relative humidity, levels of CO2, total volatile organic compounds, particulate matter [PM], bacteria, and fungi) were monitored over 1 y. The air around the patient's head was sampled during open suctioning to examine the probability of bioaerosol exposure affecting health-care workers. This investigation found that the levels of indoor air pollutants (CO2, PM, bacteria, and fungi) were below the indoor air quality standard set by the Taiwan Environmental Protection Agency. Meanwhile, the levels of total volatile organic compounds sometimes exceeded the indoor air quality standard, particularly in August. The identified bacterial genera included Micrococcus species, Corynebacterium species, and Staphylococcus species, and the predominant fungal genera included yeast, Aspergillus species, Scopulariopsis species, and Trichoderma species. Additionally, airborne PM2.5, PM1, and bacteria were clearly raised during open suctioning in mechanically ventilated patients. This phenomenon demonstrated that open suctioning may increase the bacterial exposure risk of health-care workers. RCC air quality deserves long-term monitoring and evaluation. Health-care workers must implement self-protection strategies during open suctioning to ensure their occupational health and safety in health-care settings. Copyright © 2015 by Daedalus Enterprises.

  12. Development in corrosion resistance by microstructural refinement in Zr-16 SS 304 alloy using suction casting technique

    Energy Technology Data Exchange (ETDEWEB)

    Das, N., E-mail: nirupamd@barc.gov.in; Sengupta, P.; Abraham, G.; Arya, A.; Kain, V.; Dey, G.K.

    2016-08-15

    Highlights: • Grain refinement was made in Zr–16 wt.% SS alloy while prepared by suction casting process. • Distribution of Laves phase, e.g., Zr{sub 2}(Fe, Cr) was raised in suction cast (SC) Zr–16 wt.% SS. • Corrosion resistance was improved in SC alloy compared to that of arc-melt-cast alloy. • Grain refinement in SC alloy assisted for an increase in its corrosion resistance. - Abstract: Zirconium (Zr)-stainless steel (SS) hybrid alloys are being considered as baseline alloys for developing metallic-waste-form (MWF) with the motivation of disposing of Zr and SS base nuclear metallic wastes. Zr–16 wt.% SS, a MWF alloy optimized from previous studies, exhibit significant grain refinement and changes in phase assemblages (soft phase: Zr{sub 2}(Fe, Cr)/α-Zr vs. hard phase: Zr{sub 3}(Fe, Ni)) when prepared by suction casting (SC) technique in comparison to arc-cast-melt (AMC) route. Variation in Cr-distribution among different phases are found to be low in suction cast alloy, which along with grain refinement restricted Cr-depletion at the Zr{sub 2}(Fe, Cr)/Zr interfaces, prone to localized attack. Hence, SC alloy, compared to AMC alloy, showed lower current density, higher potential at the breakdown of passivity and higher corrosion potential during polarization experiments (carried out under possible geological repository environments, viz., pH 8, 5 and 1) indicating its superior corrosion resistance.

  13. On the influence of buoyancy and suction/injection In Heat and Mass ...

    African Journals Online (AJOL)

    In this paper, we examined the influence of buoyancy and suction/injection in the problem of unsteady convection with chemical reaction and radiative heat transfer past a flat porous plate moving through a binary mixture in an optically thin environment is presented. The dimensionless governing equations for this ...

  14. Optimum Aggregation and Control of Spatially Distributed Flexible Resources in Smart Grid

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Mendaza, Iker Diaz de Cerio; Myers, Kurt S.

    2018-01-01

    system operators (DSOs) to make faster operational decisions. Moreover, the aggregation enables flexibility from small distributed flexible resources to be traded to different power and energy markets. A hierarchical control architecture comprising a combination of centralized and decentralized control...... is demonstrated through simulation of three operational scenarios in a real low voltage distribution system having high penetrations of electric vehicles and heat pumps. The simulation results demonstrated that the aggregation helps DSOs not only in taking faster operational decisions, but also in effectively...

  15. Key techniques for space-based solar pumped semiconductor lasers

    Science.gov (United States)

    He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

    2014-12-01

    In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

  16. Development of a rotary clap mechanism for positive-displacement rotary pumps: Kinematic analysis and working principle

    International Nuclear Information System (INIS)

    Shim, Sung Bo; Kim, Kyeong Uk; Park, Young Jun; Kim, Jong Mun

    2015-01-01

    A five-bar spatial mechanism named as a rotary clap mechanism is developed as a pumping device for positive displacement rotary pumps. The mechanism comprises a driving crank, a shaft link with two pins and two gears mounted on the middle and both ends, two rotors with jaws equally spaced along their circumferences, and two fixed internal gears. As the crank rotates, the gear pin-jointed to the crank rotates about the crank pin and at the same time rotates about the center of the fixed internal gears like a hypo-cyclic gear train. The gear-attached shaft link also rotates about the crank pin and about the fixed internal gears at the same time. This motion of the shaft link makes the pins rotate about the center of the fixed internal gears with a periodically varying radius. Therefore, two rotors driven by the pins rotate with different angular velocities. One rotor alternately leads and lags relative to the other rotor. These lead-lag motions between the two jaws of the rotors, which result in suction and discharge required for pumping, resemble hand clapping from which the mechanism was named. Construction and design parameters of the rotary clap mechanism are introduced, and kinematic analysis of this mechanism is performed. The relationships among design parameters, inherent constraints, and effects of design parameters on the is placement of mechanism are also presented.

  17. Method and means for abruptly terminating the flow of fluid in closed circulating systems of nuclear reactor plants or the like

    International Nuclear Information System (INIS)

    Schiele, O.; Florjancic, D.

    1976-01-01

    A nuclear steam supply system is described wherein each of a plurality of centrifugal pumps begins to operate with full cavitation in response to an abrupt drop of system pressure in the event of leakage. This is achieved by influencing the net positive suction head of each pump over the entire range of fluid flow and/or by influencing the net positive suction head upstream of the pumps. The first mode of causing the pumps to operate with full cavitation includes an appropriate selection of the inlet angle and/or inlet diameter of the pump impeller, the provision of auxiliary impellers which are located upstream of the pumps and can circulate the fluid in or counter to the direction of rotation of the respective pump impellers, or the provision of suitably curved guide vanes in the pumps. The second mode include interrupting the admission of undercooled fluid into the system upstream of the pumps

  18. Static pressure recovery analysis in the vane island diffuser of a centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    Si, Qiaorui [National Research Center of Pumps, Jiangsu University, Zhenjiang (China); Dupont, Patrick; Bayeul-Laine, Annie-Claude; Dazin, Antoine; Roussette, Olivier; Bois, Gerard [LML, UMR CNRS 8107 Ecole Centrale de Lille, Lille (France)

    2016-02-15

    The overall performance of a vane-island type diffuser of a centrifugal pump model was obtained by means of directional probe traverses. These measurements were performed in an air model of a real hydraulic pump for five volume flow rates. Directional probe traverses are performed with a classical three-hole probe to cover most of the complete inlet section of the diffuser from hub to shroud and from pressure to suction side. Existing Particle image velocimetry (PIV) measurement results are also used to compare probe measurement results between the inlet and outlet throats of vane island diffuser at mid-span. Some assistance from already existing unsteady calculation, including leakage effects, is used to evaluate the numerical approach capability and to correctly define the mean initial conditions at impeller's outlet section. Pressure recovery and the measured total pressure loss levels inside this particular vane diffuser geometry are then calculated. Detailed analysis of the flow structure at the inlet section of the vane island diffuser is presented to focus on pressure evolution inside the entire diffuser section for different flow rates. The combined effects of incidence angle and blockage distributions along hub to shroud direction are found to play an important role on loss distribution in such a diffuser.

  19. Real-Time Congestion Management in Distribution Networks by Flexible Demand Swap

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei

    2017-01-01

    In addition to the day-ahead congestion management in distribution networks, the real-time congestion management is very important because many unforeseen events can occur at the real operation time, e.g. loss of generation of distributed energy resources (DERs) or inaccurate forecast of energy...... pumps (HPs) for real time congestion management. The swap method can maintain the power balance of the system and avoid the imbalance cost of activating the flexibility service. An algorithm for forming swaps through optimal power flow (OPF) and mixed integer linear programming (MILP) is proposed...... consumption or production. Flexibility service from demand will be a good option to solve the real-time congestions if the cost of activating the flexibility service is fully addressed. This paper proposes a new method, namely “swap”, to employ the flexibility service from electric vehicles (EVs) and heat...

  20. Boundary layer on a flat plate with suction; Couche limite sur paroi plane poreuse avec aspiration

    Energy Technology Data Exchange (ETDEWEB)

    Favre, A; Dumas, R; Verollet, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Institut de Mecanique Statistique de la Turbulence, Faculte des Sciences de Marseille, 13 (France)

    1961-07-01

    This research done in wind tunnel concerns the turbulent boundary layer of a porous flat plate with suction. The porous wall is 1 m long and begins 1 m downstream of the leading edge. The Reynolds number based on the boundary layer thickness is of the order of 16.300. The suction rate defined as the ratio of the velocity perpendicular to the wall to the external flow velocity ranges from 0 to 2 per cent. The pressure gradient can be controlled. The mean velocity profiles have been determined for various positions and suction rates by means of total pressure probes together with the intensities of the turbulent velocity fluctuations components, energy spectra and correlations by means of hot wire anemometers, spectral analyser and correlator. The stream lines, the values of the viscous and turbulent shear stresses, of the local wall friction, of the turbulent energy production term, with some information on the dissipation of the energy have been derived from these measurements. For these data the integral of equation of continuity in boundary layer have been drawn. The suction effects on the boundary layer are important. The suction thoroughly alters the mean velocity profiles by increasing the viscous shear stresses near the wall and decreasing them far from the wall, it diminishes the longitudinal and transversal turbulence intensities, the turbulent shear stresses, and the production of energy of turbulence. These effects are much stressed in the inner part of the boundary layer. On the other hand the energy spectra show that the turbulence scale is little modified, the boundary layer thickness being not much diminished by the suction. The suction effects can be appreciated by comparing twice the suction rate to the wall friction coefficient (assumed airtight), quite noticeable as soon as the rate is about unity, they become very important when it reaches ten. (author) [French] Ces recherches, effectuees en soufflerie, concernent la couche limite turbulente d

  1. Shaping of picosecond pulses for pumping optical parametric amplification

    International Nuclear Information System (INIS)

    Fueloep, J.A.; Krausz, F.; Major, Zs.; Horvath, B.

    2006-01-01

    Complete test of publication follows. The use of temporally shaped pump pulses for optical parametric amplification (OPA) is expected to facilitate an increase of efficiency and suppression of possible spectral distortions in this process, since the gain sensitively depends on the pump intensity. Our simulations confirmed such beneficial effect of temporally shaped pump pulses on the OPA process. With the aim to realize an optimized OPA stage pumped by shaped pulses, a novel method for passively shaping narrow band picosecond pulses has been developed. The method is based on the pulse-stacking principle, where replicas of the incoming pulse are created in a specially designed four-beam interferometer. The replicas are recombined with appropriate delays. The interferometer design allows for a unique flexibility in varying the pulse shape, since all relevant degrees of freedom, such as relative intensities and delays between the pulse replicas are independently adjustable. According to our calculations a pulse with a flat-top time profile would provide optimal conditions in the OPA process. Usually the pump pulse needs to be amplified in a conventional laser amplifier prior to the OPA. Our cross-correlation measurements showed that we are able to obtain shaped amplified pulses by shaping the amplifier input. Furthermore, by precompensating the distortions introduced by the amplifier we demonstrated our capability to produce amplified pulses with a flat-top time profile.

  2. Saline instillation before tracheal suctioning decreases the incidence of ventilator-associated pneumonia.

    Science.gov (United States)

    Caruso, Pedro; Denari, Silvia; Ruiz, Soraia A L; Demarzo, Sergio E; Deheinzelin, Daniel

    2009-01-01

    To compare the incidence of ventilator-associated pneumonia (VAP) with or without isotonic saline instillation before tracheal suctioning. As a secondary objective, we compared the incidence of endotracheal tube occlusion and atelectasis. Randomized clinical trial. The study was conducted in a medical surgical intensive care unit of an oncologic hospital. We selected consecutive patients needing mechanical ventilation for >72 hrs. Patients were allocated into two groups: a saline group that received instillation of 8 mL of saline before tracheal suctioning and a control group which did not. VAP was diagnosed based on clinical suspicion and confirmed by bronchoalveolar lavage quantitative culture. The incidence of atelectasis on daily chest radiography and endotracheal tube occlusions were recorded. The sample size was calculated to a power of 80% and a type I error probability of 5%. One hundred thirty patients were assigned to the saline group and 132 to the control group. The baseline demographic variables were similar between groups. The rate of clinically suspected VAP was similar in both groups. The incidence of microbiological proven VAP was significantly lower in the saline group (23.5% x 10.8%; p = 0.008) (incidence density/1.000 days of ventilation 21.22 x 9.62; p < 0.01). Using the Kaplan-Meier curve analysis, the proportion of patients remaining without VAP was higher in the saline group (p = 0.02, log-rank test). The relative risk reduction of VAP in the saline instillation group was 54% (95% confidence interval, 18%-74%) and the number needed to treat was eight (95% confidence interval, 5-27). The incidence of atelectases and endotracheal tube occlusion were similar between groups. Instillation of isotonic saline before tracheal suctioning decreases the incidence of microbiological proven VAP.

  3. Reliability analysis of stiff versus flexible piping

    International Nuclear Information System (INIS)

    Lu, S.C.

    1985-01-01

    The overall objective of this research project is to develop a technical basis for flexible piping designs which will improve piping reliability and minimize the use of pipe supports, snubbers, and pipe whip restraints. The current study was conducted to establish the necessary groundwork based on the piping reliability analysis. A confirmatory piping reliability assessment indicated that removing rigid supports and snubbers tends to either improve or affect very little the piping reliability. The authors then investigated a couple of changes to be implemented in Regulatory Guide (RG) 1.61 and RG 1.122 aimed at more flexible piping design. They concluded that these changes substantially reduce calculated piping responses and allow piping redesigns with significant reduction in number of supports and snubbers without violating ASME code requirements. Furthermore, the more flexible piping redesigns are capable of exhibiting reliability levels equal to or higher than the original stiffer design. An investigation of the malfunction of pipe whip restraints confirmed that the malfunction introduced higher thermal stresses and tended to reduce the overall piping reliability. Finally, support and component reliabilities were evaluated based on available fragility data. Results indicated that the support reliability usually exhibits a moderate decrease as the piping flexibility increases. Most on-line pumps and valves showed an insignificant reduction in reliability for a more flexible piping design

  4. Adsorption pump for helium pumping out

    International Nuclear Information System (INIS)

    Donde, A.L.; Semenenko, Yu.E.

    1981-01-01

    Adsorption pump with adsorbent cooling by liquid helium is described. Shuttered shield protecting adsorbent against radiation is cooled with evaporating helium passing along the coil positioned on the shield. The pump is also equipped with primed cylindrical shield, cooled with liquid nitrogen. The nitrogen shield has in the lower part the shuttered shield, on the pump casing there is a valve used for pump pre-burning, and valves for connection to recipient as well. Pumping- out rates are presented at different pressures and temperatures of adsorbent. The pumping-out rate according to air at absorbent cooling with liquid nitrogen constituted 5x10 -4 Pa-3000 l/s, at 2x10 -2 Pa-630 l/s. During the absorbent cooling with liquid hydrogen the pumping-out rate according to air was at 4x10 -4 Pa-580 l/s, at 2x10 -3 Pa-680 l/s, according to hydrogen - at 8x10 -5 Pa-2500 l/s, at 5x10 -3 Pa-4200 l/s. During adsorbent cooling with liquid helium the rate of pumping-out according to hydrogen at 3x10 5 Pa-2400% l/s, at 6x10 3 Pa-1200 l/s, and according to helium at 3.5x10 -5 Pa-2800 l/s, at 4x10 -3 Pa-1150 l/s. The limit vacuum is equal to 1x10 -7 Pa. The volume of the vessel with liquid helium is equal to 3.5 l. Helium consumption is 80 cm 3 /h. Consumption of liquid nitrogen from the shield is 400 cm 3 /h. The limit pressure in the pump is obtained after forevacuum pumping-out (adsorbent regeneration) at 300 K temperature. The pump is made of copper. The pump height together with primed tubes is 800 mm diameter-380 mm [ru

  5. Wind power integration with heat pumps, heat storages, and electric vehicles - Energy systems analysis and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hedegaard, K.

    2013-09-15

    This PhD investigates to which extent heat pumps, heat storages, and electric vehicles can support the integration of wind power. Considering the gaps in existing research, the main focus is put on individual heat pumps in the residential sector (one-family houses) and the possibilities for flexible operation, using the heat storage options available. Several energy systems analyses are performed using the energy system models, Balmorel, developed at the former TSO, ElkraftSystem, and, EnergyPLAN, developed at Aalborg University. The Danish energy system towards 2030, with wind power penetrations of up to 60 %, is used as a case study in most of the analyses. Both models have been developed further, resulting in an improved representation of individual heat pumps and heat storages. An extensive model add-on for Balmorel renders it possible to optimise investment and operation of individual heat pumps and different types of heat storages, in integration with the energy system. Total costs of the energy system are minimised in the optimisation. The add-on incorporates thermal building dynamics and covers various different heat storage options: intelligent heat storage in the building structure for houses with radiator heating and floor heating, respectively, heat accumulation tanks on the space heating circuit, as well as hot water tanks. In EnergyPLAN, some of the heat storage options have been modelled in a technical optimisation that minimises fuel consumption of the energy system and utilises as much wind power as possible. The energy systems analyses reveal that in terms of supporting wind power integration, the installation of individual heat pumps is an important step, while adding heat storages to the heat pumps is less influential. When equipping the heat pumps with heat storages, only moderate system benefits can be gained. Hereof, the main system benefit is that the need for peak/reserve capacity investments can be reduced through peak load shaving; in

  6. Boundary layer development on turbine airfoil suction surfaces

    Science.gov (United States)

    Sharma, O. P.; Wells, R. A.; Schlinker, R. H.; Bailey, D. A.

    1981-01-01

    The results of a study supported by NASA under the Energy Efficient Engine Program, conducted to investigate the development of boundary layers under the influence of velocity distributions that simulate the suction sides of two state-of-the-art turbine airfoils, are presented. One velocity distribution represented a forward loaded airfoil ('squared-off' design), while the other represented an aft loaded airfoil ('aft loaded' design). These velocity distributions were simulated in a low-speed, high-aspect-ratio wind tunnel specifically designed for boundary layer investigations. It is intended that the detailed data presented in this paper be used to develop improved turbulence model suitable for application to turbine airfoil design.

  7. Measuring lip force by oral screens Part 2: The importance of screen design, instruction and suction.

    Science.gov (United States)

    Wertsén, Madeleine; Stenberg, Manne

    2017-10-01

    The aim of this study was to find a reliable method for measuring lip force and to find the most important factors that influence the measurements in terms of magnitude and variability. The hypothesis tested was that suction is involved and thus the instruction and the design of the oral screen are of importance when measuring lip force. This is a methodological study in a healthy population. This study was conducted in a general community. The designs of the screens were soft and hard prefabricated screens and 2 semi-individually made with a tube allowing air to pass. The screens and the instructions squeeze or suck were tested on 29 healthy adults, one at a time and on 4 occasions. The test order of the screens was randomized. Data were collected during 4 consecutive days, and the procedure was repeated after 1 month. The participants were 29 healthy adult volunteers. The instruction was an important mean to distinguish between squeezing and sucking. The design of the screen affected the lip force so that it increases in relation to the projected area of the screen. A screen design with a tube allowing air to pass made it possible to avoid suction when squeezing. By measuring with and without allowing air to pass, it was possible to distinguish between suction related and not suction related lip force. The additional screen pressure when sucking was related to the ability to produce a negative intraoral pressure. In conclusion lip force increases in relation to the projected area of the screen, sucking generally increases the measured lip force and the additional screen pressure when sucking is related to the ability to produce a negative intraoral pressure.

  8. MHD Boundary Layer Flow of Dilatant Fluid in a Divergent Channel with Suction or Blowing

    International Nuclear Information System (INIS)

    Bhattacharyya, Krishnendu; Layek, G. C.

    2011-01-01

    An analysis is carried out to study a steady magnetohydrodynamic (MHD) boundary layer flow of an electrically conducting incompressible power-law non-Newtonian fluid through a divergent channel. The channel walls are porous and subjected to either suction or blowing of equal magnitude of the same kind of fluid on both walls. The fluid is permeated by a magnetic field produced by electric current along the line of intersection of the channel walls. The governing partial differential equation is transformed into a self-similar nonlinear ordinary differential equation using similarity transformations. The possibility of boundary layer flow in a divergent channel is analyzed with the power-law fluid model. The analysis reveals that the boundary layer flow (without separation) is possible for the case of the dilatant fluid model subjected to suitable suction velocity applied through its porous walls, even in the absence of a magnetic field. Further, it is found that the boundary layer flow is possible even in the presence of blowing for a suitable value of the magnetic parameter. It is found that the velocity increases with increasing values of the power-law index for the case of dilatant fluid. The effects of suction/blowing and magnetic field on the velocity are shown graphically and discussed physically. (fundamental areas of phenomenology(including applications))

  9. Economic valuation of heat pumps and electric boilers in the Danish energy system

    DEFF Research Database (Denmark)

    Nielsen, Maria Grønnegaard; Morales González, Juan Miguel; Zugno, Marco

    2016-01-01

    Heat pumps (HP) and electric immersion boilers (EB) have great potential to increase flexibility in energy systems. In parallel, decreasing taxes on electricity-based heat production are creating a more favorable economic environment for the deployment of these units in Denmark. In this paper, th...... by potential investors....

  10. The role of capacitance in a wind-electric water pumping system

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Shitao [West Texas A& M Univ., Canyon, TX (United States); Clark, R.N. [Conservation and Production Research Lab., Bushland, TX (United States)

    1997-12-31

    The development of controllers for wind-electric water pumping systems to enable the use of variable voltage, variable frequency electricity to operate standard AC submersible pump motors has provided a more efficient and flexible water pumping system to replace mechanical windmills. A fixed capacitance added in parallel with the induction motor improves the power factor and starting ability of the pump motor at the lower cut-in frequency. The wind-electric water pumping system developed by USDA-Agricultural Research Service, Bushland, TX, operated well at moderate wind speeds (5-12 m/s), but tended to lose synchronization in winds above 12 m/s, especially if they were gusty. Furling generally did not occur until synchronization had been lost and the winds had to subside before synchronization could be reestablished. The frequency needed to reestablish synchronization was much lower (60-65 Hz) than the frequency where synchronization was lost (70-80 Hz). As a result, the load (motor and pump) stayed off an excessive amount of time thus causing less water to be pumped and producing a low system efficiency. The controller described in this paper dynamically connects additional capacitance of the proper amount at the appropriate time to keep the system synchronized (running at 55 to 60 Hz) and pumping water even when the wind speed exceeds 15 m/s. The system efficiency was improved by reducing the system off-line time and an additional benefit was reducing the noise caused by the high speed blade rotation when the load was off line in high winds.

  11. Dynamically balanced, hydraulically driven compressor/pump apparatus for resonant free piston Stirling engines

    Science.gov (United States)

    Corey, John A.

    1984-05-29

    A compressor, pump, or alternator apparatus is designed for use with a resonant free piston Stirling engine so as to isolate apparatus fluid from the periodically pressurized working fluid of the Stirling engine. The apparatus housing has a first side closed by a power coupling flexible diaphragm (the engine working member) and a second side closed by a flexible diaphragm gas spring. A reciprocally movable piston is disposed in a transverse cylinder in the housing and moves substantially at right angles relative to the flexible diaphragms. An incompressible fluid fills the housing which is divided into two separate chambers by suitable ports. One chamber provides fluid coupling between the power diaphragm of the RFPSE and the piston and the second chamber provides fluid coupling between the gas spring diaphragm and the opposite side of the piston. The working members of a gas compressor, pump, or alternator are driven by the piston. Sealing and wearing parts of the apparatus are mounted at the external ends of the transverse cylinder in a double acting arrangement for accessibility. An annular counterweight is mounted externally of the reciprocally movable piston and is driven by incompressible fluid coupling in a direction opposite to the piston so as to damp out transverse vibrations.

  12. Effect of inflow discharges on the development of matric suction and volumetric water content for dike during overtopping tests

    Science.gov (United States)

    Hassan, Marwan A.; Ismail, Mohd A. M.

    2017-10-01

    The point of this review is to depict the impact of various inflow discharge rate releases on the instruments of matric suction and volumetric water content during an experimental test of spatial overtopping failure at school of civil engineering in universiti Sains of Malaysia. A dry sand dike was conducted inside small flume channel with twelve sensors of tensiometer and Time-Domain Reflectometer (TDR). Instruments are installed in the soil at different locations in downstream and upstream slopes of the dike for measuring the response of matric suction and volumetric water content, respectively. Two values of inflow discharge rates of 30 and 40 L/min are utilized as a part of these experiments to simulate the effectiveness of water reservoirs in erosion mechanism. The outcomes demonstrate that the matric suction and volumetric water content are decreased and increased, respectively for both inflow discharges. The higher inflow discharges accelerate the saturation of dike soil and the erosion process faster than that for the lower inflow discharges.

  13. Impact of insulin pump on quality of life of diabetic patients

    Directory of Open Access Journals (Sweden)

    Haider Ghazanfar

    2016-01-01

    Full Text Available Aim: Diabetes is an emerging health problem, both in developing and developed countries and has an enormous economic and social impact. The objective of our study was to find the impact of insulin pump on the quality of life of patients with type 2 diabetes (T2D and compare it to the quality of life of patients with T2D using an insulin pen. Subjects and Methods: This is a case–control study which was conducted among patients with T2D presenting between November 2014 and November 2015. A total of 83 patients with T2D, using insulin pump were enrolled in the study as cases and 322 patients with T2D not using insulin pump but using insulin pens were enrolled as controls. Short form-36 quality of life questionnaire was used for data collection. Results: Mean age of patients using insulin pump was 52.49 ± 9.28 while the mean age of patients not using insulin pump was 54.72 ± 16.87. Mean score of all domains in the questionnaire was found to be higher in patients using insulin pump as compared to patients not using insulin pumps (P < 0.05. In 81.1% of the patients, the insulin pump decreased the frequency of hypoglycemic episodes. Conclusion: Insulin pump has significantly improved the quality of life of patients in terms of better self-esteem, decreased stress, and better mood. It has resulted in improved physical health, meal time flexibility, and ease of travel. It allows patient to have more active participation in social and recreational activities improving their personal and family life.

  14. Pumping mechanisms in sputter-ion pumps low pressure operation

    International Nuclear Information System (INIS)

    Welch, K.M.

    1991-01-01

    It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 is pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump

  15. Treatment of herniated lumbar disc by percutaneous laser disc decompression combined with synchronous suction technique through syringe

    Institute of Scientific and Technical Information of China (English)

    Dhir B. Gurung; Gaojian Tao; Hongyi Lin; Yanning Qian; Jian Lin

    2007-01-01

    Objective: To compare the outcomes of percutaneous laser disc decompression (PLDD) and PLDD with synchronous suction through syringe in the patients with herniated lumbar disc (HLD). Methods: Forty-two patients with HLD on MRI and those who did not respond to conservative treatment for 6 weeks were randomly divided into group A and group B. In group A, the patients were treated with PLDD and those in group B with PLDD and synchronous suction through syringe. GaAIAS diode laser at 810 nm was used for the ablation in both groups. The treatment effect was evaluated by modified MacNab's criteria on the 7th, 30th and 90th day. Results: Evaluated by modified MacNab's criteria, the percentages of the excellent and good cases in total patients treated for group B and A were 80.95% and 57.14% on the 7th follow-up day, 85.71% and 66.67% on the 30th follow-up day, and 95.24% and 71.43% on the 90th follow-up day, respectively. Conclusion: Synchronous suction technique through syringe during PLDD improves the overall outcome in the treatment of herniated lumbar disc.

  16. Pumping mechanisms in sputter-ion pumps low pressure operation

    International Nuclear Information System (INIS)

    Welch, K.M.

    1991-01-01

    It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump. 13 refs., 5 figs., 1 tab

  17. Optical-response properties in an atom-assisted optomechanical system with a mechanical pump

    Science.gov (United States)

    Sun, Xue-Jian; Chen, Hao; Liu, Wen-Xiao; Li, Hong-Rong

    2017-05-01

    We investigate the optical-response properties of a coherent-mechanical pumped optomechanical system (OMS) coupled to a Λ-type three-level atomic ensemble. Due to the optomechanical and the cavity-atom couplings, the optomechanically induced transparency (OMIT) and electromagnetically induced transparency (EIT) phenomena could both be observed from our proposal. In the presence of a coherent mechanical pump, we show that the OMIT behavior of the probe field exhibits a phase-dependent effect, leading to the switch from OMIT to optomechanically induced absorption or amplification, while the feature of EIT remains unchanged. The distinctly different effects of the mechanical pump on OMIT and EIT behavior assure us that the absorption (amplification) and transparency of the output probe field can be simultaneously observed. Moreover, a tunable switch from slow to fast light can also be realized by tuning the phase and amplitude of the mechanical pump. In particular, the presence of the atomic ensemble can further adjust the group delay, providing additional flexibility for achieving the tunable switch.

  18. Bacteremia during adenoidectomy: a comparison of suction diathermy adenoid ablation and adenoid curettage.

    LENUS (Irish Health Repository)

    Casserly, Paula

    2010-08-01

    Transient bacteremia is induced by adenoidectomy when the integrity of the nasopharyngeal membrane is broken. The aim of this study was to determine the incidence of bacteremia in patients undergoing adenoidectomy, to identify the causative organisms, and to compare the incidences of bacteremia between the two techniques suction diathermy and curettage.

  19. Demonstration of flexible multicasting and aggregation functionality for TWDM-PON

    Science.gov (United States)

    Chen, Yuanxiang; Li, Juhao; Zhu, Paikun; Zhu, Jinglong; Tian, Yu; Wu, Zhongying; Peng, Huangfa; Xu, Yongchi; Chen, Jingbiao; He, Yongqi; Chen, Zhangyuan

    2017-06-01

    The time- and wavelength-division multiplexed passive optical network (TWDM-PON) has been recognized as an attractive solution to provide broadband access for the next-generation networks. In this paper, we propose flexible service multicasting and aggregation functionality for TWDM-PON utilizing multiple-pump four-wave-mixing (FWM) and cyclic arrayed waveguide grating (AWG). With the proposed scheme, multiple TWDM-PON links share a single optical line terminal (OLT), which can greatly reduce the network deployment expense and achieve efficient network resource utilization by load balancing among different optical distribution networks (ODNs). The proposed scheme is compatible with existing TDM-PON infrastructure with fixed-wavelength OLT transmitter, thus smooth service upgrade can be achieved. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment with 10-Gb/s OOK and 10-Gb/s QPSK orthogonal frequency division multiplexing (OFDM) signal multicasting and aggregating to seven PON links. Compared with back-to-back (BTB) channel, the newly generated multicasting OOK signal and OFDM signal have power penalty of 1.6 dB and 2 dB at the BER of 10-3, respectively. For the aggregation of multiple channels, no obvious power penalty is observed. What is more, to verify the flexibility of the proposed scheme, we reconfigure the wavelength selective switch (WSS) and adjust the number of pumps to realize flexible multicasting functionality. One to three, one to seven, one to thirteen and one to twenty-one multicasting are achieved without modifying OLT structure.

  20. Numerical Calculation and Experiment of Coupled Dynamics of the Differential Velocity Vane Pump Driven by the Hybrid Higher-order Fourier Non-circular Gears

    Science.gov (United States)

    Xu, Gaohuan; Chen, Jianneng; Zhao, Huacheng

    2018-06-01

    The transmission systems of the differential velocity vane pumps (DVVP) have periodic vibrations under loads. And it is not easy to find the reason. In order to optimize the performance of the pump, the authors proposed DVVP driven by the hybrid Higher-order Fourier non-circular gears and tested it. There were also similar periodic vibrations and noises under loads. Taking into account this phenomenon, the paper proposes fluid mechanics and solid mechanics simulation methodology to analyze the coupling dynamics between fluid and transmission system and reveals the reason. The results show that the pump has the reverse drive phenomenon, which is that the blades drive the non-circular gears when the suction and discharge is alternating. The reverse drive phenomenon leads the sign of the shaft torque to be changed in positive and negative way. So the transmission system produces torsional vibrations. In order to confirm the simulation results, micro strains of the input shaft of the pump impeller are measured by the Wheatstone bridge and wireless sensor technology. The relationships between strain and torque are obtained by experimental calibration, and then the true torque of input shaft is calculated indirectly. The experimental results are consistent to the simulation results. It is proven that the periodic vibrations are mainly caused by fluid solid coupling, which leads to periodic torsional vibration of the transmission system.

  1. Investigation of Turbulent Tip Leakage Vortex in an Axial Water Jet Pump with Large Eddy Simulation

    Science.gov (United States)

    Hah, Chunill; Katz, Joseph

    2012-01-01

    Detailed steady and unsteady numerical studies were performed to investigate tip clearance flow in an axial water jet pump. The primary objective is to understand physics of unsteady tip clearance flow, unsteady tip leakage vortex, and cavitation inception in an axial water jet pump. Steady pressure field and resulting steady tip leakage vortex from a steady flow analysis do not seem to explain measured cavitation inception correctly. The measured flow field near the tip is unsteady and measured cavitation inception is highly transient. Flow visualization with cavitation bubbles shows that the leakage vortex is oscillating significantly and many intermittent vortex ropes are present between the suction side of the blade and the tip leakage core vortex. Although the flow field is highly transient, the overall flow structure is stable and a characteristic frequency seems to exist. To capture relevant flow physics as much as possible, a Reynolds-averaged Navier-Stokes (RANS) calculation and a Large Eddy Simulation (LES) were applied for the current investigation. The present study reveals that several vortices from the tip leakage vortex system cross the tip gap of the adjacent blade periodically. Sudden changes in local pressure field inside tip gap due to these vortices create vortex ropes. The instantaneous pressure filed inside the tip gap is drastically different from that of the steady flow simulation. Unsteady flow simulation which can calculate unsteady vortex motion is necessary to calculate cavitation inception accurately even at design flow condition in such a water jet pump.

  2. What can be done about corrosion in submersible pumps?

    Energy Technology Data Exchange (ETDEWEB)

    Minett, S.

    2000-09-01

    Useful advice and a survey of materials and techniques which can help counter corrosion risks in submersible pumps are provided. The greatest risk of corrosion is caused by sea water, hydrochloric acid, certain types of solvents, hydrogen sulphide, liquids with a high copper content, bases with a high pH value and certain liquids containing a mixture of acids. Counteractive strategies suggested include using a corrosion resistant material such as stainless steel, or other resistant coatings and materials for particular components that are exposed to high corrosion risks. Most submersible pumps are made of cast iron which should present no corrosion problems in normal domestic use. In mining and construction applications aluminum submersibles are common, which is resistant to a pH value of about 8. The use of stainless steel is recommended as the main material in submersible pumps when used for pumping acidic liquids, and when purity of the liquid pumped is of prime consideration. Coatings and anodes on conventional cast iron pumps are a less expensive and more flexible alternative against salt water corrosion. Among coatings epoxy coating is the most widely used. Zinc anodes are used in conjunction with epoxy coatings, which by setting up a micro current by contact with the cast iron prevent corrosion of areas of the cast iron that may be exposed as a result of post-production scratching. By being sacrificially corroded, the zinc anodes thus significantly extend the life of a coated pump. Impressed current from an external power source, is an effective, but more expensive alternative to the implanted anode method. Using resistant materials such as nitrile rubber, fluoro-carbon rubber, corrosion resistant cemented carbide, or chlorinated rubber for various components (rotating shaft seals, rubber 'O' rings, cable sheathing, etc) are other alternatives that may be depending on the application and the degree of exposure.

  3. Cyclosporin A levels in suction-blister fluid of patients with psoriasis treated systemically

    NARCIS (Netherlands)

    Meinardi, M. M.; van Eendenburg, J. P.; Oosting, J.; van Boxtel, C. J.; de Rie, M. A.; Bos, J. D.

    1990-01-01

    Oral cyclosporin A (CyA) is highly effective in the treatment of psoriasis. The long-term use is limited by dose-dependent side-effects, and the local concentration of CyA is a determining factor in treatment. The concentration of CyA in suction-blister fluid (SBF) and in whole blood was assessed

  4. In situ sampling of small volumes of soil solution using modified micro-suction cups

    NARCIS (Netherlands)

    Shen, Jianbo; Hoffland, E.

    2007-01-01

    Two modified designs of micro-pore-water samplers were tested for their capacity to collect unbiased soil solution samples containing zinc and citrate. The samplers had either ceramic or polyethersulfone (PES) suction cups. Laboratory tests of the micro-samplers were conducted using (a) standard

  5. A comparison of the disconnection technique with continuous bronchial suction for lung deflation when using the Arndt endobronchial blocker during video-assisted thoracoscopy: A randomised trial.

    Science.gov (United States)

    El-Tahan, Mohamed R

    2015-06-01

    The use of the Arndt endobronchial blocker has not gained widespread acceptance during video-assisted thoracoscopic surgery (VATS) because of its high cost and longer time to operative lung collapse especially in patients with chronic obstructive pulmonary disease (COPD). The use of a ventilator disconnection technique has been shown to produce a comparable degree of lung collapse when used with either a double-lumen tube or an Arndt endobronchial blocker. We hypothesised that the use of bronchial suction through the suction port of the endobronchial blocker would be associated with a comparable time to achieve optimum lung collapse as the disconnection technique. A randomised, double-blind study. Single university hospital. Fifty-eight patients with spontaneous pneumothorax scheduled for elective VATS using the Arndt endobronchial blocker for one-lung ventilation (OLV). Patients were randomly assigned to one of two groups (n = 29 per group) to deflate the operative lung with either disconnection of the endotracheal tube from the ventilator for 60 s prior to inflation of the endobronchial blocker or connection of a suction pressure of -30 cmH2O to the suction port of the endobronchial blocker through the barrel of a 1 ml syringe. The primary outcome was the time to total lung collapse. Secondary outcomes included surgeon rating of lung collapse, overall surgeon satisfaction, need for further fibreoptic bronchial suction manoeuvres and intraoperative hypoxaemia. The bronchial suction technique was associated with a significantly shorter time to total lung collapse than the disconnection method [93 (95% confidence interval, 95% CI 81.3 to 103.7) vs. 197 (95% CI 157.4 to 237) s respectively; P < 0.001]. Both the disconnection and bronchial suction groups had a comparable surgical rating of excellent lung collapse 40 min after the start of OLV (65.5 vs. 79.3%, respectively; P = 0.24), overall surgeon satisfaction [median (interquartile range, IQR) 9 (8 to 10) vs. 9 (8

  6. Smart Markets for Transferable Pumping Rights

    Science.gov (United States)

    Brozovic, N.; Young, R.

    2016-12-01

    While no national policy on groundwater use exists in the United States, local groundwater management is emerging across the country in response to concerns and conflicts over declining well yields, land subsidence, and the depletion of hydrologically connected surface waters. Management strategies include well drilling moratoria, pumping restrictions, and restrictions on the expansion of irrigated land. To provide flexibility to groundwater users, local regulatory authorities increasingly have begun to allow the transfer of groundwater rights as a cost-effective management tool. Markets can be a versatile risk management tool, helping communities to cope with scarcity, to meet goals for sustainability, and to grow resilient local economies. For example, active groundwater rights transfers exist in the High Plains region of the United States. Yet, several barriers to trade exist: high search costs for interested parties, complicated requirements for regulatory compliance, and reluctance to share sensitive financial information. Additionally, groundwater pumping leads to several kinds of spatial and intertemporal externalities such as stream depletion. Indeed, groundwater management schemes that reallocate water between alternate pumping locations are often explicitly designed to change the distribution and magnitude of pumping externalities. Reallocation may be designed to minimize unwanted impacts on third parties or to encourage trades that reduce the magnitude of externalities. We discuss how smart markets can deal with complex biophysical constraints while also encouraging active trading, therefore ensuring local goals for aquifer sustainability while growing local economies. Smart markets address these issues by providing a centralized hub for trading, automating the process of regulatory compliance by only matching buyers and sellers eligible to trade as specified in the regulations, and maintaining anonymous, confidential bidding.

  7. A retrospective study of the use of active suction wound drains in dogs and cats.

    Science.gov (United States)

    Bristow, P C; Halfacree, Z J; Baines, S J

    2015-05-01

    To report indications for use and complications associated with commonly used closed active suction wound drains in a large number of clinical cases. Retrospective review of medical case records (from 2004 to 2010) for dogs and cats that had a closed active suction drain placed into a wound. Only the four most common drain types were included: Mini Redovac®, Redovac®, Jackson Pratt® and Wound Evac®. Two hundred and fifty-three drains were placed in 33 cats and 195 dogs. Mini Redovac drains were used most frequently in cats (76 · 5%) and Redovac drains in dogs (54 · 3%). The infection rate for clean surgeries in dogs was 15 · 6% (unattainable in cats). Major complications occurred in four dogs; minor complications occurred in 12 drains in cats (35 · 3%), and in 74 drains in dogs (33 · 8%). There was no statistically significant association between the type of drain and complication rate for either species. Although closed active suction drains can be used with low risk of major complications, they lead to a high rate of infection in clean surgeries in dogs. It is recommended that such drains are kept in place for the shortest time possible and that strict asepsis is adhered to both during placement and management. © 2015 British Small Animal Veterinary Association.

  8. Determination of Matric Suction and Saturation Degree for Unsaturated Soils, Comparative Study - Numerical Method versus Analytical Method

    Science.gov (United States)

    Chiorean, Vasile-Florin

    2017-10-01

    Matric suction is a soil parameter which influences the behaviour of unsaturated soils in both terms of shear strength and permeability. It is a necessary aspect to know the variation of matric suction in unsaturated soil zone for solving geotechnical issues like unsaturated soil slopes stability or bearing capacity for unsaturated foundation ground. Mathematical expression of the dependency between soil moisture content and it’s matric suction (soil water characteristic curve) has a powerful character of nonlinearity. This paper presents two methods to determine the variation of matric suction along the depth included between groundwater level and soil level. First method is an analytical approach to emphasize one direction steady state unsaturated infiltration phenomenon that occurs between the groundwater level and the soil level. There were simulated three different situations in terms of border conditions: precipitations (inflow conditions on ground surface), evaporation (outflow conditions on ground surface), and perfect equilibrium (no flow on ground surface). Numerical method is finite element method used for steady state, two-dimensional, unsaturated infiltration calculus. Regarding boundary conditions there were simulated identical situations as in analytical approach. For both methods, was adopted the equation proposed by van Genuchten-Mualen (1980) for mathematical expression of soil water characteristic curve. Also for the unsaturated soil permeability prediction model was adopted the equation proposed by van Genuchten-Mualen. The fitting parameters of these models were adopted according to RETC 6.02 software in function of soil type. The analyses were performed in both methods for three major soil types: clay, silt and sand. For each soil type were concluded analyses for three situations in terms of border conditions applied on soil surface: inflow, outflow, and no flow. The obtained results are presented in order to highlight the differences

  9. Flexibility of Large-Scale Solar Heating Plant with Heat Pump and Thermal Energy Storage

    DEFF Research Database (Denmark)

    Luc, Katarzyna Marta; Heller, Alfred; Rode, Carsten

    2017-01-01

    to decrease biomass use in a district heating system. The paper focuses on the renewable energy-based district heating system in Marstal, Denmark, with heat produced in central solar heating plant, wood pellet boiler, heat pump and bio-oil boiler. The plant has been the object of research and developments...

  10. Set-up and Test Procedure for Suction Installation and Uninstallation of Bucket Foundation

    DEFF Research Database (Denmark)

    Koteras, Aleksandra Katarzyna

    This technical report describes the set-up and the test procedures for installation and uninstallation of medium-scale model of bucket foundation that can be performed in the geotechnical part of laboratory in Aalborg University. The installation of bucket foundation can be tested with the use of......) and loading frame used for those tests have been already used for axially static and cyclic loading of piles (Thomassen, 2015a) and for axially static and cyclic loading of bucket foundation (Vaitkunaite et al., 2015).......This technical report describes the set-up and the test procedures for installation and uninstallation of medium-scale model of bucket foundation that can be performed in the geotechnical part of laboratory in Aalborg University. The installation of bucket foundation can be tested with the use...... of suction under the bucket lid or by applying additional force through the hydraulic piston, forcing the bucket to penetrate into the soil. Tests for uninstallation are performed also with the use of water pressure, as a reverse process to the suction installation. Both installation and uninstallation tests...

  11. 75 FR 70112 - Medical Devices; General and Plastic Surgery Devices; Classification of Non-Powered Suction...

    Science.gov (United States)

    2010-11-17

    .... FDA-2010-N-0513] Medical Devices; General and Plastic Surgery Devices; Classification of Non-Powered... risks. Adverse tissue reaction Material degradation Improper function of suction apparatus (e.g., reflux.... Material degradation Section 8. Stability and Shelf Life. [[Page 70113

  12. Flexibility analysis of main primary heat transport system : Narora Atomic Power Project

    International Nuclear Information System (INIS)

    Rastogi, S.K.

    1975-01-01

    The paper presents flexibility analysis problem of main primary heat transport system and the approximate analysis that has been made to estimate the loads coming on major equipments. The primary heat transport system for Narora Atomic Power Project is adopting vertical steam generators and pumps equally divided on either side of the reactor with inter-connecting pipes and feeders. Since the system is mainly spring supported with movement of a few points in certain direction defined but no anchorage, it represents a good problem for flexibility analysis which can only be solved in one step by developing a good computer programme. (author)

  13. 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

  14. Efficacy of intermittent sub-glottic suctioning in prevention of ventilator-associated pneumonia- A preliminary study of 100 patients

    Directory of Open Access Journals (Sweden)

    M N Vijai

    2016-01-01

    Full Text Available Background and Aims: Oropharyngeal colonisation followed by aspiration of contaminated secretions is the major cause for ventilator-associated pneumonia (VAP. Pooled secretions present in the sub-glottic area above inflated endotracheal tube cuff may be aspirated into the lower airways. It was hypothesised that intermittent suctioning of sub-glottic secretions would prevent VAP. Methods: Group I (n = 50 patients were intubated with HiLo Evac™ endotracheal (ET tube with facility for sub-glottic suctioning, and Group II (n = 50 patients were intubated with HiLo Contour™ ET tube without such facility. In the Group I, sub-glottic suctioning was performed every 2 h. Incidence of VAP, mean ventilator days, Intensive Care Unit (ICU stay and mortality were compared. Qualitative variables were reported as percentages and were compared by Chi-square test or unpaired two-tailed, Fisher′s exact test, as appropriate, to analyse the significance of difference between the two groups. Results: The two groups were similar with respect to demographic characteristics. VAP was seen in 6% of patients in Group I and 22% of patients in Group II (P = 0.021. Both early- and late-onset VAPs were significantly reduced in Group I. Both ventilator days (8.0 vs. 6.45; P = 0.001 and ICU stay (8.33 vs. 6.33; P = 0.001 on the day of onset of VAP were significantly more in the Group I. Total ventilator days were significantly less (6.52 vs. 8.32; P = 0.006 with lower incidence of mortality (36% vs. 48%; P = 0.224 in the Group I. Conclusion: Intermittent sub-glottic suctioning reduces the incidence of VAP including late-onset VAP.

  15. Efficacy of intermittent sub-glottic suctioning in prevention of ventilator-associated pneumonia- A preliminary study of 100 patients.

    Science.gov (United States)

    Vijai, M N; Ravi, Parli R; Setlur, Rangaraj; Vardhan, Harsh

    2016-05-01

    Oropharyngeal colonisation followed by aspiration of contaminated secretions is the major cause for ventilator-associated pneumonia (VAP). Pooled secretions present in the sub-glottic area above inflated endotracheal tube cuff may be aspirated into the lower airways. It was hypothesised that intermittent suctioning of sub-glottic secretions would prevent VAP. Group I (n = 50) patients were intubated with HiLo Evac™ endotracheal (ET) tube with facility for sub-glottic suctioning, and Group II (n = 50) patients were intubated with HiLo Contour™ ET tube without such facility. In the Group I, sub-glottic suctioning was performed every 2 h. Incidence of VAP, mean ventilator days, Intensive Care Unit (ICU) stay and mortality were compared. Qualitative variables were reported as percentages and were compared by Chi-square test or unpaired two-tailed, Fisher's exact test, as appropriate, to analyse the significance of difference between the two groups. The two groups were similar with respect to demographic characteristics. VAP was seen in 6% of patients in Group I and 22% of patients in Group II (P = 0.021). Both early- and late-onset VAPs were significantly reduced in Group I. Both ventilator days (8.0 vs. 6.45; P = 0.001) and ICU stay (8.33 vs. 6.33; P = 0.001) on the day of onset of VAP were significantly more in the Group I. Total ventilator days were significantly less (6.52 vs. 8.32; P = 0.006) with lower incidence of mortality (36% vs. 48%; P = 0.224) in the Group I. Intermittent sub-glottic suctioning reduces the incidence of VAP including late-onset VAP.

  16. A Peristaltic Pump Integrated on a 100% Glass Microchip Using Computer Controlled Piezoelectric Actuators

    Directory of Open Access Journals (Sweden)

    Yo Tanaka

    2014-05-01

    Full Text Available Lab-on-a-chip technology is promising for the miniaturization of chemistry, biochemistry, and/or biology researchers looking to exploit the advantages of a microspace. To manipulate fluid on a microchip, on-chip pumps are indispensable. To date, there have been several types of on-chip pumps including pneumatic, electroactive, and magnetically driven. However these pumps introduce polymers, metals, and/or silicon to the microchip, and these materials have several disadvantages, including chemical or physical instability, or an inherent optical detection limit. To overcome/avoid these issues, glass has been one of the most commonly utilized materials for the production of multi-purpose integrated chemical systems. However, glass is very rigid, and it is difficult to incorporate pumps onto glass microchips. This paper reports the use of a very flexible, ultra-thin glass sheet (minimum thickness of a few micrometers to realize a pump installed on an entirely glass-based microchip. The pump is a peristaltic-type, composed of four serial valves sealing a cavity with two penetrate holes using ultra-thin glass sheet. By this pump, an on-chip circulating flow was demonstrated by directly observing fluid flow, visualized via polystyrene tracking particles. The flow rate was proportional to the pumping frequency, with a maximum flow rate of approximately 0.80 μL/min. This on-chip pump could likely be utilized in a wide range of applications which require the stability of a glass microchip.

  17. Stability analysis on the flow and heat transfer of nanofluid past a stretching/shrinking cylinder with suction effect

    Science.gov (United States)

    Bakar, Nor Ashikin Abu; Bachok, Norfifah; Arifin, Norihan Md.; Pop, Ioan

    2018-06-01

    The steady boundary layer flow over a stretching/shrinking cylinder with suction effect is numerically studied. Using a similarity transformations, the governing partial differential equations are transformed into a set of nonlinear differential equations and have been solved numerically using a bvp4c code in Matlab software. The nanofluid model used is taking into account the effects of Brownian motion and thermophoresis. The influences of the governing parameters namely the curvature parameter γ, mass suction parameter S, Brownian motion parameter Nb and thermophoresis parameter Nt on the flow, heat and mass transfers characteristics are presented graphically. The numerical results obtained for the skin friction coefficient, local Nusselt number and local Sherwood number are thoroughly determined and presented graphically for several values of the governing parameters. From our investigation, it is found that the non-unique (dual) solutions exist for a certain range of mass suction parameter. It is observed that as curvature parameter increases, the skin friction coefficient and heat transfer rate decrease, meanwhile the mass transfer rates increase. Moreover, the stability analysis showed that the first solution is linearly stable, while the second solution is linearly unstable.

  18. Heat Pumps in Private Residences used for Grid Balancing by Demand Response Methods

    DEFF Research Database (Denmark)

    Nielsen, Kirsten M.; Pedersen, Tom S.; Andersen, Palle

    2012-01-01

    Increased production of renewable energy as wind energy will give a fluctuating production which requires flexible energy storages. Heat capacity in single-family houses with electrical heating using heat pumps represents a storage which can be used to balance the electricity supply. It is assumed....... The minimization results in a power consumption schedule and a temperature schedule for each house. A number of control structures are described aiming to obtain this optimum by communicating references to either house temperature or heat pump power or by offering the consumer an hour by hour price. By simulation...... the schemes are compared by there ability to time shift consumption and to avoid consumer discomfort. Additionally the necessary information exchange for the schemes is discussed. Comparisons indicate that it is possible to use heat pump heated private houses to move power consumption within a time interval...

  19. Abstract flexibility description for virtual power plant scheduling

    OpenAIRE

    Fröhling, Judith

    2017-01-01

    In the ongoing paradigm shift of the energy market from big power plants to more and more small and decentralized power plants, virtual power plants (VPPs) play an important role. VPPs bundle the capacities of the small and decentralized resources (DER). Planing of VPP operation, that is also called scheduling, relies on the flexibilities of controllable DER in the VPP, e.g., combined heat and power plants (CHPs), heat pumps and batteries. The aim of this thesis is the development of an abstr...

  20. Simulation of flow structure in the suction pipe of a hydroturbine by integral characteristics

    DEFF Research Database (Denmark)

    Kuibin, P.A.; Okulov, Valery; Pylev, I.M.

    2006-01-01

    Within the framework of a model of a twisted flow of an inviscid incompressible liquid, we solve the problem of determining the frequency and amplitude of oscillations caused by the precession of a helical vortex core in the suction tube of a hydroturbine from the specified integral characteristics...

  1. 77 FR 25717 - Proposed Issuance of a General NPDES Permit for Small Suction Dredging

    Science.gov (United States)

    2012-05-01

    ...) General Permit (IDG-37-0000) to placer mining operations in Idaho for small suction dredges (intake nozzle... ENVIRONMENTAL PROTECTION AGENCY [FRL-9666-1] Proposed Issuance of a General NPDES Permit for Small... certifies ``will not, if promulgated, have a significant economic impact on a substantial number of small...

  2. LMFBR with booster pump in pumping loop

    International Nuclear Information System (INIS)

    Rubinstein, H.J.

    1975-01-01

    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

  3. Controls on shallow landslide initiation: Diverse hydrologic pathways, 3D failure geometries, and unsaturated soil suctions

    Science.gov (United States)

    Reid, Mark; Iverson, Richard; Brien, Dianne; Iverson, Neal; LaHusen, Richard; Logan, Matthew

    2017-04-01

    Shallow landslides and ensuing debris flows are a common hazard worldwide, yet forecasting their initiation at a specific site is challenging. These challenges arise, in part, from diverse near-surface hydrologic pathways under different wetting conditions, 3D failure geometries, and the effects of suction in partially saturated soils. Simplistic hydrologic models typically used for regional hazard assessment disregard these complexities. As an alterative to field studies where the effects of these governing factors can be difficult to isolate, we used the USGS debris-flow flume to conduct controlled, field-scale landslide initiation experiments. Using overhead sprinklers or groundwater injectors on the flume bed, we triggered failures using three different wetting conditions: groundwater inflow from below, prolonged moderate-intensity precipitation, and bursts of high-intensity precipitation. Failures occurred in 6 m3 (0.65-m thick and 2-m wide) prisms of loamy sand on a 31° slope; these field-scale failures enabled realistic incorporation of nonlinear scale-dependent effects such as soil suction. During the experiments, we monitored soil deformation, variably saturated pore pressures, and moisture changes using ˜50 sensors sampling at 20 Hz. From ancillary laboratory tests, we determined shear strength, saturated hydraulic conductivities, and unsaturated moisture retention characteristics. The three different wetting conditions noted above led to different hydrologic pathways and influenced instrumental responses and failure timing. During groundwater injection, pore-water pressures increased from the bed of the flume upwards into the sediment, whereas prolonged moderate infiltration wet the sediment from the ground surface downward. In both cases, pore pressures acting on the impending failure surface slowly rose until abrupt failure. In contrast, a burst of intense sprinkling caused rapid failure without precursory development of widespread positive pore

  4. A flexible and low cost experimental stand for air source heat pump for Smart Buildings

    DEFF Research Database (Denmark)

    Crăciun, Vasile S.; Bojesen, Carsten; Blarke, Morten

    2012-01-01

    Energy systems are faced with the challenges of reducing dependency on fossil fuels, while handling increasing penetration levels of intermittent renewables such as wind and solar power. At the same time, the efficient consumption of energy is vital for avoiding the impacts from increasing fuel...... prices. A significant part of this challenge may be dealt with in the way space heating, space cooling, and domestic hot water production which is provided to residential and commercial buildings. Air source heat pumps (ASHP) are widely used conversion technologies for providing building thermal energy...... services; cooling, heating, and water heating. ASHP does not have a constant temperature for the primary source like: soil, ground water, or surface water heat pumps. In result, laboratory experiments and tests are faced by the problem of having to handle a wide range of conditions under which...

  5. Short-snouted toothless ichthyosaur from China suggests Late Triassic diversification of suction feeding ichthyosaurs.

    Directory of Open Access Journals (Sweden)

    P Martin Sander

    Full Text Available BACKGROUND: Ichthyosaurs were an important group of Mesozoic marine reptiles and existed from the Early Triassic to the early Late Cretaceous. Despite a great diversity in body shapes and feeding adaptations, all share greatly enlarged eyes, an elongated rostrum with numerous conical teeth, and a streamlined body. METHODOLOGY/PRINCIPAL FINDINGS: Based on new material from China and the restudy of Shastasaurus pacificus, we here reinterpret the classical large-bodied Late Triassic ichthyosaur genus Shastasaurus to differ greatly from the standard ichthyosaurian body plan, indicating much greater morphological diversity and range of feeding adaptations in ichthyosaurs than previously recognized. Phylogenetic analysis indicates a monophyletic clade consisting of the giant Shonisaurus sikanniensis, Guanlingsaurus liangae, and Shastasaurus pacificus to which the genus name Shastasaurus is applied. Shastasaurus liangae comb. nov. is from the Late Triassic (Carnian Xiaowa Formation of Guizhou Province, southwestern China. The species combines a diminutive head with an entirely toothless and greatly reduced snout. The species also has by far the highest vertebral count among ichthyosaurs (86 presacral vertebrae and >110 caudal vertebrae, a count that is also very high for tetrapods in general. A reduced toothless snout and a diminutive head is also apparently present in the giant S. sikanniensis and presumably in S. pacificus. CONCLUSIONS/SIGNIFICANCE: In analogy to many modern odontocetes, Shastasaurus is interpreted as a specialized suction feeder on unshelled cephalopods and fish, suggesting a unique but widespread Late Triassic diversification of toothless, suction-feeding ichthyosaurs. Suction feeding has not been hypothesized for any of the other diverse marine reptiles of the Mesozoic before, but in Shastasaurus may be linked to the Late Triassic minimum in atmospheric oxygen.

  6. Active Flow Control in a Radial Vaned Diffuser for Surge Margin Improvement: A Multislot Suction Strategy

    Directory of Open Access Journals (Sweden)

    Aurélien Marsan

    2017-01-01

    Full Text Available This work is the final step of a research project that aims at evaluating the possibility of delaying the surge of a centrifugal compressor stage using a boundary-layer suction technique. It is based on Reynolds-Averaged Navier-Stokes numerical simulations. Boundary-layer suction is applied within the radial vaned diffuser. Previous work has shown the necessity to take into account the unsteady behavior of the flow when designing the active flow control technique. In this paper, a multislot strategy is designed according to the characteristics of the unsteady pressure field. Its implementation results in a significant increase of the stable operating range predicted by the unsteady RANS numerical model. A hub-corner separation still exists further downstream in the diffuser passage but does not compromise the stability of the compressor stage.

  7. Stall margin improvement of an axial flow fan with end wall injection and suction; Hekimen fukidashi suidashi ni yoru han'yo jikuryu sofuki no shissoku kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, K.; Kuroda, H.; Obata, S.; Chimura, O. [National Defense Academy, Kanagawa (Japan)

    1999-06-25

    The experimental studies are conducted to reveal the mechanism of stall margin improvement of an axial flow fan by injection or suction from the end wall. In case of injection, the largest improvement is obtained by the injection at about 0. 14 {approx} 0 .21 times axial chord length downstream from leading edge. The reason for large improvement is that stall vortex, shed intermittent separation vortex and tip leakage vortex are dissipated by this injection, and also that this blowing suppresses the separation of boundary layer. In case of suction, the largest improvement is found for the suction from the end wall near leading edge. The amplitude of periodic static pressure after stall inception becomes smaller in comparison with injection cases. These effects are increased with the increase of suction flow rate, because the discharge of the vortex occurs more easily. On the other hand, the suction from the upstream of leading edge reduces the axial velocity near rotor tip, and then it induces stall. Also we tried to visualize the tip region flow, The suppression mechanism is discussed based on the visualization. The suppression of stall is successfully photographed. (author)

  8. Selectively Plasmon-Enhanced Second-Harmonic Generation from Monolayer Tungsten Diselenide on Flexible Substrates

    KAUST Repository

    Wang, Zhuo

    2018-01-04

    Monolayer two-dimensional transition metal dichalcogenides (2D TMDCs) exhibit promising characteristics in miniaturized nonlinear optical frequency converters, due to their inversion asymmetry and large second-order nonlinear susceptibility. However, these materials usually have a very short light interaction lengths with the pump laser because they are atomically thin, such that second-harmonic generation (SHG) is generally inefficient. In this paper, we fabricate a judiciously structured 150-nm-thick planar surface consisting of monolayer tungsten diselenide and sub-20-nm-wide gold trenches on flexible substrates, reporting ~7000-fold SHG enhancement without peak broadening or background in the spectra as compared to WSe2 on as-grown sapphire substrates. Our proof-of-concept experiment yields effective second-order nonlinear susceptibility of 2.1 × 104 pm/V. Three orders of magnitude enhancement is maintained with pump wavelength ranging from 800 nm to 900 nm, breaking the limitation of narrow pump wavelength range for cavity-enhanced SHG. In addition, SHG amplitude can be dynamically controlled via selective excitation of the lateral gap plasmon by rotating the laser polarization. Such fully open, flat and ultrathin profile enables a great variety of functional samples with high SHG from one patterned silicon substrate, favoring scalable production of nonlinear converters. The surface accessibility also enables integration with other optical components for information processing in an ultrathin and flexible form.

  9. Selectively Plasmon-Enhanced Second-Harmonic Generation from Monolayer Tungsten Diselenide on Flexible Substrates

    KAUST Repository

    Wang, Zhuo; Dong, Zhaogang; Zhu, Hai; Jin, Lei; Chiu, Ming-Hui; Li, Lain-Jong; Xu, Qing-Hua; Eda, Goki; Maier, Stefan A.; Wee, Andrew T. S.; Qiu, Cheng-Wei; Yang, Joel K.W.

    2018-01-01

    Monolayer two-dimensional transition metal dichalcogenides (2D TMDCs) exhibit promising characteristics in miniaturized nonlinear optical frequency converters, due to their inversion asymmetry and large second-order nonlinear susceptibility. However, these materials usually have a very short light interaction lengths with the pump laser because they are atomically thin, such that second-harmonic generation (SHG) is generally inefficient. In this paper, we fabricate a judiciously structured 150-nm-thick planar surface consisting of monolayer tungsten diselenide and sub-20-nm-wide gold trenches on flexible substrates, reporting ~7000-fold SHG enhancement without peak broadening or background in the spectra as compared to WSe2 on as-grown sapphire substrates. Our proof-of-concept experiment yields effective second-order nonlinear susceptibility of 2.1 × 104 pm/V. Three orders of magnitude enhancement is maintained with pump wavelength ranging from 800 nm to 900 nm, breaking the limitation of narrow pump wavelength range for cavity-enhanced SHG. In addition, SHG amplitude can be dynamically controlled via selective excitation of the lateral gap plasmon by rotating the laser polarization. Such fully open, flat and ultrathin profile enables a great variety of functional samples with high SHG from one patterned silicon substrate, favoring scalable production of nonlinear converters. The surface accessibility also enables integration with other optical components for information processing in an ultrathin and flexible form.

  10. The pumping of hydrogen and helium by sputter-ion pumps

    International Nuclear Information System (INIS)

    Welch, K.M.; Pate, D.J.; Todd, R.J.

    1992-01-01

    The pumping of hydrogen in diode and triode sputter-ion pumps is discussed. The type of cathode material used in these pumps is shown to have a significant impact on the effectiveness with which hydrogen is pumped. Examples of this include data for pumps with aluminum and titanium-alloy cathodes. Diode pumps with aluminum cathodes are shown to be no more effective in the pumping of hydrogen than in the pumping of helium. The use of titanium or titanium alloy anodes is also shown to measurably impact on the speed of these pumps at.very low pressures. This stems from the fact that hydrogen is x10 6 more soluble in titanium than in stainless steel. Hydrogen becomes resident in the anodes because of fast neutral burial. Lastly, quantitative data are given for the He speeds and capacities of both noble and conventional diode and triode pumps. The effectiveness of various pump regeneration procedures, subsequent to the pumping of He, is reported.These included bakeout and N 2 glow discharge cleaning. The comparative desorption of He with the subsequent pumping of N 2 is reported on. The N 2 speed of these pumps was used as the benchmark for defining the size of the pumps vs. their respective He speeds

  11. Equilibrium configuration for a high current pumped divertor

    International Nuclear Information System (INIS)

    Lazzaro, E.; Keegan, B.

    1989-01-01

    A realistic design of a pumped divertor plasma configuration to be fitted to the JET vessel can be obtained as a compromise among various geometrical, physical and technical constraints. The possibility of reaching a satisfactory solution has been analysed for plasmas up to 6 MA. Optimisation of the plasma coupling to the RF antennae requires a largely asymmetric distribution of ampere turns in the PF coils and some mechanical flexibility. The calculations presented were carried out using the specially developed JET equilibrium and configuration analysis codes. (U.K.)

  12. Liquid metals pumping

    International Nuclear Information System (INIS)

    Le Frere, J.P.

    1984-01-01

    Pumps used to pump liquid metals depend on the liquid metal and on the type of application concerned. One deals more particularly with electromagnetic pumps, the main pumps used with mechanical pumps. To pump sodium in the nuclear field, these two types of pumps are used; the pumps of different circuits of Super Phenix are presented and described [fr

  13. Free Convection from a Semi-Infinite Vertical Plate with Discontinuous Blowing or Suction.

    Science.gov (United States)

    1981-03-01

    SCHIESSR UNCLASSIFIED; EhEllllEllEE EE[E]hEEEIllIEllhlEEIl EEEEEIIIEEEEI EEEIIIIIIIIII EIIIEIIEEEEII EEEIIIIIIIIIIE LVEL NAVAL POSTGRADUATE SCHOOL Monterey...the unsteady free convective flow past a simi-infinite porous plate with constant suction were studied through mathematical analysis by Soundalgekar...boundary-layers and; therefore, will often indicate a preferred method of analytical solution. Although there are several possible mathematical techniques

  14. A numerically research on energy loss evaluation in a centrifugal pump system based on local entropy production method

    Directory of Open Access Journals (Sweden)

    Hou Hucan

    2017-01-01

    Full Text Available Inspired by wide application of the second law of thermodynamics to flow and heat transfer devices, local entropy production analysis method was creatively introduced into energy assessment system of centrifugal water pump. Based on Reynolds stress turbulent model and energy equation model, the steady numerical simulation of the whole flow passage of one IS centrifugal pump was carried out. The local entropy production terms were calculated by user defined functions, mainly including wall entropy production, turbulent entropy production, and viscous entropy production. The numerical results indicated that the irreversible energy loss calculated by the local entropy production method agreed well with that calculated by the traditional method but with some deviations which were probably caused by high rotatability and high curvature of impeller and volute. The wall entropy production and turbulent entropy production took up large part of the whole entropy production about 48.61% and 47.91%, respectively, which indicated that wall friction and turbulent fluctuation were the major factors in affecting irreversible energy loss. Meanwhile, the entropy production rate distribution was discussed and compared with turbulent kinetic energy dissipation rate distribution, it showed that turbulent entropy production rate increased sharply at the near wall regions and both distributed more uniformly. The blade region in leading edge near suction side, trailing edge and volute tongue were the main regions to generate irreversible exergy loss. This research broadens a completely new view in evaluating energy loss and further optimizes pump using entropy production minimization.

  15. Flexible and stable heat energy recovery from municipal wastewater treatment plants using a fixed-inverter hybrid heat pump system

    International Nuclear Information System (INIS)

    Chae, Kyu-Jung; Ren, Xianghao

    2016-01-01

    Highlights: • Specially designed fixed-inverter hybrid heat pump system was developed. • Hybrid operation performed better at part loads than single inverter operation. • The applied heat pump can work stably over a wide range of heat load variations. • Heat energy potential of treated effluent was better than influent. • The heat pump’s COP from the field test was 4.06 for heating and 3.64 for cooling. - Abstract: Among many options to improve energy self-sufficiency in sewage treatment plants, heat extraction using a heat pump holds great promise, since wastewater contains considerable amounts of thermal energy. The actual heat energy demand at municipal wastewater treatment plants (WWTPs) varies widely with time; however, the heat pumps typically installed in WWTPs are of the on/off controlled fixed-speed type, thus mostly run intermittently at severe part-load conditions with poor efficiency. To solve this mismatch, a specially designed, fixed-inverter hybrid heat pump system incorporating a fixed-speed compressor and an inverter-driven, variable-speed compressor was developed and tested in a real WWTP. In this hybrid configuration, to improve load response and energy efficiency, the base-heat load was covered by the fixed-speed compressor consuming relatively less energy than the variable-speed type at nominal power, and the remaining varying load was handled by the inverter compressor which exhibits a high load-match function while consuming relatively greater energy. The heat pump system developed reliably extracted heat from the treated effluent as a heat source for heating and cooling purposes throughout the year, and actively responded to the load changes with a high measured coefficient of performance (COP) of 4.06 for heating and 3.64 for cooling. Moreover, this hybrid operation yielded a performance up to 15.04% better on part loads than the single inverter operation, suggesting its effectiveness for improving annual energy saving when

  16. Continuously pumping and reactivating gas pump

    International Nuclear Information System (INIS)

    Batzer, T.H.; Call, W.R.

    1984-01-01

    Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped

  17. Continuously pumping and reactivating gas pump

    Science.gov (United States)

    Batzer, Thomas H.; Call, Wayne R.

    1984-01-01

    Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

  18. Application of the time dependent suction to free convection laminar flow in the presence of transverse magnetic field

    International Nuclear Information System (INIS)

    Agrawal, H.L.; Ram, P.C.

    1980-01-01

    The laminar unsteady free convection and heat transfer of an electrically conducting fluid past a porous vertical flat plate in the presence of uniform transverse magnetic field is investigated when the free stream velocity and suction at the plate are oscillatory functions of time, viscous dissipation term and Joul's dissipation term have been neglected at low velocity. Expressions for velocity and temperature distributions have been obtained in the non-dimensional forms and the skin-friction has been calculated. The skin-friction decreases by increasing Hartmann number. The suction is applied to check the growth of the boundary layer. This study is likely to have bearing on the problem of boundary layer control and transpiration cooling. (author)

  19. Effect of pump limiter throat on pumping efficiency

    International Nuclear Information System (INIS)

    Ghendrih, P.; Grosman, A.; Samain, A.; Capes, H.; Morera, J.P.

    1988-01-01

    The necessary control of plasma edge density has led to the development of pump limiters to achieve this task. On Tore Supra, where a large part of the program is devoted to plasma edge studies, two types of such density control apparatus have been implemented, a set of pump limiters and the pumps associated to the ergodic divertor (magnetically assisted pump limiters). Generally two different kinds of pump limiters can be used, those with a throat which drives the plasma from the open edge plasma (SOL) to the neutralizer plate, and those without or with a very short throat. We are interested here in this aspect of the pump limiter concept, i.e. on the throat effect on neutral density build-up in the vicinity of the pumping plates (and hence on pumping efficieny). The underlying idea of this throat effect can be readily understood; indeed while the neutral capture in pump limiters without throats is only a ballistic effect, on expects the plasma to improve the efficiency of pump-limiters via plasma-neutral-sidewall interactions in the throat. This problem has been studied both numerically and analytically. The paper is divided as follows. In section 2, we describe the basic features of pump-limiters which are modelized by the numerical code Cezanne. Section 3 is devoted to the throat length effect considering in particular the neutral density profile in the throat and the neutral density buil-up as a function of the throat lenght. In section 4, we show that the plugging effect occurs for reasonnable values of throat lengths. An analytical value of the plugging length is discussed and compared to the values obtained numerically

  20. The use of suction blisters to measure sunscreen protection against UVR-induced DNA damage.

    Science.gov (United States)

    Josse, Gwendal; Douki, Thierry; Le Digabel, Jimmy; Gravier, Eleonore; Questel, Emmanuel

    2018-02-01

    The formation of DNA photoproducts caused by solar UVR exposure needs to be investigated in-vivo and in particular in order to assess sunscreens' level of protection against solar genotoxicity. The study's purposes were: i) to evaluate if the roof of suction blisters is an appropriate sampling method for measuring photoproducts, and ii) to measure in-vivo sunscreen protection against cyclobutane pyrimidine dimers. Skin areas on the interior forearms of eight healthy volunteers were exposed in-vivo to 2 MED of simulated solar radiation (SSR) and to 15 MED on a sunscreen protected area. After irradiation, six suction blisters were induced and the blister roofs were collected. Analysis of SSR-induced CPDs was performed by two independent methods: a chromatography coupled to mass spectroscopy (HPLC-MS/MS) approach and a 3D-imaging of CPD immunostaining by multiphoton microscopy on floating epidermal sheets. HPLC-MS/MS analyses showed that SSR-unexposed skin presented no CPD dimers, whereas 2 MED SSR-exposed skin showed a significant number of TT-CPD. The sunscreen covered skin exposed to 15 MED appeared highly protected from DNA damage, as the amount of CPD-dimers remained below the detection limit. The multiphoton-immunostaining analysis consistently showed that no CPD staining was observed on the non-SSR-exposed skin. A significant increase of CPD staining intensity and number of CPD-positive cells were observed on the 2 MED SSR-exposed skin. Sunscreen protected skin presented a very low staining intensity and the number of CPD-positive cells remained very close to non-SSR-exposed skin. This study showed that suction blister samples are very appropriate for measuring CPD dimers in-vivo, and that sunscreens provide high protection against UVR-induced DNA damage. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. 78 FR 14722 - Airworthiness Directives; The Boeing Company Airplanes

    Science.gov (United States)

    2013-03-07

    ... (JASC)/Air Transport Association (ATA) of America Code 2800, Aircraft Fuel System. (e) Unsafe Condition... repetitive operational tests of the engine fuel suction feed of the fuel system, and other related testing if... total loss of boost pump pressure of the fuel feed system, followed by loss of fuel system suction feed...

  2. 77 FR 41934 - Airworthiness Directives; The Boeing Company Airplanes

    Science.gov (United States)

    2012-07-17

    ... Transport Association (ATA) of America Code 2800, Aircraft Fuel System. (e) Unsafe Condition This AD was... operational tests of the engine fuel suction feed of the fuel system, and other related testing if necessary... loss of boost pump pressure of the fuel feed system, followed by loss of fuel system suction feed...

  3. Gage for gas flow measurement especially in gas-suction pipes

    International Nuclear Information System (INIS)

    Renner, K.; Stegmanns, W.

    1978-01-01

    The gage utilizes the differential pressure given by a differential pressure producer to generate, in a bypass, a partial gas flow measured by means of a direct-reading anemometer of windmill type. The partial gas flow is generated between pressure pick-up openings in the gas-suction pipe in front of a venturi insert and pressure pick-up openings at the bottleneck of the venturi insert. The reading of the anemometer is proportional to the main gas flow and independent of the variables of state and the properties of the gases to be measured. (RW) [de

  4. Entropy Generation in a Rotating Couette Flow with Suction/Injection

    Directory of Open Access Journals (Sweden)

    S. Das

    2015-05-01

    Full Text Available The present paper is concerned with an analytical study of entropy generation in viscous incompressible Couette flow with suction/injection in a rotating frame of reference. One of the plate is held at rest and the other one moves with an uniform velocity.The flow induced by the moving plate. An exact solution of governing equations has been obtained in closed form. The entropy generation number and the Bejan number are also obtained. The influences of each of the governing parameters on velocity, temperature, entropy generation and Bejan number are discussed with the help of graphs.

  5. Reflection Phenomena in Underground Pumped Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Elena Pummer

    2018-04-01

    Full Text Available Energy storage through hydropower leads to free surface water waves in the connected reservoirs. The reason for this is the movement of water between reservoirs at different elevations, which is necessary for electrical energy storage. Currently, the expansion of renewable energies requires the development of fast and flexible energy storage systems, of which classical pumped storage plants are the only technically proven and cost-effective technology and are the most used. Instead of classical pumped storage plants, where reservoirs are located on the surface, underground pumped storage plants with subsurface reservoirs could be an alternative. They are independent of topography and have a low surface area requirement. This can be a great advantage for energy storage expansion in case of environmental issues, residents’ concerns and an unusable terrain surface. However, the reservoirs of underground pumped storage plants differ in design from classical ones for stability and space reasons. The hydraulic design is essential to ensure their satisfactory hydraulic performance. The paper presents a hybrid model study, which is defined here as a combination of physical and numerical modelling to use the advantages and to compensate for the disadvantages of the respective methods. It shows the analysis of waves in ventilated underground reservoir systems with a great length to height ratio, considering new operational aspects from energy supply systems with a great percentage of renewable energies. The multifaceted and narrow design of the reservoirs leads to complex free surface flows; for example, undular and breaking bores arise. The results show excessive wave heights through wave reflections, caused by the impermeable reservoir boundaries. Hence, their knowledge is essential for a successful operational and constructive design of the reservoirs.

  6. Analgesic efficacy of lidocaine for suction-assisted lipectomy with tumescent technique under general anesthesia: a randomized, double-masked, controlled trial.

    Science.gov (United States)

    Danilla, Stefan; Fontbona, Montserrat; de Valdés, Victoria Diaz; Dagnino, Bruno; Sorolla, Juan Pablo; Israel, Guillermo; Searle, Susana; Norambuena, Hernán; Cabello, Rodrigo

    2013-08-01

    Suction-assisted lipectomy is one of the most common procedures performed in plastic surgery. To minimize blood loss and to obtain adequate analgesia, a liquid solution is infiltrated into the subcutaneous plane before suction. The objective of this study was to determine whether the use of lidocaine in the infiltration solution reduces postoperative pain. A prospective, randomized, double-masked, clinical trial was designed. Each side of patients' body zones to be treated with suction-assisted lipectomy was randomized to receive infiltration solution with or without lidocaine. Treatment allocation was performed using computer-generated random numbers in permuted blocks of eight. Pain was assessed using the visual analogue scale and registered 1, 6, 12, 18, and 24 hours after the procedure. The trial was stopped after a first interim analysis. The use of lidocaine in the dilute solution reduced pain by 0.5 point on the visual analogue scale (95 percent CI, 0.3 to 0.8; p<0.001). The effect was independent of the suctioned body zone (p=0.756), and lasted until 18 hours after surgery. Its analgesic effect was lost at the 24-hour postoperative control. Pain increased an average of 0.018 point on the visual analogue scale per hour (95 percent CI, 0.001 to 0.036; p=0.043). The use of lidocaine in the infiltration solution is effective in postoperative pain control until 18 hours after surgery. Nevertheless, its clinical effect is limited and clinically irrelevant, and therefore it is no longer used by the authors. Therapeutic, I.

  7. Study of Hydrogen Pumping through Condensed Argon in Cryogenic pump

    International Nuclear Information System (INIS)

    Jadeja, K A; Bhatt, S B

    2012-01-01

    In ultra high vacuum (UHV) range, hydrogen is a dominant residual gas in vacuum chamber. Hydrogen, being light gas, pumping of hydrogen in this vacuum range is limited with widely used UHV pumps, viz. turbo molecular pump and cryogenic pump. Pre condensed argon layers in cryogenic pump create porous structure on the surface of the pump, which traps hydrogen gas at a temperature less than 20° K. Additional argon gas injection in the cryogenic pump, at lowest temperature, generates multiple layers of condensed argon as a porous frost with 10 to 100 A° diameters pores, which increase the pumping capacity of hydrogen gas. This pumping mechanism of hydrogen is more effective, to pump more hydrogen gas in UHV range applicable in accelerator, space simulation etc. and where hydrogen is used as fuel gas like tokamak. For this experiment, the cryogenic pump with a closed loop refrigerator using helium gas is used to produce the minimum cryogenic temperature as ∼ 14° K. In this paper, effect of cryosorption of hydrogen is presented with different levels of argon gas and hydrogen gas in cryogenic pump chamber.

  8. Flexible Electrostatic Technologies for Capture and Handling, Phase 1

    Science.gov (United States)

    Bryan, Thomas

    2015-01-01

    Fundamental to many of NASA's in-space transportation missions is the capture and handling of various objects and vehicles in various orbits for servicing, debris disposal, sample retrieval, and assembly without the benefit of sufficient grapple fixtures and docking ports. To perform similar material handling tasks on Earth, pincher grippers, suction grippers, or magnetic chucks are used, but are unable to reliably grip aluminum and composite spacecraft, insulation, radiators, solar arrays, or extra-terrestrial objects in the vacuum of outer space without dedicated handles in the right places. The electronic Flexible Electrostatic Technologies for space Capture and Handling (FETCH) will enable reliable and compliant gripping (soft dock) of practically any object in various orbits or surfaces without dedicated mechanical features, very low impact capture, and built-in proximity sensing without any conventional actuators. Originally developed to handle semiconductor and glass wafers during vacuum chamber processing without contamination, the normal rigid wafer handling chucks are replaced with thin metal foil segments laminated in flexible insulation driven by commercial off-the-shelf solid state, high-voltage power supplies. Preliminary testing in NASA Marshall Space Flight Center's (MSFC's) Flat Floor Robotics Lab demonstrated compliant alignment and gripping with a full-sized, 150-lb microsat mockup and translation before a clean release with a flip of a switch. The flexible electrostatic gripper pads can be adapted to various space applications with different sizes, shapes, and foil electrode layouts even with openings through the gripper pads for addition of guidance sensors or injection of permanent adhesives. With gripping forces estimated between 0.5 and 2.5 lb/in2 or 70-300 lb/ft2 of surface contact, the FETCH can turn on and off rapidly and repeatedly to enable sample handling, soft docking, in-space assembly, precision relocation, and surface translation

  9. Savannah River Site reactor hardware design modification study

    International Nuclear Information System (INIS)

    Fisher, J.E.

    1990-01-01

    A study was undertaken to assess the merits of proposed design modifications to the Savannah River Site (SRS) reactors. The evaluation was based on the responses calculated by the RELAP5 systems code to double-ended guillotine break loss-of-coolant-accidents (DEGB LOCAs). The three concepts evaluated were (a) elevated plenum inlet piping with a guard vessel and clamshell enclosures, (b) closure of both rotovalves in the affected loop, and (c) closure of the pump suction valve in the affected loop. Each concept included a fast reactor shutdown (to 65% power in 100 ms) and a 2-s ac pump trip. System recovery potential was evaluated for break locations at the pump suction, the pump discharge, and the plenum inlet. The code version used was RELAP5/MOD2.5 version 3d3, a preliminary version of RELAP5/MOD3. The model was a three-dimensional representation of the K-Reactor water plenum and moderator tank. It included explicit representations of all six loops, which were based on the configuration of L-Reactor. A combination of features is recommended to ensure liquid inventory recovery for all break locations. Valve closure design performance for a break location in the short section of piping between the reactor concrete shield and the pump suction valve would benefit from the clamshell enclosing that section of piping. 7 refs., 10 figs., 2 tabs

  10. Machine concept optimization for pumped-storage plants through combined dispatch simulation for wholesale and reserve markets

    International Nuclear Information System (INIS)

    Engels, Klaus; Harasta, Michaela; Braitsch, Werner; Moser, Albert; Schaefer, Andreas

    2012-01-01

    In Germany's energy markets of today, pumped-storage power plants offer excellent business opportunities due to their outstanding flexibility. However, the energy-economic simulation of pumped-storage plants, which is necessary to base the investment decision on a sound business case, is a highly complex matter since the plant's capacity must be optimized in a given plant portfolio and between two relevant markets: the scheduled wholesale and the reserve market. This mathematical optimization problem becomes even more complex when the question is raised as to which type of machine should be used for a pumped-storage new build option. For the first time, it has been proven possible to simulate the optimum dispatch of different pumped-storage machine concepts within two relevant markets - the scheduled wholesale and the reserve market - thereby greatly supporting the investment decision process. The methodology and findings of a cooperation study between E.ON and RWTH Aachen University in respect of the German pumped-storage extension project 'Waldeck 2+' are described, showing the latest development in dispatch simulation for generation portfolios. (authors)

  11. Fixed-speed and Variable-speed Pumped Storage Dispatch Model in Power Systems with High Renewable Penetration

    Science.gov (United States)

    Yuan, Bo; Zong, Jin; Xu, Zhicheng

    2018-06-01

    According to different operating characteristics of pumped storage fixed speed unit and variable speed unit, a joint dispatching model of pumped storage unit and other types of units based on mixed integer linear optimization is constructed. The model takes into account the operating conditions, reservoir capacity, cycle type and other pumped storage unit constraints, but also consider the frequent start and stop and the stability of the operation of the unit caused by the loss. Using the Cplex solver to solve the model, the empirical example of the provincial power grid shows that the model can effectively arrange the pumping storage speed and the dispatching operation of the variable speed unit under the precondition of economic life of the unit, and give full play to the function of peak shaving and accommodating new energy. Because of its more flexible regulation characteristics of power generation and pumping conditions, the variable speed unit can better improve the operating conditions of other units in the system and promote the new energy dissipation.

  12. Fixed-speed and Variable-speed Pumped Storage Dispatch Model in Power Systems with High Renewable Penetration

    Directory of Open Access Journals (Sweden)

    Yuan Bo

    2018-01-01

    Full Text Available According to different operating characteristics of pumped storage fixed speed unit and variable speed unit, a joint dispatching model of pumped storage unit and other types of units based on mixed integer linear optimization is constructed. The model takes into account the operating conditions, reservoir capacity, cycle type and other pumped storage unit constraints, but also consider the frequent start and stop and the stability of the operation of the unit caused by the loss. Using the Cplex solver to solve the model, the empirical example of the provincial power grid shows that the model can effectively arrange the pumping storage speed and the dispatching operation of the variable speed unit under the precondition of economic life of the unit, and give full play to the function of peak shaving and accommodating new energy. Because of its more flexible regulation characteristics of power generation and pumping conditions, the variable speed unit can better improve the operating conditions of other units in the system and promote the new energy dissipation.

  13. A Prospective Randomized Study Comparing Manual and Wall Suction in the Performance of Bronchoalveolar Lavage.

    Science.gov (United States)

    Seijo, Luis M; Flandes, Javier; Somiedo, Maria V; Naya, Alba; Manjón, Josefina; Álvarez, Susana; Fernández-Navamuel, Iker

    2016-01-01

    Bronchoalveolar lavage (BAL) may be performed using a hand-held syringe or wall suction. The aim was to study BAL volume and diagnostic yields based on BAL technique. A total of 220 consecutive patients undergoing BAL at our center were included. Manual aspiration was performed in 115 patients (group 1), and wall suction (<50 mm Hg of negative pressure) was used in 105 patients (group 2). All bronchoscopies were performed under conscious sedation applying topical anesthesia with lidocaine. Three 50-ml sterile saline aliquots were instilled in all patients. The mean total amount of fluid recovered was 67 ± 20 ml in group 1 and 55 ± 22 ml in group 2 (p < 0.001). More patients in the manual aspiration group met American Thoracic Society criteria (recovery of ≥30% of instilled fluid) for an optimal BAL (81 vs. 59%; p < 0.001). The quantity of recovered fluid was also related to BAL location (p < 0.001) and radiologic findings (p = 0.002). Forty-eight (22%) BALs were diagnostic (23 in group 1 and 25 in group 2), including 37 positive bacterial cultures, 6 positive stains for Pneumocystis, and 5 cases of malignancy. No statistically significant difference in diagnostic yield was observed between the two groups. A BAL diagnosis was more likely in patients with certain radiologic (p = 0.033) and endoscopic findings (p = 0.001). When taking into account all bronchoscopic techniques performed during the procedure (e.g. biopsies, brushing, etc.), bronchoscopy was diagnostic in 37% of patients. Manual aspiration is superior to wall suction during BAL yielding a larger quantity of aspirate. Diagnostic yields are similar for both techniques. © 2016 S. Karger AG, Basel.

  14. Dry vacuum pumps

    International Nuclear Information System (INIS)

    Sibuet, R

    2008-01-01

    For decades and for ultimate pressure below 1 mbar, oil-sealed Rotary Vane Pumps have been the most popular solution for a wide range of vacuum applications. In the late 80ies, Semiconductor Industry has initiated the development of the first dry roughing pumps. Today SC applications are only using dry pumps and dry pumping packages. Since that time, pumps manufacturers have developed dry vacuum pumps technologies in order to make them attractive for other applications. The trend to replace lubricated pumps by dry pumps is now spreading over many other market segments. For the Semiconductor Industry, it has been quite easy to understand the benefits of dry pumps, in terms of Cost of Ownership, process contamination and up-time. In this paper, Technology of Dry pumps, its application in R and D/industries, merits over conventional pumps and future growth scope will be discussed

  15. Off-Pump Versus On-Pump Coronary Artery Bypass Grafting

    DEFF Research Database (Denmark)

    Møller, Christian H; Steinbrüchel, Daniel A

    2014-01-01

    Coronary artery bypass grafting (CABG) remains the preferred treatment in patients with complex coronary artery disease. However, whether the procedure should be performed with or without the use of cardiopulmonary bypass, referred to as off-pump and on-pump CABG, is still up for debate....... Intuitively, avoidance of cardiopulmonary bypass seems beneficial as the systemic inflammatory response from extracorporeal circulation is omitted, but no single randomized trial has been able to prove off-pump CABG superior to on-pump CABG as regards the hard outcomes death, stroke or myocardial infarction....... In contrast, off-pump CABG is technically more challenging and may be associated with increased risk of incomplete revascularization. The purpose of the review is to summarize the current literature comparing outcomes of off-pump versus on-pump coronary artery bypass surgery....

  16. Destroyer Engineered Operating Cycle (DDEOC), System Maintenance Analysis DDG-37 Class, Salt Water Circulating System SMA 37-106-256, Review of Experience

    Science.gov (United States)

    1978-07-01

    horizontally mounted, single-end suction, single- stage centrifugal pumps. The rotating elements are mounted on the shaft of the driving motor, and the pump...annual open-and-inspect requirement for MIP E-17/296-21, MRC 21 A14V A. Industrial Facility Improvements -- None IMA Improvements -- None Intergrated ...Circulating Pump, Warren Pumps, Inc., NAVSHIPS 347-3146, January 1959. 4. Technical Manual - Horizontal Close-Co!;pled Pumps Sea (Salt) Water

  17. BLOCKAGE 2.5 reference manual

    International Nuclear Information System (INIS)

    Shaffer, C.J.; Brideau, J.; Rao, D.V.; Bernahl, W.

    1996-12-01

    The BLOCKAGE 2.5 code was developed by the US Nuclear Regulatory Commission (NRC) as a tool to evaluate license compliance regarding the design of suction strainers for emergency core cooling system (ECCS) pumps in boiling water reactors (BWR) as required by NRC Bulletin 96-03, ''Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors''. Science and Engineering Associates, Inc. (SEA) and Software Edge, Inc. (SE) developed this PC-based code. The instructions to effectively use this code to evaluate the potential of debris to sufficiently block a pump suction strainer such that a pump could lose NPSH margin was documented in a User's Manual (NRC, NUREG/CR-6370). The Reference Manual contains additional information that supports the use of BLOCKAGE 2.5. It contains descriptions of the analytical models contained in the code, programmer guides illustrating the structure of the code, and summaries of coding verification and model validation exercises that were performed to ensure that the analytical models were correctly coded and applicable to the evaluation of BWR pump suction strainers. The BLOCKAGE code was developed by SEA and programmed in FORTRAN as a code that can be executed from the DOS level on a PC. A graphical users interface (GUI) was then developed by SEA to make BLOCKAGE easier to use and to provide graphical output capability. The GUI was programmed in the C language. The user has the option of executing BLOCKAGE 2.5 with the GUI or from the DOS level and the Users Manual provides instruction for both methods of execution

  18. Low temperature distillation

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, J N; Postel, C

    1929-04-09

    To recover gas, oil tars, and coked residues by low temperature distillation from bituminous coals, lignites, oil shales, and the like, the raw material is fed from a hopper into a rotary retort which is zonally heated, the temperature being greatest at the discharge end. The material is heated first to a relatively low temperature, thereby removing the moisture and lighter volatiles which are withdrawn through a pipe by the suction of a pump, while the higher boiling point volatiles and fixed gases are withdrawn by suction through an outlet from the higher temperature zone. The vapors withdrawn from the opposite ends of the retort pass through separate vapor lines and condensers, and the suction in each end of the retort, caused by the pumps, is controlled by valves, which also control the location of the neutral point in the retort formed by said suction. Air and inert gas may be introduced into the retort from pipe and stack respectively through a pipe, and steam may be admitted into the high temperature zone through a pipe.

  19. Dispersion of suspended material from an operating sand suction dredge in the Øresund (Denmark)

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Møhlenberg, F.

    1981-01-01

    The concentration of suspended material in the immediate vicinity of an operating sand suction dredge in the Oresund was 3-5000mg/l. Concentrations > 100 mg/l were restricted to a downstream distance of .apprx. 150m and ambient levels were reached within .apprx. 1 km of the dredge. The natural...

  20. Capillary Suction Time. Operational Control Tests for Wastewater Treatment Facilities. Instructor's Manual [and] Student Workbook.

    Science.gov (United States)

    Wooley, John F.

    Capillary suction time is time required for the liquid phase of a treated sludge to travel through 1 centimeter of media (blotter or filter paper). Designed for individuals who have completed National Pollutant Discharge Elimination System (NPDES) level 1 laboratory training skills, this module provides waste water treatment plant operators with…

  1. Heat pump technology

    CERN Document Server

    Von Cube, Hans Ludwig; Goodall, E G A

    2013-01-01

    Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

  2. Liquid metal pump

    Science.gov (United States)

    Pennell, William E.

    1982-01-01

    The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair.

  3. Liquid metal pump

    International Nuclear Information System (INIS)

    Pennell, W.E.

    1982-01-01

    The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair

  4. Potential risk for bacterial contamination in conventional reused ventilator systems and disposable closed ventilator-suction systems.

    Science.gov (United States)

    Li, Ya-Chi; Lin, Hui-Ling; Liao, Fang-Chun; Wang, Sing-Siang; Chang, Hsiu-Chu; Hsu, Hung-Fu; Chen, Sue-Hsien; Wan, Gwo-Hwa

    2018-01-01

    Few studies have investigated the difference in bacterial contamination between conventional reused ventilator systems and disposable closed ventilator-suction systems. The aim of this study was to investigate the bacterial contamination rates of the reused and disposable ventilator systems, and the association between system disconnection and bacterial contamination of ventilator systems. The enrolled intubated and mechanically ventilated patients used a conventional reused ventilator system and a disposable closed ventilator-suction system, respectively, for a week; specimens were then collected from the ventilator circuit systems to evaluate human and environmental bacterial contamination. The sputum specimens from patients were also analyzed in this study. The detection rate of bacteria in the conventional reused ventilator system was substantially higher than that in the disposable ventilator system. The inspiratory and expiratory limbs of the disposable closed ventilator-suction system had higher bacterial concentrations than the conventional reused ventilator system. The bacterial concentration in the heated humidifier of the reused ventilator system was significantly higher than that in the disposable ventilator system. Positive associations existed among the bacterial concentrations at different locations in the reused and disposable ventilator systems, respectively. The predominant bacteria identified in the reused and disposable ventilator systems included Acinetobacter spp., Bacillus cereus, Elizabethkingia spp., Pseudomonas spp., and Stenotrophomonas (Xan) maltophilia. Both the reused and disposable ventilator systems had high bacterial contamination rates after one week of use. Disconnection of the ventilator systems should be avoided during system operation to decrease the risks of environmental pollution and human exposure, especially for the disposable ventilator system. ClinicalTrials.gov PRS / NCT03359148.

  5. Hemodynamic response to exercise and head-up tilt of patients implanted with a rotary blood pump: a computational modeling study.

    Science.gov (United States)

    Lim, Einly; Salamonsen, Robert Francis; Mansouri, Mahdi; Gaddum, Nicholas; Mason, David Glen; Timms, Daniel L; Stevens, Michael Charles; Fraser, John; Akmeliawati, Rini; Lovell, Nigel Hamilton

    2015-02-01

    The present study investigates the response of implantable rotary blood pump (IRBP)-assisted patients to exercise and head-up tilt (HUT), as well as the effect of alterations in the model parameter values on this response, using validated numerical models. Furthermore, we comparatively evaluate the performance of a number of previously proposed physiologically responsive controllers, including constant speed, constant flow pulsatility index (PI), constant average pressure difference between the aorta and the left atrium, constant average differential pump pressure, constant ratio between mean pump flow and pump flow pulsatility (ratioP I or linear Starling-like control), as well as constant left atrial pressure ( P l a ¯ ) control, with regard to their ability to increase cardiac output during exercise while maintaining circulatory stability upon HUT. Although native cardiac output increases automatically during exercise, increasing pump speed was able to further improve total cardiac output and reduce elevated filling pressures. At the same time, reduced venous return associated with upright posture was not shown to induce left ventricular (LV) suction. Although P l a ¯ control outperformed other control modes in its ability to increase cardiac output during exercise, it caused a fall in the mean arterial pressure upon HUT, which may cause postural hypotension or patient discomfort. To the contrary, maintaining constant average pressure difference between the aorta and the left atrium demonstrated superior performance in both exercise and HUT scenarios. Due to their strong dependence on the pump operating point, PI and ratioPI control performed poorly during exercise and HUT. Our simulation results also highlighted the importance of the baroreflex mechanism in determining the response of the IRBP-assisted patients to exercise and postural changes, where desensitized reflex response attenuated the percentage increase in cardiac output during exercise and

  6. 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

  7. The role of heat pump technologies in the design of future sustainable energy systems

    DEFF Research Database (Denmark)

    Blarke, Morten Boje; Lund, Henrik

    2005-01-01

    source results in an 8% cost reduction. Furthermore, the operational analysis shows that when a large-scale heat pump is integrated with an existing CHP unit, the projected spot market situation in Nord Pool, which reflects a growing share of wind power and heat-bound power generation electricity......In this paper, it is shown that in support of its ability to improve the overall economic cost-effectiveness and flexibility of the Danish energy system, the financially feasible integration of large-scale heat pumps with existing CHP units, is critically sensitive to the operational mode...... of the heat pump vis-à-vis the operational coefficient of performance (COP), which is set by the temperature level of the heat source. When using only ambient air as the heat source, the total heat production costs increases by about 10%, while the partial use of condensed flue gas from the CHP unit as a heat...

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

    OpenAIRE

    Li, Tao; Zhang, Weiming; Jiang, Ming; Li, Zhengyang

    2013-01-01

    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. Re...

  9. 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

  10. Numerical simulation of effects of a non-ionized fluid injection and suction on the MHD flow in a circular channel

    International Nuclear Information System (INIS)

    Rahimi Eosboee, M.; Pourmahmoud, N.; Mirzaie, I.; Mohajeri Khameneh, P.; Majidyfar, S.

    2012-01-01

    Control of a fluid flow velocity profile by injection and suction of a non-ionized fluid in presence of a uniform steady magnetic field has important technical applications. In this paper, the unsteady incompressible and viscous conducting fluid flow has been investigated in a circular channel. The channel walls are assumed to be non-conducting and porous. They are subjected to a uniform steady magnetic field which is perpendicular to the axis of channel, then and suction and injection are applied at the walls. The well known equations of Magnetohydrodynamics are governed to the motion of an electrically conducting fluid flow that is subjected to magnetic field. The numerical solution is carried out by finite difference approach. The results of present numerical simulation shown that the flow injection and suction through the wall can be controlled effectively, the main flow in channel especially in industrial purposes. The results are obtained for different values of the injected and sucked non-ionized flow rate and the effect of Hartman number on the velocity profile is investigated. Finally, a good agreement is seen between the presented results and the corresponding data of finite element method.

  11. Thermal analysis of hybrid single-phase, two-phase and heat pump thermal control system (TCS) for future spacecraft

    International Nuclear Information System (INIS)

    Lee, S.H.; Mudawar, I.; Hasan, Mohammad M.

    2016-01-01

    Highlights: • Hybrid Thermal Control System (H-TCS) is proposed for future spacecraft. • Thermodynamic performance of H-TCS is examined for different space missions. • Operational modes including single-phase, two-phase and heat pump are explored. • R134a is deemed most appropriate working fluid. - Abstract: An urgent need presently exists to develop a new class of versatile spacecraft capable of conducting different types of missions and enduring varying gravitational and temperature environments, including Lunar, Martian and Near Earth Object (NEOs). This study concerns the spacecraft's Thermal Control System (TCS), which tackles heat acquisition, especially from crew and avionics, heat transport, and ultimate heat rejection by radiation. The primary goal of the study is to explore the design and thermal performance of a Hybrid Thermal Control System (H-TCS) that would satisfy the diverse thermal requirements of the different space missions. The H-TCS must endure both ‘cold’ and ‘hot’ environments, reduce weight and size, and enhance thermodynamic performance. Four different operational modes are considered: single-phase, two-phase, basic heat pump and heat pump with liquid-side, suction-side heat exchanger. A thermodynamic trade study is conducted for six different working fluids to assess important performance parameters including mass flow rate of the working fluid, maximum pressure, radiator area, compressor/pump work, and coefficient of performance (COP). R134a is determined to be most suitable based on its ability to provide a balanced compromise between reducing flow rate and maintaining low system pressure, and a moderate coefficient of performance (COP); this fluid is also both nontoxic and nonflammable, and features zero ozone depletion potential (ODP) and low global warming potential (GWP). It is shown how specific mission stages dictate which mode of operation is most suitable, and this information is used to size the radiator for the

  12. Preload-based Starling-like control of rotary blood pumps: An in-vitro evaluation.

    Directory of Open Access Journals (Sweden)

    Mahdi Mansouri

    Full Text Available Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs are used to provide mechanical circulatory support. To address the preload insensitivity of the constant speed controller (CSC used in conventional LVADs, we developed a preload-based Starling-like controller (SLC. The SLC emulates the Starling law of the heart to maintain mean pump flow ([Formula: see text] with respect to mean left ventricular end diastolic pressure (PLVEDm as the feedback signal. The SLC and CSC were compared using a mock circulation loop to assess their capacity to increase cardiac output during mild exercise while avoiding ventricular suction (marked by a negative PLVEDm and maintaining circulatory stability during blood loss and severe reductions in left ventricular contractility (LVC. The root mean squared hemodynamic deviation (RMSHD metric was used to assess the clinical acceptability of each controller based on pre-defined hemodynamic limits. We also compared the in-silico results from our previously published paper with our in-vitro outcomes. In the exercise simulation, the SLC increased [Formula: see text] by 37%, compared to only 17% with the CSC. During blood loss, the SLC maintained a better safety margin against left ventricular suction with PLVEDm of 2.7 mmHg compared to -0.1 mmHg for CSC. A transition to reduced LVC resulted in decreased mean arterial pressure (MAP and [Formula: see text] with CSC, whilst the SLC maintained MAP and [Formula: see text]. The results were associated with a much lower RMSHD value with SLC (70.3% compared to CSC (225.5%, demonstrating improved capacity of the SLC to compensate for the varying cardiac demand during profound circulatory changes. In-vitro and in-silico results demonstrated similar trends to the simulated changes in patient state however the magnitude of hemodynamic changes were different, thus justifying the progression to in-vitro evaluation.

  13. Synchronous dual-wavelength pulse generation in coaxial pumping scheme and its application in terahertz difference frequency generation

    Science.gov (United States)

    Liu, Yang; Zhong, Kai; Mei, Jialin; Jin, Shuo; Ge, Meng; Xu, Degang; Yao, Jianquan

    2018-02-01

    A compact and flexible dual-wavelength laser with combined two laser crystals (a-cut and c-cut Nd:YLF) as the gain media under coaxially laser-diode (LD) end-pumping configuration was demonstrated and μW-level THz wave was generated based on difference frequency generation (DFG) in a GaSe crystal. The dynamics of coaxial pumping dualwavelength laser was theoretically investigated, showing that the power ratio and pulse interval for both wavelengths could be tuned by balancing the gains at both wavelengths via tuning pump focal position. Synchronized orthogonal 1047/1053 nm laser pulses were obtained and optimal power ratio was realized with the total output power of 2.92W at 5 kHz pumped by 10-W LD power. With an 8-mm-long GaSe crystal, 0.93 μW THz wave at 1.64 THz (182 μm) was generated. Such coaxially LD end-pumped lasers can be extended to various combinations of neodymium doped laser media to produce different THz wavelengths for costless and portable applications.

  14. Analysis of the Storage Capacity in an Aggregated Heat Pump Portfolio

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Mølgaard; Andersen, Palle; Pedersen, Tom Søndergård

    2015-01-01

    Energy storages connected to the power grid will be of great importance in the near future. A pilot project has investigated more than 100 single family houses with heat pumps all connected to the internet. The houses have large heat capacities and it is possible to move energy consumption to sui...... (scheduling) algorithm. The properties of this scheduling are investigated in the paper especially the flexibility and ability to trade on the intra-day regulating market is in focus....

  15. Penis Pump

    Science.gov (United States)

    ... your appointment might be less involved. Choosing a penis pump Some penis pumps are available without a ... it doesn't get caught in the ring. Penis pumps for penis enlargement Many advertisements in magazines ...

  16. Pumping characteristics of sputter ion pump (SIP) and titanium sublimation pump (TSP) combination

    International Nuclear Information System (INIS)

    Ratnakala, K.C.; Patel, R.J.; Bhavsar, S.T.; Pandiyar, M.L.; Ramamurthi, S.S.

    1995-01-01

    For achieving hydrocarbon free, clean ultra high vacuum, SIP-TSP combination is one of the ideal choice for pumping. For the SRS facility in Centre for Advanced Technology (CAT), we are utilising this combination, enmass. For this purpose, two modules of these combination set-ups are assembled, one with the TSP as an integral part of SIP and the other, with TSP as a separate pump mounted on the top of SIP. The pump bodies were vacuum degassed at 700 degC at 10 -5 mbar for 3 hrs. An ultimate vacuum of 3 x 10 -11 mbar was achieved, after a bake-out at 250 degC for 4 hrs, followed by continuous SIP pumping for 48 hrs, with two TSP flashing at approximately 10 hrs interval. The pump-down patterns as well as the pressure-rise patterns are studied. (author). 2 refs., 5 figs

  17. The efficiency analysis on solar energy auxiliary soil source heat pump heating in cold region%严寒地区太阳能辅助土壤源热泵供热经济性分析

    Institute of Scientific and Technical Information of China (English)

    王杨洋

    2016-01-01

    To solve the suction and discharge heat imbalance problems in soil source heat pump system long running in cold region,this paper put forward the solar assisted soil source heat pump system,and compared the efficiency of this plan with traditional central heating system,pointed out that the solar assisted soil source heat pump system in service life cycle had good energy conservation and environmental protection benefits.%为解决严寒地区土壤源热泵系统长期运行出现吸排热量失衡的问题,提出了太阳能辅助土壤源热泵系统方案,并将该方案与传统集中供热系统方案的经济性作了对比,指出太阳能辅助土壤源热泵系统在使用寿命周期内具有良好的节能环保效益。

  18. Potential Energy Flexibility for a Hot-Water Based Heating System in Smart Buildings Via Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Ahmed, Awadelrahman M. A.; Zong, Yi; Mihet-Popa, Lucian

    2017-01-01

    This paper studies the potential of shifting the heating energy consumption in a residential building to low price periods based on varying electricity price signals suing Economic Model Predictive Control strategy. The investigated heating system consists of a heat pump incorporated with a hot...... water tank as active thermal energy storage, where two optimization problems are integrated together to optimize both the heat pump electricity consumption and the building heating consumption. A sensitivity analysis for the system flexibility is examined. The results revealed that the proposed...

  19. Electromechanical performance analysis of inflated dielectric elastomer membrane for micro pump applications

    Science.gov (United States)

    Saini, Abhishek; Ahmad, Dilshad; Patra, Karali

    2016-04-01

    Dielectric elastomers have received a great deal of attention recently as potential materials for many new types of sensors, actuators and future energy generators. When subjected to high electric field, dielectric elastomer membrane sandwiched between compliant electrodes undergoes large deformation with a fast response speed. Moreover, dielectric elastomers have high specific energy density, toughness, flexibility and shape processability. Therefore, dielectric elastomer membranes have gained importance to be applied as micro pumps for microfluidics and biomedical applications. This work intends to extend the electromechanical performance analysis of inflated dielectric elastomer membranes to be applied as micro pumps. Mechanical burst test and cyclic tests were performed to investigate the mechanical breakdown and hysteresis loss of the dielectric membrane, respectively. Varying high electric field was applied on the inflated membrane under different static pressure to determine the electromechanical behavior and nonplanar actuation of the membrane. These tests were repeated for membranes with different pre-stretch values. Results show that pre-stretching improves the electromechanical performance of the inflated membrane. The present work will help to select suitable parameters for designing micro pumps using dielectric elastomer membrane. However this material lacks durability in operation.This issue also needs to be investigated further for realizing practical micro pumps.

  20. 76 FR 34192 - Commercial and Industrial Pumps

    Science.gov (United States)

    2011-06-13

    ... a specific speed below approximately 90 (4,500). Those having double- suction impellers usually have... three methods: (1) Reciprocating action of plungers, pistons, bellows or diaphragms; (2) Rotary action...