Design, in-sodium testing and performance evaluation of annular linear induction pump for a sodium cooled fast reactor

International Nuclear Information System (INIS)

Nashine, B.K.; Rao, B.P.C.

2014-01-01

Highlights: • Derivation of applicable design equations. • Design of an annular induction pump based on these equations. • Testing of the designed pump in a sodium test facility. • Performance evaluation of the designed pump. - Abstract: Annular linear induction pumps (ALIPs) are used for pumping electrically conducting liquid metals. These pumps find wide application in fast reactors since the coolant in fast reactors is liquid sodium which a good conductor of electricity. The design of these pumps is usually done using equivalent circuit approach in combination with numerical simulation models. The equivalent circuit of ALIP is similar to that of an induction motor. This paper presents the derivation of equivalent circuit parameters using first principle approach. Sodium testing of designed ALIP using the equivalent circuit approach is also described and experimental results of the testing are presented. Comparison between experimental and analytical calculations has also been carried out. Some of the reasons for variation have also been listed in this paper

Operating states of PFBR-primary sodium pump

International Nuclear Information System (INIS)

Sreedharan, K.V.; Rao, A.S.L.K.; Raju, C.; Kale, R.D.

1994-01-01

The proposed 500 MWe Prototype Fast Breeder Reactor (PFBR), the design of which is in progress at the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam will be equipped with four centrifugal sodium pumps each in its primary and secondary circuits. This paper discusses the various operating states of the primary pumps viz. (i) normal steady state (ii) transient state operation. The paper also discusses the safe limits on the pump operating speed and a few design basis incidents. (author). 1 ref., 2 figs., 3 tabs

Single-phase sodium pump model for LMFBR thermal-hydraulic analysis

International Nuclear Information System (INIS)

Madni, I.K.; Cazzoli, E.G.; Agrawal, A.K.

1979-01-01

A single-phase, homologous pump model has been developed for simulation of safety-related transients in LMFBR systems. Pump characteristics are modeled by homologous head and torque relations encompassing all regimes of operation. These relations were derived from independent model test results with a centrifugal pump of specific speed equal to 35 (SI units) or 1800 (gpm units), and are used to analyze the steady-state and transient behavior of sodium pumps in a number of LMFBR plants. Characteristic coefficients for the polynomials in all operational regimes are provided in a tabular form. The speed and flow dependence of head is included through solutions of the impeller and coolant dynamic equations. Results show the model to yield excellent agreement with experimental data in sodium for the FFTF prototype pump, and with vendor calculations for the CRBR pump. A sample pipe rupture calculation is also performed to demonstrate the necessity for modeling the complete pump characteristics

The Effects of Altered Membrane Cholesterol Levels on Sodium Pump Activity in Subclinical Hypothyroidism

Directory of Open Access Journals (Sweden)

Suparna Roy

2017-02-01

Full Text Available BackgroundMetabolic dysfunctions characteristic of overt hypothyroidism (OH start at the early stage of subclinical hypothyroidism (SCH. Na+/K+-ATPase (the sodium pump is a transmembrane enzyme that plays a vital role in cellular activities in combination with membrane lipids. We evaluated the effects of early changes in thyroid hormone and membrane cholesterol on sodium pump activity in SCH and OH patients.MethodsIn 32 SCH patients, 35 OH patients, and 34 euthyroid patients, sodium pump activity and cholesterol levels in red blood cell membranes were measured. Serum thyroxine (T4 and thyroid stimulating hormone (TSH levels were measured using enzyme-linked immunosorbent assays. Differences in their mean values were analysed using post hoc analysis of variance. We assessed the dependence of the sodium pump on other metabolites by multiple regression analysis.ResultsSodium pump activity and membrane cholesterol were lower in both hypothyroid groups than in control group, OH group exhibiting lower values than SCH group. In SCH group, sodium pump activity showed a significant direct dependence on membrane cholesterol with an inverse relationship with serum TSH levels. In OH group, sodium pump activity depended directly on membrane cholesterol and serum T4 levels. No dependence on serum cholesterol was observed in either case.ConclusionDespite the presence of elevated serum cholesterol in hypothyroidism, membrane cholesterol contributed significantly to maintain sodium pump activity in the cells. A critical reduction in membrane cholesterol levels heralds compromised enzyme activity, even in the early stage of hypothyroidism, and this can be predicted by elevated TSH levels alone, without any evident clinical manifestations.

Downregulation of surface sodium pumps by endocytosis during meiotic maturation of Xenopus laevis oocytes

International Nuclear Information System (INIS)

Schmalzing, G.; Eckard, P.; Kroener, S.P.; Passow, H.

1990-01-01

During meiotic maturation, plasma membranes of Xenopus laevis oocytes completely lose the capacity to transport Na and K and to bind ouabain. To explore whether the downregulation might be due to an internalization of the sodium pump molecules, the intracellular binding of ouabain was determined. Selective permeabilization of the plasma membrane of mature oocytes (eggs) by digitonin almost failed to disclose ouabain binding sites. However, when the eggs were additionally treated with 0.02% sodium dodecyl sulfate (SDS) to permeabilize inner membranes, all sodium pumps present before maturation were recovered. Phosphorylation by [gamma-32P]ATP combined with SDS-polyacrylamide gel electrophoresis (PAGE) and autoradiography showed that sodium pumps were greatly reduced in isolated plasma membranes of eggs. According to sucrose gradient fractionation, maturation induced a shift of sodium pumps from the plasma membrane fraction to membranes of lower buoyant density with a protein composition different from that of the plasma membrane. Endocytosed sodium pumps identified on the sucrose gradient from [3H]ouabain bound to the cell surface before maturation could be phosphorylated with inorganic [32P]phosphate. The findings suggest that downregulation of sodium pumps during maturation is brought about by translocation of surface sodium pumps to an intracellular compartment, presumably endosomes. This contrasts the mechanism of downregulation of Na-dependent cotransport systems, the activities of which are reduced as a consequence of a maturation-induced depolarization of the membrane without a removal of the corresponding transporter from the plasma membrane

Sodium-sodium intermediate heat exchangers design problems

International Nuclear Information System (INIS)

Chandramohan, R.

1975-01-01

This paper deals briefly with the calculation methods adapted, in working-out the stresses due to fluid pressures (normal as well as transient), weights, piping-reactions, vibration in the tube-bundle and also the thermal stresses during normal and transient conditions, for the mechanical design of intermediate heat-exchanger. The thermal stress evaluation of the tube-sheet is given particular emphasis. A brief outline of the design problems connected with the Na-Na exchangers of large size sodium cooled fast reactor plants is also given. (author)

Advanced intermediate temperature sodium copper chloride battery

Science.gov (United States)

Yang, Li-Ping; Liu, Xiao-Min; Zhang, Yi-Wei; Yang, Hui; Shen, Xiao-Dong

2014-12-01

Sodium metal chloride batteries, also called as ZEBRA batteries, possess many merits such as low cost, high energy density and high safety, but their high operation temperature (270-350 °C) may cause several issues and limit their applications. Therefore, decreasing the operation temperature is of great importance in order to broaden their usage. Using a room temperature ionic liquid (RTIL) catholyte composed of sodium chloride buffered 1-ethyl-3-methylimidazolium chloride-aluminum chloride and a dense β″-aluminates solid electrolyte film with 500 micron thickness, we report an intermediate temperature sodium copper chloride battery which can be operated at only 150 °C, therefore alleviating the corrosion issues, improving the material compatibilities and reducing the operating complexities associated with the conventional ZEBRA batteries. The RTIL presents a high ionic conductivity (0.247 S cm-1) at 150 °C and a wide electrochemical window (-2.6 to 2.18 vs. Al3+/Al). With the discharge plateau at 2.64 V toward sodium and the specific capacity of 285 mAh g-1, this intermediate temperature battery exhibits an energy density (750 mWh g-1) comparable to the conventional ZEBRA batteries (728-785 mWh g-1) and superior to commercialized Li-ion batteries (550-680 mWh g-1), making it very attractive for renewable energy integration and other grid related applications.

Resonant photopumping of a neon lasant plasma by a sodium pump plasma

International Nuclear Information System (INIS)

Young, F.C.; Apruzese, J.P.; Burkhalter, P.G.; Cooperstein, G.; Davis, J.; Mosher, D.; Ottinger, P.F.; Scherrer, V.E.; Stephanakis, S.J.; Mehlman, C.; Welch, B.L.

1988-01-01

Resonant photopumping of heliumlike neon by helium like sodium is being investigated to extend this pumping technique to the soft x-ray region. In the Na-pump/Ne-lasant system, the 1s 2 -1s2p 1 P 1 line of Na X at 11.0027 A differs by 2 parts in 10 4 from the 1s 2 -1s 4 p 1 P 1 line of Ne 1X at 11.0003 A. This wavelength difference corresponds to about one Doppler width at the sodium plasma temperatures (200-500 eV) required for strong Na X pump radiation. Sodium line radiation of sufficient power irradiating a properly prepared neon plasma will cause overpopulation of the Ne 1X n = 4 singlet level leading to lasing in the 4-3, 4-2, and possibly 3-2 singlet transitions. Experimentally, the current pulse from the NRL Gamble-II generator is used to produce side-by-side z-pinch plasmas of sodium fluoride (NaF) and neon. The discharges are viewed radially with x-ray diagnostics including time-integrated pinhole cameras, time-resolved x-ray diodes, and a time-integrated curved-crystal spectrograph. Measurements of the neon plasma indicate that a discharge current of about 200 kA is required to produce a neon lasant with a dominant heliumlike ground-state population. For fluorescence experiments, appropriate neon lasant conditions (density of about 10 18 cm -3 and temperature of 50-100 eV) must be produced at the time of the intense sodium pump-line radiation. Fluorescence is demonstrated by observing enhancement of the 4-1 line (He-γ) from the neon plasma relative to the 3-1 line (He-γ) when the neon is pumped by sodium. An increase in this γ-to-β ratio of 25% has been observed when the sodium pump radiation is present. The results of recent experiments are reported, and their implications for future experiments are discussed

Sodium flow rate measurement method of annular linear induction pump

International Nuclear Information System (INIS)

Araseki, Hideo

2011-01-01

This report describes a method for measuring sodium flow rate of annular linear induction pumps arranged in parallel and its verification result obtained through an experiment and a numerical analysis. In the method, the leaked magnetic field is measured with measuring coils at the stator end on the outlet side and is correlated with the sodium flow rate. The experimental data and the numerical result indicate that the leaked magnetic field at the stator edge keeps almost constant when the sodium flow rate changes and that the leaked magnetic field change arising from the flow rate change is small compared with the overall leaked magnetic field. It is shown that the correlation between the leaked magnetic field and the sodium flow rate is almost linear due to this feature of the leaked magnetic field, which indicates the applicability of the method to small-scale annular linear induction pumps. (author)

Thirteen pump-probe resonances of the sodium D1 line

International Nuclear Information System (INIS)

Wong, Vincent; Boyd, Robert W.; Stroud, C. R. Jr.; Bennink, Ryan S.; Marino, Alberto M.

2003-01-01

We present the results of a pump-probe laser spectroscopic investigation of the Doppler-broadened sodium D1 resonance line. We find 13 resonances in the resulting spectra. These observations are well described by the numerical predictions of a four-level atomic model of the hyperfine structure of the sodium D1 line. We also find that many, but not all, of these features can be understood in terms of processes originating in a two-level or three-level subset of the full four-level model. The processes we observed include forward near-degenerate four-wave mixing and saturation in a two-level system, difference-frequency crossing and nondegenerate four-wave mixing in a three-level V system, electromagnetically induced transparency and optical pumping in a three-level lambda system, cross-transition resonance in a four-level double-lambda system, and conventional optical pumping. Most of these processes lead to sub-Doppler or even subnatural linewidths. The dependence of these resonances on the pump intensity and pump detuning from atomic resonance are also studied

Intermediate-Size Inducer Pump design report. [LMFBR

Energy Technology Data Exchange (ETDEWEB)

Boardman, T.J.

1979-06-15

This report summarizes the mechanical, structural, and hydrodynamic design of the Intermediate-Size Inducer Pump (ISIP). The design was performed under Atomics International's DOE Base Technology Program by the Atomics International and Rocketdyne Divisions of Rockwell International. The pump was designed to utilize the FFTF prototype pump frame as a test vehicle to test the inducer, impeller, and diffuser plus necessary adapter hardware under simulated Large Scale Liquid Metal Fast Breeder Reactor service conditions. The report describes the design requirements including the purpose and objectives, and discusses those design efforts and considerations made to meet the requirements. Included in the report are appendices showing calculative methods and results. Also included are overall assembly and layout drawings plus some details used as illustrations for discussion of the design results and the results of water tests performed on a model of the inducer.

Design and operation of a small (benchtop) pumped sodium loop

International Nuclear Information System (INIS)

Trevillion, E.A.; Rowe, D.M.J.

1975-08-01

The report outlines the design and operation of a small (benchtop) pumped sodium loop (sodium, 650g). The loop incorporates a diffusion cold trap to control the oxygen impurity level in the sodium and a sodium sampler/distillation unit to enable sodium samples to be analysed for impurities. Sodium flow rates of up to 5.5cm.s -1 (1cm 3 .s -1 ) have been achieved at temperatures up to 673.2K (400 0 C) and temperatures of up to 1023.2K (750 0 C) have been achieved under static conditions. A device for the addition and removal of metallic speciments to and from the loop sodium without contamination of either the specimens or the sodium is also described. (author)

The Design of the Annular Linear Induction EM Pump with a Sodium Flowrate of 35 kg/sec

International Nuclear Information System (INIS)

Kim, Hee Reyoung; Lee, Tae Ho; Lee, Yong Bum

2010-01-01

Generally, an electromagnetic (EM) pump has been employed to circulate liquid metal with a high electrical conductivity by the electromagnetic force (Lorentz force) which is the cross product of the magnetic field and its perpendicular current. Therefore, an EM pump has its advantages over a mechanical pump such as no noise, no rotating parts, and its simplicity. Actually, it can be used for the Sodium Fast Reactor (SFR) which uses liquid sodium with a high electrical conductivity as a coolant. In the present study, the annular linear induction EM pump with a flowrate of 2,265 L/min and a head of 4 bar is designed by using an electrical equivalent circuit method which is applied to linear induction machines. The designed pump will be used for the verification of the elements, which are IHX, AHX and DHX, in the component performance test sodium loop for the sodium thermo-hydraulic experimental facility. The pump is manufactured and fabricated to meet the requirements of the material and a functioning in high temperature-sodium environments. The P-Q characteristic is theoretically calculated on the designed pump according to the input currents and voltage

Inadvertent raising of levels in the FFTF primary sodium pumps. Final unusual occurrence report, HEDL 79-34 (FFTF-58)

International Nuclear Information System (INIS)

Kuechle, J.D.

1981-01-01

The final unusual occurrence report describes the inadvertent raising of the sodium level in the FFTF primary sodium pumps during system testing. This event is now judged to have caused permanent deformation of the primary pump shaft on loop 1 during a period when pump rotation was stopped and sodium level in the pump tank was inadvertently increased. The shaft was subsequently removed, straightened, and returned to service in the spare FFTF pump

Advanced intermediate temperature sodium-nickel chloride batteries with ultra-high energy density

Science.gov (United States)

Li, Guosheng; Lu, Xiaochuan; Kim, Jin Y.; Meinhardt, Kerry D.; Chang, Hee Jung; Canfield, Nathan L.; Sprenkle, Vincent L.

2016-02-01

Sodium-metal halide batteries have been considered as one of the more attractive technologies for stationary electrical energy storage, however, they are not used for broader applications despite their relatively well-known redox system. One of the roadblocks hindering market penetration is the high-operating temperature. Here we demonstrate that planar sodium-nickel chloride batteries can be operated at an intermediate temperature of 190 °C with ultra-high energy density. A specific energy density of 350 Wh kg-1, higher than that of conventional tubular sodium-nickel chloride batteries (280 °C), is obtained for planar sodium-nickel chloride batteries operated at 190 °C over a long-term cell test (1,000 cycles), and it attributed to the slower particle growth of the cathode materials at the lower operating temperature. Results reported here demonstrate that planar sodium-nickel chloride batteries operated at an intermediate temperature could greatly benefit this traditional energy storage technology by improving battery energy density, cycle life and reducing material costs.

Flavonolignans As a Novel Class of Sodium Pump Inhibitors

Czech Academy of Sciences Publication Activity Database

Kubala, M.; Čechová, P.; Geletičová, J.; Biler, M.; Štenclová, T.; Trouillas, P.; Biedermann, David

2016-01-01

Roč. 7, Mar 30 (2016), s. 115 ISSN 1664-042X R&D Projects: GA ČR(CZ) GA15-03037S Institutional support: RVO:61388971 Keywords : sodium pump * Na+/K+-ATPase * flavonolignans Subject RIV: CE - Biochemistry Impact factor: 4.134, year: 2016

Development, design, construction and testing of pumps, intermediate heat exchangers and manipulator systems for in-service inspection of SNR 300

International Nuclear Information System (INIS)

Vroom, J.P.; Heslenfeld, M.W.; Westerweele, W.J.; Willigen, A. van

1978-01-01

The first part of this paper reviews the development, design, construction and testing of sodium pumps and intermediate heat exchangers as carried out by NERATOOM in the Netherlands. Testing of full-size components under operational conditions yielded important information for the design of the components for SNR 300. Information is also given in brief on the manufacture of the components. The second part reviews the work done on manipulator systems for in-service inspection as carried out by INTERATOM in Germany. In this field again experience gained from tests had important consequences for the design of the apparatus for SNR 300. (author)

Specialists' meeting on cavitation criteria for designing mechanisms working in sodium: Application to pumps. Summary report

International Nuclear Information System (INIS)

2002-01-01

The purpose of the meeting was to provide a forum for discussions and exchanges of views on cavitation phenomena in sodium, cavitation tests on pump models in water and sodium, application of test results to LMFBR plants, impact on sodium pump design. Topics of interest were also detection methods for cavitation during tests and cavitation problems in electro-magnetic pumps. Two categories of papers were presented: national position papers and specialised topical papers. The main topics discussed, in three sessions were the following: National papers on cavitation; cavitation tests, performance, measuring methods and results; application of test results and implications on the future programmes

Characterization and isolation of a light driven sodium pump from membranes of Halobacterium halobium. Final technical progress report

International Nuclear Information System (INIS)

MacDonald, R.E.

1982-01-01

We investigated three aspects of the light driven sodium pump (halorhodopsin, which appear to be crucial to our understanding of the mechanisms employed by Halobacterium halobium and to further investigate this unique system of energy conservation. We characterized the molecular mechanisms of transmembrane sodium transport in vesicles from H. halobium with particular reference to the mechanism of couplins of light energy to net sodium translocation. We develop procedures and techniques for extracting the components of the light driven sodium pump from membranes and incorporating them into artificial membrane systems. We examine the mechanism of conversion of bacteriorhodopsin from an active to an inactive form in membrane vesicles and to relate this alternative state of this pigment to the presence of the light driven sodium pump

Pumps modelling of a sodium fast reactor design and analysis of hydrodynamic behavior

Directory of Open Access Journals (Sweden)

Ordóñez Ródenas José

2016-01-01

Full Text Available One of the goals of Generation IV reactors is to increase safety from those of previous generations. Different research platforms have been identified the need to improve the reliability of the simulation tools to ensure the capability of the plant to accommodate the design basis transients established in preliminary safety studies. The paper describes the modelling of primary pumps in advanced sodium cooled reactors using the TRACE code. Following the implementation of the models, the results obtained in the analysis of different design basis transients are compared with the simplifying approximations used in reference models. The paper shows the process to obtain a consistent pump model of the ESFR (European Sodium Fast Reactor design and the analysis of loss of flow transients triggered by pumps coast–down analyzing the thermal hydraulic neutronic coupled system response. A sensitivity analysis of the system pressure drops effect and the other relevant parameters that influence the natural convection after the pumps coast–down is also included.

Nonlinear seismic analysis of a large sodium pump

International Nuclear Information System (INIS)

Huang, S.N.

1985-01-01

The bearings and seismic bumpers used in a large sodium pump of a typical breeder reactor plant may need to be characterized by nonlinear springs and gaps. Then, nonlinear seismic analysis utilizing the time-history method is an effective way to predict the pump behaviors during seismic events, especially at those bearing and seismic bumper areas. In this study, synthesized time histories were developed based on specified seismic response spectra. A nonlinear seismic analysis was then conducted and results were compared with those obtained by linear seismic analysis using the response spectrum method. In contrast to some previous nonlinear analysis trends, the bearing impact forces predicted by nonlinear analysis were higher than those obtained by the response spectrum method. This might be due to the larger gaps and stiffer bearing supports used in this specific pump. However, at locations distant from the impact source, the nonlinear seismic analysis has predicted slightly less responses than those obtained by linear seismic analysis. The seismically induced bearing impact forces were used to study the friction induced thermal stresses on the hydrostatic bearing and to predict the coastdown time of the pump. Results and discussions are presented

Nonlinear seismic analysis of a large sodium pump

International Nuclear Information System (INIS)

Huang, S.N.

1985-01-01

The bearings and seismic bumpers used in a large sodium pump of a typical breeder reactor plant may need to be characterized by nonlinear springs and gaps. Then, nonlinear seismic analysis utilizing the time-history method is an effective way to predict the pump behaviors during seismic events - especially at those bearing and seismic bumper areas. In this study, synthesized time histories were developed based on specified seismic response spectra. A nonlinear seismic analysis was then conducted and results were compared with those obtained by linear seismic analysis using the response spectrum method. In contrast to some previous nonlinear analysis trends, the bearing impact forces predicted by nonlinear analysis were higher than those obtained by the response spectrum method. This might be due to the larger gaps and stiffer bearing supports used in this specific pump. However, at locations distant from the impact source, the nonlinear seismic analysis has predicted slightly less responses than those obtained by linear seismic analysis. The seismically induced bearing impact forces were used to study the friction induced thermal stresses on the hydrostatic bearing and to predict the coastdown time of the pump. Results and discussions are presented

Comparison of cavitation tests on the SNR 300 prototype sodium pump, carried out using water at room temperature and liquid sodium at 5800C

International Nuclear Information System (INIS)

Fakkel, R.H.; Hoornweg, C.J.; Kamerling, B.; Ten Wolde, Tj.; Heslenfeld, M.W.; Mendte, W.K.; Bunjies, J.H.

1976-01-01

This paper gives results of tests carried out on a centrifugal pump in both a water and a sodium test facility. The pump tested is a prototype of the primary circulation pumps intended for a LMFBR 300 MWe nuclear power station (the SNR reactor) under construction at Kalkar, West Germany. The pump characteristics under various NPSH-conditions were investigated, and a comparison is made in the paper between the results of cavitation tests using water and liquid sodium. An attempt is made to account for differences in pump characteristics in both types of tests by referring to the physical properties of the liquids used (water and sodium). An attempt is also made to correlate the results obtained with the full-scale prototype to those obtained previously with a half-scale model of the impeller. The various test circuits used should be made identical, in order to avoid that differences in geometry should obscure essential features resulting from using different liquids. Yet, it showed that in this respect, the tests did not obey to this key-rule, reasons why the test results did not fully reveal the essential physical properties of either fluid under cavitating conditions. (author)

Reversal of sodium pump inhibitor induced vascular smooth muscle contraction with digibind. Stoichiometry and its implications.

Science.gov (United States)

Krep, H H; Graves, S W; Price, D A; Lazarus, M; Ensign, A; Soszynski, P A; Hollenberg, N K

1996-01-01

The possibility that a circulating sodium pump inhibitor contributes to the pathogenesis of volume-dependent hypertension via an action on vascular smooth muscle (VSM) is supported by multiple lines of investigation, but remains controversial. We had two goals in this study. The first was to compare the pattern of contractile response of rabbit aorta induced by two candidates, ouabain and a labile sodium pump inhibitor that we have identified in the peritoneal dialysate of volume-expanded hypertensive patients with chronic renal failure. Our second goal was to examine the ability of Digibind, a Fab fragment of antisera directed against digoxin, to reverse VSM contraction induced by both agents. Ouabain induced a concentration-dependent contraction, which was delayed in onset, was gradual, and reached a stable plateau after many hours. The labile sodium pump inhibitor induced a qualitatively similar series of responses. Digibind rapidly reversed the contractile responses to both sodium pump inhibitors, with a rate of relaxation that matched that induced by physical removal of the pump inhibitor from the bath. For ouabain, the Digibind:ouabain stoichiometry was highly predictable. When Digibind was present in a molar concentration equivalent to that of ouabain, or less, it had no effect. When the Digibind concentration was twice that of ouabain, complete relaxation occurred. Although the concentration:VSM response relationship for ouabain was steep, the concentration:effect interaction with Digibind was even more steep. The molar concentration of Digibind required to reverse the effects of the labile endogenous inhibitor from peritoneal dialysate was consistently lower than that for ouabain, which is compatible with either greater potency of the labile factor in VSM or greater affinity for Digibind. These findings are compatible with a role for one or more endogenous sodium pump inhibitors as the determinant of vascular smooth muscle tone in the volume

Laser optical pumping of sodium and lithium atom beams

International Nuclear Information System (INIS)

Cusma, J.T.

1983-01-01

The method of optical pumping with a continuous wave dye laser has been used to produce beams of polarized 23 Na atoms and polarized 6 Li atoms. Optical pumping of a 23 Na atom beam using either a multimode dye laser or a single frequency dye laser with a double passed acousto-optic modulator results in electron spin polarizations of 0.70-0.90 and nuclear spin polarizations of 0.75-0.90. Optical pumping of a 6 Li atom beam using a single frequency dye laser either with an acousto-optic modulator or with Doppler shift pumping results in electron spin polarizations of 0.77-0.95 and nuclear spin polarizations greater than 0.90. The polarization of the atom beam is measured using either the laser induced fluorescence in an intermediate magnetic field or a 6-pole magnet to determine the occupation probabilities of the ground hyperfine sublevels following optical pumping. The results of the laser optical pumping experiments agree with the results of a rate equation analysis of the optical pumping process which predicts that nearly all atoms are transferred into a single sublevel for our values of laser intensity and interaction time. The use of laser optical pumping in a polarized ion source for nuclear scattering experiments is discussed. The laser optical pumping method provides a means of constructing an intense source of polarized Li and Na ions

Pumps modelling of a sodium fast reactor design and analysis of hydrodynamic behavior - 15294

International Nuclear Information System (INIS)

Ordonez, J.; Lazaro, A.; Martorell, S.

2015-01-01

One of the goals of Generation IV reactors is to increase safety from those of previous generations. Different research platforms have identified the need to improve the reliability of the simulation tools to ensure the capability of the plant to accommodate the design basis transients established in preliminary safety studies. The paper describes the modeling of recirculation pumps in advanced sodium cooled reactors using the TRACE code. Following the implementation of the models, the results obtained in the analysis of different design basis transients are compared with the simplifying approximations used in reference models. The paper shows the process to obtain a consistent pump model of the ESFR (European Sodium Fast Reactor) design and the analysis of loss of flow transients triggered by pumps coast-down analyzing the thermal hydraulic neutronic coupled system response. A sensitivity analysis of the system pressure drops effect and the other relevant parameters that influence the natural convection after the pumps coast-down is also included. (authors)

Mode of Action of the Natural Insecticide, Decaleside Involves Sodium Pump Inhibition.

Science.gov (United States)

Rajashekar, Yallappa; Shivanandappa, Thimmappa

2017-01-01

Decalesides are a new class of natural insecticides which are toxic to insects by contact via the tarsal gustatory chemosensilla. The symptoms of their toxicity to insects and the rapid knockdown effect suggest neurotoxic action, but the precise mode of action and the molecular targets for decaleside action are not known. We have presented experimental evidence for the involvement of sodium pump inhibition in the insecticidal action of decaleside in the cockroach and housefly. The knockdown effect of decaleside is concomitant with the in vivo inhibition of Na+, K+ -ATPase in the head and thorax. The lack of insecticidal action by experimental ablation of tarsi or blocking the tarsal sites with paraffin correlated with lack of inhibition of Na+- K+ ATPase in vivo. Maltotriose, a trisaccharide, partially rescued the toxic action of decaleside as well as inhibition of the enzyme, suggesting the possible involvement of gustatory sugar receptors. In vitro studies with crude insect enzyme preparation and purified porcine Na+, K+ -ATPase showed that decaleside competitively inhibited the enzyme involving the ATP binding site. Our study shows that the insecticidal action of decaleside via the tarsal gustatory sites is causally linked to the inhibition of sodium pump which represents a unique mode of action. The precise target(s) for decaleside in the tarsal chemosensilla and the pathway linked to inhibition of sodium pump and the insecticidal action remain to be understood.

On the concept of resting potential--pumping ratio of the Na⁺/K⁺ pump and concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell.

Science.gov (United States)

Xu, Ning

2013-01-01

In animal cells, the resting potential is established by the concentration gradients of sodium and potassium ions and the different permeabilities of the cell membrane to them. The large concentration gradients of sodium and potassium ions are maintained by the Na⁺/K⁺ pump. Under physiological conditions, the pump transports three sodium ions out of and two potassium ions into the cell per ATP hydrolyzed. However, unlike other primary or secondary active transporters, the Na⁺/K⁺ pump does not work at the equilibrium state, so the pumping ratio is not a thermodynamic property of the pump. In this article, I propose a dipole-charging model of the Na⁺/K⁺ pump to prove that the three Na⁺ to two K⁺ pumping ratio of the Na⁺/K⁺ pump is determined by the ratio of the ionic mobilities of potassium to sodium ions, which is to ensure the time constant τ and the τ-dependent processes, such as the normal working state of the Na⁺/K⁺ pump and the propagation of an action potential. Further, the concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell are 0.3027 and 0.9788, respectively, and the sum of the potassium and sodium equilibrium potentials is -30.3 mV. A comparative study on these constants is made for some marine, freshwater and terrestrial animals. These findings suggest that the pumping ratio of the Na⁺/K⁺ pump and the ion concentration ratios play a role in the evolution of animal cells.

The design and testing of sodium pumps in the UK to meet the CDFR cavitation criteria

International Nuclear Information System (INIS)

Preece, G.E.; Macleod, I.D.; Wilkinson, D.

2002-01-01

A primary objective in the design of the sodium pumps for the UK Commercial Demonstration Fast Reactor has been to avoid cavitation during normal operation. This requirement arises from the need to avoid blade erosion and also, in the case of the Primary Sodium Pumps (PSP), the generation of cavitation noise which might otherwise interfere with instrumentation installed to detect noise of boiling in the core. This paper outlines the approach adopted to achieve a pump design with good cavitation performance and the programme of model testing carried out in a water loop to establish the cavitation boundaries for incipient cavitation of selected designs using both visual and acoustic techniques

Development of active magnetic bearings and ferrofluid seals toward oil free sodium pumps

International Nuclear Information System (INIS)

Sreedhar, B.K.; Kumar, R. Nirmal; Sharma, Prashant; Ruhela, Shivprakash; Philip, John; Sundarraj, S.I.; Chakraborty, N.; Mohana, M.; Sharma, Vijay; Padmakumar, G.; Nashine, B.K.; Rajan, K.K.

2013-01-01

Sodium centrifugal pumps employ conventional oil cooled bearings and mechanical seals to support the rotor assembly outside sodium and to seal the cover gas from the atmosphere. Although engineered safety features are incorporated in the design and detailed operational procedures formulated to ensure that no oil contamination of sodium can occur, there have been incidents of oil ingress into sodium. A design variant that eliminates the need for oil in top bearings and seals is therefore a promising option. This paper discusses the work in progress to develop a magnetic bearing and ferrofluid seal combination that can achieve this purpose

Intermediate size inducer pump - structural analysis and transient deformation studies

International Nuclear Information System (INIS)

Cheng, T.K.; Nishizaka, J.N.

1979-05-01

This report summarizes the structural and thermal transient deformation analysis of the Intermediate Size Inducer Pump. The analyses were performed in accordance to the requirements of N266ST310001, the specification for the ISIP. Results of stress analysis indicate that the thermal transient stress and strain are within the stress strain limits of RDT standard F9-4 which was used as a guide

Electron scattering from sodium at intermediate energies

International Nuclear Information System (INIS)

Mitroy, J.; McCarthy, I.E.

1986-10-01

A comprehensive comparison is made between theoretical calculations and experimental data for intermediate energy (≥ 10 eV) electron scattering from sodium vapour. The theoretical predictions of coupled-channels calculations (including one, two or four channels) do not agree with experimental values of the differential cross sections for elastic scattering or the resonant 3s to 3p excitation. Increasingly-more-sophisticated calculations, incorporating electron correlations in the target states, and also including core-excited states in the close-coupling expansion, are done at a few selected energies in an attempt to isolate the cause of the discrepancies between theory and experiment. It is found that these more-sophisticated calculations give essentially the same results as the two- and four-channel calculations using Hartree-Fock wavefunctions. Comparison of the sodium high-energy elastic differential cross sections with those of neon suggests that the sodium differential cross section experiments may suffer from systematic errors. There is also disagreement, at the higher energies, between theoretical values for the scattering parameters and those that are derived from laser-excited superelastic scattering and electron photon coincidence experiments. When allowance is made for the finite acceptance angle of the electron spectrometers used in the experiments by convoluting the theory with a function representing the distribution of electrons entering the electron spectrometer it is found that the magnitudes of the differences between theory and experiment are reduced

Mode of Action of the Natural Insecticide, Decaleside Involves Sodium Pump Inhibition.

Directory of Open Access Journals (Sweden)

Yallappa Rajashekar

Full Text Available Decalesides are a new class of natural insecticides which are toxic to insects by contact via the tarsal gustatory chemosensilla. The symptoms of their toxicity to insects and the rapid knockdown effect suggest neurotoxic action, but the precise mode of action and the molecular targets for decaleside action are not known. We have presented experimental evidence for the involvement of sodium pump inhibition in the insecticidal action of decaleside in the cockroach and housefly. The knockdown effect of decaleside is concomitant with the in vivo inhibition of Na+, K+ -ATPase in the head and thorax. The lack of insecticidal action by experimental ablation of tarsi or blocking the tarsal sites with paraffin correlated with lack of inhibition of Na+- K+ ATPase in vivo. Maltotriose, a trisaccharide, partially rescued the toxic action of decaleside as well as inhibition of the enzyme, suggesting the possible involvement of gustatory sugar receptors. In vitro studies with crude insect enzyme preparation and purified porcine Na+, K+ -ATPase showed that decaleside competitively inhibited the enzyme involving the ATP binding site. Our study shows that the insecticidal action of decaleside via the tarsal gustatory sites is causally linked to the inhibition of sodium pump which represents a unique mode of action. The precise target(s for decaleside in the tarsal chemosensilla and the pathway linked to inhibition of sodium pump and the insecticidal action remain to be understood.

Several particular aspects of hydrostatic shaft guide bearings in mechanical liquid sodium pumps

International Nuclear Information System (INIS)

Elie, X.

A number of problems arise with immersed hydrostatic shaft guide bearings in sodium pumps, mainly at high-temperature operation. Experience has shown that a substantial bearing clearance is required which, in present designs, takes a considerable amount of fluid from the pumps. A new design is suggested, resulting in a very appreciable reduction in the additional flow requirement, while maintaining a comparable load capacity by a hydrodynamic effect

Rotor dynamic studies of a vertical sodium pump supported on a spherical seat

International Nuclear Information System (INIS)

Asokkumar, S.; Ramalingam, P.; Baskar, S.; Balachander, K.; Kale, R.D.

1994-01-01

One of the important areas in the mechanical design of Primary Sodium Pumps (PSP) concerns with the problem of accommodating the differential thermal expansion between the pump support and the discharge pipe which function at substantially different temperatures. A spherical ball resting on a spherical split seat is designed to allow the tilting of the pump without creating significant stresses in the pump casing and the discharge pipe. To ascertain the dynamic performance of the pump and to validate the design, an experimental study was carried out with a 1/4 model spherical seat installed in an existing 50 cu.m/hr pump. The paper discusses the modeling criteria, details of theoretical/experimental studies and results obtained during testing. This paper also discusses details of full size test rig which is under construction. (author). 4 refs., 3 figs., 2 tabs

Effects of dietary magnesium on sodium-potassium pump action in the heart of rats

International Nuclear Information System (INIS)

Fischer, P.W.; Giroux, A.

1987-01-01

Sprague-Dawley rats were fed a basal AIN-76 diet containing 80, 200, 350, 500 or 650 mg of magnesium per kilogram of diet for 6 wk. Ventricular slices, as well as microsomal fractions, were prepared from the hearts and were used to determine sodium-potassium pump activity. Sodium-potassium pump activity was assessed in the microsomal membranes by determining the ouabain-inhibitable Na+, K+-ATPase activity and [ 3 H]ouabain binding, and in the ventricular slices, by determining ouabain-sensitive 86 Rb uptake under K+-free conditions. The ATPase activity increased with increasing dietary magnesium, so that in the hearts of those animals that were fed 500 and 650 mg of magnesium/kg diet, it was significantly greater than the activity in the hearts of the animals fed 80 and 200 mg/kg diet. Similarly, 86 Rb uptake by heart slices from rats fed 500 and 650 mg of magnesium/kg diet was significantly greater than the uptake by heart slices from animals fed 80 and 200 mg/kg diet. [ 3 H]Ouabain binding did not change with increasing dietary magnesium. Thus, magnesium deficiency appears to have no effect on the number of sodium-potassium pump sites, but does decrease the activity of the pump. It is suggested that this leads to an increase in intracellular Na+, resulting in a change in the membrane potential, and may contribute to the arrhythmias associated with magnesium deficiency

Experience on sodium removal from various components

Energy Technology Data Exchange (ETDEWEB)

Kamei, M; Kanbe, M; Yagisawa, H; Sasaki, S; Kataoka, H; Fukada, T; Ishii, Y; Saito, R; Mimoto, Y [O-arai Engineering Centre, PNC, Ibaraki-ken, Tokio (Japan)

1978-08-01

Since 1970, OEC (O-arai Engineering Center) has been Investigating the following methods for removal of sodium from the components of sodium plants: steam cleaning for the 50 MW Steam Generator, secondary proto-type pump of 'JOYO' and Dummy fuel assembly of 'JOYO', alcohol cleaning for Sector Model of Intermediate Heat Exchanger (IHX) of 'JOYO', a sector model of Sodium-to-Air cooler of 'JOYO' and a proto-type isolation valve of 'JOYO' and cleaning by vacuumization at high temperature for Regenerative Heat Exchanger. This report describes the outline of the Sodium Disposal Facility and experience of sodium removal processing on the 50 MW Steam Generator, the crevices of the experimental sub-assemblies, the Fuel Handling Machine of 'MONJU' and the Regenerative Heat Exchanger of the Sodium Flow Test Facility. Through these experiences it was noted that, (1) Removal of sodium from crevices such as in bolted joints are very difficult. (2) Consideration is needed in the removal process where material damage might occur from the generation of hydro-oxides. (3) Some detection device to tell the completion of sodium removal as well as the end of reaction is required. (4) Requalification rules should be clarified. Efforts in this direction have been made in the case of a 'JOYO' prototype pump by reinstalling it after sodium removal five times. (author)

Experience on sodium removal from various components

International Nuclear Information System (INIS)

Kamei, M.; Kanbe, M.; Yagisawa, H.; Sasaki, S.; Kataoka, H.; Fukada, T.; Ishii, Y.; Saito, R.; Mimoto, Y.

1978-01-01

Since 1970, OEC (O-arai Engineering Center) has been Investigating the following methods for removal of sodium from the components of sodium plants: steam cleaning for the 50 MW Steam Generator, secondary proto-type pump of 'JOYO' and Dummy fuel assembly of 'JOYO', alcohol cleaning for Sector Model of Intermediate Heat Exchanger (IHX) of 'JOYO', a sector model of Sodium-to-Air cooler of 'JOYO' and a proto-type isolation valve of 'JOYO' and cleaning by vacuumization at high temperature for Regenerative Heat Exchanger. This report describes the outline of the Sodium Disposal Facility and experience of sodium removal processing on the 50 MW Steam Generator, the crevices of the experimental sub-assemblies, the Fuel Handling Machine of 'MONJU' and the Regenerative Heat Exchanger of the Sodium Flow Test Facility. Through these experiences it was noted that, (1) Removal of sodium from crevices such as in bolted joints are very difficult. (2) Consideration is needed in the removal process where material damage might occur from the generation of hydro-oxides. (3) Some detection device to tell the completion of sodium removal as well as the end of reaction is required. (4) Requalification rules should be clarified. Efforts in this direction have been made in the case of a 'JOYO' prototype pump by reinstalling it after sodium removal five times. (author)

Experience on sodium removal from various components

International Nuclear Information System (INIS)

Kamei, M.; Kanbe, M.; Yagisawa, H.; Sasaki, S.; Kataoka, H.

1978-02-01

Since 1970, OEC (O-arai Engineering Center) has been investigating the following methods for removal of sodium from the components of sodium plants: steam cleaning for the 50 MW Steam Generator, secondary proto-type pump of ''JOYO'' and Dummy fuel assembly of ''JOYO'', alcohol cleaning for Sector Model of Intermediate Heat Exchanger (IHX) of ''JOYO'', a sector model of Sodium-to-Air cooler of ''JOYO'' and a proto-type Isolation valve of ''JOYO'' and cleaning by vacuumization at high temperature for Regenerative Heat Exchanger. This report describes the outline of the Sodium Disposal Facility and experience of sodium removal processing on the 50 MW Steam Generator, the crevices of the experimental subassemblies, the Fuel Handling Machine of ''MONJU'' and the Regenerative Heat Exchanger of the Sodium Flow Test Facility. Through these experiences it was noted that, (1) Removal of Sodium from crevices such as in bolted joints are very difficult. (2) Consideration is needed in the removal process where material damage might occur from the generation of hydro-oxides. (3) Some detection device to tell the completion of sodium removal as well as the end of reaction is required. (4) Requalification rules should be clarified. Efforts in this direction have been made in the case of a ''JOYO'' prototype pump by reinstalling it after sodium removal five times. (author)

MODELING OF THE HEAT PUMP STATION ADJUSTABLE LOOP OF AN INTERMEDIATE HEAT-TRANSFER AGENT (Part I

Directory of Open Access Journals (Sweden)

Sit B.

2009-08-01

Full Text Available There are examined equations of dynamics and statics of an adjustable intermediate loop of heat pump carbon dioxide station in this paper. Heat pump station is a part of the combined heat supply system. Control of transferred thermal capacity from the source of low potential heat source is realized by means of changing the speed of circulation of a liquid in the loop and changing the area of a heat-transmitting surface, both in the evaporator, and in the intermediate heat exchanger depending on the operating parameter, for example, external air temperature and wind speed.

Internal fluid flow management analysis for Clinch River Breeder Reactor Plant sodium pumps

International Nuclear Information System (INIS)

Cho, S.M.; Zury, H.L.; Cook, M.E.; Fair, C.E.

1978-12-01

The Clinch River Breeder Reactor Plant (CRBRP) sodium pumps are currently being designed and the prototype unit is being fabricated. In the design of these large-scale pumps for elevated temperature Liquid Metal Fast Breeder Reactor (LMFBR) service, one major design consideration is the response of the critical parts to severe thermal transients. A detailed internal fluid flow distribution analysis has been performed using a computer code HAFMAT, which solves a network of fluid flow paths. The results of the analytical approach are then compared to the test data obtained on a half-scale pump model which was tested in water. The details are presented of pump internal hydraulic analysis, and test and evaluation of the half-scale model test results

Transient Resonance Raman Spectroscopy of a Light-Driven Sodium-Ion-Pump Rhodopsin from Indibacter alkaliphilus.

Science.gov (United States)

Kajimoto, Kousuke; Kikukawa, Takashi; Nakashima, Hiroki; Yamaryo, Haruki; Saito, Yuta; Fujisawa, Tomotsumi; Demura, Makoto; Unno, Masashi

2017-05-04

Sodium-ion-pump rhodopsin (NaR) is a microbial rhodopsin that transports Na + during its photocycle. Here we explore the photocycle mechanism of NaR from Indibacter alkaliphilus with transient absorption and transient resonance Raman spectroscopy. The transient absorption data indicate that the photocycle of NaR is K (545 nm) → L (490 nm)/M (420 nm) → O 1 (590 nm) → O 2 (560 nm) → NaR, where the L and M are formed as equilibrium states. The presence of K, L, M, and O intermediates was confirmed by the resonance Raman spectra with 442 and 532 nm excitation. The main component of the transient resonance Raman spectra was due to L which contains a 13-cis retinal protonated Schiff base. The presence of an enhanced hydrogen out-of-plane band as well as its sensitivity to the H/D exchange indicate that the retinal chromophore is distorted near the Schiff base region in L. Moreover, the retinal Schiff base of the L state forms a hydrogen bond that is stronger than that of the dark state. These observations are consistent with a Na + pumping mechanism that involves a proton transfer from the retinal Schiff base to a key aspartate residue (Asp116 in Krokinobacter eikastus rhodopsin 2) in the L/M states.

Electromagnetic pump technology

International Nuclear Information System (INIS)

Prabhakar, R.

1994-01-01

Fast Breeder Reactors have an important role to play in our nuclear power programme. Liquid metal sodium is used as the coolant for removing fission heat generated in fast reactors and a distinctive physical property of sodium is its high electrical conductivity. This enables application of electromagnetic (EM) pumps, working on same principle as electric motors, for pumping liquid sodium. Due to its lower efficiency as compared to centrifugal pumps, use of EM pumps has been restricted to reactor auxiliary circuits and experimental facilities. As part of our efforts to manufacture fast reactor components indigenously, work on the development of two types of EM pumps namely flat linear induction pump (FLIP) and annular linear induction pump (ALIP) has been undertaken. Design procedures based on an equivalent circuit approach have been established and results from testing a 5.6 x 10E-3 Cum/s (20 Cum/h) FLIP in a sodium loop were used to validate the procedure. (author). 7 refs., 6 figs

Stability of penicillin G sodium diluted with 0.9% sodium chloride injection or 5% dextrose injection and stored in polyvinyl chloride bag containers and elastomeric pump containers.

Science.gov (United States)

Hossain, Mirza Akram; Friciu, Mihaela; Aubin, Sebastien; Leclair, Grégoire

2014-04-15

The stability of penicillin G sodium solutions stored in polyvinyl chloride (PVC) bags or elastomeric pump containers was studied. Test samples were prepared by diluting powdered penicillin G sodium (10 million units/10-mL vial) to solutions of 2,500 or 50,000 units/mL with 0.9% sodium chloride injection or 5% dextrose injection. The preparations were transferred to 250-mL PVC bags and elastomeric pump containers. All samples were prepared in triplicate and stored at 5°C. Chemical stability was measured by a stability-indicating high-performance liquid chromatographic (HPLC) assay and by pH evaluation. Particulate matter was evaluated according to compendial standards using a light-obscuration particle count test. Preparations were visually examined throughout the study. After 21 days of storage, all test samples remained chemically stable, with an HPLC assay recovery value of more than 90% of the initial value. After 28 days, all samples prepared with either diluent and stored in PVC bags, as well as the samples diluted to 2,500 units/mL with sodium chloride injection and stored in elastomeric pump containers, did not meet the recovery acceptance limit. For all test samples, the mean pH consistently decreased during storage, from about 6.4 to about 5.5. Particle counts remained acceptable throughout the study, and no change in appearance was observed. Penicillin G for injection (2,500 and 50,000 units/mL) diluted in 0.9% sodium chloride injection or 5% dextrose injection and stored at 5°C in PVC containers or elastomeric pump containers was physically and chemically stable for a period of at least 21 days.

The development of a cavitation free sodium pump for the breeder reactor

International Nuclear Information System (INIS)

Baladi, J.Y.; Nyilas, C.P.

1986-01-01

The sodium pumps for a liquid metal fast breeder reactor must be designed for exceptionally high reliability and long life. The principal adverse factor which tends to limit the primary pump life is cavitation which becomes potentially severe under off-design flow conditions caused by the requirement of two loop operations which resulted in a large operating flow range. This problem prompted an extensive study which included experimental investigations of scaled down and full size pumps. The investigations involved visual observations, acoustic signature recordings, and physical characteristic measurements of the model and full size impellers. The blade configuration of the model was modified several times. This paper describes the test facilities erected for this study, discusses the experimental techniques employed, and presents a sample of the experimental results

Removal of sodium from the component of the sodium purification loop

International Nuclear Information System (INIS)

Kim, Byung Ho; Jeong, Kyung Chai; Jeong, Ji Young; Kim, Jong Man; Choi, Byung Hae; Nam, Ho Yun

2005-01-01

The purpose of a cleaning process is to remove the residual sodium adhering to the component walls once it has been properly drained. It is necessary to clean and decontaminate a component, especially the large components of the primary coolant system; such as the intermediate heat exchangers and the primary pump. Improper and inadequate cleaning has in a number of cases resulted in problems in the storage, handling, and reuse of components. Several types of failures due to improper cleaning procedures have been defined in the past. Inadequate and incomplete removal of sodium results in residues which may contain metallic sodium and alkaline compounds such as sodium hydroxide, sodium oxide, sodium carbonate, and various types of alcoholates. Reinsertion of components containing these compounds into a high-temperature sodium system can result in either the intergranular penetration characteristic of a high-oxygen sodium or an accelerated corrosion due to oxygen. The methods used for cleaning sodium equipment depend on the condition and types of equipment to be cleaned and whether the equipment is to be reused. Cleaning methods are needed that will avoid a deleterious local overheating, material surface degradation or deposits, chemical, physical, or mechanical damage, and external effects. This paper discusses a steam-nitrogen gas cleaning method for the routine applications that permits the reuse of the cold trap in sodium

A resting bottom sodium cooled fast reactor

International Nuclear Information System (INIS)

Costes, D.

2012-01-01

This follows ICAPP 2011 paper 11059 'Fast Reactor with a Cold Bottom Vessel', on sodium cooled reactor vessels in thermal gradient, resting on soil. Sodium is frozen on vessel bottom plate, temperature increasing to the top. The vault cover rests on the safety vessel, the core diagrid welded to a toric collector forms a slab, supported by skirts resting on the bottom plate. Intermediate exchangers and pumps, fixed on the cover, plunge on the collector. At the vessel top, a skirt hanging from the cover plunges into sodium, leaving a thin circular slit partially filled by sodium covered by argon, providing leak-tightness and allowing vessel dilatation, as well as a radial relative holding due to sodium inertia. No 'air conditioning' at 400 deg. C is needed as for hanging vessels, and this allows a large economy. The sodium volume below the slab contains isolating refractory elements, stopping a hypothetical corium flow. The small gas volume around the vessel limits any LOCA. The liner cooling system of the concrete safety vessel may contribute to reactor cooling. The cold resting bottom vessel, proposed by the author for many years, could avoid the complete visual inspection required for hanging vessels. However, a double vessel, containing support skirts, would allow introduction of inspecting devices. Stress limiting thermal gradient is obtained by filling secondary sodium in the intermediate space. (authors)

The Grand Quevilly thermal test station - the SMW sodium circuit with a generator of superheated steam at 545 deg

International Nuclear Information System (INIS)

Robin, M.G.

1964-01-01

A 5 MW installation is described which is a reduced model of the heat exchange system of a sodium-cooled reactor. This plant, which is situated at Grand Quevilly (near Rouen), consists of: 1 - A primary sodium loop made up of a sodium re-heater running on heavy diesel oil, a mechanical pump and an intermediate exchanger made up of clusters of tubes fitted with baffles. 2 - A NaK(56 per cent of K) secondary loop consisting mainly of a mechanical pump and a double-wall steam generator with forced circulation and complete vaporization. 3 - A tertiary water loop consisting of the inside of the steam generator pipes, a pressure-reducing valve which cools down the super-heated fluid and acts as a turbine, a condenser, a charge-pump and a supply pump for the boiler. The heat is given finally to a water-source flowing into the Seine. Two important points of the installation are: - The water treatment unit - The control and regulation system Apart from the general satisfactory operation of the installation which it is hoped to obtain, a careful study will be made of the heat transmission coefficients of the important equipment such as the intermediate exchanger and the steam generator. The construction was finished on April 28, 1964. (author) [fr

Sodium-immersed self-cooled electromagnetic pump design and development of a large-scale coil for high temperature

International Nuclear Information System (INIS)

Oto, Akihiro; Naohara, Nobuyuki; Ishida, Masayoshi; Katsuki, Kenji; Kumazawa, Ryouji

1995-01-01

A sodium-immersed, self-cooled electromagnetic (EM) pump was recently studied as a prospective innovative technology to simplify a fast breeder reactor plant system. The EM pump for a primary pump, a pump type, was designed, and the structural concept and the system performance were clarified. For the flow control method, a constant voltage/frequency method was preferable from the point of view of pump performance and efficiency. The insulation life was tested on a large-scale coil at high temperature as part of the development of a large-capacity EM pump. Mechanical and electrical damage were not observed, and the insulation performance was quite good. The insulation system could also be applied to large-scale coils

Crystal structure of the plasma membrane proton pump

DEFF Research Database (Denmark)

Pedersen, Bjørn P.; Buch-Pedersen, Morten Jeppe; Morth, J. Preben

2007-01-01

A prerequisite for life is the ability to maintain electrochemical imbalances across biomembranes. In all eukaryotes the plasma membrane potential and secondary transport systems are energized by the activity of P-type ATPase membrane proteins: H1-ATPase (the proton pump) in plants and fungi1......-3, and Na1,K1-ATPase (the sodium-potassium pump) in animals4. The name P-type derives from the fact that these proteins exploit a phosphorylated reaction cycle intermediate of ATP hydrolysis5.The plasma membrane proton pumps belong to the type III P-type ATPase subfamily, whereas Na1,K1-ATPase and Ca21......- ATPase are type II6. Electron microscopy has revealed the overall shape of proton pumps7, however, an atomic structure has been lacking. Here we present the first structure of a P-type proton pump determined by X-ray crystallography. Ten transmembrane helices and three cytoplasmic domains define...

Cavitation erosion scaling: tests on a pump impeller in water and in sodium

International Nuclear Information System (INIS)

Dorey, J.M.; Rascalou, T.

1992-01-01

Tests to quantify cavitation agressivity carried out in water and in sodium (400 deg) on a model pump impeller are presented. The polished samples method has been used. It can be now applied to curved surfaces such as impeller blades with the help of new measurement devices. Results are discussed regarding scaling laws for fluid-to-fluid transposition

Study of an electromagnetic pump applied to a primary main pump of a large scale sodium cooled reactor

International Nuclear Information System (INIS)

Aizawa, Kosuke; Kotake, Shoji; Chikazawa, Yoshitaka; Ara, Kuniaki; Araseki, Hideo; Aizawa, Rie; Ota, Hiroyuki

2009-01-01

This paper describes a future innovative design options with a parallel electromagnetic pump (EMP) system as the main circulating pump of the JSFR design. A conceptual design of EMPs integrated with an intermediate heat exchanger (IHX) is carried out. The major design parameters are consistent with the current JSFR design, where the main flow rate is 630 m 3 /min and the flow halving time is the same of the mechanical pump with the similar reliability. As a result of several design studies, a five parallel EMPs with IHX system has been selected from the geometry suitability for JSFR design. The EMP advantages comparing with mechanical pumps are investigated from the views of in-service inspection, maintenance and reliability. Numerical analysis with two dimensional MHD codes is conducted on a former experiment of a 160 m 3 /min flow rate EMP. The overall trend of the experimental data and the numerical results agrees with that in small-scale EMPs. However, the difference between the experimental data and the numerical results seems larger compared with the small-scale EMPs, which comes from large magnetic Reynolds number and interaction parameter of 160 m 3 /min EMP. (author)

Intermediate-scale tests of sodium interactions with calcite and dolomite aggregate concretes

International Nuclear Information System (INIS)

Randich, E.; Acton, R.U.

1983-09-01

Two intermediate-scale tests were performed to compare the behavior of calcite and dolomite aggregate concretes when attacked by molten sodium. The tests were performed as part of an interlaboratory comparison between Sandia National Laboratories and Hanford Engineering Development Laboratories. Results of the tests at Sandia National Laboratories are reported here. The results show that both concretes exhibit similar exothermic reactions with molten sodium. The large difference in reaction vigor suggested by thermodynamic considerations of CO 2 release from calcite and dolomite was not realized. Penetration rates of 1.4 to 1.7 mm/min were observed for short periods of time with reaction zone temperatures in excess of 800 0 C during the energetic attack. The penetration was not uniform over the entire sodium-concrete contact area. Rapid attack may be localized due to inhomogeneities in the concrete. The chemical reaction zone is less then one cm thick for the calcite concrete but is about seven cm thick for the dolomite concrete

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)

Predictive Reliability Assessment of the Automatic Clutch on a Primary Sodium Pump Drive

International Nuclear Information System (INIS)

Westwell, P.

1975-01-01

This paper examines the reliability of a group of three clutch couplings each mounted between a pony motor and the main drive for the primary sodium pumps. The sodium pumps specification requires that continuously running AC pony motors be fitted to give a guaranteed 10% drive to the pumps in the event of a main supply failure. The drive to the main shaft is via 3 : 1 reduction gearing such that a six pole pony motor running at 300 rpm would drive the main shaft at 100 rpm i.e., 10% of its rated speed. In order that the pony motor drive could be permanently energised during normal operation a free wheeling clutch is fitted between the motor and the reduction gearing. The type of clutch chosen is. the Synchro-Self Shifting (SSS) clutch, shown in Figure 1. This type of clutch has proved itself under fairly onerous operating conditions, but is normally mounted on a horizontal driving shaft whereas in this case because of space limitations, it is necessary to mount it vertically. The reliability target set is that the chance of losing all three independent back-up pony motor drives on loss of main supplies should fall within the 10 -5 - 10 -6 band. Since the electrical supplies and other parts of the pony motor drives have been assessed within this target and some doubts expressed about the clutch it was now necessary to look at this in some detail

The development of a cavitation free sodium pump for the breeder reactor

International Nuclear Information System (INIS)

Baladi, J.Y.; Nyilas, C.P.

1986-12-01

The sodium pumps for a liquid metal fast breeder reactor must be designed for exceptionally high reliability and long life. The principal adverse factor which tends to limit the primary pump life is cavitation which becomes potentially severe under off-design flow conditions caused by the requirement of two loop operations which resulted in a large operating flow range. This problem prompted an extensive study which included experimental investigations of scaled down and full size pumps. The investigations involved visual observations, acoustic signature recordings, and physical characteristic measurements of the model and full size impellers. The blade configuration of the model was modified several times. After each modification intensive testing was conducted with feedback to established design criteria. The results obtained from the final configuration showed excellent cavitation performance. This configuration was then machined on the full scale impeller and tested. The results confirmed acceptable performance in the entire range of operating conditions. This paper describes the test facilities erected for this study, discusses the experimental techniques employed, and presents the experimental techniques employed, and presents a sample of the experimental results

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

Determination of the full characteristics of a journal bearing for a fast reactor sodium pump using a full scale model bearing operating in water

International Nuclear Information System (INIS)

Gilroy, J.E.; Dostal, M.; Jones, R.P.

1988-01-01

This paper describes the analytical and experimental work carried out in support of a sodium-lubricated hydrostatic bearing for the CDFR primary sodium pump. The principle objective of the work was to establish bearing characteristics under steady-state and transient running conditions. A knowledge of these characteristics is necessary for the determination of the dynamic performance of the pump under normal and transient operating conditions and also under earthquake loading conditions

Failure rate evaluation for different components operating in sodium, based on operating experience of the RAPSODIE and the PHENIX reactors and the test loops

International Nuclear Information System (INIS)

Boisseau, J.; Dorey, J.; Hedin, F.; Le Floch, C.

1982-01-01

The failure rates of the following components, valves operating in sodium, mechanical and electromagnetic pumps, and heat exchangers including intermediate heat exchangers, cold traps, steam generators, are evaluated by analysing the main incidents which occurred on these components. Therefore, this paper contains an evaluation of the operating experience of components working in sodium and of the reliability of these components

Cleaning of Sodium in the Cold Trap

International Nuclear Information System (INIS)

Kim, Byung Ho; Jeong, Ji Young; Kim, Jong Man; Choi, Byung Hae; Nam, Ho Yun

2005-01-01

The purpose of a cleaning process is to remove the residual sodium adhering to the component walls once it has been properly drained. It is necessary to clean and decontaminate a component, especially the large components of the primary coolant system; such as the intermediate heat exchangers and the primary pump. Improper and inadequate cleaning has in a number of cases resulted in problems in the storage, handling, and reuse of components. Several types of failures due to improper cleaning procedures have been defined in the past. Inadequate and incomplete removal of sodium results in residues which may contain metallic sodium and alkaline compounds such as sodium hydroxide, sodium oxide, sodium carbonate, and various types of alcoholates. Reinsertion of components containing these compounds into a high-temperature sodium system can result in either the intergranular penetration characteristic of a high- oxygen sodium or an accelerated corrosion due to oxygen. The methods used for cleaning sodium equipment depend on the condition and types of equipment to be cleaned and whether the equipment is to be reused. Cleaning methods are needed that will avoid a deleterious local overheating, material surface degradation or deposits, chemical, physical, or mechanical damage, and external effects. This paper discusses a steam-nitrogen gas cleaning method for the routine applications that permits the reuse of the cold trap in sodium

MODELING OF THE HEAT PUMP STATION CONTROLABLE LOOP OF AN INTERMEDIATE HEAT-TRANSFER AGENT (Part II

Directory of Open Access Journals (Sweden)

Sit M.L.

2011-08-01

Full Text Available It is studied the model of the heat pump station controllable loop of an intermediate heat-transfer agent for the use in wineries. There are demonstrated transients after the disturbing action of the temperature on the input of cooling jacket of the fermentation stirred tank. There are compared different control laws of the object.

Sodium bicarbonate does not prevent postoperative acute kidney injury after off-pump coronary revascularization: a double-blinded randomized controlled trial.

Science.gov (United States)

Soh, S; Song, J W; Shim, J K; Kim, J H; Kwak, Y L

2016-10-01

Acute kidney injury (AKI) is a common morbidity after off-pump coronary revascularization. We investigated whether perioperative administration of sodium bicarbonate, which might reduce renal injury by alleviating oxidative stress in renal tubules, prevents postoperative AKI in off-pump coronary revascularization patients having renal risk factors. Patients (n=162) having at least one of the following AKI risk factors were enrolled: (i) age >70 yr; (ii) diabetes mellitus; (iii) chronic renal disease; (iv) congestive heart failure or left ventricular ejection fraction 24 h) relative to the control group (20 vs 6, P=0.003). Perioperative sodium bicarbonate administration did not decrease the incidence of AKI after off-pump coronary revascularization in high-risk patients and might even be associated with a need for prolonged ventilatory care. NCT01840241. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The replacement of an electromagnetic primary sodium sampling pump in the Fast Flux Test Facility

International Nuclear Information System (INIS)

Grygiel, M.L.; McCargar, C.G.

1985-01-01

On November 16, 1984 a leak was discovered in one of the Fast Flux Test Facility (FFTF) Primary Sodium Sampling System electromagnetic pumps. The leak was discovered in the course of routine cell entry to investigate a shorted trace heat element. The purpose of this paper is to describe the circumstances surrounding the occurrence of the leak, the actions taken to replace the damaged pump and the additional steps which were necessary to return the plant to power. In addition, the processes involved in producing the leak are described briefly. The relative ease of recovery from this incident is indicative of the overall feasibility of the Liquid Metal Reactor (LMR) operational concept

Sodium test of the Super-Phenix full size primary pump shaft on the CPV-1 test rig at ENEA-Brasimone

International Nuclear Information System (INIS)

Contardi, T.; Rapezzi, L.; Partiti, C.; Zola, M.; Denimal, P.

1984-01-01

Tests on FBR Superphenix primary pump shaft were performed within the sodium-cooled FBR common research and development programs provided for by the cooperation agreement between ENEA and CEA. These tests were performed in CPV-1 plant ENEA - Brasimone Energy Research Center. The CPV-1 rig was built by FIAT-TTG and reproduces the reactor operating conditions (sodium-temperature and level, shaft inclination, etc..). Furthermore, CPV-1 rig's most interesting feature is its possibility to apply seismic stresses to test section by means of an oleodynamic actuator. Pivoterie-1 test section was made by JEUMONT-SCHNEIDER which built Superphenix pumps too; it was given to ENEA by FIAT-TTG. Seismic tests were performed with the cooperation of ISMES and FIAT-TTG. (author)

Survey of pumps for tritium gas

International Nuclear Information System (INIS)

Dowell, T.M.

1983-05-01

This report considers many different types of pumps for their possible use in pumping tritium gas in the low, intermediate and high vacuum ranges. No one type of pump is suitable for use over the wide range of pumping pressure required in a typical pumping system. The favoured components for such a system are: bellows pump (low vacuum); orbiting scroll pump (intermediate vacuum); magnetically suspended turbomolecular pump (high vacuum); cryopump (high vacuum). Other pumps which should be considered for possible future development are: mound modified vane pump; SRTI wobble pump; roots pump with canned motor. It is proposed that a study be made of a future tritium pumping system in a Canadian tritium facility, e.g. a tritium laboratory

Potassium homeostasis during exercise in domestic species: the role of the sodium-potassium pump in skeletal muscle

NARCIS (Netherlands)

Everts, Maria E.

2001-01-01

In 1997, Jens Christian Skou was awarded the Nobel prize in Chemistry for his discovery and elegant description, some 40 years earlier, of the sodium-potassium (Na+,K+) pump in crab nerve fibres [37]. It is now widely accepted that this cation transport system is essential for cell function, and

The chemical, microbial, sensory and technological effects of intermediate salt levels as a sodium reduction strategy in fresh pork sausages.

Science.gov (United States)

Cluff, MacDonald; Steyn, Hannes; Charimba, George; Bothma, Carina; Hugo, Celia J; Hugo, Arno

2016-09-01

The reduction of sodium in processed meat products is synonymous with the use of salt replacers. Rarely has there been an assessment of the use of intermediate salt levels as a sodium reduction strategy in itself. In this study, 1 and 1.5% salt levels were compared with 0 and 2% controls in fresh pork sausages for effects on chemical, microbial, sensory and technological stability. Although significant (P sausages stored at 4 °C on days 6 and 9 and stored at -18 °C on days 90 and 180; taste, texture and overall liking during sensory evaluation; and % cooking loss, % total loss and % refrigeration loss. Consumers were able to differentiate between the 2 and 1% added NaCl treatments in terms of saltiness. This study indicated that salt reduction to intermediate levels can be considered a sodium reduction strategy in itself but that further research with regards to product safety is needed. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

CW light sources at the 589 nm sodium D2 line by sum-frequency mixing of diode pumped neodymium lasers

International Nuclear Information System (INIS)

Lü, Y F; Lu, J; Xu, L J; Sun, G C; Zhao, Z M; Gao, X; Lin, J Q

2010-01-01

We present a laser architecture to obtain continuous-wave (CW) light sources at the 589 nm sodium D2 line. A 808 nm diode-pumped a Nd:YLiF 4 (Nd:YLF) crystal emitting at 1053 nm. A part of the pump power was then absorbed by the Nd:YLF crystal. The remaining was used to pump a Nd:YAG crystal emitting at 1338 nm. Intracavity sum-frequency mixing at 1053 and 1338 nm was then realized in a LiB 3 O 5 (LBO) crystal to reach the yellow-orange radiation. We obtained a CW output power of 235 mW at 589 nm with a pump laser diode emitting 17.8 W at 808 nm

Spectroscopic analysis of sodium-bearing Z-pinch plasmas for their x-ray-laser pumping efficiency

International Nuclear Information System (INIS)

Apruzese, J.P.; Mehlman, G.; Davis, J.; Rogerson, J.E.; Scherrer, V.E.; Stephanakis, S.J.; Ottinger, P.F.; Young, F.C.

1987-01-01

Using axially resolved spectra, we have derived temperature and density profiles of sodium-bearing Z-pinch plasmas produced on the Naval Research Laboratory's Gamble-II generator. The variations in the output power of the Na X 1s 2 1 S 0 --1s2p 1 P 1 line which can be used to pump a Ne IX x-ray laser, are analyzed as functions of mass loading, temperature, and density. The fractional conversion of plasma energy to lasing lines is projected as 10/sup -3/ if an optimum neon lasant plasma can be prepared and pumped to saturation. This would require an increase in load current of less than or equal to 50% from the present 1.2 MA

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

Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

Energy Technology Data Exchange (ETDEWEB)

Barnes, M.J.

1998-12-07

The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variable on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB.

Seismic tests in sodium of the SPX-1 primary pump shaft carried out in the CPV-1 test rig at ENEA-Brasimone

International Nuclear Information System (INIS)

Contardi, T.; Rapezzi, L.; Le Coz, P.; Tigeot, Y.; Partiti, C.; Zola, M.; Denimal, P.

1988-01-01

Dynamic tests were carried out by ISMES, on behalf of ENEA and CEA and in co-operation with FIAT/TTG, on a SPX-1 primary pump shaft. These tests were conducted, mainly in sodium, in the CPV-1 test rig at the ENEA Brasimone Center. The excitation was applied to the flange supporting the hydrostatic bearing. After some preliminary analysis performed in absence of liquid sodium and at ambient temperature, the following tests were performed on the rig filled with sodium at operating temperature: (A) sine sweeps between 1 and 15 Hz, (B) ambient vibration investigation, and (C) seismic tests with a SSE acceleration time-history (20 s duration) calculated by CEA at hydrostatic bearing level. Two sets of seismic tests were carried out, each time increasing amplitudes up to 70% of SSE. This value was not exceeded for safety reasons and actuator power limit. The first set of tests began in nominal operating conditions; when 70% of SSE was reached, pressure feed to hydrostatic bearing was reduced lowering its effective support. This simulated a larger earthquake. The second set of tests was representative of SPX-1 pump actual operating conditions, because both hydrostatic bearing pressure and shaft rotating speed were simultaneously reduced following the primary pump characteristic curve. The tests allowed the SPX-1 pump rotating set to be widely qualified. Among the main results, it is worth noting that the stiffness of the hydrostatic bearing system was generally compatible with seismic requirements. Finally, it is worth pointing out that, in order to allow the above-mentioned tests to be carried out, a full seismic qualification of the CPV-1 test rig was necessary: thus, this rig might be used in the future for further seismic tests on LMFBR components and systems in sodium. (author). Figs and tabs

Sodium pumps in the Malpighian tubule of Rhodnius sp.

Directory of Open Access Journals (Sweden)

CARUSO-NEVES CELSO

2000-01-01

Full Text Available Malpighian tubule of Rhodnius sp. express two sodium pumps: the classical ouabain-sensitive (Na+ + K+ATPase and an ouabain-insensitive, furosemide-sensitive Na+-ATPase. In insects, 5-hydroxitryptamine is a diuretic hormone released during meals. It inhibits the (Na+ + K+ATPase and Na+ -ATPase activities indicating that these enzymes are involved in fluid secretion. Furthermore, in Rhodnius neglectus, proximal cells of Malpighian tubule exposed to hyperosmotic medium, regulate their volume through a mechanism called regulatory volume increase. This regulatory response involves inhibition of the (Na+ + K+ATPase activity that could lead to accumulation of active osmotic solute inside the cell, influx of water and return to the normal cell volume. Adenosine, a compound produced in stress conditions, also inhibits the (Na+ + K+ATPase activity. Taken together these data indicate that (Na+ + K+ATPase is a target of the regulatory mechanisms of water and ions transport responsible for homeostasis in Rhodnius sp.

Dynamic thermal baffle on lower head of FBR sodium-sodium intermediate heat exchanger

International Nuclear Information System (INIS)

Charbonnel, A.; Foussat, C.

1981-01-01

The cover head of the heat exchanger is bathed on the one side by the primary sodium of the 'cold' header of the vessel and on the other side by the secondary sodium which feeds the heat exchange tube bank through the lower tubesheet. In the case of transient or permanent operating conditions at partial ratings, there are large temperature differences between the inner sodium (inlet temperature conditions of secondary sodium) and the outer sodium (mean temperature conditions in the primary sodium outlet port), hence the necessity of designing a thermal baffle which protects the head and its connection to the tubesheet. A 'static' thermal baffle consisting of a thick steel plate enclosing static sodium around the head proves inadequate during transient operating conditions. This is why a 'dynamic' thermal baffle is used whose design is based on the fact that the primary sodium in the lower part of the outlet port is always at a temperature close to that of the secondary sodium in the inlet header and the head. The primary sodium is taken from the bottom of the outlet port by a ring deflector and circulates in an annulus created by a double housing and the head. It flows out through openings in the lower part of the housing. (orig./GL)

Crystal structure of the sodium-potassium pump (Na+,K+-ATPase) with bound potassium and ouabain

OpenAIRE

Ogawa, Haruo; Shinoda, Takehiro; Cornelius, Flemming; Toyoshima, Chikashi

2009-01-01

The sodium-potassium pump (Na+,K+-ATPase) is responsible for establishing Na+ and K+ concentration gradients across the plasma membrane and therefore plays an essential role in, for instance, generating action potentials. Cardiac glycosides, prescribed for congestive heart failure for more than 2 centuries, are efficient inhibitors of this ATPase. Here we describe a crystal structure of Na+,K+-ATPase with bound ouabain, a representative cardiac glycoside, at 2.8 Å resolution in a state analog...

NERATOOM work on pump development

International Nuclear Information System (INIS)

Hoornweg, C.J.

1976-01-01

The prototype pump has been manufactured by Stork Engineerings Works at Hengelo in 1969. The full-scale test on water has been carried out as part of the procedures of acceptance. Tests on sodium have been carried out in the pumptestfacility of Interatom at Bensberg (W. Germany); these tests started in March 1971 and were finished in October 1972. During that period nearly 6000 hours of pump testing were accomplished, of which 150 hours the pump was subjected to cavitation. During 30 hours the pump was subjected to a cavitation intensity of more than 3% loss of delivery head. At some occasions the loss of delivery head was 7%. The measured NPSH with the tests on sodium was 10m, whereas the NPSH obtained with the tests on water was 9m. Attempts have been made to account for this difference of NPSH-setting on the two liquids concerned. At the end of the tests on sodium (that is after the excecution of the cavitation tests) the delivery head of the pump was 2 m.l.c. less than the rated value. After dismantling the pump it appeared that the surface of the impeller vanes was roughened, especially at those parts where the original sand cast surface had not been polished. Based on the testresults and not being contradicted by calculation-results so far, our opinion is that cavitation in sodium of reactor temperature (550 0 C) most probably is of the same order of magnitude as it is in water of roomtemperature under the same conditions of NPSH, provided the same pump operates in systems that are exact replica of one another

The effect of pump cavitation on the design of the primary pumps for C.F.R

International Nuclear Information System (INIS)

Worster, R.C.

1976-01-01

In the design appraisal of the sodium pumps for the primary circuit of the proposed 1300 MW(e) CFR it has been recognised that cavitation, its effects and its control, is the outstanding hydraulic design problem. Careful consideration of this problem and of the possible effects of pump cavitation on the performance of other reactor systems has led to the conclusion that it is more prudent at present to specify pumps with zero cavitation at normal full speed operating conditions. Under abnormal operation it may be necessary to reduce the pumps' speed to prevent cavitation in the pumps or associated equipment. The principal reasons for this decision were uncertainties concerning the possibility of erosion due to limited cavitation in sodium and the possibility of pump cavitation noise interfering with acoustic detection of malfunctioning of reactor components or of boiling in the reactor core

Physical and Chemical Stability of Urapidil in 0.9% Sodium Chloride in Elastomeric Infusion Pump.

Science.gov (United States)

Tomasello, Cristina; Leggieri, Anna; Rabbia, Franco; Veglio, Franco; Baietto, Lorena; Fulcheri, Chiara; De Nicolò, Amedeo; De Perri, Giovanni; D'Avolio, Antonio

2016-01-01

Urapidil is an antihypertensive agent, usually administered through intravenous bolus injection, slow-intravenous infusion, or continuous-drug infusion by perfusor. Since to date no evidences are available on drug stability in elastomeric pumps, patients have to be hospitalized. The purpose of this study was to validate an ultra-performance liquid chromatographic method to evaluate urapidil stability in an elastomeric infusion pump, in order to allow continuous infusion as home-care treatment. Analyses were conducted by diluting urapidil in an elastomeric pump. Two concentrations were evaluated: 1.6 mg/mL and 3.3 mg/mL. For the analyses, a reverse-phase ultra-performance liquid chromatographic- photodiode array detection instrument was used. Stressed degradation, pH changes, and visual clarity were used as stability indicators up to 10 days after urapidil solution preparation. The drug showed no more than 5% degradation during the test period at room temperature. No pH changes and no evidences of incompatibility were observed. Stress tests resulted in appreciable observation of degradation products. Considering the observed mean values, urapidil hydrochloride in sodium chloride 0.9% in elastomeric infusion pumps is stable for at least 10 days. These results indicate that this treatment could be administered at home for a prolonged duration (at least 7 days) with a satisfactory response. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Cation depletion by the sodium pump in red cells with pathologic cation leaks. Sickle cells and xerocytes.

Science.gov (United States)

Joiner, C H; Platt, O S; Lux, S E

1986-12-01

The mechanism by which sickle cells and xerocytic red cells become depleted of cations in vivo has not been identified previously. Both types of cells exhibit elevated permeabilities to sodium and potassium, in the case of sickle cells, when deoxygenated. The ouabain-insensitive fluxes of sodium and potassium were equivalent, however, in both cell types under these conditions. When incubated 18 hours in vitro, sickle cells lost cations but only when deoxygenated. This cation depletion was blocked by ouabain, removal of external potassium, or pretreatment with 4,4'-diisothiocyanostilbene-2,2'-disulfonate, which blocks the increase in cation permeability induced by deoxygenation. The loss of cation exhibited by oxygenated xerocytes similarly incubated was also blocked by ouabain. These data support the hypothesis that the elevated "passive" cation fluxes of xerocytes and deoxygenated sickle cells are not directly responsible for cation depletion of these cells; rather, these pathologic leaks interact with the sodium pump to produce a net loss of cellular cation.

Cardiotonic steroids trigger non-classical testosterone signaling in Sertoli cells via the α4 isoform of the sodium pump.

Science.gov (United States)

Konrad, Lutz; Dietze, Raimund; Kirch, Ulrike; Kirch, Herbert; Eva, Alexander; Scheiner-Bobis, Georgios

2011-12-01

The α4 isoform of the Na(+),K(+)-ATPase (sodium pump) is known to be expressed in spermatozoa and to be critical for their motility. In the investigation presented here, we find that the rat-derived Sertoli cell line 93RS2 also expresses considerable amounts of the α4 isoform in addition to the α1 isoform. Since Sertoli cells are not motile, one can assume that the function of the α4 isoform in these cells must differ from that in spermatozoa. Thus, we assessed a potential involvement of this isoform in signaling pathways that are activated by the cardiotonic steroid (CTS) ouabain, a highly specific sodium pump ligand. Treatment of 93RS2 cells with ouabain leads to activation of the c-Src/c-Raf/Erk1/2 signaling cascade. Furthermore, we show for the first time that the activation of this cascade by ouabain results in phosphorylation and activation of the transcription factor CREB. This signaling cascade is induced at low nanomolar concentrations of ouabain, consistent with the involvement of the α4 isoform. This is further supported by experiments involving siRNA: silencing of α4 expression entirely blocks ouabain-induced activation of Erk1/2 whereas silencing of α1 has no effect. The findings of this study unveil new aspects in CTS/sodium pump interactions by demonstrating for the first time ouabain-induced signaling through the α4 isoform. The c-Src/c-Raf/Erk1/2/CREB cascade activated by ouabain is identical to the so-called non-classical signaling cascade that is normally triggered in Sertoli cells by testosterone. Taking into consideration that CTS are produced endogenously, our results may help to gain new insights into the physiological mechanisms associated with male fertility and reproduction. Copyright © 2011 Elsevier B.V. All rights reserved.

Driving Sodium-Potassium Pumps With An Oscillating Electric Field: Effects On Muscle Recovery In The Human Biceps Brachii

Science.gov (United States)

Bovyn, Matt; Chen, Wei; Lanes, Olivia; Mast, Jason

2013-03-01

Dr. Chen has developed a technique called synchronization modulation, which uses an oscillating electric field to increase the rate at which the sodium-potassium pumps in the cell membrane work. Because the sodium-potassium pump is integral in the recovery of skeletal muscle fibers after an action potential, we investigated the effects of applying synchronization modulation to muscles which had already undergone fatigue due to repeated action potentials during exercise. Fatigue was induced in human subjects' biceps brachii through isometric contraction. Surface electromyography measurements of fatigue index were used to quantify how the muscle recovered over the minutes following fatigue, both when synchronization modulation was applied and when it was absent. The preliminary results were inconclusive, but it is hoped that in later work it will be shown that applying synchronization modulation is effective in increasing the rate at which the muscle recovers to its initial state. This would demonstrate not only that synchronization modulation can be successfully applied to human muscle, but also that it has many potential applications in sports medicine and novel disease treatments. Work done as part of an REU program at the University of South Florida

The Grand Quevilly thermal test station - the SMW sodium circuit with a generator of superheated steam at 545 deg; Station d'essais thermiques de grand quevilly - circuit de sodium de 5 MW avec generateur de vapeur surchauffee a 545 deg

Energy Technology Data Exchange (ETDEWEB)

Robin, M G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

A 5 MW installation is described which is a reduced model of the heat exchange system of a sodium-cooled reactor. This plant, which is situated at Grand Quevilly (near Rouen), consists of: 1 - A primary sodium loop made up of a sodium re-heater running on heavy diesel oil, a mechanical pump and an intermediate exchanger made up of clusters of tubes fitted with baffles. 2 - A NaK(56 per cent of K) secondary loop consisting mainly of a mechanical pump and a double-wall steam generator with forced circulation and complete vaporization. 3 - A tertiary water loop consisting of the inside of the steam generator pipes, a pressure-reducing valve which cools down the super-heated fluid and acts as a turbine, a condenser, a charge-pump and a supply pump for the boiler. The heat is given finally to a water-source flowing into the Seine. Two important points of the installation are: - The water treatment unit - The control and regulation system Apart from the general satisfactory operation of the installation which it is hoped to obtain, a careful study will be made of the heat transmission coefficients of the important equipment such as the intermediate exchanger and the steam generator. The construction was finished on April 28, 1964. (author) [French] On decrit une installation de 5 MW figurant a echelle reduite un systeme de transfert de chaleur d'un reacteur refroidi au sodium. Cette installation, situee a Grand Quevilly (pres de Rouen) comprend: 1 - Une boucle de sodium primaire comportant un rechauffeur de sodium alimente en fuel lourd, une pompe mecanique et un echangeur intermediaire a faisceau tubulaire muni de chicanes, 2 - Une boucle de NaK (56% de K) secondaire dont les appareils principaux sont une pompe mecanique et un generateur de vapeur a double paroi, circulation forcee et vaporisation totale. 3 - une boucle tertiaire a eau comprenant l'interieur des tubes du generateur de vapeur, un detendeur-desurchauffeur simulant une turbine, un condenseur, une pompe de

Continuous analyzers of hydrogen and carbon in liquid sodium and of hydrocarbon total in protective atmosphere above sodium

International Nuclear Information System (INIS)

Pitak, O.; Fresl, M.

1980-01-01

The principle is described of a leak detector for detecting water penetration into sodium in a steam generator. The device operates as a diffusion H-meter with an ion pump. Ni or Fe diffusion diaphragm is washed with sodium while diffused hydrogen is pumped and also monitored with the ion pump. Another detector uses the principle of analyzing hydrocarbons in the cover gas above the sodium level. The carrier gas flow for the analyzer divided into measuring and reference parts is passed through a chamber housing the diffusion standard. For measuring carbon content in sodium, the detector analytical part may be completed with a chamber with moisturizing filling for scrubbing gas. Carbon passing through the diffusion Fe diaphragm is scrubbed on the inner wall in the form of CO which is reduced to methane and measured using the detector C-meter. (M.S.)

Crystal structure of the sodium-potassium pump

DEFF Research Database (Denmark)

Morth, J Preben; Pedersen, Bjørn Panyella; Toustrup-Jensen, Mads S

2007-01-01

The Na+,K+-ATPase generates electrochemical gradients for sodium and potassium that are vital to animal cells, exchanging three sodium ions for two potassium ions across the plasma membrane during each cycle of ATP hydrolysis. Here we present the X-ray crystal structure at 3.5 A resolution......-subunit is contained within a pocket between transmembrane helices and seems to be a novel regulatory element controlling sodium affinity, possibly influenced by the membrane potential. Udgivelsesdato: 2007-Dec-13...

A new concept for solar pumped lasers

Science.gov (United States)

Christiansen, W. H.

1978-01-01

A new approach is proposed in which an intermediate body heated by sunlight is used as the pumping source for IR systems, i.e., concentration solar radiation is absorbed and reradiated via an intermediate blackbody. This body is heated by focused sunlight to a high temperature and its heat losses are engineered to be small. The cooled laser tube (or tubes) is placed within the cavity and is pumped by it. The advantage is that the radiation spectrum is like a blackbody at the intermediate temperature and the laser medium selectively absorbs this light. Focusing requirements, heat losses, and absorption bandwidths of laser media are examined, along with energy balance and potential efficiency. The results indicate that for lasers pumped through an IR absorption spectrum, the use of an intermediate blackbody offers substantial and important advantages. The loss in radiative intensity for optical pumping by a lower-temperature body is partly compensated by the increased solid angle of exposure to the radiative environment.

Measurement of the Residual Sodium and Reaction Compounds on a Cleaned Cold Trap

International Nuclear Information System (INIS)

Kim, Byung Ho; Jeong, Ji Young; Kim, Jong Man; Choi, Byung Hae; Nam, Ho Yun Nam

2006-01-01

The purpose of a cleaning process is to remove the residual sodium adhering to the component walls once it has been properly drained. It is necessary to clean and decontaminate a component, especially the large components of the primary coolant system; such as the intermediate heat exchangers and the primary pump. Improper and inadequate cleaning has in a number of cases resulted in problems in the storage, handling, and reuse of components. Inadequate and incomplete removal of sodium results in residues which may contain metallic sodium and alkaline compounds such as sodium hydroxide, sodium oxide, sodium carbonate, and various types of alcoholates. Reinsertion of components containing these compounds into a high-temperature sodium system can result in either a intergranular penetration characteristic of a high-oxygen sodium or an accelerated corrosion due to oxygen. Cleaning methods are needed that will avoid a deleterious local overheating, material surface degradation or deposits, a chemical, physical, or mechanical damage, and external effects. It is important to determine the levels of residual sodium that can be accepted so that those deleterious effects will not negate the reuse of the component. The purpose of this paper is to measure the amount of the sodium and the reaction compounds remaining on a component after a cleaning and prepare acceptable criteria for the reuse of components which have been subjected to a sodium cleaning

Reactor having coolant recycling pump

International Nuclear Information System (INIS)

Goto, Tadashi; Karatsuka, Shigeki; Yamamoto, Hajime.

1991-01-01

In a coolant recycling pump for an LMFBR type reactor, vertical grooves are formed to a static portion which surrounds a pump shaft as far as the lower end thereof. Sodium mists present in an annular gap of the pump shaft form a rotational flow, lose its centrifugal force at the grooved portion and are collected positively to the grooved portion. Further, since the rotational flow in the grooved channel is in a state of a cavity flow, the pressure is released in the grooved portion and a secondary eddy current is formed thereby providing a depressurized state. Accordingly, by a synergestic effect of the centrifugal force and the cavity flow, sodium mists can be recovered completely. (T.M.)

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

Reactions between sodium and various carbon bearing compounds

Energy Technology Data Exchange (ETDEWEB)

Raine, A C; Thorley, A W [UKAEA, Risley, Warrington, Cheshire (United Kingdom)

1980-05-01

The presence of carbon bearing materials in liquid sodium is undesirable because of their ability to carburise stainless steel components. It has been demonstrated for example that carbon taken up by stainless steels can affect their mechanical properties and that thinner sectioned material such as fuel cladding and the tubing of intermediate heat exchanger may be more sensitive to such effects. Generally speaking, there are a number of potential carbon sources in reactor systems. Some of the sources such as the graphite in neutron shield rods, boron carbide in control rods and carbide fuels are part of the reactor designs while others such as oil in mechanical pumps arid 'coupling-fluids' used to inspect plant components are associated with the respective operation arid inspection of the plant. In this paper it is intended to discuss in general terms the way these various compounds behave in liquid sodium and to assess what effect their presence will have on the materials of construction in fast reactor systems. The paper also reviews the chemistry of the environment in relation to the types of carburizing species which may exist in sodium systems.

Thermo-electric pump

International Nuclear Information System (INIS)

Georges, J.-L.; Veyret, J.-F.

1973-01-01

Description is given of a thermo-pump for electrically conductive liquid fluids, e.g. for a liquid metal such as sodium. This pump is characterized in that the piping for the circulation of the conductive liquid is constituted by a plurality of conduits defined by two co-axial cylinders and two walls parallel to their axis. Each conduit limited outside by a magnet, inside by a mild-iron tube, and laterally by two materials forming a thermocouple. The electric current generated by that thermo-couple and the magnetic flux generated by the magnets both loop the loop through an outer cylindrical nickel shell. This can be applied to sodium circulation loops for testing nuclear fuel elements [fr

Operation and maintenance manual addendum to Westinghouse OMM-051-00-005 for intermediate-size inducer pump (ISIP) Model 266

International Nuclear Information System (INIS)

1979-01-01

This Addendum A to the Westinghouse Operation and Maintenance Manual OMM-051-00-005 contains additions, changes and deletions that modify data for the Liquid Metal Coolant Pump, Model LMP-1 to data applicable to the Rockwell International Intermediate-Size Inducer Pump (ISIP), Model 266. The major modifications on the ISIP are the new impeller/inducer assembly, diffuser vanes and new securing hardware. The paragraphs affected by Addendum A use the numbering system used in OMM-051-00-005 except each paragraph number is prefixed with an A preceding the paragraph number signifying that the paragraph is changed to conform with the ISIP configuration. Paragraphs within OMM-051-00-005 not identified in Addendum A remain unchanged with the data still valid and useable

Design and experimental characterization of an EM pump

International Nuclear Information System (INIS)

Kim, Hee Reyoung; Hong, Sang Hee

1999-01-01

Generally, an EM (electromagnetic) pump is been employed to circulate electrically conducting liquids by using the Lorentz force. Especially, at the liquid metal reactor (LMR), which uses liquid sodium with high electrical conductivity as a coolant, an EM pump is needed due to its advantages over a mechanical pump, such as no rotating parts, no noise, and simplicity. In this research, an EM pump of a pilot annular linear induction type with a flow rate of 200 l/min was designed by using the electrical equivalent-circuit method. The pump was designed and manufactured by considering material and environmental (high temperature and liquid sodium) requirements. The pump performance was experimentally characterized based on input currents, voltage, power, and frequency. Also, the theoretical prediction was compared with the experimental result

The Performance Estimation of PHTS Pump of DSFR

International Nuclear Information System (INIS)

Cho, Chungho; Han, Ji-Woong; Kim, Jong-Man; Cho, Youngil; Jung, Min-Hwan; Gam, Da-Young; Lee, Yong-bum; Jeong, Ji-Young

2015-01-01

In order to estimate the hydraulic behavior of the PHTS pump in sodium environment, model tests were conducted in water experimental facility by SAMJIN Industrial Co. before model tests using the STELLA-1 with sodium environment in 2015. STELLA-1 (Sodium inTegral Effect test Loop for safety simuLation and Assessment) is a large-scale separate effect test facility for demonstrating the thermal-hydraulic performances of major components such as a Sodium-to-Sodium heat exchanger (DHX), Sodium-to-Air heat exchanger (AHX) of the decay heat removal system, and mechanical sodium pump of the primary heat transport system (PHTS), which are important to ensure the safety of the sodium-cooled fast reactor (SFR). When the model and the prototype have the same the flow coefficient, to maintaining the dynamic similarity both model and prototype the non-dimensional coefficients to be simulated are head coefficient and power coefficient

Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

Energy Technology Data Exchange (ETDEWEB)

Barnes, M.J. [Westinghouse Savannah River Company, AIKEN, SC (United States); Peterson , R.A.

1998-04-01

The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variables on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation.

Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

International Nuclear Information System (INIS)

Barnes, M.J.; Peterson, R.A.

1998-04-01

The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variables on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation

An acoustic method for characterizing the onset of cavitation in nozzles and pumps

International Nuclear Information System (INIS)

Courbiere, P.

1984-12-01

The high sodium flow rates required by the reactor power rating have led to the use of sodium loop and pump designs in which a cavitation hazard exists. This paper discusses CEA test results on incipient cavitation, and examines pump impeller scale effects, sodium-water similitude criteria and the influence of the entrained gas content in the sodium flow

Mid-infrared picosecond pump-dump-probe and pump-repump-probe experiments to resolve a ground-state intermediate in cyanobacterial phytochrome Cph1.

Science.gov (United States)

van Wilderen, Luuk J G W; Clark, Ian P; Towrie, Michael; van Thor, Jasper J

2009-12-24

Multipulse picosecond mid-infrared spectroscopy has been used to study photochemical reactions of the cyanobacterial phytochrome photoreceptor Cph1. Different photophysical schemes have been discussed in the literature to describe the pathways after photoexcitation, particularly, to identify reaction phases that are linked to photoisomerisation and electronic decay in the 1566-1772 cm(-1) region that probes C=C and C=O stretching modes of the tetrapyrrole chromophore. Here, multipulse spectroscopy is employed, where, compared to conventional visible pump-mid-infrared probe spectroscopy, an additional visible pulse is incorporated that interacts with populations that are evolving on the excited- and ground-state potential energy surfaces. The time delays between the pump and the dump pulse are chosen such that the dump pulse interacts with different phases in the reaction process. The pump and dump pulses are at the same wavelength, 640 nm, and are resonant with the Pr ground state as well as with the excited state and intermediates. Because the dump pulse additionally pumps the remaining, partially recovered, and partially oriented ground-state population, theory is developed for estimating the fraction of excited-state molecules. The calculations take into account the model-dependent ground-state recovery fraction, the angular dependence of the population transfer resulting from the finite bleach that occurs with linearly polarized intense femtosecond optical excitation, and the partially oriented population for the dump field. Distinct differences between the results from the experiments that use a 1 or a 14 ps dump time favor a branching evolution from S1 to an excited state or reconfigured chromophore and to a newly identified ground-state intermediate (GSI). Optical dumping at 1 ps shows the instantaneous induced absorption of a delocalized C=C stretching mode at 1608 cm(-1), where the increased cross section is associated with the electronic ground

Intermediate energy electron scattering from sodium and potassium

International Nuclear Information System (INIS)

Buckman, S.J.

1979-06-01

This thesis describes an experimental investigation of the interaction of fast electrons with alkali metal atoms. Several of the theoretical models which have been applied to atomic collision processes including the first Born approximation, the Glauber approximation, the optical model and the distorted wave polarized orbital approximation are discussed. The theory of electron-photon coincidence experiments is outlined and the effects of fine and hyperfine structure on the polarization state of photons emitted from an excited atom are calculated for Sodium. The results of elastic scattering measurements on Sodium and Potassium are presented and used to test several theoretical models in their description of the differential cross section at incident energies between 50 and 200eV. Absolute differential and integrated total cross sections for the Potassium resonance lines and Sodium D-lines are presented. Results of the first electron-polarized photon coincidence experiment on the Sodium D-lines are presented and compared with available theoretical calculations

Regulation of the sodium-potassium pump in cultured rat skeletal myotubes by intracellular sodium ions

International Nuclear Information System (INIS)

Brodie, C.; Sampson, S.R.

1989-01-01

The properties of the Na-K pump and some of the factors controlling its amount and function were studied in rat myotubes in culture. The number of Na-K pump sites was quantified by measuring the amount of [ 3 H]ouabain bound to whole-cell preparations. Activity of the pump was determined by measurement of ouabain-sensitive 86 Rb-uptake and component of membrane potential. Chronic treatment of myotubes with tetrodotoxin (TTX), which lowers [Na]i, decreased the number of Na-K pumps, the ouabain-sensitive 86Rb uptake, and the size of the electrogenic pump component of Em. In contrast, chronic treatment with either ouabain or veratridine, which increases [Na+]i, resulted in an elevated level of Na-K pump sites. This effect was blocked by inhibitors of protein synthesis. Neither rates of degradation nor affinity of pump sites in cells treated with TTX, veratridine, or ouabain differred from those in control cells. The number and activity of Na-K pump sites were unaffected by chronic elevation in [Ca]i or chronic depolarization. We conclude that alterations in the level in intracellular Na ions play the major role in regulation of Na-K pump synthesis in cultured mammalian skeletal muscle

Robust remote-pumping sodium laser for advanced LIDAR and guide star applications

Science.gov (United States)

Ernstberger, Bernhard; Enderlein, Martin; Friedenauer, Axel; Schwerdt, Robin; Wei, Daoping; Karpov, Vladimir; Leisching, Patrick; Clements, Wallace R. L.; Kaenders, Wilhelm G.

2015-10-01

The performance of large ground-based optical telescopes is limited due to wavefront distortions induced by atmospheric turbulence. Adaptive optics systems using natural guide stars with sufficient brightness provide a practical way for correcting the wavefront errors by means of deformable mirrors. Unfortunately, the sky coverage of bright stars is poor and therefore the concept of laser guide stars was invented, creating an artificial star by exciting resonance fluorescence from the mesospheric sodium layer about 90 km above the earth's surface. Until now, mainly dye lasers or sumfrequency mixing of solid state lasers were used to generate laser guide stars. However, these kinds of lasers require a stationary laser clean room for operation and are extremely demanding in maintenance. Under a development contract with the European Southern Observatory (ESO) and W. M. Keck Observatory (WMKO), TOPTICA Photonics AG and its partner MPB Communications have finalized the development of a next-generation sodium guide star laser system which is available now as a commercial off-the-shelf product. The laser is based on a narrow-band diode laser, Raman fiber amplifier (RFA) technology and resonant second-harmonic generation (SHG), thus highly reliable and simple to operate and maintain. It emits > 22 W of narrow-linewidth (≈ 5 MHz) continuous-wave radiation at sodium resonance and includes a re-pumping scheme for boosting sodium return flux. Due to the SHG resonator acting as spatial mode filter and polarizer, the output is diffraction-limited with RMS wavefront error concept of line-replaceable units (LRU). A comprehensive system software, as well as an intuitive service GUI, allow for remote control and error tracking down to at least the LRU level. In case of a failure, any LRU can be easily replaced. With these fiber-based guide star lasers, TOPTICA for the first time offers a fully engineered, off-the-shelf guide star laser system for groundbased optical telescopes

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

Utilization of large electromagnetic pumps in the fast breeder reactors

International Nuclear Information System (INIS)

Deverge, C.; Lefrere, J.P.; Peturaud, P.; Sauvage, M.

1984-04-01

After an overview concerning the induction annular electromagnetic pumps and the dimensioning methods usually utilized, development of these components for a fast breeder integrated reactor is considered: - utilization of cooled EMP in the intermediate circuit, - utilization of immersed pumps, coupled with the intermediate exchanger, for the primary pumping; dimensioning, energetic aspects, and effects on the power plant geometrical configurations [fr

Cavitation erosion in sodium flow, sodium cavitation tunnel testing

International Nuclear Information System (INIS)

Courbiere, Pierre.

1981-04-01

The high-volume sodium flows present in fast neutron reactors are liable to induce cavitation phenomena in various portion of the sodium lines and pumps. The absence of sufficient data in this area led the C.E.A. to undertake an erosion research program in cavitating sodium flow. This paper discusses the considerations leading to the definition and execution of sodium cavitation erosion tests, and reviews the tests run with 400 0 C sodium on various steel grades: 316, 316 L, 316 Ti (Z8CNDT17-12), Poral (Z3CND18-12), 304 L and LN2 - clad 316 L (Ni coating-clad 316 L). Acoustic detection and signal processing methods were used with an instrument package designed and implemented at the Cadarache Nuclear Research Center

Intermediate-scale sodium-concrete reaction tests with basalt and limestone concrete

International Nuclear Information System (INIS)

Hassberger, J.A.; Muhlestein, L.D.

1981-01-01

Ten tests were performed to investigate the chemical reactions and rate and extent of attack between sodium and basalt and limestone concretes. Test temperatures ranged from 510 to 870 0 C (950 to 1600 0 F) and test times from 2 to 24 hours. Sodium hydroxide was added to some of the tests to assess the impact of a sodium hydroxide-aided reaction on the overall penetration characteristics. Data suggest that the sodium penetration of concrete surfaces is limited. Penetration of basalt concrete in the presence of sodium hydroxide is shown to be less severe than attack by the metallic sodium alone. Presence of sodium hydroxide changes the characteristics of sodium penetration of limestone concrete, but no major differences in bulk penetration were observed as compared to penetration by metallic sodium

Fast breeder reactor electromagnetic pump

International Nuclear Information System (INIS)

Araseki, Hideo; Murakami, Takahiro

2008-01-01

Main pumps circulating sodium in the FBR type reactor have been mechanical types, not electromagnetic pumps. Electromagnetic pump of 1-2 m 3 /min has been used as an auxiliary pump. Large sized electromagnetic pumps such as several hundred m 3 /min have not been commercialized due to technical difficulties with electromagnetic instability and pressure pulsations. This article explained electromagnetic and fluid equations and magnetic Reynolds number related with electromagnetic pumps and numerical analysis of instability characteristics and pressure pulsations and then described applications of the results to FBR system. Magnetic Reynolds number must be chosen less than one with appropriate operating frequency and optimum slip of 0.2-0.4. (T. Tanaka)

Possible involvement of membrane lipids peroxidation and oxidation of catalytically essential thiols of the cerebral transmembrane sodium pump as component mechanisms of iron-mediated oxidative stress-linked dysfunction of the pump's activity

Directory of Open Access Journals (Sweden)

T.I. Omotayo

2015-04-01

Full Text Available The precise molecular events defining the complex role of oxidative stress in the inactivation of the cerebral sodium pump in radical-induced neurodegenerative diseases is yet to be fully clarified and thus still open. Herein we investigated the modulation of the activity of the cerebral transmembrane electrogenic enzyme in Fe2+-mediated in vitro oxidative stress model. The results show that Fe2+ inhibited the transmembrane enzyme in a concentration dependent manner and this effect was accompanied by a biphasic generation of aldehydic product of lipid peroxidation. While dithiothreitol prevented both Fe2+ inhibitory effect on the pump and lipid peroxidation, vitamin E prevented only lipid peroxidation but not inhibition of the pump. Besides, malondialdehyde (MDA inhibited the pump by a mechanism not related to oxidation of its critical thiols. Apparently, the low activity of the pump in degenerative diseases mediated by Fe2+ may involve complex multi-component mechanisms which may partly involve an initial oxidation of the critical thiols of the enzyme directly mediated by Fe2+ and during severe progression of such diseases; aldehydic products of lipid peroxidation such as MDA may further exacerbate this inhibitory effect by a mechanism that is likely not related to the oxidation of the catalytically essential thiols of the ouabain-sensitive cerebral electrogenic pump.

Adoption of nitrogen power conversion system for small scale ultra-long cycle fast reactor eliminating intermediate sodium loop

International Nuclear Information System (INIS)

Seo, Seok Bin; Seo, Han; Bang, In Cheol

2016-01-01

Highlights: • N 2 power conversion system for both safety and thermal performance aspects. • Sensitivity studies of several controlled parameters on N 2 power conversion system. • The elimination of the intermediate loop increased the cycle thermal efficiency. • The elimination of the intermediate loop expects economic advantages. - Abstract: As one of SFRs, the ultra-long cycle fast reactor with a power rating of 100 MW e (UCFR-100) was introduced for a 60-year operation. As an alternative to the traditional steam Rankine cycle for the power conversion system, gas based Brayton cycle has been considered for UCFR-100. Among Supercritical CO 2 (S-CO 2 ), Helium (He), Nitrogen (N 2 ) as candidates for the power conversion system for UCFR-100, an N 2 power conversion system was chosen considering both safety and thermal performance aspects. The elimination of the intermediate sodium loop could be achieved due to the safety and stable characteristics of nitrogen working fluid. In this paper, sensitivity studies with respect to several controlled parameters on N 2 power conversion system were performed to optimize the system. Furthermore, the elimination of the intermediate loop was evaluated with respect to its impact on the thermodynamic performance and other aspects.

Learning from jellyfish: Fluid transport in muscular pumps at intermediate Reynolds numbers

Science.gov (United States)

Nawroth, Janna; Dabiri, John

2010-11-01

Biologically inspired hydrodynamic propulsion and maneuvering strategies promise the advancement of medical implants and minimally invasive clinical tools. We have chosen juvenile jellyfish as a model system for investigating fluid dynamics and morphological properties underlying fluid transport by a muscular pump at intermediate Reynolds numbers. Recently we have described how natural variations in viscous forces are balanced by changes in jellyfish body shape (phenotypic plasticity), to the effect of facilitating efficient body-fluid interaction. Complementing these studies in our live model organisms, we are also engaged in engineering an artificial jellyfish, that is, a jellyfish-inspired construct of a flexible plastic sheet actuated by a monolayer of rat cardiomyocytes. The main challenges here are (1) to derive a body shape and deformation suitable for effective fluid transport under physiological conditions, (2) to understand the mechanical properties of the muscular film and derive a design capable of the desired deformation, (3) to master the proper alignment and timely contraction of the muscle component needed to achieve the desired deformation, and (4) to evaluate the performance of the design.

Cardiac glycoside ouabain induces activation of ATF-1 and StAR expression by interacting with the α4 isoform of the sodium pump in Sertoli cells.

Science.gov (United States)

Dietze, Raimund; Konrad, Lutz; Shihan, Mazen; Kirch, Ulrike; Scheiner-Bobis, Georgios

2013-03-01

Sertoli cells express α1 and α4 isoforms of the catalytic subunit of Na(+),K(+)-ATPase (sodium pump). Our recent findings demonstrated that interactions of the α4 isoform with cardiotonic steroids (CTS) like ouabain induce signaling cascades that resemble the so-called non-classical testosterone pathway characterized by activation of the c-Src/c-Raf/Erk1/2/CREB signaling cascade. Here we investigate a possible physiological significance of the activated cascade. The results obtained in the current investigation show that the ouabain-induced signaling cascade also leads to the activation of the CREB-related activating transcription factor 1 (ATF-1) in the Sertoli cell line 93RS2 in a concentration- and time-dependent manner, as demonstrated by detection of ATF-1 phosphorylated on Ser63 in western blots. The ouabain-activated ATF-1 protein was found to localize to the cell nuclei. The sodium pump α4 isoform mediates this activation, as it is ablated when cells are incubated with siRNA to the α4 isoform. Ouabain also leads to increased expression of steroidogenic acute regulator (StAR) protein, which has been shown to be a downstream consequence of CREB/ATF-1 activation. Taking into consideration that CTS are most likely produced endogenously, the demonstrated induction of StAR expression by ouabain establishes a link between CTS, the α4 isoform of the sodium pump, and steroidogenesis crucial for male fertility and reproduction. Copyright © 2012 Elsevier B.V. All rights reserved.

Control of reactor coolant flow path during reactor decay heat removal

Science.gov (United States)

Hunsbedt, Anstein N.

1988-01-01

An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.

Control of concerted two bond versus single bond dissociation in CH3Co(CO)4 via an intermediate state using pump-dump laser pulses

Science.gov (United States)

Ambrosek, David; González, Leticia

2007-10-01

Wavepacket propagations on ab initio multiconfigurational two-dimensional potential energy surfaces for CH3Co(CO)4 indicate that after irradiation to the lowest first and second electronic excited states, concerted dissociation of CH3 and the axial CO ligand takes place. We employ a pump-dump sequence of pulses with appropriate frequencies and time delays to achieve the selective breakage of a single bond by controlling the dissociation angle. The pump and dump pulse sequence exploits the unbound surface where dissociation occurs in a counterintuitive fashion; stretching of one bond in an intermediate state enhances the single dissociation of the other bond.

Control of concerted two bond versus single bond dissociation in CH(3)Co(CO)(4) via an intermediate state using pump-dump laser pulses.

Science.gov (United States)

Ambrosek, David; González, Leticia

2007-10-07

Wavepacket propagations on ab initio multiconfigurational two-dimensional potential energy surfaces for CH(3)Co(CO)(4) indicate that after irradiation to the lowest first and second electronic excited states, concerted dissociation of CH(3) and the axial CO ligand takes place. We employ a pump-dump sequence of pulses with appropriate frequencies and time delays to achieve the selective breakage of a single bond by controlling the dissociation angle. The pump and dump pulse sequence exploits the unbound surface where dissociation occurs in a counterintuitive fashion; stretching of one bond in an intermediate state enhances the single dissociation of the other bond.

Sodium-cooled nuclear reactor

International Nuclear Information System (INIS)

Hammers, H.W.

1982-01-01

The invention concerns a sodium-cooled nuclear reactor, whose reactor tank contains the primary circuit, shielding surrounding the reactor core and a primary/secondary heat exchanger, particularly a fast breeder reactor on the module principle. In order to achieve this module principle it is proposed to have electromagnetic circulating pumps outside the reactor tank, where the heat exchanger is accomodated in an annular case above the pumps. This case has several openings at the top end to the space above the reactor core, some smaller openings in the middle to the same space and is connected at the bottom to an annular space between the tank wall and the reactor core. As a favoured variant, it is proposed that the annular electromagnetic pumps should be arranged concentrically to the reactor tank, where there is an annual duct on the inside of the reactor tank. In this way the sodium-cooled nuclear reactor is made suitable as a module with a large number of such elements. (orig.) [de

Na/K pump regulation of cardiac repolarization: insights from a systems biology approach

KAUST Repository

Bueno-Orovio, Alfonso

2013-05-15

The sodium-potassium pump is widely recognized as the principal mechanism for active ion transport across the cellular membrane of cardiac tissue, being responsible for the creation and maintenance of the transarcolemmal sodium and potassium gradients, crucial for cardiac cell electrophysiology. Importantly, sodium-potassium pump activity is impaired in a number of major diseased conditions, including ischemia and heart failure. However, its subtle ways of action on cardiac electrophysiology, both directly through its electrogenic nature and indirectly via the regulation of cell homeostasis, make it hard to predict the electrophysiological consequences of reduced sodium-potassium pump activity in cardiac repolarization. In this review, we discuss how recent studies adopting the systems biology approach, through the integration of experimental and modeling methodologies, have identified the sodium-potassium pump as one of the most important ionic mechanisms in regulating key properties of cardiac repolarization and its rate dependence, from subcellular to whole organ levels. These include the role of the pump in the biphasic modulation of cellular repolarization and refractoriness, the rate control of intracellular sodium and calcium dynamics and therefore of the adaptation of repolarization to changes in heart rate, as well as its importance in regulating pro-arrhythmic substrates through modulation of dispersion of repolarization and restitution. Theoretical findings are consistent across a variety of cell types and species including human, and widely in agreement with experimental findings. The novel insights and hypotheses on the role of the pump in cardiac electrophysiology obtained through this integrative approach could eventually lead to novel therapeutic and diagnostic strategies. © 2013 Springer-Verlag Berlin Heidelberg.

Na/K pump regulation of cardiac repolarization: insights from a systems biology approach.

Science.gov (United States)

Bueno-Orovio, Alfonso; Sánchez, Carlos; Pueyo, Esther; Rodriguez, Blanca

2014-02-01

The sodium-potassium pump is widely recognized as the principal mechanism for active ion transport across the cellular membrane of cardiac tissue, being responsible for the creation and maintenance of the transarcolemmal sodium and potassium gradients, crucial for cardiac cell electrophysiology. Importantly, sodium-potassium pump activity is impaired in a number of major diseased conditions, including ischemia and heart failure. However, its subtle ways of action on cardiac electrophysiology, both directly through its electrogenic nature and indirectly via the regulation of cell homeostasis, make it hard to predict the electrophysiological consequences of reduced sodium-potassium pump activity in cardiac repolarization. In this review, we discuss how recent studies adopting the systems biology approach, through the integration of experimental and modeling methodologies, have identified the sodium-potassium pump as one of the most important ionic mechanisms in regulating key properties of cardiac repolarization and its rate dependence, from subcellular to whole organ levels. These include the role of the pump in the biphasic modulation of cellular repolarization and refractoriness, the rate control of intracellular sodium and calcium dynamics and therefore of the adaptation of repolarization to changes in heart rate, as well as its importance in regulating pro-arrhythmic substrates through modulation of dispersion of repolarization and restitution. Theoretical findings are consistent across a variety of cell types and species including human, and widely in agreement with experimental findings. The novel insights and hypotheses on the role of the pump in cardiac electrophysiology obtained through this integrative approach could eventually lead to novel therapeutic and diagnostic strategies.

Electromagnetic pump

International Nuclear Information System (INIS)

Ito, Koji; Suetake, Norio; Aizawa, Toshie; Nakasaki, Masayoshi

1998-01-01

The present invention provides an electromagnetic pump suitable to a recycling pump for liquid sodium as coolants of an FBR type reactor. Namely, a stator module of the electromagnetic pump of the present invention comprises a plurality of outer laminate iron core units and outer stator modules stacked alternately in the axial direction. With such a constitution, even a long electromagnetic pump having a large number of outer stator coils can be manufactured without damaging electric insulation of the outer stator coils. In addition, the inner circumferential surface of the outer laminate iron cores is urged and brought into contact with the outer circumferential surface of the outer duct by an elastic material. With such a constitution, Joule loss heat generated in the outer stator coils and internal heat generated in the outer laminate iron cores can be released to an electroconductive fluid flowing the inner circumference of the outer duct by way of the outer duct. (I.S.)

Spontaneous excitation patterns computed for axons with injury-like impairments of sodium channels and Na/K pumps.

Directory of Open Access Journals (Sweden)

Na Yu

Full Text Available In injured neurons, "leaky" voltage-gated sodium channels (Nav underlie dysfunctional excitability that ranges from spontaneous subthreshold oscillations (STO, to ectopic (sometimes paroxysmal excitation, to depolarizing block. In recombinant systems, mechanical injury to Nav1.6-rich membranes causes cytoplasmic Na(+-loading and "Nav-CLS", i.e., coupled left-(hyperpolarizing-shift of Nav activation and availability. Metabolic injury of hippocampal neurons (epileptic discharge results in comparable impairment: left-shifted activation and availability and hence left-shifted I(Na-window. A recent computation study revealed that CLS-based I(Na-window left-shift dissipates ion gradients and impairs excitability. Here, via dynamical analyses, we focus on sustained excitability patterns in mildly damaged nodes, in particular with more realistic Gaussian-distributed Nav-CLS to mimic "smeared" injury intensity. Since our interest is axons that might survive injury, pumps (sine qua non for live axons are included. In some simulations, pump efficacy and system volumes are varied. Impacts of current noise inputs are also characterized. The diverse modes of spontaneous rhythmic activity evident in these scenarios are studied using bifurcation analysis. For "mild CLS injury", a prominent feature is slow pump/leak-mediated E(Ion oscillations. These slow oscillations yield dynamic firing thresholds that underlie complex voltage STO and bursting behaviors. Thus, Nav-CLS, a biophysically justified mode of injury, in parallel with functioning pumps, robustly engenders an emergent slow process that triggers a plethora of pathological excitability patterns. This minimalist "device" could have physiological analogs. At first nodes of Ranvier and at nociceptors, e.g., localized lipid-tuning that modulated Nav midpoints could produce Nav-CLS, as could co-expression of appropriately differing Nav isoforms.

Degradation of the drug sodium diclofenac by Trametes versicolor pellets and identification of some intermediates by NMR

Energy Technology Data Exchange (ETDEWEB)

Marco-Urrea, Ernest [Departament d' Enginyeria Quimica and Institut de Ciencia i Tecnologia Ambiental, Escola d' Enginyeria (Estonia), Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra (Spain); Perez-Trujillo, Miriam [Servei de Ressonancia Magnetica Nuclear, UAB, 08193 Bellaterra (Spain); Cruz-Morato, Carles [Departament d' Enginyeria Quimica and Institut de Ciencia i Tecnologia Ambiental, Escola d' Enginyeria (Estonia), Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra (Spain); Caminal, Gloria, E-mail: gloria.caminal@uab.es [Unitat de Biocatalisis Aplicada associada al IQAC (CSIC-UAB), EE, UAB, 08193 Bellaterra (Spain); Vicent, Teresa [Departament d' Enginyeria Quimica and Institut de Ciencia i Tecnologia Ambiental, Escola d' Enginyeria (Estonia), Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra (Spain)

2010-04-15

Degradation of diclofenac sodium, a nonsteroidal anti-inflammatory drug widely found in the aquatic environment, was assessed using the white-rot fungus Trametes versicolor. Almost complete diclofenac removal ({>=}94%) occurred the first hour with T. versicolor pellets when the drug was added at relatively high (10 mg L{sup -1}) and environmentally relevant low (45 {mu}g L{sup -1}) concentrations in a defined liquid medium. In vivo and in vitro experiments using the cytochrome P450 inhibitor 1-aminobenzotriazole and purified laccase, respectively, suggested at least two different mechanisms employed by T. versicolor to initiate diclofenac degradation. Two hydroxylated metabolites, 4'-hydroxydiclofenac and 5-hydroxydiclofenac, were structurally elucidated by nuclear magnetic resonance as degradation intermediates in fungal cultures spiked with diclofenac. Both parent compound and intermediates disappeared after 24 h leading to a decrease in ecotoxicity calculated by the Microtox test. Laccase-catalyzed transformation of diclofenac led to the formation of 4-(2,6-dichlorophenylamino)-1,3-benzenedimethanol, which was not detected in in vivo experiments probably due to the low laccase activity levels observed through the first hours of incubation.

Degradation of the drug sodium diclofenac by Trametes versicolor pellets and identification of some intermediates by NMR

International Nuclear Information System (INIS)

Marco-Urrea, Ernest; Perez-Trujillo, Miriam; Cruz-Morato, Carles; Caminal, Gloria; Vicent, Teresa

2010-01-01

Degradation of diclofenac sodium, a nonsteroidal anti-inflammatory drug widely found in the aquatic environment, was assessed using the white-rot fungus Trametes versicolor. Almost complete diclofenac removal (≥94%) occurred the first hour with T. versicolor pellets when the drug was added at relatively high (10 mg L -1 ) and environmentally relevant low (45 μg L -1 ) concentrations in a defined liquid medium. In vivo and in vitro experiments using the cytochrome P450 inhibitor 1-aminobenzotriazole and purified laccase, respectively, suggested at least two different mechanisms employed by T. versicolor to initiate diclofenac degradation. Two hydroxylated metabolites, 4'-hydroxydiclofenac and 5-hydroxydiclofenac, were structurally elucidated by nuclear magnetic resonance as degradation intermediates in fungal cultures spiked with diclofenac. Both parent compound and intermediates disappeared after 24 h leading to a decrease in ecotoxicity calculated by the Microtox test. Laccase-catalyzed transformation of diclofenac led to the formation of 4-(2,6-dichlorophenylamino)-1,3-benzenedimethanol, which was not detected in in vivo experiments probably due to the low laccase activity levels observed through the first hours of incubation.

Annual report 1974. Sodium technology development programme

International Nuclear Information System (INIS)

1975-01-01

The sodium technology development program comprises a number of separate research programs in the field of designing and testing parts and components for the SNR-300 reactor. Design studies and theoretical studies on cold trapping and the behavior of hydrogen in sodium circuits are reported. A preliminary test program for fighting sodium fires is completed. Results of research done on vibration measurements and counter-current mixing in a dummy tube bundle of a S.N.R. spiralized steam generator with counter-current flow are reported briefly. Research done in the field of heat transfer, pressure drop and bubble dynamics of a straight pipe steam generator are also briefly reported. To determine the influence of spiral diameter of the spiralized pipe on heat transfer in a spiralized pipe heat exchanger, a second testsection will be built in 1975. Research was reported on pump viscoseals, bearing stability, rotordynamics and bearing materials for sodium pumps. Research done on the properties of SNR-construction materials at high temperature and long time exposure and corrosion in sodium are reported. Fundamental research on corrosion accompanied this research. The report closes with results of weldability, mechanized-welding and remote welding of sodium-wetted surfaces

Thermal energy storage using thermo-chemical heat pump

International Nuclear Information System (INIS)

Hamdan, M.A.; Rossides, S.D.; Haj Khalil, R.

2013-01-01

Highlights: ► Understanding of the performance of thermo chemical heat pump. ► Tool for storing thermal energy. ► Parameters that affect the amount of thermal stored energy. ► Lithium chloride has better effect on storing thermal energy. - Abstract: A theoretical study was performed to investigate the potential of storing thermal energy using a heat pump which is a thermo-chemical storage system consisting of water as sorbet, and sodium chloride as the sorbent. The effect of different parameters namely; the amount of vaporized water from the evaporator, the system initial temperature and the type of salt on the increase in temperature of the salt was investigated and hence on the performance of the thermo chemical heat pump. It was found that the performance of the heat pump improves with the initial system temperature, with the amount of water vaporized and with the water remaining in the system. Finally it was also found that lithium chloride salt has higher effect on the performance of the heat pump that of sodium chloride.

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

Pump-dump-probe and pump-repump-probe ultrafast spectroscopy resolves cross section of an early ground state intermediate and stimulated emission in the photoreactions of the Pr ground state of the cyanobacterial phytochrome Cph1.

Science.gov (United States)

Fitzpatrick, Ann E; Lincoln, Craig N; van Wilderen, Luuk J G W; van Thor, Jasper J

2012-01-26

The primary photoreactions of the red absorbing ground state (Pr) of the cyanobacterial phytochrome Cph1 from Synechocystis PCC 6803 involve C15═C16 Z-E photoisomerization of its phycocyanobilin chromophore. The first observable product intermediate in pump-probe measurements of the photocycle, "Lumi-R", is formed with picosecond kinetics and involves excited state decay reactions that have 3 and 14 ps time constants. Here, we have studied the photochemical formation of the Lumi-R intermediate using multipulse picosecond visible spectroscopy. Pump-dump-probe (PDP) and pump-repump-probe (PRP) experiments were carried out by employing two femtosecond visible pulses with 1, 14, and 160 ps delays, together with a broadband dispersive visible probe. The time delays between the two excitation pulses have been selected to allow interaction with the dominant (3 and 14 ps) kinetic phases of Lumi-R formation. The frequency dependence of the PDP and PRP amplitudes was investigated at 620, 640, 660, and 680 nm, covering excited state absorption (λ(max) = 620 nm), ground state absorption (λ(max) = 660 nm), and stimulated emission (λ(max) = 680 nm) cross sections. Experimental double difference transient absorbance signals (ΔΔOD), from the PDP and PRP measurements, required corrections to remove contributions from ground state repumping. The sensitivity of the resulting ΔΔOD signals was systematically investigated for possible connectivity schemes and photochemical parameters. When applying a homogeneous (sequentially decaying) connectivity scheme in both the 3 and 14 ps kinetic phases, evidence for repumping of an intermediate that has an electronic ground state configuration (GSI) is taken from the dump-induced S1 formation with 620, 640, and 660 nm wavelengths and 1 and 14 ps repump delays. Evidence for repumping a GSI is also seen, for the same excitation wavelengths, when imposing a target connectivity scheme proposed in the literature for the 1 ps repump delay. In

Aspartic acid 397 in subunit B of the Na+-pumping NADH:quinone oxidoreductase from Vibrio cholerae forms part of a sodium-binding site, is involved in cation selectivity, and affects cation-binding site cooperativity.

Science.gov (United States)

Shea, Michael E; Juárez, Oscar; Cho, Jonathan; Barquera, Blanca

2013-10-25

The Na(+)-pumping NADH:quinone complex is found in Vibrio cholerae and other marine and pathogenic bacteria. NADH:ubiquinone oxidoreductase oxidizes NADH and reduces ubiquinone, using the free energy released by this reaction to pump sodium ions across the cell membrane. In a previous report, a conserved aspartic acid residue in the NqrB subunit at position 397, located in the cytosolic face of this protein, was proposed to be involved in the capture of sodium. Here, we studied the role of this residue through the characterization of mutant enzymes in which this aspartic acid was substituted by other residues that change charge and size, such as arginine, serine, lysine, glutamic acid, and cysteine. Our results indicate that NqrB-Asp-397 forms part of one of the at least two sodium-binding sites and that both size and charge at this position are critical for the function of the enzyme. Moreover, we demonstrate that this residue is involved in cation selectivity, has a critical role in the communication between sodium-binding sites, by promoting cooperativity, and controls the electron transfer step involved in sodium uptake (2Fe-2S → FMNC).

Report of sodium cavitation

International Nuclear Information System (INIS)

Murai, Hitoshi; Shima, Akira; Oba, Toshisaburo; Kobayashi, Ryoji; Hashimoto, Hiroyuki

1975-01-01

The damage of components for LMFBRs due to sodium cavitation is serious problem. This report summarizes the following items, (1) mechanism of the incipience of sodium cavitation, (2) damage due to sodium cavitation, (3) detection method for sodium cavitation, and (4) estimation method for sodium cavitation by the comparison with water cavitation. Materials were collected from the reports on liquid metal cavitation, sodium cavitation and water cavitation published from 1965 to now. The mechanism of the incipience of sodium cavitation cavitation parameters (mean location, distributed amount or occurrence aspect and stability), experiment of causing cavitation with Venturi tube, and growth of bubbles within superheated sodium. The sodium cavitation damage was caused by magnetostriction vibration method and with Venturi tube. The state of damage was investigated with the cavitation performance of a sodium pump, and the damage was examined in view of the safety of LMFBR plants. Sodium cavitation was detected with acoustic method, radiation method, and electric method. The effect of physical property of liquid on incipient cavitation was studied. These are thermodynamic effect based on quasistatic thermal equilibrium condition and the effect of the physical property of liquid based on bubble dynamics. (Iwase, T.)

Assessment of flow induced vibration in a sodium-sodium heat exchanger

Energy Technology Data Exchange (ETDEWEB)

Prakash, V. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India)], E-mail: prakash@igcar.gov.in; Thirumalai, M.; Prabhakar, R.; Vaidyanathan, G. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India)

2009-01-15

The 500 MWe Prototype Fast Breeder Reactor (PFBR) is under construction at Kalpakkam. It is a liquid metal sodium cooled pool type fast reactor with all primary components located inside a sodium pool. The heat produced due to fission in the core is transported by primary sodium to the secondary sodium in a sodium to sodium Intermediate Heat Exchanger (IHX), which in turn is transferred to water in the steam generator. PFBR IHX is a shell and tube type heat exchanger with primary sodium on shell side and secondary sodium in the tube side. Since IHX is one of the critical components placed inside the radioactive primary sodium, trouble-free operation of the IHX is very much essential for power plant availability. To validate the design and the adequacy of the support system provided for the IHX, flow induced vibration (FIV) experiments were carried out in a water test loop on a 60 deg. sector model. This paper discusses the flow induced vibration measurements carried out in 60 deg. sector model of IHX, the modeling criteria, the results and conclusion.

Pump/heat exchanger assembly for pool-type reactor

International Nuclear Information System (INIS)

Nathenson, R.D.; Slepian, R.M.

1987-01-01

A heat exchanger and pump assembly comprising a heat exchanger including a housing for defining an annularly shaped cavity and supporting therein a plurality of heat transfer tubes. A pump is disposed beneath the heat exchanger and is comprised of a plurality of flow couplers disposed in a circular array. Each flow coupler is comprised of a pump duct for receiving a first electrically conductive fluid, i.e. the primary liquid metal, from a pool thereof, and a generator duct for receiving a second electrically conductive fluid, i.e. the intermediate liquid metal. The primary liquid metal is introduced from the reactor pool into the top, inlet ends of the tubes, flowing downward therethrough to be discharged from the tubes' bottom ends directly into the reactor pool. The primary liquid metal is variously introduced into the pump ducts directly from the reactor pool, either from the bottom or top end of the flow coupler. The intermediate fluid introduced into the generator ducts via the inlet duct and inlet plenum and after leaving the generator ducts passes through the annular cavity of the exchanger to cool the primary liquid in the tubes. The annular magnetic field of the pump is produced by a circular array of electromagnets having hollow windings cooled by a flow of the intermediate metal. (author)

Fabrication and testing of main sodium pumps of Superphenix 1

International Nuclear Information System (INIS)

Noel, H.; Pasqualini, G.

1985-01-01

The complexity of the loads involved and the extremely fine analysis required necessitates extensive design calculations for the Superphenix 1 primary and secondary pumps and associated expansion tanks, aiming toward detailed design validation, after slight adjustments, mainly to the secondary pumps and expansion tanks. The component parts to be built were far larger than those for the previous pumps (Rapsodie, Phenix), with very low manufacturing tolerances, which led to precision machining and welding operations, together with numerous dimensional inspections and materials characterization tests to achieve the required quality standards

Ultrafast pump-probe reflectance spectroscopy: Why sodium makes Cu(In,Ga)Se2 solar cells better

KAUST Repository

Eid, Jessica; Usman, Anwar; Gereige, Issam; Duren, Jeroen Van; Lyssenko, Vadim; Leo, Karl; Mohammed, Omar F.

2015-01-01

Although Cu(In,Ga)Se2 (CIGS) solar cells have the highest efficiency of any thin-film solar cell, especially when sodium is incorporated, the fundamental device properties of ultrafast carrier transport and recombination in such cells remain not fully understood. Here, we explore the dynamics of charge carriers in CIGS absorber layers with varying concentrations of Na by femtosecond (fs) broadband pump-probe reflectance spectroscopy with 120 fs time resolution. By analyzing the time-resolved transient spectra in a different time domain, we show that a small amount of Na integrated by NaF deposition on top of sputtered Cu(In,Ga) prior to selenization forms CIGS, which induces slower recombination of the excited carriers. Here, we provide direct evidence for the elongation of carrier lifetimes by incorporating Na into CIGS.

Ultrafast pump-probe reflectance spectroscopy: Why sodium makes Cu(In,Ga)Se2 solar cells better

KAUST Repository

Eid, Jessica

2015-04-14

Although Cu(In,Ga)Se2 (CIGS) solar cells have the highest efficiency of any thin-film solar cell, especially when sodium is incorporated, the fundamental device properties of ultrafast carrier transport and recombination in such cells remain not fully understood. Here, we explore the dynamics of charge carriers in CIGS absorber layers with varying concentrations of Na by femtosecond (fs) broadband pump-probe reflectance spectroscopy with 120 fs time resolution. By analyzing the time-resolved transient spectra in a different time domain, we show that a small amount of Na integrated by NaF deposition on top of sputtered Cu(In,Ga) prior to selenization forms CIGS, which induces slower recombination of the excited carriers. Here, we provide direct evidence for the elongation of carrier lifetimes by incorporating Na into CIGS.

Exergetic optimization of a key design parameter in heat pump systems with economizer coupled with scroll compressor

International Nuclear Information System (INIS)

Ma, Guoyuan; Li, Xianguo

2007-01-01

The heat pump system with economizer coupled with scroll compressor can extend effectively its operating ranges and provide a technological method to enable the heat pump to run steadily and efficiently in severe weather conditions. The intermediate pressure, namely the working pressure of the refrigerant in the economizer, is an essential design parameter and affects crucially the performances of the heat pump system. According to the exergetic model setup for the heat pump system based on the second law of thermodynamics, the influences of the intermediate pressure on the performances are comprehensively analyzed using experimental data of the heat pump prototype. It is found that the optimal relative intermediate pressure (RIP) is between 1.1 and 1.3

Development of the immersed sodium flowmeter

International Nuclear Information System (INIS)

Chen Daolong

1994-09-01

An immersed sodium flowmeter of the range 3 m 3 /h is developed. It is a flowmeter of entire-sealed construction, it can be operated in sodium. Its construction, the theoretical calculation of the calibration characteristic and the pressure loss, the test facility and the calibration test are presented in detail. It analytical expression of the calibration characteristic in the temperature limit 200∼600 degree C and the error analysis are given. The basic error of this immersed sodium flowmeter is below +-2.3% of the measuring range. The immersed sodium flowmeter can be used to resolve the sodium flowrate measuring problems of the in-reactor component of LMFBR, for example, the flowrate measuring of the in-reactor sodium purification loop, the flowrate measuring of the immersed sodium pump and the flowrate measuring of the in-reactor test component

Improvements to the sodium supply system of a nuclear reactor core

International Nuclear Information System (INIS)

Chevallier, Rene; Marchais, Christian.

1981-01-01

This invention concerns an improvement to the sodium supply system of a nuclear reactor core and, in particular, concerns the area included between the outlet of the primary circulation pumps and the core proper. A simplified structure and a lightening of all this linking area between the circulation pumps and the distribution tank under the core is achieved and this results in a very significant reduction in the risks of deterioration and in a definite increase in the reliability of the reactor. The invention is therefore an improvement to the sodium supply system of the nuclear reactor core vessel with incorporated exchangers, in which the cool sodium, after passing through the primary exchangers, is collected in a ring compartment from whence it is taken up by the pumps and moved to at least one pipe reaching a distribution tank located under the reactor core [fr

Effects of chlorpromazine on Na+-K+-ATPase pumping and solute transport in rat hepatocytes

International Nuclear Information System (INIS)

Van Dyke, R.W.; Scharschmidt, B.F.

1987-01-01

Inhibition of Na+-K+-ATPase and sodium-dependent bile acid transport has been suggested as a mechanism for the cholestasis produced by certain drugs such as chlorpromazine. We examined the effects of chlorpromazine (and in selected studies, two of its metabolites) on Na+-K+-ATPase cation pumping (ouabain-suppressible 86 Rb uptake), exchangeable intracellular sodium content, membrane potential (assessed by 36 Cl- distribution), and sodium-dependent transport of taurocholate and alanine in primary cultures of rat hepatocytes. Chlorpromazine (10-300 microM), 7,8-dihydroxychlorpromazine (10-300 microM), and ouabain (0.1-2 mM), but not chlorpromazine sulfoxide, produced a concentration-dependent decrease in Na+-K+-ATPase cation pumping and an increase in intracellular sodium content. Chlorpromazine (100 microM) and ouabain (0.75 mM) also modestly decreased hepatocyte membrane potential. In further studies, chlorpromazine (75 and 100 microM) and ouabain (0.1, 0.5, and 0.75 mM) decreased initial sodium-dependent uptake rates of taurocholate and alanine by 18-63%. Although the steady-state intracellular content of alanine was decreased 25-53% by both agents, chlorpromazine increased the steady-state content of taurocholate by 171% and decreased taurocholate efflux, apparently related to partitioning of taurocholate into a large, slowly turning over intracellular pool. These studies provide direct evidence that chlorpromazine inhibits Na+-K+-ATPase cation pumping in intact cells and that partial inhibition of Na+-K+-ATPase cation pumping is associated with a reduction of both the electrochemical sodium gradient and sodium-dependent solute transport. These effects of chlorpromazine may contribute to chlorpromazine-induced cholestasis in animals and humans

Effects of chlorpromazine on Na+-K+-ATPase pumping and solute transport in rat hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Van Dyke, R.W.; Scharschmidt, B.F.

1987-11-01

Inhibition of Na+-K+-ATPase and sodium-dependent bile acid transport has been suggested as a mechanism for the cholestasis produced by certain drugs such as chlorpromazine. We examined the effects of chlorpromazine (and in selected studies, two of its metabolites) on Na+-K+-ATPase cation pumping (ouabain-suppressible /sup 86/Rb uptake), exchangeable intracellular sodium content, membrane potential (assessed by /sup 36/Cl- distribution), and sodium-dependent transport of taurocholate and alanine in primary cultures of rat hepatocytes. Chlorpromazine (10-300 microM), 7,8-dihydroxychlorpromazine (10-300 microM), and ouabain (0.1-2 mM), but not chlorpromazine sulfoxide, produced a concentration-dependent decrease in Na+-K+-ATPase cation pumping and an increase in intracellular sodium content. Chlorpromazine (100 microM) and ouabain (0.75 mM) also modestly decreased hepatocyte membrane potential. In further studies, chlorpromazine (75 and 100 microM) and ouabain (0.1, 0.5, and 0.75 mM) decreased initial sodium-dependent uptake rates of taurocholate and alanine by 18-63%. Although the steady-state intracellular content of alanine was decreased 25-53% by both agents, chlorpromazine increased the steady-state content of taurocholate by 171% and decreased taurocholate efflux, apparently related to partitioning of taurocholate into a large, slowly turning over intracellular pool. These studies provide direct evidence that chlorpromazine inhibits Na+-K+-ATPase cation pumping in intact cells and that partial inhibition of Na+-K+-ATPase cation pumping is associated with a reduction of both the electrochemical sodium gradient and sodium-dependent solute transport. These effects of chlorpromazine may contribute to chlorpromazine-induced cholestasis in animals and humans.

Insulin regulation of Na/K pump activity in rat hepatoma cells

International Nuclear Information System (INIS)

Gelehrter, T.D.; Shreve, P.D.; Dilworth, V.M.

1984-01-01

Insulin rapidly increases Na/K pump activity in HTC rat hepatoma cells in tissue culture, as measured by the ouabain-sensitive influx of the potassium analogue 86Rb+. Increased influx is observed within minutes and is maximal (70% above control) within 1-2 h. The effect appears to be mediated by the insulin receptors, as: the concentration dependence on insulin is identical to that for insulin induction of tyrosine aminotransferase and stimulation of 2-aminoisobutyric acid transport, proinsulin is 6% as potent as insulin, and the effect is blocked by anti-receptor antibodies. The early stimulation of potassium influx is not blocked by cycloheximide and is not associated with an increased number of pump sites as measured by 3 H-ouabain binding. The insulin effect is blocked by amiloride, which blocks sodium influx, and is mimicked by the sodium ionophore monensin, which increases sodium influx and intracellular accumulation. Insulin also rapidly increases the initial rate of 22 Na+ influx, suggesting that insulin may enhance Na/K pump activity, in part, by increasing intracellular sodium concentration. Incubation of HTC cells with insulin for 24 h causes complete unresponsiveness to the insulin induction of transaminase and stimulation of amino acid transport, a phenomenon mediated by postbinding mechanisms. In contrast, similar incubation with insulin does not cause unresponsiveness to the insulin stimulation of Na/K pump activity. Therefore, the site of regulation of responsiveness to insulin must be distal to, or separate from, those events causing stimulation of ion fluxes

A Takagi–Sugeno fuzzy power-distribution method for a prototypical advanced reactor considering pump degradation

Directory of Open Access Journals (Sweden)

Yue Yuan

2017-08-01

Full Text Available Advanced reactor designs often feature longer operating cycles between refueling and new concepts of operation beyond traditional baseload electricity production. Owing to this increased complexity, traditional proportional–integral control may not be sufficient across all potential operating regimes. The prototypical advanced reactor (PAR design features two independent reactor modules, each connected to a single dedicated steam generator that feeds a common balance of plant for electricity generation and process heat applications. In the current research, the PAR is expected to operate in a load-following manner to produce electricity to meet grid demand over a 24-hour period. Over the operational lifetime of the PAR system, primary and intermediate sodium pumps are expected to degrade in performance. The independent operation of the two reactor modules in the PAR may allow the system to continue operating under degraded pump performance by shifting the power production between reactor modules in order to meet overall load demands. This paper proposes a Takagi–Sugeno (T–S fuzzy logic-based power distribution system. Two T–S fuzzy power distribution controllers have been designed and tested. Simulation shows that the devised T–S fuzzy controllers provide improved performance over traditional controls during daily load-following operation under different levels of pump degradation.

A Takagi-Sugeno fuzzy power-distribution method for a prototypical advanced reactor considering pump degradation

Energy Technology Data Exchange (ETDEWEB)

Yuan, Yue [Institute of Nuclear and New Energy Technology, Tsinghua University, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Beijing (China); Coble, Jamie [Dept. of Nuclear Engineering, University of Tennessee, Knoxville (United States)

2017-08-15

Advanced reactor designs often feature longer operating cycles between refueling and new concepts of operation beyond traditional baseload electricity production. Owing to this increased complexity, traditional proportional–integral control may not be sufficient across all potential operating regimes. The prototypical advanced reactor (PAR) design features two independent reactor modules, each connected to a single dedicated steam generator that feeds a common balance of plant for electricity generation and process heat applications. In the current research, the PAR is expected to operate in a load-following manner to produce electricity to meet grid demand over a 24-hour period. Over the operational lifetime of the PAR system, primary and intermediate sodium pumps are expected to degrade in performance. The independent operation of the two reactor modules in the PAR may allow the system to continue operating under degraded pump performance by shifting the power production between reactor modules in order to meet overall load demands. This paper proposes a Takagi–Sugeno (T–S) fuzzy logic-based power distribution system. Two T–S fuzzy power distribution controllers have been designed and tested. Simulation shows that the devised T–S fuzzy controllers provide improved performance over traditional controls during daily load-following operation under different levels of pump degradation.

Experience on sodium removal from FBTR components in its operating phase

International Nuclear Information System (INIS)

Jambunathan, D.; Rao, M.S.; Krishnamachari, V.S.; Kasiviswanathan, K.V.; Rajan, M.

1997-01-01

FBTR is a 40 MWt/13 MWe loop type, sodium cooled mixed carbide fuelled reactor. There are two primary loops, two secondary loops and a common steam-water circuit. Criticality was achieved in 1985 and during the course of the 10 years of operation phase experience has been gained on the decontamination of certain core components, primary sodium pumps, CRDM parts, handling components and cold traps. This paper deals with the decontamination aspects of these components in detail. For core subassemblies a remote sodium cleaning system was provided in the hot cell. The unique feature of this system is that it pumps alcohol into wash chamber using compressed nitrogen. During cleaning, the sub assembly is loaded into the system using master slave manipulator and compressed nitrogen gas is used to pump alcohol into the system for cleaning the outer and inner surfaces of the sub assembly in cycles. Each cycle takes about 15 minutes and around 5 to 6 cycles of cleaning were employed to remove 100 g of sodium. The level of alcohol in the tank is measured by ultrasonic level probes. The used alcohol is pumped to medium active waste storage tank. Primary and secondary sodium pumps are the large components which were cleaned off sodium using steam and water in decontamination pit. Lower part of CRDM with a failed bellow was another component cleaned in decontamination pit. An electro decontamination technique was successfully developed to remove coloration on the lower part of CRDM for reuse. A stainless steel carrier with antimony capsule was the first radio active component to undergo sodium cleaning operation in decontamination pit meant for large primary sodium circuit components after making necessary modifications. Decontamination of other components such as fingers of grippers and scrapper rings of charging and discharging flasks was carried out with alcohol under inert atmosphere. The secondary loop cold trap was successfully cleaned by hydride decomposition and vacuum

Functional studies of sodium pump isoforms

DEFF Research Database (Denmark)

Clausen, Michael Jakob

The Na+,K+-ATPase is an essential ion pump found in all animal cells. It uses the energy from ATP hydrolysis to export three Na+ and import two K+, both against their chemical gradients and for Na+ also against the electrical potential. Mammals require four Na+,K+-ATPase isoforms that each have...... unique expression profiles and specialized functional features. We use a Two Electrode Voltage Clamp setup to determine pre-steady-state and steady-state characteristics of each isoform and design chimeras to pin-point the structural elements responsible for observed differences. With this strategy we...

Properties of an intermediate-duration inactivation process of the voltage-gated sodium conductance in rat hippocampal CA1 neurons.

Science.gov (United States)

French, Christopher R; Zeng, Zhen; Williams, David A; Hill-Yardin, Elisa L; O'Brien, Terence J

2016-02-01

Rapid transmembrane flow of sodium ions produces the depolarizing phase of action potentials (APs) in most excitable tissue through voltage-gated sodium channels (NaV). Macroscopic currents display rapid activation followed by fast inactivation (IF) within milliseconds. Slow inactivation (IS) has been subsequently observed in several preparations including neuronal tissues. IS serves important physiological functions, but the kinetic properties are incompletely characterized, especially the operative timescales. Here we present evidence for an "intermediate inactivation" (II) process in rat hippocampal CA1 neurons with time constants of the order of 100 ms. The half-inactivation potentials (V0.5) of steady-state inactivation curves were hyperpolarized by increasing conditioning pulse duration from 50 to 500 ms and could be described by a sum of Boltzmann relations. II state transitions were observed after opening as well as subthreshold potentials. Entry into II after opening was relatively insensitive to membrane potential, and recovery of II became more rapid at hyperpolarized potentials. Removal of fast inactivation with cytoplasmic papaine revealed time constants of INa decay corresponding to II and IS with long depolarizations. Dynamic clamp revealed attenuation of trains of APs over the 10(2)-ms timescale, suggesting a functional role of II in repetitive firing accommodation. These experimental findings could be reproduced with a five-state Markov model. It is likely that II affects important aspects of hippocampal neuron response and may provide a drug target for sodium channel modulation. Copyright © 2016 the American Physiological Society.

Electromagnetic pumping of liquid lithium in inertial confinement fusion reactors

International Nuclear Information System (INIS)

Baker, R.S.; Blink, J.A.; Tessier, M.J.

1983-01-01

The basic operating principles and geometries of ten electromagnetic pumps are described. Two candidate pumps, the annular-linear-induction pump and the helical-rotor electromagnetic pump, are compared for possible use in a full-scale liquid-lithium inertial confinement fusion reactor. A parametric design study completed for the helical-rotor pump is shown to be valid when applied to an experimental sodium pump. Based upon the preliminary HYLIFE requirements for a lithium flow rate per pump of 8.08 m 3 /s at a head of 82.5 kPa, a complete set of 70 variables are specified for a helical-rotor pump with either a normally conducting or a superconducting winding. The two alternative designs are expected to perform with efficiencies of 50 and 60%, respectively

The Analysis of an End Effect according to the Input Frequency Change in the EM Pump

International Nuclear Information System (INIS)

Kim, Hee Reyoung; Kim, Jong Man; Cha, Jae Eun; Choi, Jong Hyun; Nam, Ho Yoon

2006-01-01

In general, an electromagnetic (EM) pump is considered to circulate a liquid sodium coolant for a Sodium Fast Reactor (SFR). The EM pump has an end effect at both ends basically due to its finite core length. The generated magnetic field across the flow gap is distorted at both ends of the pump. Consequently, there arises reduction on the developed force by the vector product of that magnetic field and its perpendicular induced current. Especially, it experiences even the opposite pumping force near the pump inlet. That causes low efficiency of the pump and resultantly brings about bad performance of a pump. The present study theoretically shows that this end effect can be lessened by control of input frequency. It is predicted that pump operates much more efficiently in the range of low frequency around teen hertz than in that of high frequency over 60 Hz. The force density is investigated in the narrow annular channel of the pump with the length of 84cm according to pump axial coordinates at various frequency

Carbon in sodium - A status review of the U.S.A. R and D work

International Nuclear Information System (INIS)

McCown, J.J.; Bagnall, C.

1980-01-01

Liquid Metal Fast Breeder Reactors contain several types of steel in primary and secondary sodium systems. Austenitic stainless steels are used for in-core components, valves, heat exchangers, tanks and fuel cladding in primary systems. In power generating plants, the secondary or intermediate heat transport system may contain both austenitic and ferritic steel such as 2-1/4 Cr-l Mo type. Sodium circulating throughout the plant contains a number of impurities, metallic and non-metallic, with the steel interstitial elements carbon, hydrogen and oxygen being of prime importance. These elements can affect corrosion rates and mechanical behavior of materials. In the case of carbon, the sodium provides a transport medium with carburization and decarburization occurring in several parts of a system at rates depending upon temperature and types of steel. The US Sodium Technology R and D programs have investigated the behavior, transport, measurement and control of carbon in sodium. Measurement and control methods for carbon-containing materials which might contaminate the plant systems during reactor operation have also been studied. During the early 1970's, several US laboratories were active in studying carbon solubility, activity in sodium and interstitial transfer using both theoretical and experimental approaches. Modelling studies were done and models were used to predict FFTF and CRBRP materials requirements, component design and plant operating conditions. Over the past several years, carbon work has not been heavily emphasized. Most of the R and D studies have centered on improving chemical analysis methods for measuring active carbon, both by on-line monitors and by metal foil equilibration procedures; and on studies of pump oil-sodium reactions, reaction products, temperature effects and oil leak detection methods. One program at General Electric is investigating carburization-decarburization in a ferritic-austenitic system simulating conditions expected in

Carbon in sodium - A status review of the U.S.A. R and D work

Energy Technology Data Exchange (ETDEWEB)

McCown, J J; Bagnall, C [HEDL, Richland, WA (United States)

1980-05-01

Liquid Metal Fast Breeder Reactors contain several types of steel in primary and secondary sodium systems. Austenitic stainless steels are used for in-core components, valves, heat exchangers, tanks and fuel cladding in primary systems. In power generating plants, the secondary or intermediate heat transport system may contain both austenitic and ferritic steel such as 2-1/4 Cr-l Mo type. Sodium circulating throughout the plant contains a number of impurities, metallic and non-metallic, with the steel interstitial elements carbon, hydrogen and oxygen being of prime importance. These elements can affect corrosion rates and mechanical behavior of materials. In the case of carbon, the sodium provides a transport medium with carburization and decarburization occurring in several parts of a system at rates depending upon temperature and types of steel. The US Sodium Technology R and D programs have investigated the behavior, transport, measurement and control of carbon in sodium. Measurement and control methods for carbon-containing materials which might contaminate the plant systems during reactor operation have also been studied. During the early 1970's, several US laboratories were active in studying carbon solubility, activity in sodium and interstitial transfer using both theoretical and experimental approaches. Modelling studies were done and models were used to predict FFTF and CRBRP materials requirements, component design and plant operating conditions. Over the past several years, carbon work has not been heavily emphasized. Most of the R and D studies have centered on improving chemical analysis methods for measuring active carbon, both by on-line monitors and by metal foil equilibration procedures; and on studies of pump oil-sodium reactions, reaction products, temperature effects and oil leak detection methods. One program at General Electric is investigating carburization-decarburization in a ferritic-austenitic system simulating conditions expected in

Cooling Performance of ALIP according to the Air or Sodium Cooling Type

Energy Technology Data Exchange (ETDEWEB)

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

2015-05-15

ALIP pumps the liquid sodium by Lorentz force produced by the interaction of induced current in the liquid metal and their associated magnetic field. Even though the efficiency of the ALIP is very low compared to conventional mechanical pumps, it is very useful due to the absence of moving parts, low noise and vibration level, simplicity of flow rate regulation and maintenance, and high temperature operation capability. Problems in utilization of ALIP concern a countermeasure for elevation of internal temperature of the coil due to joule heating and how to increase magnetic flux density of Na channel gap. The conventional ALIP usually used cooling methods by circulating the air or water. On the other hand, GE-Toshiba developed a double stator pump adopting the sodium-immersed self-cooled type, and it recovered the heat loss in sodium. Therefore, the station load factor of the plant could be reduced. In this study, the cooling performance with cooling types of ALIP is analyzed. We developed thermal analysis models to evaluate the cooling performance of air or sodium cooling type of ALIP. The cooling performance is analyzed for operating parameters and evaluated with cooling type. 1-D and 3-D thermal analysis model for IHTS ALIP was developed, and the cooling performance was analyzed for air or sodium cooling type. The cooling performance for air cooling type was better than sodium cooling type at higher air velocity than 0.2 m/s. Also, the air temperature of below 270 .deg. demonstrated the better cooling performance as compared to sodium.

Relaxation of quadrupole orientation in an optically pumped alkali vapour

Energy Technology Data Exchange (ETDEWEB)

Bernabeu, E; Tornos, J

1985-04-01

The relaxation of quadrupole orientation (alignment) in an optically pumped alkali vapour is theoretically studied by taking into account the relaxation processes by alkali-buffer gas, alkali-alkali with spin exchange and alkali-cell wall (diffusion process) collisions. The relaxation transients of the quadrupole orientation are obtained by introducing a first-order weak-pumping approximation (intermediate pumping) less restrictive than the usually considered (zeroth order) one.

Insulin affects the sodium affinity of the rat adipocyte (Na+,K+)-ATPase

International Nuclear Information System (INIS)

Lytton, J.

1985-01-01

The K0.5 for intracellular sodium of the two forms of (Na + ,K + )-ATPase which exist in rat adipocytes has been determined by incubating the cells in the absence of potassium in buffers of varying sodium concentration; these conditions shut off the Na + pump and allow sodium to equilibrate into the cell. The activity of (Na + ,K + )-ATPase was then monitored with 86 Rb + /K + pumping which was initiated by adding isotope and KCl to 5 mM, followed by a 3-min uptake period. Atomic absorption and 22 Na + tracer equilibration were used to determine the actual intracellular [Na + ] under the different conditions. The K0.5 values thus obtained were 17 mM for alpha and 52 mM for alpha(+). Insulin treatment of rat adipocytes had no effect on the intracellular [Na+] nor on the Vmax of 86 Rb + /K + pumping, but did produce a shift in the sodium ion K0.5 values to 14 mM for alpha and 33 mM for alpha(+). This change in affinity can explain the selective stimulation of alpha(+) by insulin under normal incubation conditions

Sodium and Proton Effects on Inward Proton Transport through Na/K Pumps

Science.gov (United States)

Mitchell, Travis J.; Zugarramurdi, Camila; Olivera, J. Fernando; Gatto, Craig; Artigas, Pablo

2014-01-01

The Na/K pump hydrolyzes ATP to export three intracellular Na (Nai) as it imports two extracellular K (Ko) across animal plasma membranes. Within the protein, two ion-binding sites (sites I and II) can reciprocally bind Na or K, but a third site (site III) exclusively binds Na in a voltage-dependent fashion. In the absence of Nao and Ko, the pump passively imports protons, generating an inward current (IH). To elucidate the mechanisms of IH, we used voltage-clamp techniques to investigate the [H]o, [Na]o, and voltage dependence of IH in Na/K pumps from ventricular myocytes and in ouabain-resistant pumps expressed in Xenopus oocytes. Lowering pHo revealed that Ho both activates IH (in a voltage-dependent manner) and inhibits it (in a voltage-independent manner) by binding to different sites. Nao effects depend on pHo; at pHo where no Ho inhibition is observed, Nao inhibits IH at all concentrations, but when applied at pHo that inhibits pump-mediated current, low [Na]o activates IH and high [Na]o inhibits it. Our results demonstrate that IH is a property inherent to Na/K pumps, not linked to the oocyte expression environment, explains differences in the characteristics of IH previously reported in the literature, and supports a model in which 1), protons leak through site III; 2), binding of two Na or two protons to sites I and II inhibits proton transport; and 3), pumps with mixed Na/proton occupancy of sites I and II remain permeable to protons. PMID:24940773

Design and research on nuclear power plant EAS jet pump

International Nuclear Information System (INIS)

Chen Xingjiang; Fang Xiquan; Xie Jian; Yang Bin; Wang Xueling; Qi Yanli

2014-01-01

The jet pump is an important part of the PWR containment spray system. It will be performed the security functions under the accident conditions, which the containment spray system adds the right amount of sodium hydroxide through the jet pump to spray water. This paper describes the principle of jet pump. And the optimum structure dimensions were calculated according to the performance parameter and requirement of the jet pump. On the basis of foreign EAS jet pump design experience, the structure dimensions were modified according to the CFD analysis and performance test. Finally, the results of CFD analysis and performance test were provided. (authors)

Cw hyper-Raman laser and four-wave mixing in atomic sodium

Science.gov (United States)

Klug, M.; Kablukov, S. I.; Wellegehausen, B.

2005-01-01

Continuous wave hyper-Raman (HR) generation in a ring cavity on the 6s → 4p transition at 1640 nm in sodium is realized for the first time by two-photon excitation of atomic sodium on the 3s → 6s transition with a continuous wave (cw) dye laser at 590 nm and a single frequency argon ion laser at 514 nm. It is shown, that the direction and efficiency of HR lasing depends on the propagation direction of the pump waves and their frequencies. More than 30% HR gain is measured at 250 mW of pump laser powers for counter-propagating pump waves and a medium length of 90 mm. For much shorter interaction lengths and corresponding focussing of the pump waves a dramatic increase of the gain is predicted. For co-propagating pump waves, in addition, generation of 330 nm radiation on the 4p → 3s transition by a four-wave mixing (FWM) process is observed. Dependencies of HR and parametric four-wave generation have been investigated and will be discussed.

Design of DC Conduction Pump for PGSFR Active Decay Heat Removal System

Energy Technology Data Exchange (ETDEWEB)

Kim, Dehee; Hong, Jonggan; Lee, Taeho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

A DC conduction pump has been designed for the ADHRS of PGSFR. A VBA code developed by ANL was utilized to design and optimize the pump. The pump geometry dependent parameters were optimized to minimize the total current while meeting the design requirements. A double-C type dipole was employed to produce the calculated magnetic strength. Numerical simulations for the magnetic field strength and its distribution around the dipole and for the turbulent flow under magnetic force will be carried out. A Direct Current (DC) conduction Electromagnetic Pump (EMP) has been designed for Active Decay Heat Removal System (ADHRS) of PGSFR. The PGSFR has active as well as passive systems for the DHRS. The passive DHRS (PDHRS) works by natural circulation head and the ADHRS is driven by an EMP for the DHRS sodium loop and a blower for the finned-tube sodium-to-air heat exchanger (FHX). An Annular Linear Induction Pump (ALIP) can be also considered for the ADHRS, but DC conduction pump has been chosen. Selection basis of DHRS EMP is addressed and EMP design for single ADHRS loop with 1MWt heat removal capacity is introduced.

Radiative characteristics of CVL pumped dye laser

Energy Technology Data Exchange (ETDEWEB)

Kubo, Uichi; Ishiguro, Takahide

1987-09-01

This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or ethylene glycol was useful solvent for dye laser.

Structural assessment of intermediate printed circuit heat exchanger for sodium-cooled fast reactor with supercritical CO2 cycle

International Nuclear Information System (INIS)

Lee, Youho; Lee, Jeong Ik

2014-01-01

Highlights: • We numerically model PCHE stress arising from pressure, and thermal loadings. • Stress levels are the highest around S-CO 2 channels, due to high pressure of S-CO 2 . • The conventional analytic models for PCHE underestimate actual stress levels. • Plasticity sufficiently lowers stress levels at channel tips. • PCHE for SFR-SCO 2 is anticipated to assure compliance with ASME design standards. - Abstract: Structural integrity of intermediate Printed Circuit Heat Exchanger (PCHE) for Sodium-cooled Fast Reactor (SFR) attached to Supercritical CO 2 (S-CO 2 ) is investigated. ANSYS-Mechanical was used to simulate stress fields of representative PCHE channels, with temperature fields imported from FLUENT simulation. Mechanical stress induced by pressure loading is found to be the primary source of stress. As plasticity sufficiently lowers local stress concentration at PCHE channel tips, PCHE type intermediate heat exchangers made of SS316 are anticipated to reliably assure compliance with design standards prescribed in the ASME standards, thanks to the structure temperature that is below the effective creep inducing point. The actual life time of PCHE for SFR-SCO 2 is likely to be affected by mechanical behavior change of SS316 with reactions with S-CO 2 and fatigue

Deciphering excited state evolution in halorhodopsin with stimulated emission pumping.

Science.gov (United States)

Bismuth, Oshrat; Komm, Pavel; Friedman, Noga; Eliash, Tamar; Sheves, Mordechai; Ruhman, Sanford

2010-03-04

The primary photochemical dynamics of Hb. pharaonis Halorhodopsin (pHR) are investigated by femtosecond visible pump-near IR dump-hyperspectral probe spectroscopy. The efficiency of excited state depletion is deduced from transient changes in absorption, recorded with and without stimulated emission pumping (SEP), as a function of the dump delay. The concomitant reduction of photocycle population is assessed by probing the "K" intermediate difference spectrum. Results show that the cross section for stimulating emission is nearly constant throughout the fluorescent state lifetime. Probing "K" demonstrates that dumping produces a proportionate reduction in photocycle yields. We conclude that, despite its nonexponential internal conversion (IC) kinetics, the fluorescent state in pHR constitutes a single intermediate in the photocycle. This contrasts with conclusions drawn from the study of primary events in the related chloride pump from Hb. salinarum (sHR), believed to produce the "K" intermediate from a distinct short-lived subpopulation in the excited state. Our discoveries concerning internal conversion dynamics in pHR are discussed in light of recent expectations for similar excited state dynamics in both proteins.

Liquid metal flow control by DC electromagnetic pumps

International Nuclear Information System (INIS)

Borges, Eduardo Madeira; Braz Filho, Francisco Antonio; Guimaraes, Lamartine Nogueira Frutuoso

2006-01-01

The cooling system of high-density thermal power requires fluids of high thermal conductivity, such as liquid metals. Electromagnetic pumps can be used to liquid metal fluid flow control in cooling circuits. The operation of electromagnetic pumps used to flow control is based on Lorentz force. This force can be achieved by magnetic field and electric current interaction, controlled by external independent power supplies. This work presents the electromagnetic pump operational principles, the IEAv development scheme and the BEMC-1 simulation code. The theoretical results of BEMC-1 simulation are compared to electromagnetic pump operation experimental data, validating the BEMC-1 code. This code is used to evaluate the DC electromagnetic pump performance applied to Mercury flow control and others liquid metal such as Sodium, Lead and Bismuth, used in nuclear fast reactors. (author)

Regulation of the Na(+)-K+ pump activity and estimation of the reserve capacity in intact rat peritoneal mast cells

DEFF Research Database (Denmark)

Knudsen, Torben; Johansen, Torben

1990-01-01

Evidence is provided that regulation of the Na(+)-K+ pump activity in rat peritoneal mast cells occurs mainly through stimulation of the pump from inside the plasma membrane by sodium. It is demonstrated that there is a large reserve capacity for the exchange of intracellular sodium...... with extracellular potassium in these cells. The maximal pump activity was estimated to be 3230 pmol/10(6) cells per min and Km for extracellular potassium was 1.5 mM....

Crystal structure of the sodium-potassium pump (Na+,K+-ATPase) with bound potassium and ouabain

Science.gov (United States)

Ogawa, Haruo; Shinoda, Takehiro; Cornelius, Flemming; Toyoshima, Chikashi

2009-01-01

The sodium-potassium pump (Na+,K+-ATPase) is responsible for establishing Na+ and K+ concentration gradients across the plasma membrane and therefore plays an essential role in, for instance, generating action potentials. Cardiac glycosides, prescribed for congestive heart failure for more than 2 centuries, are efficient inhibitors of this ATPase. Here we describe a crystal structure of Na+,K+-ATPase with bound ouabain, a representative cardiac glycoside, at 2.8 Å resolution in a state analogous to E2·2K+·Pi. Ouabain is deeply inserted into the transmembrane domain with the lactone ring very close to the bound K+, in marked contrast to previous models. Due to antagonism between ouabain and K+, the structure represents a low-affinity ouabain-bound state. Yet, most of the mutagenesis data obtained with the high-affinity state are readily explained by the present crystal structure, indicating that the binding site for ouabain is essentially the same. According to a homology model for the high affinity state, it is a closure of the binding cavity that confers a high affinity. PMID:19666591

Crystal structure of the sodium-potassium pump (Na+,K+-ATPase) with bound potassium and ouabain.

Science.gov (United States)

Ogawa, Haruo; Shinoda, Takehiro; Cornelius, Flemming; Toyoshima, Chikashi

2009-08-18

The sodium-potassium pump (Na(+),K(+)-ATPase) is responsible for establishing Na(+) and K(+) concentration gradients across the plasma membrane and therefore plays an essential role in, for instance, generating action potentials. Cardiac glycosides, prescribed for congestive heart failure for more than 2 centuries, are efficient inhibitors of this ATPase. Here we describe a crystal structure of Na(+),K(+)-ATPase with bound ouabain, a representative cardiac glycoside, at 2.8 A resolution in a state analogous to E2.2K(+).Pi. Ouabain is deeply inserted into the transmembrane domain with the lactone ring very close to the bound K(+), in marked contrast to previous models. Due to antagonism between ouabain and K(+), the structure represents a low-affinity ouabain-bound state. Yet, most of the mutagenesis data obtained with the high-affinity state are readily explained by the present crystal structure, indicating that the binding site for ouabain is essentially the same. According to a homology model for the high affinity state, it is a closure of the binding cavity that confers a high affinity.

Ancient Systems of Sodium/Potassium Homeostasis as Predecessors of Membrane Bioenergetics.

Science.gov (United States)

Dibrova, D V; Galperin, M Y; Koonin, E V; Mulkidjanian, A Y

2015-05-01

Cell cytoplasm of archaea, bacteria, and eukaryotes contains substantially more potassium than sodium, and potassium cations are specifically required for many key cellular processes, including protein synthesis. This distinct ionic composition and requirements have been attributed to the emergence of the first cells in potassium-rich habitats. Different, albeit complementary, scenarios have been proposed for the primordial potassium-rich environments based on experimental data and theoretical considerations. Specifically, building on the observation that potassium prevails over sodium in the vapor of inland geothermal systems, we have argued that the first cells could emerge in the pools and puddles at the periphery of primordial anoxic geothermal fields, where the elementary composition of the condensed vapor would resemble the internal milieu of modern cells. Marine and freshwater environments generally contain more sodium than potassium. Therefore, to invade such environments, while maintaining excess of potassium over sodium in the cytoplasm, primordial cells needed means to extrude sodium ions. The foray into new, sodium-rich habitats was the likely driving force behind the evolution of diverse redox-, light-, chemically-, or osmotically-dependent sodium export pumps and the increase of membrane tightness. Here we present a scenario that details how the interplay between several, initially independent sodium pumps might have triggered the evolution of sodium-dependent membrane bioenergetics, followed by the separate emergence of the proton-dependent bioenergetics in archaea and bacteria. We also discuss the development of systems that utilize the sodium/potassium gradient across the cell membranes.

Large electro-magnetic pump design for application in the ASTRID sodium-cooled fast reactor

International Nuclear Information System (INIS)

Laffont, Guy; Rey, Frédéric; Aizawa, Rie; Suziki, Tetsu

2013-01-01

Conclusion: • Use of a LEMP motivated by several advantages in terms of the reactor design, operation and maintenance. • Collaboration agreement between the CEA and TOSHIBA Corporation came into force in April 2012 to carry out a joint work program on the ASTRID EMP design and development. • Preliminary LEMP calculations carried out by the CEA and TOSHIBA are in good agreement and provide a good confidence in the feasibility of the annular LEMP for the ASTRID intermediate sodium loop. • Theoretical and experimental investigations are currently underway at the CEA with the aim to improve the numerical tools. • In parallel, the ASTRID EMP conceptual design studies are ongoing at TOSHIBA (thermal and thermo-mechanical analyses to demonstrate the LEMP self-cooling, structural analysis of the casing, the supporting legs and the mechanical interfaces, definition of the power supply unit, instrumentation and remote control procedure). • This program is aiming at consolidating the ASTRID EMP conceptual design report and to support the design option choice for the ASTRID basic design

P-Q characteristic of the electromagnetic pump with the flow rate of 60 l/min

International Nuclear Information System (INIS)

Kim, Hee Reyoun; KIm, Jong Man; Cha, Jae Eun; Choi, Jong Hyun; Nam, Ho Yoon

2005-01-01

In general, an EM pump has been employed to circulate electrically conductive liquids like molten metals by Lorentz force generated from the magnetic field and its perpendicular current. Especially, at the Liquid Metal Reactor (LMR) which uses liquid sodium with high electrical conductivity as a coolant, an EM pump is noticed due to advantages over mechanical pump such as no rotating part, no noise and simplicity. In the present study, the EM pump of a pilot annular linear induction type with the flowrate of 60 l/min is designed by using electrical equivalent circuit method that is applied to linear induction machines. The designed pump is manufactured by consideration of the requirements of material and function in high temperature and sodium environments. Experimental characterization is carried out according to input currents and frequency. And compared analyses between theoretical prediction and experimental results are performed

Method of processing waste sodium

International Nuclear Information System (INIS)

Shimoyashiki, Shigehiro; Takahashi, Kazuo.

1982-01-01

Purpose: To enable safety store of waste sodium in the form of intermetallic compounds. Method: Waste sodium used in a reactor is mixed with molten metal under an inert gas atmosphere and resulted intermetallic compounds are stored in a closely sealed container to enable quasi-permanent safety store as inert compound. Used waste sodium particularly, waste sodium in the primary system containing radioactive substances is charged in a waste sodium melting tank having a heater on the side, the tank is evacuated by a vacuum pump and then sealed with gaseous argon supplied from a gaseous argon tank, and waste sodium is melted under heating. The temperature and the amount of the liquid are measured by a thermometer and a level meter respectively. While on the other hand, molten metal such as Sn, Pb and Zn having melting point above 300 0 C are charged in a metal melting tank and heated by a heater. The molten sodium and the molten metals are charged into a mixing tank and agitated to mix by an induction type agitator. Sodium vapors in the tank are collected by traps. The air in the tank is replaced with gaseous argon. The molten mixture is closely sealed in a drum can and cooled to solidify for safety storage. (Seki, T.)

Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 2, Book 1. Commercial plant conceptual design. Final report

Energy Technology Data Exchange (ETDEWEB)

1979-03-01

The conceptual design of the 100-MW solar tower focus commercial power plant is described in detail. Sodium is pumped up to the top of a tall tower where the receiver is located. The sodium is heated in the receiver and then flows down the tower, through a pressure reducing device, and thence into a large, hot storage tank which is located at ground level and whose size is made to meet a specific thermal energy storage capacity requirement. From this tank, the sodium is pumped by a separate pump, through a system of sodium-to-water steam generators. The steam generator system consists of a separate superheater and reheater operating in parallel and an evaporator unit operating in series with the other two units. The sodium flowing from the evaporator unit is piped to a cold storage tank. From the cold storage tank, sodium is then pumped up to the tip of the tower to complete the cycle. The steam generated in the steam generators is fed to a conventional off-the-shelf, high-efficiency turbine. The steam loop operates in a conventional rankine cycle with the steam generators serving the same purpose as a conventional boiler and water being fed to the evaporator with conventional feedwater pumps. The pressure reducing device (a standard drag valve, for example) serves to mitigate the pressure caused by the static head of sodium and thus allows the large tanks to operate at ambient pressure conditions. (WHK)

Radiative characteristics of CVL pumped dye laser

International Nuclear Information System (INIS)

Kubo, Uichi; Ishiguro, Takahide.

1987-01-01

This paper describes the radiative characteristics of CVL pumped dye laser. It is compared YAG-SH (530 nm) with CVL (511, 578 nm) and CVL (511 nm) for pumping source. Influence of solvent in dye laser power was examined. The present experimental results show that efficiency of CVL (511 nm) pumped dye laser was most high. When the dye solution is at a standstill, the efficiency of dye laser with water and Sodium Lauryl Sulfate (S.L.S., 2 %wt.) was most high among the four kinds of solvent. In the condition of dye solution flow, the water and S.L.S. or Ethylene Glycol was useful solvent for dye laser. (author)

Specificities of reactor coolant pumps units with lead and lead-bismuth coolant

International Nuclear Information System (INIS)

Beznosov, A.V.; Anotonenkov, M.A.; Bokov, P.A.; Baranova, V.S.; Kustov, M.S.

2009-01-01

The analysis results of impact of lead and lead-bismuth coolants specific properties on the coolants flow features in flow channels of the main and auxiliary circulating pumps are presented. Impossibility of cavitation initiation in flow channels of vane pumps pumping lead and lead-bismuth coolants was demonstrated. The experimental research results of discontinuity of heavy liquid metal coolant column were presented and conditions of gas cavitation initiation in coolant flow were discussed. Invalidity of traditional calculation methods of water and sodium coolants circulation pumps calculations for lead and lead-bismuth coolants circulation pumps was substantiated [ru

Sodium removal from CSRDM lower part by water vapour - CO2 process

International Nuclear Information System (INIS)

Sundar Raj, S.I.; Sreedhar, B.K.; Gurumoorthy, K.; Rajan, K.K.; Kalyanasundaram, P.; Rajan, M.; Vaidyanathan, G.

2006-01-01

Sodium is the primary and secondary coolant in fast reactors. Primary and secondary circuits components like Control and Safety Rod Drive Mechanism (CSRDM), pumps, heat exchangers etc. handle liquid sodium. Sodium has good affinity to oxygen and reacts vigorously with water. Hence sodium cleaning is the first and important activity in the maintenance of the components. In reactor components this cleaning process also helps in removing a major part of radioactive contaminants after which they are subjected to chemical decontamination. There are several methods available for removing sodium from components. Out of these, the water vapour-CO 2 process is selected for large components such as pumps, heat exchangers etc. while steam cleaning is used for the core sub assemblies. The cleaning processes are to be closely monitored to ensure safety because the release of hydrogen is to be kept below 4 % during the process. This paper discusses the in house facility and the experience in the successful use of the process in the cleaning of CSRDM. (author)

Assertion based verification methodology for HDL designs of primary sodium pump speed and eddy current flow measurement systems of PFBR

International Nuclear Information System (INIS)

Misra, M.K.; Menon, Saritha P.; Thirugnana Murthy, D.

2013-01-01

With the growing complexity and size of digital designs, functional verification has become a huge challenge. The validation and testing process accounts for a significant percentage of the overall development effort and cost for electronic systems. Many studies have shown that up to 70% of the design development time and resources are spent on functional verification. Functional errors manifest themselves very early in the design flow, and unless they are detected upfront, they can result in severe consequences - both financially and from a safety viewpoint. This paper covers the various types of verification methodologies and focuses on Assertion Based Verification Methodology for HDL designs, taking as case studies, the Primary Sodium Pump Speed and Eddy Current Flow Measurement Systems of PFBR. (author)

Some techniques for sodium removal in CIAE

International Nuclear Information System (INIS)

Yuan Waimai; Ding Dejun; Guo Huanfang; Hong Shuzhang; Zhou Shuxia; Shen Fenyang; Yang Zhongmin; Xu Yongxing

1997-01-01

In this paper the experiment and application on sodium removal and sodium disposal are presented. Steam-nitrogen process was used in CIAE for cleaning cold traps, sodium vapor traps, a sodium tank. Atomized water-nitrogen process was used for cleaning dummy fuel assembly for CEFR and a sintered stainless steel filter. Sprinkle process was used for cleaning some tubes. Bultylcellosolve was used for cleaning sintered stainless steel filter and sodium flow measurement device. Ethanol alcohol was used for cleaning electromagnetic pump. Paraffin, transformer-oil or their mixture was used for cleaning sodium valves, a sodium vapor trap and sodium-potassium alloy absorber. A small sintered stainless steel filter was distillated in vacuum. A simple sodium disposal device has been served for several years in CIA.E. It can dispose about 10 Kg sodium each time and the disposal process is no-aerosol. It operates in open air for non-radioactive sodium. In recent years a small sodium cleaning plant has been built. It can use atomized water, steam or organic alcohol to removal of sodium. The LAVEL cleaning plant and SLAPSO cleaning plant were introduced from Italy. And CEFR preliminary design on sodium cleaning for spent fuel assembly and on sodium removal-decontamination for large reactor components is introduced. Vapour-nitrogen process is planned to use in them. (author)

Design of the US-CRBRP sodium/water reaction pressure relief system

International Nuclear Information System (INIS)

Kruger, G.B.; Murdock, T.B.; Rodwell, E.; Sane, J.O.

1976-01-01

Protection against intermediate sodium system overpressure from the sodium/water reaction associated with large leaks within the CRBRP Steam Generators is provided by the sodium/water reaction pressure relief system (SWRPRS). This system consists of rupture disks connected to the intermediate sodium piping adjacent to the inlet to the superheater and outlet from the evaporator modules. The rupture discs relieve into piping that leads to reaction produce separator tanks, which in turn are vented to a centrifugal separator and flare stack arranged to burn hydrogen gas exhausting into the atmosphere. Analyses have been conducted using the TRANSWRAP Computer Code to predict the system pressures and flow rates during the large leak event. Experimental tests to be conducted in the large leak test rig (LLTR) will be used to confirm the analysis techniques used in the design

Solar-pumped lasers for space power transmission

Science.gov (United States)

Taussig, R.; Bruzzone, C.; Nelson, L.; Quimby, D.; Christiansen, W.

1979-01-01

Multi-Megawatt CW solar-pumped lasers appear to be technologically feasible for space power transmission in the 1990s time frame. A new concept for a solar-pumped laser is presented which utilizes an intermediate black body cavity to provide a uniform optical pumping environment for the lasant, either CO or CO2. Reradiation losses are minimized with resulting high efficiency operation. A 1 MW output laser may weigh as little as 8000 kg including solar collector, black body cavity, laser cavity and ducts, pumps, power systems and waste heat radiator. The efficiency of such a system will be on the order of 10 to 20%. Details of the new concept, laser design, comparison to competing solar-powered lasers and applications to a laser solar power satellite (SPS) concept are presented.

Corrosion performance of advanced structural materials in sodium.

Energy Technology Data Exchange (ETDEWEB)

Natesan, K.; Momozaki, Y.; Li, M.; Rink, D.L. (Nuclear Engineering Division)

2012-05-16

This report gives a description of the activities in design, fabrication, construction, and assembling of a pumped sodium loop for the sodium compatibility studies on advanced structural materials. The work is the Argonne National Laboratory (ANL) portion of the effort on the work project entitled, 'Sodium Compatibility of Advanced Fast Reactor Materials,' and is a part of Advanced Materials Development within the Reactor Campaign. The objective of this project is to develop information on sodium corrosion compatibility of advanced materials being considered for sodium reactor applications. This report gives the status of the sodium pumped loop at Argonne National Laboratory, the specimen details, and the technical approach to evaluate the sodium compatibility of advanced structural alloys. This report is a deliverable from ANL in FY2010 (M2GAN10SF050302) under the work package G-AN10SF0503 'Sodium Compatibility of Advanced Fast Reactor Materials.' Two reports were issued in 2009 (Natesan and Meimei Li 2009, Natesan et al. 2009) which examined the thermodynamic and kinetic factors involved in the purity of liquid sodium coolant for sodium reactor applications as well as the design specifications for the ANL pumped loop for testing advanced structural materials. Available information was presented on solubility of several metallic and nonmetallic elements along with a discussion of the possible mechanisms for the accumulation of impurities in sodium. That report concluded that the solubility of many metals in sodium is low (<1 part per million) in the temperature range of interest in sodium reactors and such trace amounts would not impact the mechanical integrity of structural materials and components. The earlier report also analyzed the solubility and transport mechanisms of nonmetallic elements such as oxygen, nitrogen, carbon, and hydrogen in laboratory sodium loops and in reactor systems such as Experimental Breeder Reactor-II, Fast Flux

Corrosion performance of advanced structural materials in sodium

International Nuclear Information System (INIS)

Natesan, K.; Momozaki, Y.; Li, M.; Rink, D.L.

2012-01-01

This report gives a description of the activities in design, fabrication, construction, and assembling of a pumped sodium loop for the sodium compatibility studies on advanced structural materials. The work is the Argonne National Laboratory (ANL) portion of the effort on the work project entitled, 'Sodium Compatibility of Advanced Fast Reactor Materials,' and is a part of Advanced Materials Development within the Reactor Campaign. The objective of this project is to develop information on sodium corrosion compatibility of advanced materials being considered for sodium reactor applications. This report gives the status of the sodium pumped loop at Argonne National Laboratory, the specimen details, and the technical approach to evaluate the sodium compatibility of advanced structural alloys. This report is a deliverable from ANL in FY2010 (M2GAN10SF050302) under the work package G-AN10SF0503 'Sodium Compatibility of Advanced Fast Reactor Materials.' Two reports were issued in 2009 (Natesan and Meimei Li 2009, Natesan et al. 2009) which examined the thermodynamic and kinetic factors involved in the purity of liquid sodium coolant for sodium reactor applications as well as the design specifications for the ANL pumped loop for testing advanced structural materials. Available information was presented on solubility of several metallic and nonmetallic elements along with a discussion of the possible mechanisms for the accumulation of impurities in sodium. That report concluded that the solubility of many metals in sodium is low (<1 part per million) in the temperature range of interest in sodium reactors and such trace amounts would not impact the mechanical integrity of structural materials and components. The earlier report also analyzed the solubility and transport mechanisms of nonmetallic elements such as oxygen, nitrogen, carbon, and hydrogen in laboratory sodium loops and in reactor systems such as Experimental Breeder Reactor-II, Fast Flux Test Facility, and

How Cells Can Control Their Size by Pumping Ions

Directory of Open Access Journals (Sweden)

Alan R. Kay

2017-05-01

Full Text Available The ability of all cells to set and regulate their size is a fundamental aspect of cellular physiology. It has been known for sometime but not widely so, that size stability in animal cells is dependent upon the operation of the sodium pump, through the so-called pump-leak mechanism (Tosteson and Hoffman, 1960. Impermeant molecules in cells establish an unstable osmotic condition, the Donnan effect, which is counteracted by the operation of the sodium pump, creating an asymmetry in the distribution of Na+ and K+ staving off water inundation. In this paper, which is in part a tutorial, I show how to model quantitatively the ion and water fluxes in a cell that determine the cell volume and membrane potential. The movement of water and ions is constrained by both osmotic and charge balance, and is driven by ion and voltage gradients and active ion transport. Transforming these constraints and forces into a set of coupled differential equations allows us to model how the ion distributions, volume and voltage change with time. I introduce an analytical solution to these equations that clarifies the influence of ion conductances, pump rates and water permeability in this multidimensional system. I show that the number of impermeant ions (x and their average charge have a powerful influence on the distribution of ions and voltage in a cell. Moreover, I demonstrate that in a cell where the operation of active ion transport eliminates an osmotic gradient, the size of the cell is directly proportional to x. In addition, I use graphics to reveal how the physico-chemical constraints and chemical forces interact with one another in apportioning ions inside the cell. The form of model used here is applicable to all membrane systems, including mitochondria and bacteria, and I show how pumps other than the sodium pump can be used to stabilize cells. Cell biologists may think of electrophysiology as the exclusive domain of neuroscience, however the electrical

Downstream shift in sodium pump activity along the nephron during acute hypertension

DEFF Research Database (Denmark)

Magyar, C E; Zhang, Y; Holstein-Rathlou, N H

2001-01-01

Acute hypertension rapidly inhibits proximal tubule (PT) Na,K-ATPase activity and sodium reabsorption 30 to 40%, increasing sodium and volume delivery to the thick ascending loop of Henle (TALH) and macula densa, providing the error signal for tubuloglomerular feedback. The hypothesis was tested...... in rats that an acute increase in sodium and volume delivery to the TALH would acutely increase outer medulla Na,K-ATPase activity. Flow to the TALH was increased by either (1) elevating BP (102 to 160 mmHg) for 5 min by constricting arteries (hypertension) or (2) inhibiting PT sodium and volume...... reabsorption with the carbonic anhydrase inhibitor benzolamide: 2 mg/kg in 300 mM NaHCO(3) at 50 microl/min for 5 to 7 min. Both stimuli increased urine output and lithium clearance three- to four-fold and increased basolateral Na,K-ATPase activity about 40%. In homogenates, acute hypertension increased...

Benefits and applications of modular hydroelectric pumped storage

International Nuclear Information System (INIS)

Koebbe, R.S.

1991-01-01

This paper reports on hydroelectric pumped storage which is the only proven and most efficient technology available for energy storage. It is used by utilities to provide peak and intermediate power and to optimize overall system performance. Because of increased environmental and regulatory constraints, few acceptable sites, long schedules, and huge financial commitments, large conventional pumped storage plants, are now virtually impossible to build. As an alternative, small modular pumped storage, with project sizes ranging from 25 MW to 200 MW, was created to overcome the difficulties of conventional projects. The modular approach involves standardizing the elements of a pumped storage plant by utilizing specialized siting techniques and optimizing design, equipment, and construction. Compared with conventional pumped storage, the modular design can reduce cost and expedite schedule; reduce environmental concerns and permitting obstacles; and expand applications of energy storage on a utility's system

Cyclophilin B interacts with sodium-potassium ATPase and is required for pump activity in proximal tubule cells of the kidney.

Science.gov (United States)

Suñé, Guillermo; Sarró, Eduard; Puigmulé, Marta; López-Hellín, Joan; Zufferey, Madeleine; Pertel, Thomas; Luban, Jeremy; Meseguer, Anna

2010-11-10

Cyclophilins (Cyps), the intracellular receptors for Cyclosporine A (CsA), are responsible for peptidyl-prolyl cis-trans isomerisation and for chaperoning several membrane proteins. Those functions are inhibited upon CsA binding. Albeit its great benefits as immunosuppressant, the use of CsA has been limited by undesirable nephrotoxic effects, including sodium retention, hypertension, hyperkalemia, interstial fibrosis and progressive renal failure in transplant recipients. In this report, we focused on the identification of novel CypB-interacting proteins to understand the role of CypB in kidney function and, in turn, to gain further insight into the molecular mechanisms of CsA-induced toxicity. By means of yeast two-hybrid screens with human kidney cDNA, we discovered a novel interaction between CypB and the membrane Na/K-ATPase β1 subunit protein (Na/K-β1) that was confirmed by pull-down, co-immunoprecipitation and confocal microscopy, in proximal tubule-derived HK-2 cells. The Na/K-ATPase pump, a key plasma membrane transporter, is responsible for maintenance of electrical Na+ and K+ gradients across the membrane. We showed that CypB silencing produced similar effects on Na/K-ATPase activity than CsA treatment in HK-2 cells. It was also observed an enrichment of both alpha and beta subunits in the ER, what suggested a possible failure on the maturation and routing of the pump from this compartment towards the plasma membrane. These data indicate that CypB through its interaction with Na/K-β1 might regulate maturation and trafficking of the pump through the secretory pathway, offering new insights into the relationship between cyclophilins and the nephrotoxic effects of CsA.

Feasibility study on the type of KALIMER coolant circulation pump

International Nuclear Information System (INIS)

Nam, H. Y.; Kim, Y. K.; Lee, Y. B.; Hwang, J. S.; Choi, S. K.

1997-07-01

The characteristics of mechanical pump and electromagnetic (EM) pump for liquid sodium coolant in a liquid metal reactor are compared and analysed as a design concept of KALIMER coolant pumps. The type of coolant circulation pump affects the selection of reactor type, economics, and reliability of reactor. Though the mechanical pump has much application experience and give satisfaction to the reliability of developed reactor type, the possibility of development is limited and its large weight and volume have a negative effect on the design of the economical liquid metal reactor. The large scale electromagnetic pump has not been verified yet, but it is expected to be demonstrated in time. Because the size of EM pump is small relative to the mechanical pump, the compact reactor design is possible. Therefore the selection of EM pump can be one of the methods to improve the economics. Since the shape of EM pump can be varied according to the arrangement of electromagnet coils, a new or unique reactor type can be developed easily in the process of KALIMER development. In the view point of economic LMR development, it is desirable to adopt the electromagnetic pump. (author). 50 refs., 11 tabs., 24 figs

Connection of indicator of sodium burning in enclosed area

Energy Technology Data Exchange (ETDEWEB)

Enenkl, V

1975-01-15

The connection is described of an indicator of sodium burning in a closed area. The air and combustion product mixture is sucked by a pump through a pipe from the steam generator. Following possible aftercooling it is passed to a hermetically sealed vessel with distilled water. Fitted in the vessel are electrodes wired to a galvanometer. The air-sodium combustion product mixture is directed to the bottom of the vessel and bubbles through the distilled water. Sodium oxide contained in the mixture dissolves in the water and forms an electrolytic solution. The voltage produced at the electrodes may be indicated by the galvanometer.

Design study of an IHX support structure for a POOL-TYPE Sodium-cooled fast reactor

International Nuclear Information System (INIS)

Park, Chang Gyu; Kim, Jong Bum; Lee, Jae Han

2009-01-01

The IHX (Intermediate Heat eXchanger) for a pool-type SFR (Sodium-cooled Fast Reactor) system transfers heat from the primary high temperature sodium to the intermediate cold temperature sodium. The upper structure of the IHX is a coaxial structure designed to form a flow path for both the secondary high temperature and low temperature sodium. The coaxial structure of the IHX consists of a central downcomer and riser for the incoming and outgoing intermediate sodium, respectively. The IHX of a pool-type SFR is supported at the upper surface of the reactor head with an IHX support structure that connects the IHX riser cylinder to the reactor head. The reactor head is generally maintained at the low temperature regime, but the riser cylinder is exposed in the elevated temperature region. The resultant complicated temperature distribution of the co-axial structure including the IHX support structure may induce a severe thermal stress distribution. In this study, the structural feasibility of the current upper support structure concept is investigated through a preliminary stress analysis and an alternative design concept to accommodate the IHTS (Intermediate Heat Transport System) piping expansion loads and severe thermal stress is proposed. Through the structural analysis it is found that the alternative design concept is effective in reducing the thermal stress and acquiring structural integrity

Single-phase pump model for analysis of LMFBR heat transport systems

International Nuclear Information System (INIS)

Madni, I.K.; Cazzoli, E.

1978-05-01

A single-phase pump model for transient and steady-state analysis of LMFBR heat transport systems is presented. Fundamental equations of the model are angular momentum balance to determine transient impeller speed and mass balance (including thermal expansion effects) to determine the level of sodium in the pump tank. Pump characteristics are modeled by homologous head and torque relations. All regions of pump operation are represented with reverse rotation allowed. The model also includes option for enthalpy rise calculations and pony motor operation. During steady state, the pump operating speed is determined by matching required head with total load in the circuit. Calculated transient results are presented for pump coastdown and double-ended pipe break accidents. The report examines the influence of frictional torque and specific speed on predicted response for the pump coastdown to natural circulation transient. The results for a double-ended pipe break accident indicate the necessity of including all regions of operation for pump characteristics

Performance of a hybrid chemical/mechanical heat pump

Science.gov (United States)

Silvestri, John J.; Scaringe, Robert P.; Grzyll, Lawrence R.

1990-01-01

The authors present the design and preliminary results of the performance of a hybrid chemical/mechanical, low-lift (20 C) heat pump. Studies have indicated that this heat pump has several advantages over the traditional single fluid vapor compression (reverse Rankine) heat pump. Included in these benefits are: 1) increased COPc due to the approximation of the cycle to the Lorenz cycle and due to the availability of the heat of solution, along with the heat of vaporization, to provide cooling; and 2) ease of variation in system cooling capacity by changing the fluid composition. The system performance is predicted for a variety of refrigerant-absorbent pairs. Cooling capacity is determined for systems operating with ammonia as the refrigerant and lithium nitrate and sodium thiocyanate as the absorbents and also with water as the refrigerant and magnesium chloride, potassium hydroxide, lithium bromide, sodium hydroxide, and sulfuric acid as the absorbents. Early indications have shown that the systems operating with water as the refrigerant operate at 2-4 times the capacity of the ammonia-refrigerant-based systems. Using existing working fluids in the proposed innovative design, a coefficient-of-performance improvement of 21 percent is possible when compared to the best vapor compression systems analyzed.

Development Status on Innovative Sodium-Cooled Fast Reactor (JSFR)

International Nuclear Information System (INIS)

Yanagisawa, Tsutomu; Sato, Kazujiro

2006-01-01

The first step in Japan's nuclear fuel cycle policy is to introduce MOX recycle in light water reactors (LWRs) and the final step is to establish multiple TRU recycle in fast reactors (FRs), with the goal of realizing a stable supply, effective use of nuclear fuel resources, and the environmentally friendly production of energy. Therefore, a feasibility study on commercialized FR cycle systems has been launched since July 1999 by a Japanese joint project team of Japan Atomic Energy Agency (JAEA) and the Japan Atomic Power Company (JAPC: the representative of the electric utilities) in cooperation with Central Research Institute of Electric Power Industry (CRIEPI) and vendors. In the period from July 1999 to March 2001, the feasibility study phase-I was conducted to screen out representative FR cycle concepts. In the feasibility study phase-II (April 2001 - March 2006), investigations in to the representative FR concepts were carried out to clarify the most promising concept for commercial deployment. This paper describes an innovative sodium-cooled FR, which is named as the JAEA Sodium-cooled FR (JSFR), as the most promising FR concept that meets the Generation-IV performance target. The JSFR employs several advanced technologies, such as an oxide dispersion strengthened (ODS) cladding for higher burn-up, a short-piping configuration with less elbows by adopting high chromium steel, a large scale integrated intermediate heat exchanger with a primary circulation pump, etc. Based on the design, construction and operation experiences of JOYO and MONJU, there are extensive technology bases for sodium-cooled FRs. Nevertheless, several innovative technologies implemented into the JSFR have to be developed in order to realize higher economic competitiveness by reducing construction costs and improving plant availability

Design of a Mechanical NaK Pump for Fission Space Power

Science.gov (United States)

Mireles, Omar R.; Bradley, David E.; Godfroy, Thomas

2011-01-01

Alkali liquid metal cooled fission reactor concepts are under development for spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid, which has specific pumping requirements. Traditionally, electromagnetic linear induction pumps have been used to provide the required flow and pressure head conditions for NaK systems but they can be limited in performance, efficiency, and number of available vendors. The objective of the project was to develop a mechanical NaK centrifugal pump that takes advantages of technology advances not available in previous liquid metal mechanical pump designs. This paper details the design, build, and performance test of a mechanical NaK pump developed at NASA Marshall Space Flight Center. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

Flame photometric detection of sodium leaks: Tests on a fullscale model for the control gear sodium rig

International Nuclear Information System (INIS)

Grundy, B.R.; Knowles, P.

1971-01-01

The proposed arrangement for detecting sodium leaks from the large flanges of the Control Gear Sodium Rig (Test Section No. 8, MCTR) at REML is to jacket then in a secondary containment from which air samples will be continuously pumped. Pipework feeds the air to a flame photometer which responds if soditun is present. To prove that sodium smoke could be transferred through the system, tests were performed on a fullscale model by burning small amounts of sodium in different jackets. Large signals free from fluctuations were obtained in all tests, peak response occurring in 2 1/4 minutes or less. The signal quickly cleared after isolating the appropriate vessel. A waiting period of several hours was sufficient to reduce the signal to zero, no cleaning of pipework, etc being necessary. In contrast, samples of two lagging materials heated to 400 °C gave no response with the photometer at maximum sensitivity. (author)

Site specific health and safety plan, 100-HR-3 pump and treat. Revision 2

International Nuclear Information System (INIS)

St John, C.H.

1997-09-01

The 100-HR-3 Pump and Treat system is a groundwater remedial action to remove Hexavalent Chromium (Cr+6) from the groundwater underlying the 100-HR-3 Operable Unit. This plan covers operation, maintenance, repairs, resin exchange and equipment removal/installation. The 100-HR-3 Operable Unit addresses groundwater underlying the 100-D Area. The primary groundwater contaminant is Chromium +6. The chromium contamination resulted from the use of sodium dichromate during past reactor operations. Sodium dichromate was used to treat reactor coolant water during reactor operations. The purpose of this Pump and Treat system is to pump contaminated groundwater through above ground ion exchange resin and then return treated water to aquifer. Chromium levels extracted from the wells are anticipated to range in the low parts per billion (∼50 ppb) which is the drinking water limit for Cr+6

Sodium--NaK engineering handbook. Volume IV. Sodium pumps, valves, piping, and auxiliary equipment

International Nuclear Information System (INIS)

Foust, O.J.

1978-01-01

The handbook is useful for designers in the Liquid Metals Fast Breeder Reactor (LMFBR) program and by the engineering and scientific community performing investigation and experimentation requiring high-temperature Na and NaK technology. Data are presented for pumps, bearings and seals, valves, vessels and piping, and auxiliary equipment including vapor traps, freeze plugs, fuel-channel flow regulators, antivortexing devices, and miscellaneous mechanical elements. Reactor materials are also discussed

Heat pumps in western Switzerland

International Nuclear Information System (INIS)

Freymond, A.

2003-01-01

The past ten years have seen an extraordinary expansion of heat-pump market figures in the western (French speaking) part of Switzerland. Today, more than 14,000 units are in operation. This corresponds to about 18% of all the machines installed in the whole country, compared to only 10 to 12% ten years ago. This success illustrates the considerable know-how accumulated by the leading trade and industry during these years. It is also due to the promotional program 'Energy 2000' of the Swiss Federal Department of Energy that included the heat pump as a renewable energy source. Already in 1986, the Swiss Federal Institute of Technology in Lausanne was equipped with a huge heat pump system comprising two electrically driven heat pumps of 3.5 MW thermal power each. The heat source is water drawn from the lake of Geneva at a depth of 70 meters. An annual coefficient of performance of 4.5 has been obtained since the commissioning of the plant. However, most heat pump installations are located in single-family dwellings. The preferred heat source is geothermal heat, using borehole heat exchangers and an intermediate heat transfer fluid. The average coefficient of performance of these installations has been increased from 2.5 in 1995 to 3.1 in 2002

Cyclophilin B interacts with sodium-potassium ATPase and is required for pump activity in proximal tubule cells of the kidney.

Directory of Open Access Journals (Sweden)

Guillermo Suñé

Full Text Available Cyclophilins (Cyps, the intracellular receptors for Cyclosporine A (CsA, are responsible for peptidyl-prolyl cis-trans isomerisation and for chaperoning several membrane proteins. Those functions are inhibited upon CsA binding. Albeit its great benefits as immunosuppressant, the use of CsA has been limited by undesirable nephrotoxic effects, including sodium retention, hypertension, hyperkalemia, interstial fibrosis and progressive renal failure in transplant recipients. In this report, we focused on the identification of novel CypB-interacting proteins to understand the role of CypB in kidney function and, in turn, to gain further insight into the molecular mechanisms of CsA-induced toxicity. By means of yeast two-hybrid screens with human kidney cDNA, we discovered a novel interaction between CypB and the membrane Na/K-ATPase β1 subunit protein (Na/K-β1 that was confirmed by pull-down, co-immunoprecipitation and confocal microscopy, in proximal tubule-derived HK-2 cells. The Na/K-ATPase pump, a key plasma membrane transporter, is responsible for maintenance of electrical Na+ and K+ gradients across the membrane. We showed that CypB silencing produced similar effects on Na/K-ATPase activity than CsA treatment in HK-2 cells. It was also observed an enrichment of both alpha and beta subunits in the ER, what suggested a possible failure on the maturation and routing of the pump from this compartment towards the plasma membrane. These data indicate that CypB through its interaction with Na/K-β1 might regulate maturation and trafficking of the pump through the secretory pathway, offering new insights into the relationship between cyclophilins and the nephrotoxic effects of CsA.

On the Safety and Performance Demonstration Tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and Validation and Verification of Computational Codes

Directory of Open Access Journals (Sweden)

Jong-Bum Kim

2016-10-01

Full Text Available The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR has been developed and the validation and verification (V&V activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1, produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

On the safety and performance demonstration tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and validation and verification of computational codes

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Bum; Jeong, Ji Young; Lee, Tae Ho; Kim, Sung Kyun; Euh, Dong Jin; Joo, Hyung Kook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V and V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V and V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

On the safety and performance demonstration tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and validation and verification of computational codes

International Nuclear Information System (INIS)

Kim, Jong Bum; Jeong, Ji Young; Lee, Tae Ho; Kim, Sung Kyun; Euh, Dong Jin; Joo, Hyung Kook

2016-01-01

The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V and V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V and V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results

Thermal performance tests on a sodium-to-sodium heat exchanger

International Nuclear Information System (INIS)

Prahlad, B.; Kale, R.D.; Rajan, K.K.

1990-01-01

Thermal performance of a 3 MW sodium-to-sodium intermediate heat exchanger (IHX) was evaluated under temperature conditions typical of a Fast Breeder Reactor IHX. A regenerative figure of eight loop was used with the heat exchanger at the cross over point, and a 500 kW heat source and an air cooled sink to maintain the desired test conditions. The overall heat transfer coefficient was found to vary from 4.02 to 4.87 kW/m 2 ·K for Peclet numbers varying from 37 to 112.5 on the shell side and 44.4 to 133.5 on the tube side respectively. The Peclet numbers were representative of low turbulent regime in this case. While the overall heat transfer coefficient was found close to predictions using Lubarsky's correlation, it was somewhat lower than that predicted by later correlations of Spukunsky and Borishansky. The reasons for the lower overall heat transfer coefficient have been explained in terms of possible maldistribution of shell side flow in low turbulent regime reducing the effective heat transfer area and increased thermal contact resistance. Based on their findings the authors feel that heat transfer in a sodium-to-sodium heat exchanger at low Peclet numbers is expected to differ from that obtained with large Peclet numbers. (author)

Bipolar and Related Disorders Induced by Sodium 4-Phenylbutyrate in a Male Adolescent with Bile Salt Export Pump Deficiency Disease.

Science.gov (United States)

Vitale, Giovanni; Simonetti, Giulia; Pirillo, Martina; Taruschio, Gianfranco; Andreone, Pietro

2016-09-01

Bile Salt Export Pump (BSEP) Deficiency disease, including Progressive Familial Intrahepatic Cholestasis type 2 (PFIC2), is a rare disease, usually leading within the first ten years to portal hypertension, liver failure, hepatocellular carcinoma. Often liver transplantation is needed. Sodium 4-phenylbutyrate (4-PB) seems to be a potential therapeutic compound for PFIC2. Psychiatric side effects in the adolescent population are little known and little studied since the drug used to treat children and infants. So we described a case of Caucasian boy, suffering from a late onset PFIC2, listed for a liver transplant when he was sixteen and treated with 4-FB (200 mg per kilogram of body weight per day). The drug was discontinued for the onset of bipolar and related disorders. This case illustrates possible psychiatric side effects of the drug.

Scrape-off profiles and effects of limiter pumping in Tore Supra

International Nuclear Information System (INIS)

Budny, R.

1986-11-01

A one dimensional plasma scrape-off model was used to simulate Tore Supra discharges which are limited by various combinations of the pumped and inner limiters. Scrape-off profiles of the electron density and temperature, ion temperature, and neutral density are given. For each case, various fractions of the ion flux to the neutralizers were assumed to be pumped. Modifications of the scrap-off profiles caused by pumping are predicted. Pumping efficiencies are calculated including the effects of flux amplification caused by recycling. The pumping efficiency is estimated to be 8% for low-power discharges formed on the outer pumped limiter, 7.5% for intermediate-power discharges formed on the seven-module pumped-limiter system, and 5% for full-power discharges formed on both the inner limiter and the pumped-limiter system. The maximum particle removal rate is estimated to be 150 Tl/s

Sodium-based hydrides for thermal energy applications

Science.gov (United States)

Sheppard, D. A.; Humphries, T. D.; Buckley, C. E.

2016-04-01

Concentrating solar-thermal power (CSP) with thermal energy storage (TES) represents an attractive alternative to conventional fossil fuels for base-load power generation. Sodium alanate (NaAlH4) is a well-known sodium-based complex metal hydride but, more recently, high-temperature sodium-based complex metal hydrides have been considered for TES. This review considers the current state of the art for NaH, NaMgH3- x F x , Na-based transition metal hydrides, NaBH4 and Na3AlH6 for TES and heat pumping applications. These metal hydrides have a number of advantages over other classes of heat storage materials such as high thermal energy storage capacity, low volume, relatively low cost and a wide range of operating temperatures (100 °C to more than 650 °C). Potential safety issues associated with the use of high-temperature sodium-based hydrides are also addressed.

Conceptual Design of Liquid Sodium Charging and Draining System of STELLA-2

Energy Technology Data Exchange (ETDEWEB)

Cho, Chungho; Nam, Ho-Yun; Kim, Jong-Man; Ko, Yung Joo; Kim, Byeongyeon; Cho, Youngil; Eoh, Jeahyuk; Yoon, Jung; Kim, Hyungmo; Lee, Hyeong-Yeon; Lee, Yong Bum; Jeong, Ji-Young; Kim, Jong-Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

STELLA program consist of two phases. In the first phase of the program, separated effects tests for demonstrating the thermal-hydraulic performances of major components such as a decay heat exchanger (DHX), Natural-draft sodium-to-air heat exchanger (AHX) of the decay heat removal system, and mechanical sodium pump of the primary heat transport system (PHTS) had been successfully performed using STELLA-1 in 2015. Now is the time for us to proceed to the second phase of STELLA program. In the second phase, to demonstrate thermal-hydraulic performances and safety features and to produce base data for the specific design approval for the PGSFR (Prototype Generation IV Sodium-cooled Fast Reactor) which will be constructed by 2028 in Korea, integral effects tests will be carried out using the STELLA-2 test facility which is underway with detailed design and will be constructed in 2018. To establish the maintenance easiness of test facility and to prevent a de-functionalization of elementary sodium component located under the main experimental sodium loops, arrangement area was separated the sodium charging and draining piping area from main system experimental piping area. The operation margin of test facility and the best use of electro-magnetic pumps were established according to employ connecting line between RV charging piping and main experimental system charging piping. To prevent liquid sodium inflow into the piping of gas supply system, the overflow line was employed in sodium expansion tanks of PHDRS and ADHRS, RV, and reservoirs of IHTS.

Conceptual Design of Liquid Sodium Charging and Draining System of STELLA-2

International Nuclear Information System (INIS)

Cho, Chungho; Nam, Ho-Yun; Kim, Jong-Man; Ko, Yung Joo; Kim, Byeongyeon; Cho, Youngil; Eoh, Jeahyuk; Yoon, Jung; Kim, Hyungmo; Lee, Hyeong-Yeon; Lee, Yong Bum; Jeong, Ji-Young; Kim, Jong-Bum

2016-01-01

STELLA program consist of two phases. In the first phase of the program, separated effects tests for demonstrating the thermal-hydraulic performances of major components such as a decay heat exchanger (DHX), Natural-draft sodium-to-air heat exchanger (AHX) of the decay heat removal system, and mechanical sodium pump of the primary heat transport system (PHTS) had been successfully performed using STELLA-1 in 2015. Now is the time for us to proceed to the second phase of STELLA program. In the second phase, to demonstrate thermal-hydraulic performances and safety features and to produce base data for the specific design approval for the PGSFR (Prototype Generation IV Sodium-cooled Fast Reactor) which will be constructed by 2028 in Korea, integral effects tests will be carried out using the STELLA-2 test facility which is underway with detailed design and will be constructed in 2018. To establish the maintenance easiness of test facility and to prevent a de-functionalization of elementary sodium component located under the main experimental sodium loops, arrangement area was separated the sodium charging and draining piping area from main system experimental piping area. The operation margin of test facility and the best use of electro-magnetic pumps were established according to employ connecting line between RV charging piping and main experimental system charging piping. To prevent liquid sodium inflow into the piping of gas supply system, the overflow line was employed in sodium expansion tanks of PHDRS and ADHRS, RV, and reservoirs of IHTS

Design of a Mechanical NaK Pump for Fission Space Power Systems

Science.gov (United States)

Mireles, Omar R.; Bradley, David; Godfroy, Thomas

2010-01-01

Alkali liquid metal cooled fission reactor concepts are under development for mid-range spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid. Traditionally, linear induction pumps have been used to provide the required flow and head conditions for liquid metal systems but can be limited in performance. This paper details the design, build, and check-out test of a mechanical NaK pump. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

Effects of pancreatic digestive enzymes, sodium bicarbonate, and a proton pump inhibitor on steatorrhoea caused by pancreatic diseases.

Science.gov (United States)

Nakamura, T; Takebe, K; Kudoh, K; Ishii, M; Imamura, K; Kikuchi, H; Kasai, F; Tandoh, Y; Yamada, N; Arai, Y

1995-01-01

Forty-five patients with pancreatic steatorrhoea (27 with calcified pancreatitis, 13 with non-calcified pancreatitis, two with pancreaticoduodenectomy, one with total pancreatectomy, and two with pancreatic cancer) were divided into four groups and given the following medication for 2 to 4 weeks: 4 to 6 g/day of sodium bicarbonate (group I); 9 g/day of high-lipase pancreatin (lipase, 56,600 U/g, Fédération Internationale Pharmaceutique (FIP); group II); 12 to 24 tablets or 9.0 g of commercial pancreatic enzyme preparations (group III); or 50 mg of omeprazole (group IV). Faecal fat excretion was evaluated before and after drug administration. Faecal fat excretion was reduced by 2.9 g (range, 1.7 to 5.0 g) in group I; 8.8 g (range, 2.9 to 39.9 g) in group II; 10.8 g (range, 2.3 to 21.8 g) in group III; and 4.3 g (range, 3.6 to 5.6 g) in group IV. The pancreatic digestive enzyme preparation was more effective than sodium bicarbonate and agents that raise the pH of the upper small intestine (such as proton-pump inhibitors) in reducing faecal fat excretion. The results indicate that all of the preparations used are effective against mild pancreatic steatorrhoea. If the condition is more advanced, however, a massive dosage of pancreatic digestive enzyme and possibly the combined use of an agent to raise the pH of the upper small intestine are likely to be effective.

Instrumentation and Control Systems for Sodium thermal hydraulic Experiment Loop for Finned-tube sodium-to-Air heat exchanger (SELFA)

Energy Technology Data Exchange (ETDEWEB)

Kim, Byeong Yeon; Kim, Hyung Mo; Cho, Youn Gil; Kim, Jong Man; Ko, Yung Joo; Kang, Byeong Su; Jung, Min Hwan; Jeong, Ji Young [KAERI, Daejeon (Korea, Republic of)

2016-05-15

A forced-draft sodium-to-air heat exchanger (FHX) is a part of decay heat removal system (DHRS) in Prototype Gen-IV Sodium-cooled fast reactor (PGSFR), which is being developed at Korea Atomic Energy Research Institute (KAERI). Sodium thermal hydraulic Experiment Loop for Finned-tube sodium-to-Air heat exchanger (SELFA) is a test facility for verification and validation of the design code for a forced-draft sodium-to-air heat exchanger (FHX). In this paper, we have provided design and fabrication features for the instrumentation and control systems of SELFA. In general, the instrumentation systems and control systems are coupled for measurement and control of process variables. Instrumentation systems have been designed for investigating thermal-hydraulic characteristics of FHX and control systems have been designed to control the main components (e.g. electromagnetic pumps, heaters, valves etc.) required for test in SELFA. In this paper, we have provided configurations of instrumentation and control systems for Sodium thermal hydraulic Experiment Loop for Finned-tube sodium-to-Air heat exchanger (SELFA). The instrumentation and control systems of SELFA have been implemented based on the expected operation ranges and lesson learned from operational experience of 'Sodium integral effect test loop for safety simulation and assessment-1' (STELLA-1)

Peaking cladding temperature and break equivalent size of intermediate break loss of coolant accident

International Nuclear Information System (INIS)

Luo Bangqi

2012-01-01

The analysis results of intermediate break loss of coolant accident for the nuclear power plant of million kw level showed to be as following: (1) At the begin of life, the break occur simultaneity reactor shutdown with L(X)P. it's equivalent break size and peaking cladding temperature is respectively 20 cm and 849℃. (2) At the begin of life, the break occur simultaneity reactor shutdown without loop. the reactor coolant pumps will be stop after reactor shutdown 10 minutes, it's equivalent break size and peaking cladding temperature is respectively 10.5 cm and 921℃. (3) At the bur up of 31 GWd/t(EOC1). the break occur simultaneity reactor shutdown without loop, the reactor coolant pumps will be stop after reactor shutdown 20 minutes, it's equivalent break size and peaking cladding temperature is respectively 8 cm and 1145℃. The above analysis results showed that the peaking cladding temperature of intermediate break loss of coolant accident is not only related with the break equivalent size and core bur up, and is closely related with the stop time of coolant pumps because the coolant pumps would drive the coolant from safety system to produce the seal loop in break loop and affect the core coolant flow, results in the fuel cladding temperature increasing or damaging. Therefore, the break spectrum, burn up spectrum, the stop time of coolant pumps and operator action time will need to detail analysis and provide appropriate operating procedure, otherwise the peaking cladding temperature will exceed 1204℃ and threaten the safety of the reactor core when the intermediate break loss of coolant accident occur in some break equivalent size, burn up, stop pumps time and operator action not appropriate. The pressurizer pressure low signal simultaneity containment pressure higher signal were used as the operator manual close the signal of reactor coolant pumps after reactor shutdown of 20 minutes. have successful solved the operator intervention time from 10 minutes

Optimized efflux assay for the NorA multidrug efflux pump in Staphylococcus aureus.

Science.gov (United States)

Zimmermann, Saskia; Tuchscherr, Lorena; Rödel, Jürgen; Löffler, Bettina; Bohnert, Jürgen A

2017-11-01

Real-time fluorescent efflux assays are commonly used for measuring the efflux of bacterial pumps. Here we describe an optimized protocol for the NorA efflux pump in S. aureus using DiOC 3 instead of ethidium bromide. Glucose and sodium formate were tested as energy carriers. This novel method is fast and reproducible. Copyright © 2017 Elsevier B.V. All rights reserved.

Site specific health and safety plan, 100-HR-3 pump and treat. Revision 1

International Nuclear Information System (INIS)

Tuttle, B.G.

1996-06-01

The 100-HR-3 Operable Unit encompasses groundwater contamination underlying the 100-D and 100-H Areas. The primary contaminate is chromium VI. The sources of chromium contamination resulted from the use of sodium dichromate during past reactor operations. The purpose of the 100-HR-3 Pump-and-Treat system is to pump contaminated groundwater through aboveground ion exchange resin and then return the treated waster to the aquifer. This plan covers operation, maintenance, repairs, and pump removal/installation

Monju secondary heat transport system sodium leak

International Nuclear Information System (INIS)

Suzuki, Takeo; Hiroi, Hiroshi; Usami, Shin; Iwata, Koji.

1996-01-01

On December 8, 1995, the sodium leakage from the secondary heat transport system (SHTS) occurred in the piping room of the reactor auxiliary building in Monju. The secondary sodium leaked through a temperature sensor, due to the breakaway of the tip of the well tube of the sensor installed near the outlet of the intermediate heat exchanger (IHX) in the C loop of SHTS. The reactor core remained cooled and thus, from the viewpoint of radiological hazards, the safety of the reactor was secured. There were no adverse effects for operating personnel or the surrounding environment. The cause of the well tube failure is considered to result from high cycle fatigue due to flow induced vibrations. Delay in draining the sodium from the leaking loop increased the consequential effects from sodium combustion products. (author)

Operating problem of low specific speed pumps operating in closed hydraulic loop

International Nuclear Information System (INIS)

Rajput, A.K.

1979-01-01

Results of the studies of pressure pulsations caused by the centrifugal pump driving a typical sodium test loop are presented. The method of characteristics has been used for solving the equations of unsteady fluid flow in closed hydraulic loops with various boundary points, important of which are pump, control valve and heater tank (acting hydraulically as surge tank). Mathematical and computational models used for calculations are described. (M.G.B.)

Hydrogen generation systems utilizing sodium silicide and sodium silica gel materials

Science.gov (United States)

Wallace, Andrew P.; Melack, John M.; Lefenfeld, Michael

2015-07-14

Systems, devices, and methods combine reactant materials and aqueous solutions to generate hydrogen. The reactant materials can sodium silicide or sodium silica gel. The hydrogen generation devices are used in fuels cells and other industrial applications. One system combines cooling, pumping, water storage, and other devices to sense and control reactions between reactant materials and aqueous solutions to generate hydrogen. Multiple inlets of varied placement geometries deliver aqueous solution to the reaction. The reactant materials and aqueous solution are churned to control the state of the reaction. The aqueous solution can be recycled and returned to the reaction. One system operates over a range of temperatures and pressures and includes a hydrogen separator, a heat removal mechanism, and state of reaction control devices. The systems, devices, and methods of generating hydrogen provide thermally stable solids, near-instant reaction with the aqueous solutions, and a non-toxic liquid by-product.

Sodium source development for pulsed power driven, photopumped NA/NE x-ray laser experiments

International Nuclear Information System (INIS)

Burkhalter, P.G.; Cooperstein, G.; Mosher, D.; Ottinger, P.F.; Scherrer, V.E.; Stephanakis, S.J.; Young, F.C.; Hinshelwood, D.D.; Mehlman, G.; Welch, B.L.; Jones, W.D.

1988-01-01

A sodium plasma source is being developed for a resonant photopumping x-ray laser scheme in which the 11A 1s 2 - 1s2rho 1 P 1 line in heliumlike Na X is used to pump the Ne IX n=4 singlet level. In their experiment the NRL Gamble II generator is used to produce two z-pinch plasmas in a side-by-side geometry. The sodium plasma is produced on axis and conducts the full 1 MA machine current. A fraction of this current returns through a neon gas puff located 5 cm from the sodium. This separation is determined by the need to prevent the plasmas from mixing and the need to have each plasma's azimuthal magnetic field as symmetric as possible. A minimum separation is desirable to increase coupling efficiency. To improve the pump source, a more confined source of pure sodium involving a coaxial plasma gun is being developed. They are currently studying both the operation of this source on a test stand and implosions of the resulting plasma on Gamble II. In initial experiments aluminum is substituted for sodium. Test stand diagnostics include photodiodes, witness plates, and current monitors designed to investigate the early motion of the annular plasma. Results from test stand and Gamble II experiments with both aluminum and sodium, as well as sodium handling techniques, are presented

Sodium cleaning device for nuclear reactor equipments

International Nuclear Information System (INIS)

Fujisawa, Morio.

1985-01-01

Purpose: To enable sodium cleaning over the entire length of large size equipments such as control rod drives and primary coolant recycling pumps for use in FBR type reactors. Constitution: A plurality of warm water supply nozzles each having a valve are connected at varying height on the side of a cleaning tank, to which an exhaust line is connected. These nozzles are connected with an exhaust port at the bottom of the tank to constitute a pipeway for cleaning warm water recycling line including a water feed pump and a feedwater heater. The water level in the tank is changed stepwise by successively selecting the warm water feed nozzles. Further, the warm water in the tank is recyclically fed through the nozzles selected at each step of the water level through the recycle line while warming. On the other hand, the pressure inside the tank is reduced through the exhaust line, whereby the warm water in the tank is boiled at low temperature to clean-up sodium on the equipments to be cleaned over the entire length. (Horiuchi, T.)

The Sodium-Potassium Pump Controls the Intrinsic Firing of the Cerebellar Purkinje Neuron

Science.gov (United States)

Forrest, Michael D.; Wall, Mark J.; Press, Daniel A.; Feng, Jianfeng

2012-01-01

In vitro, cerebellar Purkinje cells can intrinsically fire action potentials in a repeating trimodal or bimodal pattern. The trimodal pattern consists of tonic spiking, bursting, and quiescence. The bimodal pattern consists of tonic spiking and quiescence. It is unclear how these firing patterns are generated and what determines which firing pattern is selected. We have constructed a realistic biophysical Purkinje cell model that can replicate these patterns. In this model, Na+/K+ pump activity sets the Purkinje cell's operating mode. From rat cerebellar slices we present Purkinje whole cell recordings in the presence of ouabain, which irreversibly blocks the Na+/K+ pump. The model can replicate these recordings. We propose that Na+/K+ pump activity controls the intrinsic firing mode of cerbellar Purkinje cells. PMID:23284664

Exothermic potential of sodium nitrate salt cake

International Nuclear Information System (INIS)

Beitel, G.A.

1977-06-01

High-Level radioactive liquid waste is being reduced to a liquid slurry by an evaporation and crystallization process and stored in the existing single-shell tanks. Continuous pumping of the waste storage tank will reduce the present 30 to 50% moisture to the minimum possible. The reduced waste is a relatively immobile salt cake consisting predominantly of sodium nitrate (NaNO 3 ) with lesser amounts of sodium nitrite (NaNO 2 ), sodium metaaluminate (NaAlO 2 ), and sodium hydroxide (NaOH). Trace amounts of fission products, transuranics, and a broad spectrum of organic materials in small but unknown amounts are also present. A program was initiated in 1973 to determine whether or not conditions exist which could lead to an exothermic reaction in the salt cake. Results of the latest series of tests conducted to determine the effects of mass and pressure are summarized. Hanford salt cake, as stored, cannot support combustion, and does not ignite when covered with a burning volatile hydrocarbon

Effects of dietary sodium and the DASH diet on the occurrence of headaches: results from randomised multicentre DASH-Sodium clinical trial.

Science.gov (United States)

Amer, Muhammad; Woodward, Mark; Appel, Lawrence J

2014-12-11

Headaches are a common medical problem, yet few studies, particularly trials, have evaluated therapies that might prevent or control headaches. We, thus, investigated the effects on the occurrence of headaches of three levels of dietary sodium intake and two diet patterns (the Dietary Approaches to Stop Hypertension (DASH) diet (rich in fruits, vegetables and low-fat dairy products with reduced saturated and total fat) and a control diet (typical of Western consumption patterns)). Randomised multicentre clinical trial. Post hoc analyses of the DASH-Sodium trial in the USA. In a multicentre feeding study with three 30 day periods, 390 participants were randomised to the DASH or control diet. On their assigned diet, participants ate food with high sodium during one period, intermediate sodium during another period and low sodium during another period, in random order. Occurrence and severity of headache were ascertained from self-administered questionnaires, completed at the end of each feeding period. The occurrence of headaches was similar in DASH versus control, at high (OR (95% CI)=0.65 (0.37 to 1.12); p=0.12), intermediate (0.57 (0.29 to 1.12); p=0.10) and low (0.64 (0.36 to 1.13); p=0.12) sodium levels. By contrast, there was a lower risk of headache on the low, compared with high, sodium level, both on the control (0.69 (0.49 to 0.99); p=0.05) and DASH (0.69 (0.49 to 0.98); p=0.04) diets. A reduced sodium intake was associated with a significantly lower risk of headache, while dietary patterns had no effect on the risk of headaches in adults. Reduced dietary sodium intake offers a novel approach to prevent headaches. NCT00000608. 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.

Aerosol core nuclear reactor for space-based high energy/power nuclear-pumped lasers

International Nuclear Information System (INIS)

Prelas, M.A.; Boody, F.P.; Zediker, M.S.

1987-01-01

An aerosol core reactor concept can overcome the efficiency and/or chemical activity problems of other fuel-reactant interface concepts. In the design of a laser using the nuclear energy for a photon-intermediate pumping scheme, several features of the aerosol core reactor concept are attractive. First, the photon-intermediate pumping concept coupled with photon concentration methods and the aerosol fuel can provide the high power densities required to drive high energy/power lasers efficiently (about 25 to 100 kW/cu cm). Secondly, the intermediate photons should have relatively large mean free paths in the aerosol fuel which will allow the concept to scale more favorably. Finally, the aerosol core reactor concept can use materials which should allow the system to operate at high temperatures. An excimer laser pumped by the photons created in the fluorescer driven by a self-critical aerosol core reactor would have reasonable dimensions (finite cylinder of height 245 cm and radius of 245 cm), reasonable laser energy (1 MJ in approximately a 1 millisecond pulse), and reasonable mass (21 kg uranium, 8280 kg moderator, 460 kg fluorescer, 450 kg laser medium, and 3233 kg reflector). 12 references

Clinch River breeder reactor sodium fire protection system design and development

International Nuclear Information System (INIS)

Foster, K.W.; Boasso, C.J.; Kaushal, N.N.

1984-01-01

To assure the protection of the public and plant equipment, improbable accidents were hypothesized to form the basis for the design of safety systems. One such accident is the postulated failure of the Intermediate Heat Transfer System (IHTS) piping within the Steam Generator Building (SGB), resulting in a large-scale sodium fire. This paper discusses the design and development of plant features to reduce the consequences of the accident to acceptable levels. Additional design solutions were made to mitigate the sodium spray contribution to the accident scenario. Sodium spill tests demonstrated that large sodium leaks can be safely controlled in a sodium-cooled nuclear power plant

Magnetohydrodynamic instability in annular linear induction pump

International Nuclear Information System (INIS)

Araseki, Hideo; Kirillov, Igor R.; Preslitsky, Gennady V.; Ogorodnikov, Anatoly P.

2006-01-01

In the previous work, the authors showed some detailed aspects of the magnetohydrodynamic instability arising in an annular linear induction pump: the instability is accompanied with a low frequency pressure pulsation in the range of 0-10 Hz when the magnetic Reynolds number is larger than unity; the low frequency pressure pulsation is produced by the sodium vortices that come from some azimuthal non-uniformity of the applied magnetic field or of the sodium inlet velocity. In the present work, an experiment and a numerical analysis are carried out to verify the pump winding phase shift that is expected as an effective way to suppress the instability. The experimental data shows that the phase shift suppresses the instability unless the slip value is so high, but brings about a decrease of the developed pressure. The numerical results indicate that the phase shift causes a local decrease of the electromagnetic force, which results in the suppression of the instability and the decrease of the developed pressure. In addition, it is exhibited that the intensity of the double-supply-frequency pressure pulsation is in nearly the same level in the case with and without the phase shift

Evaluation of alternative fluids for SFR intermediate loops

International Nuclear Information System (INIS)

Brissonneau, L.; Simon, N.; Baque, F.

2009-01-01

Among the Generation IV systems, Sodium Fast Reactors (SFR) are promising and benefit of considerable technological experience, but improvements are researched on safety approach and capital cost reduction. One of the main drawback to be solved by the standard SFR design is the proper management of the risk of leakage between the intermediate circuit filled with sodium and the energy conversion system using a water Rankine cycle. The limitation of this risk requires notably an early detection of water leakage to prevent a water-sodium reaction. One innovative solution consists in the replacement of the sodium in the secondary loops by an alternative liquid fluid, not or less reactive with water. This alternative fluid might also allow innovative designs, e.g. intermediate heat exchanger and steam generator grouped in the same component. CEA, Areva NP and EdF have joined in a working group in order to evaluate different 'alternative fluids' that might replace sodium. A first selection retained seven fluids on the basis of 'required properties' as large operating range (low melting point, high boiling point ...), fluid cost and availability, acceptable corrosion at SFR working temperature. These are three bismuth alloys, two nitrate salts, one hydroxide melt and sodium with nanoparticles of nickel. Then, it was decided to evaluate these fluids through a multi-criteria analysis in order to quantify advantages and drawbacks of each fluid and to compare them with sodium. Lack of knowledge, impact on materials, design, working conditions and reactor availability should be emphasized by this analysis, in order to provide sound arguments for a research program on one or two promising fluids. A global note is given to each fluid by evaluating them with respect to 'grand criteria', weighted differently according to their importance. The grand criteria are : thermal properties, reactivity with structures, reactivity with other fluids (air, water, sodium), chemistry control

A reflux capsule steam generator for sodium cooled reactors

International Nuclear Information System (INIS)

Lantz, E.

Pressurized water reactor plants at numerous sites have sustained significant leakage through their steam generators. The consequent shutdowns for repairs and replacements have damaged their economics. This experience suggests that if steam generators for liquid metal fast breeder reactors (LMFBR's) continue to be built as presently designed some of them will have similar problems. Because of their larger capital investment, the consequent damage to the economics of LMFBR's could be more serious. Reflux capsules provide a way to separate sodium from water and to reduce thermal stresses in steam generators for sodium cooled reactors. Their use would also eliminate the need for a primary heat exchanger and a secondary sodium loop pump. (author)

Earthquake-proof support structures for the recycling pump in FBR type reactors

International Nuclear Information System (INIS)

Nakagawa, Masaki; Shigeta, Masayuki.

1984-01-01

Purpose: To improve the earthquake proofness of the recycling pump for use in FBR type reactors upon earthquake by reducing the vibration response of the pump. Constitution: The outer casing of a recycle pump suspended into liquid sodium is extended to the portion that penetrates a reactor core support structures. Support structures surrounding the outer side of the recycling pump are disposed with a gap not restraining the free thermal deformations of the recycling pump to the inside of the partition wall structures and the portion of the recycling pump penetrating the reator core support structures, to integrate the support structures with the reactor core support structures. Accordingly, there are no interferences between the recycling pump and the support structures with respect to the thermal deformations that change gradually with time. Upon vibrating under the rapidly changing external forces of earthquakes, however, the pressure resulted to the liquid in the gap due to the vibrations of the recycling pump is transmitted with no escape to the support structures, the recycling pump and the support structures integrally resist the vibrations thereby enabling to reduce the vibrations in the recycling pumps. (Horiuchi, T.)

A Design of He-Molten Salt Intermediate Heat Exchanger for VHTR

International Nuclear Information System (INIS)

Jeong, Hui Seong; Bang, Kwang Hyun

2010-01-01

The Very High Temperature Reactor (VHTR), one of the most challenging next generation nuclear reactors, has recently drawn an international interest due to its higher efficiency and the operating conditions adequate for supplying process heat to the hydrogen production facilities. To make the design of VHTR complete and plausible, the designs of the Intermediate Heat Transport Loop (IHTL) as well as the Intermediate Heat Exchanger (IHX) are known to be one of the difficult engineering tasks due to its high temperature operating condition (up to 950 .deg. C). A type of compact heat exchangers such as printed circuit heat exchanger (PCHE) has been recommended for the IHX in the technical and economical respects. Selection of the heat transporting fluid for the intermediate heat transport loop is important in consideration of safety and economical aspects. Although helium is currently the primary interest for the intermediate loop fluid, several safety concerns of gas fluids have been expressed. If the pressure boundary of the intermediate loop fails, the blowdown of the gas may overcool the reactor core and then the heat sink is lost after the blowdown. Also the large inventory of gas in the intermediate loop may leak into the primary side. There is also a recommendation that the nuclear plant and the hydrogen production plant be separated by a certain distance to ensure the safety of the nuclear plant in case of accidental heavy gas release from the chemical plant. In this circumstance, the pumping power of gas fluid in the intermediate loop will be large enough to degrade the economics of nuclear hydrogen.An alternative candidate for the intermediate loop fluid in consideration of these safety and economical problems of gas fluid can be molten salts. The Flinak molten salt, a eutectic mixture of LiF, NaF and KF (46.5:11.5:42.0 mole %) is considered to be a potential candidate for the heat transporting fluid in the IHTL due to its chemical stability against the

Na/K pump regulation of cardiac repolarization: insights from a systems biology approach

KAUST Repository

Bueno-Orovio, Alfonso; Sá nchez, Carlos; Pueyo, Esther; Rodriguez, Blanca

2013-01-01

gradients, crucial for cardiac cell electrophysiology. Importantly, sodium-potassium pump activity is impaired in a number of major diseased conditions, including ischemia and heart failure. However, its subtle ways of action on cardiac electrophysiology

Heat exchanger with intermediate evaporating and condensing fluid

International Nuclear Information System (INIS)

Fraas, A.P.

1978-01-01

A shell and tube-type heat exchanger, such as a liquid sodium-operated steam generator for use in nuclear reactors, comprises a shell containing a primary fluid tube bundle, a secondary fluid tube bundle at higher elevation, and an intermediate fluid vaporizing at the surface of the primary fluid tubes and condensing at the surface of the secondary fluid tubes

Experimental and numerical analysis of behavior of electromagnetic annular linear induction pump

International Nuclear Information System (INIS)

Goldsteins, Linards

2015-01-01

The research explores the issue of magnetohydrodynamic (MHD) instability in electromagnetic induction pumps with focus on the regimes of high slip Reynolds magnetic number (Rm s ) in Annular Linear Induction Pumps (ALIP) operating with liquid sodium. The context of the thesis is French GEN IV Sodium Fast Reactor research and development program for ASTRID in a framework of which the use of high discharge ALIP in the secondary cooling loops is being studied. CEA has designed, realized and will exploit PEMDYN facility, able to represent MHD instability in high discharge ALIP. In the thesis stability of an ideal ALIP is elaborated theoretically using linear stability analysis. Analysis revealed that strong amplification of perturbation is expected after convective stability threshold is reached. Theory is supported with numerical results and experiments reported in literature. Stable operation and stabilization technique operating with two frequencies in case of an ideal ALIP is discussed and necessary conditions derived. Detailed numerical models of flat linear induction pump (FLIP) taking into account effects of a real pump are developed. New technique of magnetic field measurements has been introduced and experimental results demonstrate a qualitative agreement with numerical models capturing all principal phenomena such as oscillation of magnetic field and perturbed velocity profiles. These results give significantly more profound insight in the phenomenon of MHD instability and can be used as a reference in further studies. (author) [fr

Numerical routine for magnetic heat pump cascading

DEFF Research Database (Denmark)

Filonenko, Konstantin; Lei, Tian; Engelbrecht, Kurt

Heat pumps use low-temperature heat absorbed from the energy source to create temperature gradient (TG) across the energy sink. Magnetic heat pumps (MHP) can perform this function through operating active magnetic regeneration (AMR) cycle. For building heating, TGs of up to a few K might...... and 3 K. Changing the number of MHPs, we optimized input parameters to achieve maximum heating powers. We have found that both maximum heating power and COP decrease together with number of heat pumps, but the TGs and the temperature span can be largely increased. References [1] M. Tahavori et al., “A...... be necessary, which is hardly achievable with a single MHP and such techniques as cascading are required. Series and parallel cascading increase the AMR span and heating power, respectively, but do not change TG. Therefore, the intermediate type of cascading was proposed with individual MHPs separately...

Hydrogen generation systems and methods utilizing sodium silicide and sodium silica gel materials

Energy Technology Data Exchange (ETDEWEB)

Wallace, Andrew P.; Melack, John M.; Lefenfeld, Michael

2017-12-19

Systems, devices, and methods combine thermally stable reactant materials and aqueous solutions to generate hydrogen and a non-toxic liquid by-product. The reactant materials can sodium silicide or sodium silica gel. The hydrogen generation devices are used in fuels cells and other industrial applications. One system combines cooling, pumping, water storage, and other devices to sense and control reactions between reactant materials and aqueous solutions to generate hydrogen. Springs and other pressurization mechanisms pressurize and deliver an aqueous solution to the reaction. A check valve and other pressure regulation mechanisms regulate the pressure of the aqueous solution delivered to the reactant fuel material in the reactor based upon characteristics of the pressurization mechanisms and can regulate the pressure of the delivered aqueous solution as a steady decay associated with the pressurization force. The pressure regulation mechanism can also prevent hydrogen gas from deflecting the pressure regulation mechanism.

The acoustic detection of cavitation in pumps

International Nuclear Information System (INIS)

Macleod, I.D.; Gray, B.S.; Taylor, C.G.

1978-01-01

A programme was initiated to develop a reliable technique for detecting the onset of acoustic noise from cavitation in a pump and to relate this to cavitation inception data, since significant noise from collapse of vapour bubbles arising from such cavitation would reduce the sensitivity of a noise detection system for boiling of sodium in fast breeder reactors. Factors affecting the detection of cavitation are discussed. The instrumentation and techniques of frequency analysis and pulse detection are described. Two examples are then given of the application of acoustic detection techniques under controlled conditions. It is concluded that acoustic detection can be a reliable method for detecting inception of cavitation in a pump and the required conditions are stated. (U.K.)

Flow in sodium loop surge tank

International Nuclear Information System (INIS)

Matal, O.; Martoch, J.

1977-01-01

The alternate liquid flow, the condition of vortex formation, gas entrainment in the discharge and the liquid level characteristics are studied using the models of the vertical and horizontal surge tanks of a sodium circuit with pump and heat exchangers. The conditions for vortex formation are more favourable in the vertical cylindrical tank than in the horizontal tank. The size of the vortex produced in the tank is affected by the initial speed circulation, due as a rule to an unsuitable inlet design. The proposed design considers an inlet below the sodium level using capped perforated pipes. Vortex formation, gas transport to the discharge pipe and turbulences of the liquid in the tank may be prevented by dividing the tank to the discharge and the inlet areas using perforated partitions, and by inserting the discharge cylinder above the discharge pipe outflow. The liquid level in the tank may be calmed by screens or by perforated plates. The adaptation of the surge tank of the sodium circuit will probably eliminate vortex formation and the entrainment of cover gas into the discharge piping and the sodium circuit under nominal conditions. (J.B.)

Modeling of fully coupled MHD flows in annular linear induction pumps

International Nuclear Information System (INIS)

Roman, C.; Dumont, M.; Letout, S.; Courtessole, C.; Fautrelle, Y.; Vitry, S.; Rey, F.

2014-01-01

The paper studies specific pumping characteristics of the Annular Linear Induction Pumps (ALIP) with travelling field for liquid sodium. The present work is focused on the analysis of very large electromagnetic pumps able to provide high flow rates. The magnetic Reynolds number is quite large, therefore, it is necessary to take into account the full magnetohydrodynamic interaction between the electromagnetic field and the liquid metal flow inside pump channel. We couple the electromagnetic aspects with the hydrodynamic ones by means of two commercial softwares. The geometry considered here is 2D axisymmetric. It is found that in such induction pumps the effect of convection is very important. Two main effects have been put forth. Firstly, due to the magnetic entrainment significant end effects are observed for large velocities. This leads to the existence of regions where the axial force is negative. Secondly, a Hartmann effect occurs near the walls. The electric current and the corresponding forces are confined near the wall in Hartmann layers. Global stability of e.m. pump is also analysed. (authors)

Towards an intermittency-friendly energy system: Comparing electric boilers and heat pumps in distributed cogeneration

International Nuclear Information System (INIS)

Blarke, Morten B.

2012-01-01

Highlights: ► We propose an “intermittency-friendly” energy system design. ► We compare intermittency-friendly concepts in distributed cogeneration. ► We investigate a new concept involving a heat pump and intermediate cold storage. ► We find significant improvements in operational intermittency-friendliness. ► Well-designed heat pump concepts are more cost-effective than electric boilers. -- Abstract: Distributed cogeneration has played a key role in the implementation of sustainable energy policies for three decades. However, increasing penetration levels of intermittent renewables is challenging that position. The paradigmatic case of West Denmark indicates that distributed operators are capitulating as wind power penetration levels are moving above 25%; some operators are retiring cogeneration units entirely, while other operators are making way for heat-only boilers. This development is jeopardizing the system-wide energy, economic, and environmental benefits that distributed cogeneration still has to offer. The solution is for distributed operators to adapt their technology and operational strategies to achieve a better co-existence between cogeneration and wind power. Four options for doing so are analysed including a new concept that integrates a high pressure compression heat pump using low-temperature heat recovered from flue gasses in combination with an intermediate cold storage, which enables the independent operation of heat pump and cogenerator. It is found that an electric boiler provides consistent improvements in the intermittency-friendliness of distributed cogeneration. However, well-designed heat pump concepts are more cost-effective than electric boilers, and in future markets where the gas/electricity price ratio is likely to increase, compression heat pumps in combination with intermediate thermal storages represent a superior potential for combining an intermittency-friendly pattern of operation with the efficient use of

Learning from real and tissue-engineered jellyfish: How to design and build a muscle-powered pump at intermediate Reynolds numbers

Science.gov (United States)

Nawroth, Janna; Lee, Hyungsuk; Feinberg, Adam; Ripplinger, Crystal; McCain, Megan; Grosberg, Anna; Dabiri, John; Parker, Kit

2012-11-01

Tissue-engineered devices promise to advance medical implants, aquatic robots and experimental platforms for tissue-fluid interactions. The design, fabrication and systematic improvement of tissue constructs, however, is challenging because of the complex interactions of living cell, synthetic materials and their fluid environments. In a proof of concept study we have tissue-engineered a construct that mimics the swimming of a juvenile jellyfish, a simple model system for muscle-powered pumps at intermediate Reynolds numbers with quantifiable fluid dynamics and morphological properties. Optimally designed constructs achieved jellyfish-like swimming and generated biomimetic propulsion and feeding currents. Focusing on the fluid interactions, we discuss failed and successful designs and the lessons learned in the process. The main challenges were (1) to derive a body shape and deformation suitable for effective fluid transport under physiological fluid conditions, (2) to understand the mechanical properties of muscle and bell matrix and device a design capable of the desired deformation, (3) to establish adequate 3D kinematics of power and recovery stroke, and (4) to evaluate the performance of the design.

Wastage of Steam Generator Tubes by Sodium-Water Reaction

International Nuclear Information System (INIS)

Jeong, Ji Young; Kim, Jong Man; Kim, Tae Joon; Choi, Jong Hyeun; Kim, Byung Ho; Lee, Yong Bum; Park, Nam Cook

2010-01-01

The Korea Advanced LIquid MEtal Reactor (KALIMER) steam generator is a helical coil, vertically oriented, shell-and-tube type heat exchanger with fixed tube-sheet. The conceptual design and outline drawing of the steam generator are shown in Figure 1. Flow is counter-current, with sodium on the shell side and water/steam on the tube side. Sodium flow enters the steam generator through the upper inlet nozzles and then flows down through the tube bundle. Feedwater enters the steam generator through the feedwater nozzles at the bottom of steam generator. Therefore, if there is a hole or a crack in a heat transfer tube, a leakage of water/steam into the sodium may occur, resulting in a sodium-water reaction. When such a leak occurs, so-called 'wastage' is the result which may cause damage to or a failure of the adjacent tubes. If a steam generator is operated for some time in this condition, it is possible that it might create an intermediate leak state which would then give rise to the problems of a multi-target wastage in a very short time. Therefore, it is very important to predict these phenomena quantitatively from the view of designing a steam generator and its leak detection systems. For this, multi-target wastage tests for modified 9Cr-1Mo steel tube bundle by intermediate leaks are being prepared

Final report on the safety assessment of sodium sulfite, potassium sulfite, ammonium sulfite, sodium bisulfite, ammonium bisulfite, sodium metabisulfite and potassium metabisulfite.

Science.gov (United States)

Nair, Bindu; Elmore, Amy R

2003-01-01

Sodium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Potassium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite are inorganic salts that function as reducing agents in cosmetic formulations. All except Sodium Metabisulfite also function as hair-waving/straightening agents. In addition, Sodium Sulfite, Potassium Sulfite, Sodium Bisulfite, and Sodium Metabisulfite function as antioxidants. Although Ammonium Sulfite is not in current use, the others are widely used in hair care products. Sulfites that enter mammals via ingestion, inhalation, or injection are metabolized by sulfite oxidase to sulfate. In oral-dose animal toxicity studies, hyperplastic changes in the gastric mucosa were the most common findings at high doses. Ammonium Sulfite aerosol had an acute LC(50) of >400 mg/m(3) in guinea pigs. A single exposure to low concentrations of a Sodium Sulfite fine aerosol produced dose-related changes in the lung capacity parameters of guinea pigs. A 3-day exposure of rats to a Sodium Sulfite fine aerosol produced mild pulmonary edema and irritation of the tracheal epithelium. Severe epithelial changes were observed in dogs exposed for 290 days to 1 mg/m(3) of a Sodium Metabisulfite fine aerosol. These fine aerosols contained fine respirable particle sizes that are not found in cosmetic aerosols or pump sprays. None of the cosmetic product types, however, in which these ingredients are used are aerosolized. Sodium Bisulfite (tested at 38%) and Sodium Metabisulfite (undiluted) were not irritants to rabbits following occlusive exposures. Sodium Metabisulfite (tested at 50%) was irritating to guinea pigs following repeated exposure. In rats, Sodium Sulfite heptahydrate at large doses (up to 3.3 g/kg) produced fetal toxicity but not teratogenicity. Sodium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite were not teratogenic for mice, rats, hamsters, or rabbits at doses up to 160 mg/kg. Generally, Sodium Sulfite, Sodium

Crystalline maricite NaFePO4 as a positive electrode material for sodium secondary batteries operating at intermediate temperature

Science.gov (United States)

Hwang, Jinkwang; Matsumoto, Kazuhiko; Orikasa, Yuki; Katayama, Misaki; Inada, Yasuhiro; Nohira, Toshiyuki; Hagiwara, Rika

2018-02-01

Maricite NaFePO4 (m-NaFePO4) was investigated as a positive electrode material for intermediate-temperature operation of sodium secondary batteries using ionic liquid electrolytes. Powdered m-NaFePO4 was prepared by a conventional solid-state method at 873 K and subsequently fabricated in two different conditions; one is ball-milled in acetone and the other is re-calcined at 873 K after the ball-milling. Electrochemical properties of the electrodes prepared with the as-synthesized m-NaFePO4, the ball-milled m-NaFePO4, and the re-calcined m-NaFePO4 were investigated in Na[FSA]-[C2C1im][FSA] (C2C1im+ = 1-ethyl-3-methylimidazolium, FSA- = bis(fluorosulfonyl)amide) ionic liquid electrolytes at 298 K and 363 K to assess the effects of temperature and particle size on their electrochemical properties. A reversible charge-discharge capacity of 107 mAh g-1 was achieved with a coulombic efficiency >98% from the 2nd cycle using the ball-milled m-NaFePO4 electrode at a C-rate of 0.1 C and 363 K. Electrochemical impedance spectroscopy using m-NaFePO4/m-NaFePO4 symmetric cells indicated that inactive m-NaFePO4 becomes an active material through ball-milling treatment and elevation of operating temperature. X-ray diffraction analysis of crystalline m-NaFePO4 confirmed the lattice contraction and expansion upon charging and discharging, respectively. These results indicate that the desodiation-sodiation process in m-NaFePO4 is reversible in the intermediate-temperature range.

Sodium leak at Monju (I): Cause and consequences

International Nuclear Information System (INIS)

Mikami, H.; Shono, A.; Hiroi, H.

1996-01-01

On December 8, 1995, a sodium leak from the Secondary Heat Transport System (SHTS) occurred in a piping room of the reactor auxiliary building at Monju. The sodium leaked through a thermocouple temperature sensor due to the breakage of the well tube of the sensor installed near the outlet of the Intermediate Heat Exchanger (IHX) in SHTS Loop C. There were no adverse effects for operating personnel or the surrounding environment. The reactor core remained cooled and thus, from the viewpoint of radiological hazards, the safety of the reactor was secured. On the basis of the investigations, it was concluded that the breakage of the thermocouple well was caused by high cycle fatigue due to flow induced vibration in the direction of sodium flow. (author)

Compatibility of steels for fast breeder reactor in high temperature sodium

International Nuclear Information System (INIS)

Yuhara, Shunichi

1981-01-01

In recent years, considerable progress has been made and experience has been obtained for material applicability in sodium-cooled fast breeder reactors. In this report, materials, principal dimensions and sodium conditions for the reactor system components, which include fuel pin cladding, intermediate heat exchangers, steam generators and pipings, are reviewed with emphasis on the thin-walled, high temperature and high strength components. The corrosion, mechanical and tribological behavior in sodium of important materials used for the reactor components, such as Types 304 and 316 stainless steel and 2 1/4Cr-1Mo steel, are discussed on the basis of characteristic testing results. Furthermore, material requirements concerned with compatibility in sodium are summarized from this review and discussion. (author)

Using Composite Materials in a Cryogenic Pump

Science.gov (United States)

Batton, William D.; Dillard, James E.; Rottmund, Matthew E.; Tupper, Michael L.; Mallick, Kaushik; Francis, William H.

2008-01-01

Several modifications have been made to the design and operation of an extended-shaft cryogenic pump to increase the efficiency of pumping. In general, the efficiency of pumping a cryogenic fluid is limited by thermal losses which is itself caused by pump inefficiency and leakage of heat through the pump structure. A typical cryogenic pump includes a drive shaft and two main concentric static components (an outer pressure containment tube and an intermediate static support tube) made from stainless steel. The modifications made include replacement of the stainless-steel drive shaft and the concentric static stainless-steel components with components made of a glass/epoxy composite. The leakage of heat is thus reduced because the thermal conductivity of the composite is an order of magnitude below that of stainless steel. Taking advantage of the margin afforded by the decrease in thermal conductivity, the drive shaft could be shortened to increase its effective stiffness, thereby increasing the rotordynamic critical speeds, thereby further making it possible to operate the pump at a higher speed to increase pumping efficiency. During the modification effort, an analysis revealed that substitution of the shorter glass/epoxy shaft for the longer stainless-steel shaft was not, by itself, sufficient to satisfy the rotordynamic requirements at the desired increased speed. Hence, it became necessary to increase the stiffness of the composite shaft. This stiffening was accomplished by means of a carbon-fiber-composite overwrap along most of the length of the shaft. Concomitantly with the modifications described thus far, it was necessary to provide for joining the composite-material components with metallic components required by different aspects of the pump design. An adhesive material formulated specially to bond the composite and metal components was chosen as a means to satisfy these requirements.

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

Sodium temperature/wind lidar based on laser-diode-pumped Nd:YAG lasers deployed at Tromsø, Norway (69.6°N, 19.2°E).

Science.gov (United States)

Kawahara, T D; Nozawa, S; Saito, N; Kawabata, T; Tsuda, T T; Wada, S

2017-06-12

An Nd:YAG laser-based sodium temperature/wind lidar was developed for the measurement of the northern polar mesosphere and lower thermosphere at Tromsø (69.6N, 19.2E), Norway. Coherent light at 589 nm is produced by sum frequency generation of 1064 nm and 1319 nm from two diode laser end-pumped pulsed Nd:YAG lasers. The output power is as high as 4W, with 4 mJ/pulse at 1000 Hz repetition rate. Five tilting Cassegrain telescopes enable us to make five-direction (zenith, north, south, east, west) observation for temperature and wind simultaneously. This highly stable laser system is first of its kind to operate virtually maintenance-free during the observation season (from late September to March) since 2010.

Status of sodium boiling noise detection programme at reactor research centre, India

Energy Technology Data Exchange (ETDEWEB)

Prabhakar, R; Elumalai, G [Reactor Engineering Laboratory, Reactor Research Centre, Chingleput, Tamil Nadu (India)

1982-01-01

Acoustic detection of sodium boiling is a promising technique to monitor subassembly fault in a last reactor. This paper summarises the programme for developing this detection system and describes the design of a high temperature transducer for boiling detection. It is appreciated that the background noise from primary pumps can interfere with this detection. Noise measurements were therefore carried out during water testing of the primary pump of the Fast Breeder Test Reactor. Some preliminary results of these measurements are presented.

Status of sodium boiling noise detection programme at reactor research centre, India

International Nuclear Information System (INIS)

Prabhakar, R.; Elumalai, G.

1982-01-01

Acoustic detection of sodium boiling is a promising technique to monitor subassembly fault in a last reactor. This paper summarises the programme for developing this detection system and describes the design of a high temperature transducer for boiling detection. It is appreciated that the background noise from primary pumps can interfere with this detection. Noise measurements were therefore carried out during water testing of the primary pump of the Fast Breeder Test Reactor. Some preliminary results of these measurements are presented

Effect of carbon activity on the creep behaviour of 21/4Cr, 1Mo steel in sodium

International Nuclear Information System (INIS)

Cordwell, J.E.; Charnock, W.; Nicholson, R.D.

1979-02-01

The creep endurance and creep cracking behaviour of 2 1/4Cr, 1Mo steel in sodium at 475 0 C have been studied at three different sodium carbon activities. Creep endurance was found to increase with increasing carbon activity of the sodium. Tests carried out in high carbon activity sodium were discontinued before fracture. Creep crack initiation displacement at notches decreased with increasing carbon activity, presumably as a result of notch tip carburisation. The plastic zones at the tips of blunt notches in specimens exposed in high carbon activity sodium were preferentially carburised. These observations were similar to those made previously on 9Cr, 1Mo steel. One difference detected metallographically was that in a high carburising environment uniform carburisation was obtained in the 2 1/4Cr, 1Mo steel specimens whereas carburisation gradients were observed in the 9Cr, 1Mo steel. Creep crack propagation rates for given notch opening displacement rates in low and intermediate carbon activity sodium were indistinguishable. However, the strenthening that resulted from the mild carburisation of the specimen in the intermediate carbon activity sodium caused slower notch opening displacement rates and crack propagation rates than in the low carbon activity sodium, when the rates were compared at the same crack length. (author)

Altered erythrocyte Na-K pump in anorectic patients

Energy Technology Data Exchange (ETDEWEB)

Pasquali, R.; Strocchi, E.; Malini, P.; Casimirri, F.; Ambrosioni, E.; Melchionda, N.; Labo, G.

1985-07-01

The status of the erythrocyte sodium pump was evaluated in a group of patients suffering from anorexia nervosa and a group of healthy female control subjects. Anorectic patients showed significantly higher mean values of digoxin-binding sites/cell (ie, the number of Na-K-ATPase units) with respect to control subjects while no differences were found in the specific /sup 86/Rb uptake (which reflects the Na-K-ATPase activity) between the two groups. A significant correlation was found between relative weight and the number of Na-K-ATPase pump units (r = -0.66; P less than 0.0001). Anorectic patients showed lower serum T3 concentrations (71.3 +/- 53 ng/dL) with respect to control subjects (100.8 +/- 4.7 ng/dL; P less than 0.0005) and a significant negative correlation between T3 levels and the number of pump units (r = -0.52; P less than 0.003) was found. This study therefore shows that the erythrocyte Na-K pump may be altered in several anorectic patients. The authors suggest that this feature could be interrelated with the degree of underweight and/or malnutrition.

Altered erythrocyte Na-K pump in anorectic patients

International Nuclear Information System (INIS)

Pasquali, R.; Strocchi, E.; Malini, P.; Casimirri, F.; Ambrosioni, E.; Melchionda, N.; Labo, G.

1985-01-01

The status of the erythrocyte sodium pump was evaluated in a group of patients suffering from anorexia nervosa and a group of healthy female control subjects. Anorectic patients showed significantly higher mean values of digoxin-binding sites/cell (ie, the number of Na-K-ATPase units) with respect to control subjects while no differences were found in the specific 86 Rb uptake (which reflects the Na-K-ATPase activity) between the two groups. A significant correlation was found between relative weight and the number of Na-K-ATPase pump units (r = -0.66; P less than 0.0001). Anorectic patients showed lower serum T3 concentrations (71.3 +/- 53 ng/dL) with respect to control subjects (100.8 +/- 4.7 ng/dL; P less than 0.0005) and a significant negative correlation between T3 levels and the number of pump units (r = -0.52; P less than 0.003) was found. This study therefore shows that the erythrocyte Na-K pump may be altered in several anorectic patients. The authors suggest that this feature could be interrelated with the degree of underweight and/or malnutrition

Prediction of EMP cavitation threshold from other than sodium testing

International Nuclear Information System (INIS)

Kambe, M.; Kamei, M.

2002-01-01

An experimental study has been performed to predict the cavitation threshold of electromagnetic pumps from measurements on test models using water and alcohol. Cavitation tests were carried out using water and alcohol test loop on subscale ducts of transparent acrylic resin with reference to an actual pump (1.1m 3 /min). These data were compared to those obtained from the in-sodium tests on the actual pump. The investigation revealed that the value of Thoma's dimensionless parameter: σ applied to the test model for water and alcohol is quite higher than that of corresponding σ on the actual pump. To minimize the incipient cavitation safety margin, more accurate prediction must be required. In view of this, the authors proposed the dimensionless parameter: σ T =σ/W-bare where W-bare denotes the Weber number. This parameter was confirmed to predict the cavitation threshold of electromagnetic pumps with much more accuracy than ever before. It can also be adopted to predict cavitation threshold of other FBR components. (author)

Development of sputter ion pump based SG leak detection system for Fast Breeder Test Reactor

International Nuclear Information System (INIS)

Babu, B.; Sureshkumar, K.V.; Srinivasan, G.

2013-01-01

Highlights: ► Development and commissioning of SG leak detection system for FBTR. ► Development of Robust method of using sputter ion pump based system. ► Modifications for improving reliability and availability. ► On line injection of hydrogen in sodium during reactor operation. ► Triplication of the SG leak detection system. - Abstract: The Fast Breeder Test Reactor (FBTR) is a 40 MWt, loop type sodium cooled fast reactor built at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam as a fore-runner to the second stage of Indian nuclear power programme. The reactor design is based on the French reactor Rapsodie with several modifications which include the provision of a steam-water circuit and turbo-generator. FBTR uses sodium as the coolant in the main heat transport medium to transfer heat from the reactor core to the feed water in the tertiary loop for producing superheated steam, which drives the turbo-generator. Sodium and water flow in shell and tube side respectively, separated by thin-walls of the ferritic steel tubes of the once-through steam generator (SG). Material defects in these tubes can lead to leakage of water into sodium, resulting in sodium water reactions leading to undesirable consequences. Early detection of water or steam leaks into sodium in the steam generator units of liquid metal fast breeder reactors (LMFBR) is an important requirement from safety and economic considerations. The SG leak in FBTR is detected by Sputter Ion Pump (SIP) based Steam Generator Leak Detection (SGLD) system and Thermal Conductivity Detector (TCD) based Hydrogen in Argon Detection (HAD) system. Many modifications were carried out in the SGLD system for the reactor operation to improve the reliability and availability. This paper details the development and the acquired experience of SIP based SGLD system instrumentation for real time hydrogen detection in sodium for FBTR.

Mechanistic approach to the sodium leakage and fire analysis

International Nuclear Information System (INIS)

Yamaguchi, Akira; Muramatsu, Toshiharu; Ohira, Hiroaki; Ida, Masao

1997-04-01

In December 1995, a thermocouple well was broken and liquid sodium leaked out of the intermediate heat transport system of the prototype fast breeder reactor Monju. In the initiating process of the incident, liquid sodium flowed out through the hollow thermocouple well, nipple and connector. As a result, liquid sodium, following ignition and combustion, was dropping from the connector to colide with the duct and grating placed below. The collision may cause fragmentation and scattering of the sodium droplet that finally was piled up on the floor. This report deals with the development of computer programs for the phenomena based on mechanistics approach. Numerical analyses are also made for fundamental sodium leakage and combustion phenomenon, sodium combustion experiment, and Monju incident condition. The contents of this report is listed below: (1) Analysis of chemical reaction process based on molecular orbital method, (2) Thermalhy draulic analysis of the sodium combustion experiment II performed in 1996 at O-arai Engineering Center, PNC, (3) Thermalhy draulic analysis of room A-446 of Monju reactor when the sodium leakage took place, (4) Direct numerical simulation of sodium droplet, (5) Sodium leakage and scattering analysis using three dimensional particle method, (6) Multi-dimensional combustion analysis and multi-point approximation combustion analysis code. Subsequent to the development work of the programs, they are to be applied to the safety analysis of the Fast Breeder Reactor. (author)

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

Sodium-water clusters and their role in radiation chemistry

International Nuclear Information System (INIS)

Dhar, S.; Kestner, N.R.

1988-01-01

Studies of sodium-water clusters are presented which could serve as models for the recently suggested intermediate species in the radiation chemistry of water. The ionization potentials and the lower excited states of sodium with n-water molecules are calculated by ab initio quantum chemistry methods. The ionization potential calculated at the SCF level for the water monomer is 4.10 eV, which becomes 4.34 at the MP2 correlation level. The experimental value is 4.379 ± 0.002 eV. Structural data is presented for the lower members of the sodium with n-water clusters. In addition the Hartree-Fock calculations indicate that there should be some strong charge transfer to solvent transitions at higher energies. (author)

The design and commissioning of cold trap purifying system of hydrogen meter sodium loop

International Nuclear Information System (INIS)

Zhao Zhaoyi; Jia Baoshan; Chen Xiaoming; Pan Fengguo

1993-01-01

The design feature and parameters of cold trap purifying system of hydrogen meter sodium loop and its commissioning results are reported and discussed. In order to adjust the flow easily,. the cold trap purifying system is arranged in the exit of the electromagnetic pump. It is composed of regenerator and the cold trap. The regenerator is above the cold trap. The high temperature sodium in the main-loop flows through the regenerator, in the entrance of the cold trap, its temperature is reduced to 180 degree C. After entering into the cold trap, the sodium flows to the purifying region by side, when it arrives the bottom of the trap, its temperature is reduced to 110 degree C. The cold trap is cooled by air. The temperature of the clean sodium rises nearby the main-loop's by the regenerator, and then it returns to the entrance of the electromagnetic pump. According to the commissioning results, the sodium's temperature of the cold trap could be reduced to 110 degree C by reducing the flow of the cold trap purifying system and the temperature of the main-loop, or increasing the air flow and cutting off the power supply of its heating. The authors think that the latter is more conformable with the design stipulation and with the requirement of the hydrogen meter experiment, and it can meet the requirements of the operation of the Nuclear Power Plant

Continuous Flow-Resonance Raman Spectroscopy of an Intermediate Redox State of Cytochrome-C

DEFF Research Database (Denmark)

Forster, M.; Hester, R. E.; Cartling, B.

1982-01-01

An intermediate redox state of cytochrome c at alkaline pH, generated upon rapid reduction by sodium dithionite, has been observed by resonance Raman (RR) spectroscopy in combination with the continuous flow technique. The RR spectrum of the intermediate state is reported for excitation both...... in the (alpha, beta) and the Soret optical absorption band. The spectra of the intermediate state are more like those of the stable reduced form than those of the stable oxidized form. For excitation of 514.5 nm, the most prominent indication of an intermediate state is the wave-number shift of one RR band from...... 1,562 cm-1 in the stable oxidized state through 1,535 cm-1 in the intermediate state to 1,544 cm-1 in the stable reduced state. For excitation at 413.1 nm, a band, present at 1,542 cm-1 in the stable reduced state but not present in the stable oxidized state, is absent in the intermediate state. We...

Multi-Temperature Heat Pump with Cascade Compressor Connection

Directory of Open Access Journals (Sweden)

Sit M.L.

2017-08-01

Full Text Available The object of the study is a multifunctional heat pump with several evaporators and condensers designed for simultaneous provision of technological processes with heat and cold. The aim of the work is the development and study of the scheme for this type of heat pumps, which ensures minimum irreversibility in the "compressor-gas coolers" chain, without the use of adjustable ejectors installed after evaporators and used as flow mixers. The obtained technical solution ensures the stabilization of the heat pump coefficient of performance (COP and prescribed thermal regimes of heat exchangers at a variable flow rate of the refrigerant. The novelty of the elaboration is inclusion a compressor of the first stage with a serially connected intermediate heat exchanger and a control valve that are located before the compressor inlet of the second stage of the heat pump, which allows to establish a rational pressure after the first stage of the compressors. A scheme is proposed for regulating the temperature at the inlet of the first stage compressors by regulating the flow through the primary circuits of the recuperative heat exchangers. The first stage compressor control system allows providing the required modes of operation of the heat pump. It is established, because of the exergetic analysis of the sections of the hydraulic circuit of heat pump located between the evaporators and gas coolers that the reduction of irreversible losses in the heat pump is ensured due to the optimal choice of the superheat value of the gas after the evaporators.

Similarity rules of thermal stratification phenomena for water and sodium

International Nuclear Information System (INIS)

Ohtsuka, M.; Ikeda, T.; Yamakawa, M.; Shibata, Y.; Moriya, S.; Ushijima, S.; Fujimoto, K.

1988-01-01

Similarity rules for thermal stratification phenomena were studied using sodium and water experiments with scaled cylindrical vessels. The vessel dimensions were identical to focus on the effect of differences in fluid properties upon the phenomena. Comparisons of test results between sodium and water elucidated similar and dissimilar characteristics for thermal stratification phenomena which appeared in the scaled vessels. Results were as follows: (1) The dimensionless upward velocity of the thermal stratification interface was proportional to Ri -0.74 for water and sodium during the period when the buoyancy effect was dominant. (2) Dimensionless temperature transient rate at the outlet slit decreased with Ri for sodium and remained constant for water where Ri>0.2. The applicability of the scaled test results to an actual power plant was also studied by using multi-dimensional numerical analysis which was verified by the water and sodium experiments. Water experiments could simulate liquid metal fast breeder reactor flows more accurately than sodium experiments for dimensionless temperature gradient at the thermal stratification interface and dimensionless temperature transient rate at the intermediate heat exchanger inlet

Validation of intermediate heat and decay heat exchanger model in MARS-LMR with STELLA-1 and JOYO tests

Energy Technology Data Exchange (ETDEWEB)

Choi, Chiwoong; Ha, Kwiseok; Hong, Jonggan; Yeom, Sujin; Eoh, Jaehyuk [Sodium-cooled Fast Reactor Design Division, Korea Atomic Energy Research Institute (KAERI), 989-111, Daedeok-Daero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Jeong, Hae-yong, E-mail: hyjeong@sejong.ac.kr [Department of Nuclear Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 143-747 (Korea, Republic of)

2016-11-15

Highlights: • The capability of the MARS-LMR for heat transfer through IHX and DHX is evaluated. • Prediction of heat transfer through IHXs and DHXs is essential in the SFR analysis. • Data obtained from the STELLA-1 and the JOYO test are analyzed with the MARS-LMR. • MARS-LMR adopts the Aoki’s correlation for tube side and Graber-Rieger’s for shell. • The performance of the basic models and other available correlations is evaluated. • The current models in MARS-LMR show best prediction for JOYO and STELLA-1 data. - Abstract: The MARS-LMR code has been developed by the Korea Atomic Energy Research Institute (KAERI) to analyze transients in a pool-type sodium-cooled fast reactor (SFR). Currently, KAERI is developing a prototype Gen-IV SFR (PGSFR) with metallic fuel. The decay heat exchangers (DHXs) and the intermediate heat exchangers (IHXs) were designed as a sodium-sodium counter-flow tube bundle type for decay heat removal system (DHRS) and intermediate heat transport system (IHTS), respectively. The IHX and DHX are important components for a heat removal function under normal and accident conditions, respectively. Therefore, sodium heat transfer models for the DHX and IHX heat exchangers were added in MARS-LMR. In order to validate the newly added heat transfer model, experimental data were obtained from the JOYO and STELLA-1 facilities were analyzed. JOYO has two different types of IHXs: type-A (co-axial circular arrangement) and type-B (triangular arrangement). For the code validation, 38 and 39 data points for type A and type B were selected, respectively. A DHX performance test was conducted in STELLA-1, which is the test facility for heat exchangers and primary pump in the PGSFR. The DHX test in STELLA-1 provided eight data points for a code validation. Ten nodes are used in the heat transfer region is used, based on the verification test for the heat transfer models. RMS errors for JOYO IHX type A and type B of 19.1% and 4.3% are obtained

Hypothesized diprotomeric enzyme complex supported by stochastic modelling of palytoxin-induced Na/K pump channels.

Science.gov (United States)

Vilallonga, Gabriel D; de Almeida, Antônio-Carlos G; Ribeiro, Kelison T; Campos, Sergio V A; Rodrigues, Antônio M

2018-03-01

The sodium-potassium pump (Na + /K + pump) is crucial for cell physiology. Despite great advances in the understanding of this ionic pumping system, its mechanism is not completely understood. We propose the use of a statistical model checker to investigate palytoxin (PTX)-induced Na + /K + pump channels. We modelled a system of reactions representing transitions between the conformational substates of the channel with parameters, concentrations of the substates and reaction rates extracted from simulations reported in the literature, based on electrophysiological recordings in a whole-cell configuration. The model was implemented using the UPPAAL-SMC platform. Comparing simulations and probabilistic queries from stochastic system semantics with experimental data, it was possible to propose additional reactions to reproduce the single-channel dynamic. The probabilistic analyses and simulations suggest that the PTX-induced Na + /K + pump channel functions as a diprotomeric complex in which protein-protein interactions increase the affinity of the Na + /K + pump for PTX.

RND multidrug efflux pumps: what are they good for?

Science.gov (United States)

Alvarez-Ortega, Carolina; Olivares, Jorge; Martínez, José L.

2013-01-01

Multidrug efflux pumps are chromosomally encoded genetic elements capable of mediating resistance to toxic compounds in several life forms. In bacteria, these elements are involved in intrinsic and acquired resistance to antibiotics. Unlike other well-known horizontally acquired antibiotic resistance determinants, genes encoding for multidrug efflux pumps belong to the core of bacterial genomes and thus have evolved over millions of years. The selective pressure stemming from the use of antibiotics to treat bacterial infections is relatively recent in evolutionary terms. Therefore, it is unlikely that these elements have evolved in response to antibiotics. In the last years, several studies have identified numerous functions for efflux pumps that go beyond antibiotic extrusion. In this review we present some examples of these functions that range from bacterial interactions with plant or animal hosts, to the detoxification of metabolic intermediates or the maintenance of cellular homeostasis. PMID:23386844

Mode and Intermediate Waters in Earth System Models

Energy Technology Data Exchange (ETDEWEB)

Gnanadesikan, Anand [Johns Hopkins Univ., Baltimore, MD (United States); Sarmiento, Jorge L. [Princeton Univ., NJ (United States)

2015-12-22

This report describes work done as part of a joint Princeton-Johns Hopkins project to look at the impact of mode and intermediate waters in Earth System Models. The Johns Hopkins portion of this work focussed on the role of lateral mixing in ventilating such waters, with important implications for hypoxia, the uptake of anthropogenic carbon, the dynamics of El Nino and carbon pumps. The Johns Hopkins group also collaborated with the Princeton Group to help develop a watermass diagnostics framework.

Preliminary conceptual design of the secondary sodium circuit-eliminated JSFR (Japan Sodium Fast Reactor) adopting a supercritical CO2 turbine system (1). Sodium/CO2 heat exchanger

International Nuclear Information System (INIS)

Kisohara, Naoyuki; Sakamoto, Yoshihiko; Kotake, Shoji

2014-09-01

Research and development of the supercritical CO 2 (S-CO 2 ) cycle turbine system is underway in various countries for further improvement of the safety and economy of sodium-cooled fast reactors. The Component Design and Balance-Of-Plant (CD and BOP) of the Generation IV International Nuclear Forum (Gen-IV) has addressed this study, and their analytical and experimental results have been discussed between the relevant countries. JAEA, who is a member of the CD and BOP, has performed a design study of an S-CO 2 gas turbine system applied to the Japan Sodium-cooled Fast Reactor (JSFR). In this study, the S-CO 2 cycle turbine system was directly connected to the primary sodium system of the JSFR to eliminate the secondary sodium circuit, aiming for further economical improvement. This is because there is no risk of sodium-water reaction in the S-CO 2 cycle turbine system of SFRs. The Na/CO 2 heat exchanger is one of the key components for the secondary sodium system eliminated SFR, and this report describes its structure and the safety in case of CO 2 leak. A Printed Circuit Heat Exchanger (PCHE), which has a greater heat transfer performance, is employed to the heat exchanger. Another advantage of the PCHE is to limit the area affected by a leak of CO 2 because of its partitioned flow path structure. A SiC/SiC ceramic composite material is used for the PCHE to prevent crack growth and to reduce thermal stress. The Na/CO 2 heat exchanger has been designed in such a way that a number of small heat transfer modules are combined in the vessel in consideration of manufacture and repair. The primary sodium pump is installed in the center of the heat exchanger vessel. CO 2 leak events in the heat exchanger have been also evaluated, and it revealed that no significant effect has arisen on the core or the primary sodium boundary. (author)

Effect of dietary sodium on the Na-K ATPase inhibitor in patients with essential hypertension

International Nuclear Information System (INIS)

Ashida, T.; Kuramochi, M.; Kojima, S.

1989-01-01

To study the circulating humoral factor modifying transmembrane sodium transport, plasma was obtained from 12 patients with essential hypertension (EH) fed a high sodium diet (NaCl 15 to 17 g/d) for seven days and thereafter a low sodium diet (NaCl 2 to 3 g/d) for seven days. Ouabain-sensitive 86 Rb+ influx into the red blood cells (RBC) obtained from a healthy subject, and incubated with the plasma obtained during the high sodium diet was significantly lower than that incubated with the plasma obtained during the low sodium diet (3.74 +/- 0.26 v 3.97 +/- 0.30 nmol/10(8) cells, P less than .05). The changes in mean blood pressure from the high to low sodium diet showed a significant positive correlation with the changes in the ouabain-sensitive Rb influx into RBC in the plasma from the high to low sodium diet. These results suggest that a humoral factor modifying the sodium pump might be altered by sodium balance in EH, especially in salt-sensitive hypertension

Effect of dietary sodium on the Na-K ATPase inhibitor in patients with essential hypertension

Energy Technology Data Exchange (ETDEWEB)

Ashida, T.; Kuramochi, M.; Kojima, S.; Yoshimi, H.; Kawano, Y.; Kimura, G.; Abe, H.; Imanishi, M.; Yoshida, K.; Kawamura, M. (National Cardiovascular Center, Osaka (Japan))

1989-07-01

To study the circulating humoral factor modifying transmembrane sodium transport, plasma was obtained from 12 patients with essential hypertension (EH) fed a high sodium diet (NaCl 15 to 17 g/d) for seven days and thereafter a low sodium diet (NaCl 2 to 3 g/d) for seven days. Ouabain-sensitive {sup 86}Rb+ influx into the red blood cells (RBC) obtained from a healthy subject, and incubated with the plasma obtained during the high sodium diet was significantly lower than that incubated with the plasma obtained during the low sodium diet (3.74 +/- 0.26 v 3.97 +/- 0.30 nmol/10(8) cells, P less than .05). The changes in mean blood pressure from the high to low sodium diet showed a significant positive correlation with the changes in the ouabain-sensitive Rb influx into RBC in the plasma from the high to low sodium diet. These results suggest that a humoral factor modifying the sodium pump might be altered by sodium balance in EH, especially in salt-sensitive hypertension.

Development of sodium technology

International Nuclear Information System (INIS)

Hwang, Sung Tai; Nam, H. Y.; Choi, Y. D.

2000-05-01

The objective of present study is to produce the experimental data for development and verification of computer codes for development of LMR and to develop the preliminary technologies for the future large scale verification experiments. A MHD experimental test loop has been constructed for the quantitative analysis of the effect of magnetic field on the sodium flow and experiments are carried out for three EM pumps. The previous pressure drop correlations are evaluated using the experimental data obtained from the pressure drop experiment in a 19-pin fuel assembly with wire spacer. An dimensionless variable is proposed to describe the amplitude and frequency of the fluctuation of free surface using the experimental data obtained from free surface experimental apparatus and an empirical correlation is developed using this dimensionless variable. An experimental test loop is constructed to measure the flow characteristics in IHX shell side and the local pressure drop in fuel assembly, and to test the vibration behaviour of fuel pins due to flow induced vibration. The sodium two-phase flow measuring technique using the electromagnetic flowmeter is developed and the sodium differential pressure drop measuring technique using the method of direct contact of sodium and oil is established. The work on the analysis of sodium fire characteristics and produce data for vlidation of computer code is performed. Perfect reopen time of self plugged leak path was observed to be about 130 minutes after water leak initiation. Reopen shape of a specimen appeared to be double layer of circular type, and reopen size of this specimen surface was about 2mm diameter on sodium side. In small water leakage experiments, the following correlation equation about the reopen time between sodium temperature and initial leak rate was obtained, τ c = δ·g -0.83 ·10 (3570/T Na -3.34) , in 400-500 deg C of liquid sodium atmosphere. The characteristics of pressure propagation and gas flow, and

Development of sodium technology

Energy Technology Data Exchange (ETDEWEB)

Hwang, Sung Tai; Nam, H Y; Choi, Y D [and others

2000-05-01

The objective of present study is to produce the experimental data for development and verification of computer codes for development of LMR and to develop the preliminary technologies for the future large scale verification experiments. A MHD experimental test loop has been constructed for the quantitative analysis of the effect of magnetic field on the sodium flow and experiments are carried out for three EM pumps. The previous pressure drop correlations are evaluated using the experimental data obtained from the pressure drop experiment in a 19-pin fuel assembly with wire spacer. An dimensionless variable is proposed to describe the amplitude and frequency of the fluctuation of free surface using the experimental data obtained from free surface experimental apparatus and an empirical correlation is developed using this dimensionless variable. An experimental test loop is constructed to measure the flow characteristics in IHX shell side and the local pressure drop in fuel assembly, and to test the vibration behaviour of fuel pins due to flow induced vibration. The sodium two-phase flow measuring technique using the electromagnetic flowmeter is developed and the sodium differential pressure drop measuring technique using the method of direct contact of sodium and oil is established. The work on the analysis of sodium fire characteristics and produce data for vlidation of computer code is performed. Perfect reopen time of self plugged leak path was observed to be about 130 minutes after water leak initiation. Reopen shape of a specimen appeared to be double layer of circular type, and reopen size of this specimen surface was about 2mm diameter on sodium side. In small water leakage experiments, the following correlation equation about the reopen time between sodium temperature and initial leak rate was obtained, {tau}{sub c} = {delta}{center_dot}g{sup -0.83}{center_dot}10{sup (3570/T{sub Na}-3.34)}, in 400-500 deg C of liquid sodium atmosphere. The characteristics

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

Digitalis-induced cell signaling by the sodium pump: on the relation of Src to Na(+)/K(+)-ATPase.

Science.gov (United States)

Gable, Marjorie E; Abdallah, Simon L; Najjar, Sonia M; Liu, Lijun; Askari, Amir

2014-04-18

In addition to performing its essential transport function, the sodium pump also activates multiple cell signaling pathways in response to digitalis drugs such as ouabain. Based mainly on cell-free studies with mixtures of purified Src kinase and Na(+)/K(+)-ATPase, a well-advocated hypothesis on how ouabain initiates the activation of signaling pathways is that there is a preexisting physiological complex of inactive Src bound to the α-subunit of Na(+)/K(+)-ATPase, and that ouabain binding to this subunit disrupts the bound Src and activates it. Because of the published disagreements of the results of such cell-free experiments of two other laboratories, our aim was to attempt the resolution of these discrepancies. We reexamined the effects of ouabain, vanadate, and oligomycin on mixtures of Src, Na(+)/K(+)-ATPase, Mg(2+), and ATP as specified in prior studies; and assayed for Src-418 autophosphorylation as the measure of Src activation. In contrast to the findings of the proponents of the above hypothesis, our results showed similar effects of the three inhibitors of Na(+)/K(+)-ATPase; indicating that Src activation in such experiments is primarily due to the ATP-sparing effect of the ATPase inhibitor on the mixture of two enzymes competing for ATP. We conclude that there is no solid evidence for direct molecular interaction of Src with Na(+)/K(+)-ATPase under physiological conditions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Optimization of intermediate heat exchangers for sodium cooled fast breeder reactors

International Nuclear Information System (INIS)

Barratt, R.O.; Cox, J.; Beith, R.M.V.

1978-01-01

Design evolution of the Intermediate Heat Exchanger for the U.S. Fast Breeder Programme is traced from the initial FFTF through to the Clinch River Designs and anticipated onward Commercial Plant Concepts. Supporting development work is outlined. Technical merits of certain features, such as sine wave tube banks and replaceable tube banks (in-situ), are weighed up against quantified cost advantages with simpler arrangements. Future design trends are outlined which will lead eventually to fully optimised designs. (author)

Observation of correlated anti-Stokes emissions by multiwave mixing in sodium vapor

International Nuclear Information System (INIS)

Motomura, Koji; Tsukamoto, Mayumi; Wakiyama, Akira; Harada, Ken-ichi; Mitsunaga, Masaharu

2005-01-01

We study experimentally nonlinear optical processes in which Stokes and anti-Stokes fields build up under strong, resonant, counterpropagating pump laser excitation in atomic sodium vapor. We find that, at some pump frequency, two off-axis anti-Stokes emissions propagating along reflection-symmetric directions are strongly temporally correlated, with a correlation time of 0.5 μs and a correlation range of 1 mrad. It is shown by the numerical analysis based on six-wave mixing process involving pump, Stokes, and anti-Stokes waves in the forward and the backward directions that such correlated anti-Stokes emissions are possible when the medium is opaque for the Stokes field and transparent for the anti-Stokes field. Possibilities of quantum correlation for entangled photon generation using this system are discussed

Efficacy of omeprazole/sodium bicarbonate treatment in gastroesophageal reflux disease: a systematic review.

Science.gov (United States)

Higuera-de-la-Tijera, Fátima

2018-03-14

Proton pump inhibitors are the most effective medical therapy for gastroesophageal reflux disease, but their onset of action may be slow. To assess the available literature regarding the efficacy of omeprazole/sodium bicarbonate in gastroesophageal reflux patients. A systematic review was conducted. A systematic literature search starting from 2000. Reviewed manuscripts concerning the effectiveness of omeprazole/sodium bicarbonate treatment in gastroesophageal reflux disease were reviewed and the data were extracted. Data were subsequently analyzed with descriptive statistics. This review included information of four studies. Two trials compared the efficacy of omeprazole/sodium bicarbonate versus omeprazole. One study compared the efficacy of once-daily morning or nighttime dosing. And another study compared omeprazole/sodium bicarbonate/alginate versus omeprazole. In total, there was no difference between omeprazole/sodium bicarbonate and omeprazole. However, there is a trend towards more sustained response and a greater proportion of patients with sustained total relief by 30 minutes with omeprazole/sodium bicarbonate. Omeprazole/sodium bicarbonate therapy is not more effective than omeprazole in the treatment of gastroesophageal reflux disease. However, data obtained suggest that it can have a more sustained response and sustained total relief.

One-dimensional model of inertial pumping

Science.gov (United States)

Kornilovitch, Pavel E.; Govyadinov, Alexander N.; Markel, David P.; Torniainen, Erik D.

2013-02-01

A one-dimensional model of inertial pumping is introduced and solved. The pump is driven by a high-pressure vapor bubble generated by a microheater positioned asymmetrically in a microchannel. The bubble is approximated as a short-term impulse delivered to the two fluidic columns inside the channel. Fluid dynamics is described by a Newton-like equation with a variable mass, but without the mass derivative term. Because of smaller inertia, the short column refills the channel faster and accumulates a larger mechanical momentum. After bubble collapse the total fluid momentum is nonzero, resulting in a net flow. Two different versions of the model are analyzed in detail, analytically and numerically. In the symmetrical model, the pressure at the channel-reservoir connection plane is assumed constant, whereas in the asymmetrical model it is reduced by a Bernoulli term. For low and intermediate vapor bubble pressures, both models predict the existence of an optimal microheater location. The predicted net flow in the asymmetrical model is smaller by a factor of about 2. For unphysically large vapor pressures, the asymmetrical model predicts saturation of the effect, while in the symmetrical model net flow increases indefinitely. Pumping is reduced by nonzero viscosity, but to a different degree depending on the microheater location.

Mechanical Design Features of the KALIMER-600 Sodium-Cooled Reactor

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Han; Park, Chang Gyu; Kim, Jong Bum [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2005-07-01

KALIMER-600 is a sodium cooled reactor with a fast spectrum neutron reactor core. The NSSS design has three heat transport systems of a PHTS (Primary Heat Transport System), a IHTS (Intermediate Heat Transport System) and a SGS (Steam Generation System). PHTS is a pool type and has a large amount of sodium in the pool. The mechanical design targets are maintaining the enough structural integrity for a seismic load of SSE 0.3g and the thermal and mechanical loads by the high temperature environments and an economical competitiveness when compared with other reactor types.

Mechanical Design Features of the KALIMER-600 Sodium-Cooled Reactor

International Nuclear Information System (INIS)

Lee, Jae Han; Park, Chang Gyu; Kim, Jong Bum

2005-01-01

KALIMER-600 is a sodium cooled reactor with a fast spectrum neutron reactor core. The NSSS design has three heat transport systems of a PHTS (Primary Heat Transport System), a IHTS (Intermediate Heat Transport System) and a SGS (Steam Generation System). PHTS is a pool type and has a large amount of sodium in the pool. The mechanical design targets are maintaining the enough structural integrity for a seismic load of SSE 0.3g and the thermal and mechanical loads by the high temperature environments and an economical competitiveness when compared with other reactor types

Final technical report. A sodium-cycle based organism with improved membrane resistance aimed at increasing the efficiency of energy biotransformations

International Nuclear Information System (INIS)

Lewis, Kim

2001-01-01

The aim of the project was to express in E. coli components that would allow a formation of oxidative phosphorylation based on a sodium cycle. This would improve the resistance of cells to organic solvents, detergents and other toxins. The author cloned and expressed the nqr operon FR-om H. influenzae in E. coli. Experiments with membrane vesicles indicated the presence of the functional recombinant sodium pumping NADH dehydrogenase. A gene for a hybrid E. coli/P.modestum ATPase was constructed which will enable one to co-express a sodium ATPsynthase together with a sodium NADH dehydrogenase

Structural relaxation dynamics and annealing effects of sodium silicate glass.

Science.gov (United States)

Naji, Mohamed; Piazza, Francesco; Guimbretière, Guillaume; Canizarès, Aurélien; Vaills, Yann

2013-05-09

Here we report high-precision measurements of structural relaxation dynamics in the glass transition range at the intermediate and short length scale for a strong sodium silicate glass during long annealing times. We evidence for the first time the heterogeneous dynamics at the intermediate range order by probing the acoustic longitudinal frequency in the GHz region by Brillouin light scattering spectroscopy. Or, from in-situ Raman measurements, we show that relaxation is indeed homogeneous at the interatomic length scale. Our results show that the dynamics at the intermediate range order contains two distinct relaxation time scales, a fast and a slow component, differing by about a 10-fold factor below Tg and approaching to one another past the glass transition. The slow relaxation time agrees with the shear relaxation time, proving that Si-O bond breaking constitutes the primary control of structural relaxation at the intermediate range order.

Reaction pathways of photoexcited retinal in proteorhodopsin studied by pump-dump-probe spectroscopy.

Science.gov (United States)

Rupenyan, Alisa; van Stokkum, Ivo H M; Arents, Jos C; van Grondelle, Rienk; Hellingwerf, Klaas J; Groot, Marie Louise

2009-12-17

Proteorhodopsin (pR) is a membrane-embedded proton pump from the microbial rhodopsin family. Light absorption by its retinal chromophore initiates a photocycle, driven by trans/cis isomerization on the femtosecond to picosecond time scales. Here, we report a study on the photoisomerization dynamics of the retinal chromophore of pR, using dispersed ultrafast pump-dump-probe spectroscopy. The application of a pump pulse initiates the photocycle, and with an appropriately tuned dump pulse applied at a time delay after the dump, the molecules in the initial stages of the photochemical process can be de-excited and driven back to the ground state. In this way, we were able to resolve an intermediate on the electronic ground state that represents chromophores that are unsuccessful in isomerization. In particular, the fractions of molecules that undergo slow isomerization (20 ps) have a high probability to enter this state rather than the isomerized K-state. On the ground state reaction surface, return to the stable ground state conformation via a structural or vibrational relaxation occurs in 2-3 ps. Inclusion of this intermediate in the kinetic scheme led to more consistent spectra of the retinal-excited state, and to a more accurate estimation of the quantum yield of isomerization (Phi = 0.4 at pH 6).

SNR coolant system components

International Nuclear Information System (INIS)

De Haas Van Dorsser, A.H.; Mausbeck, H.

1976-01-01

The DEBENELUX prototype fast reactor power plant SNR 300 at Kalkar has a loop-type heat transfer system similar to that of the prototype LMFBR plants in the USA and Japan. There exist three 257 MW/sub th/ primary sodium loops, each with a hot leg centrifugal pump and three 85.6 MW/sub th/ intermediate heat exchangers in parallel. From there the heat is transferred to the steam generators via three secondary sodium loops with one cold leg sodium circulating pump in each. At a nominal reactor outlet temperature of 819 0 K and a turbine inlet power of 771 MW/sub th/ super heated steam of 166 bar and 733 0 K is produced, giving rise to a plant rating of 327 MW/sub e/ gross. The primary and secondary loops are described in detail

Fire protection at the Fast Flux Test Facility (a sodium cooled test reactor)

International Nuclear Information System (INIS)

Bell, J.R.

1980-01-01

For purposes of this presentation, fire protection at the FFTF is subdivided into two catagories; protection for non-sodium areas and protection for areas containing sodium. Fire protection systems and philosophies for non-sodium areas at the FFTF are very similar to those used at conventional power plants being constructed throughout the country. They follow, essentially, the NRC rules and guidelines and ANSI 59.4 Generic Requirements for Light Water Nuclear Power Plant Fire Protection. The FFTF with its support facilities have their own water system comprised of a looped 8'' and 10'' underground distribution system, three 1500 GPM fire pumps and three ground level storage tanks totaling 736,000 gallons with 420,000 reserved for fire protection. Fire hydrants are enclosed with hose houses outfitted for use by the Emergency Response Team (ERT). Fire prevention systems for sodium areas of the FFTF are also described

Natriuretic peptides stimulate the cardiac sodium pump via NPR-C-coupled NOS activation

DEFF Research Database (Denmark)

William, M.; Hamilton, E.J.; Garcia, A.

2008-01-01

Natriuretic peptides (NPs) and their receptors (NPRs) are expressed in the heart, but their effects on myocyte function are poorly understood. Because NPRs are coupled to synthesis of cGMP, an activator of the sarcolemmal Na(+)-K(+) pump, we examined whether atrial natriuretic peptide (ANP) regul...

Sodium-23 magnetic resonance brain imaging

International Nuclear Information System (INIS)

Winkler, S.S.; Wisconsin Univ., Madison

1990-01-01

This is a review of recent work in 23 Na MR imaging. The main emphasis of recent papers has been pulse sequences that, with appropriate postprocessing, give images of the fast, slow, and intermediate components of T 2 decay. The assignment of compartmental designation to the T 2 component remains a problem except for homogeneous structures easily identifiable anatomically (ventricles, superior sagittal sinus, globe of the eye). Compartmental distribution of sodium is described. The predominance of the interstitial and plasma compartment, the invisibility of part of the intracellular sodium, and the difficulty in imaging the very fast T 2 component of visible intracellular sodium make the usual Na spin-echo image essentially an image of the interstitial and plasma space. Use of paramagnetic iron oxide coupled to dextran as a contrast medium may help to identify the plasma compartment. Because the usual Na MR images are essentially interstitial and plasma images, our own interest is in observing functional changes in these compartments. Another proposed application is the detection of the very fast T 2 component in brain tumors to aid in defining tumor grade and extent. (orig.)

Prospects for a deuterium internal target, tensor polarized by optical pumping: spin exchange

International Nuclear Information System (INIS)

Green, M.C.

1984-01-01

The prospects for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) appropriate for nuclear physics studies in medium and high energy particle storage rings are discussed. Using the technique of electron spin exchange with an optically pumped sodium (or potassium) vapor, we hope to polarize deuterium at a rate approx. 10 17 atoms/sec. Predictions for the deuterium polarization for a particular target cell design will be presented leading to the identification of the required optical pumping power and cell wall depolarization probability to attain optimum performance. The technical obstacles to be surmounted in such a target design will also be discussed

Cleaning of the equipment of residual sodium by means of water-vacuum technology

International Nuclear Information System (INIS)

Klykov, B.P.; Lednev, A.I.

1997-01-01

Results of investigation into a problem of equipment decontamination from sodium, that have been conducted in OKBM since 1960 are given. The investigations performed have shown that a water-vacuum washing process is the most optimal method for equipment decontamination from sodium residues. The essence of the method is in conduction of sodium-water reaction under reduced pressure in a leak-tight tank. Boundary conditions are selected experimentally which not allow sodium to be melted during the process, that gives possibility to control the sodium-water reaction. Continuous removal of H 2 and reaction products creates safe conditions for the process conduction. More that 20-year period of operation of a stationary water-vacuum facility and washing the electromagnetic pump for BN-350 fast nuclear reactor directly at is test rig are the best proofs of the proposed method. This method is well suitable for washing the equipment contaminated by radioactive sodium, because by-products of the process are simply utilized. The method is used in a number of Russian enterprises, and recommended for implementation at BN-350 and BN-600 reactor plants. (author)

Development of KALIMER auxiliary sodium and cover gas management system

International Nuclear Information System (INIS)

Kwon, Sang Woon; Hwang, Sung Tae

1996-11-01

The objectives of this report are to develop and to describe the auxiliary liquid metal and cover gas management systems of KALIMER. the system includes following system: (1) Auxiliary liquid metal system (2) Inert gas receiving and processing system (3) Impurity monitoring and analysis system. Auxiliary liquid metal and cover gas management system of KALIMER was developed. Functions of each systems and design basis were describes. The auxiliary liquid metal system receives, transfers, and purifies all sodium used in the plant. The system furnishes the required sodium quantity at the pressure, temperature, flow rate, and purity specified by the interfacing system. The intermediated sodium processing subsystem (ISPS) provides continuous purification of IHTS sodium, as well as performs the initial fill operation for both the IHTS and reactor vessel. The primary sodium processing subsystem provides purification (cold trapping) for sodium used in the reactor vessel. The inert gas receiving and processing (IGRP) system provides liquefied and ambient gas storage, delivers inert gases of specified composition and purity at regulated flow rates and pressures to points of usage throughout the KALIMER, and accepts the contaminated gases through its vacuum facilities for storage and transfer to the gas radwaste system. Three gases are used in the KALIMER: helium, argon, and nitrogen. 11 tabs., 12 figs. (Author)

Development of KALIMER auxiliary sodium and cover gas management system

Energy Technology Data Exchange (ETDEWEB)

Kwon, Sang Woon; Hwang, Sung Tae [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1996-11-01

The objectives of this report are to develop and to describe the auxiliary liquid metal and cover gas management systems of KALIMER. the system includes following system: (1) Auxiliary liquid metal system (2) Inert gas receiving and processing system (3) Impurity monitoring and analysis system. Auxiliary liquid metal and cover gas management system of KALIMER was developed. Functions of each systems and design basis were describes. The auxiliary liquid metal system receives, transfers, and purifies all sodium used in the plant. The system furnishes the required sodium quantity at the pressure, temperature, flow rate, and purity specified by the interfacing system. The intermediated sodium processing subsystem (ISPS) provides continuous purification of IHTS sodium, as well as performs the initial fill operation for both the IHTS and reactor vessel. The primary sodium processing subsystem provides purification (cold trapping) for sodium used in the reactor vessel. The inert gas receiving and processing (IGRP) system provides liquefied and ambient gas storage, delivers inert gases of specified composition and purity at regulated flow rates and pressures to points of usage throughout the KALIMER, and accepts the contaminated gases through its vacuum facilities for storage and transfer to the gas radwaste system. Three gases are used in the KALIMER: helium, argon, and nitrogen. 11 tabs., 12 figs. (Author).

AS160 associates with the Na+,K+-ATPase and mediates the adenosine monophosphate-stimulated protein kinase-dependent regulation of sodium pump surface expression.

Science.gov (United States)

Alves, Daiane S; Farr, Glen A; Seo-Mayer, Patricia; Caplan, Michael J

2010-12-01

The Na(+),K(+)-ATPase is the major active transport protein found in the plasma membranes of most epithelial cell types. The regulation of Na(+),K(+)-ATPase activity involves a variety of mechanisms, including regulated endocytosis and recycling. Our efforts to identify novel Na(+),K(+)-ATPase binding partners revealed a direct association between the Na(+),K(+)-ATPase and AS160, a Rab-GTPase-activating protein. In COS cells, coexpression of AS160 and Na(+),K(+)-ATPase led to the intracellular retention of the sodium pump. We find that AS160 interacts with the large cytoplasmic NP domain of the α-subunit of the Na(+),K(+)-ATPase. Inhibition of the activity of the adenosine monophosphate-stimulated protein kinase (AMPK) in Madin-Darby canine kidney cells through treatment with Compound C induces Na(+),K(+)-ATPase endocytosis. This effect of Compound C is prevented through the short hairpin RNA-mediated knockdown of AS160, demonstrating that AMPK and AS160 participate in a common pathway to modulate the cell surface expression of the Na(+),K(+)-ATPase.

Stabilized sulfur as cathodes for room temperature sodium-ion batteries.

Energy Technology Data Exchange (ETDEWEB)

Xu, Yunhua [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Liu, Yang [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies; Zhu, Yujie [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Zheng, Shiyou [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Liu, Yihang [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Luo, Chao [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Gaskell, Karen [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry; Eichhorn, Bryan [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry; Wang, Chunsheng [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering

2013-05-01

Sodium-sulfur batteries, offering high capacity and low cost, are promising alternative to lithium-ion batteries for large-scale energy storage applications. The conventional sodium-sulfur batteries, operating at a high temperature of 300–350°C in a molten state, could lead to severe safety problems. However, the room temperature sodium-sulfur batteries using common organic liuid electrolytes still face a significant challenge due to the dissolution of intermediate sodium polysulfides. For this study, we developed room temperatue sodium-sulfur batteries using a unique porous carbon/sulfur (C/S) composite cathode, which was synthesized by infusing sulfur vapor into porous carbon sphere particles at a high temperatrure of 600°C. The porous C/S composites delivered a reversible capacity of ~860 mAh/g and retained 83% after 300 cycles. The Coulombic efficiency of as high as 97% was observed over 300 cycles. The superior electrochemical performance is attrbuted to the super sulfur stability as evidenced by its lower sensitivity to probe beam irradiation in TEM, XPS and Raman charaterization and high evaperation temperature in TGA. The results make it promising for large-scale grid energy storage and electric vehicles.

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

Calculational model and code for corrosion products transfer in sodium systems

International Nuclear Information System (INIS)

Iizawa, Katsuyuki; Kikuchi, Takao; Nihei, Isao; Horie, Junnosuke

1987-01-01

The parameters to predict LMFBR radioactive CP behaviour are obtained by fitting the model to the release rates and distribution of deposits in experimental sodium loops. Analysis of the downstream effect for Co-60 deposition confirms that the mechanism controlling Co-60 transfer is diffusion through the boundary sublayer in the flowing sodium. On the other hand, analysis of Mn-54 deposition suggests that the controlling mechanism for this nuclide is probably an intermediate case between diffusion-control in the liquid and reaction-control at steel surfaces. The super-stoichiometric release of Mn-54 and the sub-stoichiometric release of Co-60 are interpreted from their model parameters as being likely related to their solubilities in sodium. The computer code developed for this model is named PSYCHE. (orig./HP)

Experimental study of R134a/R410A cascade cycle for variable refrigerant flow heat pump systems

International Nuclear Information System (INIS)

Kim, Jeong Hun; Lee, Jae Wan; Park, Warn Gyu; Choi, Hwan Jong; Lee, Sang Hun; Oh, Sai Kee

2015-01-01

Cascade cycle is widely applied to heat pumps operating at low ambient temperature to overcome problems such as low heating capacity and Coefficient of performance (COP) deterioration A number of researches have been conducted on cascade cycle heat pumps, but most of those studies were focused on system optimization to determine optimal intermediate temperature in air-to-water heat pumps. However, experimental optimization in regard to air and water heating simultaneously using a cascade cycle has been an understudied area. Therefore, we focused on experimental analysis for a cascade system with Variable refrigerant flow (VRF) heat pumps. Experiments were conducted under a variety of operating conditions, such as ambient and water inlet temperature. COP increased up to 16% when water inlet temperature decreased. COP of VRF heat pumps with cascade cycle is three-times higher compared with conventional boilers as well as 17% higher compared to single heat pumps

Natriuretic Hormones, Endogenous Ouabain, and Related Sodium Transport Inhibitors

Directory of Open Access Journals (Sweden)

John eHamlyn

2014-12-01

Full Text Available The work of deWardener and colleagues stimulated longstanding interest in natriuretic hormones (NH. In addition to the atrial peptides (APs, the circulation contains unidentified physiologically-relevant NHs. One NH is controlled by the central nervous system (CNS and likely secreted by the pituitary. Its circulating activity is modulated by salt intake and the prevailing sodium concentration of the blood and intracerebroventricular fluid, and contributes to postprandial and dehydration natriuresis. The other NH, mobilized by atrial stretch, promotes natriuresis by increasing the production of intrarenal dopamine and/or nitric oxide. Both NHs have short (<35 minutes circulating half lives, depress renotubular sodium transport, and neither requires the renal nerves. The search for NHs led to endogenous cardiotonic steroids (CTS including ouabain-, digoxin-, and bufadienolide-like materials. These CTS, given acutely in high nanomole to micromole amounts into the general or renal circulations, inhibit sodium pumps and are natriuretic. Among these CTS, only bufalin is cleared sufficiently rapidly to qualify for an NH-like role. Ouabain-like CTS are cleared slowly, and when given chronically in low daily nanomole amounts, promote sodium retention, augment arterial myogenic tone, reduce renal blood flow and glomerular filtration, suppress nitric oxide in the renal vasa recta, and increase sympathetic nerve activity and blood pressure. Moreover, lowering total body sodium raises circulating endogenous ouabain. Thus, ouabain-like CTS have physiological actions that, like aldosterone, support renal sodium retention and blood pressure. In conclusion, the mammalian circulation contains two non-AP NHs. Identification of the CNS NH should be a priority.

Synopsis on remarks on the topics of the agenda, presentated for informal discussion during the Specialists Meeting on Operational Safety of Sodium Circuits on 17 to 20 March 1971

International Nuclear Information System (INIS)

Gasselt, N.L.G. van

1971-01-01

The work done in the Sodium field by the Department of Nuclear Reactor Technology of the Central Technical Institute TNO at Apeldoorn, consists mainly of the design, construction and operation of sodium test rigs, four of which are rigs for the investigation of corrosion phenomena. Research and development on sodium pumps, electromagnetic brakes, large valves, forced circulation cold traps, vapor traps, electrical trace heating, instrumentation, impurity monitoring, in-line distillation and sodium chemistry

The mode of inhibition of the Na+-K+ pump activity in mast cells by calcium

DEFF Research Database (Denmark)

Knudsen, T; Johansen, Torben

1989-01-01

, and hence the pump activity. This hypothesis is supported by the stimulation of pump activity produced by monensin, which is not inhibited by calcium. The enhancement of pump activity after exposure of calcium-deprived cells to EGTA might be the result of a further increase in the sodium permeability......1 The inhibition by calcium of the Na(+)-K+ pump in the plasma membrane of rat peritoneal mast cells was studied in pure populations of the cells by measuring the ouabain-sensitive uptake of the radioactive potassium analogue, 86rubidium (86Rb+). 2 Exposure of the cells to calcium induced a time......- and concentration-dependent decrease in the ouabain-sensitive K+(86Rb+)-uptake of the cells without influencing the ouabain-resistant uptake. The development of the inhibition required the presence of potassium in the medium in the millimolar range (1.5-8.0 mM), and it did not occur at a concentration of potassium...

Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

Directory of Open Access Journals (Sweden)

Fic Adam

2015-03-01

Full Text Available Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle, which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle. The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

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

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

Operating experience of a sodium rig following the ingress of oil

Energy Technology Data Exchange (ETDEWEB)

Bell, A C; Mehew, R D; Robertson, C M [UKAEA, Dounreay, Thurso, Caithness, Scotland (United Kingdom)

1980-05-01

The experience of operating the Small Water Leak Rig at Dounreay in the two years following the ingress into the sodium of silicone oil from the pump is reported. The carbon penetration into the rig pipework has been monitored and has been found to agree with a diffusion model. The predictions based on this model have enabled an operating strategy to be determined to allow continued operation of the rig. (author)

Operating experience of a sodium rig following the ingress of oil

International Nuclear Information System (INIS)

Bell, A.C.; Mehew, R.D.; Robertson, C.M.

1980-01-01

The experience of operating the Small Water Leak Rig at Dounreay in the two years following the ingress into the sodium of silicone oil from the pump is reported. The carbon penetration into the rig pipework has been monitored and has been found to agree with a diffusion model. The predictions based on this model have enabled an operating strategy to be determined to allow continued operation of the rig. (author)

The report of inspection and repair technology of sodium cooled reactors

International Nuclear Information System (INIS)

Kisohara, Naoyuki; Uchita, Masato; Konomura, Mamoru

2002-12-01

considered, and short-term repair methods were investigated for secondary sodium leak from the main piping. The application and issue of the repair methods were discussed for commercialized plants. More specific repair sequence must be developed for each sodium leak location by referring to other plants' repair experience. Furthermore, the repair methods of components such as a pump must be investigated. (author)

Solubilities of sodium nitrate, sodium nitrite, and sodium aluminate in simulated nuclear waste

International Nuclear Information System (INIS)

Reynolds, D.A.; Herting, D.L.

1984-09-01

Solubilities were determined for sodium nitrate, sodium nitrite, and sodium aluminate in synthetic nuclear waste liquor. Solubilities were determined as a function of temperature and solution composition (concentrations of sodium hydroxide, sodium nitrate, sodium nitrite, and sodium aluminate). Temperature had the greatest effect on the solubilities of sodium nitrate and sodium nitrite and a somewhat lesser effect on sodium aluminate solubility. Hydroxide had a great effect on the solubilities of all three salts. Other solution components had minor effects. 2 references, 8 figures, 11 tables

Investigation of a Plugging Meter for Measuring Impurity Content in Liquid Sodium (I)

International Nuclear Information System (INIS)

Choi, Jong Hyeun; Kim, Jong Man; Choi, Byoung Hae; Jeong, Ji Young; Lee, Yong Bum

2010-01-01

In a Sodium-cooled Fast Reactor (SFR), liquid sodium is subject to the formation of impurities by its high chemical reactivity with so many elements and common compounds used in nuclear reactor construction materials. The impurities are mainly in the form of hydrides, oxides, metallic compounds, metallic and carbon particles, which originate primarily from steam generator corrosion, moisture from system component surface, and leakage of air into the system. These are finally deposited in the form of the crystallization of sodium hydride (NaH) or sodium oxide (Na 2 O) at the cold points of the circuit, which may lead to the clogging of the narrowed sections or may damage the pump. Therefore, the sodium must be purified and analyzed in order to prevent from the detrimental influence. The analysis of hydrogen and oxygen is very important. There are many chemical methods for analyzing the impurities, but these methods are time-consuming, troublesome and contamination of samples from air and containers, that is the reason why the countries develop the instruments of impurity on-line measurement. The plugging meter is one of the most important on-line measuring instruments and it is a reliable instrument which has been widely used on sodium loops

PIV Investigations of the Flow Field in the Volute of a Rotary Blood Pump

Science.gov (United States)

Sankovic, John M.; Kadambi, Jaikrishnan R.; Smith, William A.; Wernet, Mark P.

2004-01-01

A full-size acrylic model of a rotary blood pump was developed in order to utilize Particle Image Velocimetry (PIV) to make measurements of the fluid velocities and turbulent stresses throughout the device. The development of an understanding of the hemodynamics within the blood pump is critical to the development and validation of computational models. A blood analog solution, consisting of sodium iodide solution and glycerin, was developed to match physiological kinematic viscosity. The refractive indices of the fluid, the pump casing, and the impeller were matched to facilitate the use of PIV to make velocity measurements. Velocity measurements made in the volute exit/diffuser region are presented for pumps speeds of 3000-3850 rpm. At each speed data were obtained at a physiological pressure of 12 kPa and at a maximum flow condition. Four hundred data pairs were used for each resultant mean velocity vector value, representing greater than an order of magnitude more data pairs than reported previously in the literature on similar devices and resulting in velocity uncertainty levels of approximately 22.9%.

Cavitation experiments at butterfly valves in water and in sodium at 850K

International Nuclear Information System (INIS)

Mendte, K.; Klemm, J.

1976-01-01

Throttling valves fabricated by Gebrueder Adams, Bochum will be installed in the SNR-300 plant, serving as flow control devices during postscram operation. Valves of the same type were used in the pump test facility at INTERATOM (APB) to throttle down the sodium pump head. This test loop was to demonstrate at the same time that the prototype SNR valves could withstand the design conditions (flow and temperature) during endurance tests. To optimize the pump test facility design, a 350mm diameter valve was tested in water under cavitational conditions. With the aid of calculational method described herein, the hydraulic kinetic relationships of the throttled flow could predict the influences leading to cavitation. The results of the calculational model showed close agreement with that, actually incurred during visual observations. Valves of the same type and in 350mm as well as in 600mm diameter sizes were again cavitation tested in sodium. During this test, in addition to the hydraulic data, noise measurements were taken using accelerometers. Concerning such tests, the following inherent difficulties are to be noted: a) The noise measurements would register influences of general entrained bubbles (gas and vapor bubbles) causing increased attenuation of the noise in the medium of transmission. Therefore, it is mandatory that the loop be carefully degassed to enable measurement of the cavitational bubbles. b) The primary function of these valves in the test loop APB is to dissipate the pressure head of the pump being tested. Through energy dissipation across the valves, they become strong sources of noise generation, in broad-band frequency levels at these locations up to a factor 50 larger than those at the pump. The cavitation dependent vaporizing noise, developed by incipient cavitation, was, inspite of background noise, measurable. Similar to that for the water test runs, incipient cavitation was detected at the valves when the corresponding sigma worths were

Transmural gradients in Na/K pump activity and [Na+]I in canine ventricle.

Science.gov (United States)

Gao, J; Wang, W; Cohen, I S; Mathias, R T

2005-09-01

There are well-documented differences in ion channel activity and action potential shape between epicardial (EPI), midmyocardial (MID), and endocardial (ENDO) ventricular myocytes. The purpose of this study was to determine if differences exist in Na/K pump activity. The whole cell patch-clamp was used to measure Na/K pump current (I(P)) and inward background Na(+)-current (I(inb)) in cells isolated from canine left ventricle. All currents were normalized to membrane capacitance. I(P) was measured as the current blocked by a saturating concentration of dihydro-ouabain. [Na(+)](i) was measured using SBFI-AM. I(P)(ENDO) (0.34 +/- 0.04 pA/pF, n = 17) was smaller than I(P)(EPI) (0.68 +/- 0.09 pA/pF, n = 38); the ratio was 0.50 with I(P)(MID) being intermediate (0.53 +/- 0.13 pA/pF, n = 19). The dependence of I(P) on [Na(+)](i) or voltage was essentially identical in EPI and ENDO (half-maximal activation at 9-10 mM [Na(+)](i) or approximately -90 mV). Increasing [K(+)](o) from 5.4 to 15 mM caused both I(P)(ENDO) and I(P)(EPI) to increase, but the ratio remained approximately 0.5. I(inb) in EPI and ENDO were nearly identical ( approximately 0.6 pA/pF). Physiological [Na(+)](i) was lower in EPI (7 +/- 2 mM, n = 31) than ENDO (12 +/- 3 mM, n = 29), with MID being intermediate (9 +/- 3 mM, n = 22). When cells were paced at 2 Hz, [Na(+)](i) increased but the differences persisted (ENDO 14 +/- 3 mM, n = 10; EPI 9 +/- 2 mM, n = 10; and MID intermediate, 11 +/- 2 mM, n = 9). Based on these results, the larger I(P) in EPI appears to reflect a higher maximum turnover rate, which implies either a larger number of active pumps or a higher turnover rate per pump protein. The transmural gradient in [Na(+)](i) means physiological I(P) is approximately uniform across the ventricular wall, whereas transporters that utilize the transmembrane electrochemical gradient for Na(+), such as Na/Ca exchange, have a larger driving force in EPI than ENDO.

Study of the characteristics of water into sodium leak acoustic noise in LMR steam generator

International Nuclear Information System (INIS)

Kim, Tae Joon; Jeong, Kyung Chai; Jeong, Ji Young; Hur, Seop; Nam, Ho Yun

2005-01-01

A successful time for detecting a water/steam leak into sodium in the LMR SG (steam generator) at an early phase of a leak origin depends on the fast response and sensitivity of a leak detection system. It is considered, that the acoustic system is intended for a fast detecting of a water/steam into sodium leak of an intermediate flow rate, 1∼10 g/s. This intention of an acoustic system is stipulated by a key impossibility of a fast detecting of an intermediate leak by the present nominal systems on measuring the hydrogen in the sodium and in the cover gas concentration generated at a leak. During the self-wastage of a water/steam into sodium leak in a particular instant, it is usual in 30∼40 minutes from the moment of a leak origin, there is a modification of a leak flow out regime from bubble regime to the steam jet outflow. This evolution occurs as a jump function of the self-wastage of a leak and is escorted by an increase of a leak noise power and qualitative change of a leak noise spectrum. Subject of this study is by means of two experiments, one is an acoustic leak noise analysis of the water into sodium leak results in no damage to the LMR SG tube bundle, and another is for prediction of the frequency band under a high outflow leak condition. We experimented with the Argon gas injection considered with the phenomena of secondary leaks in real

Short-term memory of motor network performance via activity-dependent potentiation of Na+/K+ pump function.

Science.gov (United States)

Zhang, Hong-Yan; Sillar, Keith T

2012-03-20

Brain networks memorize previous performance to adjust their output in light of past experience. These activity-dependent modifications generally result from changes in synaptic strengths or ionic conductances, and ion pumps have only rarely been demonstrated to play a dynamic role. Locomotor behavior is produced by central pattern generator (CPG) networks and modified by sensory and descending signals to allow for changes in movement frequency, intensity, and duration, but whether or how the CPG networks recall recent activity is largely unknown. In Xenopus frog tadpoles, swim bout duration correlates linearly with interswim interval, suggesting that the locomotor network retains a short-term memory of previous output. We discovered an ultraslow, minute-long afterhyperpolarization (usAHP) in network neurons following locomotor episodes. The usAHP is mediated by an activity- and sodium spike-dependent enhancement of electrogenic Na(+)/K(+) pump function. By integrating spike frequency over time and linking the membrane potential of spinal neurons to network performance, the usAHP plays a dynamic role in short-term motor memory. Because Na(+)/K(+) pumps are ubiquitously expressed in neurons of all animals and because sodium spikes inevitably accompany network activity, the usAHP may represent a phylogenetically conserved but largely overlooked mechanism for short-term memory of neural network function. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

International Nuclear Information System (INIS)

Sarin, Badal; Chugh, Pradeep Kumar; Kaushal, Dinesh; Soni, Nakse Lal; Sawroop, Kishan; Mondal, Anupam; Bhatnagar, Aseem

2004-01-01

It is well known that sodium bicarbonate in pharmacological doses induces transient alkalosis, causing intracellular transport of serum potassium. The aims of this study were (a) to investigate whether, in humans, myocardial thallium-201 uptake can be augmented by pretreatment with a single bolus of sodium bicarbonate at a pharmacological dose, (b) to verify general safety aspects of the intervention and (c) to evaluate the clinical implications of augmentation of 201 Tl uptake, if any. Routine exercise myocardial scintigraphy was performed twice in eight adult volunteers (five normal and three abnormal), once without intervention and the second time (within a week) following intravenous administration of sodium bicarbonate (88 mEq in 50 ml) as a slow bolus 1 h prior to the injection of 201 Tl. Conventional myocardial thallium study was compared with sodium bicarbonate interventional myocardial scintigraphy with respect to myocardial uptake (counts per minute per mCi injected dose), washout patterns in normal and abnormal myocardial segments, and overall clinical interpretation based on planar and single-photon emission tomographic (SPET) images. All patients remained asymptomatic after the intervention. A mean increase of 53% in myocardial uptake of thallium was noted in post-exercise acquisitions after the intervention, confirming uptake of the tracer via the potassium-hydrogen pump and its augmentation by transient alkalosis. The washout pattern remained unchanged. The visual quality of planar and SPET images improved significantly after the intervention. Out of the five abnormal myocardial segments identified in three cases, four showed significant filling-in after the intervention, causing the diagnosis to be upgraded from ''partial scar'' to ''ischaemia'', or from ''ischaemia'' to ''normal''. The overall scan impression changed in two out of three such cases. Sodium bicarbonate augmentation may have significant implications for stress-thallium scintigraphy

Three-dimensional finite-element analysis of the cellular convection phenomena in the Clinch River Breeder Reactor Plant prototype pump

International Nuclear Information System (INIS)

Silver, A.H.; Lee, J.Y.

1983-01-01

Cellular convection was studied rigorously during the development of the Clinch River Breeder Reactor Plant (CRBRP) Program Pumps. This paper presents the development of a three-dimensional finite-element heat transfer model which accounts for the cellular convection phenomena. A buoyancy driven cellular convection flow pattern is introduced in the annulus region between the upper inner structure and the pump tank. Steady-state thermal data were obtained for several test conditions for argon gas pressures up to 93 psig (741 kPa) and sodium operating temperatures to 1000 0 F (811 0 K). Test temperature distributions on the pump tank and inner structure were correlated with numerical results and excellent agreement was obtained

Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

International Nuclear Information System (INIS)

Green, M.C.

1984-01-01

A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target

Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

International Nuclear Information System (INIS)

Green, M.C.

1984-05-01

A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target. 15 references, 10 figures

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

Nanoparticle-mediated nonclassical crystal growth of sodium fluorosilicate nanowires and nanoplates

Directory of Open Access Journals (Sweden)

Hongxia Li

2011-12-01

Full Text Available We observed nonclassical crystal growth of the sodium fluorosilicate nanowires, nanoplates, and hierarchical structures through self-assembly and aggregation of primary intermediate nanoparticles. Unlike traditional ion-by-ion crystallization, the primary nanoparticles formed first and their subsequent self-assembly, fusion, and crystallization generated various final crystals. These findings offer direct evidences for the aggregation-based crystallization mechanism.

On the Importance of Purification of Sodium Polystyrene Sulfonate

OpenAIRE

Sen, Akhil K.; Roy, Sandip; Juvekar, Vinay A.

2012-01-01

Ion exchange is commonly employed for purification of sodium polystyrene sulfonate (NaPSS), a molecule widely used as a model polyelectrolyte. However, the present work demonstrates that the ion exchange process itself may introduce some extraneous species into NaPSS samples by two possible mechanisms: (i) chemical transformation of polystyrene sulfonic acid (HPSS), a relatively unstable intermediate formed during ion exchange and (ii) release of small amount of “condensed” acid from cationic...

Laser-induced nuclear orientation and gamma anisotropy in sodium

International Nuclear Information System (INIS)

Pappas, P.G.

1980-12-01

The use of laser optical pumping to induce nuclear orientation in several isotopes and one isomer of atomic sodium vapor is described. Essentially complete nuclear polarization, P > 90%, has been achieved in stable 23 Na when pumping with modest laser intensities (I approx. = 10 mW/cm 2 ). The volume of the sample cell was approximately 10 cc, and was filled with a sodium density of about 10'' atoms/cc. Complete coverage of the Doppler distribution was accomplished with the use of trace amounts (less than or equal to 1 torr) of argon buffer gas to induce velocity changing collisions. A theoretical model which accurately predicts the amount of polarization is developed. The orientation of nuclei which are unstable to gamma decay can manifest itself in anisotropic gamma ray emission. This anisotropy can be used to measure isotope and isomer shifts, from which nuclear properties can be derived. Gamma anisotropy was observed in two systems, 22 Na and /sup 24m/Na. From the observed anisotropy in /sup 24m/Na, a negative sign for the g factor is determined. Values are derived for the magnetic moment, μ = 2.56 +- 0.64 nm, and the isomer shift, deltaν/sub 24m/ = 288 +- 191 MHz (D1 line). A model is described which relates various laser and fubber gas parameters to the observed gamma anisotropy lineshape. This model facilitates the extraction of physical parameters from knowledge of the laser frequency at which the anisotropy is a maximum

Quantitative determination of a hydrogen impurity in a sodium coolant by hydride thermal dissociation

Science.gov (United States)

Ivanovskiy, M. N.; Pavlova, G. D.; Shmatko, B. A.; Milovidova, A. V.; Konovalov, E. YE.; Arnoldov, M. N.; Pleshivtsev, A. D.

1988-01-01

A molten sodium coolant containing hydrogen was heated in a vacuum at 450 C, and the gases generated pumped through a liquid nitrogen trap, and the H2 was then oxidized on a copper oxide substrate heated to 400 C. The accuracy of the method is 1.5 percent and the sensitivity is 1x10 to the -5 wt percent hydrogen.

MK-III function tests in JOYO. Primary main cooling pump

International Nuclear Information System (INIS)

Isozaki, Kazunori; Saito, Takakazu; Sumino, Kouzo; Karube, Kouji; Terano, Toshihiro; Sakaba, Hideo; Nakai, Satoru

2004-06-01

MK-III function test (SKS-1) that was carried out from October 17, 2001 through October 23, 2001 using MK-III transition core configuration and MK-III function tests (SKS-2) was carried out from January 27, 2003 through February 13, 2003 using MK-III core configuration. The major function tests results of primary cooling system were shown as follows; (1) The stability of the primary main pump flow control system was confirmed on both CAS (cascade) mode and Man (manual) mode. Also no divergence of flow and revolution of the pump were observed at step flow change disturbance. (2) The main motor was shifted to run-back flow control operation in about 54 seconds after scram. The flow rate and pump revolution at run-back operation of A and B cooling system were 167 m 3 /h and 117 rpm, 185m 3 /h and 118 rpm respectively. The pump revolution was within the design target revolution 122 rpm ± 8 rpm and the flow was over the 10% of the rated flow. (3) The pony motor was engaged in operation in about 39 seconds after the primary main pump trip. The flow rate and pump revolution at the pony motor operation of A and B cooling system were 180 m 3 /h and 124 rpm, 190 m 3 /h and 123 rpm respectively. These values were satisfied the design low limit of 93 rpm and 10% of the rated flow. (4) Free flow coast down time constant was longer than 10 seconds that was design shortest time at both the primary pump trip and run-back operation. (5) Pump over flow column sodium levels of both A and B cooling system at rated operating condition were NL-1550 mm and, NL-1468 mm respectively and were lower than NL-1581 mm of the design value. This result shows the new IHX pressure loss estimation was conservative. (6) It was confirmed that the primary main pump could operate with out scram for up to 0.6 seconds of external power supply loss. (author)

Indigenous development of 20 Cu. M/hr flat linear induction pump (Paper No. 047)

Energy Technology Data Exchange (ETDEWEB)

Prabhakar, R; Prakash, V; Sundarasekaran, S

1987-01-01

A distinctive physical property of sodium metal which is used as a coolant in fast reactors, is its high electrical conductivity. This together with its ability to wet stainless steel permits fluid pumping techniques using electromagnetic devices. Electromagnetic pumps are analogous to the electric motor, in which a force is produced by the interaction of magnetic field and current flowing in a conductor. Flat linear induction pump (FLIP) whose operating principle is similar to that of an induction motor is one of the types of electromagnetic pumps in wide use in auxilary circuits of fast reactors. As part of efforts to develop fast reactor components indigenously, work on the design and construction of a prototype FLIP rated for 20Cu.M/hr and 5Kg/sq.cm at 550degC was initiated. Under Board of Research in Nuclear Sciences scheme, the design was carried out by the Electrical Engineering Department of IIT, Madras. Pump was constructed at Engineering Development Division, Indira Gandhi Centre for Atomic Research, Kalpakkam. This paper presents in detail the work carried out for the fabrication of flow channel and for the stator assembly. Results obtained from dry electrical tests are also reported. Appendix summarises the design data. (author).

Dialysate sodium and sodium gradient in maintenance hemodialysis: a neglected sodium restriction approach?

OpenAIRE

Munoz Mendoza, Jair; Sun, Sumi; Chertow, Glenn M.; Moran, John; Doss, Sheila; Schiller, Brigitte

2011-01-01

Background. A higher sodium gradient (dialysate sodium minus pre-dialysis plasma sodium) during hemodialysis (HD) has been associated with sodium loading; however, its role is not well studied. We hypothesized that a sodium dialysate prescription resulting in a higher sodium gradient is associated with increases in interdialytic weight gain (IDWG), blood pressure (BP) and thirst.

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

Testing of Local Velocity Transducer Used at Sodium Thermal Hydraulic Test Facilities

International Nuclear Information System (INIS)

Kim, Tae Joon; Eoh, Jae Hyuk; Hwang, In Koo; Jeong, Ji Young; Kim, Jong Man; Lee, Yong Bum; Kim, Yeong Il

2012-01-01

KAERI (Korea Atomic Energy Research Institute) will perform a test for a thermal hydraulic simulation with STELLA-1 for a Component Performance Test Sodium Loop in the year 2012, and subsequently it will construct for STELLA-2 for a Sodium Thermalhydraulic Experimental Facility in the year 2016. The STELLA-2 consists of a scaled reactor vessel with a core of electric heaters, four IHXs, two PHTS pumps, two DHXs, and two AHXs. In STELLA-2, several kinds of flow measurements exists. In this paper, the local velocity transducer as a prototype tested in IPPE (in Russia), was manufactured as a prototype by a shop in KAERI. This local velocity transducer will be used to measure the flow rate in a pool

Intercalation and Exfoliation of Kaolinite with Sodium Dodecyl Sulfate

Directory of Open Access Journals (Sweden)

Xiaochao Zuo

2018-03-01

Full Text Available Kaolinite (Kaol was intercalated with dimethyl sulfoxide (DMSO and subsequently methanol (MeOH to prepare intercalation compounds Kaol-DMSO and Kaol-MeOH. Kaol-MeOH was used as an intermediate to synthesize Kaol-sodium dodecyl sulfate (SDS intercalation compound (Kaol-SDS via displacement reaction. The ultrasonic exfoliation of Kaol-SDS produced a resultant Kaol-SDS-U. The samples were characterized by X-ray diffraction (XRD, Fourier transformation infrared spectroscopy (FTIR, thermal analysis, scanning electronic microscopy (SEM, transmission electron microscopy (TEM and particle size analysis. The results revealed that the intercalation of sodium dodecyl sulfate into kaolinite layers caused an obvious increase of the basal spacing from 0.72–4.21 nm. The dehydroxylation temperature of Kaol-SDS was obviously lower than that of original kaolinite. During the intercalation process of sodium dodecyl sulfate, a few kaolinite layers were exfoliated and curled up from the edges of the kaolinite sheets. After sonication treatment, the kaolinite layers were further transformed into nanoscrolls, and the exfoliated resultant Kaol-SDS-U possessed a smaller particle size close to nanoscale.

Protonation of key acidic residues is critical for the K⁺-selectivity of the Na/K pump.

Science.gov (United States)

Yu, Haibo; Ratheal, Ian M; Artigas, Pablo; Roux, Benoît

2011-09-11

The sodium-potassium (Na/K) pump is a P-type ATPase that generates Na(+) and K(+) concentration gradients across the cell membrane. For each hydrolyzed ATP molecule, the pump extrudes three Na(+) and imports two K(+) by alternating between outward- and inward-facing conformations that preferentially bind K(+) or Na(+), respectively. Remarkably, the selective K(+) and Na(+) binding sites share several residues, and how the pump is able to achieve the selectivity required for the functional cycle is unclear. Here, free energy-perturbation molecular dynamics (FEP/MD) simulations based on the crystal structures of the Na/K pump in a K(+)-loaded state (E2·P(i)) reveal that protonation of the high-field acidic side chains involved in the binding sites is crucial to achieving the proper K(+) selectivity. This prediction is tested with electrophysiological experiments showing that the selectivity of the E2P state for K(+) over Na(+) is affected by extracellular pH.

Innovating analytical spectroscopies for the improvement of liquid sodium cooled fast neutron reactors safety

International Nuclear Information System (INIS)

Maury, C.

2012-01-01

In the context of the project of sodium fast reactor ASTRID, CEA is currently developing new analytical techniques to monitor the chemical purity of liquid sodium. Indeed, incidental situations occurring in the reactor, such as fuel clad failures, leakages in the steam generator or in the coolant pumps, and accelerated corrosion, might release several elements in the sodium. Analytical techniques based on laser ablation and emission spectroscopy are well suited for this application. They do not require any sample preparation, and can perform direct on-line analysis. Amongst them, Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation coupled to Laser-Induced Fluorescence (LA-LIF) have been selected for this study. The objective of this work was to characterize the sensitivity of those two techniques for the detection of impurities in liquid sodium. Their limits of detection were calculated for model analytes using calibration lines. Then results were theoretically extrapolated to other analytes of interest. This study shows the feasibility of the detection of steel corrosion products in liquid sodium. However, the LIBS technique is more robust and easier to implement, and would therefore be more suited to nuclear conditions. (author) [fr

The reaction between barium and nitrogen in liquid sodium: resistivity studies

International Nuclear Information System (INIS)

Addison, C.C.; Creffield, G.K.; Hubberstey, P.; Pulham, R.J.

1976-01-01

The reaction of nitrogen with solutions of barium (between 0.34 and 6.89 mol % Ba) in liquid sodium at 573 K has been followed by changes in the electrical resistivity of the liquid. The capillary method has been employed, continuous sampling during reaction being achieved by electromagnetic pumping. The initial solution of nitrogen in the metal, followed by precipitation of barium and nitrogen from sodium as the nitride Ba 2 N, are reflected in the resistivity changes. The solubility of nitrogen in the alloy is a linear function of the barium concentration: S(mol % N) = x/4 (0 <= x <= 6.89 mol % Ba). This and the decrease in resistivity which invariably occurs during the solution process, provides additional information on the nature of solvation of nitrogen in solution in the liquid metal. (author)

Incoherent manipulation of the photoactive yellow protein photocycle with dispersed pump-dump-probe spectroscopy.

Science.gov (United States)

Larsen, Delmar S; van Stokkum, Ivo H M; Vengris, Mikas; van Der Horst, Michael A; de Weerd, Frank L; Hellingwerf, Klaas J; van Grondelle, Rienk

2004-09-01

Photoactive yellow protein is the protein responsible for initiating the "blue-light vision" of Halorhodospira halophila. The dynamical processes responsible for triggering the photoactive yellow protein photocycle have been disentangled with the use of a novel application of dispersed ultrafast pump-dump-probe spectroscopy, where the photocycle can be started and interrupted with appropriately tuned and timed laser pulses. This "incoherent" manipulation of the photocycle allows for the detailed spectroscopic investigation of the underlying photocycle dynamics and the construction of a fully self-consistent dynamical model. This model requires three kinetically distinct excited-state intermediates, two (ground-state) photocycle intermediates, I(0) and pR, and a ground-state intermediate through which the protein, after unsuccessful attempts at initiating the photocycle, returns to the equilibrium ground state. Also observed is a previously unknown two-photon ionization channel that generates a radical and an ejected electron into the protein environment. This second excitation pathway evolves simultaneously with the pathway containing the one-photon photocycle intermediates.

Cation depletion by the sodium pump in red cells with pathologic cation leaks. Sickle cells and xerocytes.

OpenAIRE

Joiner, C H; Platt, O S; Lux, S E

1986-01-01

The mechanism by which sickle cells and xerocytic red cells become depleted of cations in vivo has not been identified previously. Both types of cells exhibit elevated permeabilities to sodium and potassium, in the case of sickle cells, when deoxygenated. The ouabain-insensitive fluxes of sodium and potassium were equivalent, however, in both cell types under these conditions. When incubated 18 hours in vitro, sickle cells lost cations but only when deoxygenated. This cation depletion was blo...

Reaction between barium and nitrogen in liquid sodium

International Nuclear Information System (INIS)

Addison, C.C.; Pulham, R.J.; Trevillion, E.A.

1975-01-01

Nitrogen in increasing amounts has been added to separate solutions of barium in sodium of constant composition (ca.4.40 mol % Ba) at 300 0 C. After rendering each mixture homogenous using an electromagnetic pump, filtration, and nitrogen analysis, all the N 2 added has been found in solution up to a solution composition approximating to Ba 4 N (i.e. 1.1 mol % N) beyond which the quantity of dissolved N 2 decreases progressively due to precipitation of the nitride Ba 2 N. The solubilization is interpreted in terms of strong preferential solvation of the nitride ion by barium cations. (author)

Dismantling of the 50 MW steam generator test facility

International Nuclear Information System (INIS)

Nakai, S.; Onojima, T.; Yamamoto, S.; Akai, M.; Isozaki, T.; Gunji, M.; Yatabe, T.

1997-01-01

We have been dismantling the 50MW Steam Generator Test Facility (50MWSGTF). The objectives of the dismantling are reuse of sodium components to a planned large scale thermal hydraulics sodium test facility and the material examination of component that have been operated for long time in sodium. The facility consisted of primary sodium loop with sodium heater by gas burner as heat source instead of reactor, secondary sodium loop with auxiliary cooling system (ACS) and water/steam system with steam temperature and pressure reducer instead of turbine. It simulated the 1 loop of the Monju cooling system. The rated power of the facility was 50MWt and it was about 1/5 of the Monju power plant. Several sodium removal methods are applied. As for the components to be dismantled such as piping, intermediate heat exchanger (IHX), air cooled heat exchangers (AC), sodium is removed by steam with nitrogen gas in the air or sodium is burned in the air. As for steam generators which material tests are planned, sodium is removed by steam injection with nitrogen gas to the steam generator. The steam generator vessel is filled with nitrogen and no air in the steam generator during sodium removal. As for sodium pumps, pump internal structure is pulled out from the casing and installed into the tank. After the installation, sodium is removed by the same method of steam generator. As for relatively small reuse components such as sodium valves, electromagnet flow meters (EMFs) etc., sodium is removed by alcohol process. (author)

Inadvertent pump start with gas expansion modules

International Nuclear Information System (INIS)

Campbell, L.R.; Harris, R.A.; Heard, F.J.; Dautel, W.A.

1992-01-01

Previous testing demonstrated the effectiveness of gas expansion modules (GEMs) in mitigating the consequences of a loss-of-flow-without-scram transient in Fast Flux Test Facility (FFTF)-sized sodium cooled cores. As a result, GEMs have been included in the advance liquid-metal reactor (PRISM) design project sponsored by the US Department of Energy. The PRISM design is under review at the US Nuclear Regulatory Commission for licensability. In the unlikely event that the reactor does not scram during a loss of low, the GEMs quickly insert sufficient negative reactivity to limit fuel and cladding temperatures to acceptable values. This is the positive benefit of the GEMs; however, the reverse situation must be considered. A primary pump could be inadvertently started from near-critical conditions resulting in a positive reactivity insertion and a power transient. One mitigating aspect of this event is that as the reactivity associated with the GEMs is inserted, the increasing flow increases core cooling. A test was conducted in the FFTF to demonstrate that the GEM and feedback reactivity are well predicted following pump start, and the reactivity transient is benign

Test results of sodium-water reaction testing in near prototypical LMR steam generator

International Nuclear Information System (INIS)

Boardman, C.E.; Hui, M.; Neely, H.H.

1990-01-01

An extensive test program has been performed in the United States to investigate the effects of large sodium-water reaction events in LMFBR steam generators. Tests were conducted in the Large Leak Test Rig (LLTR) located at the Energy Technology Engineering Center (ETEC). The program was divided into two phases, Series I and Series II, for the purpose of satisfying near-term and long-term needs. Series II was further subdivided into large and intermediate leak tests. This paper will emphasize the Series II intermediate leak tests and resulting conclusions for steam generator design and operation. 11 figs, 2 tabs

alpha-Adducin mutations increase Na/K pump activity in renal cells by affecting constitutive endocytosis: implications for tubular Na reabsorption.

Science.gov (United States)

Torielli, Lucia; Tivodar, Simona; Montella, Rosa Chiara; Iacone, Roberto; Padoani, Gloria; Tarsini, Paolo; Russo, Ornella; Sarnataro, Daniela; Strazzullo, Pasquale; Ferrari, Patrizia; Bianchi, Giuseppe; Zurzolo, Chiara

2008-08-01

Genetic variation in alpha-adducin cytoskeletal protein is implicated in the polymerization and bundling of actin and alteration of the Na/K pump, resulting in abnormal renal sodium transport and hypertension in Milan hypertensive rats and humans. To investigate the molecular involvement of alpha-adducin in controlling Na/K pump activity, wild-type or mutated rat and human alpha-adducin forms were, respectively, transfected into several renal cell lines. Through multiple experimental approaches (microscopy, enzymatic assays, coimmunoprecipitation), we showed that rat and human mutated forms increased Na/K pump activity and the number of pump units; moreover, both variants coimmunoprecipitate with Na/K pump. The increased Na/K pump activity was not due to changes in its basolateral localization, but to an alteration of Na/K pump residential time on the plasma membrane. Indeed, both rat and human mutated variants reduced constitutive Na/K pump endocytosis and similarly affected transferrin receptor trafficking and fluid-phase endocytosis. In fact, alpha-adducin was detected in clathrin-coated vesicles and coimmunoprecipitated with clathrin. These results indicate that adducin, besides its modulatory effects on actin cytoskeleton dynamics, might play a direct role in clathrin-dependent endocytosis. The constitutive reduction of the Na/K pump endocytic rate induced by mutated adducin variants may be relevant in Na-dependent hypertension.

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

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.

Sodium-water reaction test facility (SWAT-3)

International Nuclear Information System (INIS)

Shimazu, Hisashi; Ukechi, Kazutoshi; Sasakura, Kazutake; Kusunoki, Junichi

1976-01-01

In the development of the liquid metal cooled fast breeder reactor (LMFBR), the steam generator (SG) is considered one of the most important components. The Power Reactor and Nuclear Fuel Development Corporation (PNC) is now promoting the research and development of the SG system used with the prototype fast breeder reactor ''Monju''. In this research, the phenomena of the sodium-water reaction in the SG are the key which must be investigated for the solution of problems. The test facility (SWAT-3) simulating Monju's SG on the scale of 1/2.5 was designed, fabricated and installed by IHI at Oarai Engineering Center of PNC, its pre-operation being accomplished in February 1975. The purpose of SWAT-3 is summarized as follows: (1) To perform an overall test on the safety of Monju's SG and intermediate heat transport system under the design condition against sodium-water reaction accidents. (2) To investigate the damage of the SG structure caused by the sodium-water reaction, and the possibility of repair and recovery operations. The first test was accomplished successfully on June 9, 1975. As a result of the test, the fundamental function of this test facility was proven to be satisfactory as expected. (auth.)

Hydrogen-bonded intermediates and transition states during spontaneous and acid-catalyzed hydrolysis of the carcinogen (+)-anti-BPDE.

Science.gov (United States)

Palenik, Mark C; Rodriguez, Jorge H

2014-07-07

Understanding mechanisms of (+)-anti-BPDE detoxification is crucial for combating its mutagenic and potent carcinogenic action. However, energetic-structural correlations of reaction intermediates and transition states during detoxification via hydrolysis are poorly understood. To gain mechanistic insight we have computationally characterized intermediate and transition species associated with spontaneous and general-acid catalyzed hydrolysis of (+)-anti-BPDE. We studied the role of cacodylic acid as a proton donor in the rate limiting step. The computed activation energy (ΔG‡) is in agreement with the experimental value for hydrolysis in a sodium cacodylate buffer. Both types of, spontaneous and acid catalyzed, BPDE hydrolysis can proceed through low-entropy hydrogen bonded intermediates prior to formation of transition states whose energies determine reaction activation barriers and rates.

Sodium pump activity and calcium relaxation in vascular smooth muscle of deoxycorticosterone acetate-salt rats

International Nuclear Information System (INIS)

Soltis, E.E.; Field, F.P.

1986-01-01

The Na + -K + pump activity was determined in femoral arterial smooth muscle from deoxycorticosterone acetate (DOCA)-salt hypertensive rats using potassium relaxation and ouabain-sensitive 86 Rb uptake as indices. The membrane-stabilizing effect of calcium and its relation to Na + -K + pump activity also were examined. Femoral arteries from DOCA-salt rats exhibited a greater relaxation in response to potassium addition after contraction with norepinephrine in a low potassium (0.6 mM) Krebs solution. The concentration of potassium required to produce a 50% relaxation was significantly less in DOCA-salt rats. Ouabain-sensitive 86 Rb uptake was significantly greater at 3, 10, and 20 minutes of 86 Rb incubation in femoral arteries from DOCA-salt rats. Linear regression analysis revealed a significant correlation between the uptake of 86 Rb and time of incubation in both control and DOCA-salt rats. A significant difference in the slopes of the regression lines showed that the rate of uptake was greater in DOCA-salt rats. No difference was observed in ouabain-insensitive 86 Rb uptake. A dose-dependent relaxation in response to increasing concentrations of calcium following contraction to norepinephrine was observed in femoral arteries from control and DOCA-salt rats. The relaxation was directly dependent on the level of extracellular potassium and was blocked by ouabain. Femoral arteries from DOCA-salt rats relaxed to a significantly greater extent in response to calcium at each level of potassium when compared with controls. These results provide further evidence for an increase in Na + -K + pump activity in vascular smooth muscle from DOCA-salt hypertensive rats

Chemical sensors for monitoring non-metallic impurities in liquid sodium coolant

International Nuclear Information System (INIS)

Ganesan, Rajesh; Jayaraman, V.; Rajan Babu, S.; Sridharan, R.; Gnanasekaran, T.

2011-01-01

Liquid sodium is the coolant of choice for fast breeder reactors. Liquid sodium is highly compatible with structural steels when the concentration of dissolved non-metallic impurities such as oxygen and carbon are low. However, when their concentrations are above certain threshold limits, enhanced corrosion and mass transfer and carburization of the steels would occur. The threshold concentration levels of oxygen in sodium are determined by thermochemical aspects of various ternary oxides of Na-M-O systems (M alloying elements in steels) which take part in corrosion and mass transfer. Dissolved carbon also influences these threshold levels by establishing relevant carbide equilibria. An event of steam leak into sodium at the steam generator, if undetected at its inception itself, can lead to extensive wastage of the tubes of the steam generator and prolonged shutdown. Air ingress into the argon cover gas and leak of hydrocarbon oil used as cooling fluids of the shafts of the centrifugal pumps of sodium are the sources of oxygen and carbon impurities in sodium. Continuous monitoring of the concentration of dissolved hydrogen, carbon and oxygen in sodium coolant will help identifying their ingress at inception itself. An electrochemical hydrogen sensor based on CaHBr-CaBr 2 hydride ion conducting solid electrolyte has been developed for detecting the steam leak during normal operating conditions of the reactor. A nickel diffuser based sensor system using thermal conductivity detector (TCD) and Pd-doped tin oxide thin film sensor has been developed for use during low power operations of the reactor or during its start up. For monitoring carbon in sodium, an electrochemical sensor with molten Na 2 CO 3 -LiCO 3 as the electrolyte and pure graphite as reference electrode has been developed. Yttria Doped Thoria (YDT) electrolyte based oxygen sensor is under development for monitoring dissolved oxygen levels in sodium. Fabrication, assembly, testing and performance of

The MHD intermediate shock interaction with an intermediate wave: Are intermediate shocks physical?

International Nuclear Information System (INIS)

Wu, C.C.

1988-01-01

Contrary to the usual belief that MHD intermediate shocks are extraneous, the authors have recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear steepening from a continuous wave. In this paper, he clarifies the differences between the conventional view and the results by studying the interaction of an MHD intermediate shock with an intermediate wave. The study reaffirms his results. In addition, the study shows that there exists a larger class of shocklike solutions in the time-dependent dissiaptive MHD equations than are given by the MHD Rankine-Hugoniot relations. it also suggests a mechanism for forming rotational discontinuities through the interaction of an intermediate shock with an intermediate wave. The results are of importance not only to the MHD shock theory but also to studies such as magnetic field reconnection models

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

Optically Guided Photoactivity: Coordinating Tautomerization, Photoisomerization, Inhomogeneity, and Reactive Intermediates within the RcaE Cyanobacteriochrome.

Science.gov (United States)

Gottlieb, Sean M; Chang, Che-Wei; Martin, Shelley S; Rockwell, Nathan C; Lagarias, J Clark; Larsen, Delmar S

2014-05-01

The RcaE cyanobacteriochrome uses a linear tetrapyrrole chromophore to sense the ratio of green and red light to enable the Fremyella diplosiphon cyanobacterium to control the expression of the photosynthetic infrastructure for efficient utilization of incident light. The femtosecond photodynamics of the embedded phycocyanobilin chromophore within RcaE were characterized with dispersed femtosecond pump-dump-probe spectroscopy, which resolved a complex interplay of excited-state proton transfer, photoisomerization, multilayered inhomogeneity, and reactive intermediates. These reactions were integrated within a central model that incorporated a rapid (200 fs) excited-state Le Châtelier redistribution between parallel evolving populations ascribed to different tautomers. Three photoproducts were resolved and originates from four independent subpopulations, each with different dump-induced behavior: Lumi-Go was depleted, Lumi-Gr was unaffected, and Lumi-Gf was enhanced. This suggests that RcaE may be engineered to act either as an in vivo fluorescent probe (after single-pump excitation) or as an in vivo optogenetic sample (after pump and dump excitation).

A Markov State-based Quantitative Kinetic Model of Sodium Release from the Dopamine Transporter

Science.gov (United States)

Razavi, Asghar M.; Khelashvili, George; Weinstein, Harel

2017-01-01

The dopamine transporter (DAT) belongs to the neurotransmitter:sodium symporter (NSS) family of membrane proteins that are responsible for reuptake of neurotransmitters from the synaptic cleft to terminate a neuronal signal and enable subsequent neurotransmitter release from the presynaptic neuron. The release of one sodium ion from the crystallographically determined sodium binding site Na2 had been identified as an initial step in the transport cycle which prepares the transporter for substrate translocation by stabilizing an inward-open conformation. We have constructed Markov State Models (MSMs) from extensive molecular dynamics simulations of human DAT (hDAT) to explore the mechanism of this sodium release. Our results quantify the release process triggered by hydration of the Na2 site that occurs concomitantly with a conformational transition from an outward-facing to an inward-facing state of the transporter. The kinetics of the release process are computed from the MSM, and transition path theory is used to identify the most probable sodium release pathways. An intermediate state is discovered on the sodium release pathway, and the results reveal the importance of various modes of interaction of the N-terminus of hDAT in controlling the pathways of release.

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.

Divergent actions of the pyrethroid insecticides S-bioallethrin, tefluthrin, and deltamethrin on rat Nav1.6 sodium channels

International Nuclear Information System (INIS)

Tan Jianguo; Soderlund, David M.

2010-01-01

We expressed rat Na v 1.6 sodium channels in combination with the rat β 1 and β 2 auxiliary subunits in Xenopus laevis oocytes and evaluated the effects of the pyrethroid insecticides S-bioallethrin, deltamethrin, and tefluthrin on expressed sodium currents using the two-electrode voltage clamp technique. S-Bioallethrin, a type I structure, produced transient modification evident in the induction of rapidly decaying sodium tail currents, weak resting modification (5.7% modification at 100 μM), and no further enhancement of modification upon repetitive activation by high-frequency trains of depolarizing pulses. By contrast deltamethrin, a type II structure, produced sodium tail currents that were ∼ 9-fold more persistent than those caused by S-bioallethrin, barely detectable resting modification (2.5% modification at 100 μM), and 3.7-fold enhancement of modification upon repetitive activation. Tefluthrin, a type I structure with high mammalian toxicity, exhibited properties intermediate between S-bioallethrin and deltamethrin: intermediate tail current decay kinetics, much greater resting modification (14.1% at 100 μM), and 2.8-fold enhancement of resting modification upon repetitive activation. Comparison of concentration-effect data showed that repetitive depolarization increased the potency of tefluthrin ∼ 15-fold and that tefluthrin was ∼ 10-fold more potent than deltamethrin as a use-dependent modifier of Na v 1.6 sodium channels. Concentration-effect data from parallel experiments with the rat Na v 1.2 sodium channel coexpressed with the rat β 1 and β 2 subunits in oocytes showed that the Na v 1.6 isoform was at least 15-fold more sensitive to tefluthrin and deltamethrin than the Na v 1.2 isoform. These results implicate sodium channels containing the Na v 1.6 isoform as potential targets for the central neurotoxic effects of pyrethroids.

Review of CNEN activities in the field of sodium fires

International Nuclear Information System (INIS)

Gerosa, A.

1979-01-01

The problems related to sodium fires have received increased attention at CNEN in recent years. Sodium fires have been reported in several countries with a rate that is. relatively high if compared to the number of plants in operation. The consequences of fires have been usually quite limited but it appears that more adequate precautions could often be applied to minimize risk of more serious consequences. Many alternatives exist for fire prevention and for fire extinction, but the fact that many alternatives have not been sufficiently tested make choices rather difficult. CNEN has been facing the problem of sodium fire prevention and extinction in relation to: design of PEC reactor; design of experimental loops in its own centres (Casaccia and Brasimone); safe operation of the same loops and analysis of accidents and potential accident situations; design of facilities for sodium fire experiments; operation of sodium fire facilities; operation of sodium disposal facilities. It is worth mentioning that sodium is also utilized by italian concerns, where it is processed mostly as an intermediate product in the manufacture of tetraethyl lead. A recent accident in a TEL production plant in Italy (Trento in July 1978) has recently once more raised the question if provisions for sodium fire extinction were adequate. Small scale fires for training purposes have been performed by several experimenters at CNEN since 1965. A more systematic approach, initiated in 1973 at Brasimone Centre, has been interrupted after 1976 when studies for the construction of a larger experimental facility (SUPERSATANA) have been abandoned. In 1976 it was proposed a CNEN participation to the French Program ESMERALDA. An accord to run the ESMERALDA Project as a French-Italian common program has recently been taken. Experimental results are presented in this paper

Review of CNEN activities in the field of sodium fires

Energy Technology Data Exchange (ETDEWEB)

Gerosa, A [CNEN/CSN Casaccia, Rome (Italy)

1979-03-01

The problems related to sodium fires have received increased attention at CNEN in recent years. Sodium fires have been reported in several countries with a rate that is. relatively high if compared to the number of plants in operation. The consequences of fires have been usually quite limited but it appears that more adequate precautions could often be applied to minimize risk of more serious consequences. Many alternatives exist for fire prevention and for fire extinction, but the fact that many alternatives have not been sufficiently tested make choices rather difficult. CNEN has been facing the problem of sodium fire prevention and extinction in relation to: design of PEC reactor; design of experimental loops in its own centres (Casaccia and Brasimone); safe operation of the same loops and analysis of accidents and potential accident situations; design of facilities for sodium fire experiments; operation of sodium fire facilities; operation of sodium disposal facilities. It is worth mentioning that sodium is also utilized by italian concerns, where it is processed mostly as an intermediate product in the manufacture of tetraethyl lead. A recent accident in a TEL production plant in Italy (Trento in July 1978) has recently once more raised the question if provisions for sodium fire extinction were adequate. Small scale fires for training purposes have been performed by several experimenters at CNEN since 1965. A more systematic approach, initiated in 1973 at Brasimone Centre, has been interrupted after 1976 when studies for the construction of a larger experimental facility (SUPERSATANA) have been abandoned. In 1976 it was proposed a CNEN participation to the French Program ESMERALDA. An accord to run the ESMERALDA Project as a French-Italian common program has recently been taken. Experimental results are presented in this paper.

UK fast reactor components. Sodium removal decontamination and requalification

International Nuclear Information System (INIS)

Donaldson, D.M.; Bray, J.A.; Newson, I.H.

1978-01-01

Extensive experience gained at the U.K.A.E.A. Dounreay Nuclear Power Development Establishment is being applied to form the basis of the plant to be provided for sodium removal, decontamination, and requalification of components in future commercial fast reactors. In the first part of a three part paper, the factors to be taken into account, showing the UK philosophy and approach to maintenance and repair operations are discussed. In the second part, PFR facilities for sodium removal and decontamination are described and some examples are given of cleaning components such as pumps, charge machine, cold trap baskets, and steam generator units. Similar facilities at DFR are briefly described. In the third part of the paper a short description is given of the Harwell mass transfer loop, currently used to study the deposition of activated stainless steel corrosion products. Decontamination method for pipework specimens cut from the loop are described and results of first screening tests of various chemical decontaminants are presented. (U.K.)

Thermodiffusive behaviour of NaCl and KCl aqueous solutions a model for the Na-K pump

International Nuclear Information System (INIS)

Gaeta, F.S.; Mita, D.G.; Perna, G.; Scala, G.

1975-01-01

In NaCl and KCl aqueous nonisothermal solutions K + inverts its sense of migration within the physiological concentration range; Na + behaves similarly at much lower concentrations. These findings are discussed in relation to solute induced modifications of water structure and of their influence on thermal diffusion. A possible evolutionary model of a thermodiffusive mechanism for the sodium potassium pump is also suggested

Removal of radioruthenium from alkaline intermediate level radioactive waste solution : a laboratory investigation

International Nuclear Information System (INIS)

Samanta, S.K.; Theyyunni, T.K.

1994-01-01

Various methods were investigated in the laboratory for the removal of radioruthenium from alkaline intermediate level radioactive waste solutions of reprocessing plant origin. The methods included batch equilibration with different ion exchangers and sorbents, column testing and chemical precipitation. A column method using zinc-activated carbon mixture and a chemical precipitation method using ferrous salt along with sodium sulphite were found to be promising for plant scale application. (author). 10 refs., 3 figs., 7 tabs

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

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....

Analyses of hydrodynamic effects of large sodium-water reactions

International Nuclear Information System (INIS)

Sakano, K.; Shindo, Y.; Koishikawa, A.; Maekawa, I.

1977-01-01

Large leak sodium-water reactions that would occur in a steam generator of LMFBR causes abrupt changes of pressure and velocity of fluid in a secondary sodium system and relief system. This paper describes SOWACS-III together with its model and method. Results of analyses are also given, the comparison with experimental results of initial pressure spike being included. SOWACS-III treats the system which consists of the steam generator, vessel, valve, pump and pipe, and uses the following models and methods. (1) Components are assumed to be one-dimensional. (2) Pressure wave propagation near a reaction zone, where hydrogen is generated, is analyzed with the spherical co-ordinate (sphere-cylinder model). (3) A moving boundary is formed by contact of sodium with other fluid such as hydrogen and nitrogen. The boundary travels without mixing of sodium and another fluid through the boundary (boundary tracking model). The boundary can be treated not to move from the original place (fixed boundary model). (4) Pressure wave propagation is analyzed by the explicit method of characteristics in one-dimensional Eulerian co-ordinate. (5) Flow-induced force is analyzed by momentum balance. (6) The lateral motion of relief piping caused by the force is analyzed by NASTRAN code. Analyses were carried out for large sodium-water reaction experiments in SWAT-3 rig of PNC by using the sphere-cylinder model. The calculated pressure spike in the reaction vessel was compared with the measured one for a few milliseconds after water injection. The calculated value and measured one were 6.4 ata and 6.7 ata for peak pressure and 0.6 ms and 2.8 ms for rising time, respectively

FBR structural material test facility in flowing sodium environment

International Nuclear Information System (INIS)

Shanmugasundaram, M.; Kumar, Hemant; Ravi, S.

2016-01-01

In Fast Breeder Reactor (FBR), components such as Control and Safety Rod Drive Mechanism (CSRDM), Diverse Safety Rod Drive Mechanism (DSRDM), Transfer arm and primary sodium pumps etc., are experiencing friction and wear between the moving parts in contact with liquid sodium at high temperature. Hence, it is essential to evaluate the friction and wear behaviour to validate the design of components. In addition, the above core structural reactor components such as core cover plate, control plugs etc., undergoes thermal striping which is random thermal cycling induced by flow stream resulting from the mixing of non isothermal jets near that component. This leads to development of surface cracks and assist in crack growth which in turn may lead to failure of the structural component. Further, high temperature components are often subjected to low cycle fatigue due to temperature gradient induced cyclic thermal stresses caused by start-ups, shutdowns and transients. Also steady state operation at elevated temperature introduces creep and the combination of creep and fatigue leads to creep-fatigue interactions. Therefore, resistance to low cycle fatigue, creep and creep-fatigue are important considerations in the design of FBR components. Liquid sodium is used as coolant and hence the study of the above properties in dynamic sodium are equally important. In view of the above, facility for materials testing in sodium (INSOT) has been constructed and in operation for conducting the experiments such as tribology, thermal stripping, low cycle fatigue, creep and creep-fatigue interaction etc. The salient features of the operation and maintenance of creep and fatigue loops of INSOT facility are discussed in detail. (author)

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

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.

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

Effect of radiation on sodium and water transport in rat erythrocytes and possible repair using olive oil

International Nuclear Information System (INIS)

Othman, A.I.; El-Missiry, M.A.

1991-01-01

Gamma radiation dose 4 Gy was administered to whole rats, and sodium, water transport and sulfhydryl groups (-SH) contents of the erythrocytes were evaluated in vivo at postirradiation times 1, 3 and 7 days. The present results showed increased sodium and water gain associated with loss of sulfhydryl contents of the erythrocytes. These results are attributed to inhibition of Na pump activity and increased Na leakage into cells which increased the intracellular osmotic elements that lead to influx of water. These changes were secondary to the destruction of erythrocyte -SH groups which was investigated as a change in tertiary structure of the membrane proteins. Olive oil administered intraperitoneally resulted in restoration of the status of the studied parameters. We also noticed an increase in the amount of plasma unsaturated fatty acids including phospholipids. The relation between the reappearance of erythrocyte -SH groups and increased plasma phospholipids suggested a repair role for olive oil. This is through reconstitution of the Na-pump activity in erythrocytes by reactivation of (Na-K) ATPase stimulated by negatively charged plasma phospholipids.4 fig.,1 tab. i

Effectiveness of Chlorinated Water, Sodium Hypochlorite, Sodium ...

African Journals Online (AJOL)

This study evaluated the efficacy of chlorinated water, sodium hypochlorite solution, sodium chloride solution and sterile distilled water in eliminating pathogenic bacteria on the surfaces of raw vegetables. Lettuce vegetables were dipped in different concentrations of chlorinated water, sodium hypochlorite solution, sodium ...

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

Differential cross sections for the elastic scattering of intermediate energy electrons from sodium

International Nuclear Information System (INIS)

Teubner, P.J.O.; Buckner, S.J.; Noble, C.J.

1977-11-01

Differential cross sections for the elastic scattering of electrons from sodium have been measured with high angular resolution for incident energies of 54.4, 75, 100 and 150 eV and over an angular range of 12 0 to 140 0 . The experimental data are compared with calculations based on the First Born approximation, the Glauber approximation and a close coupling impact parameter calculation. Calculations have been carried out for an optical model using the prescription of Vanderpoorten for localizing the absorptive part of the potential. Of the theoretical calculations the optical model is found to best reproduce the general features of the cross section at all energies. (Author)

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...

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

Antimicrobial wound dressing films containing essential oils and oleoresins of pepper encapsulated in sodium alginate films

Directory of Open Access Journals (Sweden)

Jessica Miranda Rosa

2018-03-01

Full Text Available ABSTRACT: Medicated wound dressings are important barriers to avoid contamination and, when they contain antimicrobial additives, can be used as treatment for infected wounds. There are several types of polysaccharide materials that serve as matrices for medicated wound dressings, among them, sodium alginate. For the preparation of the films studied in this paper, sodium alginate was employed in combination with essential oils/oleoresins (EO/OL of six peppers that are commonly used in cooking. The EO/OL were incorporated at three different concentrations (low, intermediate and high. Most of the films prepared had better dispersion of the EO/OL at the intermediate concentration. All films studied in this research were dissolved in water at different rates. The antibacterial activity of the prepared films showed significant results against Escherichia coli, Staphylococcus aureus and Bacillus cereus, and demonstrated that the films studied may be a new alternative for medicated wound dressings.

Sodium bicarbonate-augmented stress thallium myocardial scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Sarin, Badal; Chugh, Pradeep Kumar; Kaushal, Dinesh; Soni, Nakse Lal; Sawroop, Kishan; Mondal, Anupam; Bhatnagar, Aseem [Department of Nuclear Medicine, Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, 110054, Delhi (India)

2004-04-01

It is well known that sodium bicarbonate in pharmacological doses induces transient alkalosis, causing intracellular transport of serum potassium. The aims of this study were (a) to investigate whether, in humans, myocardial thallium-201 uptake can be augmented by pretreatment with a single bolus of sodium bicarbonate at a pharmacological dose, (b) to verify general safety aspects of the intervention and (c) to evaluate the clinical implications of augmentation of {sup 201}Tl uptake, if any. Routine exercise myocardial scintigraphy was performed twice in eight adult volunteers (five normal and three abnormal), once without intervention and the second time (within a week) following intravenous administration of sodium bicarbonate (88 mEq in 50 ml) as a slow bolus 1 h prior to the injection of {sup 201}Tl. Conventional myocardial thallium study was compared with sodium bicarbonate interventional myocardial scintigraphy with respect to myocardial uptake (counts per minute per mCi injected dose), washout patterns in normal and abnormal myocardial segments, and overall clinical interpretation based on planar and single-photon emission tomographic (SPET) images. All patients remained asymptomatic after the intervention. A mean increase of 53% in myocardial uptake of thallium was noted in post-exercise acquisitions after the intervention, confirming uptake of the tracer via the potassium-hydrogen pump and its augmentation by transient alkalosis. The washout pattern remained unchanged. The visual quality of planar and SPET images improved significantly after the intervention. Out of the five abnormal myocardial segments identified in three cases, four showed significant filling-in after the intervention, causing the diagnosis to be upgraded from ''partial scar'' to ''ischaemia'', or from ''ischaemia'' to ''normal''. The overall scan impression changed in two out of three such cases. Sodium

Test and evaluation of Alco/BLH prototype sodium-heated steam generator. Final report

Energy Technology Data Exchange (ETDEWEB)

Kaplan, C.J.; Auge, L.J.; Cho, S.M.; Hanna, R.W.; Prevost, J.R.; Steger, N.A.; Wagner, R.K.

1971-01-31

A 30-Mwt prototype sodium-to-sodium intermediate heat exchanger and a 30-Mwt prototype sodium-heated steam generator were tested in combined operation in its Sodium Components Test Installation. This report contains the results of test and evaluation of the steam generator. During plant performance tests, performance degradation was observed, which resulted in the initiation of a diagnostic test series. This test series revealed that under certain operating conditions, the thermohydraulic characteristic of the steam generator changed either suddenly or gradually, resulting in overall performance degradation. A structural failure, requiring retirement of the unit, occurred before the diagnostic test series and analytical support effort were completed. This report describes the thermohydraulic and structural performance, including the structural failures, and related evaluation analyses of the Alco/BLH prototype steam generator performed prior to termination of the test and evaluation program. In addition, the report presents a post-test examination plan to obtain data that could possibly explain the cause of performance anomalies and structural failures experienced during testing.

Design study on simplification of secondary sodium cooling system for sodium cooled FBRs. Study result from JFY2000 to JFY2001

International Nuclear Information System (INIS)

Hori, Toru; Kawasaki, Nobuchika; Konomura, Mamoru

2002-09-01

For the 'Feasibility Studies on Commercialized Fast Reactor System' , various concepts with the simplified secondary sodium cooling system were designed, and the feasibility of technical issues was evaluated by focusing on improvement of economy and safety, especially elimination or mitigation of sodium-water direct interaction on heat transfer tube failure accident. In JFY 2000, 8 concepts with inert intermediate media were evaluated from standpoints of economy, safety, and structure integrity. And as promising candidates, the Pb-Bi pool type SG and the Pb-Bi tube type SG (concentric triple-walled tube) were selected, which had low cost compared with conventional IHX and SG system, and had potential of eliminating sodium-water direct interaction by separation of sodium and water tube zone. In JFY 2001, for the Pb-Bi tube type SG, important technical issues on 'Pb-Bi triple-walled tube specification suitable for safety demand', 'safety frame work corresponded to tube failure accident', and 'measures for Pb-Bi leakage into primary sodium loop' were studied, and the SG concept was constructed. In order to eliminate the design supposition of guillotine failure, available design measures for tube specification were tried to extract. But based on vibration characteristics of Pb-Bi triple-walled tube, the time required difference between outer and inner tube failure could not increase largely compared with known double-walled tube. The Pb-Bi tube type SG had potential of cost reduction (81% of cooling system, and 97% of plant), compared with conventional IHX and SG. But finally it was judged that design study on this type SG would not be executed after JFY 2002, due to impossibility of eliminating the design supposition of guillotine failure. (author)

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 ...

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

Modeling and Validation of Sodium Plugging for Heat Exchangers in Sodium-cooled Fast Reactor Systems

Energy Technology Data Exchange (ETDEWEB)

Ferroni, Paolo [Westinghouse Electric Company LLC, Cranberry Township, PA (United States). Global Technology Development; Tatli, Emre [Westinghouse Electric Company LLC, Cranberry Township, PA (United States); Czerniak, Luke [Westinghouse Electric Company LLC, Cranberry Township, PA (United States); Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States); Chien, Hual-Te [Argonne National Lab. (ANL), Argonne, IL (United States); Yoichi, Momozaki [Argonne National Lab. (ANL), Argonne, IL (United States); Bakhtiari, Sasan [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-06-29

The project “Modeling and Validation of Sodium Plugging for Heat Exchangers in Sodium-cooled Fast Reactor Systems” was conducted jointly by Westinghouse Electric Company (Westinghouse) and Argonne National Laboratory (ANL), over the period October 1, 2013- March 31, 2016. The project’s motivation was the need to provide designers of Sodium Fast Reactors (SFRs) with a validated, state-of-the-art computational tool for the prediction of sodium oxide (Na₂O) deposition in small-diameter sodium heat exchanger (HX) channels, such as those in the diffusion bonded HXs proposed for SFRs coupled with a supercritical CO₂ (sCO₂) Brayton cycle power conversion system. In SFRs, Na₂O deposition can potentially occur following accidental air ingress in the intermediate heat transport system (IHTS) sodium and simultaneous failure of the IHTS sodium cold trap. In this scenario, oxygen can travel through the IHTS loop and reach the coldest regions, represented by the cold end of the sodium channels of the HXs, where Na₂O precipitation may initiate and continue. In addition to deteriorating HX heat transfer and pressure drop performance, Na₂O deposition can lead to channel plugging especially when the size of the sodium channels is small, which is the case for diffusion bonded HXs whose sodium channel hydraulic diameter is generally below 5 mm. Sodium oxide melts at a high temperature well above the sodium melting temperature such that removal of a solid plug such as through dissolution by pure sodium could take a lengthy time. The Sodium Plugging Phenomena Loop (SPPL) was developed at ANL, prior to this project, for investigating Na₂O deposition phenomena within sodium channels that are prototypical of the diffusion bonded HX channels envisioned for SFR-sCO₂ systems. In this project, a Computational Fluid Dynamic (CFD) model capable of simulating the thermal-hydraulics of the SPPL test

Large scale breeder reactor plant prototype mechanical pump conceptual design study

Energy Technology Data Exchange (ETDEWEB)

1976-07-01

This report includes engineering memorandums, drawings, key feature descriptions, and other data. Some of the reports, such as manufacturability and some stress analysis, were done by consultants for Byron Jackson. Review of this report indicates that the design is feasible. The pump can be manufactured to system and specification requirements. The overall length and weight of some pieces will require special consideration, but is within the scope of equipment and technology available today. The fabricated parts are large and heavy, but can be manufactured and machined. Only the high temperature is unique to this size, since previous sodium pumps were smaller. Nondestructive tests as required by the Code are described and are feasible. The performance test of the prototype has been studied thoroughly. It is feasible for a cold water test. There are some problem areas. However, all of them can be solved. Development needs include building and testing a small scale model.

Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 2, Book 2. Appendices. Final report

Energy Technology Data Exchange (ETDEWEB)

1979-03-01

The appendices include: (A) design data sheets and P and I drawing for 100-MWe commercial plant design, for all-sodium storage concept; (B) design data sheets and P and I drawing for 100-MWe commercial plant design, for air-rock bed storage concept; (C) electric power generating water-steam system P and I drawing and equipment list, 100-MWe commercial plant design; (D) design data sheets and P and I drawing for 281-MWe commercial plant design; (E) steam generator system conceptual design; (F) heat losses from solar receiver surface; (G) heat transfer and pressure drop for rock bed thermal storage; (H) a comparison of alternative ways of recovering the hydraulic head from the advanced solar receiver tower; (I) central receiver tower study; (J) a comparison of mechanical and electromagnetic sodium pumps; (K) pipe routing study of sodium downcomer; and (L) sodium-cooled advanced central receiver system simulation model. (WHK)

Sodium leakage experience at the prototype FBR Monju

International Nuclear Information System (INIS)

Miyakawa, A.; Maeda, H.; Kani, Y.; Ito, K.

2000-01-01

Monju is Japan's prototype fast breeder reactor: 280 MWe (714 MWt), fueled with mixed oxides of plutonium and uranium, cooled by liquid sodium. Construction was started in 1985 and initial criticality was attained in April 1994. On 8th December 1995, sodium leakage from a secondary circuit occurred in a piping room of the reactor auxiliary building. The secondary sodium leaked through a temperature sensor, due to the breakaway of the tip of the thermocouple well tube installed near the secondary circuit outlet of the intermediate heat exchanger (IHX). The reactor remained cooled and thus, from the viewpoint of radiological hazards, the safety of the reactor was secured. There was no release of radioactive material. There were no adverse effects for personnel and the surrounding environment. The thermocouple well tube failure resulted from high cycle fatigue due to flow induced vibration. It was found that this flow induced vibration was not caused by well-known Von Karman vortex shedding, but a symmetric vortex shedding. The design of the thermocouple well, which was subject to avoid this phenomenon, was reviewed. A new design guide against the flow-induced vibration was prepared by JNC (Japan Nuclear Cycle Development Institute). This is more comprehensive and definitive than the existing guide 'ASME N-1300' (Flow-induced vibration of tube and tube banks). New thermocouple well designs were proposed consistent with this design guide. To prevent a recurrence of the secondary sodium leakage incident, comprehensive design review activities were started for the purpose of checking the safety and reliability of the plant. As a result, several aspects to be improved were identified and improvements and countermeasures have been studied. The main improvements and countermeasures are as follows: To enable the operators to understand and react to incidents quickly, new sodium leakage detectors (TV monitors, smoke sensors) and a new surveillance system will be installed; To

The Experimental Characterization of the Magnetic Field Effect on a Liquid Sodium Flow

International Nuclear Information System (INIS)

Kim, Hee Reyoung; Kim, Jong Man; Cha, Jae Eun; Choi, Jong Hyun; Nam, Ho Yoon

2006-01-01

A liquid sodium coolant is used for a LMR such as KALIMER and a magnetic field is generated in the electromagnetic pump or flowmeter. The magnetic field has an effect on the electrically conducting metal flow by a generation of an electromagnetic pressure drop. Therefore, in the present study, a theoretical calculation is carried out for the effect of an external magnetic field and the magnetic field is measured over the electromagnet system manufactured for the magnetohydrodynamic experiments

The Theoretical Investigation of the Magnetic Field Effect on a Liquid Sodium Flow

International Nuclear Information System (INIS)

Kim, Hee Reyoung; Kim, Jong Man; Cha, Jae Eun; Choi, Jong Hyun; Nam, Ho Yoon

2005-01-01

The liquid sodium coolant is used for LMR such as KALIMER and magnetic field is generated in the electromagnetic pump or flowmeter. The magnetic field takes an effect on the electrically conducting metal flow by the generation of the electromagnetic pressure drop. Therefore, in the present study, the theoretical calculation is carried out for an effect from the external magnetic field and the magnetic field is firstly measured over the electromagnet system manufactured for the magnetohydrodynamic experiments

Centrifugal pumps

CERN Document Server

Gülich, Johann Friedrich

2014-01-01

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

Predictors of sudden death and death from pump failure in congestive heart failure are different. Analysis of 24 h Holter monitoring, clinical variables, blood chemistry, exercise test and radionuclide angiography

DEFF Research Database (Denmark)

Madsen, B K; Rasmussen, Verner; Hansen, J F

1997-01-01

Association class II and 44% in III. Total mortality after 1 year was 21%, after 2 years 32%. Of 60 deaths, 33% were sudden and 49% due to pump failure. Multivariate analyses identified totally different risk factors for sudden death: ventricular tachycardia, s-sodium ....6 mmol/l, s-potassium sudden death and for death from progressive pump failure........80 mmol/l, s-creatinine > 121 mumol/l, and maximal change in heart rate during exercise death from progressive pump failure: New York Heart Association class III + IV, delta heart rate over 24 h 7...

Radioactive sodium waste treatment and conditioning. Review of main aspects

International Nuclear Information System (INIS)

2007-01-01

This publication reviews the main aspects relating to the treatment and conditioning of radioactive sodium waste. This waste arises from the operation of liquid metal fast reactors (LMFRs). In this type of reactor, sodium (Na) or sodium-potassium alloys (NaK) are used as a low-effect neutron moderating coolant medium for extracting and transferring thermal energy from the core and they represent a significant technical and safety challenge during operation and decommissioning. This publication provides the reader with technologically oriented information on the present status of sodium waste management approaches and recent achievements related to treatment and conditioning, with the objective of facilitating planning and preparatory work for the decommissioning of LMFRs. This publication provides a comprehensive review of the hazards associated with sodium waste management. Given the large quantities of sodium waste arising during decommissioning or reactor refurbishment, as well as the challenges and varied techniques associated with removal of 100% of all sodium and NaK bulk quantities and residues during decommissioning, a hazards review and analysis is a critical component in planning the dismantling and waste management activities. Roughly half of this publication focuses on sodium waste generating, handling and treatment processes. This includes draining sodium and NaK from plant systems; in situ treatment of residual sodium; cutting techniques for pumps, valves, piping and other components; cleaning of components; potential reuse of sodium; and removal of selected radionuclides from sodium waste with the objective of reducing the waste classification or converting it to exempt waste. The focus is on proven techniques and technologies, and each discussed method includes a review of the associated principle or theory, practical applications, advantages and disadvantages, limitations, industry experience, and final waste products. A review is provided of final

In and out of the cation pumps: P-type ATPase structure revisited

DEFF Research Database (Denmark)

Bublitz, Maike; Poulsen, Hanne; Morth, Jens Preben

2010-01-01

. The marked increment during the last three years in the number of crystal structures of P-type ATPases has greatly improved our understanding of the similarities and differences of pumps with different ion specificities, since the structures of the Ca2+-ATPase, the Na+,K+-ATPase and the H+-ATPase can now......Active transport across membranes is a crucial requirement for life. P-type ATPases build up electrochemical gradients at the expense of ATP by forming and splitting a covalent phosphoenzyme intermediate, coupled to conformational changes in the transmembrane section where the ions are translocated...... be compared directly. Mechanisms for ion gating, charge neutralization and backflow prevention are starting to emerge from comparative structural analysis; and in combination with functional studies of mutated pumps this provides a framework for speculating on how the ions are bound and released as well...

Pumping characteristics of roots blower pumps for light element gases

International Nuclear Information System (INIS)

Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu; Nakamura, Jun-ichi; Ohbayashi, Tetsuro

2002-07-01

The pumping speed and compression ratio of the two-stage roots blower pumping system were measured for light element gases (H 2 , D 2 and He) and for N 2 , in order to assess validity of the ITER torus roughing system as an ITER R and D task (T234). The pumping system of an Edwards EH1200 (nominal pumping speed of 1200 m 3 /s), two EH250s (ibid. 250 m 3 /s) and a backing pump (ibid. 100 m 3 /s) in series connection was tested under PNEUROP standards. The maximum pumping speeds of the two-stage system for D 2 and N 2 were 1200 and 1300 m 3 /h, respectively at 60 Hz, which satisfied the nominal pumping speed. These experimental data support the design validity of the ITER torus roughing system. (author)

PUMPS

Science.gov (United States)

Thornton, J.D.

1959-03-24

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

Pump characteristics and applications

CERN Document Server

Volk, Michael

2013-01-01

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

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...

Pumping behavior of sputtering ion pump

Energy Technology Data Exchange (ETDEWEB)

Chou, T.S.; Bittner, J.; Schuchman, J.

1991-12-31

To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.

Pumping behavior of sputtering ion pump

Energy Technology Data Exchange (ETDEWEB)

Chou, T.S.; Bittner, J.; Schuchman, J.

1991-01-01

To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.

Intermediate Leg SBLOCA - Long Lasting Pressure Transient

International Nuclear Information System (INIS)

Konjarek, D.; Bajs, T.; Vukovic, J.

2010-01-01

The basic phenomenology of Small Break Loss of Coolant Accident (SBLOCA) for PWR plant is described with focus on analysis of scenario in which reactor coolant pressure decreases below secondary system pressure. Best estimate light water reactor transient analysis code RELAP5/mod3.3 was used in calculation. Rather detailed model of the plant was used. The break occurs in intermediate leg on lowest elevation near pump suction. The size of the break is chosen to be small enough to cause cycling of safety valves (SVs) on steam generators (SGs) for some time, but, afterwards, it is large enough to remove decay heat through the break, causing cooling the secondary side. In this case of SBLOCA, when primary pressure decreases below secondary pressure, long lasting pressure transients with significant amplitude occur. Reasons for such behavior are explained.(author).

Sodium

Science.gov (United States)

Table salt is a combination of two minerals - sodium and chloride Your body needs some sodium to work properly. It helps with the function ... in your body. Your kidneys control how much sodium is in your body. If you have too ...

Multiple pump housing

Science.gov (United States)

Donoho, II, Michael R.; Elliott; Christopher M.

2010-03-23

A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

Assessing the energy efficiency of pumps and pump units background and methodology

CERN Document Server

Bernd Stoffel, em Dr-Ing

2015-01-01

Assessing the Energy Efficiency of Pumps and Pump Units, developed in cooperation with Europump, is the first book available providing the background, methodology, and assessment tools for understanding and calculating energy efficiency for pumps and extended products (pumps+motors+drives). Responding to new EU requirements for pump efficiency, and US DOE exploratory work in setting pump energy efficiency guidelines, this book provides explanation, derivation, and illustration of PA and EPA methods for assessing energy efficiency. It surveys legislation related to pump energy eff

Sodium component reliability data collection at CREDO

International Nuclear Information System (INIS)

Bott, T.F.; Haas, P.M.; Manning, J.J.

1979-01-01

The Centralized Reliability Data Organization (CREDO) has been established at Oak Ridge National Laboratory (ORNL) by the Department of Energy to provide a national center for collection, evaluation and dissemination of reliability data for advanced reactors. While the system is being developed and continuous data collection at the two U.S. reactor sites (EBR-II and FFTF) is being established, data on advanced reactor components which have been in use at U.S. test loops and experimental reactors have been collected and analyzed. Engineering, operating and event data on sodium valves, pumps, flow meters, rupture discs, heat exchangers and cold traps have been collected from more than a dozen sites. The results of analyses of the data performed to date are presented

Effect of Non-linear Velocity Loss Changes in Pumping Stage of Hydraulic Ram Pumps on Pumping Discharge Rate

Directory of Open Access Journals (Sweden)

Reza Fatahialkouhi

2018-03-01

Full Text Available The ram pump is a device which pumps a portion of input discharge to the pumping system in a significant height by using renewable energy of water hammer. The complexities of flow hydraulic on one hand and on the other hand the use of simplifying assumptions in ram pumps have caused errors in submitted analytical models for analyzing running cycle of these pumps. In this study it has been tried to modify the governing analytical model on hydraulic performance of these pumps in pumping stage. In this study by creating a logical division, the cycle of the ram pump was divided into three stages of acceleration, pumping and recoil and the governing equations on each stage of cycling are presented by using method of characteristics. Since the closing of impulse valve is nonlinear, velocity loss in pumping stage is considered nonlinearly. Also the governing equations in pumping stage were modified by considering disc elasticity of impulse valve and changing volume of the pump body when the water hammer phenomenon is occurred. In order to evaluate results and determine empirical factors of the proposed analytical model, a physical model of the ram pump is made with internal diameter of 51 mm. Results of this study are divided into several parts. In the first part, loss coefficients of the impulse valve were measured experimentally and empirical equations of drag coefficient and friction coefficient of the impulse valve were submitted by using nonlinear regression. In the second part, results were evaluated by using experimental data taken from this study. Evaluation of statistical error functions showed that the proposed model has good accuracy for predicting experimental observations. In the third part, in order to validate the results in pumping stage, the analytical models of Lansford and Dugan (1941 and Tacke (1988 were used and the error functions resulted from prediction of experimental observations were investigated through analytical models of

Corrosion of Steels in the Vicinity of a Sodium-Water Reaction

Energy Technology Data Exchange (ETDEWEB)

Davies, R. A.; Bray, J. A.; Lyons, J. M. [U.K. Atomic Energy Authority, Dounreay Experimental Reactor Establishment, Thurso, Caithness (United Kingdom)

1967-06-15

Rapid corrosion of steels in the vicinity of a sodium-water reaction could lead to a major reaction in a sodium-water heat exchanger. An investigation of the magnitude of the corrosion problem has been carried out under conditions simulating both a small water leak and a full size pipe burst, and further tube failures have been obtained. These experiments were carried out on a sodium rig which could accommodate simple full-scale models of sections of heat exchanger, and up to 70 lb of water was injected into 700 lb of sodium in 9.0s. The corrosion phenomena have also been investigated on a small scale under more controllable conditions by pumping water at normal pressures into a pot of sodium. With a flow-rate of 1 ml/min corrosion rates in excess of 0.005 in./min have been obtained. The effect of various parameters on the corrosion rate has been studied, and a comparison has been made of the corrosion rates obtained with a variety of steels. The corrosion appears to be a direct result of conditions during the reaction, and the appearance of the specimen and pattern of damage suggests that the main effect is concentrated where the sodium water reaction front impinges on the metal surface. The corrosion rates are very much lower with stainless steel and nickel alloys than with ferritic materials, and suggest that the phenomena are associated with the formation of (Na{sub 2}O){sub 2}FeO. Iron powder has also been observed in the vicinity of the reaction which would suggest that this is reduced at a later stage, either as a result of the hydrogen produced during reaction, or by thermal cycling. (author)

Methodology for Extraction of Remaining Sodium of Used Sodium Containers

International Nuclear Information System (INIS)

Jung, Minhwan; Kim, Jongman; Cho, Youngil; Jeong, Jiyoung

2014-01-01

Sodium used as a coolant in the SFR (Sodium-cooled Fast Reactor) reacts easily with most elements due to its high reactivity. If sodium at high temperature leaks outside of a system boundary and makes contact with oxygen, it starts to burn and toxic aerosols are produced. In addition, it generates flammable hydrogen gas through a reaction with water. Hydrogen gas can be explosive within the range of 4.75 vol%. Therefore, the sodium should be handled carefully in accordance with standard procedures even though there is a small amount of target sodium remainings inside the containers and drums used for experiment. After the experiment, all sodium experimental apparatuses should be dismantled carefully through a series of draining, residual sodium extraction, and cleaning if they are no longer reused. In this work, a system for the extraction of the remaining sodium of used sodium drums has been developed and an operation procedure for the system has been established. In this work, a methodology for the extraction of remaining sodium out of the used sodium container has been developed as one of the sodium facility maintenance works. The sodium extraction system for remaining sodium of the used drums was designed and tested successfully. This work will contribute to an establishment of sodium handling technology for PGSFR. (Prototype Gen-IV Sodium-cooled Fast Reactor)

Interpretation of the measurement of ions fluxes through a biological membrane with a cellular compartment: example of the movements of sodium through the skin of frogs

International Nuclear Information System (INIS)

Morel, F.

1959-01-01

Two-way ion fluxes which can be measured in vitro through a living epithelial membrane (such as frog skin) by the indicator method take place across the cells which behave like an intermediate ionic 'compartment'. Two membranes and four fluxes have thus to be considered. Measurements in vitro of the total sodium fluxes as a function of the sodium concentration in the medium in contact with the external face of the skin have been interpreted in this spirit. Making use of certain hypotheses, the permeability coefficients for sodium of the two cellular membranes, the four sodium fluxes, the intracellular sodium concentration and the membrane potentials have been calculated for each value of the sodium concentration in the external medium. (author) [fr

Superphenix 1 intermediate heat exchanger fabrication

International Nuclear Information System (INIS)

Noel, H.; Granito, F.; Pouderoux, P.

1985-01-01

The eight Superphenix 375-MW (thermal) intermediate heat exchangers (IHXs) are similar in overall design to the Phenix components. Detailed design changes had to be made during fabrication on the following grounds: Due to seismic resistance, the support area was raised as high as possible to situate the component natural frequencies well out of the resonance peak range and remove thick plate-to-shell connections from heavy thermal load areas. Integration of lessons drawn from the Phenix incidents, due mainly to secondary sodium radial temperature disparities, resulted in the design of a more adaptable outlet header, together with a sodium mixing device, and in the reduction of temperature differences by heat insulation. To avoid circumferential temperature disparities, the iron shot biological shielding plug was replaced by stacked stainless steel plates within an outer shell, which in the new design, is not a supporting structure. The thermal-hydraulic and mechanical design of the component necessitated the elaboration of sophisticated computer codes, with validation of results on mock-ups. The detailed design studies and the actual manufacturing work had to adapt to both design developments and to inherent fabrication difficulties, mainly related to the very tight tolerances imposed for these exceptionally large components and to the welding of steel with an excessive boron content. The construction of the Creys-Malville IHXs afforded valuable industrial experience, which should provide a basis for the design of simpler and less costly IHX units for the forthcoming 1500-MW (electric) breeder

Performance Analysis Of Single-Pumped And Dual-Pumped Parametric Optical Amplifier

Directory of Open Access Journals (Sweden)

Sandar Myint

2015-06-01

Full Text Available Abstract In this study we present a performance analysis of single-pumped and dual- pumped parametric optical amplifier and present the analysis of gain flatness in dual- pumped Fiber Optical Parametric Amplifier FOPA based on four-wave mixing FWM. Result shows that changing the signal power and pump power give the various gains in FOPA. It is also found out that the parametric gain increase with increase in pump power and decrease in signal power. .Moreover in this paper the phase matching condition in FWM plays a vital role in predicting the gain profile of the FOPAbecause the parametric gain is maximum when the total phase mismatch is zero.In this paper single-pumped parametric amplification over a 50nm gain bandwidth is demonstrated using 500 nm highly nonlinear fiber HNLF and signal achieves about 31dB gain. For dual-pumped parametric amplification signal achieves 26.5dB gains over a 50nm gain bandwidth. Therefore dual-pumped parametric amplifier can provide relatively flat gain over a much wider bandwidth than the single-pumped FOPA.

Residual heat removal pump and low pressure safety injection pump retrofit program

International Nuclear Information System (INIS)

Dudiak, J.G.; McKenna, J.M.

1992-01-01

Residual Heat Removal (RHR) and low pressure safety injection (LPSI) pumps installed in pressurized water-to-reactor power plants are used to provide low-head safety injection in the event of loss of coolant in the reactor coolant system. Because these pumps are subjected to rather severe temperature and pressure transients, the majority of pumps installed in the RHR service are vertical pumps with a single stage impeller. Typically the pump impeller is mounted on an extended motor shaft (close-coupled configuration) and a mechanical seal is employed at the pump end of the shaft. Traditionally RHR and LPSI pumps have been a significant maintenance item for many utilities. Periodic mechanical seal of motor bearing replacement often is considered routine maintenance. The closed-coupled pump design requires disassembly of the casing cover from the lower pump casing while performing these routine maintenance tasks. This paper introduces a design modification developed to convert the close-coupled RHR and LPSI pumps to a coupled configuration

Structural and functional aspects of the multidrug efflux pump AcrB.

Science.gov (United States)

Eicher, Thomas; Brandstätter, Lorenz; Pos, Klaas M

2009-08-01

The tripartite efflux system AcrA/AcrB/TolC is the main pump in Escherichia coli for the efflux of multiple antibiotics, dyes, bile salts and detergents. The inner membrane component AcrB is central to substrate recognition and energy transduction and acts as a proton/drug antiporter. Recent structural studies show that homotrimeric AcrB can adopt different monomer conformations representing consecutive states in an allosteric functional rotation transport cycle. The conformational changes create an alternate access drug transport tunnel including a hydrophobic substrate binding pocket in one of the cycle intermediates.

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

OpenAIRE

Rusovs, D

2009-01-01

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

Palladium(II)-catalyzed desulfitative synthesis of aryl ketones from sodium arylsulfinates and nitriles: scope, limitations, and mechanistic studies.

Science.gov (United States)

Skillinghaug, Bobo; Sköld, Christian; Rydfjord, Jonas; Svensson, Fredrik; Behrends, Malte; Sävmarker, Jonas; Sjöberg, Per J R; Larhed, Mats

2014-12-19

A fast and efficient protocol for the palladium(II)-catalyzed production of aryl ketones from sodium arylsulfinates and various organic nitriles under controlled microwave irradiation has been developed. The wide scope of the reaction has been demonstrated by combining 14 sodium arylsulfinates and 21 nitriles to give 55 examples of aryl ketones. One additional example illustrated that, through the choice of the nitrile reactant, benzofurans are also accessible. The reaction mechanism was investigated by electrospray ionization mass spectrometry and DFT calculations. The desulfitative synthesis of aryl ketones from nitriles was also compared to the corresponding transformation starting from benzoic acids. Comparison of the energy profiles indicates that the free energy requirement for decarboxylation of 2,6-dimethoxybenzoic acid and especially benzoic acid is higher than the corresponding desulfitative process for generating the key aryl palladium intermediate. The palladium(II) intermediates detected by ESI-MS and the DFT calculations provide a detailed understanding of the catalytic cycle.

Heat pumps

CERN Document Server

Macmichael, DBA

1988-01-01

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

Sodium fire tests for investigating the sodium leak in Monju

International Nuclear Information System (INIS)

Seino, Hiroshi; Miyahara, Shinya; Miyake, Osamu; Tanabe, Hiromi

1996-01-01

As a part of the work for investigating the sodium leak accident which occurred in Monju on December 8, 1995, three tests, (1) sodium leak test, (2) sodium fire test-I, and (3) sodium fire test-II, were carried out at OEC/PNC. Main objectives of these tests are to confirm leak and burning behavior of sodium from the damaged thermometer, and effects of the sodium fire on integrity of the surrounding structure, etc. The main conclusions obtained from the tests are shown as below. 1) Average sodium leak rate obtained from the sodium leak test was about 50 g/sec. This was equivalent to the value estimated from level change in the sodium overflow tank in the Monju accident. 2) Observation from video cameras in the sodium fire tests revealed that in early stages of sodium leak, sodium dropped down out of the flexible tube of thermometer in drips. This dripping and burning were expanded in range as sodium splashed on the duct. 3) Though, in the sodium fire test-I, there was a decrease of about 1 mm at a thickness of the burning pan in the vicinity in just under in the leak point, there were completely no crack and failure. In the meantime, in the sodium fire test-II the six open holes were found in the floor liner. By this liner failure, the reaction between sodium and concrete might take place. At present, while the detailed evaluation on the sodium fire test-II has been mainly carried out, the investigation for clarifying the cause of the liner failure has been also carried out. (author)

Reactor coolant purification system circulation pumps (CUW pumps)

International Nuclear Information System (INIS)

Tsutsui, Toshiaki

1979-01-01

Coolant purification equipments for BWRs have been improved, and the high pressure purifying system has become the main type. The quantity of purifying treatment also changed to 2% of the flow rate of reactor feed water. As for the circulation pumps, canned motor pumps are adopted recently, and the improvements of reliability and safety are attempted. The impurities carried in by reactor feed water and the corrosion products generated in reactors and auxiliary equipments are activated by neutron irradiation or affect heat transfer adversely, adhering to fuel claddings are core structures. Therefore, a part of reactor coolant is led to the purification equipments, and returned to reactors after the impurities are eliminated perfectly. At the time of starting and stopping reactors, excess reactor water and the contaminated water from reactors are transferred to main condenser hot wells or waste treatment systems. Thus the prescribed water quality is maintained. The operational modes of and the requirements for the CUW pumps, the construction and the features of the canned motor type CUW pumps are explained. Recently, a pump operated for 11 months without any maintenance has been disassembled and inspected, but the wear of bearings has not been observed, and the high reliability of the pump has been proved. (Kako, I.)

On the Mechanism of Human Red Blood Cell Longevity: Roles of Calcium, the Sodium Pump, PIEZO1, and Gardos Channels

Directory of Open Access Journals (Sweden)

Virgilio L. Lew

2017-12-01

Full Text Available In a healthy adult, the transport of O2 and CO2 between lungs and tissues is performed by about 2 · 1013 red blood cells, of which around 1.7 · 1011 are renewed every day, a turnover resulting from an average circulatory lifespan of about 120 days. Cellular lifespan is the result of an evolutionary balance between the energy costs of maintaining cells in a fit functional state versus cell renewal. In this Review we examine how the set of passive and active membrane transporters of the mature red blood cells interact to maximize their circulatory longevity thus minimizing costs on expensive cell turnover. Red blood cell deformability is critical for optimal rheology and gas exchange functionality during capillary flow, best fulfilled when the volume of each human red blood cell is kept at a fraction of about 0.55–0.60 of the maximal spherical volume allowed by its membrane area, the optimal-volume-ratio range. The extent to which red blood cell volumes can be preserved within or near these narrow optimal-volume-ratio margins determines the potential for circulatory longevity. We show that the low cation permeability of red blood cells allows volume stability to be achieved with extraordinary cost-efficiency, favouring cell longevity over cell turnover. We suggest a mechanism by which the interplay of a declining sodium pump and two passive membrane transporters, the mechanosensitive PIEZO1 channel, a candidate mediator of Psickle in sickle cells, and the Ca2+-sensitive, K+-selective Gardos channel, can implement red blood cell volume stability around the optimal-volume-ratio range, as required for extended circulatory longevity.

Development of advanced heat pump (2). Prelimirary test of two-stage compression heat pump. Koseino onreinetsu kyokyu heat pump system no kaihatsu. Dai 2 ho 2dan attsusyuku system shisakuki no yobi jikken kekka

Energy Technology Data Exchange (ETDEWEB)

Iwatsubo, Tetsushiro; Saikawa, Michinori; Hamamatsu, Teruhide

1988-03-01

A heat pump driven by electricity is one of the excellent electricity utilization systems and is promoted to be widely used. An advanced heat pump has been investigated to enlarge its applications in the field of hot water supply for domestic use which will be competitive with city gas and air conditioning in large scale buildings. An experimental unit with two-stage compression system was designed, which has the multi-function of air conditioning and hot water supply, and the trial system was fabricated. In the design, followings were considered; cooperative operations of two compressors by inverter driving, the temperature conditions of both the air for the air conditioning and the heat source, additional setting of the intermediate heat exchanger. The test operation was carried out with checking the start up procedure, the control sequence and so on. The probability of five operation modes: cooling, heating, hot water supply, cooling/hot water supply, and heating/hot water supply, were confirmed. In the mode of heating/hot water supply the hot water temperature was increased to 65/sup 0/C, the excellent performance in hot water supply was demonstrated. (21 figs, 8 tabs, 1 photo, 5 refs)

Intermediate honeycomb ordering to trigger oxygen redox chemistry in layered battery electrode.

Science.gov (United States)

Mortemard de Boisse, Benoit; Liu, Guandong; Ma, Jiangtao; Nishimura, Shin-ichi; Chung, Sai-Cheong; Kiuchi, Hisao; Harada, Yoshihisa; Kikkawa, Jun; Kobayashi, Yoshio; Okubo, Masashi; Yamada, Atsuo

2016-04-18

Sodium-ion batteries are attractive energy storage media owing to the abundance of sodium, but the low capacities of available cathode materials make them impractical. Sodium-excess metal oxides Na2MO3 (M: transition metal) are appealing cathode materials that may realize large capacities through additional oxygen redox reaction. However, the general strategies for enhancing the capacity of Na2MO3 are poorly established. Here using two polymorphs of Na2RuO3, we demonstrate the critical role of honeycomb-type cation ordering in Na2MO3. Ordered Na2RuO3 with honeycomb-ordered [Na(1/3)Ru(2/3)]O2 slabs delivers a capacity of 180 mAh g(-1) (1.3-electron reaction), whereas disordered Na2RuO3 only delivers 135 mAh g(-1) (1.0-electron reaction). We clarify that the large extra capacity of ordered Na2RuO3 is enabled by a spontaneously ordered intermediate Na1RuO3 phase with ilmenite O1 structure, which induces frontier orbital reorganization to trigger the oxygen redox reaction, unveiling a general requisite for the stable oxygen redox reaction in high-capacity Na2MO3 cathodes.

Sodium technology handbook

International Nuclear Information System (INIS)

2005-09-01

This document was published as a textbook for the education and training of personnel working for operations and maintenances of sodium facilities including FBR plants and those engaged in R and D activities related to sodium technology. This handbook covers the following technical areas. Properties of sodium. Compatibilities of sodium with materials. Thermalhydraulics and structural integrity. Sodium systems and components. Sodium instrumentations. Sodium handling technology. Sodium related accident evaluation and countermeasures for FBRs. Operation, maintenance and repair technology of sodium facilities. Safety measures related to sodium. Laws, regulations and internal rules related to sodium. The plannings and discussions of the handbook were made in the Sodium Technology Education Committee organized in O-arai Engineering Center consisting of the representatives of the related departments including Tsuruga headquarters. Experts in various departments participated in writing individual technical subjects. (author)

The detection of sodium vapor bubble collapse in a liquid metal fast breeder reactor

International Nuclear Information System (INIS)

Carey, W.M.; Gavin, A.P.; Bobis, J.P.; Sheen, S.H.; Anderson, T.T.; Doolittle, R.D.; Albrecht, R.W.

1977-01-01

Sodium boiling detection utilizing the sound pressure emanated during the collapse of a sodium vapour bubble in a subcooled media is discussed in terms of the sound characteristic, the reactor ambient noise background, transmission loss considerations and performance criteria. Data obtained in several loss of flow experiments on Fast Test Reactor Fuel Elements indicate that the collapse of the sodium vapour bubble depends on the presence of a subcooled structure or sodium. The collapse pressure pulse was observed in all cases to be on the order of a kPa, indicating a soft type of cavitational collapse. Spectral examination of the pulses indicates the response function of the test structure and geometry is important. The sodium boiling observed in these experiments was observed to occur at a low ( 0 C) liquid superheat with the rate of occurrence of sodium vapor bubble collapse in the 3 to 30 Hz range. Reactor ambient noise data were found to be due to machinery induced vibrations flow induced vibrations, and flow noise. These data were further found to be weakly stationary enhancing the possibility of acoustic surveillance of an operating Liquid Metal Fast Breeder Reactor. Based on these noise characteristics and extrapolating the noise measurements from the Fast Flux Test Facility Pump (FFTP), one would expect a signal to noise ratio of up to 20 dB in the absence of transmission loss. The requirement of a low false alarm probability is shown to necessitate post detection analysis of the collapse event sequence and the cross correlation with the second derivative of the neutronic boiling detection signal. Sodium boiling detection using the sounds emitted during sodium vapor bubble collapse are shown to be feasible but a need for in-reactor demonstration is necessary. (author)