tangential flow injection: Topics by WorldWideScience.org

Sample records for tangential flow injection

Fuelling effect of tangential compact toroid injection in STOR-M Tokamak

Energy Technology Data Exchange (ETDEWEB)

Onchi, T.; Liu, Y., E-mail: tao668@mail.usask.ca [Univ. of Saskatchewan, Dept. of Physics and Engineering Physics, Saskatoon, Saskatchewan (Canada); Dreval, M. [Univ. of Saskatchewan, Dept. of Physics and Engineering Physics, Saskatoon, Saskatchewan (Canada); Inst. of Plasma Physics NSC KIPT, Kharkov (Ukraine); McColl, D. [Univ. of Saskatchewan, Dept. of Physics and Engineering Physics, Saskatoon, Saskatchewan (Canada); Asai, T. [Inst. of Plasma Physics NSC KIPT, Kharkov (Ukraine); Wolfe, S. [Nihon Univ., Dept. of Physics, Tokyo (Japan); Xiao, C.; Hirose, A. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada)

2012-07-01

Compact torus injection (CTI) is the only known candidate for directly fuelling the core of a tokamak fusion reactor. Compact torus (CT) injection into the STOR-M tokamak has induced improved confinement accompanied by an increase in the electron density, reduction in Hα emission, and suppression of the saw-tooth oscillations. The measured change in the toroidal flow velocity following tangential CTI has demonstrated momentum injection into the STOR-M plasma. (author)
Generation of a rotating liquid liner by tangential injection

International Nuclear Information System (INIS)

Burton, R.L.; Turchi, P.J.; Jenkins, D.J.; Lanham, R.E.; Cameron, J.; Cooper, A.L.

1979-01-01

Efficient compression of low mass-density payloads by the implosion of higher mass-density liquid cylinders or liners, as in the NRL LINUS concept for controlled thermonuclear fusion, requires rotation of the liner material to avoid Rayleigh--Taylor instabilities at the liner-payload interface. Experimentally, such implosions have been demonstrated with liners formed within rotating implosion chambers. The present work uses a scale-model experimental apparatus to investigate the possibility of creating liner rotation by tangential injection of the liquid liner material. Different modes of behavior are obtained depending on the fluid exhaust procedures. Right-circular, cylindrical free surfaces are achieved with axial exhaust of fluid at radii interior to the injection nozzles, for which the liner exhibits a combination of solid-body and free vortex flows in different regions. Measurements allow estimates of power losses to viscous shear, turbulence, etc. A simple model based on open-channel flow is then derived, which is in good agreement with experiment, and is used to extrapolate results to the scale of a possible LINUS fusion reactor
Dynamic membrane filtration in tangential flow

International Nuclear Information System (INIS)

Anon.

1993-01-01

Oil-containing waste water is produced in many cleaning processes and also on production of compressed air. Dynamic membrane filtration in the tangential flow mode has proved effective in the treatment of these stable emulsions. The possible applications of ceramic membrane filters are illustrated for a variety of examples. (orig.) [de
Cavitation control on a 2D hydrofoil through a continuous tangential injection of liquid: Experimental study

Science.gov (United States)

Timoshevskiy, M. V.; Zapryagaev, I. I.; Pervunin, K. S.; Markovich, D. M.

2016-10-01

In the paper, the possibility of active control of a cavitating flow over a 2D hydrofoil that replicates a scaled-down model of high-pressure hydroturbine guide vane (GV) was tested. The flow manipulation was implemented by a continuous tangential liquid injection at different flow rates through a spanwise slot in the foil surface. In experiments, the hydrofoil was placed in the test channel at the attack angle of 9°. Different cavitation conditions were reached by varying the cavitation number and injection velocity. In order to study time dynamics and spatial patterns of partial cavities, high-speed imaging was employed. A PIV method was used to measure the mean and fluctuating velocity fields over the hydrofoil. Hydroacoustic measurements were carried out by means of a pressure transducer to identify spectral characteristics of the cavitating flow. It was found that the present control technique is able to modify the partial cavity pattern (or even totally suppress cavitation) in case of stable sheet cavitation and change the amplitude of pressure pulsations at unsteady regimes. The injection technique makes it also possible to significantly influence the spatial distributions of the mean velocity and its turbulent fluctuations over the GV section for non-cavitating flow and sheet cavitation.
Drag reduction and thrust generation by tangential surface motion in flow past a cylinder

Science.gov (United States)

Mao, Xuerui; Pearson, Emily

2018-03-01

Sensitivity of drag to tangential surface motion is calculated in flow past a circular cylinder in both two- and three-dimensional conditions at Reynolds number Re ≤ 1000 . The magnitude of the sensitivity maximises in the region slightly upstream of the separation points where the contour lines of spanwise vorticity are normal to the cylinder surface. A control to reduce drag can be obtained by (negatively) scaling the sensitivity. The high correlation of sensitivities of controlled and uncontrolled flow indicates that the scaled sensitivity is a good approximation of the nonlinear optimal control. It is validated through direct numerical simulations that the linear range of the steady control is much higher than the unsteady control, which synchronises the vortex shedding and induces lock-in effects. The steady control injects angular momentum into the separating boundary layer, stabilises the flow and increases the base pressure significantly. At Re=100 , when the maximum tangential motion reaches 50% of the free-stream velocity, the vortex shedding, boundary-layer separation and recirculation bubbles are eliminated and 32% of the drag is reduced. When the maximum tangential motion reaches 2.5 times of the free-stream velocity, thrust is generated and the power savings ratio, defined as the ratio of the reduced drag power to the control input power, reaches 19.6. The mechanism of drag reduction is attributed to the change of the radial gradient of spanwise vorticity (partial r \\hat{ζ } ) and the subsequent accelerated pressure recovery from the uncontrolled separation points to the rear stagnation point.
DEMONSTRATION OF SORBENT INJECTION TECHNOLOGY ON A TANGENTIALLY COAL-FIRED UTILITY BOILER (YORKTOWN LIMB DEMONSTRATION)

Science.gov (United States)

The report summarizes activities conducted and results achieved in an EPA-sponsored program to demonstrate Limestone Injection Multistage Burner (LIMB) technology on a tangentially fired coal-burning utility boiler, Virginia Power's 180-MWe Yorktown Unit No. 2. his successfully d...
Reverse-Tangent Injection in a Centrifugal Compressor

Science.gov (United States)

Skoch, Gary J.

2007-01-01

Injection of working fluid into a centrifugal compressor in the reverse tangent direction has been invented as a way of preventing flow instabilities (stall and surge) or restoring stability when stall or surge has already commenced. The invention applies, in particular, to a centrifugal compressor, the diffuser of which contains vanes that divide the flow into channels oriented partly radially and partly tangentially. In reverse-tangent injection, a stream or jet of the working fluid (the fluid that is compressed) is injected into the vaneless annular region between the blades of the impeller and the vanes of the diffuser. As used here, "reverse" signifies that the injected flow opposes (and thereby reduces) the tangential component of the velocity of the impeller discharge. At the same time, the injected jet acts to increase the radial component of the velocity of the impeller discharge.
Cavitating flow control through continuous tangential mass injection on a 2D hydrofoil at a small attack angle

Directory of Open Access Journals (Sweden)

Timoshevskiy Mikhail V.

2016-01-01

Full Text Available We studied cavitating flow over the suction side of a symmetric 2D foil – a scaled-down model of high-pressure hydroturbine guide vanes (GV – in different cavitation regimes at the attack angle of 3°. High-speed imaging was used to analyze spatial patterns and time dynamics of the gas-vapour cavities. A hydroacoustic pressure transducer was employed to register time-spectra of pressure fluctuations nearby the hydrofoil. A PIV technique was applied to measure the velocity fields and its fluctuations. The active flow control was implemented by means of a continuous liquid supply with different flow rates through a slot channel located in the GV surface. It was found that the active mass injection does not influence the primary flow upstream of the slot channel position. For the cavitation-free and cavitation inception cases, the injection was shown to make the turbulent wake past the GV section more intense. However, at the developed cavitation regimes the active flow management made it possible to reduce substantially the amplitude or even totally suppress the periodic cavity length oscillations and pressure pulsations associated with them.
Tangential Flow Filtration of Colloidal Silver Nanoparticles: A "Green" Laboratory Experiment for Chemistry and Engineering Students

Science.gov (United States)

Dorney, Kevin M.; Baker, Joshua D.; Edwards, Michelle L.; Kanel, Sushil R.; O'Malley, Matthew; Pavel Sizemore, Ioana E.

2014-01-01

Numerous nanoparticle (NP) fabrication methodologies employ "bottom-up" syntheses, which may result in heterogeneous mixtures of NPs or may require toxic capping agents to reduce NP polydispersity. Tangential flow filtration (TFF) is an alternative "green" technique for the purification, concentration, and size-selection of…
Cascade ultrafiltering of 210Pb and 210Po in freshwater using a tangential flow filtering system

International Nuclear Information System (INIS)

Ohtsuka, Y.; Takaku, Y.; Hisamatsu, S.; Inaba, J.; Yamamoto, M.

2006-01-01

A rapid method was developed using ultrafilters with a tangential flow filtering system for molecular size separation of naturally occurring 210 Pb and 210 Po in a freshwater sample. Generally, ultrafiltering of a large volume water sample for measuring the nuclides was too time consuming and not practical. The tangential flow filtering system made the filtering time short enough to adapt for in-situ ultrafiltering the large volume sample. In this method, a 20 liter water sample was at first passed through the 0.45 μm pore size membrane filter immediately after sample collection to obtain suspended particle matter [>0.45 μm particulate fraction (PRT)]. Two ultrafilters (Millipore Pellicon 2 R ) were used sequentially. The nuclides in the filtrate were separated into three fractions: high molecular mass (100 kDa-0.45μm; HMM), low molecular mass (10 k-100 kDa; LMM) and ionic ( 210 Pb and 210 Po in an oligotrophic lake, Lake Towada located in the northern area of Japan. (author)
Evolution and transition mechanisms of internal swirling flows with tangential entry

Science.gov (United States)

Wang, Yanxing; Wang, Xingjian; Yang, Vigor

2018-01-01

The characteristics and transition mechanisms of different states of swirling flow in a cylindrical chamber have been numerically investigated using the Galerkin finite element method. The effects of the Reynolds number and swirl level were examined, and a unified theory connecting different flow states was established. The development of each flow state is considered as a result of the interaction and competition between basic mechanisms: (1) the centrifugal effect, which drives an axisymmetric central recirculation zone (CRZ); (2) flow instabilities, which develop at the free shear layer and the central solid-body rotating flow; (3) the bouncing and restoring effects of the injected flow, which facilitate the convergence of flow on the centerline and the formation of bubble-type vortex breakdown; and (4) the damping effect of the end-induced flow, which suppresses the development of the instability waves. The results show that the CRZ, together with the free shear layer on its surface, composes the basic structure of swirling flow. The development of instability waves produces a number of discrete vortex cores enclosing the CRZ. The azimuthal wave number is primarily determined by the injection angle. Generally, the wave number is smaller at a higher injection angle, due to the reduction of the perimeter of the free shear layer. At the same time, the increase in the Reynolds number facilitates the growth of the wave number. The end-induced flow tends to reduce the wave number near the head end and causes a change in wave number from the head end to the downstream region. Spiral-type vortex breakdown can be considered as a limiting case at a high injection angle, with a wave number equal to 0 near the head end and equal to 1 downstream. At lower Reynolds numbers, the bouncing and restoring effect of the injected flow generates bubble-type vortex breakdown.
The three-dimensional distributions of tangential velocity and total- temperature in vortex tubes

DEFF Research Database (Denmark)

Linderstrøm-Lang, C.U.

1971-01-01

The axial and radial gradients of the tangential velocity distribution are calculated from prescribed secondary flow functions on the basis of a zero-order approximation to the momentum equations developed by Lewellen. It is shown that secondary flow functions may be devised which meet pertinent...... physical requirements and which at the same time lead to realistic tangential velocity gradients. The total-temperature distribution in both the axial and radial directions is calculated from such secondary flow functions and corresponding tangential velocity results on the basis of an approximate...
Experimental Study of the Swirling Oxidizer Flow in HTPB/N2O Hybrid Rocket Motor

Directory of Open Access Journals (Sweden)

Mohammad Mahdi Heydari

2017-01-01

Full Text Available Effects of swirling oxidizer flow on the performance of a HTPB/N2O Hybrid rocket motor were studied. A hybrid propulsion laboratory has been developed, to characterize internal ballistics characteristics of swirl flow hybrid motors and to define the operating parameters, like fuel regression rate, specific impulse, and characteristics velocity and combustion efficiency. Primitive variables, like pressure, thrust, temperature, and the oxidizer mass flow rate, were logged. A modular motor with 70 mm outer diameter and variable chamber length is designed for experimental analysis. The injector module has four tangential injectors and one axial injector. Liquid nitrous oxide (N2O as an oxidizer is injected at the head of combustion chamber into the motor. The feed system uses pressurized air as the pressurant. Two sets of tests have been performed. Some tests with axial and tangential oxidizer injection and a test with axial oxidizer injection were done. The test results show that the fuel grain regression rate has been improved by applying tangential oxidizer injection at the head of the motor. Besides, it was seen that combustion efficiency of motors with the swirl flow was about 10 percent more than motors with axial flow.
Fast ion confinement during high power tangential neutral beam injection into low plasma current discharges on the ISX-B tokamak

International Nuclear Information System (INIS)

Carnevali, A.; Scott, S.D.; Neilson, H.; Galloway, M.; Stevens, P.; Thomas, C.E.

1988-01-01

The beam ion thermalization process during tangential neutral beam injection in the ISX-B tokamak is investigated. The classical model is tested in co- and counter-injected discharges at low plasma current, a regime where large orbit width excursions enhance the importance of the loss regions. To test the model, experimental charge exchange spectra are compared with the predictions of an orbit following Monte Carlo code. Measurements of beam-plasma neutron emission and measured decay rates of the emission following beam turnoff provide additional information. Good agreement is found between theory and experiment. Furthermore, beam additivity experiments show that, globally, the confinement of beam ions remains classical, independently of the injected beam power. However, some experimental evidence suggests that the fast ion density in the plasma core did not increase with beam power in a way consistent with classical processes. (author). 35 refs, 17 figs, 3 tabs
Design of tangential viewing phase contrast imaging for turbulence measurements in JT-60SA

Energy Technology Data Exchange (ETDEWEB)

Tanaka, K., E-mail: ktanaka@nifs.ac.jp [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Department of Advanced Energy Engineering, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Coda, S. [EPFL–SPC, Lausanne (Switzerland); Yoshida, M.; Sasao, H.; Kawano, Y.; Imazawa, R.; Kubo, H.; Kamada, Y. [National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193 (Japan)

2016-11-15

A tangential viewing phase contrast imaging system is being designed for the JT-60SA tokamak to investigate microturbulence. In order to obtain localized information on the turbulence, a spatial-filtering technique is applied, based on magnetic shearing. The tangential viewing geometry enhances the radial localization. The probing laser beam is injected tangentially and traverses the entire plasma region including both low and high field sides. The spatial resolution for an Internal Transport Barrier discharge is estimated at 30%–70% of the minor radius at k = 5 cm{sup −1}, which is the typical expected wave number of ion scale turbulence such as ion temperature gradient/trapped electron mode.
A Modified EPA Method 1623 that Uses Tangential Flow Hollow-Fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidum and Giardia spp.

Science.gov (United States)

This protocol describes the use of a tangential flow hollow-fiber ultrafiltration sample concentration system and a heat dissociation as alternative steps for the detection of waterborne Cryptosporidium and Giardia species using EPA Method 1623.
Microalgae fractionation using steam explosion, dynamic and tangential cross-flow membrane filtration.

Science.gov (United States)

Lorente, E; Hapońska, M; Clavero, E; Torras, C; Salvadó, J

2017-08-01

In this study, the microalga Nannochloropsis gaditana was subjected to acid catalysed steam explosion treatment and the resulting exploded material was subsequently fractionated to separate the different fractions (lipids, sugars and solids). Conventional and vibrational membrane setups were used with several polymeric commercial membranes. Two different routes were followed: 1) filtration+lipid solvent extraction and 2) lipid solvent extraction+filtration. Route 1 revealed to be much better since the used membrane for filtration was able to permeate the sugar aqueous phase and retained the fraction containing lipids; after this, an extraction required a much lower amount of solvent and a better recovering yield. Filtration allowed complete lipid rejection. Dynamic filtration improved permeability compared to the tangential cross-flow filtration. Best membrane performance was achieved using a 5000Da membrane with the dynamic system, obtaining a permeability of 6L/h/m 2 /bar. Copyright © 2017 Elsevier Ltd. All rights reserved.
Tangential neutral-beam--driven instabilities in the Princeton beta experiment

International Nuclear Information System (INIS)

Heidbrink, W.W.; Bol, K.; Buchenauer, D.

1986-01-01

During tangential neutral-beam injection into the PBX tokamak, bursts of two types of instabilities are observed. One instability occurs in the frequency range 120--210 kHz and the other oscillates predominantly near the frequency of bulk plasma rotation (20--30 kHz). Both instabilities correlate with drops in neutron emission and bursts in charge-exchange neutral flux, indicating that beam ions are removed from the center of the plasma by the instabilities. The central losses are comparable to the losses induced by the fishbone instability during perpendicular injection
Tangential stretching rate (TSR) analysis of non premixed reactive flows

KAUST Repository

Valorani, Mauro

2016-10-16

We discuss how the Tangential stretching rate (TSR) analysis, originally developed and tested for spatially homogeneous systems (batch reactors), is extended to spatially non homogeneous systems. To illustrate the effectiveness of the TSR diagnostics, we study the ignition transient in a non premixed, reaction–diffusion model in the mixture fraction space, whose dependent variables are temperature and mixture composition. The reactive mixture considered is syngas/air. A detailed H2/CO mechanism with 12 species and 33 chemical reactions is employed. We will discuss two cases, one involving only kinetics as a model of front propagation purely driven by spontaneous ignition, the other as a model of deflagration wave involving kinetics/diffusion coupling. We explore different aspects of the system dynamics such as the relative role of diffusion and kinetics, the evolution of kinetic eigenvalues, and of the tangential stretching rates computed by accounting for the combined action of diffusion and kinetics as well for kinetics only. We propose criteria based on the TSR concept which allow to identify the most ignitable conditions and to discriminate between spontaneous ignition and deflagration front.
The impact of interpreted flow regimes during constant head injection tests on the estimated transmissivity from injection tests and difference flow logging

Energy Technology Data Exchange (ETDEWEB)

Hjerne, Calle; Ludvigsson, Jan-Erik; Harrstroem, Johan [Geosigma AB, Uppsala (Sweden)

2013-04-15

A large number of constant head injection tests were carried out in the site investigation at Forsmark using the Pipe String System, PSS3. During the original evaluation of the tests the dominating transient flow regimes during both the injection and recovery period were interpreted together with estimation of hydraulic parameters. The flow regimes represent different flow and boundary conditions during the tests. Different boreholes or borehole intervals may display different distributions of flow regimes. In some boreholes good agreement was obtained between the results of the injection tests and difference flow logging with Posiva flow log (PFL) but in other boreholes significant discrepancies were found. The main objective of this project is to study the correlation between transient flow regimes from the injection tests and other borehole features such as transmissivity, depth, geology, fracturing etc. Another subject studied is whether observed discrepancies between estimated transmissivity from difference flow logging and injection tests can be correlated to interpreted flow regimes. Finally, a detailed comparison between transient and stationary evaluation of transmissivity from the injection tests in relation to estimated transmissivity from PFL tests in corresponding sections is made. Results from previous injection tests in 5 m sections in boreholes KFM04, KFM08A and KFM10A were used. Only injection tests above the (test-specific) measurement limit regarding flow rate are included in the analyses. For all of these tests transient flow regimes were interpreted. In addition, results from difference flow logging in the corresponding 5 m test sections were used. Finally, geological data of fractures together with rock and fracture zone properties have been used in the correlations. Flow regimes interpreted from the injection period of the tests are generally used in the correlations but deviations between the interpreted flow regimes from the injection and

Analysis of residual swirl in tangentially-fired natural gas-boiler

International Nuclear Information System (INIS)

Hasril Hasini; Muhammad Azlan Muad; Mohd Zamri Yusoff; Norshah Hafeez Shuaib

2010-01-01

This paper describes the investigation on residual swirl flow in a 120 MW natural gas, full-scale, tangential-fired boiler. Emphasis is given towards the understanding of the behavior of the combustion gas flow pattern and temperature distribution as a result of the tangential firing system of the boiler. The analysis was carried out based on three-dimensional computational modeling on full scale boiler with validation from key design parameter as well as practical observation. Actual operating parameters of the actual boiler are taken as the boundary conditions for this modeling. The prediction of total heat flux was found to be in agreement with the key design parameter while the residual swirl predicted at the upper furnace agrees qualitatively with the practical observation. Based on this comparison, detail analysis was carried out for comprehensive understanding on the generation and destruction of the residual swirl behavior in boiler especially those with high capacity. (author)
Modeling Bottom Sediment Erosion Process by Swirling the Flow by Tangential Supply of Oil in the Tank

Science.gov (United States)

Nekrasov, V. O.

2016-10-01

The article carries out a statistical data processing of quantitative and territorial division of oil tanks operating in Tyumen region, intended for reception, storage and distribution of commercial oil through trunk pipelines. It describes the working principle of the new device of erosion and prevention of oil bottom sediment formation with tangential supply of oil pumped into reservoir. The most significant similarity criteria can be emphasized in modeling rotational flows exerting significant influence on the structure of the circulating flow of oil in tank when operation of the device described. The dependence of the distribution of the linear velocity of a point on the surface along the radius at the circular motion of the oil in the tank is characterized, and on the basis of this dependence, a formula of general kinetic energy of rotational motion of oil and asphalt-resin-paraffin deposits total volume in the oil reservoir is given.
The Impact of Beam Deposition on Bootstrap Current of Fast Ion Produced by Neutral Beam Tangential Injection

International Nuclear Information System (INIS)

Huang Qian-Hong; Gong Xue-Yu; Lu Xing-Qiang; Yu Jun; Cao Jin-Jia

2015-01-01

The density profile of fast ions arising from a tangentially injected diffuse neutral beam in tokamak plasma is calculated. The effects of mean free paths and beam tangency radius on the density profile are discussed under typical HL-2A plasmas parameters. The results show that the profile of fast ions is strongly peaked at the center of the plasma when the mean free path at the maximum deuteron density is larger than the minor radius, while the peak value decreases when the mean free path at the maximum deuteron density is larger than twice that of the minor radius due to the beam transmission loss. Moreover, the bootstrap current of fast ions for various mean free paths at the maximum deuteron density is calculated and its density is proved to be closely related to the deposition of the neutral beam. With the electron return current considered, the net current density obviously decreases. Meanwhile, the peak central fast ion density increases when the beam tangency radius approaches the major radius, and the net bootstrap current increases rapidly with the increasing beam tangency radius. (paper)
Tangential neutral-beam-driven instabilities in the princeton beta experiment

OpenAIRE

Heidbrink, WW; Bol, K; Buchenauer, D; Fonck, R; Gammel, G; Ida, K; Kaita, R; Kaye, S; Kugel, H; LeBlanc, B; Morris, W; Okabayashi, M; Powell, E; Sesnic, S; Takahashi, H

1986-01-01

During tangential neutral-beam injection into the PBX tokamak, bursts of two types of instabilities are observed. One instability occurs in the frequency range 120-210 kHz and the other oscillates predominantly near the frequency of bulk plasma rotation (20-30 kHz). Both instabilities correlate with drops in neutron emission and bursts in charge-exchange neutral flux, indicating that beam ions are removed from the center of the plasma by the instabilities. The central losses are comparable to...
Purification of infectious adenovirus in two hours by ultracentrifugation and tangential flow filtration

International Nuclear Information System (INIS)

Ugai, Hideyo; Yamasaki, Takahito; Hirose, Megumi; Inabe, Kumiko; Kujime, Yukari; Terashima, Miho; Liu, Bingbing; Tang, Hong; Zhao, Mujun; Murata, Takehide; Kimura, Makoto; Pan, Jianzhi; Obata, Yuichi; Hamada, Hirofumi; Yokoyama, Kazunari K.

2005-01-01

Adenoviruses are excellent vectors for gene transfer and are used extensively for high-level expression of the products of transgenes in living cells. The development of simple and rapid methods for the purification of stable infectious recombinant adenoviruses (rAds) remains a challenge. We report here a method for the purification of infectious adenovirus type 5 (Ad5) that involves ultracentrifugation on a cesium chloride gradient at 604,000g for 15 min at 4 deg C and tangential flow filtration. The entire procedure requires less than two hours and infectious Ad5 can be recovered at levels higher than 64% of the number of plaque-forming units (pfu) in the initial crude preparation of viruses. We have obtained titers of infectious purified Ad5 of 1.35 x 10 10 pfu/ml and a ratio of particle titer to infectious titer of seven. The method described here allows the rapid purification of rAds for studies of gene function in vivo and in vitro, as well as the rapid purification of Ad5
A volumetric flow sensor for automotive injection systems

International Nuclear Information System (INIS)

Schmid, U; Krötz, G; Schmitt-Landsiedel, D

2008-01-01

For further optimization of the automotive power train of diesel engines, advanced combustion processes require a highly flexible injection system, provided e.g. by the common rail (CR) injection technique. In the past, the feasibility to implement injection nozzle volumetric flow sensors based on the thermo-resistive measurement principle has been demonstrated up to injection pressures of 135 MPa (1350 bar). To evaluate the transient behaviour of the system-integrated flow sensors as well as an injection amount indicator used as a reference method, hydraulic simulations on the system level are performed for a CR injection system. Experimentally determined injection timings were found to be in good agreement with calculated values, especially for the novel sensing element which is directly implemented into the hydraulic system. For the first time pressure oscillations occurring after termination of the injection pulse, predicted theoretically, could be verified directly in the nozzle. In addition, the injected amount of fuel is monitored with the highest resolution ever reported in the literature
A volumetric flow sensor for automotive injection systems

Science.gov (United States)

Schmid, U.; Krötz, G.; Schmitt-Landsiedel, D.

2008-04-01

For further optimization of the automotive power train of diesel engines, advanced combustion processes require a highly flexible injection system, provided e.g. by the common rail (CR) injection technique. In the past, the feasibility to implement injection nozzle volumetric flow sensors based on the thermo-resistive measurement principle has been demonstrated up to injection pressures of 135 MPa (1350 bar). To evaluate the transient behaviour of the system-integrated flow sensors as well as an injection amount indicator used as a reference method, hydraulic simulations on the system level are performed for a CR injection system. Experimentally determined injection timings were found to be in good agreement with calculated values, especially for the novel sensing element which is directly implemented into the hydraulic system. For the first time pressure oscillations occurring after termination of the injection pulse, predicted theoretically, could be verified directly in the nozzle. In addition, the injected amount of fuel is monitored with the highest resolution ever reported in the literature.
Ammonia-methane combustion in tangential swirl burners for gas turbine power generation

OpenAIRE

Valera Medina, Agustin; Marsh, Richard; Runyon, Jon; Pugh, Daniel; Beasley, Paul; Hughes, Timothy Richard; Bowen, Philip John

2017-01-01

Ammonia has been proposed as a potential energy storage medium in the transition towards a low-carbon economy. This paper details experimental results and numerical calculations obtained to progress towards optimisation of fuel injection and fluidic stabilisation in swirl burners with ammonia as the primary fuel. A generic tangential swirl burner has been employed to determine flame stability and emissions produced at different equivalence ratios using ammonia–methane blends. Experiments were...
Flow Injection Analysis in Industrial Biotechnology

DEFF Research Database (Denmark)

Hansen, Elo Harald; Miró, Manuel

2009-01-01

Flow injection analysis (FIA) is an analytical chemical continuous-flow (CF) method which in contrast to traditional CF-procedures does not rely on complete physical mixing (homogenisation) of the sample and the reagent(s) or on attaining chemical equilibria of the chemical reactions involved. Ex...
Retinal Changes Induced by Epiretinal Tangential Forces

Directory of Open Access Journals (Sweden)

Mario R. Romano

2015-01-01

Full Text Available Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-posterior forces. However, tangential forces are less characterized and classified in literature compared to the anterior-posterior ones. Tangential epiretinal forces are mainly due to anomalous posterior vitreous detachment (PVD, vitreoschisis, vitreopapillary adhesion (VPA, and epiretinal membranes (ERMs. Anomalous PVD plays a key role in the formation of the tangential vectorial forces on the retinal surface as consequence of gel liquefaction (synchysis without sufficient and fast vitreous dehiscence at the vitreoretinal interface. The anomalous and persistent adherence of the posterior hyaloid to the retina can lead to vitreomacular/vitreopapillary adhesion or to a formation of avascular fibrocellular tissue (ERM resulting from the proliferation and transdifferentiation of hyalocytes resident in the cortical vitreous remnants after vitreoschisis. The right interpretation of the forces involved in the epiretinal tangential tractions helps in a better definition of diagnosis, progression, prognosis, and surgical outcomes of vitreomacular interfaces.
Sequential injection lab-on-valve: the third generation of flow injection analysis

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald

2003-01-01

Termed the third generation of flow injection analysis, sequential injection (SI)-lab-on-valve (LOV) has specific advantages and allows novel, unique applications - not least as a versatile front end to a variety of detection techniques. This review presents snd discusses progress to date of the ...
Automated injection of slurry samples in flow-injection analysis

NARCIS (Netherlands)

Hulsman, M.H.F.M.; Hulsman, M.; Bos, M.; van der Linden, W.E.

1996-01-01

Two types of injectors are described for introducing solid samples as slurries in flow analysis systems. A time-based and a volume-based injector based on multitube solenoid pinch valves were built, both can be characterized as hydrodynamic injectors. Reproducibility of the injections of dispersed
Flow injection analysis in inductively coupled plasma spectrometry

International Nuclear Information System (INIS)

Rosias, Maria F.G.G.

1995-10-01

The main features of flow injection analysis (FIA) as contribution to the inductively coupled plasma (Icp) spectrometry are described. A systematic review of researches using the combined FIA-Icp and the benefits of this association are presented. Flow systems were proposed to perform on-line Icp solution management for multielemental determination by atomic emission spectrometry (Icp-AES) or mass spectrometry. The inclusion of on-line ion exchangers in flow systems for matrix separation and/or analyte preconcentration are presented. Together with those applications the new advent of instruments with facilities for multielement detection on flow injection signals are described. (author). 75 refs., 19 figs
Flow improvers for water injection based on surfactants

Energy Technology Data Exchange (ETDEWEB)

Oskarsson, H.; Uneback, I.; Hellsten, M.

2006-03-15

In many cases it is desirable to increase the flow of injection water when an oil well deteriorates. It is very costly in offshore operation to lay down an additional water pipe to the injection site. Flow improvers for the injection water will thus be the most cost-effective way to increase the flow rate. During the last years water-soluble polymers have also been applied for this purpose. These drag-reducing polymers are however only slowly biodegraded which has been an incentive for the development of readily biodegradable surfactants as flow improvers for injection water. A combination of a zwitterionic and an anionic surfactant has been tested in a 5.5 inch, 700 m long flow loop containing sulphate brine with salinity similar to sea water. A drag reduction between 75 and 80% was achieved with 119 ppm in solution of the surfactant blend at an average velocity of 1.9 m/s and between 50 and 55% at 2.9 m/s. The surfactants in this formulation were also found to be readily biodegradable in sea water and low bio accumulating which means they have an improved environmental profile compared to the polymers used today. Due to the self-healing properties of the drag-reducing structures formed by surfactants, these may be added before the pump section - contrary to polymers which are permanently destroyed by high shear forces. (Author)
Effect of the helicity injection rate and the Lundquist number on spheromak sustainment

Science.gov (United States)

García-Martínez, Pablo Luis; Lampugnani, Leandro Gabriel; Farengo, Ricardo

2014-12-01

The dynamics of the magnetic relaxation process during the sustainment of spheromak configurations at different helicity injection rates is studied. The three-dimensional activity is recovered using time-dependent resistive magnetohydrodynamic simulations. A cylindrical flux conserver with concentric electrodes is used to model configurations driven by a magnetized coaxial gun. Magnetic helicity is injected by tangential boundary flows. Different regimes of sustainment are identified and characterized in terms of the safety factor profile. The spatial and temporal behavior of fluctuations is described. The dynamo action is shown to be in close agreement with existing experimental data. These results are relevant to the design and operation of helicity injected devices, as well as to basic understanding of the plasma relaxation mechanism in quasi-steady state.
Effect of the helicity injection rate and the Lundquist number on spheromak sustainment

Energy Technology Data Exchange (ETDEWEB)

García-Martínez, Pablo Luis, E-mail: pablogm@cab.cnea.gov.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Sede Andina—Universidad Nacional de Río Negro (UNRN), Av. Bustillo 9500, 8400 San Carlos de Bariloche, Río Negro (Argentina); Lampugnani, Leandro Gabriel; Farengo, Ricardo [Instituto Balseiro and Centro Atómico Bariloche (CAB-CNEA), Av. Bustillo 9500, 8400 San Carlos de Bariloche, Río Negro (Argentina)

2014-12-15

The dynamics of the magnetic relaxation process during the sustainment of spheromak configurations at different helicity injection rates is studied. The three-dimensional activity is recovered using time-dependent resistive magnetohydrodynamic simulations. A cylindrical flux conserver with concentric electrodes is used to model configurations driven by a magnetized coaxial gun. Magnetic helicity is injected by tangential boundary flows. Different regimes of sustainment are identified and characterized in terms of the safety factor profile. The spatial and temporal behavior of fluctuations is described. The dynamo action is shown to be in close agreement with existing experimental data. These results are relevant to the design and operation of helicity injected devices, as well as to basic understanding of the plasma relaxation mechanism in quasi-steady state.
Purged window apparatus. [On-line spectroscopic analysis of gas flow systems

Science.gov (United States)

Ballard, E.O.

1982-04-05

A purged window apparatus is described which utilizes tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube thereby preventing backstreaming of flowing gases under investigation in a chamber to which a plurality of similar purged apparatus is attached with the consequent result that spectroscopic analyses can be undertaken for lengthy periods without the necessity of interrupting the flow for cleaning or replacing the windows due to contamination.
Experimental Highlights upon Tangential Percussions in Mechanical Systems

Directory of Open Access Journals (Sweden)

Stelian Alaci

2014-12-01

Full Text Available The paper presents a proposed method for underlying the presence of tangential percussions occurring in multibody systems. Tangential percussions define a relatively newly introduced concept required by the necessity of explaining the sudden change in the state of motion for two bodies interacting only on a direction from the common tangent plane. In robotics domain, normal and tangential percussions are widely met in the case of robotic hands in the moment of contacting the manipulated object.
Tests of the frozen-flux and tangentially geostrophic assumptions using magnetic satellite data

DEFF Research Database (Denmark)

Chulliat, A.; Olsen, Nils; Sabaka, T.

In 1984, Jean-Louis Le Mouël published a paper suggesting that the flow at the top of the Earth’s core is tangentially geostrophic, i.e., the Lorentz force is much smaller than the Coriolis force in this particular region of the core. This new assumption wassubsequently used to discriminate among...
3D-CFD Simulation of Confined Cross-Flow Injection Process Using Single Piston Pump

Directory of Open Access Journals (Sweden)

M. Elashmawy

2017-12-01

Full Text Available Injection process into a confined cross flow is quite important for many applications including chemical engineering and water desalination technology. The aim of this study is to investigate the performance of the injection process into a confined cross-flow of a round pipe using a single piston injection pump. A computational fluid dynamics (CFD analysis has been carried out to investigate the effect of the locations of the maximum velocity and minimum pressure on the confined cross-flow process. The jet trajectory is analyzed and related to the injection pump shaft angle of rotation during the injection duty cycle by focusing on the maximum instant injection flow of the piston action. Results indicate a low effect of the jet trajectory within the range related to the injection pump operational conditions. Constant cross-flow was used and injection flow is altered to vary the jet to line flow ratio (QR. The maximum jet trajectory exhibits low penetration inside the cross-flow. The results showed three regions of the flow ratio effect zones with different behaviors. Results also showed that getting closer to the injection port causes a significant decrease on the locations of the maximum velocity and minimum pressure.

Status of the tangentially fired LIMB Demonstration Program at Yorktown Unit No. 2: An update

International Nuclear Information System (INIS)

Clark, J.P.; Gogineni, M.R.; Koucky, R.W.; Gootzait, E.; Lachapelle, D.G.

1992-01-01

Combustion Engineering, Inc., under EPA sponsorship, is conducting a program to demonstrate furnace sorbent injection on a tangentially fired, coal-burning utility boiler, Virginia Power's 180 MW(e) Yorktown Unit No. 2. The overall objective of the program is to demonstrate significant reductions in sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) while minimizing any negative impacts on boiler performance. Engineering and procurement activities and baseline testing have been completed. Construction and installation of the sorbent injection and low-NO x equipment is nearly complete. An 8-month demonstration of furnace sorbent injection plus flue gas humidification will be conducted in 1992. Details of the sorbent injection concept to be tested at Yorktown, results of baseline testing, overall demonstration program organization and schedule, and preliminary plans for the 8-month demonstration test are discussed in the paper
Bi-tangential hybrid IMRT for sparing the shoulder in whole breast irradiation.

Science.gov (United States)

Farace, P; Deidda, M A; Iamundo de Cumis, I; Iamundo de Curtis, I; Deiana, E; Farigu, R; Lay, G; Porru, S

2013-11-01

A bi-tangential technique is proposed to reduce undesired doses to the shoulder produced by standard tangential irradiation. A total of 6 patients affected by shoulder pain and reduced functional capacity after whole-breast irradiation were retrospectively analysed. The standard tangential plan used for treatment was compared with (1) a single bi-tangential plan where, to spare the shoulder, the lateral open tangent was split into two half-beams at isocentre, with the superior portion rotated by 10-20° medially with respect to the standard lateral beam; (2) a double bi-tangential plan, where both the tangential open beams were split. The planning target volume (PTV) coverage and the dose to the portion of muscles and axilla included in the standard tangential beams were compared. PTV95 % of standard plan (91.9 ± 3.8) was not significantly different from single bi-tangential plan (91.8 ± 3.4); a small but significant (p < 0.01) decrease was observed with the double bi-tangential plan (90.1 ± 3.7). A marked dose reduction to the muscle was produced by the single bi-tangential plan around 30-40 Gy. The application of the double bi-tangential technique further reduced the volume receiving around 20 Gy, but did not markedly affect the higher doses. The dose to the axilla was reduced both in the single and the double bi-tangential plans. The single bi-tangential technique would have been able to reduce the dose to shoulder and axilla, without compromising target coverage. This simple technique is valuable for irradiation after axillary lymph node dissection or in patients without dissection due to negative or low-volume sentinel lymph node disease.
Bi-tangential hybrid IMRT for sparing the shoulder in whole breast irradiation

Energy Technology Data Exchange (ETDEWEB)

Farace, P.; Deidda, M. A.; Iamundo de Curtis, I.; Deiana, E.; Farigu, R.; Lay, G.; Porru, S. [Regional Oncological Hospital, Cagliari (Italy). Dept. of Radio-Oncology

2013-11-15

Background and purpose: A bi-tangential technique is proposed to reduce undesired doses to the shoulder produced by standard tangential irradiation. Patients and methods: A total of 6 patients affected by shoulder pain and reduced functional capacity after whole-breast irradiation were retrospectively analysed. The standard tangential plan used for treatment was compared with (1) a single bi-tangential plan where, to spare the shoulder, the lateral open tangent was split into two half-beams at isocentre, with the superior portion rotated by 10-20 medially with respect to the standard lateral beam; (2) a double bi-tangential plan, where both the tangential open beams were split. The planning target volume (PTV) coverage and the dose to the portion of muscles and axilla included in the standard tangential beams were compared. Results: PTV95 % of standard plan (91.9 {+-} 3.8) was not significantly different from single bi-tangential plan (91.8 {+-} 3.4); a small but significant (p < 0.01) decrease was observed with the double bi-tangential plan (90.1 {+-} 3.7). A marked dose reduction to the muscle was produced by the single bi-tangential plan around 30-40 Gy. The application of the double bi-tangential technique further reduced the volume receiving around 20 Gy, but did not markedly affect the higher doses. The dose to the axilla was reduced both in the single and the double bi-tangential plans. Conclusion: The single bi-tangential technique would have been able to reduce the dose to shoulder and axilla, without compromising target coverage. This simple technique is valuable for irradiation after axillary lymph node dissection or in patients without dissection due to negative or low-volume sentinel lymph node disease. (orig.)
Bi-tangential hybrid IMRT for sparing the shoulder in whole breast irradiation

International Nuclear Information System (INIS)

Farace, P.; Deidda, M.A.; Iamundo de Curtis, I.; Deiana, E.; Farigu, R.; Lay, G.; Porru, S.

2013-01-01

Background and purpose: A bi-tangential technique is proposed to reduce undesired doses to the shoulder produced by standard tangential irradiation. Patients and methods: A total of 6 patients affected by shoulder pain and reduced functional capacity after whole-breast irradiation were retrospectively analysed. The standard tangential plan used for treatment was compared with (1) a single bi-tangential plan where, to spare the shoulder, the lateral open tangent was split into two half-beams at isocentre, with the superior portion rotated by 10-20 medially with respect to the standard lateral beam; (2) a double bi-tangential plan, where both the tangential open beams were split. The planning target volume (PTV) coverage and the dose to the portion of muscles and axilla included in the standard tangential beams were compared. Results: PTV95 % of standard plan (91.9 ± 3.8) was not significantly different from single bi-tangential plan (91.8 ± 3.4); a small but significant (p < 0.01) decrease was observed with the double bi-tangential plan (90.1 ± 3.7). A marked dose reduction to the muscle was produced by the single bi-tangential plan around 30-40 Gy. The application of the double bi-tangential technique further reduced the volume receiving around 20 Gy, but did not markedly affect the higher doses. The dose to the axilla was reduced both in the single and the double bi-tangential plans. Conclusion: The single bi-tangential technique would have been able to reduce the dose to shoulder and axilla, without compromising target coverage. This simple technique is valuable for irradiation after axillary lymph node dissection or in patients without dissection due to negative or low-volume sentinel lymph node disease. (orig.)
Measurements of beam-ion confinement during tangential beam-driven instabilities in PBX [Princeton Beta Experiment

International Nuclear Information System (INIS)

Heidbrink, W.W.; Kaita, R.; Takahashi, H.; Gammel, G.; Hammett, G.W.; Kaye, S.

1987-01-01

During tangential injection of neutral beams into low density tokamak plasmas with β > 1% in the Princeton Beta Experiment (PBX), instabilities are observed that degrade the confinement of beam ions. Neutron, charge-exchange, and diamagnetic loop measurements are examined in order to identify the mechanism or mechanisms responsible for the beam-ion transport. The data suggest a resonant interaction between the instabilities and the parallel energetic beam ions. Evidence for some nonresonant transport also exists
The Effect of Turbulences Flow on a Gas-Liquid Mixing Process Downstream of a Curved Duct

Directory of Open Access Journals (Sweden)

Abdul Satar Jawad Mohammed

2018-02-01

Full Text Available An experimental investigation is carried out on the use of water injection on the humidification process of air with a steady flow that travels during the curved part of a duct with a constant cross section. The naturally generated turbulences will surely aid the mixing process between the injected water droplets and the air to enhance both the mass and heat transfer. The current investigation is regarded as a simulation of the inlet air cooling of the gas turbine which aims to specify the optimum atomizer position on the air cooling by the fogging technique. The experiments were carried out on a (50×50 cm wind tunnel with an average air velocity of (10 m/s. Experiments were conducted in a range of air to water flow ratio between 1000 and 2000, and an ambient temperature in a range of 30° to 50°C. At higher ambient temperature of 45.2oC (DBT, a temperature reduction of 26% and an increase in the relative humidity ratio of 2.13 were recorded at the flow ratio of 1000. Injecting water upward through the range of angles -25° to 75° showed less sensitivity to atomizer location regardless the radial position of the atomizer. This situation is most suitable for using atomizing array across the duct. The central location with tangential spray introduces the critical position for a single-point spray. Such position is promising the optimum atomizer place specified by a radii ratio of (r/rin=3 and tangential orientation to the direction of flow.
An accurate tangential force-displacement model for granular-flow simulations: Contacting spheres with plastic deformation, force-driven formulation

International Nuclear Information System (INIS)

Vu-Quoc, L.; Lesburg, L.; Zhang, X.

2004-01-01

An elasto-plastic frictional tangential force-displacement (TFD) model for spheres in contact for accurate and efficient granular-flow simulations is presented in this paper; the present TFD is consistent with the elasto-plastic normal force-displacement (NFD) model presented in [ASME Journal of Applied Mechanics 67 (2) (2000) 363; Proceedings of the Royal Society of London, Series A 455 (1991) (1999) 4013]. The proposed elasto-plastic frictional TFD model is accurate, and is validated against non-linear finite-element analyses involving plastic flows under both loading and unloading conditions. The novelty of the present TFD model lies in (i) the additive decomposition of the elasto-plastic contact area radius into an elastic part and a plastic part, (ii) the correction of the particles' radii at the contact point, and (iii) the correction of the particles' elastic moduli. The correction of the contact-area radius represents an effect of plastic deformation in colliding particles; the correction of the radius of curvature represents a permanent indentation after impact; the correction of the elastic moduli represents a softening of the material due to plastic flow. The construction of both the present elasto-plastic frictional TFD model and its consistent companion, the elasto-plastic NFD model, parallels the formalism of the continuum theory of elasto-plasticity. Both NFD and TFD models form a coherent set of force-displacement (FD) models not available hitherto for granular-flow simulations, and are consistent with the Hertz, Cattaneo, Mindlin, Deresiewicz contact mechanics theory. Together, these FD models will allow for efficient simulations of granular flows (or granular gases) involving a large number of particles
Development of flow injection analysis technique for uranium estimation

International Nuclear Information System (INIS)

Paranjape, A.H.; Pandit, S.S.; Shinde, S.S.; Ramanujam, A.; Dhumwad, R.K.

1991-01-01

Flow injection analysis is increasingly used as a process control analytical technique in many industries. It involves injection of the sample at a constant rate into a steady flowing stream of reagent and passing this mixture through a suitable detector. This paper describes the development of such a system for the analysis of uranium (VI) and (IV) and its gross gamma activity. It is amenable for on-line or automated off-line monitoring of uranium and its activity in process streams. The sample injection port is suitable for automated injection of radioactive samples. The performance of the system has been tested for the colorimetric response of U(VI) samples at 410 nm in the range of 35 to 360mg/ml in nitric acid medium using Metrohm 662 Photometer and a recorder as detector assembly. The precision of the method is found to be better than +/- 0.5%. This technique with certain modifications is used for the analysis of U(VI) in the range 0.1-3mg/ailq. by alcoholic thiocynate procedure within +/- 1.5% precision. Similarly the precision for the determination of U(IV) in the range 15-120 mg at 650 nm is found to be better than 5%. With NaI well-type detector in the flow line, the gross gamma counting of the solution under flow is found to be within a precision of +/- 5%. (author). 4 refs., 2 figs., 1 tab
Are Flow Injection-based Approaches Suitable for Automated Handling of Solid Samples?

DEFF Research Database (Denmark)

Miró, Manuel; Hansen, Elo Harald; Cerdà, Victor

Flow-based approaches were originally conceived for liquid-phase analysis, implying that constituents in solid samples generally had to be transferred into the liquid state, via appropriate batch pretreatment procedures, prior to analysis. Yet, in recent years, much effort has been focused...... electrolytic or aqueous leaching, on-line dialysis/microdialysis, in-line filtration, and pervaporation-based procedures have been successfully implemented in continuous flow/flow injection systems. In this communication, the new generation of flow analysis, including sequential injection, multicommutated flow.......g., soils, sediments, sludges), and thus, ascertaining the potential mobility, bioavailability and eventual impact of anthropogenic elements on biota [2]. In this context, the principles of sequential injection-microcolumn extraction (SI-MCE) for dynamic fractionation are explained in detail along...
Retro-review of flow injection analysis

DEFF Research Database (Denmark)

Ruzicka, Jaromir; Hansen, Elo Harald

2008-01-01

It is indeed unusual for authors to review their own monograph – J. Ruzicka, E.H. Hansen, Flow Injection Analysis, 2nd Edition, Wiley, Chichester, West Sussex, UK, 1988. – and even more so if the book was published 20 years ago. Yet such an exercise might yield a perspective on the progress of an...
Modified and reverse radiometric flow injection analysis

Energy Technology Data Exchange (ETDEWEB)

Myint, U; Ba, H; Khin, M M; Aung, K; Thida, [Yangon Univ. (Myanmar). Dept. of Chemistry; Toelgyessy, J [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Environmental Science

1994-06-01

Determination of [sup 137]Cs and [sup 60]Co by using modified and reverse radiometric flow injection analysis is described. Two component RFIA was also realized using [sup 60]Co and [sup 137]Cs radionuclides. (author) 2 refs.; 5 figs.
Pneumothorax in intensive-care patients: Ranking of tangential views

International Nuclear Information System (INIS)

Jantsch, H.; Winkler, M.; Pichler, W.; Mauritz, W.; Lechner, G.; Vienna Univ.

1990-01-01

In 55 intensive-care patients an additional tangential view of the chest was taken to demonstrate or exclude a pneumothorax in patients with sudden deterioration of gas exchange and negative ap-chest x-ray, if there was a suspicion of pneumothorax or a confirmed small pneumothorax in the ap-view. In 14 of 42 cases (33.3%) with negative or suspected ap-chest x-ray the tangential view revealed a pneumothorax. 6 of these 14 pneumothoraces were under tension. In 7 out of 11 patients (63.6%) with small pneumothorax, the tangential view showed additionally a tensionpneumothorax. (orig.) [de
Trends and perspectives of flow injection/sequential injection on-line sample-pretreatment schemes coupled to ETAAS

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald

2005-01-01

Flow injection (FI) analysis, the first generation of this technique, became in the 1990s supplemented by its second generation, sequential injection (SI), and most recently by the third generation (i.e.,Lab-on-Valve). The dominant role played by FI in automatic, on-line, sample pretreatments in ...
Charge Injection and Current Flow in Organic Light Emitting Diodes

Science.gov (United States)

Smith, D. L.; Davids, P. S.; Heller, C. M.; Crone, B. K.; Campbell, I. H.; Barashkov, N. N.; Ferraris, J. P.

1997-03-01

We present a comparison between device model calculations and current-voltage measurements for a series of organic LED structures. The Schottky energy barrier of an injecting contact is systematically varied by changing the metal used to form that contact. The current-voltage characteristics of the structures are described using a device model that considers charge injection, transport and space charge effects in the low mobility organic material. Charge injection into the organic material is controlled by the Schottky energy barrier of the metal/organic contact. For Schottky energy barriers greater than about 0.4 eV injection into the organic material is the principal limitation to current flow. In this regime the net injected charge density is relatively small, the electric field in the structure is nearly uniform, and space charge effects are not important. For smaller energy barriers relatively large charge densities are injected into the organic material and space charge effects become the dominant limit to current flow. The measured current-voltage characteristics are quantitatively described by the device model using Schottky barrier values independently determined by internal photoemission and electroabsorption measurements.
Experimental study on supersonic film cooling on the surface of a blunt body in hypersonic flow

International Nuclear Information System (INIS)

Fu Jia; Yi Shi-He; Wang Xiao-Hu; He Lin; Ge Yong

2014-01-01

The experimental study focuses on the heat flux on a double cone blunt body in the presence of tangential-slot supersonic injection into hypersonic flow. The tests are conducted in a contoured axisymmetric nozzle with Mach numbers of 7.3 and 8.1, and the total temperature is about 900 K. The injection Mach number is 3.2, and total temperature is 300 K. A constant voltage circuit is developed to supply the temperature detectors instead of the normally used constant current circuit. The schlieren photographs are presented additionally to visualize the flow and help analyze the pressure relationship between the cooling flow and the main flow. The dependence of the film-cooling effectiveness on flow parameters, i.e. the blow ratio, the convective Mach number, and the attack angle, is determined. A semi-empirical formula is tested by the present data, and is improved for a better correlation. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
The Co-axial Flow of Injectable Solid Hydrogels with Encapsulated Cells

Science.gov (United States)

Stewart, Brandon; Pochan, Darrin; Sathaye, Sameer

2013-03-01

Hydrogels are quickly becoming an important biomaterial that can be used for the safe, localized injection of cancer drugs, the injection of stem cells into areas of interest or other biological applications. Our peptides can be self-assembled in a syringe where they form a gel, sheared by injection and, once in the body, immediately reform a localized pocket of stiff gel. My project has been designed around looking at the possibility of having a co-axial strand, in which one gel can surround another. This co-axial flow can be used to change the physical properties of our gel during injection, such as stiffening our gel using hyaluronic acid or encapsulating cells in the gel and surrounding the gel with growth medium or other biological factors. Rheology on hyaluron stiffened gels and cells encapsulated in gels was performed for comparison to the results from co-axial flow. Confocal microscopy was used to examine the coaxial gels after flow and to determine how the co-axial nature of the gels is affected by the concentration of peptide.
Magnetic surfaces, particle orbits and neutral injection in conventional and ultimate torsatrons

International Nuclear Information System (INIS)

Anderson, D.T.; Derr, J.A.; Kruckewitt, T.; Shohet, J.L.; Rehker, S.; Tataronis, J.A.

1979-01-01

Capabilities in fully non-axisymmetric numerical methods have resulted in a parametric study of various conventional and ultimate torsatron configurations. No superbananas are found in torsatrons without local magnetic wells. Neutral injection calculations show that, if the vacuum magnetic surfaces are well defined, tangential injection is very efficient
Stopped-flow injection spectrophotometric method for determination of chlorate in soil

OpenAIRE

Jaroon Jakmunee

2008-01-01

A stopped-flow injection (FI) spectrophotometric procedure based on iodometric reaction for the determination of chlorate has been developed. Standard/sample was injected into a stream of potassium iodide solution and then merged with a stream of hydrochloric acid solution to produce triiodide. By stopping the flow while the sample zone is being in a mixing coil, a slow reaction of chlorate with iodide in acidic medium was promoted to proceed with minimal dispersion of the triiodide product z...
Tangential inlet supersonic separators: a novel apparatus for gas purification

DEFF Research Database (Denmark)

Wen, Chuang; Walther, Jens Honore; Yang, Yan

2016-01-01

A novel supersonic separator with a tangential inlet is designed to remove the condensable components from gas mixtures. The dynamic parameters of natural gas in the supersonic separation process are numerically calculated using the Reynolds stress turbulence model with the Peng-Robinson real gas...... be generated by the tangential inlet, and it increases to the maximum of 200 m/s at the nozzle throat due to decrease of the nozzle area of the converging part. The tangential velocity can maintain the value of about 160 m/s at the nozzle exit, and correspondingly generates the centrifugal acceleration of 3...
High-pressure size exclusion chromatography analysis of dissolved organic matter isolated by tangential-flow ultra filtration

Science.gov (United States)

Everett, C.R.; Chin, Y.-P.; Aiken, G.R.

1999-01-01

A 1,000-Dalton tangential-flow ultrafiltration (TFUF) membrane was used to isolate dissolved organic matter (DOM) from several freshwater environments. The TFUF unit used in this study was able to completely retain a polystyrene sulfonate 1,800-Dalton standard. Unaltered and TFUF-fractionated DOM molecular weights were assayed by high-pressure size exclusion chromatography (HPSEC). The weight-averaged molecular weights of the retentates were larger than those of the raw water samples, whereas the filtrates were all significantly smaller and approximately the same size or smaller than the manufacturer-specified pore size of the membrane. Moreover, at 280 nm the molar absorptivity of the DOM retained by the ultrafilter is significantly larger than the material in the filtrate. This observation suggests that most of the chromophoric components are associated with the higher molecular weight fraction of the DOM pool. Multivalent metals in the aqueous matrix also affected the molecular weights of the DOM molecules. Typically, proton-exchanged DOM retentates were smaller than untreated samples. This TFUF system appears to be an effective means of isolating aquatic DOM by size, but the ultimate size of the retentates may be affected by the presence of metals and by configurational properties unique to the DOM phase.

Sensitive flow-injection spectrophotometric analysis of bromopride

Science.gov (United States)

Lima, Liliane Spazzapam; Weinert, Patrícia Los; Pezza, Leonardo; Pezza, Helena Redigolo

2014-12-01

A flow injection spectrophotometric procedure employing merging zones is proposed for direct bromopride determination in pharmaceutical formulations and biological fluids. The proposed method is based on the reaction between bromopride and p-dimethylaminocinnamaldehyde (p-DAC) in acid medium, in the presence of sodium dodecyl sulfate (SDS), resulting in formation of a violet product (λmax = 565 nm). Experimental design methodologies were used to optimize the experimental conditions. The Beer-Lambert law was obeyed in a bromopride concentration range of 3.63 × 10-7 to 2.90 × 10-5 mol L-1, with a correlation coefficient (r) of 0.9999. The limits of detection and quantification were 1.07 × 10-7 and 3.57 × 10-7 mol L-1, respectively. The proposed method was successfully applied to the determination of bromopride in pharmaceuticals and human urine, and recoveries of the drug from these media were in the ranges 99.6-101.2% and 98.6-102.1%, respectively. This new flow injection procedure does not require any sample pretreatment steps.
Performance of a Compression-ignition Engine with a Precombustion Chamber Having High-Velocity Air Flow

Science.gov (United States)

Spanogle, J A; Moore, C S

1931-01-01

Presented here are the results of performance tests made with a single-cylinder, four stroke cycle, compression-ignition engine. These tests were made on a precombustion chamber type of cylinder head designed to have air velocity and tangential air flow in both the chamber and cylinder. The performance was investigated for variable load and engine speed, type of fuel spray, valve opening pressure, injection period and, for the spherical chamber, position of the injection spray relative to the air flow. The pressure variations between the pear-shaped precombustion chamber and the cylinder for motoring and full load conditions were determined with a Farnboro electric indicator. The combustion chamber designs tested gave good mixing of a single compact fuel spray with the air, but did not control the ensuing combustion sufficiently. Relative to each other, the velocity of air flow was too high, the spray dispersion by injection too great, and the metering effect of the cylinder head passage insufficient. The correct relation of these factors is of the utmost importance for engine performance.
Wide-angle ITER-prototype tangential infrared and visible viewing system for DIII-D

Energy Technology Data Exchange (ETDEWEB)

Lasnier, C. J., E-mail: lasnier@LLNL.gov; Allen, S. L.; Ellis, R. E.; Fenstermacher, M. E.; McLean, A. G.; Meyer, W. H.; Morris, K.; Seppala, L. G. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); Crabtree, K. [College of Optics, University of Arizona, Tucson, Arizona 85721 (United States); Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

2014-11-15

An imaging system with a wide-angle tangential view of the full poloidal cross-section of the tokamak in simultaneous infrared and visible light has been installed on DIII-D. The optical train includes three polished stainless steel mirrors in vacuum, which view the tokamak through an aperture in the first mirror, similar to the design concept proposed for ITER. A dichroic beam splitter outside the vacuum separates visible and infrared (IR) light. Spatial calibration is accomplished by warping a CAD-rendered image to align with landmarks in a data image. The IR camera provides scrape-off layer heat flux profile deposition features in diverted and inner-wall-limited plasmas, such as heat flux reduction in pumped radiative divertor shots. Demonstration of the system to date includes observation of fast-ion losses to the outer wall during neutral beam injection, and shows reduced peak wall heat loading with disruption mitigation by injection of a massive gas puff.
Flow Injection and Atomic Absorption Spectrometry (FI-AAS) -

DEFF Research Database (Denmark)

Hansen, Elo Harald

1996-01-01

One of the advantages of the flow injection (FI) concept is that it is compatible with virtually all detection techniques. Being a versatile vehicle for enhancing the performance of the individual detection devices, the most spectacular results have possibly been obtained in conjunction with atomic...... the point of sample injection/introduction to the point of detection. Hence, in FI-fAAS this feature allows not only to obtain improved repeatability but also improved accuracy, and because the wash to sample ratio is high it permits the handling of samples with elevated salt contents - which...
Flow Injection/Sequential Injection Analysis Systems: Potential Use as Tools for Rapid Liver Diseases Biomarker Study

Directory of Open Access Journals (Sweden)

Supaporn Kradtap Hartwell

2012-01-01

Full Text Available Flow injection/sequential injection analysis (FIA/SIA systems are suitable for carrying out automatic wet chemical/biochemical reactions with reduced volume and time consumption. Various parts of the system such as pump, valve, and reactor may be built or adapted from available materials. Therefore the systems can be at lower cost as compared to other instrumentation-based analysis systems. Their applications for determination of biomarkers for liver diseases have been demonstrated in various formats of operation but only a few and limited types of biomarkers have been used as model analytes. This paper summarizes these applications for different types of reactions as a guide for using flow-based systems in more biomarker and/or multibiomarker studies.
Interaction of Liquid Film Flow of Direct Vessel Injection Under the Cross Directional Gas Flow

Energy Technology Data Exchange (ETDEWEB)

Kim, Han-sol; Lee, Jae-young [Handong Global University, Pohang (Korea, Republic of); Euh, Dong-Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

In order to obtain a proper scaling law of the flow, local information of the flow was investigated experimentally and also numerically. A series of experiments were conducted in the 1/20 modified linear scaled plate type test rig to analyze a liquid film from ECC water injection through the DVI nozzle to the downcomer wall. The present study investigates liquid film flow generated in a downcomer of direct vessel injection (DVI) system which is employed as an emergency core cooling (ECC) system during a loss of coolant accident in the Korea nuclear power plant APR1400. During the late reflooding, complicated multi-phase flow phenomena including the wavy film flow, film breakup, entrainment, liquid film shift due to interfacial drag and gas jet impingement occur. A confocal chromatic sensor was used to measure the local instantaneous liquid film thickness and a hydraulic jump in the film flow and boundaries of the film flow. It was found that CFD analysis results without surface tension model showed some difference with the data in surface tension dominated flow region. For the interaction between a liquid film and gas shear flow, CFD results make a good agreement with the real liquid film dynamics in the case of low film Reynolds number or low Weber number flow. In the 1/20 scaled plate type experiment and simulation, the deformed spreading profile results seem to accord with each other at the relatively low We and Re regime.
Numerical investigation on the flow, combustion, and NOX emission characteristics in a 660 MWe tangential firing ultra-supercritical boiler

Directory of Open Access Journals (Sweden)

Wenjing Sun

2016-02-01

Full Text Available A three-dimensional numerical simulation was carried out to study the pulverized-coal combustion process in a tangentially fired ultra-supercritical boiler. The realizable k-ε model for gas coupled with discrete phase model for coal particles, P-1 radiation model for radiation, two-competing-rates model for devolatilization, and kinetics/diffusion-limited model for combustion process are considered. The characteristics of the flow field, particle motion, temperature distribution, species components, and NOx emissions were numerically investigated. The good agreement of the measurements and predictions implies that the applied simulation models are appropriate for modeling commercial-scale coal boilers. It is found that an ideal turbulent flow and particle trajectory can be observed in this unconventional pulverized-coal furnace. With the application of over-fire air and additional air, lean-oxygen combustion takes place near the burner sets region and higher temperature at furnace exit is acquired for better heat transfer. Within the limits of secondary air, more steady combustion process is achieved as well as the reduction of NOx. Furthermore, the influences of the secondary air, over-fire air, and additional air on the NOx emissions are obtained. The numerical results reveal that NOx formation attenuates with the decrease in the secondary air ratio (γ2nd and the ratio of the additional air to the over-fire air (γAA/γOFA was within the limits.
PIV measurements of the turbulence integral length scale on cold combustion flow field of tangential firing boiler

Energy Technology Data Exchange (ETDEWEB)

Wu, Wen-fei; Xie, Jing-xing; Gong, Zhi-jun; Li, Bao-wei [Inner Mongolia Univ. of Science and Technology, Baotou (China). Inner Mongolia Key Lab. for Utilization of Bayan Obo Multi-Metallic Resources: Elected State Key Lab.

2013-07-01

The process of the pulverized coal combustion in tangential firing boiler has prominent significance on improving boiler operation efficiency and reducing NO{sub X} emission. This paper aims at researching complex turbulent vortex coherent structure formed by the four corners jets in the burner zone, a cold experimental model of tangential firing boiler has been built. And by employing spatial correlation analysis method and PIV (Particle Image Velocimetry) technique, the law of Vortex scale distribution on the three typical horizontal layers of the model based on the turbulent Integral Length Scale (ILS) has been researched. According to the correlation analysis of ILS and the temporal average velocity, it can be seen that the turbulent vortex scale distribution in the burner zone of the model is affected by both jet velocity and the position of wind layers, and is not linear with the variation of jet velocity. The vortex scale distribution of the upper primary air is significantly different from the others. Therefore, studying the ILS of turbulent vortex integral scale is instructive to high efficiency cleaning combustion of pulverized coal in theory.
Radiometric flow injection analysis with an ASIA (Ismatec) analyzer

Energy Technology Data Exchange (ETDEWEB)

Myint, U; Win, N; San, K; Han, B; Myoe, K M [Yangon Univ. (Myanmar). Dept. of Chemistry; Toelgyessy, J [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Environmental Science

1994-07-01

Radiometric Flow Injection Analysis of a radioactive ([sup 131]I) sample is described. For analysis an ASIA (Ismatec) analyzer with a NaI(Tl) scintillation detector was used. (author) 5 refs.; 3 figs.
Cross-flow analysis of injection wells in a multilayered reservoir

Directory of Open Access Journals (Sweden)

Mohammadreza Jalali

2016-09-01

Natural and forced cross-flow is modeled for some injection wells in an oil reservoir located at North Sea. The solution uses a transient implicit finite difference approach for multiple sand layers with different permeabilities separated by impermeable shale layers. Natural and forced cross-flow rates for each reservoir layer during shut-in are calculated and compared with different production logging tool (PLT measurements. It appears that forced cross-flow is usually more prolonged and subject to a higher flow rate when compared with natural cross-flow, and is thus worthy of more detailed analysis.
The effects of arbitrary injection angle and flow conditions on venturi-jet mixer

Directory of Open Access Journals (Sweden)

Sundararaj S.

2012-01-01

Full Text Available This paper describes the effect of jet injection angle, cross flow Reynolds number and velocity ratio on entrainment and mixing of jet with incompressible cross flow in venturi-jet mixer. Five different jet injection angles 45o, 60o, 90o, 125o, 135o are tested to evaluate the entrainment of jet and mixing performances of the mixer. Tracer concentration along the downstream of the jet injection, cross flow velocity, jet velocity and pressure drop across the mixer are determined experimentally to characterize the mixing performance of the mixer. The experiments show that the performance of a venturi-jet-mixer substantially improves at high injection angle and can be augmented still by increasing velocity ratio. The jet deflects much and penetrates less in the cross flow as the cross flow Reynolds number is increased. The effect could contribute substantially to the better mixing index with moderate pressure drop. Normalized jet profile, concentration decay, jet velocity profile are computed from equations of conservation of mass, momentum and concentration written in natural co-ordinate systems. The comparison between the experimental and numerical results confirms the accuracy of the simulations. Correlations for jet trajectory and entrainment ratio of the mixer are obtained by multivariate-linear regression analysis using power law.
Flow regime analysis for fluid injection into a confined aquifer: implications for CO2 sequestration

Science.gov (United States)

Guo, B.; Zheng, Z.; Celia, M. A.; Stone, H.

2015-12-01

Carbon dioxide injection into a confined saline aquifer may be modeled as an axisymmetric two-phase flow problem. Assuming the two fluids segregate in the vertical direction due to strong buoyancy, and neglecting capillary pressure and miscibility, the lubrication approximation leads to a nonlinear advection-diffusion equation that describes the evolution of the sharp fluid-fluid interface. The flow behaviors in the system are controlled by two dimensionless groups: M, the viscosity ratio of the displaced fluid relative to injected fluid, and Γ , the gravity number, which represents the relative importance of buoyancy and fluid injection. Four different analytical solutions can be derived as the asymptotic approximations, representing specific values of the parameter pairs. The four solutions correspond to: (1) Γ 1; and (4) Γ >> 1, any M values. The first two of these solutions are new, while the third corresponds to the solution of Nordbotten and Celia (2006) for confined injections and the fourth corresponds to the solution of (Lyle et al., 2005) for gravity currents in an unconfined aquifer. Overall, the various axisymmetric flows can be summarized in a Γ-M regime diagram with five distinct dynamic behaviors including the four asymptotic regimes and an intermediate regime (Fig. 1). Data from a number of CO2 injection sites around the world can be used to compute the two dimensionless groups Γ and M associated with each injection. When plotted on the regime diagram, these values show the flow behavior for each injection and how the values vary from site to site. For all the CO2 injections, M is always larger than 1, while Γ can range from 0.01 up to 100. The pairs of (Γ, M) with lower Γ values correspond to solution (3), while the ones with higher Γ values can move up to the intermediate regime and the flow regime for solution (4). The higher values of Γ correspond to pilot-scale injections with low injection rates; most industrial-scale injection
Injection and swirl driven flowfields in solid and liquid rocket motors

Science.gov (United States)

Vyas, Anand B.

In this work, we seek approximate analytical solutions to describe the bulk flow motion in certain types of solid and liquid rocket motors. In the case of an idealized solid rocket motor, a cylindrical double base propellant grain with steady regression rate is considered. The well known inviscid profile determined by Culick is extended here to include the effects of viscosity and steady grain regression. The approximate analytical solution for the cold flow is obtained from similarity principles, perturbation methods and the method of variation of parameters. The velocity, vorticity, pressure gradient and the shear stress distributions are determined and interpreted for different rates of wall regression and injection Reynolds number. The liquid propellant rocket engine considered here is based on a novel design that gives rise to a cyclonic flow. The resulting bidirectional motion is triggered by the tangential injection of an oxidizer just upstream of the chamber nozzle. Velocity, vorticity and pressure gradient distributions are determined for the bulk gas dynamics using a non-reactive inviscid model. Viscous corrections are then incorporated to explain the formation of a forced vortex near the core. Our results compare favorably with numerical simulations and experimental measurements obtained by other researchers. They also indicate that the bidirectional vortex in a cylindrical chamber is a physical solution of the Euler equations. In closing, we investigate the possibility of multi-directional flow behavior as predicted by Euler's equation and as reported recently in laboratory experiments.
Determination of Optimal Flow Paths for Safety Injection According to Accident Conditions

Energy Technology Data Exchange (ETDEWEB)

Yoo, Kwae Hwan; Kim, Ju Hyun; Kim, Dong Yeong; Na, Man Gyun [Chosun Univ., Gwangju (Korea, Republic of); Hur, Seop; Kim, Changhwoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

In case severe accidents happen, major safety parameters of nuclear reactors are rapidly changed. Therefore, operators are unable to respond appropriately. This situation causes the human error of operators that led to serious accidents at Chernobyl. In this study, we aimed to develop an algorithm that can be used to select the optimal flow path for cold shutdown in serious accidents, and to recover an NPP quickly and efficiently from the severe accidents. In order to select the optimal flow path, we applied a Dijkstra algorithm. The Dijkstra algorithm is used to find the path of minimum total length between two given nodes and needs a weight (or length) matrix. In this study, the weight between nodes was calculated from frictional and minor losses inside pipes. That is, the optimal flow path is found so that the pressure drop between a starting node (water source) and a destination node (position that cooling water is injected) is minimized. In case a severe accident has happened, if we inject cooling water through the optimized flow path, then the nuclear reactor will be safely and effectively returned into the cold shutdown state. In this study, we have analyzed the optimal flow paths for safety injection as a preliminary study for developing an accident recovery system. After analyzing the optimal flow path using the Dijkstra algorithm, and the optimal flow paths were selected by calculating the head loss according to path conditions.
Assessment of Set-up Accuracy in Tangential Breast Treatment Using Electronic Portal Imaging Device

International Nuclear Information System (INIS)

Lee, Byung Koo; Kang, Soo Man

2012-01-01

The aim of this study was to investigate the setup accuracy for tangential breast treatment patients using electronic portal image and 2-D reconstruction image Twenty two patients undergoing tangential breast treatment. To explore the setup accuracy, distances between chosen landmarks were taken as reference parameters. The difference between measured reference parameters on simulation films and electronic portal images (EPIs) was calculated as the setup error. A total of 22 simulation films and 110 EPIs were evaluated. In the tangential fields, the calculated reference parameters were the central lung distance (CLD), central soft-tissue distance (CSTD), and above lung distance (ALD), below lung distance (BLD). In the medial tangential field, the average difference values for these parameters were 1.0, -6.4, -2.1 and 2.0, respectively; and the values were 1.5, 2.3, 4.1 and 1.1, respectively. In the lateral tangential field, the average difference values for these parameters were -1.5, -4.3, -2.7 and -1.3, respectively; and the values were 3.3, 2.1, 2.9 and 2.5, respectively. CLD, CSTD, ALD and BLD in the tangential fields are easily identifiable and are helpful for detecting setup errors using EPIs in patients undergoing tangential breast radiotherapy treatment.
Assessment of Set-up Accuracy in Tangential Breast Treatment Using Electronic Portal Imaging Device

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Koo [Dept. of Radiation Oncology, Korea University Anam Hospital, Seoul (Korea, Republic of); Kang, Soo Man [Dept. of Radiation Oncology, Korea University Gospel Hospital, Seoul (Korea, Republic of)

2012-09-15

The aim of this study was to investigate the setup accuracy for tangential breast treatment patients using electronic portal image and 2-D reconstruction image Twenty two patients undergoing tangential breast treatment. To explore the setup accuracy, distances between chosen landmarks were taken as reference parameters. The difference between measured reference parameters on simulation films and electronic portal images (EPIs) was calculated as the setup error. A total of 22 simulation films and 110 EPIs were evaluated. In the tangential fields, the calculated reference parameters were the central lung distance (CLD), central soft-tissue distance (CSTD), and above lung distance (ALD), below lung distance (BLD). In the medial tangential field, the average difference values for these parameters were 1.0, -6.4, -2.1 and 2.0, respectively; and the values were 1.5, 2.3, 4.1 and 1.1, respectively. In the lateral tangential field, the average difference values for these parameters were -1.5, -4.3, -2.7 and -1.3, respectively; and the values were 3.3, 2.1, 2.9 and 2.5, respectively. CLD, CSTD, ALD and BLD in the tangential fields are easily identifiable and are helpful for detecting setup errors using EPIs in patients undergoing tangential breast radiotherapy treatment.
A Semi-Analytical Method for Rapid Estimation of Near-Well Saturation, Temperature, Pressure and Stress in Non-Isothermal CO2 Injection

Science.gov (United States)

LaForce, T.; Ennis-King, J.; Paterson, L.

2015-12-01

Reservoir cooling near the wellbore is expected when fluids are injected into a reservoir or aquifer in CO2 storage, enhanced oil or gas recovery, enhanced geothermal systems, and water injection for disposal. Ignoring thermal effects near the well can lead to under-prediction of changes in reservoir pressure and stress due to competition between increased pressure and contraction of the rock in the cooled near-well region. In this work a previously developed semi-analytical model for immiscible, nonisothermal fluid injection is generalised to include partitioning of components between two phases. Advection-dominated radial flow is assumed so that the coupled two-phase flow and thermal conservation laws can be solved analytically. The temperature and saturation profiles are used to find the increase in reservoir pressure, tangential, and radial stress near the wellbore in a semi-analytical, forward-coupled model. Saturation, temperature, pressure, and stress profiles are found for parameters representative of several CO2 storage demonstration projects around the world. General results on maximum injection rates vs depth for common reservoir parameters are also presented. Prior to drilling an injection well there is often little information about the properties that will determine the injection rate that can be achieved without exceeding fracture pressure, yet injection rate and pressure are key parameters in well design and placement decisions. Analytical solutions to simplified models such as these can quickly provide order of magnitude estimates for flow and stress near the well based on a range of likely parameters.
Flow rate dependent extra-column variance from injection in capillary liquid chromatography.

Science.gov (United States)

Aggarwal, Pankaj; Liu, Kun; Sharma, Sonika; Lawson, John S; Dennis Tolley, H; Lee, Milton L

2015-02-06

Efficiency and resolution in capillary liquid chromatography (LC) can be significantly affected by extra-column band broadening, especially for isocratic separations. This is particularly a concern in evaluating column bed structure using non-retained test compounds. The band broadening due to an injector supplied with a commercially available capillary LC system was characterized from experimental measurements. The extra-column variance from the injection valve was found to have an extra-column contribution independent of the injection volume, showing an exponential dependence on flow rate. The overall extra-column variance from the injection valve was found to vary from 34 to 23 nL. A new mathematical model was derived that explains this exponential contribution of extra-column variance on chromatographic performance. The chromatographic efficiency was compromised by ∼130% for a non-retained analyte because of injection valve dead volume. The measured chromatographic efficiency was greatly improved when a new nano-flow pumping system with integrated injection valve was used. Copyright © 2014 Elsevier B.V. All rights reserved.
Re-injection feasibility study of fracturing flow-back fluid in shale gas mining

Science.gov (United States)

Kang, Dingyu; Xue, Chen; Chen, Xinjian; Du, Jiajia; Shi, Shengwei; Qu, Chengtun; Yu, Tao

2018-02-01

Fracturing flow-back fluid in shale gas mining is usually treated by re-injecting into formation. After treatment, the fracturing flow-back fluid is injected back into the formation. In order to ensure that it will not cause too much damage to the bottom layer, feasibility evaluations of re-injection of two kinds of fracturing fluid with different salinity were researched. The experimental research of the compatibility of mixed water samples based on the static simulation method was conducted. Through the analysis of ion concentration, the amount of scale buildup and clay swelling rate, the feasibility of re-injection of different fracturing fluid were studied. The result shows that the swelling of the clay expansion rate of treated fracturing fluid is lower than the mixed water of treated fracturing fluid and the distilled water, indicating that in terms of clay expansion rate, the treated fracturing flow-back fluid is better than that of water injection after re-injection. In the compatibility test, the maximum amount of fouling in the Yangzhou oilfield is 12mg/L, and the maximum value of calcium loss rate is 1.47%, indicating that the compatibility is good. For the fracturing fluid with high salinity in the Yanchang oilfield, the maximum amount of scaling is 72mg/L, and the maximum calcium loss rate is 3.50%, indicating that the compatibility is better.
Rapid dual-injection single-scan 13N-ammonia PET for quantification of rest and stress myocardial blood flows

International Nuclear Information System (INIS)

Rust, T C; DiBella, E V R; McGann, C J; Christian, P E; Hoffman, J M; Kadrmas, D J

2006-01-01

Quantification of myocardial blood flows at rest and stress using 13 N-ammonia PET is an established method; however, current techniques require a waiting period of about 1 h between scans. The objective of this study was to test a rapid dual-injection single-scan approach, where 13 N-ammonia injections are administered 10 min apart during rest and adenosine stress. Dynamic PET data were acquired in six human subjects using imaging protocols that provided separate single-injection scans as gold standards. Rest and stress data were combined to emulate rapid dual-injection data so that the underlying activity from each injection was known exactly. Regional blood flow estimates were computed from the dual-injection data using two methods: background subtraction and combined modelling. The rapid dual-injection approach provided blood flow estimates very similar to the conventional single-injection standards. Rest blood flow estimates were affected very little by the dual-injection approach, and stress estimates correlated strongly with separate single-injection values (r = 0.998, mean absolute difference = 0.06 ml min -1 g -1 ). An actual rapid dual-injection scan was successfully acquired in one subject and further demonstrates feasibility of the method. This study with a limited dataset demonstrates that blood flow quantification can be obtained in only 20 min by the rapid dual-injection approach with accuracy similar to that of conventional separate rest and stress scans. The rapid dual-injection approach merits further development and additional evaluation for potential clinical use

Vibrotactile Compliance Feedback for Tangential Force Interaction.

Science.gov (United States)

Heo, Seongkook; Lee, Geehyuk

2017-01-01

This paper presents a method to generate a haptic illusion of compliance using a vibrotactile actuator when a tangential force is applied to a rigid surface. The novel method builds on a conceptual compliance model where a physical object moves on a textured surface in response to a tangential force. The method plays vibration patterns simulating friction-induced vibrations as an applied tangential force changes. We built a prototype consisting of a two-dimensional tangential force sensor and a surface transducer to test the effectiveness of the model. Participants in user experiments with the prototype perceived the rigid surface of the prototype as a moving, rubber-like plate. The main findings of the experiments are: 1) the perceived stiffness of a simulated material can be controlled by controlling the force-playback transfer function, 2) its perceptual properties such as softness and pleasantness can be controlled by changing friction grain parameters, and 3) the use of the vibrotactile compliance feedback reduces participants' workload including physical demand and frustration while performing a force repetition task.
Flow Injection Analysis: A Revolution in Modern Analytical Chemistry

DEFF Research Database (Denmark)

Hansen, Elo Harald

1996-01-01

A review is made of the fundamentals of Flow Injection Analysis (FIA), and the versatility and applicability of this analytical concept is demonstrated by a series of examples, comprizing the use of different types of FIA-manifolds and various detection devices (optical and electrochemical...
Screen-printed sensor for batch and flow injection potentiometric chromium(VI) monitoring

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Moreno, Raul A.; Gismera, M.J.; Sevilla, M.T.; Procopio, Jesus R. [Facultad de Ciencias, Universidad Autonoma de Madrid, Departamento de Quimica Analitica y Analisis Instrumental, Madrid (Spain)

2010-05-15

A disposable screen-printed electrode was designed and evaluated for direct detection of chromium(VI) in batch and flow analysis. The carbon screen-printed electrode was modified with a graphite-epoxy composite. The optimal graphite-epoxy matrix contains 37.5% graphite powder, 12.5% diphenylcarbohydrazide, a selective compound for chromium(VI), and 50% epoxy resin. The principal analytical parameters of the potentiometric response in batch and flow analysis were optimized and calculated. The screen-printed sensor exhibits a response time of 20 {+-} 1 s. In flow analysis, the analytical frequency of sampling is 70 injections per hour using 0.1 M NaNO{sub 3} solution at pH 3 as the carrier, a flow rate of 2.5 mL.min{sup -1}, and an injection sample volume of 0.50 mL. The sensor shows potentiometric responses that are very selective for chromium(VI) ions and optimal detection limits in both static mode (2.1 x 10{sup -7} M) and online analysis (9.4 x 10{sup -7} M). The disposable potentiometric sensor was employed to determine toxicity levels of chromium(VI) in mineral, tap, and river waters by flow-injection potentiometry and batch potentiometry. Chromium(VI) determination was also carried out with successful results in leachates from municipal solid waste landfills. (orig.)
Enhancement of melting heat transfer of ice slurries by an injection flow in a rectangular cross sectional horizontal duct

International Nuclear Information System (INIS)

Fujii, Kota; Yamada, Masahiko

2013-01-01

Ice slurries are now commonly used as cold thermal storage materials, and have the potential to be applied to other engineering fields such as quenching metals to control properties, emergency cooling systems, and preservation of food and biomaterials at low temperatures. Although ice slurries have been widely utilized because of their high thermal storage densities, previous studies have revealed that the latent heat of ice particles is not completely released on melting because of insufficient contact between the ice particles and a heated surface. In this study, an injection flow that was bifurcated from the main flow of an ice slurry was employed to promote melting heat transfer of ice particles on a horizontal heated surface. The effects of injection angle and injection flow rate on local heat transfer coefficients and heat transfer coefficient ratios were determined experimentally. The results show that from two to three times higher heat transfer coefficients can be obtained by using large injection flow rates and injection angles. However, low injection angles improved the utilization rate of the latent heat of ice near the injection point by approximately a factor of two compared to that without injection. -- Highlights: • Melting of ice slurries were enhanced by the injection under constant total flow rate. • Contribution of ice particles and their latent heat to heat transfer was investigated. • Effect of velocity ratio of injection to that of main flow was examined. • Effect of the angle of injection flow to the main flow was also examined. • Appropriate conditions for the use of latent heat of ice and heat transfer did not coincide
Liquid sprays and flow studies in the direct-injection diesel engine under motored conditions

Science.gov (United States)

Nguyen, Hung Lee; Carpenter, Mark H.; Ramos, Juan I.; Schock, Harold J.; Stegeman, James D.

1988-01-01

A two dimensional, implicit finite difference method of the control volume variety, a two equation model of turbulence, and a discrete droplet model were used to study the flow field, turbulence levels, fuel penetration, vaporization, and mixing in diesel engine environments. The model was also used to study the effects of engine speed, injection angle, spray cone angle, droplet distribution, and intake swirl angle on the flow field, spray penetration and vaporization, and turbulence in motored two-stroke diesel engines. It is shown that there are optimum conditions for injection, which depend on droplet distribution, swirl, spray cone angle, and injection angle. The optimum conditions result in good spray penetration and vaporization and in good fuel mixing. The calculation presented clearly indicates that internal combustion engine models can be used to assess, at least qualitatively, the effects of injection characteristics and engine operating conditions on the flow field and on the spray penetration and vaporization in diesel engines.
Numerical investigation of the air injection effect on the cavitating flow in Francis hydro turbine

Science.gov (United States)

Chirkov, D. V.; Shcherbakov, P. K.; Cherny, S. G.; Skorospelov, V. A.; Turuk, P. A.

2017-09-01

At full and over load operating points, some Francis turbines experience strong self-excited pressure and power oscillations. These oscillations are occuring due to the hydrodynamic instability of the cavitating fluid flow. In many cases, the amplitude of such pulsations may be reduced substantially during the turbine operation by the air injection/ admission below the runner. Such an effect is investigated numerically in the present work. To this end, the hybrid one-three-dimensional model of the flow of the mixture "liquid-vapor" in the duct of a hydroelectric power station, which was proposed previously by the present authors, is augmented by the second gaseous component — the noncondensable air. The boundary conditions and the numerical method for solving the equations of the model are described. To check the accuracy of computing the interface "liquid-gas", the numerical method was applied at first for solving the dam break problem. The algorithm was then used for modeling the flow in a hydraulic turbine with air injection below the runner. It is shown that with increasing flow rate of the injected air, the amplitude of pressure pulsations decreases. The mechanism of the flow structure alteration in the draft tube cone has been elucidated, which leads to flow stabilization at air injection.
Variation of Drying Strains between Tangential and Radial Directions in Asian White Birch

Directory of Open Access Journals (Sweden)

Zongying Fu

2016-03-01

Full Text Available In this study, wood disks of 30 mm in thickness cut from white birch (Betula platyphylla Suk logs were dried at a constant temperature (40 °C. The drying strains including practical shrinkage strain, elastic strain, viscoelastic creep strain and mechano-sorptive creep were measured both tangentially and radially. The effects of moisture content and radial position on each strain were also discussed qualitatively. Overall, the difference of the practical shrinkage strain between the tangential and radial directions was proportional to the distance from the pith. The tangential elastic strain and viscoelastic creep strain were higher than these strains in a radial direction, and they all decreased with the decrease of moisture content. Additionally, there were opposite mechano-sorptive creep between tangential and radial directions.
Flow injection analysis using carbon film resistor electrodes for amperometric determination of ambroxol.

Science.gov (United States)

Felix, Fabiana S; Brett, Christopher M A; Angnes, Lúcio

2008-06-30

Flow injection analysis (FIA) using a carbon film sensor for amperometric detection was explored for ambroxol analysis in pharmaceutical formulations. The specially designed flow cell designed in the lab generated sharp and reproducible current peaks, with a wide linear dynamic range from 5x10(-7) to 3.5x10(-4) mol L(-1), in 0.1 mol L(-1) sulfuric acid electrolyte, as well as high sensitivity, 0.110 Amol(-1) L cm(-2) at the optimized flow rate. A detection limit of 7.6x10(-8) mol L(-1) and a sampling frequency of 50 determinations per hour were achieved, employing injected volumes of 100 microL and a flow rate of 2.0 mL min(-1). The repeatability, expressed as R.S.D. for successive and alternated injections of 6.0x10(-6) and 6.0x10(-5) mol L(-1) ambroxol solutions, was 3.0 and 1.5%, respectively, without any noticeable memory effect between injections. The proposed method was applied to the analysis of ambroxol in pharmaceutical samples and the results obtained were compared with UV spectrophotometric and acid-base titrimetric methods. Good agreement between the results utilizing the three methods and the labeled values was achieved, corroborating the good performance of the proposed electrochemical methodology for ambroxol analysis.
Numerical Simulation of Polymer Injection in Turbulent Flow Past a Circular Cylinder

KAUST Repository

Richter, David; Shaqfeh, Eric S. G.; Iaccarino, Gianluca

2011-01-01

Using a code developed to compute high Reynolds number viscoelastic flows, polymer injection from the upstream stagnation point of a circular cylinder is modeled at Re = 3900. Polymer stresses are represented using the FENE-P constitutive equations. By increasing polymer injection rates within realistic ranges, significant near wake stabilization is observed. Rather than a turbulent detached shear layer giving way to a chaotic primary vortex (as seen in Newtonian flows at high Re), a much more coherent primary vortex is shed, which possesses an increased core pressure as well as a reduced level of turbulent energy. © 2011 American Society of Mechanical Engineers.
Detailed evaluation of the natural circulation mass flow rate of water propelled by using an air injection

International Nuclear Information System (INIS)

Park, Rae-Joon; Ha, Kwang-Soon; Kim, Jae-Cheol; Hong, Seong-Wan; Kim, Sang-Baik

2008-01-01

One-dimensional (1D) air-water two-phase natural circulation flow in the thermohydraulic evaluation of reactor cooling mechanism by external self-induced flow - one-dimensional' (THERMES-1D) experiment has been verified and evaluated by using the RELAP5/MOD3 computer code. Experimental results on the 1D natural circulation mass flow rate of water propelled by using an air injection have been evaluated in detail. The RELAP5 results have shown that an increase in the air injection rate to 50% of the total heat flux leads to an increase in the water circulation mass flow rate. However, an increase in the air injection rate from 50 to 100% does not affect the water circulation mass flow rate, because of the inlet area condition. As the height increases in the air injection part, the void fraction increases. However, the void fraction in the upper part of the air injector maintains a constant value. An increase in the air injection mass flow rate leads to an increase in the local void fraction, but it has no influence on the local pressure. An increase in the coolant inlet area leads to an increase in the water circulation mass flow rate. However, the water outlet area does not have an influence on the water circulation mass flow rate. As the coolant outlet moves to a lower position, the water circulation mass flow rate decreases. (author)
Decompositions of injection patterns for nodal flow allocation in renewable electricity networks

Science.gov (United States)

Schäfer, Mirko; Tranberg, Bo; Hempel, Sabrina; Schramm, Stefan; Greiner, Martin

2017-08-01

The large-scale integration of fluctuating renewable power generation represents a challenge to the technical and economical design of a sustainable future electricity system. In this context, the increasing significance of long-range power transmission calls for innovative methods to understand the emerging complex flow patterns and to integrate price signals about the respective infrastructure needs into the energy market design. We introduce a decomposition method of injection patterns. Contrary to standard flow tracing approaches, it provides nodal allocations of link flows and costs in electricity networks by decomposing the network injection pattern into market-inspired elementary import/export building blocks. We apply the new approach to a simplified data-driven model of a European electricity grid with a high share of renewable wind and solar power generation.
Tangential flow ultrafiltration for detection of white spot syndrome virus (WSSV) in shrimp pond water.

Science.gov (United States)

Alavandi, S V; Ananda Bharathi, R; Satheesh Kumar, S; Dineshkumar, N; Saravanakumar, C; Joseph Sahaya Rajan, J

2015-06-15

Water represents the most important component in the white spot syndrome virus (WSSV) transmission pathway in aquaculture, yet there is very little information. Detection of viruses in water is a challenge, since their counts will often be too low to be detected by available methods such as polymerase chain reaction (PCR). In order to overcome this difficulty, viruses in water have to be concentrated from large volumes of water prior to detection. In this study, a total of 19 water samples from aquaculture ecosystem comprising 3 creeks, 10 shrimp culture ponds, 3 shrimp broodstock tanks and 2 larval rearing tanks of shrimp hatcheries and a sample from a hatchery effluent treatment tank were subjected to concentration of viruses by ultrafiltration (UF) using tangential flow filtration (TFF). Twenty to 100l of water from these sources was concentrated to a final volume of 100mL (200-1000 fold). The efficiency of recovery of WSSV by TFF ranged from 7.5 to 89.61%. WSSV could be successfully detected by PCR in the viral concentrates obtained from water samples of three shrimp culture ponds, one each of the shrimp broodstock tank, larval rearing tank, and the shrimp hatchery effluent treatment tank with WSSV copy numbers ranging from 6 to 157mL(-1) by quantitative real time PCR. The ultrafiltration virus concentration technique enables efficient detection of shrimp viral pathogens in water from aquaculture facilities. It could be used as an important tool to understand the efficacy of biosecurity protocols adopted in the aquaculture facility and to carry out epidemiological investigations of aquatic viral pathogens. Copyright © 2015 Elsevier B.V. All rights reserved.
Gaseous slip flow analysis of a micromachined flow sensor for ultra small flow applications

OpenAIRE

Jang, Jaesung; Wereley, Steven

2007-01-01

The velocity slip of a fluid at a wall is one of the most typical phenomena in microscale gas flows. This paper presents a flow analysis considering the velocity slip in a capacitive micro gas flow sensor based on pressure difference measurements along a microchannel. The tangential momentum accommodation coefficient (TMAC) measurements of a particular channel wall in planar microchannels will be presented while the previous micro gas flow studies have been based on the same TMACs on both wal...
Modeling and flow analysis of pure nylon polymer for injection molding process

International Nuclear Information System (INIS)

Nuruzzaman, D M; Kusaseh, N; Basri, S; Hamedon, Z; Oumer, A N

2016-01-01

In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured. (paper)
Modeling and flow analysis of pure nylon polymer for injection molding process

Science.gov (United States)

Nuruzzaman, D. M.; Kusaseh, N.; Basri, S.; Oumer, A. N.; Hamedon, Z.

2016-02-01

In the production of complex plastic parts, injection molding is one of the most popular industrial processes. This paper addresses the modeling and analysis of the flow process of the nylon (polyamide) polymer for injection molding process. To determine the best molding conditions, a series of simulations are carried out using Autodesk Moldflow Insight software and the processing parameters are adjusted. This mold filling commercial software simulates the cavity filling pattern along with temperature and pressure distributions in the mold cavity. In the modeling, during the plastics flow inside the mold cavity, different flow parameters such as fill time, pressure, temperature, shear rate and warp at different locations in the cavity are analyzed. Overall, this Moldflow is able to perform a relatively sophisticated analysis of the flow process of pure nylon. Thus the prediction of the filling of a mold cavity is very important and it becomes useful before a nylon plastic part to be manufactured.
Study of process parameters on two phase flow agitated by top blowing lance injection into a bath

Energy Technology Data Exchange (ETDEWEB)

Xia Jiliang; Ahokainen, T.; Holappa, L.

1998-12-31

Numerical investigation has been carried out for two phase flow in a bath agitated by top blowing lance injection. Eulerian two phase flow model is used. Lance immersion depth, injection gas flow rate, nozzle diameter, and bubble size have been systematically changed to examine their influence on the flow characteristics in the bath. It is found that there appear three typical flow patterns: one-vortex, two-vortex, and three-vortex type, with changing the injection gas flow rate or/and the nozzle diameter at moderate lance immersion depth. Predicted velocities are in a good agreement with Iguchi et al.`s experimental data and the main findings are also consistent with the measurements and observations of Chatterjee and Hsiao and Lehner. (orig.) 24 refs. Computational Fluid Dynamics Technology Programme
Intensity modulated tangential beam irradiation of the intact breast

International Nuclear Information System (INIS)

Hong, L.; Hunt, M.; Chui, C.; Forster, K.; Lee, H.; Lutz, W.; Yahalom, J.; Kutcher, G.J.; McCormick, B.

1997-01-01

Purpose/Objective: The purpose of this study was to evaluate the potential benefits of intensity modulated tangential beams in the irradiation of the intact breast. The primary goal was to develop an intensity modulated treatment which would substantially decrease the dose to coronary arteries, lung and contralateral breast while still using a standard tangential beam arrangement. Improved target dose homogeneity, within the limits imposed by opposed fields, was also desired. Since a major goal of the study was the development of a technique which was practical for use on a large population of patients, the design of 'standard' intensity profiles analogous in function to conventional wedges was also investigated. Materials and Methods: Three dimensional treatment planning was performed using both conventional and intensity modulated tangential beams. Plans were developed for both the right and left breast for a range of patient sizes and shapes. For each patient, PTV, lung, heart, origin and peripheral branches of the coronary artery, and contralateral breast were contoured. Optimum tangential beam direction and shape were designed using Beams-Eye-View display and then used for both the conventional and intensity modulated plans. For the conventional plan, the optimum wedge combination and beam weighting were chosen based on the dose distribution in a single transverse plane through the field center. Intensity modulated plans were designed using an algorithm which allows the user to specify the prescribed, maximum and minimum acceptable doses and dose volume constraints for each organ of interest. Plans were compared using multiple dose distributions and DVHs. Results: Significant improvements in the doses to critical structures were achieved using the intensity modulated plan. Coronary artery dose decreased substantially for patients treated to the left breast. Ipsilateral lung and contralateral breast doses decreased for all patients. For one patient treated to
Effects of magnetic drift tangential to magnetic surfaces on neoclassical transport in non-axisymmetric plasmas

International Nuclear Information System (INIS)

Matsuoka, Seikichi; Satake, Shinsuke; Kanno, Ryutaro; Sugama, Hideo

2015-01-01

In evaluating neoclassical transport by radially local simulations, the magnetic drift tangential to a flux surface is usually ignored in order to keep the phase-space volume conservation. In this paper, effect of the tangential magnetic drift on the local neoclassical transport is investigated. To retain the effect of the tangential magnetic drift in the local treatment of neoclassical transport, a new local formulation for the drift kinetic simulation is developed. The compressibility of the phase-space volume caused by the tangential magnetic drift is regarded as a source term for the drift kinetic equation, which is solved by using a two-weight δf Monte Carlo method for non-Hamiltonian system [G. Hu and J. A. Krommes, Phys. Plasmas 1, 863 (1994)]. It is demonstrated that the effect of the drift is negligible for the neoclassical transport in tokamaks. In non-axisymmetric systems, however, the tangential magnetic drift substantially changes the dependence of the neoclassical transport on the radial electric field E r . The peaked behavior of the neoclassical radial fluxes around E r = 0 observed in conventional local neoclassical transport simulations is removed by taking the tangential magnetic drift into account
Effects of magnetic drift tangential to magnetic surfaces on neoclassical transport in non-axisymmetric plasmas

Energy Technology Data Exchange (ETDEWEB)

Matsuoka, Seikichi, E-mail: matsuoka@rist.or.jp [Research Organization for Information Science and Technology, 6F Kimec-Center Build., 1-5-2 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047 (Japan); Satake, Shinsuke; Kanno, Ryutaro [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Department of Fusion Science, SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Sugama, Hideo [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)

2015-07-15

In evaluating neoclassical transport by radially local simulations, the magnetic drift tangential to a flux surface is usually ignored in order to keep the phase-space volume conservation. In this paper, effect of the tangential magnetic drift on the local neoclassical transport is investigated. To retain the effect of the tangential magnetic drift in the local treatment of neoclassical transport, a new local formulation for the drift kinetic simulation is developed. The compressibility of the phase-space volume caused by the tangential magnetic drift is regarded as a source term for the drift kinetic equation, which is solved by using a two-weight δf Monte Carlo method for non-Hamiltonian system [G. Hu and J. A. Krommes, Phys. Plasmas 1, 863 (1994)]. It is demonstrated that the effect of the drift is negligible for the neoclassical transport in tokamaks. In non-axisymmetric systems, however, the tangential magnetic drift substantially changes the dependence of the neoclassical transport on the radial electric field E{sub r}. The peaked behavior of the neoclassical radial fluxes around E{sub r }={sub }0 observed in conventional local neoclassical transport simulations is removed by taking the tangential magnetic drift into account.
Mathematical modeling of flow-injection techniques and their applications for environmental monitoring

International Nuclear Information System (INIS)

Begum, N.N.; Ahmed, J.

2006-01-01

A classification of the existing mathematical models of flow-injection (FI) manifolds based on the main principles on which they are built, have been proposed. Numerous mathematical models of FI systems employing ideas from different scientific areas (e.g. mathematical statistics, chemical engineering, chromatography) have been developed so far. The models have been compared with respect to their predictive power, the complexity of their mathematical treatment, and the requirements for computation time when applied to single-line, multi-channel and conjugated two-line FI systems. It is concluded that the axially dispersed plug flow model deserves special attention because it offers an acceptable compromise between the conflicting requirements for maximal possible mathematical simplicity and maximal possible precision. Applicability of these existing flow-injection models to single-line, multi-channel and conjugated two-line systems for environmental monitoring have been discussed. (author)

Transverse injection into Mach 2 flow behind a rearward-facing step - A 3-D, compressible flow test case for hypersonic combustor CFD validation

Science.gov (United States)

Mcdaniel, James C.; Fletcher, Douglas G.; Hartfield, Roy J.; Hollo, Steven D.

1991-01-01

A spatially-complete data set of the important primitive flow variables is presented for the complex, nonreacting, 3D unit combustor flow field employing transverse injection into a Mach 2 flow behind a rearward-facing step. A unique wind tunnel facility providing the capability for iodine seeding was built specifically for these measurements. Two optical techniques based on laser-induced-iodine fluorescence were developed and utilized for nonintrusive, in situ flow field measurements. LDA provided both mean and fluctuating velocity component measurements. A thermographic phosphor wall temperature measurement technique was developed and employed. Data from the 2D flow over a rearward-facing step and the complex 3D mixing flow with injection are reported.
Improvement of Power Flow Calculation with Optimization Factor Based on Current Injection Method

Directory of Open Access Journals (Sweden)

Lei Wang

2014-01-01

Full Text Available This paper presents an improvement in power flow calculation based on current injection method by introducing optimization factor. In the method proposed by this paper, the PQ buses are represented by current mismatches while the PV buses are represented by power mismatches. It is different from the representations in conventional current injection power flow equations. By using the combined power and current injection mismatches method, the number of the equations required can be decreased to only one for each PV bus. The optimization factor is used to improve the iteration process and to ensure the effectiveness of the improved method proposed when the system is ill-conditioned. To verify the effectiveness of the method, the IEEE test systems are tested by conventional current injection method and the improved method proposed separately. Then the results are compared. The comparisons show that the optimization factor improves the convergence character effectively, especially that when the system is at high loading level and R/X ratio, the iteration number is one or two times less than the conventional current injection method. When the overloading condition of the system is serious, the iteration number in this paper appears 4 times less than the conventional current injection method.
Three-dimensional turbulent swirling flow in a cylinder: Experiments and computations

International Nuclear Information System (INIS)

Gupta, Amit; Kumar, Ranganathan

2007-01-01

Dynamics of the three-dimensional flow in a cyclone with tangential inlet and tangential exit were studied using particle tracking velocimetry (PTV) and a three-dimensional computational model. The PTV technique is described in this paper and appears to be well suited for the current flow situation. The flow was helical in nature and a secondary recirculating flow was observed and well predicted by computations using the RNG k-ε turbulence model. The secondary flow was characterized by a single vortex which circulated around the axis and occupied a large fraction of the cylinder diameter. The locus of the vortex center meandered around the cylinder axis, making one complete revolution for a cylinder aspect ratio of 2. Tangential velocities from both experiments and computations were compared and found to be in good agreement. The general structure of the flow does not vary significantly as the Reynolds number is increased. However, slight changes in all components of velocity and pressure were seen as the inlet velocity is increased. By increasing the inlet aspect ratio it was observed that the vortex meandering changed significantly
Three-dimensional turbulent swirling flow in a cylinder: Experiments and computations

Energy Technology Data Exchange (ETDEWEB)

Gupta, Amit [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Kumar, Ranganathan [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States)]. E-mail: rnkumar@mail.ucf.edu

2007-04-15

Dynamics of the three-dimensional flow in a cyclone with tangential inlet and tangential exit were studied using particle tracking velocimetry (PTV) and a three-dimensional computational model. The PTV technique is described in this paper and appears to be well suited for the current flow situation. The flow was helical in nature and a secondary recirculating flow was observed and well predicted by computations using the RNG k-{epsilon} turbulence model. The secondary flow was characterized by a single vortex which circulated around the axis and occupied a large fraction of the cylinder diameter. The locus of the vortex center meandered around the cylinder axis, making one complete revolution for a cylinder aspect ratio of 2. Tangential velocities from both experiments and computations were compared and found to be in good agreement. The general structure of the flow does not vary significantly as the Reynolds number is increased. However, slight changes in all components of velocity and pressure were seen as the inlet velocity is increased. By increasing the inlet aspect ratio it was observed that the vortex meandering changed significantly.
Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

Directory of Open Access Journals (Sweden)

Fuensanta SÃƒÂ¡nchez Rojas

2006-10-01

Full Text Available Optical techniques for chemical analysis are well established and sensors based on thesetechniques are now attracting considerable attention because of their importance in applications suchas environmental monitoring, biomedical sensing, and industrial process control. On the other hand,flow injection analysis (FIA is advisable for the rapid analysis of microliter volume samples and canbe interfaced directly to the chemical process. The FIA has become a widespread automatic analyticalmethod for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, andease of assembling. In this paper, an overview of flow injection determinations by using opticalchemical sensors is provided, and instrumentation, sensor design, and applications are discussed. Thiswork summarizes the most relevant manuscripts from 1980 to date referred to analysis using opticalchemical sensors in FIA.
Coupled Viscous Fluid Flow and Joint Deformation Analysis for Grout Injection in a Rock Joint

Science.gov (United States)

Kim, Hyung-Mok; Lee, Jong-Won; Yazdani, Mahmoud; Tohidi, Elham; Nejati, Hamid Reza; Park, Eui-Seob

2018-02-01

Fluid flow modeling is a major area of interest within the field of rock mechanics. The main objective of this study is to gain insight into the performance of grout injection inside jointed rock masses by numerical modeling of grout flow through a single rock joint. Grout flow has been widely simulated using non-Newtonian Bingham fluid characterized by two main parameters of dynamic viscosity and shear yield strength both of which are time dependent. The increasing value of these properties with injection time will apparently affect the parameters representing the grouting performance including grout penetration length and volumetric injection rate. In addition, through hydromechanical coupling a mutual influence between the injection pressure from the one side and the joint opening/closing behavior and the aperture profile variation on the other side is anticipated. This is capable of producing a considerable impact on grout spread within the rock joints. In this study based on the Bingham fluid model, a series of numerical analysis has been conducted using UDEC to simulate the flow of viscous grout in a single rock joint with smooth parallel surfaces. In these analyses, the time-dependent evolution of the grout fluid properties and the hydromechanical coupling have been considered to investigate their impact on grouting performance. In order to verify the validity of these simulations, the results of analyses including the grout penetration length and the injection flow rate were compared with a well-known analytical solution which is available for the simple case of constant grout properties and non-coupled hydraulic analysis. The comparison demonstrated that the grout penetration length can be overestimated when the time-dependent hardening of grout material is not considered. Moreover, due to the HM coupling, it was shown that the joint opening induced by injection pressure may have a considerable increasing impression on the values of penetration length and
The efficacy of IntraFlow intraosseous injection as a primary anesthesia technique.

Science.gov (United States)

Remmers, Todd; Glickman, Gerald; Spears, Robert; He, Jianing

2008-03-01

The purpose of this study was to compare the efficacy of intraosseous injection and inferior alveolar (IA) nerve block in anesthetizing mandibular posterior teeth with irreversible pulpitis. Thirty human subjects were randomly assigned to receive either intraosseous injection using the IntraFlow system (Pro-Dex Inc, Santa Ana, CA) or IA block as the primary anesthesia method. Pulpal anesthesia was evaluated via electric pulp testing at 4-minute intervals for 20 minutes. Two consecutive 80/80 readings were considered successful pulpal anesthesia. Anesthesia success or failure was recorded and groups compared. Intraosseous injection provided successful anesthesia in 13 of 15 subjects (87%). The IA block provided successful anesthesia in 9 of 15 subjects (60%). Although this difference was not statistically significant (p = 0.2148), the results of this preliminary study indicate that the IntraFlow system can be used as the primary anesthesia method in teeth with irreversible pulpitis to achieve predictable pulpal anesthesia.
Jet flow analysis of liquid poison injection in a CANDU reactor using source term

International Nuclear Information System (INIS)

Chae, Kyung Myung; Choi, Hang Bok; Rhee, Bo Wook

2001-01-01

For the performance analysis of Canadian deuterium uranium (CANDU) reactor shutdown system number 2 (SDS2), a computational fluid dynamics model of poison jet flow has been developed to estimate the flow field and poison concentration formed inside the CANDU reactor calandria. As the ratio of calandria shell radius over injection nozzle hole diameter is so large (1055), it is impractical to develop a full-size model encompassing the whole calandria shell. In order to reduce the model to a manageable size, a quarter of one-pitch length segment of the shell was modeled using symmetric nature of the jet; and the injected jet was treated as a source term to avoid the modeling difficulty caused by the big difference of the hole sizes. For the analysis of an actual CANDU-6 SDS2 poison injection, the grid structure was determined based on the results of two-dimensional real- and source-jet simulations. The maximum injection velocity of the liquid poison is 27.8 m/s and the mass fraction of the poison is 8000 ppm (mg/kg). The simulation results have shown well-established jet flow field. In general, the jet develops narrowly at first but stretches rapidly. Then, the flow recirculates a little in r-x plane, while it recirculates largely in r-θ plane. As the time goes on, the adjacent jets contact each other and form a wavy front such that the whole jet develops in a plate form. his study has shown that the source term model can be effectively used for the analysis of the poison injection and the simulation result of the CANDU reactor is consistent with the model currently being used for the safety analysis. In the future, it is strongly recommended to analyze the transient (from helium tank to injection nozzle hole) of the poison injection by applying Bernoulli equation with real boundary conditions
Fluoroscopically Guided Extraforaminal Cervical Nerve Root Blocks: Analysis of Epidural Flow of the Injectate with Respect to Needle Tip Position

Science.gov (United States)

Shipley, Kyle; Riew, K. Daniel; Gilula, Louis A.

2013-01-01

Study Design Retrospective evaluation of consecutively performed fluoroscopically guided cervical nerve root blocks. Objective To describe the incidence of injectate central epidural flow with respect to needle tip position during fluoroscopically guided extraforaminal cervical nerve root blocks (ECNRBs). Methods Between February 19, 2003 and June 11, 2003, 132 consecutive fluoroscopically guided ECNRBs performed with contrast media in the final injected material (injectate) were reviewed on 95 patients with average of 1.3 injections per patient. Fluoroscopic spot images documenting the procedure were obtained as part of standard quality assurance. An independent observer not directly involved in the procedures retrospectively reviewed the images, and the data were placed into a database. Image review was performed to determine optimal needle tip positioning for injectate epidural flow. Results Central epidural injectate flow was obtained in only 28.9% of injections with the needle tip lateral to midline of the lateral mass (zone 2). 83.8% of injectate went into epidural space when the needle tip was medial to midline of the lateral mass (zone 3). 100% of injectate flowed epidurally when the needle tip was medial to or at the medial cortex of the lateral mass (zone 4). There was no statistically significant difference with regards to central epidural flow and the needle tip position on lateral view. Conclusion To ensure central epidural flow with ECNRBs one must be prepared to pass the needle tip medial to midplane of the lateral mass or to medial cortex of the lateral mass. Approximately 16% of ECNRBs with needle tip medial to midline of the lateral mass did not flow into epidural space. One cannot claim a nerve block is an epidural block unless epidural flow of injectate is observed. PMID:24494176
Development of an automated flow injection analysis system for determination of phosphate in nutrient solutions.

Science.gov (United States)

Karadağ, Sevinç; Görüşük, Emine M; Çetinkaya, Ebru; Deveci, Seda; Dönmez, Koray B; Uncuoğlu, Emre; Doğu, Mustafa

2018-01-25

A fully automated flow injection analysis (FIA) system was developed for determination of phosphate ion in nutrient solutions. This newly developed FIA system is a portable, rapid and sensitive measuring instrument that allows on-line analysis and monitoring of phosphate ion concentration in nutrient solutions. The molybdenum blue method, which is widely used in FIA phosphate analysis, was adapted to the developed FIA system. The method is based on the formation of ammonium Mo(VI) ion by reaction of ammonium molybdate with the phosphate ion present in the medium. The Mo(VI) ion then reacts with ascorbic acid and is reduced to the spectrometrically measurable Mo(V) ion. New software specific for flow analysis was developed in the LabVIEW development environment to control all the components of the FIA system. The important factors affecting the analytical signal were identified as reagent flow rate, injection volume and post-injection flow path length, and they were optimized using Box-Behnken experimental design and response surface methodology. The optimum point for the maximum analytical signal was calculated as 0.50 mL min -1 reagent flow rate, 100 µL sample injection volume and 60 cm post-injection flow path length. The proposed FIA system had a sampling frequency of 100 samples per hour over a linear working range of 3-100 mg L -1 (R 2 = 0.9995). The relative standard deviation (RSD) was 1.09% and the limit of detection (LOD) was 0.34 mg L -1 . Various nutrient solutions from a tomato-growing hydroponic greenhouse were analyzed with the developed FIA system and the results were found to be in good agreement with vanadomolybdate chemical method findings. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.
O-(Î²-hydroxyethylrutosides determination by micellar flow injection (FI-spectrofluorimetry

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Cecilia Mariana Peralta

2014-12-01

Full Text Available A simple, eco-friendly, sensitive and economic flow injection spectrofluorimetric method was developed for the determination of O-(Î²-hydroxyethylrutosides. The procedure was based on the use of an anionic surfactant such as sodium dodecyl sulfate to provide an appreciable O-(Î²-hydroxyethylrutosides fluorescence enhancement, increasing considerably the sensitivity of detection. All the variables affecting the fluorescence intensity were studied and optimized. The flow rate was 5Â mL/min with detection at 450Â nm (after excitation at 346Â nm. A linear correlation between drug amount and peak area was established for O-(Î²-hydroxyethylrutosides in the range of 0.01â200Â Âµg/mL with a detection limit of 0.001Â Âµg/mL (s/n=3. Validation processes were performed by recovering studies with satisfactory results. The new methodology can be employed for the routine analysis of O-(Î²-hydroxyethylrutosides in bulks as well as in commercial formulations. Keywords: O-(Î²-hydroxyethylrutosides, Micellar enhancement, Flow injection, Spectrofluorimetry, Pharmaceuticals
An experimental study of the flow characteristics of fluidic device in a passive safety injection tank

International Nuclear Information System (INIS)

Cho, Seok; Song, Chul Hwa; Won, Suon Yeon; Min, Kyong Ho; Chung, Moon Ki

1998-01-01

It is considered to adopt passive safety injection tank (SIT) as a enhanced safety feature in KNGR. Passive SIT employs a vortex chamber as a fluidic device, which control injection flow rate passively by the variation of flow resistance produced by vortex intensity within the vortex chamber. To investigate the flow characteristics of the vortex chamber many tests have been carried out by using small-scale test facility. In this report the effects of geometric parameters of vortex chamber on discharge flow characteristics and the velocity measurement result of flow field, measured by PIV, are presented and discussed. (author). 25 refs., 11 tabs., 31 figs
Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

Science.gov (United States)

Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

2015-08-14

Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment.
CFD analysis of temperature imbalance in superheater/reheater region of tangentially coal-fired boiler

Science.gov (United States)

Zainudin, A. F.; Hasini, H.; Fadhil, S. S. A.

2017-10-01

This paper presents a CFD analysis of the flow, velocity and temperature distribution in a 700 MW tangentially coal-fired boiler operating in Malaysia. The main objective of the analysis is to gain insights on the occurrences in the boiler so as to understand the inherent steam temperature imbalance problem. The results show that the root cause of the problem comes from the residual swirl in the horizontal pass. The deflection of the residual swirl due to the sudden reduction and expansion of the flow cross-sectional area causes velocity deviation between the left and right side of the boiler. This consequently results in flue gas temperature imbalance which has often caused tube leaks in the superheater/reheater region. Therefore, eliminating the residual swirl or restraining it from being diverted might help to alleviate the problem.
Home-Made Micro Valve for Determining Malachite Green Dye by Flow Injection Analysis

Directory of Open Access Journals (Sweden)

Amal Saadoon Majeed

2017-07-01

Full Text Available The research is included studying and designing micro flow injection system which is characterized with rapidity, simplicity, and low cost for the determination of green malachite dye. The study of flow rate of carrier stream, repeatability, dispersion coefficient, and calibration graph are conducted. It is found that the optimum conditions for the determination of mentioned dye are flow rate 4.200 mL/min, sampling rate 102 sample/h, limit of detection 0.05 ppm, linear range (0.05-18.00 ppm with linearity (R2=0.9700, RSD is 0.355, the repeatability for seven successive injections is studied for the two concentrations 5 ppm and 12 ppm, and the dispersion coefficient values are 1.73 and 1.28 at the two concentrations 2 ppm and 9 ppm respectively.
Stopped-flow injection spectrophotometric method for determination of chlorate in soil

Directory of Open Access Journals (Sweden)

Jaroon Jakmunee

2008-06-01

Full Text Available A stopped-flow injection (FI spectrophotometric procedure based on iodometric reaction for the determination of chlorate has been developed. Standard/sample was injected into a stream of potassium iodide solution and then merged with a stream of hydrochloric acid solution to produce triiodide. By stopping the flow while the sample zone is being in a mixing coil, a slow reaction of chlorate with iodide in acidic medium was promoted to proceed with minimal dispersion of the triiodide product zone. When the flow started again, a concentrated product zone was pushed into a flow cell and a signal profile due to light absorption of the product was recorded. Employing a lab-built semi-automatic stopped-FI analyser, the analysis can be performed with higher degree of automation and low chemical consumption. Linear calibration graph in the range of 5-50 mg ClO3- L-1 was obtained, with detection limit of 1.4 mg ClO3- L-1. Relative standard deviation of 2.2% (30 mg ClO3- L-1, n=10 and sample throughput of about 20 h-1 were achieved. The system was applied to soil samples and validated by batch spectrophotometric and standard titrimetric methods.
Continuous-Flow Production of Injectable Liposomes via a Microfluidic Approach

Science.gov (United States)

Zizzari, Alessandra; Bianco, Monica; Perrone, Elisabetta; Amato, Francesco; Maruccio, Giuseppe; Rendina, Filippo; Arima, Valentina

2017-01-01

Injectable liposomes are characterized by a suitable size and unique lipid mixtures, which require time-consuming and nonstraightforward production processes. The complexity of the manufacturing methods may affect liposome solubility, the phase transition temperatures of the membranes, the average particle size, and the associated particle size distribution, with a possible impact on the drug encapsulation and release. By leveraging the precise steady-state control over the mixing of miscible liquids and a highly efficient heat transfer, microfluidic technology has proved to be an effective and direct methodology to produce liposomes. This approach results particularly efficient in reducing the number of the sizing steps, when compared to standard industrial methods. Here, Microfluidic Hydrodynamic Focusing chips were produced and used to form liposomes upon tuning experimental parameters such as lipids concentration and Flow-Rate-Ratios (FRRs). Although modelling evidenced the dependence of the laminar flow on the geometric constraints and the FRR conditions, for the specific formulation investigated in this study, the lipids concentration was identified as the primary factor influencing the size of the liposomes and their polydispersity index. This was attributed to a predominance of the bending elasticity modulus over the vesiculation index in the lipid mixture used. Eventually, liposomes of injectable size were produced using microfluidic one-pot synthesis in continuous flow. PMID:29232873
Tangential channel for nuclear gamma-resonance spectroscopy in thermal neutron capture

International Nuclear Information System (INIS)

Belogurov, V.N.; Bondars, H.Ya.; Lapenas, A.A.; Reznikov, R.S.; Senkov, P.E.

1979-01-01

Design of a tangential reactor channel which has been made to replace the radial one in the pulsed research reactor IRT-2000 is described. It allows to use the same hole in biological reactor schielding. Characteristics of neutron and gamma-background spectra at the excit of the channel are given and compared with analogous characteristics of the radial one. The gamma background in the tangential channel is lower than in the radial channel. The gamma spectra in the Gd 155 (n, γ)Gd 156 , Gd 157 (n, γ)Gd 158 , Er 167 (n, γ)Er 168 and Hf 177 (n, γ)Hf 178 reactions show that the application of X-ray detection units BDR with the tangential channel allows to carry out the gamma spectrometry of gamma quanta emitted in the thermal neutron capture by both high and low neutron capture cross section nuclei (e.g., Gdsup(157, 155) and Er 167 , Hf 177 , respectively)
Stability Analysis of High-Speed Boundary-Layer Flow with Gas Injection

Science.gov (United States)

2014-06-01

laminar-turbulent transition on slender bodies in a hypersonic flow at small angles of attack is caused by amplification of acoustic waves trapped in...x decreases and slowly approaches the no-blow distribution. These CFD data demonstrate that the injection strongly affects the near-wall flow...conclusion. Figure 10 shows that the spatial growth rates ( )  are maximal for mode 0 corresponding to the Mack second mode – typical for hypersonic
Theoretical considerations of Flow Injection Analysis in the Absence of Chemical Reactions

DEFF Research Database (Denmark)

Andersen, Jens Enevold Thaulov

2000-01-01

The fundamental mechanism of flow injection analysis (FIA) is assumed to be simple dissusion and the response of the detector is included in a model description that provide information about the shape of the FIA peak in terms of, basically, five parameters. Two of the five parameters are associa...... that any deviation from the features of the present model and the results of a tentative chemical reaction with one of the test compounds, is related to chemical kinetics.......The fundamental mechanism of flow injection analysis (FIA) is assumed to be simple dissusion and the response of the detector is included in a model description that provide information about the shape of the FIA peak in terms of, basically, five parameters. Two of the five parameters...

An experimental and numerical study of endwall heat transfer in a turbine blade cascade including tangential heat conduction analysis

Science.gov (United States)

Ratto, Luca; Satta, Francesca; Tanda, Giovanni

2018-06-01

This paper presents an experimental and numerical investigation of heat transfer in the endwall region of a large scale turbine cascade. The steady-state liquid crystal technique has been used to obtain the map of the heat transfer coefficient for a constant heat flux boundary condition. In the presence of two- and three-dimensional flows with significant spatial variations of the heat transfer coefficient, tangential heat conduction could lead to error in the heat transfer coefficient determination, since local heat fluxes at the wall-to-fluid interface tend to differ from point to point and surface temperatures to be smoothed out, thus making the uniform-heat-flux boundary condition difficult to be perfectly achieved. For this reason, numerical simulations of flow and heat transfer in the cascade including the effect of tangential heat conduction inside the endwall have been performed. The major objective of numerical simulations was to investigate the influence of wall heat conduction on the convective heat transfer coefficient determined during a nominal iso-flux heat transfer experiment and to interpret possible differences between numerical and experimental heat transfer results. Results were presented and discussed in terms of local Nusselt number and a convenient wall heat flux function for two values of the Reynolds number (270,000 and 960,000).
Absence of Tangentially Migrating Glutamatergic Neurons in the Developing Avian Brain

Directory of Open Access Journals (Sweden)

Fernando García-Moreno

2018-01-01

Full Text Available Summary: Several neuronal populations orchestrate neocortical development during mammalian embryogenesis. These include the glutamatergic subplate-, Cajal-Retzius-, and ventral pallium-derived populations, which coordinate cortical wiring, migration, and proliferation, respectively. These transient populations are primarily derived from other non-cortical pallial sources that migrate to the dorsal pallium. Are these migrations to the dorsal pallium conserved in amniotes or are they specific to mammals? Using in ovo electroporation, we traced the entire lineage of defined chick telencephalic progenitors. We found that several pallial sources that produce tangential migratory neurons in mammals only produced radially migrating neurons in the avian brain. Moreover, ectopic expression of VP-specific mammalian Dbx1 in avian brains altered neurogenesis but did not convert the migration into a mammal-like tangential movement. Together, these data indicate that tangential cellular contributions of glutamatergic neurons originate from outside the dorsal pallium and that pallial Dbx1 expression may underlie the generation of the mammalian neocortex during evolution. : Neocortical formation crucially depends on the early tangential arrival of several transient glutamatergic neuronal populations. García-Moreno et al. find that these neuronal migrations are absent in the developing brain of chicks. The mammalian uniqueness of these developing migrations suggests a crucial role of these cells in the evolutionary origin of the neocortex. Keywords: neocortex, chick, pallium, ventral pallium, evo-devo, evolution, Dbx1, telencephalon
Determination of albumin in bronchoalveolar lavage fluid by flow-injection fluorometry using chromazurol S.

Science.gov (United States)

Sato, Takaji; Saito, Yoshihiro; Chikuma, Masahiko; Saito, Yutaka; Nagai, Sonoko

2008-03-01

A highly sensitive flow injection fluorometry for the determination of albumin was developed and applied to the determination of albumin in human bronchoalveolar lavage fluids (BALF). This method is based on binding of chromazurol S (CAS) to albumin. The calibration curve was linear in the range of 5-200 microg/ml of albumin. A highly linear correlation (r=0.986) was observed between the albumin level in BALF samples (n=25) determined by the proposed method and by a conventional fluorometric method using CAS (CAS manual method). The IgG interference was lower in the CAS flow injection method than in the CAS manual method. The albumin level in BALF collected from healthy volunteers (n=10) was 58.5+/-13.1 microg/ml. The albumin levels in BALF samples obtained from patients with sarcoidosis and idiopathic pulmonary fibrosis were increased. This finding shows that the determination of albumin levels in BALF samples is useful for investigating lung diseases and that CAS flow injection method is promising in the determination of trace albumin in BALF samples, because it is sensitive and precise.
Non-darcy flow behavior mean high-flux injection wells in porous and fractured formations

Energy Technology Data Exchange (ETDEWEB)

Wu, Yu-Shu

2003-04-25

This paper presents a study of non-Darcy fluid flow through porous and fractured rock, which may occur near wells during high-flux injection of waste fluids into underground formations. Both numerical and analytical models are used in this study. General non-Darcy flow is described using the Forchheimer equation, implemented in a three-dimensional, multiphase flow reservoir simulator. The non-Darcy flow through a fractured reservoir is handled using a general dual continuum approach, covering commonly used conceptual models, such as double porosity, dual permeability, explicit fracture, etc. Under single-phase flow conditions, an approximate analytical solution, as an extension of the Warren-Root solution, is discussed. The objectives of this study are (1) to obtain insights into the effect of non-Darcy flow on transient pressure behavior through porous and fractured reservoirs and (2) to provide type curves for well test analyses of non-Darcy flow wells. The type curves generated include various types of drawdown, injection, and buildup tests with non-Darcy flow occurring in porous and fractured reservoirs. In addition, non-Darcy flow into partially penetrating wells is also considered. The transient-pressure type curves for flow in fractured reservoirs are based on the double-porosity model. Type curves provided in this work for non-Darcy flow in porous and fractured reservoirs will find their applications in well test interpretation using a type-curve matching technique.
Continuous-Flow Production of Injectable Liposomes via a Microfluidic Approach

Directory of Open Access Journals (Sweden)

Alessandra Zizzari

2017-12-01

Full Text Available Injectable liposomes are characterized by a suitable size and unique lipid mixtures, which require time-consuming and nonstraightforward production processes. The complexity of the manufacturing methods may affect liposome solubility, the phase transition temperatures of the membranes, the average particle size, and the associated particle size distribution, with a possible impact on the drug encapsulation and release. By leveraging the precise steady-state control over the mixing of miscible liquids and a highly efficient heat transfer, microfluidic technology has proved to be an effective and direct methodology to produce liposomes. This approach results particularly efficient in reducing the number of the sizing steps, when compared to standard industrial methods. Here, Microfluidic Hydrodynamic Focusing chips were produced and used to form liposomes upon tuning experimental parameters such as lipids concentration and Flow-Rate-Ratios (FRRs. Although modelling evidenced the dependence of the laminar flow on the geometric constraints and the FRR conditions, for the specific formulation investigated in this study, the lipids concentration was identified as the primary factor influencing the size of the liposomes and their polydispersity index. This was attributed to a predominance of the bending elasticity modulus over the vesiculation index in the lipid mixture used. Eventually, liposomes of injectable size were produced using microfluidic one-pot synthesis in continuous flow.
Heating efficiency of high-power perpendicular neutral-beam injection in PDX

International Nuclear Information System (INIS)

Hawryluk, R.J.; Arunasalam, V.; Bell, M.

1982-03-01

The heating efficiency of high power (up to 7.2 MW) near-perpendicular neutral beam injection in the PDX tokamak is comparable to that of tangential injection in PLT. Collisionless plasmas with central ion temperatures up to 6.5 keV and central electron temperatures greater than 2.5 keV have been obtained. The plasma pressure, including the contribution from the beam particles, increases with increasing beam power and does not appear to saturate, although the parametric dependence of the energy confinement time is different from that observed in ohmic discharges
Entropy Generation in a Rotating Couette Flow with Suction/Injection

Directory of Open Access Journals (Sweden)

S. Das

2015-05-01

Full Text Available The present paper is concerned with an analytical study of entropy generation in viscous incompressible Couette flow with suction/injection in a rotating frame of reference. One of the plate is held at rest and the other one moves with an uniform velocity.The flow induced by the moving plate. An exact solution of governing equations has been obtained in closed form. The entropy generation number and the Bejan number are also obtained. The influences of each of the governing parameters on velocity, temperature, entropy generation and Bejan number are discussed with the help of graphs.
Enzymatic amplification of a flow-injected thermometric enzyme-linked immunoassay for human insulin.

Science.gov (United States)

Mecklenburg, M; Lindbladh, C; Li, H; Mosbach, K; Danielsson, B

1993-08-01

A flow-injected thermometric enzyme linked immunoassay for human insulin which employs the lactate dehydrogenase/lactate oxidase (LDH/LOD) substrate recycling system for signal amplification is described. The system is composed of two columns, an immunosorbent column containing immobilized anti-insulin antibodies for sensing and a recycling column containing immobilized LDH/LOD/Catalase for detection. The effect of flow rates, conjugate concentrations, and chromatographic support material upon the sensitivity of the assay are investigated. The assay has a detection limit of 0.025 microgram/ml and a linear range from 0.05 to 2 micrograms/ml. This corresponds to a 10-fold increase in sensitivity over the unamplified system. A recombinant human insulin-proinsulin conjugate was also tested. The results show that enzymatic amplification can be employed to increase the sensitivity and reproducibility of flow injection assay-based biosensors. The implications of these results upon on-line analysis are discussed.
Flow injection analysis: Emerging tool for laboratory automation in radiochemistry

International Nuclear Information System (INIS)

Egorov, O.; Ruzicka, J.; Grate, J.W.; Janata, J.

1996-01-01

Automation of routine and serial assays is a common practice of modern analytical laboratory, while it is virtually nonexistent in the field of radiochemistry. Flow injection analysis (FIA) is a general solution handling methodology that has been extensively used for automation of routine assays in many areas of analytical chemistry. Reproducible automated solution handling and on-line separation capabilities are among several distinctive features that make FI a very promising, yet under utilized tool for automation in analytical radiochemistry. The potential of the technique is demonstrated through the development of an automated 90 Sr analyzer and its application in the analysis of tank waste samples from the Hanford site. Sequential injection (SI), the latest generation of FIA, is used to rapidly separate 90 Sr from interfering radionuclides and deliver separated Sr zone to a flow-through liquid scintillation detector. The separation is performed on a mini column containing Sr-specific sorbent extraction material, which selectively retains Sr under acidic conditions. The 90 Sr is eluted with water, mixed with scintillation cocktail, and sent through the flow cell of a flow through counter, where 90 Sr radioactivity is detected as a transient signal. Both peak area and peak height can be used for quantification of sample radioactivity. Alternatively, stopped flow detection can be performed to improve detection precision for low activity samples. The authors current research activities are focused on expansion of radiochemical applications of FIA methodology, with an ultimate goal of creating a set of automated methods that will cover the basic needs of radiochemical analysis at the Hanford site. The results of preliminary experiments indicate that FIA is a highly suitable technique for the automation of chemically more challenging separations, such as separation of actinide elements
Exploiting flow injection and sequential injection for trace metal determinations in conjunction with detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

DEFF Research Database (Denmark)

Hansen, Elo Harald

and selectivity. Either in order to separate/preconcentrate the analyte material, or because of the presence of potentially interfering matrix constituents. Such pretreatments are advantageously performed in flow injection (FI) or sequential injection (SI) manifolds, where all appropriate unit operations can...
Measurement of injected Sr in the stem of a Japanese cedar (Cryptomeria japonica D. Don) using PIXE

International Nuclear Information System (INIS)

Katayama, Y.; Aoki, T.; Ko, S.; Yoshida, K.

1999-01-01

Distribution profiles of Sr injected into the stem of a Japanese cedar (Cryptomeria japonica D. Don) were determined using PIXE. The Sr injected into the middle of the sapwood of the cedar stem moved upwards easily along the grain. The Sr in the stem moved in a radial direction in the sapwood section (assumed to be through the ray) and there was almost no tangential movement. (author)
Optimization of a flow injection analysis system for multiple solvent extraction

International Nuclear Information System (INIS)

Rossi, T.M.; Shelly, D.C.; Warner, I.M.

1982-01-01

The performance of a multistage flow injection analysis solvent extraction system has been optimized. The effect of solvent segmentation devices, extraction coils, and phase separators on performance characteristics is discussed. Theoretical consideration is given to the effects and determination of dispersion and the extraction dynamics within both glass and Teflon extraction coils. The optimized system has a sample recovery similar to an identical manual procedure and a 1.5% relative standard deviation between injections. Sample throughput time is under 5 min. These characteristics represent significant improvements over the performance of the same system before optimization. 6 figures, 2 tables
Accuracy in tangential breast treatment set-up

International Nuclear Information System (INIS)

Tienhoven, G. van; Lanson, J.H.; Crabeels, D.; Heukelom, S.; Mijnheer, B.J.

1991-01-01

To test accuracy and reproducibility of tangential breast treatment set-up used in The Netherlands Cancer Institute, a portal imaging study was performed in 12 patients treated for early stage breast cancer. With an on-line electronic portal imaging device (EPID) images were obtained of each patient in several fractions and compared with simulator films and with each other. In 5 patients multiple images (on the average 7) per fraction were obtained to evaluate set-up variations due to respiratory movement. The central lung distance (CLD) and other set-up parameters varied within 1 fraction about 1mm (1SD). The average variation of these parameters between various fractions was about 2 mm (1SD). The differences between simulator and treatment set-up over all patients and all fractions was on the average 2-3mm for the central beam edge to skin distance and CLD. It can be concluded that the tangential breast treatment set-up is very stable and reproducible and that respiration does not have a significant influence on treatment volume. EPID appears to be an adequate tool for studies of treatment set-up accuracy like this. (author). 35 refs.; 2 figs.; 3 tabs
Determination of mercury by multisyringe flow injection system with cold-vapor atomic absorption spectrometry

International Nuclear Information System (INIS)

Leal, L.O.; Elsholz, O.; Forteza, R.; Cerda, V.

2006-01-01

A new software-controlled time-based multisyringe flow injection system for mercury determination by cold-vapor atomic absorption spectrometry is proposed. Precise known volumes of sample, reducing agent (1.1% SnCl 2 in 3% HCl) and carrier (3% HCl) are dispensed into a gas-liquid separation cell with a multisyringe burette coupled with one three-way solenoid valve. An argon flow delivers the reduced mercury to the spectrometer. The optimization of the system was carried out testing reaction coils and gas-liquid separators of different design as well as changing parameters, such as sample and reagents volumes, reagent concentrations and carrier gas flow rate, among others. The analytical curves were obtained within the range 50-5000 ng L -1 . The detection limit (3σ b /S) achieved is 5 ng L -1 . The relative standard deviation (R.S.D.) was 1.4%, evaluated from 16 successive injections of 250 ng L -1 Hg standard solution. The injection and sample throughput per hour were 44 and 11, respectively. This technique was validated by means of solid and water reference materials with good agreement with the certified values and was successfully applied to fish samples
Mode particle resonances during near-tangential neutral beam injection in large tokamaks

International Nuclear Information System (INIS)

Kaita, R.; White, R.B.; Morris, A.W.; Fredrickson, E.D.; McGuire, K.M.; Medley, S.S.; Scott, S.D.

1988-01-01

Coherent magnetohydrodynamic modes have been observed during neutral beam injection in TFTR and JET. Periodic bursts of oscillations were detected with several plasma diagnostics, and Fokker-Planck calculations show that the populations of trapped particles in both tokamaks are sufficient to account for fishbone destabilization. Estimates of mode parameters are in reasonable agreement with the experiments, and they indicate that the fishbone mode may continue to affect the performance of intensely heated tokamaks. 13 refs., 1 fig., 1 tab
Bubble-size distributions produced by wall injection of air into flowing freshwater, saltwater and surfactant solutions

Science.gov (United States)

Winkel, Eric S.; Ceccio, Steven L.; Dowling, David R.; Perlin, Marc

2004-12-01

As air is injected into a flowing liquid, the resultant bubble characteristics depend on the properties of the injector, near-wall flow, and flowing liquid. Previous research has shown that near-wall bubbles can significantly reduce skin-friction drag. Air was injected into the turbulent boundary layer on a test section wall of a water tunnel containing various concentrations of salt and surfactant (Triton-X-100, Union Carbide). Photographic records show that the mean bubble diameter decreased monotonically with increasing salt and surfactant concentrations. Here, 33 ppt saltwater bubbles had one quarter, and 20 ppm Triton-X-100 bubbles had one half of the mean diameter of freshwater bubbles.
Irreversibility analysis of magneto-hydrodynamic nanofluid flow injected through a rotary disk

Directory of Open Access Journals (Sweden)

Rashidi Mohammad Mehdi

2015-01-01

Full Text Available The non-linear Navier-Stokes equations governed on the nanofluid flow injected through a rotary porous disk in the presence of an external uniform vertical magnetic field can be changed to a system of non-linear partial differential equations by applying similar parameter. In this study, partial differential equations are analytically solved by the modified differential transform method, Pade differential transformation method to obtain self-similar functions of motion and temperature. A very good agreement is observed between the obtained results of Pade differential transformation method and those of previously published ones. Then it has become possible to do a comprehensive parametric analysis on the entropy generation in this case to demonstrate the effects of physical flow parameters such as magnetic interaction parameter, injection parameter, nanoparticle volume fraction, dimensionless temperature difference, rotational Brinkman number and the type of nanofluid on the problem.
Spectrofluorimetric determination of cerium by flow injection analysis

International Nuclear Information System (INIS)

Liu Shaorong; Meng Jian; Liu Wenhua

1990-01-01

A spectrofluorimetric method for the determination of cerium (λ ex/em:251/365 nm) in hydrochloric acid solution by flow injection analysis is presented. It has well developed the normal spectrofluorimetric method for determination of cerium and has made: 1, the determination procedure shortened; 2, the determination speed increased to about 180 samples per hour; 3, the determination range widened to 0.05-100.0 ppm CeO 2 , abouot two times as wide as the normal spectrofluorimetric method; and 4, the relative standard deviation lessened (about 0.47% for 0.1 ppm CeO 2 , n = 13)
The irradiation lung volume in tangential fields for the treatment of a breast

International Nuclear Information System (INIS)

Oh, Y. T.; Kim, J. R.; Kang, H. J.; Sohn, J. H.; Kang, S. H.; Chun, M. S.

1997-01-01

Radiation pneumonitis is one of the complications caused by radiation therapy that includes a portion of the lung tissue. The severity of radiation induced pulmonary dysfunction depends on the irradiated lung volume, total dose, dose rate and underlying pulmonary function. The lung volume was measured for 25 patients with breast cancer irradiated with tangential field from Jan. 1995 to Aug. 1996. Parameters that can predict the irradiated lung volume included; (1) the perpendicular distance from the posterior tangential edge to the posterior part of the anterior chest wall at the center of the field (CLD); (2) the maximum perpendicular distance from the posterior tangential field edge to the posterior part of the anterior chest wall (MLD); (3) the greatest perpendicular distance from the posterior tangential edge to the posterior part of anterior chest wall on CT image at the center of the longitudinal field (GPD); (4) the length of the longitudinal field (L). The irradiated lung volume(RV), the entire both lung volume(EV) and the ipsilateral lung volume(IV) were measured using dose volume histogram. The RV is 61-279cc, the RV/EV is 2.9-13.0% and the RV/EN is 4.9-29.6%. The CLD, the MLD and the GPD are 1.9-3.3cm and 1.4-3.1cm respectively. The significant relations between the irradiated lung volume such as RV, RV/EV, RV/IV and parameters such as CLD, MLD, GPD, L, CLD x L, MLD x L and GPD x L are not found with little variances in parameters. The RV/IV of the left breast irradiation is significances. The significant relationship between the irradiated lung volume and predictors is not found with little variation on parameters. The irradiated lung volume in the tangential field is less than 10% of entire lung volume when CLD is less than 3cm. The RV/IV of the left tangential field is larger than that of the right but there was no significant differences in RV/EVs. Symptomatic radiation pneumonitis has not occurred during minimum 6 months follow up. (author)
On-line dynamic fractionation and automatic determination of inorganic phosphorous in environmental solid substrates exploiting sequential injection microcolumn extraction and flow injection analysi

DEFF Research Database (Denmark)

Buanuam, Janya; Miró, Manuel; Hansen, Elo Harald

2006-01-01

Sequential injection microcolumn extraction (SI-MCE) based on the implementation of a soil containing microcartridge as external reactor in a sequential injection network is, for the first time, proposed for dynamic fractionation of macronutrients in environmental solids, as exemplified by the pa......Sequential injection microcolumn extraction (SI-MCE) based on the implementation of a soil containing microcartridge as external reactor in a sequential injection network is, for the first time, proposed for dynamic fractionation of macronutrients in environmental solids, as exemplified...... by the partitioning of inorganic phosphorous in agricultural soils. The on-line fractionation method capitalises on the accurate metering and sequential exposure of the various extractants to the solid sample by application of programmable flow as precisely coordinated by a syringe pump. Three different soil phase...... associations for phosphorus, that is, exchangeable, Al- and Fe-bound and Ca-bound fractions, were elucidated by accommodation in the flow manifold of the 3 steps of the Hietjles-Litjkema (HL) scheme involving the use of 1.0 M NH4Cl, 0.1 M NaOH and 0.5 M HCl, respectively, as sequential leaching reagents...

Principles and Applications of Flow Injection Analysis in Biosensors

DEFF Research Database (Denmark)

Hansen, Elo Harald

1996-01-01

In practical applications biosensors are often forced to operate under less than optimal conditions. Because of their construction, and the physical processes and chemical reactions involved in their operation, compromise conditions are frequently required to synchronize all events taking place....... Therefore, and in order to implement functions such as periodic calibration, conditioning and possible regeneration of the biosensor, and, very importantly, to yield the freedom to select the optimum detection means, it is advantageous to use these devices in a flow-through mode, particularly by employing...... the flow injection (FI) approach. The capacity of FI, as offering itself as a complementary facility to augment the performance of biosensors, and in many cases as an attractive alternative, is demonstrated by reference to selected examples, comprising assays based on enzymatic procedures with optical...
MHD flow over a permeable stretching/shrinking sheet of a nanofluid with suction/injection

Directory of Open Access Journals (Sweden)

Sandeep Naramgari

2016-06-01

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

International Nuclear Information System (INIS)

Pessenda, L.C.R.

1987-03-01

A spectrophotometric flow injection analytical method based on the catalytic action of molybdenum on the oxidation of iodide by hydrogen peroxide in acidic medium is proposed for the molybdenum determination in plant digests. A cation exchange resin column is incorporated into a flow injection system for removal of interferents. The following system variables were investigated and optimized: reagent concentrations, sample injection volume, mixing and reaction coil lengths, temperature, sampling time, pumping rate and concentration of eluting agents. The effects of interfering species and of the acidity of samples on the molybdenum retention by the ion exchange resin column were investigated. The proposed method is characterized by good precision (r.s.d. (2.0%), a sampling rate of about 40 samples per hour, and permits the determination of molybdenum in plant digests in the range 1.0 to 40.0 μg/l. The results compare well with those obtained by graphite furnace atomic absorption spectrometry. (author) [pt
Towards Noncommutative Topological Quantum Field Theory: Tangential Hodge-Witten cohomology

International Nuclear Information System (INIS)

Zois, I P

2014-01-01

Some years ago we initiated a program to define Noncommutative Topological Quantum Field Theory (see [1]). The motivation came both from physics and mathematics: On the one hand, as far as physics is concerned, following the well-known holography principle of 't Hooft (which in turn appears essentially as a generalisation of the Hawking formula for black hole entropy), quantum gravity should be a topological quantum field theory. On the other hand as far as mathematics is concerned, the motivation came from the idea to replace the moduli space of flat connections with the Gabai moduli space of codim-1 taut foliations for 3 dim manifolds. In most cases the later is finite and much better behaved and one might use it to define some version of Donaldson-Floer homology which, hopefully, would be easier to compute. The use of foliations brings noncommutative geometry techniques immediately into the game. The basic tools are two: Cyclic cohomology of the corresponding foliation C*-algebra and the so called ''tangential cohomology'' of the foliation. A necessary step towards this goal is to develop some sort of Hodge theory both for cyclic (and Hochschild) cohomology and for tangential cohomology. Here we present a method to develop a Hodge theory for tangential cohomology of foliations by mimicing Witten's approach to ordinary Morse theory by perturbations of the Laplacian
Flow visualization and simulation of the filling process during injection molding

DEFF Research Database (Denmark)

Guerrier, Patrick; Tosello, Guido; Hattel, Jesper Henri

2017-01-01

To directly compare experimental moldings from an injection molding machine with simulations, a special mold has been produced with a glass window. The injection plane is perpendicular to the opening and closing planes, in order for the 55. mm thick glass window to be easily visible from the side....... These two had significant effects on the filling times and injection pressure calculated by the simulations. Other effects investigated included transient thermal management of the mold, pressure dependent viscosity and wall slip, but their effect were not remarkably large in this work. The obtained....... A high speed camera recording 500 frames per second was employed, and the mold had three thermocouples and two pressure sensors installed. The molded part is a 2. mm thick plate with a 0.5. mm thin section, which creates a characteristic V-shaped flow pattern. Two different materials were employed...
Dual-phase gas-permeation flow-injection thermometric analysis for the determination of carbon dioxide.

Science.gov (United States)

Liu, S J; Tubino, M

1998-11-01

A flow-injection configuration based on a dual-phase gas-permeation system from a liquid donor to a gas acceptor stream with a thermistor flow-through detector is proposed for the direct analysis of the gas in the acceptor. This system was applied for the determination of carbon dioxide (in the form of carbonate) using the following chemical reaction: CO(2)(g)+2NH(3)(g)+H(2)O(g)=(NH(4))(2)CO(3)(s), with a linear response from 1x10(-3) to 50x10(-3) mol l(-1) of CO(3)(2-). Carbon dioxide was produced in the liquid donor and permeated into the gaseous acceptor stream of air/water vapor. The detection limit is 1x10(-3) mol l(-1) of carbonate, and a sampling frequency of 60 h(-1) is achieved with a relative standard deviation of 4.1% for replicate injections. The dual-phase gas-permeation flow-injection manifold, along with the membrane and phase separations, as well as the chemical reaction, provides enhanced selectivity when compared with the system employing a liquid acceptor stream, as serious interferents in this system, for instance, acetate and formate, among others, do not interfere in the proposed system.
Three-dimensional simulation of flow and combustion for pulverised coal injection

Energy Technology Data Exchange (ETDEWEB)

Guo, B.Y.; Zulli, P.; Rogers, H.; Mathieson, J.G.; Yu, A.B. [BlueScope Steel Research, Port Kembla, NSW (Australia)

2005-07-01

A three-dimensional numerical model of pulverised coal injection has been developed for simulating coal flow and combustion in the tuyere and raceway of a blast furnace. The model has been used to simulate previously reported combustion tests, which feature an inclined co-axial lance with an annular cooling gas. The predicted coal burnout agrees well with that measured for three coals with volatile contents and particle size ranging between 20.2-36.4% and particle sizes 1-200 {mu}m. Many important phenomena including flow asymmetry, recirculating flow and particle dispersion in the combustion chamber have been predicted. The current model can reproduce the experimental observations including the effects on burnout of coal flowrate and the introduction of methane for lance cooling.
Optimized and validated flow-injection spectrophotometric analysis of topiramate, piracetam and levetiracetam in pharmaceutical formulations.

Science.gov (United States)

Hadad, Ghada M; Abdel-Salam, Randa A; Emara, Samy

2011-12-01

Application of a sensitive and rapid flow injection analysis (FIA) method for determination of topiramate, piracetam, and levetiracetam in pharmaceutical formulations has been investigated. The method is based on the reaction with ortho-phtalaldehyde and 2-mercaptoethanol in a basic buffer and measurement of absorbance at 295 nm under flow conditions. Variables affecting the determination such as sample injection volume, pH, ionic strength, reagent concentrations, flow rate of reagent and other FIA parameters were optimized to produce the most sensitive and reproducible results using a quarter-fraction factorial design, for five factors at two levels. Also, the method has been optimized and fully validated in terms of linearity and range, limit of detection and quantitation, precision, selectivity and accuracy. The method was successfully applied to the analysis of pharmaceutical preparations.
Numerical simulation of effects of a non-ionized fluid injection and suction on the MHD flow in a circular channel

International Nuclear Information System (INIS)

Rahimi Eosboee, M.; Pourmahmoud, N.; Mirzaie, I.; Mohajeri Khameneh, P.; Majidyfar, S.

2012-01-01

Control of a fluid flow velocity profile by injection and suction of a non-ionized fluid in presence of a uniform steady magnetic field has important technical applications. In this paper, the unsteady incompressible and viscous conducting fluid flow has been investigated in a circular channel. The channel walls are assumed to be non-conducting and porous. They are subjected to a uniform steady magnetic field which is perpendicular to the axis of channel, then and suction and injection are applied at the walls. The well known equations of Magnetohydrodynamics are governed to the motion of an electrically conducting fluid flow that is subjected to magnetic field. The numerical solution is carried out by finite difference approach. The results of present numerical simulation shown that the flow injection and suction through the wall can be controlled effectively, the main flow in channel especially in industrial purposes. The results are obtained for different values of the injected and sucked non-ionized flow rate and the effect of Hartman number on the velocity profile is investigated. Finally, a good agreement is seen between the presented results and the corresponding data of finite element method.
Dispersion-convolution model for simulating peaks in a flow injection system.

Science.gov (United States)

Pai, Su-Cheng; Lai, Yee-Hwong; Chiao, Ling-Yun; Yu, Tiing

2007-01-12

A dispersion-convolution model is proposed for simulating peak shapes in a single-line flow injection system. It is based on the assumption that an injected sample plug is expanded due to a "bulk" dispersion mechanism along the length coordinate, and that after traveling over a distance or a period of time, the sample zone will develop into a Gaussian-like distribution. This spatial pattern is further transformed to a temporal coordinate by a convolution process, and finally a temporal peak image is generated. The feasibility of the proposed model has been examined by experiments with various coil lengths, sample sizes and pumping rates. An empirical dispersion coefficient (D*) can be estimated by using the observed peak position, height and area (tp*, h* and At*) from a recorder. An empirical temporal shift (Phi*) can be further approximated by Phi*=D*/u2, which becomes an important parameter in the restoration of experimental peaks. Also, the dispersion coefficient can be expressed as a second-order polynomial function of the pumping rate Q, for which D*(Q)=delta0+delta1Q+delta2Q2. The optimal dispersion occurs at a pumping rate of Qopt=sqrt[delta0/delta2]. This explains the interesting "Nike-swoosh" relationship between the peak height and pumping rate. The excellent coherence of theoretical and experimental peak shapes confirms that the temporal distortion effect is the dominating reason to explain the peak asymmetry in flow injection analysis.
Modelling of limestone injection for SO2 capture in a coal fired utility boiler

International Nuclear Information System (INIS)

Kovacik, G.J.; Reid, K.; McDonald, M.M.; Knill, K.

1997-01-01

A computer model was developed for simulating furnace sorbent injection for SO 2 capture in a full scale utility boiler using TASCFlow TM computational fluid dynamics (CFD) software. The model makes use of a computational grid of the superheater section of a tangentially fired utility boiler. The computer simulations are three dimensional so that the temperature and residence time distribution in the boiler could be realistically represented. Results of calculations of simulated sulphur capture performance of limestone injection in a typical utility boiler operation were presented
Theoretical Study on the Flow of Refilling Stage in a Safety Injection Tank

Energy Technology Data Exchange (ETDEWEB)

Park, Jun Sang [Halla Univ. Daejeon (Korea, Republic of)

2017-10-15

In this study, a theoretical analysis was performed to the flow of refilling stage in a safety injection tank, which is the core cooling system of nuclear power plant in an emergency. A theoretical model was proposed with a nonlinear governing equation defining on the flow of the refilling process of the coolant. Utilizing the Taylor-series expansion, the 1st - order approximation flow equation was obtained, along with its analytic solution of closed type, which could predict accurately the variations of free surface height and flow rate of the coolant. The availability of theoretical result was confirmed by comparing with previous experimental results.
Wavelet transform for the evaluation of peak intensities in flow-injection analysis

NARCIS (Netherlands)

Bos, M.; Hoogendam, E.

1992-01-01

The application of the wavelet transform in the determination of peak intensities in flow-injection analysis was studied with regard to its properties of minimizing the effects of noise and baseline drift. The results indicate that for white noise and a favourable peak shape a signal-to-noise ratio
Wavelett transform for the evaluation of peak intensities in flow-injection analysis

NARCIS (Netherlands)

Bos, M.; Hoogendam, E.; Hoogendam, E.

1992-01-01

The application of the wavelet transform in the determination of peak intensities in flow-injection analysis was studied with regard to its properties of minimizing the effects of noise and baseline drift. The results indicate that for white noise and a favourable peak shape a signal-to-noise ratio
Kalker's algorithm Fastsim solves tangential contact problems with slip-dependent friction and friction anisotropy

Science.gov (United States)

Piotrowski, J.

2010-07-01

This paper presents two extensions of Kalker's algorithm Fastsim of the simplified theory of rolling contact. The first extension is for solving tangential contact problems with the coefficient of friction depending on slip velocity. Two friction laws have been considered: with and without recuperation of the static friction. According to the tribological hypothesis for metallic bodies shear failure, the friction law without recuperation of static friction is more suitable for wheel and rail than the other one. Sample results present local quantities inside the contact area (division to slip and adhesion, traction) as well as global ones (creep forces as functions of creepages and rolling velocity). For the coefficient of friction diminishing with slip, the creep forces decay after reaching the maximum and they depend on the rolling velocity. The second extension is for solving tangential contact problems with friction anisotropy characterised by a convex set of the permissible tangential tractions. The effect of the anisotropy has been shown on examples of rolling without spin and in the presence of pure spin for the elliptical set. The friction anisotropy influences tangential tractions and creep forces. Sample results present local and global quantities. Both extensions have been described with the same language of formulation and they may be merged into one, joint algorithm.
Surface representations of two- and three-dimensional fluid flow topology

Science.gov (United States)

Helman, James L.; Hesselink, Lambertus

1990-01-01

We discuss our work using critical point analysis to generate representations of the vector field topology of numerical flow data sets. Critical points are located and characterized in a two-dimensional domain, which may be either a two-dimensional flow field or the tangential velocity field near a three-dimensional body. Tangent curves are then integrated out along the principal directions of certain classes of critical points. The points and curves are linked to form a skeleton representing the two-dimensional vector field topology. When generated from the tangential velocity field near a body in a three-dimensional flow, the skeleton includes the critical points and curves which provide a basis for analyzing the three-dimensional structure of the flow separation. The points along the separation curves in the skeleton are used to start tangent curve integrations to generate surfaces representing the topology of the associated flow separations.
A dilute-and-shoot flow-injection tandem mass spectrometry method for quantification of phenobarbital in urine.

Science.gov (United States)

Alagandula, Ravali; Zhou, Xiang; Guo, Baochuan

2017-01-15

Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is the gold standard of urine drug testing. However, current LC-based methods are time consuming, limiting the throughput of MS-based testing and increasing the cost. This is particularly problematic for quantification of drugs such as phenobarbital, which is often analyzed in a separate run because they must be negatively ionized. This study examined the feasibility of using a dilute-and-shoot flow-injection method without LC separation to quantify drugs with phenobarbital as a model system. Briefly, a urine sample containing phenobarbital was first diluted by 10 times, followed by flow injection of the diluted sample to mass spectrometer. Quantification and detection of phenobarbital were achieved by an electrospray negative ionization MS/MS system operated in the multiple reaction monitoring (MRM) mode with the stable-isotope-labeled drug as internal standard. The dilute-and-shoot flow-injection method developed was linear with a dynamic range of 50-2000 ng/mL of phenobarbital and correlation coefficient > 0.9996. The coefficients of variation and relative errors for intra- and inter-assays at four quality control (QC) levels (50, 125, 445 and 1600 ng/mL) were 3.0% and 5.0%, respectively. The total run time to quantify one sample was 2 min, and the sensitivity and specificity of the method did not deteriorate even after 1200 consecutive injections. Our method can accurately and robustly quantify phenobarbital in urine without LC separation. Because of its 2 min run time, the method can process 720 samples per day. This feasibility study shows that the dilute-and-shoot flow-injection method can be a general way for fast analysis of drugs in urine. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
A novel approach for determination of free fatty acids in vegetable oils by a flow injection system with manual injection.

Science.gov (United States)

Ayyildiz, H Filiz; Kara, Huseyin; Sherazi, S T H

2011-12-01

A non-aqueous flow injection method for determining free fatty acid (FFA) content in corn and sunflower oil samples was developed. A single-line manifold system was built by modification of an HPLC for flow injection analysis (FIA). Without pre-treatment, oil samples were injected into a n-propanol solution containing KOH and phenolphthalein (PHP). The main parameters, such as flow rate of carrier phase, length, geometry, inner diameters of the coils and reagent concentration were all optimized. The proposed FIA method was validated for precision, accuracy, linear region, limit of detection (LOD) and limit of quantification (LOQ). The intra- and inter-day measurements of the precision of the method were found to be within the limits of acceptance criteria (RSD analyst. The linear concentration range was calculated as 0.09-1.50 and 0.07-1.40 FFA% for corn and sunflower oils, correspondingly. The LOD and LOQ were found to be 7.53 × 10(-4)-2.28 × 10(-3) oleic acid % and 7.11 × 10(-4)-2.23 × 10(-3) oleic acid % for corn and sunflower oils, respectively. The results were compared with those obtained by the AOCS (Ca-5a-40) method using statistical t and F tests, and a significant difference was not observed between the methods at a 95% confidence level. The proposed method is suitable for quality control of routine applications due to its simplicity, high sample throughput, and economy of solvents and sample, offering considerable promise as a low cost analytical system that needs minimum human intervention over long periods of time.
Numerical simulation of the gas-solid flow in a square circulating fluidized bed with secondary air injection

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhengyang [Harbin Institute of Technology, Harbin (China). Post-doctor Station of Civil Engineering; Harbin Institute of Technology, Harbin (China). Combustion Engineering Research Inst.; Sun, Shaozeng; Zhao, Ningbo; Wu, Shaohua [Harbin Institute of Technology, Harbin (China). Combustion Engineering Research Inst.; Tan, Yufei [Harbin Institute of Technology, Harbin (China). School of Municipal and Environmental Engineering

2013-07-01

The dynamic behavior of gas-solid flow in an experimental square circulating fluidized bed setup (0.25 m x 0.25 m x 6.07 m) is predicted with numerical simulation based on the theory of Euler-Euler gas-solid two-phase flow and the kinetic theory of granular flows. The simulation includes the operation cases with secondary injection and without air-staging. The pressure drop profile, local solids concentration and particle velocity was compared with experimental results. Both simulation and experimental results show that solids concentration increases significantly below the secondary air injection ports when air-staging is adopted. Furthermore, the flow asymmetry in the solid entrance region of the bed was investigated based on the particle concentration/velocity profile. The simulation results are in agreement with the experimental results qualitatively.
Minicolumn field preconcentration and flow-injection flame atomic absorption spectrometric determination of cadmium in seawater

International Nuclear Information System (INIS)

Yebra-Biurrun, M.C.; Moreno-Cid, A.; Puig, L.

2004-01-01

A simple method for the continuous field preconcentration of trace dissolved cadmium in seawater samples has been developed based on the minicolumn field sampling technique. For this purpose, minicolumns containing Chelite P (aminomethylphosphonic groups) were connected to a field flow preconcentration system (FFPS). Once in the laboratory, these minicolumns are sequentially inserted into a flow-injection system for on-line cadmium elution and detection by flame atomic absorption spectrometry. Factorial designs have been used to optimise the FFPS and the flow-injection elution process. Six experimental variables were optimised: sample pH, sample flow-rate, eluent concentration, eluent volume, eluent flow-rate and minicolumn diameter. The detection limit (3F) of the procedure was 2.7 ng l -1 for a sample volume of 300 ml. The precision (expressed as relative standard deviation) for 11 independent determinations was 0.5-9.4% for cadmium solutions of 10-300 ng l -1 . Analysis of certified reference materials (SLEW-3 and NASS-5) showed good agreement with the certified values. This procedure has been successfully applied to the determination of cadmium in seawater samples from Galicia (Spain)

Numerical simulation of flow characteristics of lean jet to cross-flow in safety injection of reactor cooling system

International Nuclear Information System (INIS)

Wang Haijun; He Huining; Luo Yushan; Wang Weishu

2011-01-01

In the present work, a numerical simulation was performed to study the flow characteristics of lean jet to cross flow in a main tube in the safety injection of reactor cooling system. The influence scope and mixing characteristics of the confined lean jet in cross-flow were studied. It can be concluded that three basic flow regimes are marked, namely the attached lean jet, lift-off lean jet and impinging lean jet. The velocity ratio V R is the key factor in the flow state. The depth and region of jet to main flow are enhanced with the increase of the velocity ratio. The jet flow penetrates through the main flow with the increase of the velocity ratio. At higher velocity ratio, the jet flow strikes the main flow bottom and circumfluence happens in upriver of main flow. The vortex flow characteristics dominate the flow near region of jet to cross-flow and the mixture of jet to cross-flow. At different velocity ratio V R , the vortex grows from the same displacement, but the vortex type and the vortex is different. At higher velocity ratio, the vortex develops fleetly, wears off sharp and dies out sharp. The study is very important to the heat transfer experiments of cross-flow jet and thermal stress analysis in the designs of nuclear engineering. (authors)
A study on nozzle flow and spray characteristics of piezo injector for next generation high response injection

International Nuclear Information System (INIS)

Lee, Jin Wook; Min, Kyoung Doug

2006-01-01

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(Volume Of Fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response in a piezo-driven injector were reflected to spray development in agreement with the experimental spray images
[Studies on a sequential injection renewable surface reflectance spectrophotometric system using a microchip flow cell].

Science.gov (United States)

Wang, Jian-ya; Fang, Zhao-lun

2002-02-01

A microchip flow cell was developed for flow injection renewable surface assay by reflectance spectrophotometry. The flow cell was coupled to a sequential injection system and optical fiber photometric detection system. The flow cell featured a three-layer structure. The flow channel was cut into a silicone rubber membrance which formed the middle layer, and a porous filter was inlayed across a widened section of the channel to trap microbeads introduced into the flow cell. The area of the detection window of the flow cell was approximately 3.6 mm2, the volume of the bead trapped in the flow cell was 2.2 microL, the depth of the bead layer was 600 microns. A multistrand bifurcated optical fiber was coupled with incident light, detector and flow cell. The chromogenic reaction of Cr(VI) with 1,5-diphenylcarbohydrazide (DPC) which was adsorbed on trapped Polysorb C-18 beads was used as a model reaction to optimize the flow cell design and the experimental system. The reflectance of the renewable reaction surface was monitored at 540 nm. With 100 microL sample loaded and 1.0 mL.min-1 carrier flow rate, the linear response range was 0-0.6 microgram.mL-1 Cr(VI). A detection limit (3 sigma) of 6 ng.mL-1, precision of 1.5% RSD(n = 11), and a throughput of 64 samples per hour were achieved. Considerations in system and flow cell design, the influence of depth of the bead layer, weight of beads used, and the flow rates of carrier stream on the performance were discussed.
Magnetohydrodynamics effect on three-dimensional viscous incompressible flow between two horizontal parallel porous plates and heat transfer with periodic injection/suction

Directory of Open Access Journals (Sweden)

R. C. Chaudhary

2004-11-01

Full Text Available We investigate the hydromagnetic effect on viscous incompressible flow between two horizontal parallel porous flat plates with transverse sinusoidal injection of the fluid at the stationary plate and its corresponding removal by periodic suction through the plate in uniform motion. The flow becomes three dimensional due to this injection/suction velocity. Approximate solutions are obtained for the flow field, the pressure, the skin-friction, the temperature field, and the rate of heat transfer. The dependence of solution on M (Hartmann number and ÃŽÂ» (injection/suction is investigated by the graphs and tables.
A microfabricated electroosmotic pump coupled to a gas-diffusion microchip for flow injection analysis of ammonia

International Nuclear Information System (INIS)

Zhu, Zaifang; Lu, Joann J.; Liu, Shaorong; Almeida, M. Inês G. S.; Kolev, Spas D.; Pu, Qiaosheng

2015-01-01

We have microfabricated two functional components toward developing a microchip flow injection analysis (FIA) system, i.e., an open-channel electroosmotic pump and a gas-diffusion chip, consisting of two microfabricated glass wafers and a porous polytetrafluoroethylene membrane. This is the first application of gas-diffusion separation in a microchip FIA system. To demonstrate the feasibility of using these two components for performing gas-diffusion FIA, we have incorporated them together with a regular FIA injection valve and a capillary electrophoresis absorbance detector in a flow injection system for determination of ammonia in environmental water samples. This system has a limit of detection of 0.10 mg L −1 NH 3 , with a good repeatability (relative standard deviation of less than 5 % for 4.0 mg L −1 NH 3 ). Parameters affecting its performance are also discussed. (author)
NSTX Tangential Divertor Camera

International Nuclear Information System (INIS)

Roquemore, A.L.; Ted Biewer; Johnson, D.; Zweben, S.J.; Nobuhiro Nishino; Soukhanovskii, V.A.

2004-01-01

Strong magnetic field shear around the divertor x-point is numerically predicted to lead to strong spatial asymmetries in turbulence driven particle fluxes. To visualize the turbulence and associated impurity line emission near the lower x-point region, a new tangential observation port has been recently installed on NSTX. A reentrant sapphire window with a moveable in-vessel mirror images the divertor region from the center stack out to R 80 cm and views the x-point for most plasma configurations. A coherent fiber optic bundle transmits the image through a remotely selected filter to a fast camera, for example a 40500 frames/sec Photron CCD camera. A gas puffer located in the lower inboard divertor will localize the turbulence in the region near the x-point. Edge fluid and turbulent codes UEDGE and BOUT will be used to interpret impurity and deuterium emission fluctuation measurements in the divertor
Exact solution for flow in a porous pipe with unsteady wall suction and/or injection

Science.gov (United States)

Tsangaris, S.; Kondaxakis, D.; Vlachakis, N. W.

2007-10-01

This paper presents an extension of the exact solution of the steady laminar axisymmetric flow in a straight pipe of circular cross section with porous wall, given by R.M. Terrill, to the case of unsteady wall injection and/or suction. The cases of the pulsating parabolic profile and of the developed pulsating flow are investigated as examples. The pulsating flow in porous ducts has many applications in biomedical engineering and in other engineering areas.
Rapid determination of 99Tc in environmental samples by high resolution ICP-MS coupled with on-line flow injection system

International Nuclear Information System (INIS)

Kim, C.K.; Kim, C.S.; Rho, B.H.; Lee, J.I.

2002-01-01

High resolution inductively coupled plasma mass spectrometry coupled with an on-line flow injection system (FI-HR-ICP-MS) was applied to determine the ultra-trace level 99 Tc in soil. The flow injection system (PrepLab TM ) was composed of two TEVA-Spec R resins, reduced remarkably the sample amounts and the analysis time, compared to the conventional analytical methods. In the flow injection system, Mo and Ru were sufficiently eliminated by using the flow injection system, with the decontamination factors of 1.6 x 10 4 and 9.9 x 10 5 , respectively. With the present method, it was possible to determine ultra-low level of 99 Tc in 3∼6 soil at 3-5 hours of analysis time per sample. The relative standard deviation for each sample was less than 4%. The detection limits for 99 Tc was 85 fg x ml -1 (0.05 mBq x ml -1 ), which was calculated from the three times standard deviation of the count rate of the blank. (author)
Acoustic streaming in simplified liquid rocket engines with transverse mode oscillations

Science.gov (United States)

Fischbach, Sean R.; Flandro, Gary A.; Majdalani, Joseph

2010-06-01

This study considers a simplified model of a liquid rocket engine in which uniform injection is imposed at the faceplate. The corresponding cylindrical chamber has a small length-to-diameter ratio with respect to solid and hybrid rockets. Given their low chamber aspect ratios, liquid thrust engines are known to experience severe tangential and radial oscillation modes more often than longitudinal ones. In order to model this behavior, tangential and radial waves are superimposed onto a basic mean-flow model that consists of a steady, uniform axial velocity throughout the chamber. Using perturbation tools, both potential and viscous flow equations are then linearized in the pressure wave amplitude and solved to the second order. The effects of the headwall Mach number are leveraged as well. While the potential flow analysis does not predict any acoustic streaming effects, the viscous solution carried out to the second order gives rise to steady secondary flow patterns near the headwall. These axisymmetric, steady contributions to the tangential and radial traveling waves are induced by the convective flow motion through interactions with inertial and viscous forces. We find that suppressing either the convective terms or viscosity at the headwall leads to spurious solutions that are free from streaming. In our problem, streaming is initiated at the headwall, within the boundary layer, and then extends throughout the chamber. We find that nonlinear streaming effects of tangential and radial waves act to alter the outer solution inside a cylinder with headwall injection. As a result of streaming, the radial wave velocities are intensified in one-half of the domain and reduced in the opposite half at any instant of time. Similarly, the tangential waves are either enhanced or weakened in two opposing sectors that are at 90° angle to the radial velocity counterparts. The second-order viscous solution that we obtain clearly displays both an oscillating and a steady flow
Flow Injection and Atomic Absorption Spectrometry - An Effective and Attractive Analytical Chemical Combination

DEFF Research Database (Denmark)

Hansen, Elo Harald; Nielsen, Steffen

1998-01-01

One of the advantages of the flow injection (FI) concept is that it is compatible with virtually all detection techniques. Being a versatile vehicle for enhancing the performance of the individual detection devices, the most spectacular results have possibly been obtained in conjunction with atom...
AAO-CNTs electrode on microfluidic flow injection system for rapid iodide sensing.

Science.gov (United States)

Phokharatkul, Ditsayut; Karuwan, Chanpen; Lomas, Tanom; Nacapricha, Duangjai; Wisitsoraat, Anurat; Tuantranont, Adisorn

2011-06-15

In this work, carbon nanotubes (CNTs) nanoarrays in anodized aluminum oxide (AAO-CNTs) nanopore is integrated on a microfluidic flow injection system for in-channel electrochemical detection of iodide. The device was fabricated from PDMS (polydimethylsiloxane) microchannel bonded on glass substrates that contains three-electrode electrochemical system, including AAO-CNTs as a working electrode, silver as a reference electrode and platinum as an auxiliary electrode. Aluminum, stainless steel catalyst, silver and platinum layers were sputtered on the glass substrate through shadow masks. Aluminum layer was then anodized by two-step anodization process to form nanopore template. CNTs were then grown in AAO template by thermal chemical vapor deposition. The amperometric detection of iodide was performed in 500-μm-wide and 100-μm-deep microchannels on the microfluidic chip. The influences of flow rate, injection volume and detection potential on the current response were optimized. From experimental results, AAO-CNTs electrode on chip offers higher sensitivity and wider dynamic range than CNTs electrode with no AAO template. Copyright © 2011 Elsevier B.V. All rights reserved.
Stopped-flow injection method for determination of phosphate in soils and fertilisers

Directory of Open Access Journals (Sweden)

Jaroon Jakmunee

2008-02-01

Full Text Available A stopped-flow injection system for the determination of phosphate has been developed. It involves the phosphate-molybdate-ascorbic acid reactions in the molybdenum blue method. The system is controlled by a semi-automatic stopped-FI analyser with a light emitting diode (LED-colorimeter for monitoring the absorbance change relating to the concentration of a reaction product formed during the stopping period while the injected zone of a standard or sample is being in the flow cell. The slope of the FIAgram obtained is linearly proportional to the reaction rate, which depends on the phosphate concentration. Effects of concentration of reagents, viz. sodium molybdate, ascorbic acid and nitric acid, on the slope of the FIAgram were studied. The suitable concentration is 0.02 M, 0.25 %w/v and 0.15 M, respectively. A linear calibration graph in the range of 0.3-6.0 mg P L-1 was employed for the determination of phosphate in soil and fertiliser samples. The results obtained agree well with those from a standard spectrophotometric method.
The determination of uranium(VI) by flow-injection analysis

International Nuclear Information System (INIS)

Jones, E.A.

1985-01-01

A method is described for the direct determination of uranium(VI) in waste waters and acid leach liquors by use of a flow-injection procedure and spectrophotometric measurement with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (bromo-PADAP). The interference effects of several commonly occurring elements were studied. The calibration curve is linear over concentrations of uranium(VI) from 0,5 to 20 mg/1, and the precision obtained on a synthetic leach liquor was 0,019 (relative standard deviation). The procedure is rapid and convenient, and up to 40 samples can be analysed in an hour
Comparison of histologic margin status in low-grade cutaneous and subcutaneous canine mast cell tumours examined by radial and tangential sections.

Science.gov (United States)

Dores, C B; Milovancev, M; Russell, D S

2018-03-01

Radial sections are widely used to estimate adequacy of excision in canine cutaneous mast cell tumours (MCTs); however, this sectioning technique estimates only a small fraction of total margin circumference. This study aimed to compare histologic margin status in grade II/low grade MCTs sectioned using both radial and tangential sectioning techniques. A total of 43 circumferential margins were evaluated from 21 different tumours. Margins were first sectioned radially, followed by tangential sections. Tissues were examined by routine histopathology. Tangential margin status differed in 10 of 43 (23.3%) margins compared with their initial status on radial section. Of 39 margins, 9 (23.1%) categorized as histologic tumour-free margin (HTFM) >0 mm were positive on tangential sectioning. Tangential sections detected a significantly higher proportion of positive margins relative to radial sections (exact 2-tailed P-value = .0215). The HTFM was significantly longer in negative tangential margins than positive tangential margins (mean 10.1 vs 3.2 mm; P = .0008). A receiver operating characteristic curve comparing HTFM and tangentially negative margins found an area under the curve of 0.83 (95% confidence interval: 0.71-0.96). Although correct classification peaked at the sixth cut-point of HTFM ≥1 mm, radial sections still incorrectly classified 50% of margins as lacking tumour cells. Radial sections had 100% specificity for predicting negative tangential margins at a cut-point of 10.9 mm. These data indicate that for low grade MCTs, HTFMs >0 mm should not be considered completely excised, particularly when HTFM is <10.9 mm. This will inform future studies that use HTFM and overall excisional status as dependent variables in multivariable prognostic models. © 2017 John Wiley & Sons Ltd.
Numerical Simulation of Magnetic Nanoparticles Injection into Two–phase Flow in a Porous Medium

KAUST Repository

El-Amin, Mohamed; Saad, Ahmed M.; Sun, Shuyu; Salama, Amgad

2017-01-01

In this paper, the problem of magnetic nanoparticles injection into a water–oil two–phase flow under an external permanent magnetic field is investigated. The mathematical model of the problem under consideration has been developed. We treat
Quantum dots as chemiluminescence enhancers tested by sequential injection technique: Comparison of flow and flow-batch conditions

Energy Technology Data Exchange (ETDEWEB)

Sklenářová, Hana, E-mail: sklenarova@faf.cuni.cz [Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Analytical Chemistry, Hradec Králové (Czech Republic); Voráčová, Ivona [Institute of Analytical Chemistry of the CAS, v. v. i., Brno (Czech Republic); Chocholouš, Petr; Polášek, Miroslav [Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Analytical Chemistry, Hradec Králové (Czech Republic)

2017-04-15

The effect of 0.01–100 µmol L{sup −1} Quantum Dots (QDs) with different emission wavelengths (520–640 nm) and different surface modifications (mercaptopropionic, mercaptoundecanoic, thioglycolic acids and mercaptoethylamine) on permanganate-induced and luminol–hydrogen peroxide chemiluminescence (CL) was studied in detail by a sequential injection technique using a spiral detection flow cell and a flow-batch detection cell operated in flow and stop-flow modes. In permanganate CL system no significant enhancement of the CL signal was observed while for the luminol–hydrogen peroxide CL substantial increase (>100% and >90% with the spiral detection cell in flow and stop-flow modes, respectively) was attained for CdTe QDs. Enhancement exceeding 120% was observed for QDs with emissions at 520, 575 and 603 nm (sizes of 2.8 nm, 3.3 nm and 3.6 nm) using the flow-batch detection cell in the stop-flow mode. Pronounced effect was noted for surface modifications while mercaptoethylamine was the most efficient in CL enhancement compared to mercaptopropionic acid the most commonly applied coating. Significant difference between results obtained in flow and flow-batch conditions based on the entire kinetics of the extremely fast CL reaction was discussed. The increase of the CL signal was always accompanied by reduced lifetime of the CL emission thus application of QDs in flow techniques should be always coupled with the study of the CL lifetime.
Uncertainties in estimating heart doses from 2D-tangential breast cancer radiotherapy

DEFF Research Database (Denmark)

Laugaard Lorenzen, Ebbe; Brink, Carsten; Taylor, Carolyn W.

2016-01-01

BACKGROUND AND PURPOSE: We evaluated the accuracy of three methods of estimating radiation dose to the heart from two-dimensional tangential radiotherapy for breast cancer, as used in Denmark during 1982-2002. MATERIAL AND METHODS: Three tangential radiotherapy regimens were reconstructed using CT......-based planning scans for 40 patients with left-sided and 10 with right-sided breast cancer. Setup errors and organ motion were simulated using estimated uncertainties. For left-sided patients, mean heart dose was related to maximum heart distance in the medial field. RESULTS: For left-sided breast cancer, mean...... to the uncertainty of estimates based on individual CT-scans. For right-sided breast cancer patients, mean heart dose based on individual CT-scans was always
A study on nozzle flow and spray characteristics of piezo injector for next generation high response injection

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Wook [Korea Institue of Machinery and Materials, Daejeon (Korea, Republic of); Min, Kyoung Doug [Seoul National University, Seoul (Korea, Republic of)

2006-06-15

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(Volume Of Fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response in a piezo-driven injector were reflected to spray development in agreement with the experimental spray images.
Reduction of NOx emission in tangential fired - furnace by changing the, mode of operation

International Nuclear Information System (INIS)

Chudnovsky, B.; Talanker, A.; Levin, L.; Kahana, S

1998-01-01

The present work analyses tile results of tests on 575 MW units with tangential firing furnace arrangement in sub-stoichiometric combustion. Tangential firing provides good conditions for implementing sub-stoichiometric combustion owing to the delivery scheme of pulverized coal and air. The furnace was tested in several different modes of operation (Over Fire Air, Bunkers Out Of Service, Excess air, Tilt etc.) to achieve low cost NOx reduction. Actual performance data are presented based on experiments made on lEC's boiler in M.D. 'B' power station
Start-up assist by magnetized plasma flow injection in TPE-RX reversed-field pinch

Energy Technology Data Exchange (ETDEWEB)

Asai, T. [College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan)]. E-mail: asai@phys.cst.nihon-u.ac.jp; Nagata, M. [Graduate School of Engineering, University of Hyogo, Himeji (Japan); Koguchi, H. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Hirano, Y. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Sakakita, H. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Yambe, K. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Kiyama, S. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan)

2006-11-15

A reversed-field pinch (RFP) start-up assisted by a magnetized plasma flow injection was demonstrated for the first time on a TPE-RX machine. This sequence of experiments aimed to establish a new method of ionization, gas-fill and helicity injection in the start-up phase of an RFP. In this start-up method, magnetized and well-ionized plasma is formed by a magnetized coaxial plasma gun and injected into the torus chamber as an initial pre-ionized plasma for RFP formation. In the initial experiments, attenuated density pump-out and comparatively slow decay of the toroidal flux and plasma current were observed as evidence of its being an effective start-up method.

Tangential Biopsy Thickness versus Lesion Depth in Longitudinal Melanonychia: A Pilot Study

Directory of Open Access Journals (Sweden)

Nilton Di Chiacchio

2012-01-01

Full Text Available Longitudinal melanonychia can be caused by melanocyte activation (hypermelanosis or proliferation (lentigo, nevus or melanoma. Histopathologic examination is mandatory for suspicious cases of melanomas. Tangential biopsy of the matrix is an elegant technique avoiding nail plate dystrophy, but it was unknown whether the depth of the sample obtained by this method is adequate for histopathologic diagnosis. Twenty-two patients with longitudinal melanonychia striata were submitted to tangential matrix biopsies described by Haneke. The tissue was stained with hematoxylin-eosin and the specimens were measured at 3 distinct points according to the total thickness: largest (A, intermediate (B and narrowest (C then divided into 4 groups according to the histopathologic diagnosis (G1: hypermelanosis; G2: lentigos; G3: nevus; G4: melanoma. The lesions were measured using the same method. The mean specimen/lesion thickness measure values for each group was: G1: 0,59/0,10 mm, G2: 0,67/0,08 mm, G3: 0,52/0,05 mm, G4: 0,58/0,10 mm. The general average thickness for all the specimens/lesions was 0,59/0,08 mm. We concluded that the tangential excision, for longitudinal melanonychia, provides an adequate material for histopathological diagnosis.
The quality assessment of radial and tangential neutron radiography beamlines of TRR

International Nuclear Information System (INIS)

Dastjerdi, M.H. Choopan; Movafeghi, A.; Khalafi, H.; Kasesaz, Y.

2017-01-01

To achieve a quality neutron radiographic image in a relatively short exposure time, the neutron radiography beam must be of good quality and relatively high neutron flux. Characterization of a neutron radiography beam, such as determination of the image quality and the neutron flux, is vital for producing quality radiographic images and also provides a means to compare the quality of different neutron radiography facilities. This paper provides a characterization of the radial and tangential neutron radiography beamlines at the Tehran research reactor. This work includes determination of the facilities category according to the American Society for Testing and Materials (ASTM) standards, and also uses the gold foils to determine the neutron beam flux. The radial neutron beam is a Category I neutron radiography facility, the highest possible quality level according to the ASTM. The tangential beam is a Category IV neutron radiography facility. Gold foil activation experiments show that the measured neutron flux for radial beamline with length-to-diameter ratio (L/D) =150 is 6.1× 10 6 n cm −2 s −1 and for tangential beamline with (L/D)=115 is 2.4× 10 4 n cm −2 s −1 .
The Optimisation of Processing Condition for Injected Mould Polypropylene-Nanoclay-Gigantochloa Scortechinii based on Melt Flow Index

Science.gov (United States)

Othman, M. H.; Rosli, M. S.; Hasan, S.; Amin, A. M.; Hashim, M. Y.; Marwah, O. M. F.; Amin, S. Y. M.

2018-03-01

The fundamental knowledge of flow behaviour is essential in producing various plastic parts injection moulding process. Moreover, the adaptation of advanced polymer-nanocomposites such as polypropylene-nanoclay with natural fibres, for instance Gigantochloa Scortechinii may boost up the mechanical properties of the parts. Therefore, this project was proposed with the objective to optimise the processing condition of injected mould polypropylene-nanoclay-Gigantochloa Scortechini fibres based on the flow behaviour, which was melt flow index. At first, Gigantochloa Scortechinii fibres have to be preheated at temperature 120°C and then mixed with polypropylene, maleic anhydride modified polypropylene oligomers (PPgMA) and nanoclay by using Brabender Plastograph machine. Next, forms of pellets were produced from the samples by using Granulator machine for use in the injection moulding process. The design of experiments that was used in the injection moulding process was Taguchi Method Orthogonal Array -L934. Melt Flow Index (MF) was selected as the response. Based on the results, the value of MFI increased when the fiber content increase from 0% to 3%, which was 17.78 g/10min to 22.07 g/10min and decreased from 3% to 6%, which was 22.07 g/10min to 20.05 g/10min and 3%, which gives the highest value of MFI. Based on the signal to ratio analysis, the most influential parameter that affects the value of MFI was the melt temperature. The optimum parameter for 3% were 170°C melt temperature, 35% packing pressure, 30% screw speed and 3 second filling time.
Assessment of effect of intravitreal ranibizumab injection on the ocular blood flow in patients with neovascular age-related macular degeneration

Directory of Open Access Journals (Sweden)

V. V. Neroev

2014-07-01

Full Text Available Purpose: To evaluate the effect of intravitreal ranibizumab injection on the ocular blood flow in patients with neovascular agerelatedmacular degeneration (AMD.Methods: 35 patients with wet AMD undergone intravitreal 0.5 mg ranibizumab injection. Color Doppler Imaging (CDI and dopplerographywere used to measure hemodynamic parameters including the peak systolic velocity (Vsyst, cm / s, end-diastolic velocity (V diast, cm / s, and resistance index (RI of blood flow in the central retinal artery (CRA, the short posterior ciliary arteries (PCA, and the ophthalmic artery (OA. All patients were examined before and after injection on day 1‑7 and 30 day during the 3‑month follow up period.Results: Before intravitreal injection Vsyst was decreased in short PCA (p<0.05, RI in CRA and in short PCA significantly increased in comparison with normal index in same vessels. The peak systolic velocity in OA, in CRA and in short PCA was not significantly changed. After second injection resistance index in CRA and in short PCA was normalized.Conclusion: There was not impairment of ocular blood flow in retinal and choroidal after monthly intravitreal injection of ranibizumab during the 3‑month follow up period.
Assessment of effect of intravitreal ranibizumab injection on the ocular blood flow in patients with neovascular age-related macular degeneration

Directory of Open Access Journals (Sweden)

V. V. Neroev

2013-01-01

Full Text Available Purpose: To evaluate the effect of intravitreal ranibizumab injection on the ocular blood flow in patients with neovascular agerelatedmacular degeneration (AMD.Methods: 35 patients with wet AMD undergone intravitreal 0.5 mg ranibizumab injection. Color Doppler Imaging (CDI and dopplerographywere used to measure hemodynamic parameters including the peak systolic velocity (Vsyst, cm / s, end-diastolic velocity (V diast, cm / s, and resistance index (RI of blood flow in the central retinal artery (CRA, the short posterior ciliary arteries (PCA, and the ophthalmic artery (OA. All patients were examined before and after injection on day 1‑7 and 30 day during the 3‑month follow up period.Results: Before intravitreal injection Vsyst was decreased in short PCA (p<0.05, RI in CRA and in short PCA significantly increased in comparison with normal index in same vessels. The peak systolic velocity in OA, in CRA and in short PCA was not significantly changed. After second injection resistance index in CRA and in short PCA was normalized.Conclusion: There was not impairment of ocular blood flow in retinal and choroidal after monthly intravitreal injection of ranibizumab during the 3‑month follow up period.
Modelling and Simulation of Structural Deformation of Isothermal Subsurface Flow and Carbon Dioxide Injection

KAUST Repository

El-Amin, Mohamed; Negara, Ardiansyah; Salama, Amgad; Sun, Shuyu

2011-01-01

force term. The flux continuity condition is used at interfaces between different permeability layers of the heterogeneous medium. We analyze the vertical migration of a CO2 plume injected into a 2D layered reservoir. Analysis of distribution of flow
The determination, by flow-injection analysis, of iron, sulphate, silver and cadmium

International Nuclear Information System (INIS)

Jones, E.A.

1983-01-01

This report describes the spectrophotometric determination by flow-injection analysis including, where necessary, liquid-liquid extraction of iron with 1,10-phenanthroline; of sulphate by its catalytic effect on the methylthymol blue-zirconium reaction; of silver with bromopyrogallol red and 1,10-phenanthroline; and of cadmium with dithizone. Optimum conditions for each system are established, and sensitivities and ranges of determination are given
A rapid and accurate method for determining protein content in dairy products based on asynchronous-injection alternating merging zone flow-injection spectrophotometry.

Science.gov (United States)

Liang, Qin-Qin; Li, Yong-Sheng

2013-12-01

An accurate and rapid method and a system to determine protein content using asynchronous-injection alternating merging zone flow-injection spectrophotometry based on reaction between coomassie brilliant blue G250 (CBBG) and protein was established. Main merit of our approach is that it can avoid interferences of other nitric-compounds in samples, such as melamine and urea. Optimized conditions are as follows: Concentrations of CBBG, polyvinyl alcohol (PVA), NaCl and HCl are 150 mg/l, 30 mg/l, 0.1 mol/l and 1.0% (v/v), respectively; volumes of the sample and reagent are 150 μl and 30 μl, respectively; length of a reaction coil is 200 cm; total flow rate is 2.65 ml/min. The linear range of the method is 0.5-15 mg/l (BSA), its detection limit is 0.05 mg/l, relative standard deviation is less than 1.87% (n=11), and analytical speed is 60 samples per hour. Copyright © 2013 Elsevier Ltd. All rights reserved.
Flow-through solid-phase based optical sensor for the multisyringe flow injection trace determination of orthophosphate in waters with chemiluminescence detection

International Nuclear Information System (INIS)

Morais, Ines P.A.; Miro, Manuel; Manera, Matias; Estela, Jose Manuel; Cerda, Victor; Souto, M. Renata S.; Rangel, Antonio O.S.S.

2004-01-01

In this work, a novel flow-through solid-phase based chemiluminescence (CL) optical sensor is described for the trace determination of orthophosphate in waters exploiting the multisyringe flow injection analysis (MSFIA) concept with multicommutation. The proposed time-based injection flow system relies upon the in-line derivatisation of the analyte with ammonium molybdate in the presence of vanadate, and the transient immobilisation of the resulting heteropolyacid in a N-vinylpyrrolidone/divinylbenzene copolymer packed spiral shape flow-through cell located in front of the window of a photomultiplier tube. The simultaneous injection of well-defined slugs of luminol in alkaline medium and methanol solution towards the packed reactor is afterwards performed by proper switching of the solenoid valves. Then, the light emission from the luminol oxidation by the oxidant species retained onto the sorbent material is readily detected. At the same time, the generated molybdenum-blue compound is eluted by the minute amount of injected methanol, rendering the system prepared for a new measuring cycle. Therefore, the devised sensor enables the integration of the solid-phase CL reaction with elution and detection of the emitted light without the typical drawbacks of the molybdenum-blue based spectrophotometric procedures regarding the excess of molybdate anion, which causes high background signals due to its self-reduction. The noteworthy features of the developed CL-MSFIA system are the feasibility to accommodate reactions with different pH requirements and the ability to determine trace levels of orthophosphate in high silicate content samples (Si/P ratios up to 500). Under the optimised conditions, a dynamic linear range from 5 to 50 μg P l -1 for a 1.8 ml sample, repeatability better than 3.0% and a quantification limit of 4 μg P l -1 were attained. The flowing stream system handles 11 analysis h -1 and has been successfully applied to the determination of trace levels of
Advancement of In-Flight Alumina Powder Spheroidization Process with Water Droplet Injection Using a Small Power DC-RF Hybrid Plasma Flow System

Science.gov (United States)

Jang, Juyong; Takana, Hidemasa; Park, Sangkyu; Nishiyama, Hideya

2012-09-01

The correlation between plasma thermofluid characteristics and alumina powder spheroidization processes with water droplet injection using a small power DC-RF hybrid plasma flow system was experimentally clarified. Micro-sized water droplets with a low water flow rate were injected into the tail of thermal plasma flow so as not to disturb the plasma flow directly. Injected water droplets were vaporized in the thermal plasma flow and were transported upstream in the plasma flow to the torch by the backflow. After dissociation of water, the production of hydrogen was detected by the optical emission spectroscopy in the downstream RF plasma flow. The emission area of the DC plasma jet expanded and elongated in the vicinity of the RF coils. Additionally, the emission area of RF plasma flow enlarged and was visible as red emission in the downstream RF plasma flow in the vicinity below the RF coils due to hydrogen production. Therefore, the plasma flow mixed with produced hydrogen increased the plasma enthalpy and the highest spheroidization rate of 97% was obtained at a water flow rate of 15 Sm l/min and an atomizing gas flow rate of 8 S l/min using a small power DC-RF hybrid plasma flow system.
Numerical analysis of non-Newtonian rheology effect on hydrocyclone flow field

Directory of Open Access Journals (Sweden)

Lin Yang

2015-03-01

Full Text Available In view of the limitations of the existing Newton fluid effects on the vortex flow mechanism study, numerical analysis of non Newton fluid effects was presented. Using Reynolds stress turbulence model (RSM and mixed multiphase flow model (Mixture of FLUENT (fluid calculation software and combined with the constitutive equation of apparent viscosity of non-Newtonian fluid, the typical non-Newtonian fluid (drilling fluid, polymer flooding sewage and crude oil as medium and Newton flow field (water as medium were compared by quantitative analysis. Based on the research results of water, the effects of non-Newtonian rheology on the key parameters including the combined vortex motion index n and tangential velocity were analyzed. The study shows that: non-Newtonian rheology has a great effect on tangential velocity and n value, and tangential velocity decreases with non-Newtonian increasing. The three kinds of n values (constant segment are: 0.564(water, 0.769(polymer flooding sewage, 0.708(drilling fluid and their variation amplitudes are larger than Newtonian fluid. The same time, non-Newtonian rheology will lead to the phenomenon of turbulent drag reduction in the vortex flow field. Compared with the existing formula calculation results shown, the calculation result of non-Newtonian rheology is most consistent with the simulation result, and the original theory has large deviations. The study provides reference for theory research of non-Newtonian cyclone separation flow field.
Modelling and Simulation of Structural Deformation of Isothermal Subsurface Flow and Carbon Dioxide Injection

KAUST Repository

El-Amin, Mohamed

2011-05-15

Injection of CO2 in hydrocarbon reservoir has double benefit. On the one hand, it is a profitable method due to issues related to global warming, and on the other hand it is an effective mechanism to enhance hydrocarbon recovery. Such injection associates complex processes involving, e.g., solute transport of dissolved materials, in addition to local changes in density of the phases. Also, increasing carbon dioxide injection may cause a structural deformation of the medium, so it is important to include such effect into the model. The structural deformation modelling in carbon sequestration is important to evaluate the medium stability to avoid CO2 leakage to the atmosphere. On the other hand, geologic formation of the medium is usually heterogeneous and consists of several layers of different permeability. In this work we conduct numerical simulation of two-phase flow in a heterogeneous porous medium domain with dissolved solute transport as well as structural deformation effects. The solute transport of the dissolved component is described by concentration equation. The structural deformation for geomechanics is derived from a general local differential balance equation with neglecting the local mass balance of solid phase and the inertial force term. The flux continuity condition is used at interfaces between different permeability layers of the heterogeneous medium. We analyze the vertical migration of a CO2 plume injected into a 2D layered reservoir. Analysis of distribution of flow field components such as saturation, pressures, velocities, and CO2 concentration are presented.
Wall Thickness Measurement Of Insulated Pipe By Tangential Radiography Technique Using Ir 192

International Nuclear Information System (INIS)

Soedarjo

2000-01-01

Insulation pipe wall thickness by tangential radiography technique has been carried out using 41 Curie Iridium 192 source has activity for two carbon steel pipes. The outer diameter of the first pipe is 90 mm, wall thickness is 75.0 mm, source film film distance is 609.5 mm, source tangential point of insulation is 489.5 mm and exposure time 3 minute and 25 second. From the calculation, the first pipe thickness is found to be 12.54 mm and for the second pipe is 8.42 mm. The thickness is due to inaccuracy in reading the pipe thickness on radiography film and the geometry distortion radiation path
Validation/Uncertainty Quantification for Large Eddy Simulations of the heat flux in the Tangentially Fired Oxy-Coal Alstom Boiler Simulation Facility

Energy Technology Data Exchange (ETDEWEB)

Smith, P.J.; Eddings, E.G.; Ring, T.; Thornock, J.; Draper, T.; Isaac, B.; Rezeai, D.; Toth, P.; Wu, Y.; Kelly, K.

2014-08-01

The objective of this task is to produce predictive capability with quantified uncertainty bounds for the heat flux in commercial-scale, tangentially fired, oxy-coal boilers. Validation data came from the Alstom Boiler Simulation Facility (BSF) for tangentially fired, oxy-coal operation. This task brings together experimental data collected under Alstom’s DOE project for measuring oxy-firing performance parameters in the BSF with this University of Utah project for large eddy simulation (LES) and validation/uncertainty quantification (V/UQ). The Utah work includes V/UQ with measurements in the single-burner facility where advanced strategies for O2 injection can be more easily controlled and data more easily obtained. Highlights of the work include: • Simulations of Alstom’s 15 megawatt (MW) BSF, exploring the uncertainty in thermal boundary conditions. A V/UQ analysis showed consistency between experimental results and simulation results, identifying uncertainty bounds on the quantities of interest for this system (Subtask 9.1) • A simulation study of the University of Utah’s oxy-fuel combustor (OFC) focused on heat flux (Subtask 9.2). A V/UQ analysis was used to show consistency between experimental and simulation results. • Measurement of heat flux and temperature with new optical diagnostic techniques and comparison with conventional measurements (Subtask 9.3). Various optical diagnostics systems were created to provide experimental data to the simulation team. The final configuration utilized a mid-wave infrared (MWIR) camera to measure heat flux and temperature, which was synchronized with a high-speed, visible camera to utilize two-color pyrometry to measure temperature and soot concentration. • Collection of heat flux and temperature measurements in the University of Utah’s OFC for use is subtasks 9.2 and 9.3 (Subtask 9.4). Several replicates were carried to better assess the experimental error. Experiments were specifically designed for the
An investigation of flow properties of metal matrix composites suspensions for injection molding

International Nuclear Information System (INIS)

Ahmad, F.; Bevis, M.J.

1997-01-01

Flow properties of metal matrix composites suspensions have significant effects on the fibre orientation during mould filling. The results presented in this paper relate to the flow properties of aluminium powder and glass fibres compounded into a sacrificial thermoplastics binder. For this purpose, a range of aluminium compounds and aluminium composite suspensions were investigated over a wide shear rate range expected to occur during injection mould process. Aluminium composites wee prepared by substituting glass fibres for aluminium in aluminium compound. Aluminium composite containing a maximum critical volume fraction of fibres which did not exhibit an increase n viscosity was determined. The effect of temperature on the flow behaviour of aluminium composite was also investigated. (author)
Purification of monoclonal antibodies from clarified cell culture fluid using Protein A capture continuous countercurrent tangential chromatography.

Science.gov (United States)

Dutta, Amit K; Tran, Travis; Napadensky, Boris; Teella, Achyuta; Brookhart, Gary; Ropp, Philip A; Zhang, Ada W; Tustian, Andrew D; Zydney, Andrew L; Shinkazh, Oleg

2015-11-10

Recent studies using simple model systems have demonstrated that continuous countercurrent tangential chromatography (CCTC) has the potential to overcome many of the limitations of conventional Protein A chromatography using packed columns. The objective of this work was to optimize and implement a CCTC system for monoclonal antibody purification from clarified Chinese Hamster Ovary (CHO) cell culture fluid using a commercial Protein A resin. Several improvements were introduced to the previous CCTC system including the use of retentate pumps to maintain stable resin concentrations in the flowing slurry, the elimination of a slurry holding tank to improve productivity, and the introduction of an "after binder" to the binding step to increase antibody recovery. A kinetic binding model was developed to estimate the required residence times in the multi-stage binding step to optimize yield and productivity. Data were obtained by purifying two commercial antibodies from two different manufactures, one with low titer (∼ 0.67 g/L) and one with high titer (∼ 6.9 g/L), demonstrating the versatility of the CCTC system. Host cell protein removal, antibody yields and purities were similar to those obtained with conventional column chromatography; however, the CCTC system showed much higher productivity. These results clearly demonstrate the capabilities of continuous countercurrent tangential chromatography for the commercial purification of monoclonal antibody products. Copyright © 2015 Elsevier B.V. All rights reserved.
Purification of monoclonal antibodies from clarified cell culture fluid using Protein A capture continuous countercurrent tangential chromatography

Science.gov (United States)

Dutta, Amit K.; Tran, Travis; Napadensky, Boris; Teella, Achyuta; Brookhart, Gary; Ropp, Philip A.; Zhang, Ada W.; Tustian, Andrew D.; Zydney, Andrew L.; Shinkazh, Oleg

2015-01-01

Recent studies using simple model systems have demonstrated that Continuous Countercurrent Tangential Chromatography (CCTC) has the potential to overcome many of the limitations of conventional Protein A chromatography using packed columns. The objective of this work was to optimize and implement a CCTC system for monoclonal antibody purification from clarified Chinese Hamster Ovary (CHO) cell culture fluid using a commercial Protein A resin. Several improvements were introduced to the previous CCTC system including the use of retentate pumps to maintain stable resin concentrations in the flowing slurry, the elimination of a slurry holding tank to improve productivity, and the introduction of an “after binder” to the binding step to increase antibody recovery. A kinetic binding model was developed to estimate the required residence times in the multi-stage binding step to optimize yield and productivity. Data were obtained by purifying two commercial antibodies from two different manufactures, one with low titer (~0.67 g/L) and one with high titer (~6.9 g/L), demonstrating the versatility of the CCTC system. Host cell protein removal, antibody yields and purities were similar to that obtained with conventional column chromatography; however, the CCTC system showed much higher productivity. These results clearly demonstrate the capabilities of continuous countercurrent tangential chromatography for the commercial purification of monoclonal antibody products. PMID:25747172
Three-dimensional analysis of internal flow characteristics in the injection nozzle tip of direct-injection diesel engines; Sanjigen suchi kaiseki ni yoru DI diesel kikan no nenryo funsha nozzle nai ryudo tokusei no kaimei

Energy Technology Data Exchange (ETDEWEB)

Ogawa, H; Matsui, Y; Kimura, S [Nissan Motor Co. Ltd. Tokyo (Japan)

1997-10-01

To reduce the exhaust emissions and fuel consumption of direct-injection diesel engines, it is essential to optimize the fuel injection equipment closely related to combustion and emission characteristics. In this study, three-dimensional computation has been applied to investigate the effects of the injection nozzle specifications (e.g., sac volume, round shape at the inlet of the nozzle hole) and needle tip deviation on internal flow characteristics. The computational results revealed that the effects of the nozzle specifications and needle tip deviation with a smaller needle lift on internal flow characteristics and a general approach to optimize the injection nozzle specifications were obtained. 3 refs., 10 figs., 1 tab.
Cold water injection nozzles

International Nuclear Information System (INIS)

Kura, Masaaki; Maeda, Masamitsu; Endo, Takio.

1979-01-01

Purpose: To inject cold water in a reactor without applying heat cycles to a reactor container and to the inner wall of a feedwater nozzle by securing a perforated plate at the outlet of the cold water injection nozzle. Constitution: A disc-like cap is secured to the final end of a return nozzle of a control rod drive. The cap prevents the flow of a high temperature water flowing downward in the reactor from entering into the nozzle. The cap is perforated with a plurality of bore holes for injecting cold water into the reactor. The cap is made to about 100 mm in thickness so that the cold water passing through the bore holes is heated by the heat conduction in the cap. Accordingly, the flow of high temperature water flowing downwardly in the reactor is inhibited by the cap from backward flowing into the nozzle. Moreover, the flow of the cold water in the nozzle is controlled and rectified when passed through the bore holes in the cap and then injected into the reactor. (Yoshino, Y.)
How Flow Injection Analysis (FIA) over the past 25 years has changed our way of performing chemical analyses

DEFF Research Database (Denmark)

Hansen, Elo Harald; Miró, Manuel

2007-01-01

Briefly looking back on the impact of flow injection analysis (FIA), as reflected in the rapid growth of publications in the scientific literature, and touching upon many of the novel and unique analytical chemical possibilities that FIA and its sequels, sequential injection analysis (SIA) and La...

Second-order Data by Flow Injection Analysis with Spectrophotometric Diode-array Detection and Incorporated Gel-filtration Chromatographic Column

DEFF Research Database (Denmark)

Bechmann, Iben Ellegaard

1997-01-01

A flow injection analysis (FIA) system furnished with a gel-filtration chromatographic column and with photodiode-array detection was used for the generation of second-order data. The system presented is a model system in which the analytes are blue dextran, potassium hexacyanoferrate(III) and he......A flow injection analysis (FIA) system furnished with a gel-filtration chromatographic column and with photodiode-array detection was used for the generation of second-order data. The system presented is a model system in which the analytes are blue dextran, potassium hexacyanoferrate...
The effect of saturation on resin flow in injection pultrusion: a preliminary numerical study

DEFF Research Database (Denmark)

Spangenberg, Jon; Larsen, Martin; R. Rodríguez, Rosa

. The implemented saturation and relative permeability curves are adopted from relationships presented in the literature. The results of the numerical model highlights the importance of accurately determining thesaturation curve when included in a numerical solver that is used to predict the resin flow in injection...
Assessing preferential flow by simultaneously injecting nanoparticle and chemical tracers

KAUST Repository

Subramanian, S. K.; Li, Yan; Cathles, L. M.

2013-01-01

The exact manner in which preferential (e.g., much faster than average) flow occurs in the subsurface through small fractures or permeable connected pathways of other kinds is important to many processes but is difficult to determine, because most chemical tracers diffuse quickly enough from small flow channels that they appear to move more uniformly through the rock than they actually do. We show how preferential flow can be assessed by injecting 2 to 5 nm carbon particles (C-Dots) and an inert KBr chemical tracer at different flow rates into a permeable core channel that is surrounded by a less permeable matrix in laboratory apparatus of three different designs. When the KBr tracer has a long enough transit through the system to diffuse into the matrix, but the C-Dot tracer does not, the C-Dot tracer arrives first and the KBr tracer later, and the separation measures the degree of preferential flow. Tracer sequestration in the matrix can be estimated with a Peclet number, and this is useful for experiment design. A model is used to determine the best fitting core and matrix dispersion parameters and refine estimates of the core and matrix porosities. Almost the same parameter values explain all experiments. The methods demonstrated in the laboratory can be applied to field tests. If nanoparticles can be designed that do not stick while flowing through the subsurface, the methods presented here could be used to determine the degree of fracture control in natural environments, and this capability would have very wide ranging value and applicability.
Flow distribution in the inlet plenum of steam generator

International Nuclear Information System (INIS)

Khadamakar, H.P.; Patwardhan, A.W.; Padmakumar, G.; Vaidyanathan, G.

2011-01-01

Highlights: → Various flow distribution devices have been studied to make the flow distribution uniform in axial as well as tangential direction. → Experiments were performed using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV). → CFD modeling has been carried out to give more insights. → Various flow distribution devices have been compared. - Abstract: The flow distribution in a 1/5th and 1/8th scale models of inlet plenum of steam generator (SG) has been studied by a combination of experiments and Computational Fluid Dynamics (CFD) simulations. The distribution of liquid sodium in the inlet plenum of the SG strongly affects the thermal as well as mechanical performance of the steam generator. Various flow distribution devices have been used to make the flow distribution uniform in axial as well as tangential direction in the window region. Experiments have been conducted to measure the radial velocity distribution using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV) under a variety of conditions. CFD modeling has been carried out for various configurations to give more insight into the flow distribution phenomena. The various flow distribution devices have been compared on the basis of a non-uniformity index parameter.
Combined tangential-normal vector elements for computing electric and magnetic fields

International Nuclear Information System (INIS)

Sachdev, S.; Cendes, Z.J.

1993-01-01

A direct method for computing electric and magnetic fields in two dimensions is developed. This method determines both the fields and fluxes directly from Maxwell's curl and divergence equations without introducing potential functions. This allows both the curl and the divergence of the field to be set independently in all elements. The technique is based on a new type of vector finite element that simultaneously interpolates to the tangential component of the electric or the magnetic field and the normal component of the electric or magnetic flux. Continuity conditions are imposed across element edges simply by setting like variables to be the same across element edges. This guarantees the continuity of the field and flux at the mid-point of each edge and that for all edges the average value of the tangential component of the field and of the normal component of the flux is identical
Determination of pH by flow-injection analysis and by fiber-optrode analysis

International Nuclear Information System (INIS)

Pia, S.H.; Waltman, D.P.; Hillman, D.C.

1988-07-01

Two new procedures for measuring pH were developed. The first measures pH colorimetrically using a proprietary indicator-dye mixture in a flow injection analysis (FIA) procedure. The second measures pH using a fiber-optic chemical sensor (FOCS) specifically developed for pH determinations. The FOCS method measures pH by monitoring the fluorescence of a fluorescein derivative bonded to the distal end of a fiber-optic cable called an optrade. The FIA method currently has a precision and accuracy of about + or - 0.2 pH units and can measure 100 samples/hour. The FOCS method has a precision of + or - 0.05-0.20 pH units and an accuracy of + or - 0.1 to 0.6 pH units. About 10 to 60 samples can be analyzed. The characteristics of the FOCS Method will vary significantly with individual optrodes. The experimental results indicate that either flow-injection analysis or fiber optic chemical sensor analysis could form the basis for an alternative to electrometric measurement of pH in certain circumstances
Intensity-modulated tangential beam irradiation of the intact breast

International Nuclear Information System (INIS)

Hong, L.; Hunt, M.; Chui, C.; Spirou, S.; Forster, K.; Lee, H.; Yahalom, J.; Kutcher, G.J.; McCormick, B.

1999-01-01

Purpose: To evaluate the potential benefits of intensity modulated tangential beams in the irradiation of the intact breast. Methods and Materials: Three-dimensional treatment planning was performed on five left and five right breasts using standard wedged and intensity modulated (IM) tangential beams. Optimal beam parameters were chosen using beams-eye-view display. For the standard plans, the optimal wedge angles were chosen based on dose distributions in the central plane calculated without inhomogeneity corrections, according to our standard protocol. Intensity-modulated plans were generated using an inverse planning algorithm and a standard set of target and critical structure optimization criteria. Plans were compared using multiple dose distributions and dose volume histograms for the planning target volume (PTV), ipsilateral lung, coronary arteries, and contralateral breast. Results: Significant improvements in the doses to critical structures were achieved using intensity modulation. Compared with a standard-wedged plan prescribed to 46 Gy, the dose from the IM plan encompassing 20% of the coronary artery region decreased by 25% (from 36 to 27 Gy) for patients treated to the left breast; the mean dose to the contralateral breast decreased by 42% (from 1.2 to 0.7 Gy); the ipsilateral lung volume receiving more than 46 Gy decreased by 30% (from 10% to 7%); the volume of surrounding soft tissue receiving more than 46 Gy decreased by 31% (from 48% to 33%). Dose homogeneity within the target volume improved greatest in the superior and inferior regions of the breast (approximately 8%), although some decrease in the medial and lateral high-dose regions (approximately 4%) was also observed. Conclusion: Intensity modulation with a standard tangential beam arrangement significantly reduces the dose to the coronary arteries, ipsilateral lung, contralateral breast, and surrounding soft tissues. Improvements in dose homogeneity throughout the target volume can also be
Fast cholesterol detection using flow injection microfluidic device with functionalized carbon nanotubes based electrochemical sensor.

Science.gov (United States)

Wisitsoraat, A; Sritongkham, P; Karuwan, C; Phokharatkul, D; Maturos, T; Tuantranont, A

2010-12-15

This work reports a new cholesterol detection scheme using functionalized carbon nanotube (CNT) electrode in a polydimethylsiloxane/glass based flow injection microfluidic chip. CNTs working, silver reference and platinum counter electrode layers were fabricated on the chip by sputtering and low temperature chemical vapor deposition methods. Cholesterol oxidase prepared in polyvinyl alcohol solution was immobilized on CNTs by in-channel flow technique. Cholesterol analysis based on flow injection chronoamperometric measurement was performed in 150-μm-wide and 150-μm-deep microchannels. Fast and sensitive real-time detection was achieved with high throughput of more than 60 samples per hour and small sample volume of 15 μl. The cholesterol sensor had a linear detection range between 50 and 400 mg/dl. In addition, low cross-sensitivities toward glucose, ascorbic acid, acetaminophen and uric acid were confirmed. The proposed system is promising for clinical diagnostics of cholesterol with high speed real-time detection capability, very low sample consumption, high sensitivity, low interference and good stability. Copyright © 2010 Elsevier B.V. All rights reserved.
Development of a flow method for the determination of phosphate in estuarine and freshwaters-Comparison of flow cells in spectrophotometric sequential injection analysis

International Nuclear Information System (INIS)

Mesquita, Raquel B.R.; Ferreira, M. Teresa S.O.B.; Toth, Ildiko V.; Bordalo, Adriano A.; McKelvie, Ian D.; Rangel, Antonio O.S.S.

2011-01-01

Highlights: → Sequential injection determination of phosphate in estuarine and freshwaters. → Alternative spectrophotometric flow cells are compared. → Minimization of schlieren effect was assessed. → Proposed method can cope with wide salinity ranges. → Multi-reflective cell shows clear advantages. - Abstract: A sequential injection system with dual analytical line was developed and applied in the comparison of two different detection systems viz; a conventional spectrophotometer with a commercial flow cell, and a multi-reflective flow cell coupled with a photometric detector under the same experimental conditions. The study was based on the spectrophotometric determination of phosphate using the molybdenum-blue chemistry. The two alternative flow cells were compared in terms of their response to variation of sample salinity, susceptibility to interferences and to refractive index changes. The developed method was applied to the determination of phosphate in natural waters (estuarine, river, well and ground waters). The achieved detection limit (0.007 μM PO 4 3- ) is consistent with the requirement of the target water samples, and a wide quantification range (0.024-9.5 μM) was achieved using both detection systems.
Development of a flow method for the determination of phosphate in estuarine and freshwaters-Comparison of flow cells in spectrophotometric sequential injection analysis

Energy Technology Data Exchange (ETDEWEB)

Mesquita, Raquel B.R. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); Ferreira, M. Teresa S.O.B. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Toth, Ildiko V. [REQUIMTE, Departamento de Quimica, Faculdade de Farmacia, Universidade de Porto, Rua Anibal Cunha, 164, 4050-047 Porto (Portugal); Bordalo, Adriano A. [Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); McKelvie, Ian D. [School of Chemistry, University of Melbourne, Victoria 3010 (Australia); Rangel, Antonio O.S.S., E-mail: aorangel@esb.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)

2011-09-02

Highlights: {yields} Sequential injection determination of phosphate in estuarine and freshwaters. {yields} Alternative spectrophotometric flow cells are compared. {yields} Minimization of schlieren effect was assessed. {yields} Proposed method can cope with wide salinity ranges. {yields} Multi-reflective cell shows clear advantages. - Abstract: A sequential injection system with dual analytical line was developed and applied in the comparison of two different detection systems viz; a conventional spectrophotometer with a commercial flow cell, and a multi-reflective flow cell coupled with a photometric detector under the same experimental conditions. The study was based on the spectrophotometric determination of phosphate using the molybdenum-blue chemistry. The two alternative flow cells were compared in terms of their response to variation of sample salinity, susceptibility to interferences and to refractive index changes. The developed method was applied to the determination of phosphate in natural waters (estuarine, river, well and ground waters). The achieved detection limit (0.007 {mu}M PO{sub 4}{sup 3-}) is consistent with the requirement of the target water samples, and a wide quantification range (0.024-9.5 {mu}M) was achieved using both detection systems.
GABA regulates the multidirectional tangential migration of GABAergic interneurons in living neonatal mice.

Directory of Open Access Journals (Sweden)

Hiroyuki Inada

Full Text Available Cortical GABAergic interneurons originate from ganglionic eminences and tangentially migrate into the cortical plate at early developmental stages. To elucidate the characteristics of this migration of GABAergic interneurons in living animals, we established an experimental design specialized for in vivo time-lapse imaging of the neocortex of neonate mice with two-photon laser-scanning microscopy. In vesicular GABA/glycine transporter (VGAT-Venus transgenic mice from birth (P0 through P3, we observed multidirectional tangential migration of genetically-defined GABAergic interneurons in the neocortical marginal zone. The properties of this migration, such as the motility rate (distance/hr, the direction moved, and the proportion of migrating neurons to stationary neurons, did not change through P0 to P3, although the density of GABAergic neurons at the marginal zone decreased with age. Thus, the characteristics of the tangential motility of individual GABAergic neurons remained constant in development. Pharmacological block of GABA(A receptors and of the Na⁺-K⁺-Cl⁻ cotransporters, and chelating intracellular Ca²⁺, all significantly reduced the motility rate in vivo. The motility rate and GABA content within the cortex of neonatal VGAT-Venus transgenic mice were significantly greater than those of GAD67-GFP knock-in mice, suggesting that extracellular GABA concentration could facilitate the multidirectional tangential migration. Indeed, diazepam applied to GAD67-GFP mice increased the motility rate substantially. In an in vitro neocortical slice preparation, we confirmed that GABA induced a NKCC sensitive depolarization of GABAergic interneurons in VGAT-Venus mice at P0-P3. Thus, activation of GABA(AR by ambient GABA depolarizes GABAergic interneurons, leading to an acceleration of their multidirectional motility in vivo.
Impact of setup variability on incidental lung irradiation during tangential breast treatment

International Nuclear Information System (INIS)

Carter, D.C.; Marks, L.B.; Bentel, G.B.

1995-01-01

Purpose: 1) To determine the variability in treatment setup during a 5 week course of tangential breast treatment. 2) To assess the relationship between the height of the lung shadow at the central axis (Central Lung Distance: CLD) on the tangential port film and the percent of total lung volume included within the tangential fields (to verify the previously reported result from Bornstein, et al, IJROBP 18:181, 90). 3) To determine the impact of the variabilities in treatment setup on the volume of lung that is incidentally included within the radiation fields. Methods: 1) 172 port films of tangential breast/chest wall fields were reviewed from 20 patients who received tangential beam treatment for breast cancer. All patients were immobilized in customized hemibody foam cradles during simulation and treatment. The CLD (height of the lung shadow at the central axis) seen on each of the port films was compared to the corresponding simulator film (correcting for differences in magnification) as an assessment of setup variability. Both inter and intrapatient differences were considered. 2) A three-dimensional dose calculation (reflecting lung density) was performed, and the percent of total lung volume within the field was compared to the CLD. 3) The three-dimensional dose calculation was repeated for selected patients with the location of the treatment beams modified to reflect typical setup variations, in order to assess the impact of this variability on the volume of lung irradiated. Results: 1) The CLD measured on the port films was within 3 mm of that prescribed on the simulator film in 43% ((74(172))) of the port films. The variation was 3-5 mm in 26 %, 5-10 mm in 25 % and > 10 mm in 6 %. The data are shown in Figure 1. 2) There was an excellent correlation found between the height of the lung shadow and the percent of total lung volume seen within the radiation field, (Figure 2), thus verifying the concept previously reported by Bornstein. 3) A 1 cm setup
Indirect flow injection determination of N-acetyl-L-cysteine using cerium(IV) and ferroin

International Nuclear Information System (INIS)

Vieira, Heberth Juliano; Fatibello-Filho, Orlando

2005-01-01

An indirect flow injection spectrophotometric procedure is proposed for the determination of N-acetyl-L-cysteine in pharmaceutical formulations. In this system, ferroin ([Fe(II)-(fen) 2 ] 2+ ) in excess, with a strong absorption at 500 nm, is oxidized by cerium(IV) yielding cerium(III) and [Fe(III)-(fen) 2 ] 3+ (colorless), thus producing a baseline. When N-acetyl-L-cysteine solution is introduced into the flow injection system, it reacts with cerium(IV) increasing the analytical signal in proportion to the drug concentration. Under optimal experimental conditions, the linearity of the analytical curve for N-acetyl-L-cysteine ranged from 6.5x10 -6 to 1.3x10 -4 mol L -1 . The detection limit was 5.0x10 -6 mol L -1 and recoveries between 98.0 and 106% were obtained. The sampling frequency was 60 determinations per hour and the RSD was smaller than 1.4% for 2.2x10 -5 mol L -1 N-acetyl-L-cysteine. (author)
Cumulative Distributions and Flow Structure of Two-Passage Shear Coaxial Injector with Various Gas Injection Ratio

Energy Technology Data Exchange (ETDEWEB)

Lee, Inchul; Kim, Dohun; Koo, Jaye [Korea Aerospace Univ., Goyang (Korea, Republic of)

2013-07-15

To verify the effect of inner- and outer-stage gas jets, a shear coaxial injector was designed to analyze the axial velocity profile and breakup phenomenon with an increase in the measurement distance. When the measurement position was increased to Z/d=100, the axial flow showed a fully developed shape due to the momentum transfer, aerodynamic drag effect, and viscous mixing. An inner gas injection, which induces a higher momentum flux ratio near the nozzle, produces the greater shear force on atomization than an outer gas injection. Inner- and Outer-stage gas injection do not affect the mixing between the inner and outer gas flow below Z/d=5. The experiment results showed that the main effect of liquid jet breakup was governed by the gas jet of an inner stage. As the nozzle exit of the outer-stage was located far from the liquid column, shear force and turbulence breaking up of the liquid jets do not fully affect the liquid column. In the case of an inner-stage gas injection momentum flux ratio within 0.84, with the increase in the outer gas momentum flux ratio, the Smd decreases. However, at an inner-stage gas jet momentum flux ratio over 1.38, the Smd shows the similar distribution.
Effects of Injection Timing on Fluid Flow Characteristics of Partially Premixed Combustion Based on High-Speed Particle Image Velocimetry

KAUST Repository

Izadi Najafabadi, Mohammad

2017-03-28

Partially Premixed Combustion (PPC) is a promising combustion concept ,based on judicious tuning of the charge stratification, to meet the increasing demands of emission legislation and to improve fuel efficiency. Longer ignition delays of PPC in comparison with conventional diesel combustion provide better fuel/air mixture which decreases soot and NO emissions. Moreover, a proper injection timing and strategy for PPC can improve the combustion stability as a result of a higher level of fuel stratification in comparison with the Homogeneous Charge Compression Ignition (HCCI) concept. Injection timing is the major parameter with which to affect the level of fuel and combustion stratification and to control the combustion phasing and the heat release behavior. The scope of the present study is to investigate the fluid flow characteristics of PPC at different injection timings. To this end, high-speed Particle Image Velocimetry (PIV) is implemented in a light-duty optical engine to measure fluid flow characteristics, including the flow fields, mean velocity and cycle-resolved turbulence, inside the piston bowl as well as the squish region with a temporal resolution of 1 crank angle degree at 800 rpm. Two injectors, having 5 and 7 holes, were compared to see their effects on fluid flow and heat release behavior for different injection timings. Reactive and non-reactive measurements were performed to distinguish injection-driven and combustion-driven turbulence. Formation of vortices and higher turbulence levels enhance the air/fuel interaction, changing the level of fuel stratification and combustion duration. Results demonstrate clearly how turbulence level correlates with heat release behavior, and provide a quantitative dataset for validation of numerical simulations.
The effect of nozzle location on the concentration profiles in chemical addition tank

International Nuclear Information System (INIS)

Park, B. H.; Kim, E. K.; Ro, T. S.; Lee, C. H.

2001-01-01

A numerical analysis of the flow and injection characteristics is performed for the flow field created by water injected into a cylindrical tank with an initially stationary fluid. The flow is relevant to the operation of the chemical addition system in the chemical and volume control system( CVCS) of nuclear power plants. This study is performed to improve the current design which has a disk block inside tank. The numerical analysis for the flow and injection characteristics in chemical addition tank are carried out using CFD code FLUENT 5. Results show that the inlet nozzle installed in tangential direction at the uppermost region of the tank cylinder and the outlet nozzle located at the center of the tank bottom is very effective in enhancing the injection in the tank
A tangentially viewing visible TV system for the DIII-D divertor

International Nuclear Information System (INIS)

Fenstermacher, M.E.; Meyer, W.H.; Wood, R.D.; Nilson, D.G.; Ellis, R.; Brooks, N.H.

1997-01-01

A video camera system has been installed on the DIII-D tokamak for two-dimensional spatial studies of line emission in the lower divertor region. The system views the divertor tangentially at approximately the height of the X point through an outer port. At the tangency plane, the entire divertor from the inner wall to outside the DIII-D bias ring is viewed with spatial resolution of ∼1 cm. The image contains information from ∼90 deg of toroidal angle. In a recent upgrade, remotely controllable filter changers were added which have produced images from nominally identical discharges using different spectral lines. Software was developed to calculate the response function matrix of the optical system using distributed computing techniques and assuming toroidal symmetry. Standard sparse matrix algorithms are then used to invert the three-dimensional images onto a poloidal plane. Spatial resolution of the inverted images is 2 cm; higher resolution simply increases the size of the response function matrix. Initial results from a series of experiments with multiple identical discharges show that the emission from CII and CIII, which appears along the inner scrape-off layer above and below the X point during ELMing H mode, moves outward and becomes localized near the X point in radiative divertor operation induced by deuterium injection. copyright 1997 American Institute of Physics
Performance Analysis of Multi Stage Safety Injection Tank

International Nuclear Information System (INIS)

Shin, Soo Jai; Kim, Young In; Bae, Youngmin; Kang, Han-Ok; Kim, Keung Koo

2015-01-01

In general the integral reactor has such characteristics, the integral reactor requires a high flow rate of coolant safety injection at the initial stage of the accident in which the core level is relatively fast decreased, A medium flow rate of coolant safety injection at the early and middle stages of the accident in which the coolant discharge flow rate is relatively large due to a high internal pressure of the reactor vessel, and a low flow rate of coolant safety injection is required at the middle and late stages of the accident in which the coolant discharge flow rate is greatly reduced due to a decreased pressure of the reactor vessel. It is noted that a high flow rate of the integral reactor is quite smaller compared to a flow rate required in the commercial loop type reactor. However, a nitrogen pressurized safety injection tank has been typically designed to quickly inject a high flow rate of coolant when the internal pressure of the reactor vessel is rapidly decreased, and a core makeup tank has been designed to safely inject at a single mode flow rate due to a gravitational head of water subsequent to making a pressure balance between the reactor vessel and core makeup tank. As a result, in order to compensate such a disadvantage, various type systems are used in a complicated manner in a reactor according to the required characteristic of safety injection during an accident. In the present study, we have investigated numerically the performance of the multi stage safety injection tank. A parameter study has performed to understand the characteristics of the multi stage safety injection tank. The performance of the multi stage safety injection tank has been investigated numerically. When an accident occurs, the coolant in the multi stage safety injection tank is injected into a reactor vessel by a gravitational head of water subsequent to making a pressure balance between the reactor and tank. At the early stages of the accident, the high flow rate of
Performance Analysis of Multi Stage Safety Injection Tank

Energy Technology Data Exchange (ETDEWEB)

Shin, Soo Jai; Kim, Young In; Bae, Youngmin; Kang, Han-Ok; Kim, Keung Koo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

In general the integral reactor has such characteristics, the integral reactor requires a high flow rate of coolant safety injection at the initial stage of the accident in which the core level is relatively fast decreased, A medium flow rate of coolant safety injection at the early and middle stages of the accident in which the coolant discharge flow rate is relatively large due to a high internal pressure of the reactor vessel, and a low flow rate of coolant safety injection is required at the middle and late stages of the accident in which the coolant discharge flow rate is greatly reduced due to a decreased pressure of the reactor vessel. It is noted that a high flow rate of the integral reactor is quite smaller compared to a flow rate required in the commercial loop type reactor. However, a nitrogen pressurized safety injection tank has been typically designed to quickly inject a high flow rate of coolant when the internal pressure of the reactor vessel is rapidly decreased, and a core makeup tank has been designed to safely inject at a single mode flow rate due to a gravitational head of water subsequent to making a pressure balance between the reactor vessel and core makeup tank. As a result, in order to compensate such a disadvantage, various type systems are used in a complicated manner in a reactor according to the required characteristic of safety injection during an accident. In the present study, we have investigated numerically the performance of the multi stage safety injection tank. A parameter study has performed to understand the characteristics of the multi stage safety injection tank. The performance of the multi stage safety injection tank has been investigated numerically. When an accident occurs, the coolant in the multi stage safety injection tank is injected into a reactor vessel by a gravitational head of water subsequent to making a pressure balance between the reactor and tank. At the early stages of the accident, the high flow rate of
An automatic system for acidity determination based on sequential injection titration and the monosegmented flow approach.

Science.gov (United States)

Kozak, Joanna; Wójtowicz, Marzena; Gawenda, Nadzieja; Kościelniak, Paweł

2011-06-15

An automatic sequential injection system, combining monosegmented flow analysis, sequential injection analysis and sequential injection titration is proposed for acidity determination. The system enables controllable sample dilution and generation of standards of required concentration in a monosegmented sequential injection manner, sequential injection titration of the prepared solutions, data collecting, and handling. It has been tested on spectrophotometric determination of acetic, citric and phosphoric acids with sodium hydroxide used as a titrant and phenolphthalein or thymolphthalein (in the case of phosphoric acid determination) as indicators. Accuracy better than |4.4|% (RE) and repeatability better than 2.9% (RSD) have been obtained. It has been applied to the determination of total acidity in vinegars and various soft drinks. The system provides low sample (less than 0.3 mL) consumption. On average, analysis of a sample takes several minutes. Copyright © 2011 Elsevier B.V. All rights reserved.

Mass spectrometric confirmation criterion for product-ion spectra generated in flow-injection analysis. Environmental application

NARCIS (Netherlands)

Geerdink, R.B.; Niessen, W.M.A.; Brinkman, U.A.T.

2001-01-01

The suitability of a confirmation criterion recently recommended in the Netherlands for gas chromatography with mass spectrometric detection (GC-MS), was evaluated for flow-injection analysis (FIA) with atmospheric pressure chemical ionisation MS-MS detection. The main feature of the criterion is
Flow injection on-line preconcentration of low levels of Cr(VI) with detection by ETAAS

DEFF Research Database (Denmark)

Som-aum, Waraporn; Liawruangrath, Saisunee; Hansen, Elo Harald

2002-01-01

A flow injection (FI) on-line sorption preconcentration procedure utilizing a packed column reactor and combined with electrothermal atomic absorption spectrometry (ETAAS) is proposed for the determination of low levels of Cr(VI) in water samples. Polytetrafluoroethylene (PTFE) beads packed in a ...
Determination of uranium (IV) in cloride solutions of enrichment columns by spectrometry with flow injection

International Nuclear Information System (INIS)

Bastos, M.B.R.

1988-01-01

The utilization of Flow Injection Analysis for the U (IV) spectrophotometric determination in chloride solutions is described. The method has been shown reproducible in the range of concentrations and conditions employed with a standard deviation of about 0,3. (C.G.C.) [pt
Cardiac Dose From Tangential Breast Cancer Radiotherapy in the Year 2006

International Nuclear Information System (INIS)

Taylor, Carolyn W.; Povall, Julie M.; McGale, Paul; Nisbet, Andrew; Dodwell, David; Smith, Jonathan T.; Darby, Sarah C.

2008-01-01

Purpose: To quantify the radiation doses received by the heart and coronary arteries from contemporary tangential breast or chest wall radiotherapy. Methods and Materials: Fifty consecutive patients with left-sided breast cancer and 5 consecutive patients with right-sided breast cancer treated at a large United Kingdom radiotherapy center during the year 2006 were selected. All patients were irradiated with 6- or 8-MV tangential beams to the breast or chest wall. For each dose plan, dose-volume histograms for the heart and left anterior descending (LAD) coronary artery were calculated. For 5 of the left-sided and all 5 right-sided patients, dose-volume histograms for the right and circumflex coronary arteries were also calculated. Detailed spatial assessment of dose to the LAD coronary artery was performed for 3 left-sided patients. Results: For the 50 patients given left-sided irradiation, the average mean (SD) dose was 2.3 (0.7) Gy to the heart and 7.6 (4.5) Gy to the LAD coronary artery, with the distal LAD receiving the highest doses. The right and circumflex coronary arteries received approximately 2 Gy mean dose. Part of the heart received >20 Gy in 22 left-sided patients (44%). For the 5 patients given right-sided irradiation, average mean doses to all cardiac structures were in the range 1.2 to 2 Gy. Conclusions: Heart dose from left-tangential radiotherapy has decreased considerably over the past 40 years, but part of the heart still receives >20 Gy for approximately half of left-sided patients. Cardiac dose for right-sided patients was generally from scattered irradiation alone
Meninges control tangential migration of hem-derived Cajal-Retzius cells via CXCL12/CXCR4 signaling.

Science.gov (United States)

Borrell, Víctor; Marín, Oscar

2006-10-01

Cajal-Retzius cells are critical in the development of the cerebral cortex, but little is known about the mechanisms controlling their development. Three focal sources of Cajal-Retzius cells have been identified in mice-the cortical hem, the ventral pallium and the septum-from where they migrate tangentially to populate the cortical surface. Using a variety of tissue culture assays and in vivo manipulations, we demonstrate that the tangential migration of cortical hem-derived Cajal-Retzius cells is controlled by the meninges. We show that the meningeal membranes are a necessary and sufficient substrate for the tangential migration of Cajal-Retzius cells. We also show that the chemokine CXCL12 secreted by the meninges enhances the dispersion of Cajal-Retzius cells along the cortical surface, while retaining them within the marginal zone in a CXCR4-dependent manner. Thus, the meningeal membranes are fundamental in the development of Cajal-Retzius cells and, hence, in the normal development of the cerebral cortex.
Effects of Injection Timing on Fluid Flow Characteristics of Partially Premixed Combustion Based on High-Speed Particle Image Velocimetry

KAUST Repository

Izadi Najafabadi, Mohammad; Tanov, Slavey; Wang, Hua; Somers, Bart; Johansson, Bengt; Dam, Nico

2017-01-01

behavior. The scope of the present study is to investigate the fluid flow characteristics of PPC at different injection timings. To this end, high-speed Particle Image Velocimetry (PIV) is implemented in a light-duty optical engine to measure fluid flow
Polyion selective polymeric membrane-based pulstrode as a detector in flow-injection analysis.

Science.gov (United States)

Bell-Vlasov, Andrea K; Zajda, Joanna; Eldourghamy, Ayman; Malinowska, Elzbieta; Meyerhoff, Mark E

2014-04-15

A method for the detection of polyions using fully reversible polyion selective polymeric membrane type pulstrodes as detectors in a flow-injection analysis (FIA) system is examined. The detection electrode consists of a plasticized polymeric membrane doped with 10 wt % of tridodecylmethylammonium-dinonylnaphthalene sulfonate (TDMA/DNNS) ion-exchanger salt. The pulse sequence used involves a short (1 s) galvanostatic pulse, an open-circuit pulse (0.5 s) during which the EMF of the cell is measured, and a longer (15 s) potentiostatic pulse to return the membrane to its original chemical composition. It is shown that total pulse sequence times can be optimized to yield reproducible real-time detection of injected samples of protamine and heparin at up to 20 samples/h. Further, it is shown that the same membrane detector can be employed for FIA detection of both polycations at levels ≥10 μg/mL and polyanions at levels of ≥40 μg/mL by changing the direction of the galvanostatic pulse. The methodology described may also be applicable in the detection of polyionic species at low levels in other flowing configurations, such as in liquid chromatography and capillary electrophoresis.
Mirror System for Collecting Thomson-Scattered Light in a Tangential Direction

NARCIS (Netherlands)

Barth, C. J.; Grobben, B. J. J.; Verhaag, G. C. H. M.

1994-01-01

We describe an optical system for collecting Thomson-scattering light in the tangential direction of a tokamak. The key part of the optics is a set of mirrors arranged as a Venetian blind. This system makes it possible to look around the corner of the tokamak vessel. Design considerations and test
Improved upper bounds on energy dissipation rates in plane Couette flow with boundary injection and suction

Science.gov (United States)

Lee, Harry; Wen, Baole; Doering, Charles

2017-11-01

The rate of viscous energy dissipation ɛ in incompressible Newtonian planar Couette flow (a horizontal shear layer) imposed with uniform boundary injection and suction is studied numerically. Specifically, fluid is steadily injected through the top plate with a constant rate at a constant angle of injection, and the same amount of fluid is sucked out vertically through the bottom plate at the same rate. This set-up leads to two control parameters, namely the angle of injection, θ, and the Reynolds number of the horizontal shear flow, Re . We numerically implement the `background field' variational problem formulated by Constantin and Doering with a one-dimensional unidirectional background field ϕ(z) , where z aligns with the distance between the plates. Computation is carried out at various levels of Re with θ = 0 , 0 .1° ,1° and 2°, respectively. The computed upper bounds on ɛ scale like Re0 as Re > 20 , 000 for each fixed θ, this agrees with Kolmogorov's hypothesis on isotropic turbulence. The outcome provides new upper bounds to ɛ among any solution to the underlying Navier-Stokes equations, and they are sharper than the analytical bounds presented in Doering et al. (2000). This research was partially supported by the NSF Award DMS-1515161, and the University of Michigan's Rackham Graduate Student Research Grant.
Flow-injection fluorimetric determination of menadione using on-line photo-reduction in micellar media

Energy Technology Data Exchange (ETDEWEB)

Perez-Ruiz, Tomas; Martinez-Lozano, Carmen; Tomas, Virginia; Martin, Jesus

2004-07-01

A very sensitive fluorimetric method for the determination of menadione using a flow injection system is proposed. The method is based on the on-line reduction of menadione in dodecylsulphate micelles upon irradiation with UV light. The strong fluorescence of the reduced menadione in micellar medium is measured at 410 nm with excitation at 340 nm. The method shows a linear range between 2.42 and 245 ng ml{sup -1} and a limit of detection of 0.18 ng ml{sup -1}. The sample throughput was 90 injections per hour. The applicability of the assay was demonstrated by analysing this vitamin in commercial pharmaceutical preparations.
Flow-injection fluorimetric determination of menadione using on-line photo-reduction in micellar media

International Nuclear Information System (INIS)

Perez-Ruiz, Tomas; Martinez-Lozano, Carmen; Tomas, Virginia; Martin, Jesus

2004-01-01

A very sensitive fluorimetric method for the determination of menadione using a flow injection system is proposed. The method is based on the on-line reduction of menadione in dodecylsulphate micelles upon irradiation with UV light. The strong fluorescence of the reduced menadione in micellar medium is measured at 410 nm with excitation at 340 nm. The method shows a linear range between 2.42 and 245 ng ml -1 and a limit of detection of 0.18 ng ml -1 . The sample throughput was 90 injections per hour. The applicability of the assay was demonstrated by analysing this vitamin in commercial pharmaceutical preparations
Channel flow induced by wall injection of fluid and particles; Ecoulement induit par injection parietale de fluide et de particules dans un conduit

Energy Technology Data Exchange (ETDEWEB)

Feraille, Th.; Casalis, G. [Aerodynamics and Energetics Modeling Dept., 31 - Toulouse (France)

2003-12-01

The Taylor flow is the laminar single phase flow induced by gas injection through porous walls, and is assumed to represent the flow inside solid propellant motors. Such a flow is intrinsically unstable, and the generated instabilities are probably responsible for the thrust oscillations observed in the aforesaid motors. However particles are embedded in the propellants usually used, and are released in the fluid by the lateral walls during the combustion, so that there are two heterogeneous phases in the flow. The purpose of this paper is to study the influence of these particles on stability by comparison with stability results from the single phase studies, in a plane two-dimensional configuration. The particles are supposed to be chemically inert and of a uniform size. In order to carry out a linear stability study for this flow modified by the presence of particles, the mean particle velocity field is first determined, assuming that only the gas exerts forces on the particles. This field is sought in a self similar form, which imposes a limit on the size of the particles. However, the particle mass concentration cannot be obtained in a self similar form, but can only, be described by a partial differential equation. The mean flow characteristics being determined, the spectrum of the discretized linear stability operator shows first that particle addition does not trigger any new 'dangerous' modes compared with the single phase flow case. It also shows that the most amplified mode in the case of the single phase flow remains the most amplified mode in the case of the two phase flow. Moreover, the addition of particles acts continuously upon stability results, behaving linearly with respect to the particle mass concentration when the latter is small. The linear correction to the monophasic mode, as well as the evolution of the modes with weak values of the particle mass concentration at the wall, are shown to be proportional to the ejection velocity of
Determination of gallic acid with rhodanine by reverse flow injection analysis using simplex optimization.

Science.gov (United States)

Phakthong, Wilaiwan; Liawruangrath, Boonsom; Liawruangrath, Saisunee

2014-12-01

A reversed flow injection (rFI) system was designed and constructed for gallic acid determination. Gallic acid was determined based on the formation of chromogen between gallic acid and rhodanine, resulting in a colored product with a λmax at 520 nm. The optimum conditions for determining gallic acid were also investigated. Optimizations of the experimental conditions were carried out based on the so-call univariate method. The conditions obtained were 0.6% (w/v) rhodanine, 70% (v/v) ethanol, 0.9 mol L(-1) NaOH, 2.0 mL min(-1) flow rate, 75 μL injection loop and 600 cm mixing tubing length, respectively. Comparative optimizations of the experimental conditions were also carried out by multivariate or simplex optimization method. The conditions obtained were 1.2% (w/v) rhodanine, 70% (v/v) ethanol, 1.2 mol L(-1) NaOH, flow rate 2.5 mL min(-1), 75 μL injection loop and 600 cm mixing tubing length, respectively. It was found that the optimum conditions obtained by the former optimization method were mostly similar to those obtained by the latter method. The linear relationship between peak height and the concentration of gallic acid was obtained over the range of 0.1-35.0 mg L(-1) with the detection limit 0.081 mg L(-1). The relative standard deviations were found to be in the ranges 0.46-1.96% for 1, 10, 30 mg L(-1) of gallic acid (n=11). The method has the advantages of simplicity extremely high selectivity and high precision. The proposed method was successfully applied to the determination of gallic acid in longan samples without interferent effects from other common phenolic compounds that might be present in the longan samples collected in northern Thailand. Copyright © 2014 Elsevier B.V. All rights reserved.
Effects of GC temperature and carrier gas flow rate on on-line oxygen isotope measurement as studied by on-column CO injection.

Science.gov (United States)

Chen, Zhi-Gang; Yin, Xi-Jie; Zhou, Youping

2015-08-01

Although deemed important to δ 18 O measurement by on-line high-temperature conversion techniques, how the GC conditions affect δ 18 O measurement is rarely examined adequately. We therefore directly injected different volumes of CO or CO-N 2 mix onto the GC column by a six-port valve and examined the CO yield, CO peak shape, CO-N 2 separation, and δ 18 O value under different GC temperatures and carrier gas flow rates. The results show the CO peak area decreases when the carrier gas flow rate increases. The GC temperature has no effect on peak area. The peak width increases with the increase of CO injection volume but decreases with the increase of GC temperature and carrier gas flow rate. The peak intensity increases with the increase of GC temperature and CO injection volume but decreases with the increase of carrier gas flow rate. The peak separation time between N 2 and CO decreases with an increase of GC temperature and carrier gas flow rate. δ 18 O value decreases with the increase of CO injection volume (when half m/z 28 intensity is rate. On average, the δ 18 O value of the injected CO is about 1‰ higher than that of identical reference CO. The δ 18 O distribution pattern of the injected CO is probably a combined result of ion source nonlinearity and preferential loss of C 16 O or oxygen isotopic exchange between zeolite and CO. For practical application, a lower carrier gas flow rate is therefore recommended as it has the combined advantages of higher CO yield, better N 2 -CO separation, lower He consumption, and insignificant effect on δ 18 O value, while a higher-than-60 °C GC temperature and a larger-than-100 µl CO volume is also recommended. When no N 2 peak is expected, a higher GC temperature is recommended, and vice versa. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
Heat and mass transfer in the stratified flow with ECCS injection

International Nuclear Information System (INIS)

Strubelj, L.; Tiselj, I.

2007-01-01

One of the most important problems in the light-water nuclear thermal-hydraulics is behaviour of the cold emergency core cooling water injected from the top or from the bottom into the horizontal section of the cold leg near the reactor vessel during the loss of coolant accident. The stratified flows appear where cold water is injected in partially or fully uncovered horizontal cold leg. The hot steam condenses on cold water surface what is also called direct contact condensation. Direct contact condensation and condensation induced water-hammer in a horizontal pipe were experimentally investigated at PMK-2 test facility of the Hungarian Atomic Energy Research Institute KFKI. The cold water is injected through small pipe into lower horizontal part of the section, and then water fills the vertical pipeline and floods the horizontal test section of the pipeline of the PMK-2 integral test facility. As liquid water floods the horizontal part of the pipeline, the counter current horizontally stratified flow is being observed. During the flooding of the pipeline, the steam-liquid interface area increases and therefore the steam condensation rate and the steam velocity also increase and can lead to bubble entrapment. Water level at one cross-section and four local void fraction and temperature at the top of horizontal test pipeline was measured and compared with simulation. Condensed steam increases the water temperature that is why the local temperature measurements are the most important information, from which condensation rate can be estimated, since mass of condensed steam was not measured. Numerical simulation of the experiment with thermal phase change is presented. Surface renewal concept with small eddies is used for calculation of condensation heat transfer coefficient. Two simulations were performed: simulation of whole experimental domain (lower horizontal, vertical and test horizontal pipeline) and simplified simulation of only upper horizontal test section
Comparison of Descemet stripping under continuous air flow, manual air injection and balanced salt solution for DMEK: a pilot study.

Science.gov (United States)

Gabbay, I E; Bahar, I; Nahum, Y; Livny, E

2017-08-01

Descemet's membrane endothelial keratoplasty (DMEK) involves removal of the recipient's Descemet membrane (DM) prior to transplanting the donor's DM. When using balanced salt solution (BSS) or ophthalmic viscosurgical devices (OVDs), visualization of the host's DM during its stripping may be inadequate and may result in Descemet remnants and could lead to sub-optimal surgical results. Previous articles described excellent visualization when utilizing air injection but this requires repeated air injection into the anterior chamber (AC). We present a pilot study that compares different techniques under which DM stripping can be performed: with continuous automated air infusion, with manual air infusion, and with BSS. We retrospectively compared video footage of DM stripping with BSS, with continuous air and with manual injection of air into the AC to determine DM stripping duration and the number of times the surgeon had to insert and retrieve a surgical instrument from the AC. Thirty videos of 10 consecutive cases of the three DM stripping techniques were evaluated. DM stripping duration was 3.26 (±1.32), 3.92 (±1.2) and 12.9 (±3.98) minutes for BSS, continuous air flow, and manual air injection, respectively. Frequency of instrument retrieval (FIR) was 3.6 (±1.71), 1.5 (±0.71) and 15.1 (±3.28) for BSS, continuous air flow, and manual air injection, respectively. Continuous air flow and BSS were both statistically different than manual air injection into the AC (p air in the AC contributes to better visualization and an efficient surgery.
Spectrophotometric determination of uranium and thorium with arsenazo III in the flow injection system

International Nuclear Information System (INIS)

Andrade, M. das G.M. de.

1986-12-01

A simple system for flow injection analysis (FIA) with double confluence was built using a filter photocolorimeter, an analogic potentiometer, 'plexiglass' flow cuvettes, polyethylene colls and tubes, 'plexiglass' commuter and peristaltic pump to introduce solutions and gravity as flow source. The system was dimensioned and studied using only Arsenazo III solutions. Spectrophotometric methods for uranium and thorium using Arsenazo III were studied using a scanning spectrophotometer and after chosing adequate red filter, adapted to photocolorimetry using flow cuvettes and FIA. Synthetic samples, phosphate rock, and process samples from uranium recovery of dolomites were analysed. Rocks of Morro do Ferro (MG, Brazil), Caldasite (Baddeleyte + Zirconite), Zirconite, Monazite from a program for certification and certified rocks (Dunite DC-1, CANMET) were analysed without chemical separation of Th (IV) and with ion exchange separation in semi-micro columns of cation exchange resin (Dowex 50). (Author) [pt
Reagent-free determination of amikacin content in amikacin sulfate injections by FTIR derivative spectroscopy in a continuous flow system

Directory of Open Access Journals (Sweden)

JosÃ© F. Ovalles

2014-04-01

Full Text Available The quantitative estimation of amikacin (AMK in AMK sulfate injection samples is reported using FTIR-derivative spectrometric method in a continuous flow system. Fourier transform of mid-IR spectra were recorded without any sample pretreatment. A good linear calibration (r>0.999, %RSD<2.0 in the range of 7.7â77.0Â mg/mL was found. The results showed a good correlation with the manufacturer's and overall they all fell within acceptable limits of most pharmacopoeial monographs on AMK sulfate. Keywords: Amikacin, FTIR derivative spectrometry, Continuous flow system, Pharmaceutical preparation, Injection, Sulfate
A novel stopped flow injection-amperometric procedure for the determination of chlorate.

Science.gov (United States)

Tue-Ngeun, Orawan; Jakmunee, Jaroon; Grudpan, Kate

2005-12-15

A novel stopped flow injection-amperometric (sFI-Amp) procedure for determination of chlorate has been developed. The reaction of chlorate with excess potassium iodide and hydrochloric acid, forming iodine/triiodide that is further electrochemically reduced at a glassy carbon electrode at +200mV versus Ag/AgCl electrode is employed. In order to increase sensitivity without using of too high acid concentration, promoting of the reaction by increasing reaction time and temperature can be carried out. This can be done without increase of dispersion of the product zone by stopping the flow while the injected zone is being in a mixing coil which is immersed in a water bath of 55+/-0.5 degrees C. In a closed system of FIA, a side reaction of oxygen with iodide is also minimized. Under a set of conditions, linear calibration graphs were in the ranges of 1.2x10(-6)-6.0x10(-5)moll(-1)and 6.0x10(-5)-6.0x10(-4)moll(-1). A sample throughput of 25h(-1) was accomplished. Relative standard deviation was 2% (n=21, 1.2x10(-4)moll(-1) chlorate). The proposed sFI-Amp procedure was successfully applied to the determination of chlorate in soil samples from longan plantation area.
Automated Planning of Tangential Breast Intensity-Modulated Radiotherapy Using Heuristic Optimization

International Nuclear Information System (INIS)

Purdie, Thomas G.; Dinniwell, Robert E.; Letourneau, Daniel; Hill, Christine; Sharpe, Michael B.

2011-01-01

Purpose: To present an automated technique for two-field tangential breast intensity-modulated radiotherapy (IMRT) treatment planning. Method and Materials: A total of 158 planned patients with Stage 0, I, and II breast cancer treated using whole-breast IMRT were retrospectively replanned using automated treatment planning tools. The tools developed are integrated into the existing clinical treatment planning system (Pinnacle 3 ) and are designed to perform the manual volume delineation, beam placement, and IMRT treatment planning steps carried out by the treatment planning radiation therapist. The automated algorithm, using only the radio-opaque markers placed at CT simulation as inputs, optimizes the tangential beam parameters to geometrically minimize the amount of lung and heart treated while covering the whole-breast volume. The IMRT parameters are optimized according to the automatically delineated whole-breast volume. Results: The mean time to generate a complete treatment plan was 6 min, 50 s ± 1 min 12 s. For the automated plans, 157 of 158 plans (99%) were deemed clinically acceptable, and 138 of 158 plans (87%) were deemed clinically improved or equal to the corresponding clinical plan when reviewed in a randomized, double-blinded study by one experienced breast radiation oncologist. In addition, overall the automated plans were dosimetrically equivalent to the clinical plans when scored for target coverage and lung and heart doses. Conclusion: We have developed robust and efficient automated tools for fully inversed planned tangential breast IMRT planning that can be readily integrated into clinical practice. The tools produce clinically acceptable plans using only the common anatomic landmarks from the CT simulation process as an input. We anticipate the tools will improve patient access to high-quality IMRT treatment by simplifying the planning process and will reduce the effort and cost of incorporating more advanced planning into clinical practice.

Numerical Simulation of Magnetic Nanoparticles Injection into Two–phase Flow in a Porous Medium

KAUST Repository

El-Amin, Mohamed

2017-06-09

In this paper, the problem of magnetic nanoparticles injection into a water–oil two–phase flow under an external permanent magnetic field is investigated. The mathematical model of the problem under consideration has been developed. We treat the water-nanoparticles suspension as a miscible mixture while it is immiscible with the oil phase. The magnetized phase pressure includes an additional pressure term with the conventional thermodynamic pressure. The countercurrent imbibition flow problem is taken as an example. Physical variables including water–nanoparticles suspension saturation, nanoparticles concentration, and pore wall/throat deposited nanoparticles are investigated under the influence of the magnetic field.
Tandem collimators for the JET tangential gamma-ray spectrometer

International Nuclear Information System (INIS)

Soare, Sorin; Balshaw, Nick; Blanchard, Patrick; Craciunescu, Teddy; Croft, David; Curuia, Marian; Edlington, Trevor; Kiptily, Vasily; Murari, Andrea; Prior, Phil; Sanders, Steven; Syme, Brian; Zoita, Vasile

2011-01-01

The tangential gamma-ray spectrometer (TGRS) of the JET tokamak fusion facility is an important diagnostics for investigating the fast particle evolution. A well defined field of view for the TGRS diagnostics is essential for its proper operation and this is to be determined by a rather complex system of collimators and shields both for the neutron and gamma radiations. A conceptual design for this system has been carried out with the main design target set to maximize the signal-to-background ratio at the spectrometer detector, the ratio being defined in terms of the plasma emitted gamma radiation and the gamma-ray background. As a first phase of the TGRS diagnostics upgrade a set of two tandem collimators has been designed with the aim of determining a quasi-tangential field of view through JET tokamak plasmas. A modular design of the tandem system has been developed in order to allow for the construction of different configurations for deuterium and deuterium-tritium discharges. The internal structure of the collimators consists of nuclear grade lead and high density polyethylene slabs arranged in an optimized pattern. The performance of a simplified geometry of the tandem collimator configuration has been evaluated by neutron and photon transport calculations and the numerical results show that the design parameters can be attained.
Spiral Galaxy Central Bulge Tangential Speed of Revolution Curves

Science.gov (United States)

Taff, Laurence

2013-03-01

The objective was to, for the first time in a century, scientifically analyze the ``rotation curves'' (sic) of the central bulges of scores of spiral galaxies. I commenced with a methodological, rational, geometrical, arithmetic, and statistical examination--none of them carried through before--of the radial velocity data. The requirement for such a thorough treatment is the paucity of data typically available for the central bulge: fewer than 10 observations and frequently only five. The most must be made of these. A consequence of this logical handling is the discovery of a unique model for the central bulge volume mass density resting on the positive slope, linear, rise of its tangential speed of revolution curve and hence--for the first time--a reliable mass estimate. The deduction comes from a known physics-based, mathematically valid, derivation (not assertion). It rests on the full (not partial) equations of motion plus Poisson's equation. Following that is a prediction for the gravitational potential energy and thence the gravitational force. From this comes a forecast for the tangential speed of revolution curve. It was analyzed in a fashion identical to that of the data thereby closing the circle and demonstrating internal self-consistency. This is a hallmark of a scientific method-informed approach to an experimental problem. Multiple plots of the relevant quantities and measures of goodness of fit will be shown. Astronomy related
Effect of gas field production and CO2 injection on brine flow and salt precipitation

NARCIS (Netherlands)

Loeve, D.; Tambach, T.J.; Hofstee, C.; Plug, W.J.; Maas, J.

2012-01-01

This paper reports modeling of gas field produc-tion and CO2 injection from a theoretical reser-voir based on characteristics of the P18 gas field in the Dutch offshore, which consists of four geological deposits with different petrophysical properties. We especially focus on the brine flow during
Reverse radiometric flow injection analysis (RFIA) of radioactive waste-waters with an ASIA (Ismatec) analyzer

Energy Technology Data Exchange (ETDEWEB)

Myint, U; Win, N; San, K; Han, B; Myoe, K M [Yangon Univ. (Myanmar). Dept. of Chemistry; Toelgyessy, J [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Environmental Science

1994-07-01

A new application of reverse radiometric flow injection analysis is described. RFIA was used for the analysis of radioactive wastewaters. ASIA (Ismatec) analyzer with NaI(Tl) scintillation detector was used in the study of analysis of [sup 131]I containing waste-aster. (author) 4 refs.; 3 figs.
Meningeal defects alter the tangential migration of cortical interneurons in Foxc1hith/hith mice

Directory of Open Access Journals (Sweden)

Zarbalis Konstantinos

2012-01-01

Full Text Available Abstract Background Tangential migration presents the primary mode of migration of cortical interneurons translocating into the cerebral cortex from subpallial domains. This migration takes place in multiple streams with the most superficial one located in the cortical marginal zone. While a number of forebrain-expressed molecules regulating this process have emerged, it remains unclear to what extent structures outside the brain, like the forebrain meninges, are involved. Results We studied a unique Foxc1 hypomorph mouse model (Foxc1hith/hith with meningeal defects and impaired tangential migration of cortical interneurons. We identified a territorial correlation between meningeal defects and disruption of interneuron migration along the adjacent marginal zone in these animals, suggesting that impaired meningeal integrity might be the primary cause for the observed migration defects. Moreover, we postulate that the meningeal factor regulating tangential migration that is affected in homozygote mutants is the chemokine Cxcl12. In addition, by using chromatin immunoprecipitation analysis, we provide evidence that the Cxcl12 gene is a direct transcriptional target of Foxc1 in the meninges. Further, we observe migration defects of a lesser degree in Cajal-Retzius cells migrating within the cortical marginal zone, indicating a less important role for Cxcl12 in their migration. Finally, the developmental migration defects observed in Foxc1hith/hith mutants do not lead to obvious differences in interneuron distribution in the adult if compared to control animals. Conclusions Our results suggest a critical role for the forebrain meninges to promote during development the tangential migration of cortical interneurons along the cortical marginal zone and Cxcl12 as the factor responsible for this property.
[Determination of mercury in Boletus impolitus by flow injection-atomic absorption spectrometry].

Science.gov (United States)

Li, Tao; Wang, Yuan-Zhong

2008-04-01

Various test conditions and effect factors for the determination of mercury by flow injection-atomic absorption spectrometry were discussed, and a method for the determination of mercury in Boletus impolitus has been developed. The linear range for mercury is 0-60 microg x L(-1). The relative standard deviation is less than 3.0%, and the recovery is 96%-107%. This method is simple, rapid and has been applied to the determination of mercury in Boletus impolitus samples with satisfactory results.
Spectrophotometric determination of phosphorus in iron alloys employing a flow injection system

OpenAIRE

Gervasio,Ana P. G.; Miranda,Carlos E. S.; Luca,Gilmara C.; Tumang,Cristiane A.; Campos,Luis F. P.; Reis,Boaventura F.

2001-01-01

A flow-injection procedure for spectrophotometric determination of phosphorus in electrolytic iron and iron alloys is proposed. The method is based on the ammonium molybdate reaction followed by stannous chloride reduction in acidic medium. In order to circumvent the severe interference caused by the major constituents such as Fe(III) and Cr(III), a mini-column packed with AG50W-X8 resin was coupled to the manifold. A sample throughput of 40 determinations per hour, a dynamical range from P 0...
Experimental and finite element study of the effect of temperature and moisture on the tangential tensile strength and fracture behavior in timber logs

DEFF Research Database (Denmark)

Larsen, Finn; Ormarsson, Sigurdur

2014-01-01

Timber is normally dried by kiln drying, in the course of which moisture-induced stresses and fractures can occur. Cracks occur primarily in the radial direction due to tangential tensile strength (TSt) that exceeds the strength of the material. The present article reports on experiments and nume......Timber is normally dried by kiln drying, in the course of which moisture-induced stresses and fractures can occur. Cracks occur primarily in the radial direction due to tangential tensile strength (TSt) that exceeds the strength of the material. The present article reports on experiments...... and numerical simulations by finite element modeling (FEM) concerning the TSt and fracture behavior of Norway spruce under various climatic conditions. Thin log disc specimens were studied to simplify the description of the moisture flow in the samples. The specimens designed for TS were acclimatized...... to a moisture content (MC) of 18% before TSt tests at 20°C, 60°C, and 90°C were carried out. The maximum stress results of the disc simulations by FEM were compared with the experimental strength results at the same temperature levels. There is a rather good agreement between the results of modeling...
Dynamics and Instabilities of Free Surface and Vortex Flows

DEFF Research Database (Denmark)

Tophøj, Laust Emil Hjerrild

2012-01-01

This PhD thesis consists of two main parts. The first part describes the dynamics of an ideal fluid on a stationary free surface of a given shape. It turns out that one can formulate a set of self-contained equations of momentum conservation for the tangential flow, with no reference to the flow ......)]. Finally, an experimental work on elastic collisions of wet spheres is briefly discussed....
Transmicrocatheter local injection of ethanol to treat hepatocellular carcinoma with high flow arteriovenous shunts

International Nuclear Information System (INIS)

Guan Shouhai; Shan Hong; Jiang Zaibo; Huang Mingsheng; Zhu Kangshun; Li Zhengran; Meng Xiaochun

2002-01-01

Objective: To evaluate the feasibility and clinical effect of embolization therapy in treating the high flow hepatic arteriovenous shunts in hepatocellular carcinoma (HCC) by locally injected ethanol through microcatheter. Methods: Forty-one branches of arteriovenous shunts were treated by local ethanol infusion through microcatheter in 29 patients suffered with HCC. Angiography was performed to observe the embolization effect and influence to non-targeted vessels. Result: Forty-one branches of arteriovenous shunts in 29 patients were injected with ethanol locally. Each single shunt was infused 1-6 times. The dose of ethanol was 2-3 ml per time, and the total dose of ethanol was 2-12 ml. All shunting tracts were embolized, and all non-target vessels were protected fluently. Iodine-oil deposition was well in continued TACE. Their syndromes were improved or disappeared. Conclusion: Transmicrocatheter injection of ethanol could safely and effectively treat the hepatic arteriovenous shunts and make advantages to TACE in HCC
Shielding of the contralateral breast during tangential irradiation.

Science.gov (United States)

Goffman, Thomas E; Miller, Michael; Laronga, Christine; Oliver, Shelly; Wong, Ping

2004-08-01

The purpose of this study was to investigate both optimal and practical contralateral breast shielding during tangential irradiation in young patients. A shaped sheet of variable thickness of lead was tested on a phantom with rubber breasts, and an optimized shield was created. Testing on 18 consecutive patients 50 years or younger showed shielding consistently reduced contralateral breast dose to at least half, with small additional reduction after removal of the medial wedge. For younger patients in whom radiation exposure is of considerable concern, a simple shield of 2 mm lead thickness proved practical and effective.
Neoclassical parallel flow calculation in the presence of external parallel momentum sources in Heliotron J

Energy Technology Data Exchange (ETDEWEB)

Nishioka, K.; Nakamura, Y. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Nishimura, S. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan); Lee, H. Y. [Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Kobayashi, S.; Mizuuchi, T.; Nagasaki, K.; Okada, H.; Minami, T.; Kado, S.; Yamamoto, S.; Ohshima, S.; Konoshima, S.; Sano, F. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

2016-03-15

A moment approach to calculate neoclassical transport in non-axisymmetric torus plasmas composed of multiple ion species is extended to include the external parallel momentum sources due to unbalanced tangential neutral beam injections (NBIs). The momentum sources that are included in the parallel momentum balance are calculated from the collision operators of background particles with fast ions. This method is applied for the clarification of the physical mechanism of the neoclassical parallel ion flows and the multi-ion species effect on them in Heliotron J NBI plasmas. It is found that parallel ion flow can be determined by the balance between the parallel viscosity and the external momentum source in the region where the external source is much larger than the thermodynamic force driven source in the collisional plasmas. This is because the friction between C{sup 6+} and D{sup +} prevents a large difference between C{sup 6+} and D{sup +} flow velocities in such plasmas. The C{sup 6+} flow velocities, which are measured by the charge exchange recombination spectroscopy system, are numerically evaluated with this method. It is shown that the experimentally measured C{sup 6+} impurity flow velocities do not contradict clearly with the neoclassical estimations, and the dependence of parallel flow velocities on the magnetic field ripples is consistent in both results.
Calculation method of water injection forward modeling and inversion process in oilfield water injection network

Science.gov (United States)

Liu, Long; Liu, Wei

2018-04-01

A forward modeling and inversion algorithm is adopted in order to determine the water injection plan in the oilfield water injection network. The main idea of the algorithm is shown as follows: firstly, the oilfield water injection network is inversely calculated. The pumping station demand flow is calculated. Then, forward modeling calculation is carried out for judging whether all water injection wells meet the requirements of injection allocation or not. If all water injection wells meet the requirements of injection allocation, calculation is stopped, otherwise the demand injection allocation flow rate of certain step size is reduced aiming at water injection wells which do not meet requirements, and next iterative operation is started. It is not necessary to list the algorithm into water injection network system algorithm, which can be realized easily. Iterative method is used, which is suitable for computer programming. Experimental result shows that the algorithm is fast and accurate.
Energy harvesting through gas dynamics in the free molecular flow regime between structured surfaces at different temperatures

Science.gov (United States)

Baier, Tobias; Dölger, Julia; Hardt, Steffen

2014-05-01

For a gas confined between surfaces held at different temperatures the velocity distribution shows a significant deviation from the Maxwell distribution when the mean free path of the molecules is comparable to or larger than the channel dimensions. If one of the surfaces is suitably structured, this nonequilibrium distribution can be exploited for momentum transfer in a tangential direction between the two surfaces. This opens up the possibility to extract work from the system which operates as a heat engine. Since both surfaces are held at constant temperatures, the mode of momentum transfer is different from the thermal creep flow that has gained more attention so far. This situation is studied in the limit of free-molecular flow for the case that an unstructured surface is allowed to move tangentially with respect to a structured surface. Parameter studies are conducted, and configurations with maximum thermodynamic efficiency are identified. Overall, it is shown that significant efficiencies can be obtained by tangential momentum transfer between structured surfaces.
Estimation of the quantification uncertainty from flow injection and liquid chromatography transient signals in inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Laborda, Francisco; Medrano, Jesus; Castillo, Juan R.

2004-01-01

The quality of the quantitative results obtained from transient signals in high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) and flow injection-inductively coupled plasma mass spectrometry (FI-ICPMS) was investigated under multielement conditions. Quantification methods were based on multiple-point calibration by simple and weighted linear regression, and double-point calibration (measurement of the baseline and one standard). An uncertainty model, which includes the main sources of uncertainty from FI-ICPMS and HPLC-ICPMS (signal measurement, sample flow rate and injection volume), was developed to estimate peak area uncertainties and statistical weights used in weighted linear regression. The behaviour of the ICPMS instrument was characterized in order to be considered in the model, concluding that the instrument works as a concentration detector when it is used to monitorize transient signals from flow injection or chromatographic separations. Proper quantification by the three calibration methods was achieved when compared to reference materials, although the double-point calibration allowed to obtain results of the same quality as the multiple-point calibration, shortening the calibration time. Relative expanded uncertainties ranged from 10-20% for concentrations around the LOQ to 5% for concentrations higher than 100 times the LOQ
Liquid jets injected into non-uniform crossflow

Science.gov (United States)

Tambe, Samir

An experimental study has been conducted with liquid jets injected transversely into a crossflow to study the effect of non-uniformities in the crossflow velocity distribution to the jet behavior. Two different non-uniform crossflows were created during this work, a shear-laden crossflow and a swirling crossflow. The shear-laden crossflow was generated by merging two independent, co-directional, parallel airstreams creating a shear mixing layer at the interface between them. The crossflow exhibited a quasi-linear velocity gradient across the height of the test chamber. By varying the velocities of the two airstreams, the sense and the slope of the crossflow velocity gradient could be changed. Particle Image Velocimetry (PIV) studies were conducted to characterize the crossflow. The parameter, UR, is defined as the ratio of the velocities of the two streams and governs the velocity gradient. A positive velocity gradient was observed for UR > 1 and a negative velocity gradient for UR Phase Doppler Particle Anemometry (PDPA) studies were conducted to study the penetration and atomization of 0.5 mm diameter water jets injected into this crossflow. The crossflow velocity gradient was observed to have a significant effect on jet penetration as well as the post breakup spray. For high UR (> 1), jet penetration increased and the Sauter Mean Diameter (SMD) distribution became more uniform. For low UR (Doppler Velocimetry (LDV) was used to study the crossflow velocities. The axial (Ux) and the tangential (Utheta) components of the crossflow velocity were observed to decrease with increasing radial distance away from the centerbody. The flow angle of the crossflow was smaller than the vane exit angle, with the difference increasing with the vane exit angle. Water jets were injected from a 0.5 mm diameter orifice located on a cylindrical centerbody. Multi-plane PIV measurements were conducted to study the penetration and droplet velocity distribution of the jets. The jets were
A two-fluid model for vertical flow applied to CO₂ injection wells

DEFF Research Database (Denmark)

Linga, Gaute; Lund, Halvor

2016-01-01

Flow of CO2 in wells is associated with substantial variations in thermophysical properties downhole, due to the coupled transient processes involved: complex flow patterns, density changes, phase transitions, and heat transfer to and from surroundings. Large temperature variations can lead...... the well, including tubing, packer fluid, casing, cement or drilling mud, and rock formation. This enables prediction of the temperature in the well fluid and in each layer of the well. The model is applied to sudden shut-in and blowout cases of a CO2 injection well, where we employ the highly accurate...
Study of process parameters effect on the filling phase of micro injection moulding using weld lines as flow markers

DEFF Research Database (Denmark)

Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard

2010-01-01

, the relationships between the filling pattern and the different process parameter settings have to be established. In this paper, a novel approach based on the use of weld lines as flow markers to trace the development of the flow front during the filling is proposed. The effects on the filling stage of process......Micro-injection moulding (micro-moulding) is a process which enables the mass production of polymer microproducts. In order to produce high-quality injection moulded micro-parts, a crucial aspect to be fully understood and optimised is the filling of the cavity by the molten polymer. As a result...... manufactured by micro-electrodischarge machining. A commercially available polystyrene grade polymer has been moulded using a high-speed injection moulding machine. The design of experiment technique was employed to determine the effect of the process parameters on the filling phase of the micro...
Adaptation of a load-inject valve for a flow injection chemiluminescence system enabling dual-reagent injection enhances understanding of environmental Fenton chemistry

International Nuclear Information System (INIS)

Jones, Matthew R.; Nightingale, Philp D.; Turner, Suzanne M.; Liss, Peter S.

2013-01-01

Graphical abstract: -- Highlights: •Measurement of multiple components of Fenton chemistry; Fe(II) and H 2 O 2 . •Rapid, quasi-simultaneous analysis enables calculation of environmental kinetics. •Low, nano to pico-molar detection limits with dual analyte analysis. •Able to measure complex matrix samples – organically enriched seawater. •Low cost system with appreciable sensitivity compared to single analyte analysis. -- Abstract: Environmental Fenton chemistry has been poorly constrained within the marine environment at a multi-component level. A simple, unique, reconfiguration of a flow-injection analytical system combined with luminol chemiluminescence allows quasi-simultaneously the measurement, using a single load-inject valve and a single photon multiplier tube, of reduced iron, Fe(II), and hydrogen peroxide. The system enables rapid, every 22 s, measurements with good accuracy at environmentally relevant concentrations, less than 5% relative standard deviations on both a 5 nM Fe(II) standard and a 60 nM hydrogen peroxide standard. Limits of detection were as low as 40 pM Fe(II) and 100 pM hydrogen peroxide. The system showed excellent capability by measuring from within an organic rich seawater the photochemically induced production of Fe(II) and hydrogen peroxide and their subsequent cycling and Fenton like interactions

Cerebral blood flow in the occlusive cerebrovascular disease. 133Xe intravenous injection method

Energy Technology Data Exchange (ETDEWEB)

Kuda, Hitoshi; Mukawa, Jiro; Takara, Eiichi; Kinjo, Toshihiko; Ishikawa, Yasunari

1988-04-01

From December 1985 to May 1986, cerebral blood flow (CBF) was studied in 11 patients with occlusive cerebrovascular diseases confined by angiography. 133Xe (5mci) intravenous injection method designed by Kuikka and coworkers was applied for the measurement of regional-CBF and mean-CBF, and the calculation was based on the initial slope index. They were composed of 4 patients of the middle cerebral artery occlusion, 2 of the posterior cerebral artery occlusion, 1 of the internal carotid artery occlusion, 2 of the middle cerebral artery stenosis, 1 of the internal carotid artery stenosis, and 1 of the anterior cerebral artery stenosis. The period from the vascular attack to the initial CBF study was 2-29 days(mean 9.2 days). Recovery of mean-CBF was correlated with clinical and neurological improvement, and vice versa. There was no correlation between mean-CBF and neurological severity. CBF study alone is not sufficient to evaluate neuronal conditions in the occlusive disease. Additional other means, such as CT-scan, angiography and etc. should be requested for it. Intravenous 133Xe injection technique has an advantage over intracarotid injection method; less dangerous, especially in ages and capable of simultaneous measurement of bilateral hemisphere. Considering /sup c/ross talk/sup /regional-CBF of a low density area on X-ray CT-scan was equal to the one obtained by intracarotid injection method.
Regional cerebral blod flow studied by xenon-133. Intra-arterial injection studies and inhalation studies using emission tomography

DEFF Research Database (Denmark)

Lassen, N A

1980-01-01

.) technique is insensitive both to hyperemia and ischemia yielding essentially only a mean flow value. A new rapidly moving single photon tomograph following D. Kuhl's principle is presented applicable to Xe-133. Preliminary clinical data show that this technique is able to detect ischemic areas both with Xe......A survey of the Xenon-133 techniques for measurement of regional cerebral blood flow, rCBF, in man is presented. The intra-arterial Xe-133 injection method is very sensitive for detecting even small hyperemic areas, but cannot "see" smaller ischemic areas. The Xe-133 inhalation (or i.v. inj......-133 intra-arterial injection and with Xe-133 inhalation. The practical and economic advantages of Xe-133 or Xe-127 tomography over positron tomography for rCBF are discussed....
Rationale and Application of Tangential Scanning to Industrial Inspection of Hardwood Logs

Science.gov (United States)

Nand K. Gupta; Daniel L. Schmoldt; Bruce Isaacson

1998-01-01

Industrial computed tomography (CT) inspection of hardwood logs has some unique requirements not found in other CT applications. Sawmill operations demand that large volumes of wood be scanned quickly at high spatial resolution for extended duty cycles. Current CT scanning geometries and commercial systems have both technical and economic [imitations. Tangential...
Vastus Medialis advancement: clinical results and correlation with tangential X-rays of the patellofemoral joint

International Nuclear Information System (INIS)

O'Beirne, J.; O'Connell, R.J.; White, M.

1986-01-01

Thirteen patients who had recurrent dislocation of the patella treated by vastus medialis advancement were reviewed, and tangential X-rays of the patellofemoral joint were taken at the time of review. Clinically the results were excellent or good in ten (77%). However, the X-ray appearances were similar to what would be expected in a group of patients with untreated recurrent dislocation, probably because the corrective action of the vastus medialis did not apply with the quadriceps relaxed for X-ray. We conclude that vastus medialis advancement is a successful operation for recurrent patellar dislocation but that tangential X-rays of the patellofemoral joint are not an indicator of the outcome of surgery. (author)
Instabilities and prediction of the acoustic resonance of flows with wall injection; Instabilites et prevision de l'accrochage acoustique des ecoulements avec injection parietale

Energy Technology Data Exchange (ETDEWEB)

Avalon, G. [Office National d' Etudes et de Recherches Aerospatiales (ONERA), 91 - Palaiseau (France); Casalis, G. [Office National d' Etudes et de Recherches Aerospatiales (ONERA), 91 - Palaiseau (France)

1998-07-01

Aero-acoustic coupling that occurs inside solid propellant rocket engines can lead to a longitudinal acoustic mode resonance of the combustion chamber. This phenomenon, which can have various origins, in analyzed using the Vecla test facility and the theory of linear stability of flows. Different comparisons between the hot-wire measurements performed and the theory of stability confirm the presence of intrinsic instabilities for this type of flow. The instability allows to selectively amplify a given range of frequencies which depends on the injection velocity and on the conduit height. The results obtained seem to indicate that when this frequency range does not comprise the longitudinal acoustic mode or the first harmonics, the flow becomes turbulent downstream. (J.S.)
Radial and tangential gravity rates from GRACE in areas of glacial isostatic adjustment

Science.gov (United States)

van der Wal, Wouter; Kurtenbach, Enrico; Kusche, Jürgen; Vermeersen, Bert

2011-11-01

In areas dominated by Glacial Isostatic Adjustment (GIA), the free-air gravity anomaly rate can be converted to uplift rate to good approximation by using a simple spectral relation. We provide quantitative comparisons between gravity rates derived from monthly gravity field solutions (GFZ Potsdam, CSR Texas, IGG Bonn) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission with uplift rates measured by GPS in these areas. The band-limited gravity data from the GRACE satellite mission can be brought to very good agreement with the point data from GPS by using scaling factors derived from a GIA model (the root-mean-square of differences is 0.55 mm yr-1 for a maximum uplift rate signal of 10 mm yr-1). The root-mean-square of the differences between GRACE derived uplift rates and GPS derived uplift rates decreases with increasing GRACE time period to a level below the uncertainty that is expected from GRACE observations, GPS measurements and the conversion from gravity rate to uplift rate. With the current length of time-series (more than 8 yr) applying filters and a hydrology correction to the GRACE data does not reduce the root-mean-square of differences significantly. The smallest root-mean-square was obtained with the GFZ solution in Fennoscandia and with the CSR solution in North America. With radial gravity rates in excellent agreement with GPS uplift rates, more information on the GIA process can be extracted from GRACE gravity field solutions in the form of tangential gravity rates, which are equivalent to a rate of change in the deflection of the vertical scaled by the magnitude of gravity rate vector. Tangential gravity rates derived from GRACE point towards the centre of the previously glaciated area, and are largest in a location close to the centre of the former ice sheet. Forward modelling showed that present day tangential gravity rates have maximum sensitivity between the centre and edge of the former ice sheet, while radial gravity
Flow injection spectrofluorimetric method for the determination of cadmium

International Nuclear Information System (INIS)

Bo Tang; Taixing Yue; Lili Zhang; Junsen Wu; Zhenzhen Chen

2004-01-01

A novel fluorescent reagent, o-vanillin furoylhydrazone (OVFH), was synthesized, and its infrared spectrum, elemental analysis and dissociation constant are reported. The reaction between Cd 2+ and OVFH produces an intensely fluorescent complex in ethanol-water medium of pH 10.00, and this finding has led to a simple, rapid, and sensitive flow injection (FI) spectrofluorimetric method for on-line determination of Cd 2+ . Under the optimum experimental conditions, the fluorescent complex had excitation and emission maxima at 393 and 494 nm, respectively. The linear range is from 0.025 to 8.0 μg mL -1 of Cd 2+ , the detection limit is 7.6 μg L -1 and the maximum sampling rate is 80 h -1 . The effect of interferences was studied. The method was successfully applied to the determination of cadmium in environmental samples. (author)
Do uniform tangential interfacial stresses enhance adhesion?

Science.gov (United States)

Menga, Nicola; Carbone, Giuseppe; Dini, Daniele

2018-03-01

We present theoretical arguments, based on linear elasticity and thermodynamics, to show that interfacial tangential stresses in sliding adhesive soft contacts may lead to a significant increase of the effective energy of adhesion. A sizable expansion of the contact area is predicted in conditions corresponding to such scenario. These results are easily explained and are valid under the assumptions that: (i) sliding at the interface does not lead to any loss of adhesive interaction and (ii) spatial fluctuations of frictional stresses can be considered negligible. Our results are seemingly supported by existing experiments, and show that frictional stresses may lead to an increase of the effective energy of adhesion depending on which conditions are established at the interface of contacting bodies in the presence of adhesive forces.
One-shot flow injection spectrophotometric simultaneous determination of copper, iron and zinc in patients' sera with newly developed multi-compartment flow cell

International Nuclear Information System (INIS)

Teshima, Norio; Gotoh, Shingo; Ida, Kazunori; Sakai, Tadao

2006-01-01

We propose here an affordable flow injection method for simultaneous spectrophotometric determination of copper, iron and zinc in patients' sera. The use of a newly designed multi-compartment flow cell allowed the simultaneous determination of the three metals with a single injection ('one-shot') and a double beam spectrophotometer. The chemistry relied on the reactions of these metals with 2-(5-nitro-2-pyridylazo)-5-[N-propyl-N-(3-sulfopropyl)amino]phenol (nitro-PAPS) to form corresponding colored complexes. At pH 3.8, only copper-nitro-PAPS complex was formed in the presence of pyrophosphate as a masking agent for iron, and then the copper and iron(II) complexes were formed in the presence of reductant (ascorbic acid) at the same pH, and finally all three metals reacted with nitro-PAPS at pH 8.6. The characteristics were introduced into the flow system to determine each metal selectively and sensitively. Under the optimum conditions, linear calibration curves for the three metals were obtained in the range of 0.01-1 mg L -1 with a sample throughput rate of 20 h -1 . The limits of detection (3σ) were 3.9 μg L -1 for copper, 4.1 μg L -1 for iron and 4.0 μg L -1 for zinc. The proposed method was applied to analysis of some patients' sera
Study on effect of mixing mechanism by the transverse gaseous injection flow in scramjet engine with variable parameters

Science.gov (United States)

Yadav, Siddhita; Pandey, K. M.

2018-04-01

In scramjet engine the mixing mechanism of fuel and atmospheric air is very complicated, because the fuel have time in milliseconds for mixing with atmospheric air in combustion chamber having supersonic speed. Mixing efficiency of fuel and atmospheric air depends on mainly these parameters: Aspect ratio of injector, vibration amplitude, shock type, number of injector, jet to transverse flow momentum flux ratio, injector geometry, injection angle, molecular weight, incoming air stream angle, jet to transverse flow pressure ratio, spacing variation, mass flow rate of fuel etc. here is a very brief study of these parameters from previously done research on these parameters for the improvement of mixing efficiency. The mixing process have the significant role for the working of engine, and mixing between the atmospheric air and the jet fuel is significant factor for improving the overall thrust of the engine. The results obtained by study of papers are obtained by the 3D-Reynolds Average-Nervier-Stokes(RANS) equations along with the 2-equation k-ω shear-stress-transport (SST) turbulence model. Engine having multi air jets have 60% more mixing efficiency than single air jet, thus if the jets are increased, the mixing efficiency of engine can also be increased up to 150% by changing jet from 1 to 16. When using delta shape of injector the mixing efficiency is inversely proportional to the pressure ratio. When the fuel is injected inside the combustor from the top and bottom walls of the engine efficiency of mixing in reacting zone is higher than the single wall injection and in comparison to parallel flow, the transverse type flow is better as the atmospheric air jet can penetrate smoothly in the fuel jets and mixes well in less time. Hence this study of parameters and their effects on mixing can enhance the efficiency of mixing in engine.
Simulation study on vertically distributed multi-channel tangential interferometry for KSTAR

International Nuclear Information System (INIS)

Nam, Y U; Juhn, J W

2012-01-01

Interferometry is powerful and reliable diagnostics which measures line-integrated electron density. Since this technique only measures an averaged value over whole probing line, a multi-channel scheme is used for an analysis for spatial distribution and variation of electron density. Typical setups of the multi-channel measurement are schemes of radially distributed vertical lines, vertically distributed horizontal lines and horizontally distributed tangential lines. In Korea Superconducting Tokamak Advanced Research, a vertically distributed multi-channel tangential interferometry is planned instead of above typical schemes due to limitation of complex in-vessel geometry and narrow diagnostics port through cryostat. Total 5-channels will be vertically placed as symmetric with the mid-plain. One of the characteristic features of the vertically distributed channels is that each channel is viewing different poloidal angle, while the horizontally distributed channels are viewing different toroidal angle. This scheme also can be used on an investigation of the up-down asymmetry and the vertical oscillation of plasma. Simulation has been performed and the result will be discussed to verify the possibility and the estimated effectiveness of the scheme on this paper.
A study on the effects of the intake port configurations on the swirl flow generated in a small D.I. diesel engine

Science.gov (United States)

Kim, Yungjin; Han, Yongtaek; Lee, Kihyung

2014-06-01

This paper investigates the effect of intake port configuration on the swirl that is generated within a direct injection (D.I.) diesel engine. The in-cylinder flow characteristics are known to have significant effects on fuel-air mixing, combustion, and emissions. To clarify how to intensify the swirl flow, a swirl control valve (SCV) and a bypass were selected as design parameters for enhancing the swirl flow. The optimal intake port shape was also chosen as a parameter needed to efficiently generate a high swirl ratio. The results revealed that a key factor in generating a high swirl ratio was to control the intake airflow direction passing through the intake valve seat. Further, the swirl intensity was influenced by changing the distance between the helical and tangential ports, and the swirl flow was changed by the presence of a bypass near the intake valve seat. Additionally, the effect of intake port geometry on the in-cylinder flow field was investigated by using a laser sheet visualization method. The experimental results showed a correlation of swirl ratio and mass flow rate. In addition, we found that employing the bypass was an effective method to increase swirl ratio without sacrificing mass flow rate.
Steady State Stokes Flow Interpolation for Fluid Control

DEFF Research Database (Denmark)

Bhatacharya, Haimasree; Nielsen, Michael Bang; Bridson, Robert

2012-01-01

— suffer from a common problem. They fail to capture the rotational components of the velocity field, although extrapolation in the normal direction does consider the tangential component. We address this problem by casting the interpolation as a steady state Stokes flow. This type of flow captures......Fluid control methods often require surface velocities interpolated throughout the interior of a shape to use the velocity as a feedback force or as a boundary condition. Prior methods for interpolation in computer graphics — velocity extrapolation in the normal direction and potential flow...
Validation and Application of Computed Radiography (CR) Tangential Technique for Wall Thickness Measurement of 10 Inch Carbon Steel Pipe

International Nuclear Information System (INIS)

Norhazleena Azaman; Khairul Anuar Mohd Salleh; Amry Amin Abas; Arshad Yassin; Sukhri Ahmad

2016-01-01

Oil and gas industry requires Non Destructive Testing (NDT) to ensure each components, in-service and critical, are fit-for-purpose. Pipes that are used to transfer oil or gas are amongst the critical component that needs to be well maintained and inspected. Typical pipe discontinuities that may lead to unintended incidents are erosion, corrosion, dent, welding defects, etc. Wall thickness assessment, with Radiography Testing (RT) is normally used to inspect such discontinuities and can be performed with two approaches; (a) center line beam tangential technique (b) offset from the centre pipe tangential technique. The latter is a method of choice for this work because of the pipe dimension and limited radiation safe distance at site. Two successful validation approaches (simulation and experimental) were performed to determine the probability of successfulness before the actual RT work with tangential technique is carried out. The pipe was a 10 inch diameter in-service wrapped carbon steel. A 9 Ci Ir-192 and white Imaging Plate (IP) were used as a gamma radiation source and to record the radiographic image. Result of this work suggest that RT with tangential technique for 10 inch wrapped in-service carbon steel pipe can be successfully performed. (author)
Investigation of the noise effect on tomographic reconstructions for a tangentially viewing vacuum ultraviolet imaging diagnostic

International Nuclear Information System (INIS)

Ming, Tingfeng; Ohdachi, Satoshi; Suzuki, Yasuhiro

2011-01-01

Tomographic reconstruction for a tangentially viewing two-dimensional (2D) imaging system is studied. A method to calculate the geometry matrix in 2D tomography is introduced. An algorithm based on a Phillips-Tikhonov (P-T) type regularization method is investigated, and numerical tests using the P-T method are conducted with both tokamak and Heliotron configurations. The numerical tests show that the P-T method is not sensitive to the added noise levels and the emission profiles with higher mode numbers can be reconstructed with adequate resolution. The results indicate that this method is suitable for 2D tomographic reconstruction for a tangentially viewing vacuum ultraviolet telescope system. (author)
Impact of setup variability on incidental lung irradiation during tangential breast treatment

International Nuclear Information System (INIS)

Carter, Dennis L.; Marks, Lawrence B.; Bentel, Gunilla C.

1997-01-01

Purpose: This study aimed to determine the variability in treatment setup during a 5-week course of tangential breast treatment for patients immobilized in a customized hemibody cradle, to assess the relationship between the height of the lung shadow on the tangential port film and the percentage of lung volume irradiated, and to estimate the impact of setup variabilities on irradiated lung volume. Methods: One hundred seventy-two port films were reviewed from 20 patients who received tangential beam treatment for breast cancer. The height of the lung shadow at the central axis (CLD) on each port film was compared to the corresponding simulator film as an assessment of setup variability. A three-dimensional dose calculation was performed, and the percentage of total lung volume within the field was correlated with the CLD. The three-dimensional dose calculation was repeated for selected patients with the location of the treatment beams modified to reflect typical setup variations. Results: The CLD measured on the port films was within 3 mm of that prescribed on the simulator film in 43% (74 of 172) of the port films. The variation was 3-5 mm in 26%, 5-10 mm in 25%, and >10 mm in 6%. The height of the lung shadow correlated with the percentage of lung volume included in the radiation field (r 2 = 0.6). Typical variations in treatment setup resulted in ≤5% fluctuation in the absolute volume of ipsilateral lung irradiated. Conclusion: The current immobilization system used in our clinic provides a clinically acceptable reproducibility of patient setup. The height of the lung shadow is reasonably well correlated with the percentage of irradiated lung volume. During a typical 5-week course of radiotherapy, the ipsilateral irradiated lung volume fluctuates <5%
Geological Factors Affecting Flow Spatial Continuity in Water Injection of Units Operating in the LGITJ–0102 Ore Body

Directory of Open Access Journals (Sweden)

Ilver M. Soto-Loaiza

2016-05-01

Full Text Available The objective of the investigation was to identify the geological factors affecting the spatial continuity of the flow during the process of flank water injection in the units operating in the Lower Lagunilla Hydrocarbon Ore Body. This included the evaluation of the recovery factor, the petro-physic properties such as porosity, permeability, water saturation and rock type and quality in each flow unit. it was observed that the rock type of the geologic structure in the ore body is variable. The lowest values for the petro-physic properties were found in the southern area while a high variability of these parameters was observed in the northern and central areas. It was concluded that the northern area has a great potential for the development of new injection projects for petroleum recovery.
Rapid Quantitation of Ascorbic and Folic Acids in SRM 3280 Multivitamin/Multielement Tablets using Flow-Injection Tandem Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Bhandari, Deepak [ORNL; Kertesz, Vilmos [ORNL; Van Berkel, Gary J [ORNL

2013-01-01

RATIONALE: Ascorbic acid (AA) and folic acid (FA) are water-soluble vitamins and are usually fortified in food and dietary supplements. For the safety of human health, proper intake of these vitamins is recommended. Improvement in the analysis time required for the quantitative determination of these vitamins in food and nutritional formulations is desired. METHODS: A simple and fast (~5 min) in-tube sample preparation was performed, independently for FA and AA, by mixing extraction solvent with a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Quantitative detection was achieved by flow-injection (1 L injection volume) electrospray ionization tandem mass spectrometry (ESI-MS/MS) in negative ion mode using the method of standard addition. RESULTS: Method of standard addition was employed for the quantitative estimation of each vitamin in a sample extract. At least 2 spiked and 1 non-spiked sample extract were injected in triplicate for each quantitative analysis. Given an injection-to-injection interval of approximately 2 min, about 18 min was required to complete the quantitative estimation of each vitamin. The concentration values obtained for the respective vitamins in the standard reference material (SRM) 3280 using this approach were within the statistical range of the certified values provided in the NIST Certificate of Analysis. The estimated limit of detections of FA and AA were 13 and 5.9 ng/g, respectively. CONCLUSIONS: Flow-injection ESI-MS/MS was successfully applied for the rapid quantitation of FA and AA in SRM 3280 multivitamin/multielement tablets.
Contralateral breast doses measured by film dosimetry: tangential techniques and an optimized IMRT technique

International Nuclear Information System (INIS)

Saur, S; Frengen, J; Fjellsboe, L M B; Lindmo, T

2009-01-01

The contralateral breast (CLB) doses for three tangential techniques were characterized by using a female thorax phantom and GafChromic EBT film. Dose calculations by the pencil beam and collapsed cone algorithms were included for comparison. The film dosimetry reveals a highly inhomogeneous dose distribution within the CLB, and skin doses due to the medial fields that are several times higher than the interior dose. These phenomena are not correctly reproduced by the calculation algorithms. All tangential techniques were found to give a mean CLB dose of approximately 0.5 Gy. All wedged fields resulted in higher CLB doses than the corresponding open fields, and the lateral open fields resulted in higher CLB doses than the medial open fields. More than a twofold increase in the mean CLB dose from the medial open field was observed for a 90 deg. change of the collimator orientation. Replacing the physical wedge with a virtual wedge reduced the mean dose to the CLB by 35% and 16% for the medial and lateral fields, respectively. Lead shielding reduced the skin dose for a tangential technique by approximately 50%, but the mean CLB dose was only reduced by approximately 11%. Finally, a technique based on open medial fields in combination with several IMRT fields is proposed as a technique for minimizing the CLB dose. With and without lead shielding, the mean CLB dose using this technique was found to be 0.20 and 0.27 Gy, respectively.
Flow injection analysis simulations and diffusion coefficient determination by stochastic and deterministic optimization methods.

Science.gov (United States)

Kucza, Witold

2013-07-25

Stochastic and deterministic simulations of dispersion in cylindrical channels on the Poiseuille flow have been presented. The random walk (stochastic) and the uniform dispersion (deterministic) models have been used for computations of flow injection analysis responses. These methods coupled with the genetic algorithm and the Levenberg-Marquardt optimization methods, respectively, have been applied for determination of diffusion coefficients. The diffusion coefficients of fluorescein sodium, potassium hexacyanoferrate and potassium dichromate have been determined by means of the presented methods and FIA responses that are available in literature. The best-fit results agree with each other and with experimental data thus validating both presented approaches. Copyright © 2013 The Author. Published by Elsevier B.V. All rights reserved.

Three-dimensional numerical simulation for plastic injection-compression molding

Science.gov (United States)

Zhang, Yun; Yu, Wenjie; Liang, Junjie; Lang, Jianlin; Li, Dequn

2018-03-01

Compared with conventional injection molding, injection-compression molding can mold optical parts with higher precision and lower flow residual stress. However, the melt flow process in a closed cavity becomes more complex because of the moving cavity boundary during compression and the nonlinear problems caused by non-Newtonian polymer melt. In this study, a 3D simulation method was developed for injection-compression molding. In this method, arbitrary Lagrangian- Eulerian was introduced to model the moving-boundary flow problem in the compression stage. The non-Newtonian characteristics and compressibility of the polymer melt were considered. The melt flow and pressure distribution in the cavity were investigated by using the proposed simulation method and compared with those of injection molding. Results reveal that the fountain flow effect becomes significant when the cavity thickness increases during compression. The back flow also plays an important role in the flow pattern and redistribution of cavity pressure. The discrepancy in pressures at different points along the flow path is complicated rather than monotonically decreased in injection molding.
Impact of physical properties of biodiesel on the injection process in a common-rail direct injection system

International Nuclear Information System (INIS)

Boudy, Frederic; Seers, Patrice

2009-01-01

This paper presents the influence of biodiesel fuel properties on the injection mass flow rate of a diesel common-rail injection system. Simulations are first performed with ISO 4113 diesel fuel on a four-cylinder common-rail system to evaluate a single and triple injection strategies. For each injection strategy, the impact of modifying a single fuel property at a time is evaluated so as to quantify its influence on the injection process. The results show that fuel density is the main property that affects the injection process, such as total mass injected and pressure wave in the common-rail system. The fuel's viscosity and bulk modulus also influence, but to a lessen degree, the mass flow rate of the injector notably during multiple injection strategies as individual properties change the fuel's dampening property and friction coefficient.
Flow injection spectrophotometric determination of low concentrations of orthosphate in natural waters employing ion exchange resin

International Nuclear Information System (INIS)

Pessenda, L.C.R.

1981-01-01

A simple and fast method for the determination of low concentrations of orthophosphate in natural waters is described. Ion exchange is incorporated into a flow injection system by usina a resin column in the sample loop of a proportion injector. Effects of sample aspiration rate, sampling time, eluting agent concentration, pumping rate of the sample carrier stream and interfaces, were investigated both using 32 PO 3- 4 or 31 PO 3- 4 with columns coupled to a gerger-muller detector and incorporated in a flow system with molybdenum blue colorinetry. (M.A.C.) [pt
Physical modelling of near-wall phenomena in entrained-flow coal gasifiers

OpenAIRE

Troiano, Maurizio

2015-01-01

Combustion and gasification under slagging conditions are key aspects of the design of modern entrained-flow reactors for thermal conversion of solid fuels, aimed at increasing the overall energy efficiency. In these systems, solid particles migrate toward the reactor walls, due to swirled/tangential flow induced in the reaction chamber and to turbophoresis, generating, thanks to the very high operating temperatures, a slag layer that flows along the reactor internal walls and is drained to t...
Effect of cross-flow direction of coolant on film cooling effectiveness with one inlet and double outlet hole injection

Directory of Open Access Journals (Sweden)

Guangchao Li

2012-12-01

Full Text Available In order to study the effect of cross-flow directions of an internal coolant on film cooling performance, the discharge coefficients and film cooling effectiveness with one inlet and double outlet hole injections were simulated. The numerical results show that two different cross-flow directions of the coolant cause the same decrease in the discharge coefficients as that in the case of supplying coolant by a plenum. The different proportion of the mass flow out of the two outlets of the film hole results in different values of the film cooling effectiveness for three different cases of coolant supplies. The film cooling effectiveness is the highest for the case of supplying coolant by the plenum. At a lower blowing ratio of 1.0, the film cooling effectiveness with coolant injection from the right entrance of the passage is higher than that from the left entrance of the passage. At a higher blowing ratio of 2.0, the opposite result is found.
A novel automatic flow method with direct-injection photometric detector for determination of dissolved reactive phosphorus in wastewater and freshwater samples.

Science.gov (United States)

Koronkiewicz, Stanislawa; Trifescu, Mihaela; Smoczynski, Lech; Ratnaweera, Harsha; Kalinowski, Slawomir

2018-02-12

The novel automatic flow system, direct-injection detector (DID) integrated with multi-pumping flow system (MPFS), dedicated for the photometric determination of orthophosphates in wastewater and freshwater samples is for the first time described. All reagents and the sample were injected simultaneously, in counter-current into the reaction-detection chamber by the system of specially selected for this purpose solenoid micro-pumps. The micro-pumps provided good precision and accuracy of the injected volumes. For the determination of orthophosphates, the molybdenum blue method was employed. The developed method can be used to detect orthophosphate in the range 0.1-12 mg L -1 , with the repeatability (RSD) about 2.2% at 4 mg L -1 and a very high injection throughput of 120 injections h -1 . It was possible to achieve a very small consumption of reagents (10 μL of ammonium molybdate and 10 μL of ascorbic acid) and sample (20 μL). The volume of generated waste was only 440 μL per analysis. The method has been successfully applied, giving a good accuracy, to determination of orthophosphates in complex matrix samples: treated wastewater, lake water and reference sample of groundwater. The developed system is compact, small in both size and weight, requires 12 V in supply voltage, which are desirable for truly portable equipment used in routine analysis. The simplicity of the system should result in its greater long-time reliability comparing to other flow methods previously described.
Preliminary three-dimensional potential flow simulation of a five-liter flask air injection experiment

International Nuclear Information System (INIS)

Davis, J.E.

1977-01-01

The preliminary results of an unsteady three-dimensional potential flow analysis of a five-liter flask air injection experiment (small-scale model simulation of a nuclear reactor steam condensation system) are presented. The location and velocity of the free water surface in the flask as a function of time are determined during pipe venting and bubble expansion processes. The analyses were performed using an extended version of the NASA-Ames Three-Dimensional Potential Flow Analysis System (POTFAN), which uses the vortex lattice singularity method of potential flow analysis. The pressure boundary condition at the free water surface and the boundary condition along the free jet boundary near the pipe exit were ignored for the purposes of the present study. The results of the analysis indicate that large time steps can be taken without significantly reducing the accuracy of the solutions and that the assumption of inviscid flow should not have an appreciable effect on the geometry and velocity of the free water surface. In addition, the computation time required for the solutions was well within acceptable limits
Continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process: An efficient diesel treatment by injection of the aqueous phase.

Science.gov (United States)

Rahimi, Masoud; Shahhosseini, Shahrokh; Movahedirad, Salman

2017-11-01

A new continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process was developed in order to decrease energy and aqueous phase consumption. In this process the aqueous phase is injected below the horn tip leading to enhanced mixing of the phases. Diesel fuel as the oil phase with sulfur content of 1550ppmw and an appropriate mixture of hydrogen peroxide and formic acid as the aqueous phase were used. At the first step, the optimized condition for the sulfur removal has been obtained in the batch mode operation. Hence, the effect of more important oxidation parameters; oxidant-to-sulfur molar ratio, acid-to-sulfur molar ratio and sonication time were investigated. Then the optimized conditions were obtained using Response Surface Methodology (RSM) technique. Afterwards, some experiments corresponding to the best batch condition and also with objective of minimizing the residence time and aqueous phase to fuel volume ratio have been conducted in a newly designed double-compartment reactor with injection of the aqueous phase to evaluate the process in a continuous flow operation. In addition, the effect of nozzle diameter has been examined. Significant improvement on the sulfur removal was observed specially in lower sonication time in the case of dispersion method in comparison with the conventional contact between two phases. Ultimately, the flow pattern induced by ultrasonic device, and also injection of the aqueous phase were analyzed quantitatively and qualitatively by capturing the sequential images. Copyright © 2017 Elsevier B.V. All rights reserved.
Asymmetry of radial and symmetry of tangential neuronal migration pathways in developing human fetal brains

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Yuta eMiyazaki

2016-01-01

Full Text Available AbstractThe radial and tangential neural migration pathways are two major neuronal migration streams in humans that are critical during corticogenesis. Corticogenesis is a complex process of neuronal proliferation that is followed by neuronal migration and the formation of axonal connections. Existing histological assessments of these two neuronal migration pathways have limitations inherent to microscopic studies and are confined to small anatomic regions of interest. Thus, little evidence is available about their three-dimensional fiber pathways and development throughout the entire brain. In this study, we imaged and analyzed radial and tangential migration pathways in the whole human brain using high-angular resolution diffusion MR imaging (HARDI tractography. We imaged ten fixed, postmortem fetal (17 gestational weeks (GW, 18 GW, 19 GW, three 20 GW, three 21 GW and 22 GW and eight in vivo newborn (two 30 GW, 34 GW, 35 GW and four 40 GW brains with no neurological/pathological conditions. We statistically compared the volume of the left and right radial and tangential migration pathways, and the volume of the radial migration pathways of the anterior and posterior regions of the brain. In specimens 22 GW or younger, the volume of radial migration pathways of the left hemisphere was significantly larger than that of the right hemisphere. The volume of posterior radial migration pathways was also larger when compared to the anterior pathways in specimens 22 GW or younger. In contrast, no significant differences were observed in the radial migration pathways of brains older than 22 GW. Moreover, our study did not identify any significant differences in volumetric laterality in the tangential migration pathways. These results suggest that these two neuronal migration pathways develop and regress differently, and radial neuronal migration varies regionally based on hemispheric and anterior-posterior laterality, potentially explaining regional
Bienzymatic Biosensor for Rapid Detection of Aspartame by Flow Injection Analysis

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Maria-Cristina Radulescu

2014-01-01

Full Text Available A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX, carboxyl esterase (CaE and bovine serum albumin (BSA were immobilised with glutaraldehyde (GA onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC. The biosensor response was fast. The sample throughput using a flow injection analysis (FIA system was 40 h−1 with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 µM for methanol and 0.2 µM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples without any pre-treatment step prior to measurement.
Bienzymatic biosensor for rapid detection of aspartame by flow injection analysis.

Science.gov (United States)

Radulescu, Maria-Cristina; Bucur, Bogdan; Bucur, Madalina-Petruta; Radu, Gabriel Lucian

2014-01-09

A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h⁻¹ with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 µM for methanol and 0.2 µM for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement.
The mathematical model structural-parametric synthesis of working processes in an oxygen-methane steam generator with flow swirl

Science.gov (United States)

Timoshinova, T. S.; Shmatov, D. P.; Kretinin, A. V.; Drozdov, I. G.

2017-11-01

While formulating a mathematical model of the flow and interaction between oxygen-methane fuel combustion products with tangentially swirled ballast water injected in the end of the combustion chamber in CAE product Fluent, which integrated into the ANSYS Workbench platform, the problem of structural-parametric synthesis is solved for structure optimization of the model. Equations are selected from the catalogue of Fluent physical models. Also optimization helps to find “regime” model parameters that determine the specific implementation of the model inside the synthesized structure. As a result, such solutions which were developed during creation of a numerical algorithm, as the choice of a turbulence model and the state equation, the methods for determining the thermodynamic thermophysical characteristics of combustion products, the choice of the radiation model, the choice of the resistance law for drops, the choice of the expression which allows to evaluate swirling flows lateral force, determination of the turbulent dispersion strength, choice of the mass exchange law, etc. Fields of temperature, pressure, velocity and volume fraction of phases were obtained at different ballast water mass flows. Dependence of wall temperature from mass flow of ballast water is constructed, that allows us to compare results of the experiment and mathematical modeling.
Clinical studies on the lymph flow of the esophagus by injecting sup(99m)Tc-rhenium colloid into the esophageal wall

International Nuclear Information System (INIS)

Baba, Masamichi; Tanabe, Gen; Nishi, Mitsumasa

1985-01-01

Using 29 operative cases lymph flow of the esophagus was investigated by injecting endoscopically sup(99m)Tc-Rhenium colloid. Rhenium colloid lymphoscintigraphy was made, and 30 -- 32 hours after injection RI up take (cpm/g) of resected lymph nodes was counted by scintillation counter. 1. RI up take of resected lymph nodes correspond with the lymphoscintigraphy of resected lymph nodes therefore, RI up take count was available to study the extra-mural lymph flow of the esophagus. 2. In the cases injected at upper part of the esophagus, the high counted RI up take was noted in bifurcation lymph nodes, upper mediastinal lymph nodes and bilateral supraclavicular lymph nodes. In the cases injected at middle part of the esophagus, bilateral supraclavicular lymph nodes, upper mediastinal lymph nodes and left gastric artery lymph nodes revealed the high RI up takes. In the cases injected at lower part of the esophagus, RI up take was highly noted in bifurcation lymph nodes, left gastric artery lymph nodes and celiac axis lymph nodes. In the cases injected at esophago-gastric junction, the high counted RI up take was noted in left gastric artery lymph nodes, celiac axis lymph nodes and the lymph nodes around the left renal vein. 3. In the cases injected at upper, middle parts of the esophagus, bilateral supraclavicular lymph nodes revealed the high RI up take. Some of these lymph nodes are regarded as directly connected with the extra-mural lymph vessls of the esophagus. Therefore, it was suggested that existence of ''direct lymph flow'' from which upper, middle intrathoracic esophagus directly connected to right supraclavicular lymph nodes. 4. It is important to perform bilateral modified neck dissection in case of upper, middle intrathoracic esophageal cancer and is important to dissect the lymph nodes around the left renal vein in case of esophago-gastric cancer and lower intrathoracic esophageal cancer. (J.P.N.)
Experimental Investigation of Diffuser Hub Injection to Improve Centrifugal Compressor Stability

Science.gov (United States)

Skoch, Gary J.

2004-01-01

Results from a series of experiments to investigate whether centrifugal compressor stability could be improved by injecting air through the diffuser hub surface are reported. The research was conducted in a 4:1 pressure ratio centrifugal compressor configured with a vane-island diffuser. Injector nozzles were located just upstream of the leading edge of the diffuser vanes. Nozzle orientations were set to produce injected streams angled at 8, 0 and +8 degrees relative to the vane mean camber line. Several injection flow rates were tested using both an external air supply and recirculation from the diffuser exit. Compressor flow range did not improve at any injection flow rate that was tested. Compressor flow range did improve slightly at zero injection due to the flow resistance created by injector openings on the hub surface. Leading edge loading and semi-vaneless space diffusion showed trends similar to those reported earlier from shroud surface experiments that did improve compressor flow range. Opposite trends are seen for hub injection cases where compressor flow range decreased. The hub injection data further explain the range improvement provided by shroud-side injection and suggest that different hub-side techniques may produce range improvement in centrifugal compressors.
Propellant Feed System for Swirl-Coaxial Injection

Science.gov (United States)

Reynolds, David Christopher (Inventor)

2015-01-01

A propellant feed system for swirl-coaxial injection of a liquid propellant includes a reservoir having a bottom plate and at least one tube originating in the bottom plate and extending therefrom. The tube has rectangular slits defined in and distributed tangentially and evenly about a portion of the tube that is disposed in the bottom plate. Drain holes are provided in the bottom plate and tunnels are defined in the bottom plate. Each tunnel fluidly couples one of the drain holes to a corresponding one of the rectangular slits. Each tunnel includes (i) a bend of at least 90.degree., and (ii) a straight portion leading to its corresponding rectangular slit wherein the straight portion is at least five times as long as a hydraulic diameter of the corresponding rectangular slit.
Development of high-performance and low-noise axial-flow fan units in their local operating region

Energy Technology Data Exchange (ETDEWEB)

Heo, Seung; Ha, Min Ho; Cheong, Cheol Ung [Pusan National University, Busan (Korea, Republic of); Kim, Tae Hoon [LG Electronics Inc., Changwon (Korea, Republic of)

2015-09-15

Aerodynamic and aeroacoustic performances of an axial-flow fan unit are improved by modifying its housing structure without changing the fan blade. The target axial-flow fan system is used to lower temperature of a compressor and a condenser in the machine room of a household refrigerator which has relatively high system resistance due to complex layout of structures inside it. First, the performance of the fan system is experimentally characterized by measuring its volume flow rate versus static pressure using a fan performance tester satisfying the AMCA (Air Movement and Control Association) regulation, AMCA 210-07. The detailed structure of flow driven by the fan is numerically investigated using a virtual fan performance tester based on computational fluid dynamics techniques. The prediction result reveals possible loss due to radial and tangential velocity components in the wake flow downstream of the fan. The length of the fan housing is chosen as a design parameter for improving the aerodynamic and aeroacoustic performances of the fan unit by reducing the identified radial and tangential velocity components. Three fan units with different housing lengths longer than the original are analyzed using the virtual fan performance tester. The results confirm the improved aerodynamic performance of the proposed three designs. The flow field driven by the proposed fan unit is closely examined to find the causes for the observed performance improvements, which ensures that the radial and tangential velocity components in the wake flow are reduced. Finally, the improved performance of the proposed fan systems is validated by comparing the P-Q and efficiency curves measured using the fan performance tester. The noise emission from the household refrigerator is also found to be lessened when the new fan units are installed.
Application of a field flow preconcentration system with a minicolumn packed with amberlite XAD-4/1-(2-pyridylazo)-2-naphtol and a flow injection-flame atomic adsorption spectrometric system for lead determination in sea water

International Nuclear Information System (INIS)

Carmen Yebra, M. del; Rodriguez, L.; Puig, L.; Moreno-Cid, A.

2002-01-01

A field flow preconcentration technique involving a minicolumn containing Amberlite XAD-4 impregnated with the complexing agent 1-(2-pyridylazo)-2-naphthol was used to preconcentrate lead from seawater. Elution of retained lead on the minicolumns was performed by a flow-injection-flame atomic absorption spectrometric system. Factorial designs have been used to optimize the field flow preconcentration system and the flow injection elution process. Factors such as sample pH, sample flow-rate, eluent concentration and volume (hydrochloric acid), elution flow-rate and minicolumn diameter were considered. The results suggest that the sample flow-rate and the eluent volume are statistically significant factors. The detection limit (3σ) of the procedure was 5 ng/L for a sample volume of 1000 ml. The precision (expressed as relative standard deviation) for eleven independent determinations reached values of 4.0-3.1 % in lead solutions of 50-200 ng/L. This procedure has been successfully applied to the determination of lead in seawater from Galicia (Spain). (author)
Amenability of European silver fir (Abies alba Mill.) to preservative treatment by the full-cell process in longitudinal, tangential, radial and triplex flow pathways on the base of wood drying

Energy Technology Data Exchange (ETDEWEB)

Usta, Ilker [Wood Products Industrial Engineering, Hacettepe University, 06532-Beytepe, Ankara (Turkey)

2006-08-15

This paper discusses the effects of wood drying upon treatability (as determined by preservative uptake and gain-in-weight retention) of European silver fir on the two moisture content (MC) levels which were designed to be above and below the fibre saturation point (FSP). The treatability behaviour was investigated for individual flow pathways: longitudinal (L, along the stem), tangential (T, along the growth rings) and radial (R, along the rays), and also for the triplex (t, cumulative of all three directions: all faces left open). As the FSP was observed 32.7%, MC of the experimental samples-for each flow path-nominated to around 50% and 9% by recommended kiln drying schedule using a conventional kiln. The samples were then treated with a 2.5% concentration of commercial Tanalith C of CCA (chromium/copper/arsenic) via a mild schedule of full-cell impregnation process using a model pressure treatment plant. Treatability of European silver fir was noticed in different behaviour in either flow paths before and after drying. According to the experimental results, MC regulate the preservative uptake (as the percentage of void volume filled with preservative, VVF%) along the grain (L) and VVF% was improved by kiln drying process effectively, however, it was seemed to be contradictory across the grain (in both T and R). In the cumulative form (t), treatability-in either above or below the FSP-was appeared to be slightly greater than that for L due to support of the longitudinal flow. Therefore, it could be suggested that wood material which is subjected to be used in constructional purposes has to be initially dried to below the FSP, and - for efficient preservative treatment - it has to be treated with all faces unsealed (free from any pre-coating and/or painting). This shall be more ideal which in turn influences the quality of treated wood allowing better performance in its service life. (author)
A study on the performance and internal flow characteristics of a very low specific speed centrifugal pump

International Nuclear Information System (INIS)

Choi, Young Do; Kurokawa, Junichi; Lee, Young Ho

2005-01-01

In the very low specific speed range (n s < 0.25, non-dimensional), the efficiency of centrifugal pump designed by a conventional method is very low in common. Therefore, positive-displacement pumps have long been used widely. Recently, since the centrifugal pumps are becoming higher in rotational speed and smaller in size, there experts to develop a new centrifugal pump with a high performance to replace the positive-displacement pumps. The purpose of this study is to investigate the internal flow characteristics of a very low specific speed centrifugal pump and to examine the effect of internal flow pattern on pump performance. The results show that the theoretical head definition of semi-open impeller should be revised by the consideration of high slip factor in the semi-open impeller, and the leakage flow through the tip clearance results in a large effect on the impeller internal flow. Strong reverse flow at the outlet of semi-open impeller reduces the absolute tangential velocity considerably, and the decreased absolute tangential velocity increases the slip factor with the reduction of theoretical head
Flow-injection system for automated dissolution testing of isoniazid tablets with chemiluminescence detection.

Science.gov (United States)

Li, B; Zhang, Z; Liu, W

2001-05-30

A simple and sensitive flow-injection chemiluminescence (CL) system for automated dissolution testing is described and evaluated for monitoring of dissolution profiles of isoniazid tablets. The undissolved suspended particles in the dissolved solution were eliminated via on-line filter. The novel CL system of KIO(4)-isoniazid was also investigated. The sampling frequency of the system was 120 h(-1). The dissolution profiles of isoniazid fast-release tablets from three sources were determined, which demonstrates the stability, great sensitivity, large dynamic measuring range and robustness of the system.

Effect of Process Parameters on Flow Length and Flash Formation in Injection Moulding of High Aspect Ratio Polymeric Micro Features

Directory of Open Access Journals (Sweden)

Abdelkhalik Eladl

2018-01-01

Full Text Available This paper reports an investigation of the effects of process parameters on the quality characteristics of polymeric parts produced by micro injection moulding (μIM with two different materials. Four injection moulding process parameters (injection velocity, holding pressure, melt temperature and mould temperature were investigated using Polypropylene (PP and Acrylonitrile Butadiene Styrene (ABS. Three key characteristics of the mouldings were evaluated with respect to process settings and the material employed: part mass, flow length and flash formation. The experimentation employs a test part with four micro fingers with different aspect ratios (from 21 up to 150 and was carried out according to the Design of Experiments (DOE statistical technique. The results show that holding pressure and injection velocity are the most influential parameters on part mass with a direct effect for both materials. Both parameters have a similar effect on flow length for both PP and ABS at all aspect ratios and have higher effects as the feature thickness decreased below 300 μm. The study shows that for the investigated materials the injection speed and packing pressure were the most influential parameters for increasing the amount of flash formation, with relative effects consistent for both materials. Higher melt and mould temperatures settings were less influential parameters for increasing the flash amount when moulding with both materials. Of the two investigated materials, PP was the one exhibiting more flash formation as compared with ABS, when corresponding injection moulding parameters settings for both materials were considered.
Radial lean direct injection burner

Science.gov (United States)

Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

2012-09-04

A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.
Chemiluminescence determination of ultramicro DNA with a flow-injection method

International Nuclear Information System (INIS)

Chen Hui; Zhou Min; Jin Xiaoyong; Song Yumin; Zhang Ziyu; Ma Yongjun

2002-01-01

A high sensitive flow-injection chemiluminescence method for determination of calf thymus DNA and herring sperm DNA has been developed. The method is based on the chemiluminescence reaction of Rhodamine B-cerium(IV)-thermally denatured DNAs in sulfuric acid media. The proposed procedure allows quantitation of DNAs in the range 2.6x10 -5 to 0.26 μg ml -1 for calf thymus DNA and 5.0x10 -8 to 5.0x10 -5 μg ml -1 for herring sperm DNA with correlation coefficients 0.9998 and 0.9996 (both n=11), respectively. The detection limits (3σ) are 6.5x10 -6 μg ml -1 for calf thymus DNA and 4.3x10 -8 μg ml -1 for herring sperm DNA. The possible mechanism of chemiluminescence in the system is discussed
Numerical Simulations of Two-Phase Reacting Flow in a Single-Element Lean Direct Injection (LDI) Combustor Using NCC

Science.gov (United States)

Liu, Nan-Suey; Shih, Tsan-Hsing; Wey, C. Thomas

2011-01-01

A series of numerical simulations of Jet-A spray reacting flow in a single-element lean direct injection (LDI) combustor have been conducted by using the National Combustion Code (NCC). The simulations have been carried out using the time filtered Navier-Stokes (TFNS) approach ranging from the steady Reynolds-averaged Navier-Stokes (RANS), unsteady RANS (URANS), to the dynamic flow structure simulation (DFS). The sub-grid model employed for turbulent mixing and combustion includes the well-mixed model, the linear eddy mixing (LEM) model, and the filtered mass density function (FDF/PDF) model. The starting condition of the injected liquid spray is specified via empirical droplet size correlation, and a five-species single-step global reduced mechanism is employed for fuel chemistry. All the calculations use the same grid whose resolution is of the RANS type. Comparisons of results from various models are presented.
Water injection profiling by nuclear logging

International Nuclear Information System (INIS)

Arnold, D.M.

1980-01-01

This invention relates to nuclear logging techniques for determining the volume flow rates and flow directions of injected water moving behind a wellbore casing. The apparatus includes a sonde equipped with a neutron source and dual radiation detectors. Oxygen in the neutron irradiated water is transmitted to 16 N and the resultant primary and Compton scattered gamma rays are detected in two energy windows by both detectors. Count rate data is analysed in terms of the windows to obtain linear flow velocities for water flow within and behind the casing. Volume flow rates are determined for upward and downward flow, and horizontal volume flow into the surrounding formation is calculated. A complete injection profile may thus be obtained. (U.K.)
Analytical and numerical solution of three-dimensional channel flow in presence of a sinusoidal fluid injection and a chemical reaction

Directory of Open Access Journals (Sweden)

Sahin Ahmed

2015-06-01

Full Text Available Modeling of three-dimensional channel flow in a chemically-reacting fluid between two long vertical parallel flat plates in the presence of a transverse magnetic field is presented. The stationary plate is subjected to a transverse sinusoidal injection velocity distribution while the uniformly moving plate is subjected to a constant suction and slip boundary conditions. Due to this type of injection velocity, the flow becomes three dimensional. Comparisons with previously published work are performed and the results are found to be in excellent agreement. An increase in the permeability/magnetic parameter is found to escalate the velocity near the plate in motion. Growing Reynolds number or magnetic parameter enhances the x-component and reduces the z-component of the skin-friction at the wall at rest. The acquired knowledge in our study can be used by designers to control MHD flow as suitable for certain applications which include laminar magneto-aerodynamics, materials processing and MHD propulsion thermo-fluid dynamics.
Radial and tangential friction in heavy ion strongly damped collisions

International Nuclear Information System (INIS)

Jain, A.K.; Sarma, N.

1979-01-01

Deeply inelastic heavy ion collisions have been successfully described in terms of a nucleon exchange mechanism between two nucleon clouds. This model has also predicted the large angular momentum that is induced in the colliding nuclei. However computations were simplified in the earlier work by assuming that the friction was perturbation on the elastic scattering trajectory. Results of a more rigorous calculation are reported and the effect of modification of the trajectory on the energy transfer, the angular momentum induced and on the ratio of the radial to the tangential friction coefficients is reported. (auth.)
Reduction of Altitude Diffuser Jet Noise Using Water Injection

Science.gov (United States)

Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

2011-01-01

A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.
Imaging diagnostics of ethanol port fuel injection sprays for automobile engine applications

International Nuclear Information System (INIS)

Padala, Srinivas; Le, Minh Khoi; Kook, Sanghoon; Hawkes, Evatt R.

2013-01-01

This paper presents characteristics of ethanol sprays at port fuel injection (PFI) conditions with variations in injection and ambient parameters. Details of temporal and spatial development of ethanol PFI sprays are studied using Mie-scattering and high-speed shadowgraph imaging techniques. Momentum flux-based injection rate measurement is also performed. The influences of fuel flow-rate, injection duration, and ambient air cross-flow are of particular interest in an effort to understand ethanol PFI spray characteristics that are relevant to automobile engines. For comparison purposes, the results from gasoline fuel are also presented. Ethanol flow-rate effects are studied using two injectors with different nozzle-hole sizes at a fixed injection pressure. From the experiments, it was found that the actual injection duration was longer for the higher flow-rate injector although an electronic pulse width was fixed. This was due to an extended delay in the injector needle closing as the flow resistance against the needle was increased for the high flow-rate injector. For liquid droplets, the larger hole size of the higher flow-rate injector caused a higher mean droplet diameter and higher number of droplets. Injection duration was also varied to study transient spray behaviour: short-injection sprays with the end-of-injection transient dominating the overall spray development were compared to long, steady-injection sprays. From Mie-scattering images, the number of droplets and mean droplet diameter were found to be less for the short injection sprays. Detailed analysis using an axial profile of the number of droplets and mean droplet diameter suggested that the observed trends were a result of increased evaporation rate near the nozzle after the end of injection. This was consistent with shadowgraph images showing no liquid regions but only the vapour-phase fuel near the nozzle. Under the influence of ambient air cross-flow, both mean droplet diameter and number of
Optimum design of the injection duct system of a stenter machine

Energy Technology Data Exchange (ETDEWEB)

Juraeva, Makhsuda; Song, Dong Joo [Yeungnam University, Geyongsan (Korea, Republic of); Ryu, Kyung Jin [Ajou Motor College, Boryeong (Korea, Republic of)

2017-05-15

Stenter machines are used for drying fabrics in the textile industry and have a heater, injection duct system, and fans inside a chamber. The injection duct system has ducts and air-injecting holes. Plane-type injection duct systems were investigated to obtain uniform airflow at the air-injecting holes. The flow field of the injection duct systems was computed using ANSYS CFX with different heights of the duct end and different shapes for the air-injecting holes. There was a high mass flow rate at the air-injecting holes and high airflow circulation inside both plane-type and mountain-type ducts at the ends. The height of the duct end was varied between 40 mm and 160 mm. The injection duct systems were analyzed with four different shapes of air-injecting holes. The circular and elliptical holes had lower standard deviations of the mass flow rate than other shapes. Relatively uniform mass flow rates were obtained in the plane-type and mountain-type duct systems when the height of the duct end was 40 mm and the shape of the air-injecting holes was circular or elliptical. The developed injection duct systems were improved by obtaining a uniform mass flow rate at the air-injecting holes. A stenter prototype was fabricated with the developed injection duct system to confirm the numerical results. The developed injection duct system had better performance than the original system.
New method for simultaneous determination of Fe(II) and Fe(III) in water using flow injection technique

International Nuclear Information System (INIS)

Kozak, J.; Gutowski, J.; Kozak, M.; Wieczorek, M.; Koscielniak, P.

2010-01-01

The method exploits the possibilities of flow injection gradient titration in a system of reversed flow with spectrophotometric detection. In the developed approach a small amount of titrant (EDTA) is injected into a stream of sample containing a mixture of indicators (sulfosalicylic acid and 1,10-phenanthroline). In acid environment sulfosalicylic acid forms a complex with Fe(III), whereas 1,10-phenanthroline forms a complex with Fe(II). Measurements are performed at wavelength λ = 530 nm when radiation is absorbed by both complexes. After injection EDTA replaces sulfosalicylic acid and forms with Fe(III) more stable colourless complex. As a result, a characteristic 'cut off' peak is registered with a width corresponding to the Fe(III) concentration and with a height corresponding to the Fe(II) concentration. Calibration was performed by titration of four two-component standard solutions of the Fe(II)/Fe(III) concentrations established in accordance with 2 2 factorial plan. The method was tested with the use of synthetic samples and then it was applied to the analysis of water samples taken from artesian wells. Under optimized experimental conditions Fe(II) and Fe(III) were determined with precision less than 0.8 and 2.5% (RSD) and accuracy less than 3.2 and 5.1% (relative error) within the concentration ranges of 0.1-3.0 and 0.9-3.5 mg L -1 of both analytes, respectively.
Application of a novel metabolomic approach based on atmospheric pressure photoionization mass spectrometry using flow injection analysis for the study of Alzheimer's disease.

Science.gov (United States)

González-Domínguez, Raúl; García-Barrera, Tamara; Gómez-Ariza, José Luis

2015-01-01

The use of atmospheric pressure photoionization is not widespread in metabolomics, despite its considerable potential for the simultaneous analysis of compounds with diverse polarities. This work considers the development of a novel analytical approach based on flow injection analysis and atmospheric pressure photoionization mass spectrometry for rapid metabolic screening of serum samples. Several experimental parameters were optimized, such as type of dopant, flow injection solvent, and their flows, given that a careful selection of these variables is mandatory for a comprehensive analysis of metabolites. Toluene and methanol were the most suitable dopant and flow injection solvent, respectively. Moreover, analysis in negative mode required higher solvent and dopant flows (100 µl min(-1) and 40 µl min(-1), respectively) compared to positive mode (50 µl min(-1) and 20 µl min(-1)). Then, the optimized approach was used to elucidate metabolic alterations associated with Alzheimer's disease. Thereby, results confirm the increase of diacylglycerols, ceramides, ceramide-1-phosphate and free fatty acids, indicating membrane destabilization processes, and reduction of fatty acid amides and several neurotransmitters related to impairments in neuronal transmission, among others. Therefore, it could be concluded that this metabolomic tool presents a great potential for analysis of biological samples, considering its high-throughput screening capability, fast analysis and comprehensive metabolite coverage. Copyright © 2014 Elsevier B.V. All rights reserved.
First-In-Flight Full-Scale Application of Active Flow Control: The XV-15 Tiltrotor Download Reduction

National Research Council Canada - National Science Library

Nagib, Hassan M; Kiedaisch, John W; Wygnanski, Israel J; Stalker, Aaron D; Wood, Tom; McVeigh, Michael A

2004-01-01

... the effectiveness of Active flow Control (AFC) in reducing the download during hover. The flaps/ailerons were retrofitted with actuators delivering zero-mass-flux periodic jets emanating from slots positioned tangential to the surface...
Transient performance analysis of pressurized safety injection tank with a partition

International Nuclear Information System (INIS)

Bae, Youngmin; Kim, Young In; Kim, Keung Koo

2015-01-01

Highlights: • Functional performance of safety injection tanks with a partition is evaluated. • Effects of key design parameters are scrutinized. • Distinctive features of the flow in multi-unit safety injection tanks are explored. - Abstract: A parametric study has been performed to evaluate the functional performance of a pressurized multi-unit safety injection tank, which would be considered as one of the candidates for a passive safety injection system in a nuclear power plant. The influences of key design parameters including the orifice size, initial gas fraction, and resistance coefficients and operating condition on the injection flow rate are scrutinized with a discussion of the relevant flow features such as the choked flow of gas through an orifice and two interconnected regions of differing gaseous pressure. The obtained results indicate that a multi-unit safety injection tank can passively control the injection flow rate and provide a stable safety injection over a relatively long period even in the case of drastic depressurization of a reactor coolant system
Large-scale bedforms induced by supercritical flows and wave-wave interference in the intertidal zone (Cap Ferret, France)

Science.gov (United States)

Vaucher, Romain; Pittet, Bernard; Humbert, Thomas; Ferry, Serge

2017-11-01

The Cap Ferret sand spit is situated along the wave-dominated, tidally modulated Atlantic coast of western France, characterized by a semidiurnal macrotidal range. It displays peculiar dome-like bedforms that can be observed at low tide across the intertidal zone. These bedforms exhibit a wavelength of ca. 1.2 m and an elevation of ca. 30 cm. They occur only when the incident wave heights reach 1.5-2 m. The internal stratifications are characterized by swaley-like, sub-planar, oblique-tangential, oblique-tabular, as well as hummocky-like stratifications. The tabular and tangential stratifications comprise prograding oblique sets (defined as foresets and backsets) that almost always show variations in their steepness. Downcutting into the bottomsets of the oblique-tangential stratifications is common. The sets of laminae observed in the bedforms share common characteristics with those formed by supercritical flows in flume experiments of earlier studies. These peculiar bedforms are observed at the surf-swash transition zone where the backwash flow reaches supercritical conditions. This type of flow can explain their internal architecture but not their general dome-like (three-dimensional) morphology. Wave-wave interference induced by the geomorphology (i.e. tidal channel) of the coastal environment is proposed as explanation for the localized formation of such bedforms. This study highlights that the combination of supercritical flows occurring in the surf-swash transition zone and wave-wave interferences can generate dome-like bedforms in intertidal zones.
Urinary bladder blood flow. I. Comparison of clearance of locally injected 99mtechnetium pertechnate and radioactive microsphere technique in dogs

DEFF Research Database (Denmark)

Krøyer, Kristian; Bülow, J; Nielsen, S L

1990-01-01

The blood flow of the dog urinary bladder measured by radioactive microsphere technique was compared to the clearance of locally injected 99mTechnetium pertechnate (99mTc) in the bladder wall. In semilogarithmic plots the 99mTc washout curves showed a multiexponential course. From the initial...... slopes (median 5.7 min) the bladder blood flow was calculated to be only 30-62% of the results obtained from the radioactive microsphere technique (blood flow in the muscular layer 21.7-44.8 ml/100 g/min). These lower values imply that the rate of removal of the hydrophilic tracer 99mTc at these flow...... blood flow....
A Customizable Flow Injection System for Automated, High Throughput, and Time Sensitive Ion Mobility Spectrometry and Mass Spectrometry Measurements

Energy Technology Data Exchange (ETDEWEB)

Orton, Daniel J. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Tfaily, Malak M. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Moore, Ronald J. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; LaMarche, Brian L. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Zheng, Xueyun [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Fillmore, Thomas L. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Chu, Rosalie K. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Weitz, Karl K. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Monroe, Matthew E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Kelly, Ryan T. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Smith, Richard D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Baker, Erin S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, United States

2017-12-13

To better understand disease conditions and environmental perturbations, multi-omic studies (i.e. proteomic, lipidomic, metabolomic, etc. analyses) are vastly increasing in popularity. In a multi-omic study, a single sample is typically extracted in multiple ways and numerous analyses are performed using different instruments. Thus, one sample becomes many analyses, making high throughput and reproducible evaluations a necessity. One way to address the numerous samples and varying instrumental conditions is to utilize a flow injection analysis (FIA) system for rapid sample injection. While some FIA systems have been created to address these challenges, many have limitations such as high consumable costs, low pressure capabilities, limited pressure monitoring and fixed flow rates. To address these limitations, we created an automated, customizable FIA system capable of operating at diverse flow rates (~50 nL/min to 500 µL/min) to accommodate low- and high-flow instrument sources. This system can also operate at varying analytical throughputs from 24 to 1200 samples per day to enable different MS analysis approaches. Applications ranging from native protein analyses to molecular library construction were performed using the FIA system. The results from these studies showed a highly robust platform, providing consistent performance over many days without carryover as long as washing buffers specific to each molecular analysis were utilized.
Evaluation of Flow-Injection Tandem Mass Spectrometry for Rapid and High-Throughput Quantitative Determination of B-Vitamins in Nutritional Supplements

Energy Technology Data Exchange (ETDEWEB)

Bhandari, Deepak [ORNL; Van Berkel, Gary J [ORNL

2012-01-01

The use of flow-injection electrospray ionization tandem mass spectrometry for rapid and high-throughput mass spectral analysis of selected B-vitamins, viz. B1, B2, B3, B5, and B6, in nutritional formulations was demonstrated. A simple and rapid (~5 min) in-tube sample preparation was performed by adding extraction solvent to a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Automated flow injection introduced 1 L of the extracts directly into the mass spectrometer ion source without chromatographic separation. Sample-to-sample analysis time was 60 s representing significant improvement over conventional liquid chromatography approaches which typically require 25-45 min, and often require more significant sample preparation procedures. Quantitative capabilities of the flow-injection analysis were tested using the method of standard additions and NIST standard reference material (SRM 3280) multivitamin/multielement tablets. The quantity determined for each B-vitamin in SRM 3280 was within the statistical range provided for the respective certified values. The same sample preparation and analysis approach was also applied to two different commercial vitamin supplement tablets and proved to be successful in the quantification of the selected B-vitamins as evidenced by an agreement with the labels values and the results obtained using isotope dilution liquid chromatography/mass spectrometry.
Flow Injection Analysis

DEFF Research Database (Denmark)

Hansen, Elo Harald

1998-01-01

Learning objectives:* To provide an introduction to automated assays* To describe the basic principles of FIA * To demonstrate the capabilities of FIA in relation to batch assays and conventional continuous flow systems* To show that FIA allows one to augment existing analytical techniques* To sh...... how FIA offers novel analytical procedures which are not feasible by conventional means* To hightlight the potentials of FIA in selected practical assays...
Chemiluminescent determination of vanadium(IV) using a cinchomeronic hydrazide-H2O2 system and flow injection analysis

International Nuclear Information System (INIS)

Pradana Perez, J.A.; Alegria, J.S. Durand; Hernando, P. Fernandez; Sierra, A. Narros

2005-01-01

This paper proposes a new chemiluminescent flow injection analysis (FIA) method for the determination of vanadium(IV) ions in aqueous media. The method is based on the chemiluminescent reaction that occurs between cinchomeronic hydrazide (CH) and hydrogen peroxide in a strongly alkaline medium, in which vanadium(IV) acts as a catalyst. The chemical and physical variables involved in the flow injection system are optimised using a modified simplex method. Vanadium ions can be detected in the 0.08 and 1.00 μg mL -1 range; the detection limit for a signal-to-noise ratio of 3 is 0.08 μg mL -1 . Great variations in the quantum yield were observed when cobalt(II), chromium(III), copper(II) and/or nickel(II) were present in the reaction medium. The proposed method is selective and simple, and can be successfully used to analyse water samples without the need for separation or preconcentration processes

Chemiluminescence determination of ultramicro DNA with a flow-injection method

Energy Technology Data Exchange (ETDEWEB)

Chen Hui; Zhou Min; Jin Xiaoyong; Song Yumin; Zhang Ziyu; Ma Yongjun

2002-02-12

A high sensitive flow-injection chemiluminescence method for determination of calf thymus DNA and herring sperm DNA has been developed. The method is based on the chemiluminescence reaction of Rhodamine B-cerium(IV)-thermally denatured DNAs in sulfuric acid media. The proposed procedure allows quantitation of DNAs in the range 2.6x10{sup -5} to 0.26 {mu}g ml{sup -1} for calf thymus DNA and 5.0x10{sup -8} to 5.0x10{sup -5} {mu}g ml{sup -1} for herring sperm DNA with correlation coefficients 0.9998 and 0.9996 (both n=11), respectively. The detection limits (3{sigma}) are 6.5x10{sup -6} {mu}g ml{sup -1} for calf thymus DNA and 4.3x10{sup -8} {mu}g ml{sup -1} for herring sperm DNA. The possible mechanism of chemiluminescence in the system is discussed.
Determination of tellurium in lead and lead alloy using flow injection-hydride generation atomic absorption spectrometry

International Nuclear Information System (INIS)

Mesko, Marcia F.; Pozebon, Dirce; Flores, Erico M.M.; Dressler, Valderi L.

2004-01-01

A method based on flow injection-hydride generation atomic absorption spectrometry (FI-HG AAS) for the determination of trace amount of Te in lead and lead alloy is described. A flow injection system (FI) and related analytical parameters as well as Te determination and interference caused by Pb, Bi and Ag on Te were investigated. The Pb interference could be overcome by using a small sample volume, while the Bi interference could be overcome by thiourea. However, it was not possible to minimise the interference caused by Ag on Te. The optimised conditions for Te determination in the analysed samples were: 6 mol l -1 HCl as sample carrier solution, 0.75% (m/v) sodium tetrahydroborate as Te reductant, 40 μl of sample solution, and 200 ml min -1 Ar flow rate as carrier gas. The limit of quantification (LOQ) was 1.0 μg g -1 Te (using 250 mg of sample in 50 ml final solution), the limit of detection (LOD) was 2.5 μg l -1 and the relative standard deviation (RSD) was 6% for five consecutive measurements of sample solution. The standard addition calibration method was used. Relatively high sample throughput (ca. 45 sample runs can be performed in a working hour), reduced sample manipulation since matrix separation is not necessary, and minor waste generation are the main advantages of the proposed method for Te determination by FI-HG AAS
Injection dynamics of gelled propellants

Science.gov (United States)

Yoon, Changjin

Gel propellants have been recognized as attractive candidates for future propulsion systems due to the reduced tendency to spill and the energy advantages over solid propellants. One of strong benefits emphasized in gel propellant applications is a throttling capability, but the accurate flow control is more complicated and difficult than with conventional Newtonian propellants because of the unique rheological behaviors of gels. This study is a computational effort directed to enhance understanding of the injector internal flow characteristics for gel propellants under rocket injection conditions. In simulations, the emphasized rheology is a shear-thinning which represents a viscosity decrease with increasing a shear rate. It is described by a generalized Newtonian fluid constitutive equation and Carreau-Yasuda model. Using this rheological model, two injection schemes are considered in the present study: axially-fed and cross-fed injection for single-element and multi-element impinging injectors, respectively. An axisymmetric model is developed to describe the axially-fed injector flows and fully three-dimensional model is utilized to simulate cross-fed injector flows. Under axially-fed injection conditions investigated, three distinct modes, an unsteady, steady, and hydraulic flip mode, are observed and mapped in terms of Reynolds number and orifice design. In an unsteady mode, quasi-periodic oscillations occur near the inlet lip leading mass pulsations and viscosity fluctuations at the orifice exit. This dynamic behavior is characterized using a time-averaged discharge coefficient, oscillation magnitude and frequency by a parametric study with respect to an orifice design, Reynolds number and rheology. As a result, orifice exit flows for gel propellants appear to be significantly influenced by a viscous damping and flow resistance due to a shear thinning behavior and these are observed in each factors considered. Under conditions driven by a manifold crossflow
Development of flow injection method for indirect copper determination with amperometric detection in drinking water samples

Directory of Open Access Journals (Sweden)

Nikolić-Mandić Snežana

2012-01-01

Full Text Available A gas-diffusion flow injection method with amperometric detection for indirect copper determination on a silver electrode is developed. The flow through system is equipped with two injection valves and a gas-diffusion unit. In the first step, a signal of cyanide solution was recorded. In the following step a signal of cyanide in the presence of copper was measured. Interferences (Cd(II, Co(II, Ag(I, Ni(II, Fe(III, Hg(II and Zn(II were investigated and successfully removed. The calibration graph is linear in the range 1-90 μmol dm-3 of copper, correlation coefficient is 0.993, the regression equation is I = (0.0455±0.0015c + (0.4611±0.0671, I is relative signal decrease in μA and c is concentration in μmol dm-3. Relative standard deviation for six consecutive injections of 30 μmol dm-3 copper(II was 1.47 % and for 1 μmol dm-3 copper(II was 3.40 %. The detection limit, calculated as 3 s/m (where s is a standard deviation of nine measurement of a reagent blank and m is the slope of the calibration curve, was 0.32 μmol dm-3, which corresponds to 2.44 ng of copper(II (loop volume was 0.12 cm3. The method enables 60 analyses per hour and it was successfully applied on determination of copper in drinking water samples. [Acknowledgements. The authors acknowledge the grant from the Ministry of Education and Science of the Republic of Serbia, Project number 172051
Effect of intracoronary nitroprusside injection on flow recovery during primary PCI in acute STEMI patients.

Science.gov (United States)

Yang, Lixia; Mu, Lihua; Sun, Linhui; Qi, Feng; Guo, Ruiwei

2017-04-01

The no/slow reflow phenomenon during primary percutaneous coronary intervention (PPCI) causes the destruction of the coronary microcirculation and further myocardial damage. Some studies have shown that intracoronary nitroprusside infusion is a safe and effective method for managing the no/slow reflow phenomenon. However, it is uncertain whether the injection of nitroprusside at a specific time point during PPCI can most effectively prevent no-reflow. In this study, we investigated the effect of the timing of an intracoronary nitroprusside injection on flow recovery during PPCI in patients with ST elevation acute myocardial infarction (STEMI). One hundred twenty consecutive patients with STEMI who underwent PPCI were enrolled in the study. Patients who fulfilled the eligibility criteria were randomly allocated to three groups: control group (N.=40) received no nitroprusside before they completed PCI; the second group (N.=40) received nitroprusside before balloon dilatation; and the third group (N.=40) received nitroprusside after each balloon dilatation and before contrast agent refilling. The baseline clinical variables and the details of the PCI procedure were collected. The thrombolysis in myocardial infarction (TIMI) flow grades and the corrected TIMI frame count (cTFC) were evaluated immediately after stent implantation was completed. There were no significant differences in the baseline characteristics, antithrombotic drugs given before PCI, and details of the PCI procedure among the three groups (P>0.05). The incidence of TIMI grade 3 after PCI was significantly higher in the nitroprusside group than in the control group (P=0.025), whereas cTFC was significantly lower in the nitroprusside group (26.6±15.2) than in the control group (38.1±21.3, P=0.001). The incidence of TIMI grade 3 after PCI was significantly higher in the third group than in the second group (P=0.045), and cTFC was significantly lower in the third group (21.5±9.5) than in the second
An alternative to FASTSIM for tangential solution of the wheel-rail contact

Science.gov (United States)

Sichani, Matin Sh.; Enblom, Roger; Berg, Mats

2016-06-01

In most rail vehicle dynamics simulation packages, tangential solution of the wheel-rail contact is gained by means of Kalker's FASTSIM algorithm. While 5-25% error is expected for creep force estimation, the errors of shear stress distribution, needed for wheel-rail damage analysis, may rise above 30% due to the parabolic traction bound. Therefore, a novel algorithm named FaStrip is proposed as an alternative to FASTSIM. It is based on the strip theory which extends the two-dimensional rolling contact solution to three-dimensional contacts. To form FaStrip, the original strip theory is amended to obtain accurate estimations for any contact ellipse size and it is combined by a numerical algorithm to handle spin. The comparison between the two algorithms shows that using FaStrip improves the accuracy of the estimated shear stress distribution and the creep force estimation in all studied cases. In combined lateral creepage and spin cases, for instance, the error in force estimation reduces from 18% to less than 2%. The estimation of the slip velocities in the slip zone, needed for wear analysis, is also studied. Since FaStrip is as fast as FASTSIM, it can be an alternative for tangential solution of the wheel-rail contact in simulation packages.
Stall margin improvement of an axial flow fan with end wall injection and suction; Hekimen fukidashi suidashi ni yoru han'yo jikuryu sofuki no shissoku kaizen

Energy Technology Data Exchange (ETDEWEB)

Nishioka, K.; Kuroda, H.; Obata, S.; Chimura, O. [National Defense Academy, Kanagawa (Japan)

1999-06-25

The experimental studies are conducted to reveal the mechanism of stall margin improvement of an axial flow fan by injection or suction from the end wall. In case of injection, the largest improvement is obtained by the injection at about 0. 14 {approx} 0 .21 times axial chord length downstream from leading edge. The reason for large improvement is that stall vortex, shed intermittent separation vortex and tip leakage vortex are dissipated by this injection, and also that this blowing suppresses the separation of boundary layer. In case of suction, the largest improvement is found for the suction from the end wall near leading edge. The amplitude of periodic static pressure after stall inception becomes smaller in comparison with injection cases. These effects are increased with the increase of suction flow rate, because the discharge of the vortex occurs more easily. On the other hand, the suction from the upstream of leading edge reduces the axial velocity near rotor tip, and then it induces stall. Also we tried to visualize the tip region flow, The suppression mechanism is discussed based on the visualization. The suppression of stall is successfully photographed. (author)
Comparison of Flow Injection MS, NMR, and DNA Sequencing: Methods for Identification and Authentication of Black Cohosh (Actaea racemosa)

Science.gov (United States)

Flow injection mass spectrometry (FIMS) and proton nuclear magnetic resonance spectrometry (1H-NMR), two metabolic fingerprinting methods, and DNA sequencing were used to identify and authenticate Actaea species. Initially, samples of Actaea racemosa L. from a single source were distinguished from ...
Mathematical Model of Two Phase Flow in Natural Draft Wet-Cooling Tower Including Flue Gas Injection

Directory of Open Access Journals (Sweden)

Hyhlík Tomáš

2016-01-01

Full Text Available The previously developed model of natural draft wet-cooling tower flow, heat and mass transfer is extended to be able to take into account the flow of supersaturated moist air. The two phase flow model is based on void fraction of gas phase which is included in the governing equations. Homogeneous equilibrium model, where the two phases are well mixed and have the same velocity, is used. The effect of flue gas injection is included into the developed mathematical model by using source terms in governing equations and by using momentum flux coefficient and kinetic energy flux coefficient. Heat and mass transfer in the fill zone is described by the system of ordinary differential equations, where the mass transfer is represented by measured fill Merkel number and heat transfer is calculated using prescribed Lewis factor.
Research on injection characteristics of venturi scrubber worked in self-priming mode

International Nuclear Information System (INIS)

Zhou Yanmin; Sun Zhongning; Gu Haifeng; Miao Zhuang

2015-01-01

The injection characteristics of Venturi scrubber worked in self-priming mode in containment filter venting system was studied experimentally under different air flows, liquid levels and system pressures. The results indicate that with the increase of superficial gas velocity in throat, the static pressure drop of both sides of the suction grows approximately following a parabolic law, and the injection flow rate injecting into the Venturi scrubber increases linearly. The effect of liquid level on injection characteristics relates closely with the relative position to the outlet of the Venturi scrubber. When the liquid level is below the outlet, the injection flow rate improves significantly with increasing liquid level and presents a partition phenomenon, and in the low throat velocity, the increase of liquid level is more effective to improve the injection flow rate. However, when the liquid level is above the outlet, it almost has no impact on the injection flow rate. The pressure is another important factor affecting the injection characteristic of self-priming Venturi scrubber, which is mainly caused by the change on gas density. In the range of 0.150 kPa, with the increase of pressure, the injection flow rate improves greatly and the influence of pressure is more obvious in high throat velocity than in low throat velocity. (authors)
Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

DEFF Research Database (Denmark)

Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne

1986-01-01

A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve......, programmable from the microcomputer, to control the sample volume. No pre-treatment of the samples is necessary. The limit of detection is 0.14 mg l–1, and only small amounts of serum (
Micelle-mediated methodology for the preconcentration of uranium prior to its determination by flow injection

Energy Technology Data Exchange (ETDEWEB)

Fernandez Laespada, M E; Perez Pavon, J L; Moreno Cordero, B [Univ. de Salamanca (Spain). Dept. de Quimica Analitica, Nutricion y Bromatologia

1993-02-01

Cloud point extraction has been used for the preconcentration of uranium, prior to its determination by flow injection. The non-ionic surfactant employed was Triton X-114 and the reagent chosen to form a hydrophobic chelate of uranium was 1-(2-pyridylazo)-2-naphthol. The optimum conditions for the preconcentration and determination of uranium have been studied. This methodology has been applied to the determination of trace amounts of uranium in tap and river waters from Salamanca. (Author).
On-line Speciation of Cr(III) and Cr(VI) by Flow Injection Analysis With Spectrophotometric Detection and Chemometrics

DEFF Research Database (Denmark)

Diacu, Elena; Andersen, Jens Enevold Thaulov

2003-01-01

A flow injection system has been developed, for on-line speciation. of Cr(III) and Cr(VI) by the Diphenylcarbazide (DPC) method with H2O2 oxidation followed by spectrophotometric detection at the 550 nm wavelength. The data thus obtained were subjected to a chemometric analysis (PLS), which showe...
Flow-injection analysis of nitrate by reduction to nitrite and gas-phase molecular absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Haghighi, B.; Tavassoli, A. [Dept. of Chemistry, Inst. for Advanced Studies in Basic Sciences, Zanjan (Iran)

2001-12-01

Two flow-injection manifolds have been investigated for the determination of nitrate. These manifolds are based on the reduction of nitrate to nitrite and determination of nitrite by gas-phase molecular absorption spectrophotometry. Nitrate sample solution (300 {mu}L) which is injected to the flow line, is reduced to nitrite by reaction with hydrazine or passage through the on-line copperized cadmium (Cd-Cu) reduction column. The nitrite produced reacts with a stream of hydrochloric acid and the evolved gases are purged into the stream of O{sub 2}carrier gas. The gaseous phase is separated from the liquid phase using a gas-liquid separator and then swept into a flow-through cell which has been positioned in the cell compartment of an UV-visible spectrophotometer. The absorbance of the gaseous phase is measured at 204.7 nm. A linear relationship was obtained between the intensity of absorption signals and concentration of nitrate when Cd-Cu reduction method was used, but a logarithmic relationship was obtained when the hydrazine reduction method was used. By use of the Cd-Cu reduction method, up to 330 {mu}g of nitrate was determined. The limit of detection was 2.97 {mu}g nitrate and the relative standard deviations for the determination of 12.0, 30.0 and 150 {mu}g nitrate were 3.32, 3.87 and 3.6%, respectively. Maximum sampling rate was approximately 30 samples per hour. The Cd-Cu reduction method was applied to the determination of nitrate and the simultaneous determination of nitrate and nitrite in meat products, vegetables, urine, and a water sample. (orig.)
Quasistatic Seismic Damage Indicators for RC Structures from Dissipating Energies in Tangential Subspaces

Directory of Open Access Journals (Sweden)

Wilfried B. Krätzig

2014-01-01

Full Text Available This paper applies recent research on structural damage description to earthquake-resistant design concepts. Based on the primary design aim of life safety, this work adopts the necessity of additional protection aims for property, installation, and equipment. This requires the definition of damage indicators, which are able to quantify the arising structural damage. As in present design, it applies nonlinear quasistatic (pushover concepts due to code provisions as simplified dynamic design tools. Substituting so nonlinear time-history analyses, seismic low-cycle fatigue of RC structures is approximated in similar manner. The treatment will be embedded into a finite element environment, and the tangential stiffness matrix KT in tangential subspaces then is identified as the most general entry for structural damage information. Its spectra of eigenvalues λi or natural frequencies ωi of the structure serve to derive damage indicators Di, applicable to quasistatic evaluation of seismic damage. Because det KT=0 denotes structural failure, such damage indicators range from virgin situation Di=0 to failure Di=1 and thus correspond with Fema proposals on performance-based seismic design. Finally, the developed concept is checked by reanalyses of two experimentally investigated RC frames.
Analysis of the Numerical Modelling of Turbulence in the Conical Reverse-Flow Cyclone

Directory of Open Access Journals (Sweden)

Inga Jakštonienė

2011-02-01

Full Text Available The paper describes the numerical modelling of the swirling fluid flow in the Stairmand cyclone (conical reverse-flow – CRF with tangential inlet (equipment for separating solid particles from the gaseous fluid flow. A review of experimental and theoretical papers is conducted introducing three-dimensional differential equations for transfer processes. The numerical modelling of the Stairmand cyclone the height of which is 0.75 m, diameter – 0.17 m, the height of a cylindrical part – 0.290 m, a conical part – 0,39 m and an inlet area is 0,085×0,032 m is presented. When governing three-dimensional fluid flow, transfer equations Navje-Stokes and Reynolds are solved using the finite volume method in a body-fitted co-ordinate system using standard k– e and RNG k– e model of turbulence. Modelling is realised for inlet velocity 4.64, 9.0 and 14.8 m/s (flow rate was 0.0112, 0.0245 and 0.0388 m3/s. The results obtained from the numerical tests have demonstrated that the RNG k– e model of turbulence yields a reasonably good prediction for highly swirling flows in cyclones: the presented numerical results (tangential and radial velocity profiles are compared with numerical and experimental data obtained by other authors. The mean relative error of ± 7,5% is found. Keywords: cyclone, solid particles, numerical modelling, turbulence, one-phase flow.DOI: 10.3846/mla.2010.085
Multimodal flow visualization and optimization of pneumatic blood pump for sorbent hemodialysis system.

Science.gov (United States)

Shu, Fangjun; Parks, Robert; Maholtz, John; Ash, Steven; Antaki, James F

2009-04-01

Renal Solutions Allient Sorbent Hemodialysis System utilizes a two-chambered pneumatic pump (Pulsar Blood Pump, Renal Solutions, Inc., Warrendale, PA, USA) to avoid limitations associated with peristaltic pumping systems. Single-needle access is enabled by counter-pulsing the two pump chambers, thereby obviating compliance chambers or blood reservoirs. Each chamber propels 20 cc per pulse of 3 s (dual access) or 6 s (single access) duration, corresponding to a peak Reynolds number of approximately 8000 (based on inlet velocity and chamber diameter). A multimodal series of flow visualization studies (tracer particle, dye washout, and dye erosion) was conducted on a sequence of pump designs with varying port locations and diaphragms to improve the geometry with respect to risk of thrombogenesis. Experiments were conducted in a simplified flow loop using occluders to simulate flow resistance induced by tubing and dialyzer. Tracer visualization revealed flow patterns and qualitatively indicated turbulence intensity. Dye washout identified dwell volume and areas of flow stagnation for each design. Dye erosion results indicated the effectiveness and homogeneity of surface washing. Compared to a centered inlet which resulted in a fluid jet that produced two counter-rotating vortices, a tangential inlet introduced a single vortex, and kept the flow laminar. It also provided better surface washing on the pump inner surface. However, a tangential outlet did not present as much benefit as expected. On the contrary, it created a sharp defection to the flow when transiting from filling to ejection.
A Customizable Flow Injection System for Automated, High Throughput, and Time Sensitive Ion Mobility Spectrometry and Mass Spectrometry Measurements.

Science.gov (United States)

Orton, Daniel J; Tfaily, Malak M; Moore, Ronald J; LaMarche, Brian L; Zheng, Xueyun; Fillmore, Thomas L; Chu, Rosalie K; Weitz, Karl K; Monroe, Matthew E; Kelly, Ryan T; Smith, Richard D; Baker, Erin S

2018-01-02

To better understand disease conditions and environmental perturbations, multiomic studies combining proteomic, lipidomic, and metabolomic analyses are vastly increasing in popularity. In a multiomic study, a single sample is typically extracted in multiple ways, and various analyses are performed using different instruments, most often based upon mass spectrometry (MS). Thus, one sample becomes many measurements, making high throughput and reproducible evaluations a necessity. One way to address the numerous samples and varying instrumental conditions is to utilize a flow injection analysis (FIA) system for rapid sample injections. While some FIA systems have been created to address these challenges, many have limitations such as costly consumables, low pressure capabilities, limited pressure monitoring, and fixed flow rates. To address these limitations, we created an automated, customizable FIA system capable of operating at a range of flow rates (∼50 nL/min to 500 μL/min) to accommodate both low- and high-flow MS ionization sources. This system also functions at varying analytical throughputs from 24 to 1200 samples per day to enable different MS analysis approaches. Applications ranging from native protein analyses to molecular library construction were performed using the FIA system, and results showed a highly robust and reproducible platform capable of providing consistent performance over many days without carryover, as long as washing buffers specific to each molecular analysis were utilized.
Two-dimensional versus three-dimensional treatment planning of tangential breast irradiation

International Nuclear Information System (INIS)

Damen, E.M.F.; Bruinvis, I.A.D.; Mijnheer, B.J.

1995-01-01

Purpose: Full three-dimensional (3-D) treatment planning requires 3-D patient contours and density information, derived either from CT scanning or from other 3-D contouring methods. These contouring techniques are time consuming, and are often not available or cannot be used. Two-dimensional (2-D) treatment planning can be performed using only a few patient contours, made with much simpler techniques, in combination with simulator images for estimating the lung position. In order to investigate the need for full 3-D planning, we compared the performance of both a 2-D and a 3-D planning system in calculating absolute dose values and relative dose distributions in tangential breast irradiation. Methods: Two breast-shaped phantoms were used in this study. The first phantom consists of a polyethylene mould, filled with water and cork to mimic the lung. An ionization chamber can be inserted in the phantom at fixed positions. The second phantom is made of 25 transverse slices of polystyrene and cork, made with a computerized milling machine from CT information. In this phantom, films can be inserted in three sagittal planes. Both phantoms have been irradiated with two tangential 8 MV photon beams. The measured dose distribution has been compared with the dose distribution predicted by the two planning systems. Results: In the central plane, the 3-D planning system predicts the absolute dose with an accuracy of 0.5 - 4%. The dose at the isocentre of the beams agrees within 0.5% with the measured dose. The 2-D system predicts the dose with an accuracy of 0.9 - 3%. The dose calculated at the isocentre is 2.6% higher than the measured dose, because missing lateral scatter is not taken into account in this planning system. In off-axis planes, the calculated absolute dose agrees with the measured dose within 4% for the 2-D system and within 6% for the 3-D system. However, the relative dose distribution is predicted better by the 3-D planning system. Conclusions: This study
Flow injection kinetic spectrofluorimetric determination of trace amounts of osmium

Science.gov (United States)

Tang, Bo; Zhang, Hui; Wang, Yan

2005-07-01

A flow injection (FI) kinetic spectrofluorimetric method is described for the determination of osmium(IV) and the possible mechanism of catalytic reaction is discussed. The method is based on the fluorescence enhancing reaction of o-vanillin furfuralhydrazone (OVFH) with potassium bromate, which is catalyzed by Os(IV) in water medium at pH 6.10 and 45 °C. OVFH is newly synthesized and its ionization, IR and elemental analysis are established. Under these experimental conditions, the oxidized product of OVFH has excitation and emission maxima at 337 and 490 nm, respectively. The linear range of this method is 0-600 ng ml -1 with the R.S.D. of 1.2%. The detection limit is 1.0 ng ml -1 of Os(IV). A high analysis rate of 24 samples h -1 is obtained by the FI method. The proposed method is applied successfully to determine Os(IV) in synthetic mixture and mineral samples, and the results are well consistent with the standard values.

DIFFERENTIATION OF AURANTII FRUCTUS IMMATURUS AND FRUCTUS PONICIRI TRIFOLIATAE IMMATURUS BY FLOW-INJECTION WITH ULTRAVIOLET SPECTROSCOPIC DETECTION AND PROTON NUCLEAR MAGNETIC RESONANCE USING PARTIAL LEAST-SQUARES DISCRIMINANT ANALYSIS.

Science.gov (United States)

Zhang, Mengliang; Zhao, Yang; Harrington, Peter de B; Chen, Pei

2016-03-01

Two simple fingerprinting methods, flow-injection coupled to ultraviolet spectroscopy and proton nuclear magnetic resonance, were used for discriminating between Aurantii fructus immaturus and Fructus poniciri trifoliatae immaturus . Both methods were combined with partial least-squares discriminant analysis. In the flow-injection method, four data representations were evaluated: total ultraviolet absorbance chromatograms, averaged ultraviolet spectra, absorbance at 193, 205, 225, and 283 nm, and absorbance at 225 and 283 nm. Prediction rates of 100% were achieved for all data representations by partial least-squares discriminant analysis using leave-one-sample-out cross-validation. The prediction rate for the proton nuclear magnetic resonance data by partial least-squares discriminant analysis with leave-one-sample-out cross-validation was also 100%. A new validation set of data was collected by flow-injection with ultraviolet spectroscopic detection two weeks later and predicted by partial least-squares discriminant analysis models constructed by the initial data representations with no parameter changes. The classification rates were 95% with the total ultraviolet absorbance chromatograms datasets and 100% with the other three datasets. Flow-injection with ultraviolet detection and proton nuclear magnetic resonance are simple, high throughput, and low-cost methods for discrimination studies.
Pellet ablation and cloud flow characteristics in the JIPP T-IIU plasma with the injection-angle controllable system

International Nuclear Information System (INIS)

Sakakita, H.; Sato, K.N.; Liang, R.; Hamada, Y.; Ando, A.; Kano, Y.; Sakamoto, M.

1994-01-01

Pellet ablation and flow characteristics of ablation cloud have been studied in the JIPP T-IIU plasma by using an injection-angle controllable system. A new technique for an ice pellet injection system with controllability of injection angle has been developed and installed to the JIPP T-IIU tokamak in order to vary deposition profile of ice pellets within a plasma. Injection angle can be varied easily and successfully during an interval of two plasma shots in the course of an experiment, so that one can carry out various basic experiments by varying the pellet deposition profile. The injection angle has been varied poloidally from -6 to 6 degree by changing the angle of the last stage drift tube. This situation makes possible for pellets to aim at from about r = -2a/3 to r = 2a/3 of the plasma. From two dimensional observations by CCD cameras, details of the pellet ablation structures with various injection angles have been studied, and a couple of interesting phenomena have been found. In the case of an injection angle (θ) larger than a certain value (θ ≥ 4 o ), a pellet penetrates straightly through the plasma with a trace of straight ablation cloud, which has been expected from usual theoretical consideration. On the other hand, a long helical tail of ablation light has been observed in the case of the angle smaller than the certain value (θ ≤ 4 o ). (author) 4 refs., 4 figs
A comparison of continuous pneumatic nebulization and flow injection-direct injection nebulization for sample introduction in inductively coupled plasma-mass spectrometry

International Nuclear Information System (INIS)

Crain, J.S.; Kiely, J.T.

1995-08-01

Dilute nitric acid blanks and solutions containing Ni, Cd, Pb, and U (including two laboratory waste samples) were analyzed eighteen times over a two-month period using inductively coupled plasma-mass spectrometry (ICP-MS). Two different sample introduction techniques were employed: flow injection-direct injection nebulization (FI-DIN) and continuous pneumatic nebulization (CPN). Using comparable instrumental measurement procedures, FI-DIN analyses were 33% faster and generated 52% less waste than CPN analyses. Instrumental limits of detection obtained with FI-DIN and CPN were comparable but not equivalent (except in the case of Pb) because of nebulizer-related differences in sensitivity (i.e., signal per unit analyte concentration) and background. Substantial and statistically significant differences were found between FI-DIN and CPN Ni determinations, and in the case of the laboratory waste samples, there were also small but statistically significant differences between Cd determinations. These small (2 to 3%) differences were not related to polyatomic ion interference (e.g., 95 Mo 16 O + ), but in light of the time savings and waste reduction to be realized, they should not preclude the use of FI-DIN in place of CPN for determination of Cd, Pb, U and chemically
Numerical investigation on the effect of injection pressure on the internal flow characteristics for diethyl ether, dimethyl ether and diesel fuel injectors using CFD

Directory of Open Access Journals (Sweden)

Vijayakumar Thulasi

2011-01-01

Full Text Available The spray characteristics of the diesel fuel are greatly affected by the cavitation formed inside the injector due to the high pressure differential across the nozzle. Many researchers across the globe are exploring the potential of using diethyl ether and dimethyl ether as an alternate for diesel fuel to meet the strict emission norms. Due to the variation in the fuel properties the internal flow characteristics in injectors for ether fuels are expected to be different from that of the diesel fuel. In this paper computational technique is used to study and compare the internal flow characteristics of diethyl ether, dimethyl ether and diesel fuel. The two phase flow model considering the fuel as a mixture of liquid and vapor is adopted for the simulation study. The injection pressure is varied from 100 to 400 bar and the flow characteristics of all three fuels are simulated and compared. Results indicate that all three fuels have distinct cavitating patterns owing to different property values. The dimethyl ether is found to be more cavitating than diesel and diethyl ether fuels as expected. The mass of fuel injected are found to be decreasing for the ether fuels when compared with diesel fuel at all injection pressures.
Kinetic equilibrium for an asymmetric tangential layer with rotation of the magnetic field

Science.gov (United States)

Belmont, Gérard; Dorville, Nicolas; Aunai, Nicolas; Rezeau, Laurence

2015-04-01

Finding kinetic equilibria for tangential current layers is a key issue for modeling plasma phenomena such as magnetic reconnection instabilities, for which theoretical and numerical studies have to start from steady-state current layers. Until 2012, all theoretical models -starting with the most famous "Harris" one- relied on distribution functions built as mono-valued functions of the trajectories invariants. For a coplanar anti-symmetric magnetic field and in absence of electric field, these models were only able to model symmetric variations of the plasma, so precluding any modeling of "magnetopause-like'' layers, which separate two plasmas of different densities and temperatures. Recently, the "BAS" model was presented (Belmont et al., 2012), where multi-valued functions were taken into account. This new tool is made necessary each time the magnetic field reversal occurs on scales larger than the particle Larmor radii, and therefore guaranties a logical transition with the MHD modeling of large scales. The BAS model so provides a new asymmetric equilibrium. It has been validated in a hybrid simulation by Aunai et al (2013), and more recently in a fully kinetic simulation as well. For this original equilibrium to be computed, the magnetic field had to stay coplanar inside the layer. We present here an important generalization, where the magnetic field rotates inside the layer (although restricted to a 180° rotation hitherto). The tangential layers so obtained are thus closer to those encountered at the real magnetopause. This will be necessary, in the future, for comparing directly the theoretical profiles with the experimental ones for the various physical parameters. As it was done previously, the equilibrium is presently tested with a hybrid simulation. Belmont, G.; Aunai, N.; Smets, R., Kinetic equilibrium for an asymmetric tangential layer, Physics of Plasmas, Volume 19, Issue 2, pp. 022108-022118-10, 2012 Aunai, N.; Belmont, G.; Smets, R., First
Flow-Injection Amperometric Determination of Tacrine based on Ion Transfer across a WaterÃ¢Â€Â“Plasticized Polymeric Membrane Interface

Directory of Open Access Journals (Sweden)

C. Rueda

2007-07-01

Full Text Available A flow-injection pulse amperometric method for determining tacrine, based onion transfer across a plasticized poly(vinyl chloride (PVC membrane, was developed. Afour-electrode potentiostat with ohmic drop compensation was used, while a flow-throughcell incorporated the four electrodes and the membrane, which containedtetrabutylammonium tetraphenylborate. The influence of the applied potential and of theflow-injection variables on the determination of tacrine was studied. In the selectedconditions, a linear relationship between peak height and tacrine concentration was foundup to 4x10-5M tacrine. The detection limit was 1x10-7M. Good repeatability was obtained.Some common ions and pharmaceutical excipients did not interfere.
Remote calorimetric detection of urea via flow injection analysis.

Science.gov (United States)

Gaddes, David E; Demirel, Melik C; Reeves, W Brian; Tadigadapa, Srinivas

2015-12-07

The design and development of a calorimetric biosensing system enabling relatively high throughput sample analysis are reported. The calorimetric biosensor system consists of a thin (∼20 μm) micromachined Y-cut quartz crystal resonator (QCR) as a temperature sensor placed in close proximity to a fluidic chamber packed with an immobilized enzyme. Layer by layer enzyme immobilization of urease is demonstrated and its activity as a function of the number of layers, pH, and time has been evaluated. This configuration enables a sensing system where a transducer element is physically separated from the analyte solution of interest and is thereby free from fouling effects typically associated with biochemical reactions occuring on the sensor surface. The performance of this biosensing system is demonstrated by detection of 1-200 mM urea in phosphate buffer via a flow injection analysis (FIA) technique. Miniaturized fluidic systems were used to provide continuous flow through a reaction column. Under this configuration the biosensor has an ultimate resolution of less than 1 mM urea and showed a linear response between 0-50 mM. This work demonstrates a sensing modality in which the sensor itself is not fouled or contaminated by the solution of interest and the enzyme immobilized Kapton® fluidic reaction column can be used as a disposable cartridge. Such a system enables reuse and reliability for long term sampling measurements. Based on this concept a biosensing system is envisioned which can perform rapid measurements to detect biomarkers such as glucose, creatinine, cholesterol, urea and lactate in urine and blood continuously over extended periods of time.
Preliminary study on functional performance of compound type multistage safety injection tank

International Nuclear Information System (INIS)

Bae, Youngmin; Kim, Young In; Kim, Keung Koo

2015-01-01

Highlights: • Functional performance of compound type multistage safety injection tanks is studied. • Effects of key design parameters are scrutinized. • Distinctive flow features in compound type safety injection tanks are explored. - Abstract: A parametric study is carried out to evaluate the functional performance of a compound type multistage safety injection tank that would be considered one of the components for the passive safety injection systems in nuclear power plants. The effects of key design parameters such as the initial volume fraction and charging pressure of gas, tank elevation, vertical location of a sparger, resistance coefficient, and operating condition on the injection flow rate are scrutinized along with a discussion of the relevant flow features. The obtained results indicate that the compound type multistage safety injection tank can effectively control the injection flow rate in a passive manner, by switching the driving force for the safety injection from gas pressure to gravity during the refill and reflood phases, respectively
Calculation of Flows Over Underwater Bodies with Hull, Sail and Appendages

International Nuclear Information System (INIS)

Shoab, M.; Ayub, M.; Bilal, S.; Zahir, S.; Khan, M.A.

2004-01-01

A comprehensive study has been made for the hydrodynamic analysis of the submarine DARPA 2. The analysis was first performed for hull, then hull with sail on top and then for the complete submarine including hull, sail and appendages. A comparison of tangential velocity and pressure distribution for hull is accomplished using CFD flow solvers and published data. Further, the pressure distribution over the hull with sail is also analyzed. Finally, pressure distribution, forces and moments were calculated over the complete submarine including hull, sail and appendages. Comparison 01 pressure distribution and tangential velocity for the hull show a good agreement with published data. Pressure coefficient comparison for the hull with sail shows the good CFD-CFD agreement. Comparison of Normal force and pitching moment of complete submarine having hull, sail and appendages shows a reasonable agreement with the experimental results of DARPA 2. Both quantitative and qualitative analysis of the complete submarine estimates the required design force and moment at different angles of attack and also demonstrate the flow visualization. (author)
Autologous Pure Platelet-Rich Plasma Dermal Injections for Facial Skin Rejuvenation: Clinical, Instrumental, and Flow Cytometry Assessment.

Science.gov (United States)

Cameli, Norma; Mariano, Maria; Cordone, Iole; Abril, Elva; Masi, Serena; Foddai, Maria Laura

2017-06-01

Platelet-rich plasma (PRP) is an emerging treatment in dermatology recently proposed for skin rejuvenation. To evaluate the efficacy and safety of autologous pure PRP dermal injections on facial skin rejuvenation, investigating the cellularity of PRP samples. Twelve patients underwent 3 sessions of PRP injection at 1-month intervals. The clinical and instrumental outcomes were evaluated before (T0) and 1 month (T1) after the end of treatment by means of transepidermal water loss, corneometry, Cutometer, Visioscan, and Visioface. A flow cytometry characterization on PRP and peripheral blood (PB) samples was performed. Clinical and patient evaluation showed improvement of skin texture. Skin gross elasticity, skin smoothness parameters, skin barrier function, and capacitance were significantly improved. No difference between PRP and PB lymphocyte immunological asset was observed. A leukocyte population (mainly CD3) and neutrophils depletion were documented in all the PRP samples. This instrumental study demonstrated that PRP poor in leukocytes can provide objective improvements in skin biostimulation. Flow cytometry showed no variability among the PRP samples using a reproducible separation system and a low content in proinflammatory cells. Although a pilot study, it may be helpful for future investigations on PRP cellularity.
Determination of Nitrite and Nitrate in Natural Waters Using Flow Injection with Spectrophotometric Detection

International Nuclear Information System (INIS)

Yaqoob, M.; Nabi, A.

2013-01-01

A simple and sensitive flow injection spectrophotometric method is reported for the room temperature determination of nitrite and nitrate based on the Griess reaction and a copperised cadmium column for reduction of nitrate. Calibration graphs were linear over the range 2 - 1000 micro g N L /sup -1/ (R2 = 0.9997 and 0.9999, n = 9) with a limit of detection (3 s.d.) of 1.0 micro g N L and relative standard deviations (n = 10) of 0.9 and 1.2% for 50 micro g N L nitrite and nitrate respectively. The sample throughput was 50 h. The effect of reagent concentrations, physical parameters (flow rate, sample volume, reaction coil and copperised cadmium column length) and the potential interferences are reported. The effect of salinity on the blank and on the determination of nitrite and nitrate are also presented. The method was applied to natural waters (rainwater, freshwater and estuarine water) and the results for nitrite + nitrate (140 - 7310 micro g N L/sup -1/) were not significantly different (95% confidence interval) from results obtained using a segmented flow analyser reference method with spectrophotometric detection. (author)
Control of Surge in Centrifugal Compressor by Using a Nozzle Injection System: Universality in Optimal Position of Injection Nozzle

Directory of Open Access Journals (Sweden)

Toshiyuki Hirano

2012-01-01

Full Text Available The passive control method for surge and rotating stall in centrifugal compressors by using a nozzle injection system was proposed to extend the stable operating range to the low flow rate. A part of the flow at the scroll outlet of a compressor was recirculated to an injection nozzle installed on the inner wall of the suction pipe of the compressor through the bypass pipe and injected to the impeller inlet. Two types of compressors were tested at the rotational speeds of 50,000 rpm and 60,000 rpm with the parameter of the circumferential position of the injection nozzle. The present experimental results revealed that the optimum circumferential position, which most effectively reduced the flow rate for the surge inception, existed at the opposite side of the tongue of the scroll against the rotational axis and did not depend on the compressor system and the rotational speeds.
Can simulation measurements be used to predict the irradiated lung volume in the tangential fields in patients treated for breast cancer

International Nuclear Information System (INIS)

Bornstein, B.A.; Cheng, C.W.; Rhodes, L.M.; Rashid, H.; Stomper, P.C.; Siddon, R.L.; Harris, J.R.

1990-01-01

A simple method of estimating the amount of lung irradiated in patients with breast cancer would be of use in minimizing lung complications. To determine whether simple measurements taken at the time of simulation can be used to predict the lung volume in the radiation field, we performed CT scans as part of treatment planning in 40 cases undergoing radiotherapy for breast cancer. Parameters measured from simulator films included: (a) the perpendicular distance from the posterior tangential field edge to the posterior part of the anterior chest wall at the center of the field (CLD); (b) the maximum perpendicular distance from the posterior tangential field edge to the posterior part of the anterior chest wall (MLD); and (c) the length of lung (L) as measured at the posterior tangential field edge on the simulator film. CT scans of the chest were performed with the patient in the treatment position with 1 cm slice intervals, covering lung apex to base. The ipsilateral total lung area and the lung area included within the treatment port were calculated for each CT scan slice, multiplied by the slice thickness, and then integrated over all CT scan slices to give the volumes. The best predictor of the percent of ipsilateral lung volume treated by the tangential fields was the CLD. Employing linear regression analysis, a coefficient of determination r2 = 0.799 was calculated between CLD and percent treated ipsilateral lung volume on CT scan. In comparison, the coefficients for the other parameters were r2 = 0.784 for the MLD, r2 = 0.071 for L, and r2 = 0.690 for CLD x L. A CLD of 1.5 cm predicted that about 6% of the ipsilateral lung would be included in the tangential field, a CLD of 2.5 cm about 16%, and a CLD of 3.5 cm about 26% of the ipsilateral lung, with a mean 90% prediction interval of +/- 7.1% of ipsilateral lung volume
Viscous slip coefficients for binary gas mixtures measured from mass flow rates through a single microtube

Science.gov (United States)

Yamaguchi, H.; Takamori, K.; Perrier, P.; Graur, I.; Matsuda, Y.; Niimi, T.

2016-09-01

The viscous slip coefficient for helium-argon binary gas mixture is extracted from the experimental values of the mass flow rate through a microtube. The mass flow rate is measured by the constant-volume method. The viscous slip coefficient was obtained by identifying the measured mass flow rate through a microtube with the corresponding analytical expression, which is a function of the Knudsen number. The measurements were carried out in the slip flow regime where the first-order slip boundary condition can be applied. The measured viscous slip coefficients of binary gas mixtures exhibit a concave function of the molar ratio of the mixture, showing a similar profile with numerical results. However, from the detailed comparison between the measured and numerical values with the complete and incomplete accommodation at a surface, it is inappropriate to estimate the viscous slip coefficient for the mixture numerically by employing separately measured tangential momentum accommodation coefficient for each component. The time variation of the molar ratio in the downstream chamber was measured by sampling the gas from the chamber using the quadrupole mass spectrometer. In our measurements, it is indicated that the volume flow rate of argon is larger than that of helium because of the difference in the tangential momentum accommodation coefficient.
Transition from annular flow to plug/slug flow in condensation of steam in microchannels

Energy Technology Data Exchange (ETDEWEB)

Quan, Xiaojun; Cheng, Ping; Wu, Huiying [School of Mechanical and Power Engineering, Shanghai Jiaotong University, 800 Dong Chuan Road, Shanghai 200240 (China)

2008-02-15

A visualization study has been conducted to investigate the transition from annular flow to plug/slug flow in the condensation of steam in two different sets of parallel microchannels, having hydraulic diameters of 90 {mu}m and 136 {mu}m, respectively. The steam in the parallel microchannels was cooled on the bottom by forced convection of water and by natural convection of air from the top. It is found that the location, where the transition from annular flow to plug/slug flow takes place, depends on mass flux and cooling rate of steam. The effects of mass flux and cooling rate on the occurrence frequency of the injection flow in a single microchannel, having a hydraulic diameter of 120 {mu}m and 128 {mu}m, respectively, are investigated. It is found that two different shapes of injection flow occur in the smooth annular flow in microchannels: injection flow with unsteady vapor ligament occurring at low mass flux (or high cooling rate) and injection flow with steady vapor ligament occurring at high mass flux (or low cooling rate). It is also found that increase of steam mass flux, decrease of cooling rate, or decrease of the microchannel diameter tends to enhance instability of the condensate film on the wall, resulting in occurrence of the injection flow further toward the outlet with an increase in occurrence frequency. (author)
Model and simulation for melt flow in micro-injection molding based on the PTT model

International Nuclear Information System (INIS)

Cao, Wei; Kong, Lingchao; Li, Qian; Ying, Jin; Shen, Changyu

2011-01-01

Unsteady viscoelastic flows were studied using the finite element method in this work. The Phan-Thien–Tanner (PTT) model was used to represent the rheological behavior of viscoelastic fluids. To effectively describe the microscale effects, the slip boundary condition and surface tension were added to the mathematical model for melt flow in micro-injection molding. The new variational equation of pressure, including the viscoelastic parameters and slip boundary condition, was generalized using integration by parts. A computer code based on the finite element method and finite difference method was developed to solve the melt flow problem. Numerical simulation revealed that the melt viscoelasticity plays an important role in the prediction of melt pressure, temperature at the gate and the succeeding melt front advancement in the cavity. Using the viscoelastic model one can also control the rapid increase in simulated pressure, temperature, and reduce the filling difference among different cavities. The short shot experiments of micro-motor shaft showed that the predicted melt front from the viscoelastic model is in fair agreement with the corresponding experimental results
The Three-Dimensional Velocity Distribution of Wide Gap Taylor-Couette Flow Modelled by CFD

Directory of Open Access Journals (Sweden)

David Shina Adebayo

2016-01-01

Full Text Available A numerical investigation is conducted for the flow between two concentric cylinders with a wide gap, relevant to bearing chamber applications. This wide gap configuration has received comparatively less attention than narrow gap journal bearing type geometries. The flow in the gap between an inner rotating cylinder and an outer stationary cylinder has been modelled as an incompressible flow using an implicit finite volume RANS scheme with the realisable k-ε model. The model flow is above the critical Taylor number at which axisymmetric counterrotating Taylor vortices are formed. The tangential velocity profiles at all axial locations are different from typical journal bearing applications, where the velocity profiles are quasilinear. The predicted results led to two significant findings of impact in rotating machinery operations. Firstly, the axial variation of the tangential velocity gradient induces an axially varying shear stress, resulting in local bands of enhanced work input to the working fluid. This is likely to cause unwanted heat transfer on the surface in high torque turbomachinery applications. Secondly, the radial inflow at the axial end-wall boundaries is likely to promote the transport of debris to the junction between the end-collar and the rotating cylinder, causing the build-up of fouling in the seal.
Flow injection chemiluminescent determination of N-nitrosodimethylamine using photogenerated tris(2,2'-bipyridyl) ruthenium (III)

International Nuclear Information System (INIS)

Perez-Ruiz, Tomas; Martinez-Lozano, Carmen; Tomas, Virginia; Martin, Jesus

2005-01-01

A flow injection configuration was developed and evaluated for the chemiluminescent determination of N-nitrosodimethylamine. The method is based on the on-line cleavage of the N-NO bond of the nitrosamine by irradiation with ultraviolet light. The dimethylamine generated was subsequently reacted with tris(2,2'-bipyridyl) ruthenium (III), which was generated through the on-line photo-oxidation of tris(2,2'-bipyridyl) ruthenium (II) with peroxydisulfate. After selecting the best operating parameters, the emitted light showed a linear relationship with the concentration of N-nitrosodimethylamine between 1.5 and 148 ng ml -1 , with a detection limit of 0.29 ng ml -1 . The repeatability was 1.6% expressed as relative standard deviation (n = 10) and the reproducibility, studied on five consecutive days, was 3.2%. The sample throughput was 50 injections per hour. The method was applied to studying the recoveries of N-nitrosodimethylamine in water and different cured meat products
[Prophylaxis of recurring low-flow priapism : Experimental botulinum neurotoxin injection into the ischiocavernosus muscle].

Science.gov (United States)

Reichel, G; Stenner, A

2018-01-01

The treatment of recurring low-flow priapism with the usual medications is still unsatisfactory. The case of an otherwise healthy young man experiencing low-flow priapism at the age of 31 is presented. A reason for his condition could not be identified. Over the course of several months, he required emergency urological treatment more than ten times. Treatment with cyproterone acetate (Androcur® 50 mg/day) stopped the spontaneous erections, but resulted in erectile impotence, reduced motivation, decreased interest in sex, weight gain of 10 kg, breast enlargement combined with touch sensitivity on both sides, and hair loss on both legs. In addition, the patient complained about painful cramps in his pelvic muscles. After appropriate explanations he agreed to try botulinum neurotoxin injections into both ischiocavernosus muscles. The objective was to reduce muscle tone in order to improve venous drainage of blood from the penis. The latest relapse of priapism occurred more than 6 months ago.
Flow injection on-line dilution for multi-element determination in human urine with detection by inductively coupled plasma mass spectrometry

DEFF Research Database (Denmark)

Wang, Jianhua; Hansen, Elo Harald; Gammelgaard, Bente

2001-01-01

A simple flow injection on-line dilution procedure with detection by inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of copper, zinc, arsenic, lead, selenium, nickel and molybdenum in human urine. Matrix effects were minimized by employing a dilution factor...

Carbon dioxide fluid-flow modeling and injectivity calculations

Science.gov (United States)

Burke, Lauri

2011-01-01

At present, the literature lacks a geologic-based assessment methodology for numerically estimating injectivity, lateral migration, and subsequent long-term containment of supercritical carbon dioxide that has undergone geologic sequestration into subsurface formations. This study provides a method for and quantification of first-order approximations for the time scale of supercritical carbon dioxide lateral migration over a one-kilometer distance through a representative volume of rock. These calculations provide a quantified foundation for estimating injectivity and geologic storage of carbon dioxide.
Flow injection spectrophotometric determination of Fe(III) and V(v)

International Nuclear Information System (INIS)

Elrahman, Azza Mohamed

2000-01-01

Phenylflourone was synthesized with the objective of developing a method for determining Fe(III) and V(V) in the pressence of micelles using flow injectoin technique. Phenylflourone showed a wavelength of maximum absorption at 412 nm which was not affected by the presence of miccelles i.e. n-hexadodecylpyridinum bromide and sodium n-dodecylsulphate, but they have different effects on the absorbance of PHF. The example of PHF-Fe(III) and PHF-V(V) showed the wavelength of the maximum absorption at 4428 nm and 412 nm, respectively. Presence of micelles shifted the wavelength of the two complexes to a lower one. Generally the addition of micelles increased the absorbance of phenylflourone metal ions complexes except for PHF-V(V) with hexadodecylpyridinum bromide. With flow injection technique two approaches were practiced the use of micelle as a carrier or water as a carrier. Sodium n-dodecylsulphate increased the absorbance of the two complexes when it was used as a carrier or added to the metal ions using water as carrier. On the other hand, the use of n-hexadodecylpyridinum bromide as carrieer increased the absorbance of the complexes but it decreased the absorbance when it was used in conjunction with metal ions and water as a carrier. After establishing the optimum FI conditions for PHF-Fe(III) and PHF-V(V) complexes, the calibration curves were construction and produced semiliner response in the concentration range studied. Ti(IV) III, Mo(VI) showed a positive interference in PHF-Fe(III) and PHF-V(V) complexes, respectively.(Author)
Renal blood flow after selective injection of different dosages of diatrizoate into the renal artery

International Nuclear Information System (INIS)

Burgener, F.A.; Fischer, H.W.; Weber, D.A.

1975-01-01

The characteristic biphasic renal haemodynamic response to diatrizoate injected into the renal artery was shown in the dog with the 133-xenon washout technique. A brief increase in renal blood flow (RBF) during the first ten seconds is followed by a more prolonged period of diminuished RBF. A dose of 4 ml. diatrizoate 60% resulted in the maximum RBF increase of 43% after ten seconds, but even 1 ml. diatrizoate raised the RBF 24%. The initial vasodilator effect of diatrizoate compares well in its extent with the most potent renal vasodilators. (orig.) [de
Comparison between intensity modulated radiotherapy (IMRT) and 3D tangential beams technique used in patients with early-stage breast cancer who received breast-conserving therapy

International Nuclear Information System (INIS)

Sas-Korczynska, B.; Kokoszka, A.; Korzeniowski, S.; Sladowska, A.; Rozwadowska-Bogusz, B.; Lesiak, J.; Dyczek, S.

2010-01-01

Background: The most often found complications in patients with breast cancer who received radiotherapy are cardiac and pulmonary function disorders and development of second malignancies. Aim: To compare the intensity modulated radiotherapy with the 3D tangential beams technique in respect of dose distribution in target volume and critical organs they generate in patients with early-stage breast cancer who received breast-conserving therapy. Materials and methods: A dosimetric analysis was performed to assess the three radiotherapy techniques used in each of 10 consecutive patients with early-stage breast cancer treated with breast-conserving therapy. Radiotherapy was planned with the use of all the three techniques: 3D tangential beams with electron boost, IMRT with electron boost, and intensity modulated radiotherapy with simultaneous integrated boost. Results: The use of the IMRT techniques enables more homogenous dose distribution in target volume. The range of mean and median dose to the heart and lung was lower with the IMRT techniques in comparison to the 3D tangential beams technique. The range of mean dose to the heart amounted to 0.3 - 3.5 Gy for the IMRT techniques and 0.4 - 4.3 for the tangential beams technique. The median dose to the lung on the irradiated side amounted to 4.9 - 5 Gy for the IMRT techniques and 5.6 Gy for the 3D tangential beams technique. Conclusion: The application of the IMRT techniques in radiotherapy patients with early-stage breast cancer allows to obtain more homogenous dose distribution in target volume, while permitting to reduce the dose to critical organs. (authors)
Initial boundary-value problem for the spherically symmetric Einstein equations with fluids with tangential pressure.

Science.gov (United States)

Brito, Irene; Mena, Filipe C

2017-08-01

We prove that, for a given spherically symmetric fluid distribution with tangential pressure on an initial space-like hypersurface with a time-like boundary, there exists a unique, local in time solution to the Einstein equations in a neighbourhood of the boundary. As an application, we consider a particular elastic fluid interior matched to a vacuum exterior.
Neutral beam current drive with balanced injection

International Nuclear Information System (INIS)

Eckhartt, D.

1990-01-01

Current drive with fast ions has proved its capability to sustain a tokamak plasma free of externally induced electric fields in a stationary state. The suprathermal ion population within the toroidal plasma was created by quasi-tangential and uni-directional injection of high-energy neutral atoms, their ionisation and subsequent deceleration by collisions with the background plasma particles. In future large tokamaks of the NET/INTER-type, with reactor-relevant values of plasma density and temperature, this current drive scheme is expected to maintain the toroidal current at the plasma centre, as current drive by lower hybrid waves will be restricted to the outer plasma regions owing to strong wave damping. Adequate penetration of the neutral atoms through the dense plasma requires particle energies of several hundred kilovolts per nucleon since beam absorption scales roughly with the ratio beam energy over density. The realisation of such high-energy high-power neutral beams, based on negative ion technology, is now under study. (author) 7 refs., 2 figs
Process and part filling control in micro injection molding

DEFF Research Database (Denmark)

Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

2008-01-01

The influence of process parameters on μ-injection molding (μIM) and on μ-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers...... position was measured on the polymer μ-parts to evaluate filling behavior of the polymer melt flowing through μ-features. Experimental results obtained under different processing conditions were evaluated to correlate the process parameter levels influence on the selected responses. Results showed...... that the injection speed in one of the most influencing process parameters on the μIM process and on the μ-parts filling....
On the effect of a tangential discontinuity on ions specularly reflected at an oblique shock

International Nuclear Information System (INIS)

Burgess, D.

1989-01-01

In seeking to explain the events observed close to the Earth's bow shock known as hot, diamagnetic cavities (HDC), or active current sheets (ACS), attention has focused on the microphysics of the interaction of a magnetic field directional discontinuity and a collisionless, supercritical shock. Here the author investigates the case of a tangential discontinuity (TD) convecting into a shock at some arbitrary angle. As a first stage he adopted an approach in which test particles represent ions specularly reflected at the shock front. Widely different behavior is possible depending on the sense of ion gyration relative to the TD. Particles can be injected into the plane of the TD so that they travel upstream trapped close to the TD. This implies that ACS events, presumed to be the result of the interaction of the solar wind with a large density reflected component, are detached from the bow shock. For other geometries, ions interact with the TD but stay close to the shock, implying that ACS events are modifications of the shock. The TD can deprive a limited spatial region of a downstream reflected gyrating ion population (necessary for the quasi-perpendicular supercritical shock to be steady), and so he could anticipate where the shock will not be in equilibrium, and consequently where strong reflection may occur. The detailed behavior of the shock in such a situation must be investigated with self-consistent simulations
Investigation the effects of injection pressure and compressibility and nozzle entry in diesel injector nozzle’s flow

Directory of Open Access Journals (Sweden)

Seyed mohammadjavad Zeidi

2015-04-01

Full Text Available Investigating nozzle’s orifice flow is challenging both experimentally and theoretically. This paper focuses on simulating flow inside diesel injector nozzle via Ansys fluent v15. Validation is performed with experimental results from Winkhofler et al (2001. Several important parameters such as mass flow rate, velocity profiles and pressure profiles are used for this validation. Results include the effects of contraction inside nozzle’s orifice, effect of compressibility; effect of injection pressures and several orifice entries are also simulated in this study. For considering the effect of compressibility a user defined function used in this simulation. Cavitation model which is used in this simulation is Singhal et al. cavitation model. Presto discretization method is used for Pressure equation and second upwind discretization method is used for Momentum equation. Converging Singhal et al. cavitation model is very challenging and it needs several efforts and simulations.
Fabrication of an Amperometric Flow-Injection Microfluidic Biosensor Based on Laccase for In Situ Determination of Phenolic Compounds

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Juan C. Gonzalez-Rivera

2015-01-01

Full Text Available We aim to develop an in situ microfluidic biosensor based on laccase from Trametes pubescens with flow-injection and amperometry as the transducer method. The enzyme was directly immobilized by potential step chronoamperometry, and the immobilization was studied using cyclic voltammetry and electrochemical impedance spectroscopy. The electrode response by amperometry was probed using ABTS and syringaldazine. A shift of interfacial electron transfer resistance and the electron transfer rate constant from 18.1 kΩ to 3.9 MΩ and 4.6 × 10−2 cm s−1 to 2.1 × 10−4 cm s−1, respectively, evidenced that laccase was immobilized on the electrode by the proposed method. We established the optimum operating conditions of temperature (55°C, pH (4.5, injection flow rate (200 µL min−1, and applied potential (0.4 V. Finally, the microfluidic biosensor showed better lower limit of detection (0.149 µM and sensitivity (0.2341 nA µM−1 for ABTS than previous laccase-based biosensors and the in situ operation capacity.
Purged window apparatus utilizing heated purge gas

Science.gov (United States)

Ballard, Evan O.

1984-01-01

A purged window apparatus utilizing tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows, and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube. Use of this apparatus prevents backstreaming of gases under investigation which are flowing past the mouth of the mounting tube which would otherwise deposit on the windows. Lengthy spectroscopic investigations and analyses can thereby be performed without the necessity of interrupting the procedures in order to clean or replace contaminated windows.
Flow injection analysis of sulphide based on its photoelectrocatalytic oxidation at poly-methylene blue modified glassy carbon electrode

International Nuclear Information System (INIS)

Dilgin, Yusuf; Canarslan, Seda; Ayyildiz, Onder; Ertek, Bensu; Nişli, Gürel

2012-01-01

A new approach for photoelectrocatalytic determination of sulphide in a flow injection analysis (FIA) system was studied using a poly-methylene blue modified glassy carbon electrode (poly-MB/GCE). Results from electrochemical measurements have revealed that poly-MB/GCE is capable of signalling electrocatalytic and photoelectrocatalytic activity towards sulphide oxidation. When the surface of poly-MB/GCE was irradiated with a light source (250 W Halogen lamp), the electrocatalytic current increased substantially. A homemade flow electrochemical cell with a suitable transparent window for the irradiation of the electrode surface was used to perform the photoelectrocatalytic determination of sulphide in FIA system. The currents obtained from the photoamperometric measurements in the FIA system at optimum conditions (carrier solution: pH 9.0 Britton Robinson buffer solution containing 0.1 M KCl; flow rate: 1.3 mL min −1 ; transmission tubing length: 10 cm; injection volume: 100 μL; and constant applied potential: +150 mV vs. Ag/AgCl/KCl sat ) were linearly correlated with the sulphide concentration. The calibration curves were obtained for sulphide concentrations in a range of 0.5–500 μM. The detection limits were found to be 0.27 and 0.15 μM for amperometric and photoamperometric methods, respectively. The proposed method was successfully applied to different wastewaters such as municipal sewage or tannery wastewater. Finally, results from the sulphide measurements by poly-MB/GCE were in good agreement with those attained using spectrophotometric method.
Slideline verification for multilayer pressure vessel and piping analysis including tangential motion

International Nuclear Information System (INIS)

Van Gulick, L.A.

1984-01-01

Nonlinear finite element method (FEM) computer codes with slideline algorithm implementations should be useful for the analysis of prestressed multilayer pressure vessels and piping. This paper presents closed form solutions including the effects of tangential motion useful for verifying slideline implementations for this purpose. The solutions describe stresses and displacements of a long internally pressurized elastic-plastic cylinder initially separated from an elastic outer cylinder by a uniform gap. Comparison of closed form and FEM results evaluates the usefulness of the closed form solution and the validity of the sideline implementation used
Tangential boundary values of Laplace transforms. Applications to Muntz-Szasz type approximation

Science.gov (United States)

Sedletskii, A. M.

2003-02-01

We consider the Laplace transforms (LT) of functions in L^q(\\mathbb R_+), 1, with a slowly varying weight. We prove that if the weight satisfies certain conditions, then each LT of this class has tangential boundary values almost everywhere on the imaginary axis, and the structure of the corresponding neighbourhoods depends on the weight only. This result is applied to distinguish a wide class of weighted L^p spaces on the half-line such that the Szasz condition is not necessary for the completeness of the system \\exp(-\\lambda_n t) in these spaces.
Determination of uranium in organic phase by flow injection spectrophotometric analysis

International Nuclear Information System (INIS)

Yu Yiyun

1998-01-01

Based on the use of merging zone circuit and simulating a series of standard solution of uranium in organic phase, uranium in unknown organic phase sample was determined by flow injection spectrophotometry. A linear calibration graph was obtained with correlation coefficient of 0.999 for uranium concentration in organic phase over 10∼200 mg/L. Isopropyl alcohol was used as carrier solution. Mixing colour solution contains isopropyl alcohol, triethanolamine, masking reagent and Br-PADAP. The relative standard deviation of the method was better than +-5%. Determination of each sample can be completed in one minute. The method characteristic is: (1) using merging zone and simulating standard solution of uranium in organic phase, the method is sensitive and reliable; (2) even if the determined solution was in turbid condition, it can be quantitatively determined; (3) by means of solution replace technique, the tube of peristaltic pump can be used over a long period of time
Flow-injection determination of thorium and uranium after on-line ion-exchange preconcentration in Dowex 50-X8

International Nuclear Information System (INIS)

Perez Pavon, J.L.; Garcia Pinto, C.G.; Rodriguez Garcia, Estrella; Moreno Cordero, Bernardo

1992-01-01

The preconcentration of thorium and uranium on Dowex 50-X8 was studied as a method for the preconcentration of these cations prior to their determination by flow injection with spectrophotometric detection using Arsenazo III in 3.6 M HCl stabilized with Triton X-100 as chromogenic reagent. The preconcentration device is a minicolumn included in the sample loop of the injection valve. A second valve contains a reducing minicolumn filled with lead powder to reduce U(VI) to U(IV) before the confluence of the sample with the reagent stream. The method can be applied to samples containing 0.5-100 μg l -1 and was tested with different spiked water samples. (author). 15 refs.; 3 figs.; 3 tabs
Gaseous slip flow analysis of a micromachined flow sensor for ultra small flow applications

Science.gov (United States)

Jang, Jaesung; Wereley, Steven T.

2007-02-01

The velocity slip of a fluid at a wall is one of the most typical phenomena in microscale gas flows. This paper presents a flow analysis considering the velocity slip in a capacitive micro gas flow sensor based on pressure difference measurements along a microchannel. The tangential momentum accommodation coefficient (TMAC) measurements of a particular channel wall in planar microchannels will be presented while the previous micro gas flow studies have been based on the same TMACs on both walls. The sensors consist of a pair of capacitive pressure sensors, inlet/outlet and a microchannel. The main microchannel is 128.0 µm wide, 4.64 µm deep and 5680 µm long, and operated under nearly atmospheric conditions where the outlet Knudsen number is 0.0137. The sensor was fabricated using silicon wet etching, ultrasonic drilling, deep reactive ion etching (DRIE) and anodic bonding. The capacitance change of the sensor and the mass flow rate of nitrogen were measured as the inlet-to-outlet pressure ratio was varied from 1.00 to 1.24. The measured maximum mass flow rate was 3.86 × 10-10 kg s-1 (0.019 sccm) at the highest pressure ratio tested. As the pressure difference increased, both the capacitance of the differential pressure sensor and the flow rate through the main microchannel increased. The laminar friction constant f sdot Re, an important consideration in sensor design, varied from the incompressible no-slip case and the mass sensitivity and resolution of this sensor were discussed. Using the current slip flow formulae, a microchannel with much smaller mass flow rates can be designed at the same pressure ratios.
Espectrofotometria de zinco em fertilizantes em fluxo Flow injection spectrophotometry of zinc in mineral fertilizers

Directory of Open Access Journals (Sweden)

Arnaldo Antonio Rodella

1999-07-01

Full Text Available Um sistema de análise química por injeção em fluxo é proposto para a determinação espectrofotométrica de zinco em amostras de misturas de fertilizantes minerais, empregando-se zincon como reagente cromogênico. O procedimento analítico envolve redução de íons metálicos por ácido ascórbico, complexação com íon cianeto, seguindo-se a descomplexação seletiva do zinco com formaldeído, liberando-o para que reaja com o zincon formando um complexo azul. A aplicação do método proposto à extratos de mistura de fertilizantes indicou que a ação de interferentes pode ser contornada e que resultados comparáveis aos da espectrometria de absorção atômica são obtidos.A flow injection system for zinc analysis in mineral fertilizer mixtures is proposed using zincon as chromogenic reagent. The effect of interfering ions such as Cu2+, Fe3+, Mn2+ was eliminated by reduction (using ascorbic acid and complexation of these metal íons with cyanide, with zinc included. Zinc is allowed to react with zincon only after the destruction of the zinc cyano complex with formaldehyde. Flow injection analysis permitted efficient control of the reaction time so that only the zinc ion is set free to produce a blue complex with zincon. Zinc was determined in 16 fertilizer mixtures (3 replicates with precision and accuracy comparable to atomic absorption spectrometry.
The estimation of tissue loss during tangential hydrosurgical debridement.

Science.gov (United States)

Matsumura, Hajime; Nozaki, Motohiro; Watanabe, Katsueki; Sakurai, Hiroyuki; Kawakami, Shigehiko; Nakazawa, Hiroaki; Matsumura, Izumi; Katahira, Jiro; Inokuchi, Sadaki; Ichioka, Shigeru; Ikeda, Hiroto; Mole, Trevor; Smith, Jennifer; Martin, Robin; Aikawa, Naoki

2012-11-01

The preservation of healthy tissue during surgical debridement is desirable as this may improve clinical outcomes. This study has estimated for the first time the amount of tissue lost during debridement using the VERSAJET system of tangential hydrosurgery. A multicenter, prospective case series was carried out on 47 patients with mixed wound types: 21 (45%) burns, 13 (28%) chronic wounds, and 13 (28%) acute wounds. Overall, 44 (94%) of 47 patients achieved appropriate debridement after a single debridement procedure as verified by an independent photographic assessment. The percentage of necrotic tissue reduced from a median of 50% to 0% (P < 0.001). Median wound area and depth increased by only 0.3 cm (6.8%) and 0.5 mm (25%), respectively. Notably, 43 (91%) of 47 wounds did not progress into a deeper compartment, indicating a high degree of tissue preservation.
The determination of levofloxacin by flow injection analysis using UV detection, potentiometry, and conductometry in pharmaceutical preparations.

Science.gov (United States)

Altiokka, G; Atkosar, Z; Can, N O

2002-10-15

A flow injection analysis (FIA) using UV detection, potentiometry and conductometry for levofloxacin (LVF) are described in this study. The best solvent system was found to consist of 0.2 M acetate buffer at pH 3 having 10% MeOH. A flow rate of 1 ml min(-1) was pumped and active material was detected at 288 nm. The detection limit (LOD) and limit of quantification (LOQ) for FIA were calculated to be 3 x 10(-7) M (S/N = 3) and 1 x 10(-7) M (S/N = 10), respectively. In the analysis of tablets, the RSD values were found to be 0.83, 0.98 and 0.99 for FIA, potentiometric and conductometric methods, respectively. Copyright 2002 Elsevier Science B.V.

Investigation on the Flow in a Rotor-Stator Cavity with Centripetal Through-Flow

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Bo Hu

2017-10-01

Full Text Available Daily and Nece distinguished four flow regimes in an enclosed rotor-stator cavity, which are dependent on the circumferential Reynolds number and dimensionless axial gap width. A diagram of the different flow regimes including the respective mean profiles for both tangential and radial velocity was developed. The coefficients for the different flow regimes have also been correlated. In centrifugal pumps and turbines, the centripetal through-flow is quite common from the outer radius of the impeller to the impeller eye, which has a strong influence on the radial pressure distribution, axial thrust and frictional torque. The influence of the centripetal through-flow on the cavity flow with different circumferential Reynolds numbers and dimensionless axial gap width is not sufficiently investigated. It is also quite important to convert the 2D Daily and Nece diagram into 3D by introducing the through-flow coefficient. In order to investigate the impact of the centripetal through-flow, a test rig is designed and built up at the University of Duisburg-Essen. The design of the test rig is described. The impact of the above mentioned parameters on the velocity profile, pressure distribution, axial thrust and frictional torque are presented and analyzed in this paper. The 3D Daily and Nece diagram introducing the through-flow coefficient is also organized in this paper.
Status of Far Infrared Tangential Interferometry/Polarimetry (FIReTIP) on NSTX

International Nuclear Information System (INIS)

Park, H.K.; Edwards, S.; Guttadora, L.; Deng, B.; Domier, C.W.; Lee, K.C.; Johnson, M.; Luhmann, N.C. Jr.

2000-01-01

The Influence of paramagnetism and diamagnetism will significantly alter the vacuum toroidal magnetic field in the spherical torus. Therefore, plasma parameters dependent upon BT such as the q-profile and the local b value need an independent measurement of BT(r,t). The multi-chord Tangential Far Infrared Interferometer/Polarimeter (FIReTIP) system [1] currently under development for the National Spherical Torus Experiment (NSTX) will provide temporally and radially resolved toroidal field profile [BT(r,t)] and 2-D electron density profile [ne(r,t)] data. A two-channel interferometer will be operational this year and the full system will be ready by 2002
Far-infrared tangential interferometer/polarimeter design and installation for NSTX-U

Energy Technology Data Exchange (ETDEWEB)

Scott, E. R., E-mail: evrscott@ucdavis.edu [Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616 (United States); Barchfeld, R. [Department of Applied Science, University of California, Davis, California 95616 (United States); Riemenschneider, P.; Domier, C. W.; Sohrabi, M.; Luhmann, N. C. [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Muscatello, C. M. [General Atomics, San Diego, California 92121 (United States); Kaita, R.; Ren, Y. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

2016-11-15

The Far-infrared Tangential Interferometer/Polarimeter (FIReTIP) system has been refurbished and is being reinstalled on the National Spherical Torus Experiment—Upgrade (NSTX-U) to supply real-time line-integrated core electron density measurements for use in the NSTX-U plasma control system (PCS) to facilitate real-time density feedback control of the NSTX-U plasma. Inclusion of a visible light heterodyne interferometer in the FIReTIP system allows for real-time vibration compensation due to movement of an internally mounted retroreflector and the FIReTIP front-end optics. Real-time signal correction is achieved through use of a National Instruments CompactRIO field-programmable gate array.
Flow injection chemiluminescence determination of lercanidipine based on N-chlorosuccinimide-eosin Y post-chemiluminescence reaction.

Science.gov (United States)

Wang, Guowei; Zhao, Fang; Gao, Ying

2014-12-01

A novel post-chemiluminescence (PCL) reaction was discovered when lercanidipine was injected into the CL reaction mixture of N-chlorosuccinimide with alkaline eosin Y in the presence of cetyltrimethylammonium bromide (CTAB), where eosin Y was used as the CL reagent and CTAB as the surfactant. Based on this observation, a simple and highly sensitive PCL method combined with a flow injection (FI) technique was developed for the assay of lercanidipine. Under optimum conditions, the CL signal was linearly related to the concentration of lercanidipine in the range 7.0 × 10(-10) to 3.0 × 10(-6) g/mL with a detection limit of 2.3 × 10(-10) g/mL (3σ). The relative standard deviation (RSD) was 2.1% for 1.0 × 10(-8) g/mL lercanidipine (n = 13). The proposed method had been applied to the estimation of lercanidipine in tablets and human serum samples with satisfactory results. The possible CL mechanism is also discussed briefly. Copyright © 2014 John Wiley & Sons, Ltd.
Simulation of Spray Injection in the Pressurizer Using RELAP5

Directory of Open Access Journals (Sweden)

S. Dibyo

2017-08-01

Full Text Available A modeling research using Relap5 to assess the pressurizer of a pressurized water reactor(PWR power plant has been performed. The heater and water injection systems in the pressurizer system of the PWRare of greatimportance for system pressure control.The heater is designed to increase the pressure while the water sprayer injection is to perform depressurization. Most of studies conducted in the past mainly focused on determining the effects of nozzle spray design and droplet size using testing loops. The purpose of this simulation is to analyze the spray injection flow rate against the pressure characteristics of the pressurizer using RELAP5. Through this approach, the optimum injection flow rate of full scale plant pressurizer can be analyzed. The parameters investigated are pressure and temperature.In RELAP5, the pressurizer tank wasmodeled with six volume nodes and the heater was modeled by using heat structure. In the model, the sprayer takes water from the cold leg to inject it into the top of tank region.The resultsshowedthat the mass flow of about 4 kg/s is the mosteffectivevalueto limit pressure in the pressurizer to below 15.7 MPa. However, the flow rates of 8 kg/s and more cause overpressure. This simulation is usefulto complement the data related to the water flow rate injection systems of the pressurizer. Normal 0 false false false EN-US X-NONE X-NONE Viscous hydrophilic injection matrices for serial crystallography

Directory of Open Access Journals (Sweden)

Gabriela Kovácsová

2017-07-01

Full Text Available Serial (femtosecond crystallography at synchrotron and X-ray free-electron laser (XFEL sources distributes the absorbed radiation dose over all crystals used for data collection and therefore allows measurement of radiation damage prone systems, including the use of microcrystals for room-temperature measurements. Serial crystallography relies on fast and efficient exchange of crystals upon X-ray exposure, which can be achieved using a variety of methods, including various injection techniques. The latter vary significantly in their flow rates – gas dynamic virtual nozzle based injectors provide very thin fast-flowing jets, whereas high-viscosity extrusion injectors produce much thicker streams with flow rates two to three orders of magnitude lower. High-viscosity extrusion results in much lower sample consumption, as its sample delivery speed is commensurate both with typical XFEL repetition rates and with data acquisition rates at synchrotron sources. An obvious viscous injection medium is lipidic cubic phase (LCP as it is used for in meso membrane protein crystallization. However, LCP has limited compatibility with many crystallization conditions. While a few other viscous media have been described in the literature, there is an ongoing need to identify additional injection media for crystal embedding. Critical attributes are reliable injection properties and a broad chemical compatibility to accommodate samples as heterogeneous and sensitive as protein crystals. Here, the use of two novel hydrogels as viscous injection matrices is described, namely sodium carboxymethyl cellulose and the thermo-reversible block polymer Pluronic F-127. Both are compatible with various crystallization conditions and yield acceptable X-ray background. The stability and velocity of the extruded stream were also analysed and the dependence of the stream velocity on the flow rate was measured. In contrast with previously characterized injection media, both new
Flow injection on-line spectrophotometric determination of thorium(IV) after preconcentration on XAD-4 resin impregnated with oxytetracycline

Energy Technology Data Exchange (ETDEWEB)

Shahida, Shabnam; Khan, Muhammad Haleem [Univ. of Azad Jammu and Kashmir, Muzaffarabad (Pakistan). Dept. of Chemistry; Ali, Akbar [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Chemistry Div.

2014-02-15

A very sensitive, selective and simple flow injection time-based method was developed for on-line preconcentration and determination of thorium(IV) at micro g L{sup -1} levels in environmental samples. The system operation was based on thorium(IV) ion retention at pH 4.0 in the minicolumn at a flow rate of 15.2 mL min{sup -1}. The trapped complex was then eluted with 3.6 mol L{sup -1} HCl at a flow rate of 4.9 mL min{sup -1}. The amount of thorium(IV) in the eluate was measured spectrophotometrically at 651 nm using arsenazo-III solution (0.05 % in 3.6 mol L{sup -1} HCl stabilized with 1 % triton X-100, 4.9 mL min{sup -1}) as colorimetric reagent. All chemical, and flow injection variables were optimized for the quantitative preconcentration of metal and a study of interference level of various ions was also carried out. The system offered low backpressure and improved sensitivity and selectivity. At a preconcentration time of 60 s and a sample frequency of 40 h{sup -1}, the enhancement factor was 97, the detection limit was 0.25 μg L{sup -1}, and the precision expressed as relative standard deviation was 1.08 % (at 50 μg L{sup -1}), whereas for 300 s of the preconcentration time and a sample frequency of 10 h{sup -1}, the enhancement factor of 357, the detection limit (3s) of 0.069 μg L{sup -1} and the precision of 1.32 % (at 10 μg L{sup -1}) was reported. The accuracy of the developed method was sufficient and evaluated by the analysis of certified reference material IAEA-SL-1 (Lake Sediment) and spiked water samples.
Flow injection on-line spectrophotometric determination of thorium(IV) after preconcentration on XAD-4 resin impregnated with oxytetracycline

International Nuclear Information System (INIS)

Shahida, Shabnam; Khan, Muhammad Haleem; Ali, Akbar

2014-01-01

A very sensitive, selective and simple flow injection time-based method was developed for on-line preconcentration and determination of thorium(IV) at micro g L"-"1 levels in environmental samples. The system operation was based on thorium(IV) ion retention at pH 4.0 in the minicolumn at a flow rate of 15.2 mL min"-"1. The trapped complex was then eluted with 3.6 mol L"-"1 HCl at a flow rate of 4.9 mL min"-"1. The amount of thorium(IV) in the eluate was measured spectrophotometrically at 651 nm using arsenazo-III solution (0.05 % in 3.6 mol L"-"1 HCl stabilized with 1 % triton X-100, 4.9 mL min"-"1) as colorimetric reagent. All chemical, and flow injection variables were optimized for the quantitative preconcentration of metal and a study of interference level of various ions was also carried out. The system offered low backpressure and improved sensitivity and selectivity. At a preconcentration time of 60 s and a sample frequency of 40 h"-"1, the enhancement factor was 97, the detection limit was 0.25 μg L"-"1, and the precision expressed as relative standard deviation was 1.08 % (at 50 μg L"-"1), whereas for 300 s of the preconcentration time and a sample frequency of 10 h"-"1, the enhancement factor of 357, the detection limit (3s) of 0.069 μg L"-"1 and the precision of 1.32 % (at 10 μg L"-"1) was reported. The accuracy of the developed method was sufficient and evaluated by the analysis of certified reference material IAEA-SL-1 (Lake Sediment) and spiked water samples.
Numerical simulation in steam injection process by a mechanistic approach

Energy Technology Data Exchange (ETDEWEB)

De Souza, J.C.Jr.; Campos, W.; Lopes, D.; Moura, L.S.S. [Petrobras, Rio de Janeiro (Brazil)

2008-10-15

Steam injection is a common thermal recovery method used in very viscous oil reservoirs. The method involves the injection of heat to reduce viscosity and mobilize oil. A steam generation and injection system consists primarily of a steam source, distribution lines, injection wells and a discarding tank. In order to optimize injection and improve the oil recovery factor, one must determine the parameters of steam flow such as pressure, temperature and steam quality. This study focused on developing a unified mathematical model by means of a mechanistic approach for two-phase steam flow in pipelines and wells. The hydrodynamic and heat transfer mechanistic model was implemented in a computer simulator to model the parameters of steam injection while trying to avoid the use of empirical correlations. A marching algorithm was used to determine the distribution of pressure and temperature along the pipelines and wellbores. The mathematical model for steam flow in injection systems, developed by a mechanistic approach (VapMec) performed well when the simulated values of pressures and temperatures were compared with the values measured during field tests. The newly developed VapMec model was incorporated in the LinVap-3 simulator that constitutes an engineering supporting tool for steam injection wells operated by Petrobras. 23 refs., 7 tabs., 6 figs.
Current Profile and Magnetic Structure Measurements through Tangential Soft X-Ray Imaging in Compact Tori

International Nuclear Information System (INIS)

Fonck, Raymond J.

2004-01-01

This report describes the fabrication and tests of a tangentially imaging soft X-ray (SXR) camera diagnostic for fusion energy plasma research. It can be used for the determination of the current distribution in strongly shaped toroidal magnetically confined plasmas, such as those found in spherical tori or advanced tokamaks. It included the development of both an appropriate imaging SXR camera and image analysis techniques necessary to deduce the plasma shape and current distribution. The basic camera concept consists of a tangentially viewing pinhole imaging system with thin-film SXR filters, a scintillator screen to provide SXR to visible conversion, a fast shuttering system, and an sensitive visible camera imaging device. The analysis approach consists of integrating the 2-D SXR image data into a Grad-Shafranov toroidal equilibrium solver code to provide strong constraints on the deduced plasma current and pressure profiles. Acceptable sensitivity in the deduced current profile can be obtained if the relative noise in the measured image can be kept in the range of 1% or less. Tests on the Pegasus Toroidal Experiment indicate very flat safety factor profiles in the plasma interior
Estimation of Power Consumption in the Circular Sawing of Stone Based on Tangential Force Distribution

Science.gov (United States)

Huang, Guoqin; Zhang, Meiqin; Huang, Hui; Guo, Hua; Xu, Xipeng

2018-04-01

Circular sawing is an important method for the processing of natural stone. The ability to predict sawing power is important in the optimisation, monitoring and control of the sawing process. In this paper, a predictive model (PFD) of sawing power, which is based on the tangential force distribution at the sawing contact zone, was proposed, experimentally validated and modified. With regard to the influence of sawing speed on tangential force distribution, the modified PFD (MPFD) performed with high predictive accuracy across a wide range of sawing parameters, including sawing speed. The mean maximum absolute error rate was within 6.78%, and the maximum absolute error rate was within 11.7%. The practicability of predicting sawing power by the MPFD with few initial experimental samples was proved in case studies. On the premise of high sample measurement accuracy, only two samples are required for a fixed sawing speed. The feasibility of applying the MPFD to optimise sawing parameters while lowering the energy consumption of the sawing system was validated. The case study shows that energy use was reduced 28% by optimising the sawing parameters. The MPFD model can be used to predict sawing power, optimise sawing parameters and control energy.
Enchancing the use of coal by gas reburning and sorben injection

International Nuclear Information System (INIS)

Keen, R.T.; Hong, C.C.; Opatrny, J.C.; Sommer, T.M.; Folsom, B.A.; Payne, R.; Ritz, H.J.; Pratapas, J.M.; May, T.J.; Krueger, M.S.

1993-01-01

The Gas Reburning-Sorbent Injection (GR-SI) Process was demonstrated on a 71 MWe net tangentially fired boiler at Hennepin, Illinois, and is being demonstrated on a 33 MWe net cyclone-fired boiler at Springfield, Illinois as a Clean Coal Technology Round I demonstration project. The Hennepin demonstration was completed after more than 2,000 hours of successful operation. In long-term demonstration testing at a Ca/S molar ratio of 1.75 an 19 percent gas heat input, 53 percent SO 2 reduction and 67 percent NO x reduction were achieved without any adverse impacts on boiler performance or electrostatic precipitator performance with flue gas humidification. These achievements exceeded the project goals of 50 and 60 percent, respectively. The CO 2 reduction due to the use of 18 percent natural gas was 8 percent
Porous media heat transfer for injection molding

Science.gov (United States)

Beer, Neil Reginald

2016-05-31

The cooling of injection molded plastic is targeted. Coolant flows into a porous medium disposed within an injection molding component via a porous medium inlet. The porous medium is thermally coupled to a mold cavity configured to receive injected liquid plastic. The porous medium beneficially allows for an increased rate of heat transfer from the injected liquid plastic to the coolant and provides additional structural support over a hollow cooling well. When the temperature of the injected liquid plastic falls below a solidifying temperature threshold, the molded component is ejected and collected.
An experimental investigation of pneumatic swirl flow induced by a three lobed helical pipe

International Nuclear Information System (INIS)

Fokeer, S.; Lowndes, I.; Kingman, S.

2009-01-01

This paper presents a discussion of the results and conclusions drawn from a series of experiments conducted to investigate the swirl flow that are generated by a three lobed helical pipe mounted within a laboratory scale pneumatic conveying rig. The experiments employed Laser Doppler Anemometry (LDA) to quantify the strength of the induced vortex formations and the decay rates of the observed downstream swirl flows over a range of Reynolds number in the turbulent regime. Instantaneous point velocity measurements were resolved in three directions across regular measurement grids transcribed across parallel planes located at four distances downstream of the swirl inducing pipe section. The equivalent axial, radial and tangential velocities were subsequently computed at these grids points. The degree of swirl measured across each measurement plane was expressed in terms of a defined swirl number. It was concluded that the three lobed helical pipe gave rise to a wall jet type of swirl whose rate of observed downstream decay is related to the Reynolds number of the upstream flow and the distance downstream of the swirl pipe. The decay rates for the swirl flows were found to be inversely proportional to the Reynolds number of the upstream flow. The swirl pipe was observed to create a redistribution of the downstream velocity field from axial to tangential, accompanied by a transfer of axial to angular momentum. The findings of this paper are believed to improve understanding to assist the selective use of swirl flow within lean phase particles pneumatic transport systems.
An experimental investigation of pneumatic swirl flow induced by a three lobed helical pipe

Energy Technology Data Exchange (ETDEWEB)

Fokeer, S. [Department of Aeronautical and Automotive Engineering, University of Loughborough LE11 3TU (United Kingdom)], E-mail: S.Fokeer@lboro.ac.uk; Lowndes, I.; Kingman, S. [Division of Process and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

2009-04-15

This paper presents a discussion of the results and conclusions drawn from a series of experiments conducted to investigate the swirl flow that are generated by a three lobed helical pipe mounted within a laboratory scale pneumatic conveying rig. The experiments employed Laser Doppler Anemometry (LDA) to quantify the strength of the induced vortex formations and the decay rates of the observed downstream swirl flows over a range of Reynolds number in the turbulent regime. Instantaneous point velocity measurements were resolved in three directions across regular measurement grids transcribed across parallel planes located at four distances downstream of the swirl inducing pipe section. The equivalent axial, radial and tangential velocities were subsequently computed at these grids points. The degree of swirl measured across each measurement plane was expressed in terms of a defined swirl number. It was concluded that the three lobed helical pipe gave rise to a wall jet type of swirl whose rate of observed downstream decay is related to the Reynolds number of the upstream flow and the distance downstream of the swirl pipe. The decay rates for the swirl flows were found to be inversely proportional to the Reynolds number of the upstream flow. The swirl pipe was observed to create a redistribution of the downstream velocity field from axial to tangential, accompanied by a transfer of axial to angular momentum. The findings of this paper are believed to improve understanding to assist the selective use of swirl flow within lean phase particles pneumatic transport systems.
A Simple and Rapid Flow-Injection Chemiluminescence Method for the Determination of Noscapine with Ru(phen)32+-Ce(4) System

International Nuclear Information System (INIS)

Rezaei, B.; Mokhtari, A.; Khayamian, T.

2007-01-01

A new flow injection chemiluminescence (CL) system was used for the determination of noscapine. This technique is based on the reduction effect of noscapine on the Ru(phen) 3 3+ , which is produced by reaction between Ru(phen) 3 2+ and acidic Ce(4) solutions, and this rapid reduction produces strong CL. Calibration plots were linear over the range of 3.0x10 -7 -2.0x10 -6 mol L -1 and 2.0x10 -6 -2.0x10 -4 mol L -1 . The CL intensity was so high, that it is able to produce a detection limit of 6.6x10 -8 M noscapine (3σ). The relative standard deviation of 2.0x10 -6 M noscapine was 1.0% (n=10). The proposed method was successfully applied for the flow injection determination of noscapine in cough and Tonin syrup samples. The results of real sample analyses show good recovery percentages (97.3-102.4%). The minimum sampling rate was 100 samples per hour
RAXBOD- INVISCID TRANSONIC FLOW OVER AXISYMMETRIC BODIES

Science.gov (United States)

Keller, J. D.

1994-01-01

The problem of axisymmetric transonic flow is of interest not only because of the practical application to missile and launch vehicle aerodynamics, but also because of its relation to fully three-dimensional flow in terms of the area rule. The RAXBOD computer program was developed for the analysis of steady, inviscid, irrotational, transonic flow over axisymmetric bodies in free air. RAXBOD uses a finite-difference relaxation method to numerically solve the exact formulation of the disturbance velocity potential with exact surface boundary conditions. Agreement with available experimental results has been good in cases where viscous effects and wind-tunnel wall interference are not important. The governing second-order partial differential equation describing the flow potential is replaced by a system of finite difference equations, including Jameson's "rotated" difference scheme at supersonic points. A stretching is applied to both the normal and tangential coordinates such that the infinite physical space is mapped onto a finite computational space. The boundary condition at infinity can be applied directly and there is no need for an asymptotic far-field solution. The system of finite difference equations is solved by a column relaxation method. In order to obtain both rapid convergence and any desired resolution, the relaxation is performed iteratively on successively refined grids. Input to RAXBOD consists of a description of the body geometry, the free stream conditions, and the desired resolution control parameters. Output from RAXBOD includes computed geometric parameters in the normal and tangential directions, iteration history information, drag coefficients, flow field data in the computational plane, and coordinates of the sonic line. This program is written in FORTRAN IV for batch execution and has been implemented on a CDC 6600 computer with an overlayed central memory requirement of approximately 40K (octal) of 60 bit words. Optional plotted output
Large Object Irradiation Facility In The Tangential Channel Of The JSI TRIGA Reactor

CERN Document Server

Radulovic, Vladimir; Kaiba, Tanja; Kavsek, Darko; Cindro, Vladimir; Mikuz, Marko; Snoj, Luka

2017-01-01

This paper presents the design and installation of a new irradiation device in the Tangential Channel of the JSI TRIGA reactor in Ljubljana, Slovenia. The purpose of the device is to enable on-line irradiation testing of electronic components considerably larger in size (of lateral dimensions of at least 12 cm) than currently possible in the irradiation channels located in the reactor core, in a relatively high neutron flux (exceeding 10^12 n cm^-2 s^-1) and to provide adequate neutron and gamma radiation shielding.
Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system.

Science.gov (United States)

Jakmunee, Jaroon; Junsomboon, Jaroon

2009-09-15

A new extraction procedure based on an off-line extraction column was proposed for extracting of available phosphorus from soils. The column was fabricated from a plastic syringe fitted at the bottom with a cotton wool and a piece of filter paper to support a soil sample. An aliquot (50 mL) of extracting solution (0.05 M HCl+0.0125 M H(2)SO(4)) was used to extract the sample under gravity flow and the eluate was collected in a polyethylene bottle. The extract was then analyzed for phosphorus contents by a simple flow injection amperometric system, employing a set of three-way solenoid valves as an injection valve. The method is based on the electrochemical reduction of 12-molybdophosphate which is produced on-line by the reaction of orthophosphate with acidic molybdate and the electrical current produced was directly proportional to the concentration of phosphate in range of 0.1-10.0 mg L(-1) PO(4)-P, with a detection limit of 0.02 mg L(-1). Relative standard for 11 replicate injections of 5 mg L(-1) PO(4)-P was 0.5%. A sample through put of 35 h(-1) was achieved, with consumption of 14 mg KCl, 10mg ammonium molybdate and 0.05 mL H(2)SO(4) per analysis. The detection system does not suffer from the interferences that are encountered in the photometric method such as colored substances, colloids, metal ions, silicate and refractive index effect (Schlieren effect). The results obtained by the column extraction procedure were well correlated with those obtained by the steady-state extraction procedure, but showed slightly higher extraction efficiency.
Individualized Selection of Beam Angles and Treatment Isocenter in Tangential Breast Intensity Modulated Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Penninkhof, Joan, E-mail: j.penninkhof@erasmusmc.nl [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands); Spadola, Sara [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands); Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, Bologna (Italy); Breedveld, Sebastiaan; Baaijens, Margreet [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands); Lanconelli, Nico [Department of Physics and Astronomy, Alma Mater Studiorum, University of Bologna, Bologna (Italy); Heijmen, Ben [Department of Radiation Oncology, Erasmus M.C. Cancer Institute, Rotterdam (Netherlands)

2017-06-01

Purpose and Objective: Propose a novel method for individualized selection of beam angles and treatment isocenter in tangential breast intensity modulated radiation therapy (IMRT). Methods and Materials: For each patient, beam and isocenter selection starts with the fully automatic generation of a large database of IMRT plans (up to 847 in this study); each of these plans belongs to a unique combination of isocenter position, lateral beam angle, and medial beam angle. The imposed hard planning constraint on patient maximum dose may result in plans with unacceptable target dose delivery. Such plans are excluded from further analyses. Owing to differences in beam setup, database plans differ in mean doses to organs at risk (OARs). These mean doses are used to construct 2-dimensional graphs, showing relationships between: (1) contralateral breast dose and ipsilateral lung dose; and (2) contralateral breast dose and heart dose (analyzed only for left-sided). The graphs can be used for selection of the isocenter and beam angles with the optimal, patient-specific tradeoffs between the mean OAR doses. For 30 previously treated patients (15 left-sided and 15 right-sided tumors), graphs were generated considering only the clinically applied isocenter with 121 tangential beam angle pairs. For 20 of the 30 patients, 6 alternative isocenters were also investigated. Results: Computation time for automatic generation of 121 IMRT plans took on average 30 minutes. The generated graphs demonstrated large variations in tradeoffs between conflicting OAR objectives, depending on beam angles and patient anatomy. For patients with isocenter optimization, 847 IMRT plans were considered. Adding isocenter position optimization next to beam angle optimization had a small impact on the final plan quality. Conclusion: A method is proposed for individualized selection of beam angles in tangential breast IMRT. This may be especially important for patients with cardiac risk factors or an

Injection of nano-particles in mitigating flow accelerated corrosion (FAC) damage in the secondary system of nuclear power plants (NPPs)

International Nuclear Information System (INIS)

Lim, Dong Seok; Ku, Hee Kwon; Cho, Jae Seon

2015-01-01

NPPs produces electric energy through phase transition of water. According to this, a piping, which is flow path, integrity is essential for safety functions. Erosion, FAC and fittings are corrosion failure mechanism by increasing service life. Especially, there are 10-kilometers of piping in secondary systems. It needs to estimate FAC and apply periodic management. Iron oxides produced by FAC cause power reduction and Loss Of Coolant Accident (LOCA) will be occurred through the continued piping wall thinning. In this study, corrosion rate of pipe materials with carbon steel(SA106.Gr.B) and low-alloy steel (SA335.P22) was evaluated for pipe configuration and dissolved oxygen concentration on 150 °C, pH 9.5∼10.0 and flow velocity of 5m/s. Temperature of 150°C is well known that causes high FAC rate and pH consider a NPPs in-service condition. Further corrosion rate test was performed to develop FAC reduction technology through Pt-nanoparticle injection. In this study, corrosion rate is evaluated by weight depletion method. The results of material impact assessment show that corrosion rate of carbon steel is more higher than that of low-alloy steel because of Cr content. And also, the results of pipe configuration test show that case with 90° elbow had maximum wall thinning than with 180° horizontal pipe. The dissolved oxygen concentration test shows that low oxygen condition, ≤5 ppb, had high corrosion rate compared to normal condition and the corrosion rate decreased 50% at Pt-nanoparticle injection test on maximum corrosion rate condition compared to maximum wall thinning condition without Pt-nanoparticle injection. In this study, samples provided by each test case had analyzed through SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy). Behavior evaluation for oxide film was performed and Electrochemical corrosion potential (ECP) was measured for electrochemistry evaluation. To apply Pt-nanoparticle injection technology on nuclear
Tangential boundary values of Laplace transforms. Applications to Muntz-Szasz type approximation

Energy Technology Data Exchange (ETDEWEB)

Sedletskii, A M [M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2003-02-28

We consider the Laplace transforms (LT) of functions in L{sup q}(R{sub +}), 1tangential boundary values almost everywhere on the imaginary axis, and the structure of the corresponding neighbourhoods depends on the weight only. This result is applied to distinguish a wide class of weighted L{sup p} spaces on the half-line such that the Szasz condition is not necessary for the completeness of the system exp(-{lambda}{sub n}t) in these spaces.
Sibutramine selective electrodes for batch and flow injection determinations in pharmaceutical preparations.

Science.gov (United States)

Zayed, S I M; Issa, Y M

2010-01-01

The construction and electrochemical response characteristics of two new polyvinyl chloride (PVC) membrane sensors for the determination of sibutramine hydrochloride were described. The sensors are based on the ion association complexes of sibutramine with sodium tetraphenylborate (NaTPB) or phosphotungstic acid (PTA) using dibutyl phthalate as plasticizing solvent. The sensors display a fast, stable response over the concentration range 3.84 x 10(-5)-1.00 x 10(-2) M sibutramine hydrochloride monohydrate (SibuCl), with cationic slopes of 57.7 +/- 0.57 and 59.7 +/- 1.79 mV concentration decade(-1) and detection limits of 8.91 x 10(-6) and 1.47 x 10(-5) M in case of sibutramine-tetraphenylborate (Sibu-TPB) and sibutramine-phosphotungstate ((Sibu)(3)-PT), respectively. The proposed sensors have been successfully applied for the determination of sibutramine hydrochloride in Regitrim capsules in batch and flow injection (FI) conditions.
A similar solution for an unsteady free convection flow past an impulsively started vertical plate with mass transfer and suction or injection

International Nuclear Information System (INIS)

Sattar, M.A.

1990-12-01

A similar solution for the flow past a vertical plate started impulsively in its own plane in a viscous incompressible fluid is presented on taking into account the effects of variable suction and/or injection and mass transfer. To solve the momentum, energy and concentration equations, a time dependent length scale is introduced, which leads to the driving parameters γ(=G r /R σ 2 ) and γ*(=G r */R σ 2 ), where G r and G r * are respectively the Grashof and modified Grashof numbers while R σ is the Reynolds number. The resulting locally similar momentum equation is then solved by the method of superposition. The effects of the parameters and that of suction/injection on the flow and on the wall shear-stress of the plate are shown graphically for different values of Schmidt number and transpiration parameter. (author). 24 refs, 11 figs
Flow velocity effect on the corrosion/erosion in water injection systems; Efecto de la velocidad de flujo en la corrosion/erosion en sistemas de inyeccion de agua

Energy Technology Data Exchange (ETDEWEB)

Jimenez, C.; Mendez, J. [PDVSA Exploracion y reduccion, Departamento de Ingenieria de Instalaciones, Torres Petroleras EX-MRV, Torre Lama, Piso No. 6, Zulia, Apartado 4013, Venezuela (Venezuela)

1998-12-31

The main causes of fails at water injection lines on the secondary petroleum recovery systems are related with corrosion/erosion problems which are influenced by the flow velocity, the presence of dissolved oxygen, solids in the medium and the microorganisms proliferation. So too, this corrosion process promotes the suspended solids generation which affects the water quality injected, causing wells tamponage and loss of injectivity, with the consequent decrease in the crude production. This situation has been impacted in meaning order at the production processes of an exploration enterprise which utilizes the Maracaibo lake as water resource for their injection by pattern projects. Stating that, it was developed a study for determining in experimental order the effect of flow velocity on the corrosion/erosion process joined to the presence of dissolved oxygen which allows to determine the optimum range of the said working velocity for the water injection systems. This range is defined by critical velocities of bio layers deposition and erosion. They were realized simulation pilot tests of the corrosion standard variables, concentration of dissolved oxygen and fluid velocity in the injection systems with filtered and non filtered water. For the development of these tests it was constructed a device which allows to install and expose cylindrical manometers of carbon steel according to predetermined conditions which was obtained the necessary information to make correlations the results of these variables. Additionally, they were determined the mathematical models that adjusts to dynamical behavior of the corrosion/erosion process, finding the optimum range of the flow velocity for the control of this process, being necessary to utilize the following techniques: Scanning Electron Microscopy (SEM), X-ray dispersion analysis (EDX) for encourage the surface studies. They were effected morphological analysis of the surfaces studies and the values were determined of
Flow injection analysis-flame atomic absorption spectrometry system for indirect determination of sulfite after on-line reduction of solid-phase manganese (IV) dioxide reactor.

Science.gov (United States)

Zare-Dorabei, Rouholah; Boroun, Shokoufeh; Noroozifar, Meissam

2018-02-01

A new and simple flow injection method followed by atomic absorption spectrometry was developed for indirect determination of sulfite. The proposed method is based on the oxidation of sulfite to sulphate ion using solid-phase manganese dioxide (30% W/W suspended on silica gel beads) reactor. MnO 2 will be reduced to Mn(II) by sample injection in to the column under acidic carrier stream of HNO 3 (pH 2) with flow rate of 3.5mLmin -1 at room temperature. Absorption measurement of Mn(II) which is proportional to the concentration of sulfite in the sample was carried out by atomic absorption spectrometry. The calibration curve was linear up to 25mgL -1 with a detection limit (DL) of 0.08mgL -1 for 400µL injection sample volume. The presented method is efficient toward sulfite determination in sugar and water samples with a relative standard deviation (RSD) less than 1.2% and a sampling rate of about 60h -1 . Copyright © 2017 Elsevier B.V. All rights reserved.
A tangentially viewing VUV TV system for the DIII-D divertor

International Nuclear Information System (INIS)

Nilson, D.G.; Ellis, R.; Fenstermacher, M.E.; Brewis, G.; Jalufka, N.

1998-07-01

A video camera system capable of imaging VUV emission in the 120--160 nm wavelength range, from the entire divertor region in the DIII-D tokamak, was designed. The new system has a tangential view of the divertor similar to an existing tangential camera system which has produced two dimensional maps of visible line emission (400--800 nm) from deuterium and carbon in the divertor region. However, the overwhelming fraction of the power radiated by these elements is emitted by resonance transitions in the ultraviolet, namely the C IV line at 155.0 nm and Ly-α line at 121.6 nm. To image the ultraviolet light with an angular view including the inner wall and outer bias ring in DIII-D, a 6-element optical system (f/8.9) was designed using a combination of reflective and refractive optics. This system will provide a spatial resolution of 1.2 cm in the object plane. An intermediate UV image formed in a secondary vacuum is converted to the visible by means of a phosphor plate and detected with a conventional CID camera (30 ms framing rate). A single MgF 2 lens serves as the vacuum interface between the primary and secondary vacuums; a second lens must be inserted in the secondary vacuum to correct the focus at 155 nm. Using the same tomographic inversion method employed for the visible TV, they reconstruct the poloidal distribution of the UV divertor light. The grain size of the phosphor plate and the optical system aberrations limit the best focus spot size to 60 microm at the CID plane. The optical system is designed to withstand 350 C vessel bakeout, 2 T magnetic fields, and disruption-induced accelerations of the vessel
LES of stratified-wavy flows using novel near-interface treatment

Science.gov (United States)

Karnik, Aditya; Kahouadji, Lyes; Chergui, Jalel; Juric, Damir; Shin, Seungwon; Matar, Omar K.

2017-11-01

The pressure drop in horizontal stratified wavy flows is influenced by interfacial shear stress. The near-interface behavior of the lighter phase is akin to that near a moving wall. We employ a front-tracking code, Blue, to simulate and capture the near-interface behaviour of both phases. Blue uses a modified Smagorinsky LES model incorporating a novel near-interface treatment for the sub-grid viscosity, which is influenced by damping due to the wall-like interface, and enhancement of the turbulent kinetic energy (TKE) due to the interfacial waves. Simulations are carried out for both air-water and oil-water stratified configurations to demonstrate the applicability of the present method. The mean velocities and tangential Reynolds stresses are compared with experiments for both configurations. At the higher Re, the waves penetrate well into the buffer region of the boundary layer above the interface thus altering its dynamics. Previous attempts to capture the secondary structures associated with such flows using RANS or standard LES methodologies have been unsuccessful. The ability of the present method to reproduce these structures is due to the correct estimation of the near-interface TKE governing energy transfer from the normal to tangential directions. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM).
Analysis of large break loss of coolant accident with simultaneous injection into cold leg and hot leg

International Nuclear Information System (INIS)

Luo Bangqi

1997-01-01

When a large break loss of coolant accident occurs, the most part of the safety injection water injected into the cold leg by the safety injection system will flow through the channel between the pressure vessel and the barrel out of the break into the containment, only a little part of the safety injection water can flow into the reactor core. If the safety injection can inject into both the cold leg and the hot leg simultaneously, the safety injection water injected from the cold leg will flow into the core more easily, because the safety injection water injected from the hot leg will carry out more heat from the upper plenum and the core, so the upper plenum and the core is depressed. In addition, a small part of the safety injection water injected from the hot leg will flow down in the core after impinging the guide tubes in the upper plenum, so the core will get more safety injection water than only cold leg injection, and the core will be much safer
Radial force distribution changes associated with tangential force production in cylindrical grasping, and the importance of anatomical registration.

Science.gov (United States)

Pataky, Todd C; Slota, Gregory P; Latash, Mark L; Zatsiorsky, Vladimir M

2012-01-10

Radial force (F(r)) distributions describe grip force coordination about a cylindrical object. Recent studies have employed only explicit F(r) tasks, and have not normalized for anatomical variance when considering F(r) distributions. The goals of the present study were (i) to explore F(r) during tangential force production tasks, and (ii) to examine the extent to which anatomical registration (i.e. spatial normalization of anatomically analogous structures) could improve signal detectability in F(r) data. Twelve subjects grasped a vertically oriented cylindrical handle (diameter=6 cm) and matched target upward tangential forces of 10, 20, and 30 N. F(r) data were measured using a flexible pressure mat with an angular resolution of 4.8°, and were registered using piecewise-linear interpolation between five manually identified points-of-interest. Results indicate that F(r) was primarily limited to three contact regions: the distal thumb, the distal fingers, and the fingers' metatacarpal heads, and that, while increases in tangential force caused significant increases in F(r) for these regions, they did not significantly affect the F(r) distribution across the hand. Registration was found to substantially reduce between-subject variability, as indicated by both accentuated F(r) trends, and amplification of the test statistic. These results imply that, while subjects focus F(r) primarily on three anatomical regions during cylindrical grasp, inter-subject anatomical differences introduce a variability that, if not corrected for via registration, may compromise one's ability to draw anatomically relevant conclusions from grasping force data. Copyright © 2011 Elsevier Ltd. All rights reserved.
Optimal Power Flow Control by Rotary Power Flow Controller

Directory of Open Access Journals (Sweden)

KAZEMI, A.

2011-05-01

Full Text Available This paper presents a new power flow model for rotary power flow controller (RPFC. RPFC injects a series voltage into the transmission line and provides series compensation and phase shifting simultaneously. Therefore, it is able to control the transmission line impedance and the active power flow through it. An RPFC is composed mainly of two rotary phase shifting transformers (RPST and two conventional (series and shunt transformers. Structurally, an RPST consists of two windings (stator and rotor windings. The rotor windings of the two RPSTs are connected in parallel and their stator windings are in series. The injected voltage is proportional to the vector sum of the stator voltages and so its amplitude and angle are affected by the rotor position of the two RPSTs. This paper, describes the steady state operation and single-phase equivalent circuit of the RPFC. Also in this paper, a new power flow model, based on power injection model of flexible ac transmission system (FACTS controllers, suitable for the power flow analysis is introduced. Proposed model is used to solve optimal power flow (OPF problem in IEEE standard test systems incorporating RPFC and the optimal settings and location of the RPFC is determined.
Photometric estimation of plutonium in product solutions and acid waste solutions using flow injection analysis technique

International Nuclear Information System (INIS)

Dhas, A.J.A.; Dharmapurikar, G.R.; Kumaraguru, K.; Vijayan, K.; Kapoor, S.C.; Ramanujam, A.

1995-01-01

Flow injection analysis technique is employed for the measurement of plutonium concentrations in product nitrate solutions by measuring the absorbance of Pu(III) at 565 nm and of Pu(IV) at 470 nm, using a Metrohm 662 photometer, with a pyrex glass tube of 2 nm (ID) inserted in the light path of the detector serving as a flow cell. The photometer detector never comes in contact with radioactive solution. In the case of acid waste solutions Pu is first purified by extraction chromatography with 2-ethyl hexyl hydrogen 2 ethyl hexyl phosphonate (KSM 17)- chromosorb and the Pu in the eluate in complexed with Arsenazo III followed by the measured of absorbance at 665 nm. Absorbance of reference solutions in the desired concentration ranges are measured to calibrate the system. The results obtained agree with the reference values within ±2.0%. (author). 3 refs., 1 tab
Large scale gas injection test (Lasgit): Results from two gas injection tests

International Nuclear Information System (INIS)

Cuss, R. J.; Harrington, J. F.; Noy, D. J.; Wikman, A.; Sellin, P.

2011-01-01

This paper describes the initial results from a large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory (Sweden)). Lasgit is a full-scale field-scale experiment based on the Swedish KBS-3V repository concept, examining the processes controlling gas and water flow in compact buffer bentonite. The first 2 years of the test focused on the artificial hydration of the bentonite buffer. This was followed by a programme of hydraulic and gas injection tests which ran from day 843 to 1110. A further period of artificial hydration occurred from day 1110 to 1385, followed by a more complex programme of gas injection testing which remains on going (day 1385+). After 2 years of hydration, hydraulic conductivity and specific storage values in the lower filter array were found to range from 9 x 10 -14 to 1.6 x 10 -13 m/s and 5.5 x 10 -5 to 4.4 x 10 -4 m -1 respectively, with the injection filter FL903 yielding values of 7.5 x 10 -14 m/s and 2.5 x 10 -5 m -1 . A second set of hydraulic measurements were performed over 1 year and a half later yielding similar values, in the range 7.8 x 10 -14 m/s and 1.3 x 10 -13 m/s. The hydraulic conductivity of FL903 had reduced slightly to 5.3 x 10 -14 m/s while specific storage had increased to 4.0 x 10 -5 m -1 . Both datasets agree with laboratory values performed on small-scale saturated samples. Two sets of gas injection tests were performed over a 3 year period. During the course of testing, gas entry pressure was found to increase from around 650 kPa to approximately 1.3 MPa, indicative of the maturation of the clay. The sequential reduction in volumetric flow rate and lack of correlation between the rate of gas inflow and the gas pressure gradient observed during constant pressure steps prior to major gas entry, is suggestive of a reduction in gas permeability of the buffer and indicates only limited quantities of gas can be injected into the clay without interacting with the continuum stress field. Major gas
Magnus effect on laminar flow around a rotating cylinder

International Nuclear Information System (INIS)

Amarante, J.C.A.

1989-01-01

The laminar flow around a rotating cylinder is studied, through the numerical solution of the full Navier-Stokes equations, for Reynolds number, based on cylinder radius, varying between 0.5 and 25 and for non-dimensional tangential velocities of the body surface between zero and 8. The Taylor and Hughes method is employed in the theoretical investigation. The Magnus lift coefficient and the drag coefficient are obtained and the presure and vorticity distribution are calculated. (author)
Study on improvement of the lifetime of a field-reversed configuration by tangential neutron beam injection

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kondoh, Yoshiomi; Hirano, Yoichi; Asai, Tomohiko; Takahashi, Tsutomu; Mizuguchi, Naoki; Tomita, Yukihiro

2006-01-01

The numerical analysis of neutron beam injection (NBI) is carried out to keep the stationary conditions of the field-reversed configuration (FRC) plasma. The ionization process of neutron beam was reproduced by the Monte Carlo method. A confinement of 15 keV beam ion was investigated using the sharp of stormer region obtained by the position and velocity at a moment of ionization. The relation between the external magnetic field B ex [T] and radius of machine r w [m] was shown by B ex = 0.1 r w -3/4 . The power imparted to plasma was estimated by beam ion orbital calculation. The confinement coefficient of beam ion was lost by re-charge-exchange reaction with deuterium; this fact was discovered at first. In order to keep the configuration of plasma under the conditions of 0.2 T of the external magnetic field, 0.4 m of radius, and 100 eV ion temperature, about 17 MW/m NBI power is needed. (S.Y.)
Two-dimensional analysis of two-phase reacting flow in a firing direct-injection diesel engine

Science.gov (United States)

Nguyen, H. Lee

1989-01-01

The flow field, spray penetration, and combustion in two-stroke diesel engines are described. Fuel injection begins at 345 degrees after top dead center (ATDC) and n-dodecane is used as the liquid fuel. Arrhenius kinetics is used to calculate the reaction rate term in the quasi-global combustion model. When the temperature, fuel, and oxygen mass fraction are within suitable flammability limits, combustion begins spontaneously. No spark is necessary to ignite a localized high temperature region. Compression is sufficient to increase the gaseous phase temperature to a point where spontaneous chemical reactions occur. Results are described for a swirl angle of 22.5 degrees.
Phenylboronic acid immunoaffinity reactor coupled with flow injection chemiluminescence for determination of {alpha}-fetoprotein

Energy Technology Data Exchange (ETDEWEB)

Wu Yafeng [Jiangsu Provincial Key Lab of Biomaterials and Biodevices, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096 (China); Zhuang Yafeng [Department of Chemistry, Changzhou Institute of Technology, Changzhou 213022 (China); Liu Songqin [Jiangsu Provincial Key Lab of Biomaterials and Biodevices, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096 (China)], E-mail: liusq@seu.edu.cn; He Lin [Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204 (United States)

2008-12-23

A reusable and sensitive immunoassay based on phenylboronic acid immunoaffinity reactor in combination with flow injection chemiluminescence (CL) for determination of glycoprotein was described. The reactor was fabricated by immobilizing 3-aminophenylboronic acid (APBA) on glass microbeads with {gamma}-glycidoxypropyltrimethoxysilane (GPMS) as linkage. The {alpha}-fetoprotein (AFP) could be easily immobilized on the APBA coated beads through sugar-boronic interaction. After an off-line incubation, the mixture of the analyte AFP with horseradish peroxidase-labeled AFP antibody (HRP-anti-AFP) was injected into the reactor. This led the trapping of free HRP-anti-AFP by the surface coated AFP on glass beads. The trapped HRP-anti-AFP was detected by chemiluminescence due to its sensitizing effect on the reaction of luminol and hydrogen peroxide. Under optimal conditions, the chemiluminescent signal was proportional to AFP concentration in the range of 10-100 ng mL{sup -1}. The whole assay process including regeneration of the reactor could be completed within 31 min. The proposed system showed acceptable detection and fabrication reproducibility, and the results obtained with the present method were in acceptable agreement with those from parallel single-analyte test of practical clinical sera. The described method enabled a low-cost, time saving and was potential to detect the serum AFP level in clinical diagnosis.
Use of a tangential filtration unit for processing liquid waste from nuclear laundries

International Nuclear Information System (INIS)

Augustin, X.; Buzonniere, A. de; Barnier, H.

1993-01-01

Nuclear laundries produce large quantities of weakly contaminated effluents charged with insoluble and soluble products. In collaboration with CEA, TECHNICATOME has developed an ultrafiltration process for liquid waste from nuclear laundries, associated with prior in-solubilization of the radiochemical activity. This process 'seeded ultrafiltration' is based on the use of decloggable mineral filter media and combines very high separation efficiency with long membrane life. The efficiency of the tangential filtration unit which has been processing effluents from the Cadarache Nuclear Research Center (CEA-France) nuclear laundry since mid-1988, has been confirmed on several sites
The fall of the Northern Unicorn: Tangential motions in the Galactic Anti-centre with SDSS and Gaia

OpenAIRE

de Boer, T. J. L.; Belokurov, V.; Koposov, S. E.

2017-01-01

We present the first detailed study of the behaviour of the stellar proper motion across the entire Galactic Anti-centre area visible in the Sloan Digital Sky Survey data. We use recalibrated SDSS astrometry in combination with positions from {\\it Gaia} DR1 to provide tangential motion measurements with a systematic uncertainty $
Hydrogen/oxygen injection stopping method for nuclear power plant and emergent hydrogen/oxygen injection device

International Nuclear Information System (INIS)

Ishida, Ryoichi; Ota, Masamoto; Takagi, Jun-ichi; Hirose, Yuki

1998-01-01

The present invention provides a device for suppressing increase of electroconductivity of reactor water during operation of a BWR type reactor, upon occurrence of reactor scram of the plant or upon stopping of hydrogen/oxygen injection due to emergent stoppage of an injection device so as not to deteriorate the integrity of a gas waste processing system upon occurrence of scram. Namely, when injection of hydrogen/oxygen is stopped during plant operation, the injection amount of hydrogen is reduced gradually. Subsequently, injection of hydrogen is stopped. With such procedures, the increase of electroconductivity of reactor water can be suppressed upon stoppage of hydrogen injection. When injection of hydrogen/oxygen is stopped upon shut down of the plant, the amount of hydrogen injection is changed depending on the change of the feedwater flow rate, and then the plant is shut down while keeping hydrogen concentration of feedwater to a predetermined value. With such procedures, increase of the reactor water electroconductivity can be suppressed upon stoppage of hydrogen injection. Upon emergent stoppage of the hydrogen/oxygen injection device, an emergent hydrogen/oxygen injection device is actuated to continue the injection of hydrogen/oxygen. With such procedures, elevation of reactor water electroconductivity can be suppressed. (I.S.)

Seasonal Variability in Regional Ice Flow Due to Meltwater Injection Into the Shear Margins of Jakobshavn Isbræ

Science.gov (United States)

Cavanagh, J. P.; Lampkin, D. J.; Moon, T.

2017-12-01

The impact of meltwater injection into the shear margins of Jakobshavn Isbræ via drainage from water-filled crevasses on ice flow is examined. We use Landsat-8 Operational Land Imager panchromatic, high-resolution imagery to monitor the spatiotemporal variability of seven water-filled crevasse ponds during the summers of 2013 to 2015. The timing of drainage from water-filled crevasses coincides with an increase of 2 to 20% in measured ice velocity beyond Jakobshavn Isbræ shear margins, which we define as extramarginal ice velocity. Some water-filled crevasse groups demonstrate multiple drainage events within a single melt season. Numerical simulations show that hydrologic shear weakening due to water-filled crevasse drainage can accelerate extramarginal flow by as much as 35% within 10 km of the margins and enhance mass flux through the shear margins by 12%. This work demonstrates a novel mechanism through which surface melt can influence regional ice flow.
Performance and emission studies on port injection of hydrogen with varied flow rates with Diesel as an ignition source

International Nuclear Information System (INIS)

Saravanan, N.; Nagarajan, G.

2010-01-01

Automobiles are one of the major sources of air pollution in the environment. In addition CO 2 emission, a product of complete combustion also has become a serious issue due to global warming effect. Hence the search for cleaner alternative fuels has become mandatory. Hydrogen is expected to be one of the most important fuels in the near future for solving the problems of air pollution and greenhouse gas problems (carbon dioxide), thereby protecting the environment. Hence in the present work, an experimental investigation has been carried out using hydrogen in the dual fuel mode in a Diesel engine system. In the study, a Diesel engine was converted into a dual fuel engine and hydrogen fuel was injected into the intake port while Diesel was injected directly inside the combustion chamber during the compression stroke. Diesel injected inside the combustion chamber will undergo combustion first which in-turn would ignite the hydrogen that will also assist the Diesel combustion. Using electronic control unit (ECU), the injection timings and injection durations were varied for hydrogen injection while for Diesel the injection timing was 23 o crank angle (CA) before injection top dead centre (BITDC). Based on the performance, combustion and emission characteristics, the optimized injection timing was found to be 5 o CA before gas exchange top dead centre (BGTDC) with injection duration of 30 o CA for hydrogen Diesel dual fuel operation. The optimum hydrogen flow rate was found to be 7.5 lpm. Results indicate that the brake thermal efficiency in hydrogen Diesel dual fuel operation increases by 15% compared to Diesel fuel at 75% load. The NO X emissions were higher by 1-2% in dual fuel operation at full load compared to Diesel. Smoke emissions are lower in the entire load spectra due to the absence of carbon in hydrogen fuel. The carbon monoxide (CO), carbon dioxide (CO 2 ) emissions were lesser in hydrogen Diesel dual fuel operation compared to Diesel. The use of hydrogen
Performance and emission studies on port injection of hydrogen with varied flow rates with Diesel as an ignition source

Energy Technology Data Exchange (ETDEWEB)

Saravanan, N. [ERC Engines, Tata Motors, Pimpri, Pune (India); Nagarajan, G. [Internal Combustion Engineering Division, Department of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai (India)

2010-07-15

Automobiles are one of the major sources of air pollution in the environment. In addition CO{sub 2} emission, a product of complete combustion also has become a serious issue due to global warming effect. Hence the search for cleaner alternative fuels has become mandatory. Hydrogen is expected to be one of the most important fuels in the near future for solving the problems of air pollution and greenhouse gas problems (carbon dioxide), thereby protecting the environment. Hence in the present work, an experimental investigation has been carried out using hydrogen in the dual fuel mode in a Diesel engine system. In the study, a Diesel engine was converted into a dual fuel engine and hydrogen fuel was injected into the intake port while Diesel was injected directly inside the combustion chamber during the compression stroke. Diesel injected inside the combustion chamber will undergo combustion first which in-turn would ignite the hydrogen that will also assist the Diesel combustion. Using electronic control unit (ECU), the injection timings and injection durations were varied for hydrogen injection while for Diesel the injection timing was 23 crank angle (CA) before injection top dead centre (BITDC). Based on the performance, combustion and emission characteristics, the optimized injection timing was found to be 5 CA before gas exchange top dead centre (BGTDC) with injection duration of 30 CA for hydrogen Diesel dual fuel operation. The optimum hydrogen flow rate was found to be 7.5 lpm. Results indicate that the brake thermal efficiency in hydrogen Diesel dual fuel operation increases by 15% compared to Diesel fuel at 75% load. The NO{sub X} emissions were higher by 1-2% in dual fuel operation at full load compared to Diesel. Smoke emissions are lower in the entire load spectra due to the absence of carbon in hydrogen fuel. The carbon monoxide (CO), carbon dioxide (CO{sub 2}) emissions were lesser in hydrogen Diesel dual fuel operation compared to Diesel. The use of
Spectrophotometric determination of phosphorus in iron alloys employing a flow injection system

Directory of Open Access Journals (Sweden)

Gervasio Ana P. G.

2001-01-01

Full Text Available A flow-injection procedure for spectrophotometric determination of phosphorus in electrolytic iron and iron alloys is proposed. The method is based on the ammonium molybdate reaction followed by stannous chloride reduction in acidic medium. In order to circumvent the severe interference caused by the major constituents such as Fe(III and Cr(III, a mini-column packed with AG50W-X8 resin was coupled to the manifold. A sample throughput of 40 determinations per hour, a dynamical range from P 0.25 to 6.00 mg L-1, a reagent consumption of 25 mg ammonium molybdate and 2 mg stannous chloride per determination, and a relative standard deviation < 1% (n = 10 for a typical sample with 2.20 mg L-1 P were achieved. Three different types of samples were used to evaluate system performance. Accuracy was assessed by comparing the results with certified values and no significant difference at 95 % confidence level was observed.
Fast-responsive hydrogel as an injectable pump for rapid on-demand fluidic flow control.

Science.gov (United States)

Luo, Rongcong; Dinh, Ngoc-Duy; Chen, Chia-Hung

2017-05-01

Chemically synthesized functional hydrogels have been recognized as optimized soft pumps for on-demand fluidic regulation in micro-systems. However, the challenges regarding the slow responses of hydrogels have very much limited their application in effective fluidic flow control. In this study, a heterobifunctional crosslinker (4-hydroxybutyl acrylate)-enabled two-step hydrothermal phase separation process for preparing a highly porous hydrogel with fast response dynamics was investigated for the fabrication of novel microfluidic functional units, such as injectable valves and pumps. The cylinder-shaped hydrogel, with a diameter of 9 cm and a height of 2.5 cm at 25 °C, achieved a size reduction of approximately 70% in less than 30 s after the hydrogels were heated at 40 °C. By incorporating polypyrrole nanoparticles as photothermal transducers, a photo-responsive composite hydrogel was approached and exhibited a remotely triggerable fluidic regulation and pumping ability to generate significant flows, showing on-demand water-in-oil droplet generation by laser switching, whereby the droplet size could be tuned by adjusting the laser intensity and irradiation period with programmable manipulation.
[Research on optimization of mathematical model of flow injection-hydride generation-atomic fluorescence spectrometry].

Science.gov (United States)

Cui, Jian; Zhao, Xue-Hong; Wang, Yan; Xiao, Ya-Bing; Jiang, Xue-Hui; Dai, Li

2014-01-01

Flow injection-hydride generation-atomic fluorescence spectrometry was a widely used method in the industries of health, environmental, geological and metallurgical fields for the merit of high sensitivity, wide measurement range and fast analytical speed. However, optimization of this method was too difficult as there exist so many parameters affecting the sensitivity and broadening. Generally, the optimal conditions were sought through several experiments. The present paper proposed a mathematical model between the parameters and sensitivity/broadening coefficients using the law of conservation of mass according to the characteristics of hydride chemical reaction and the composition of the system, which was proved to be accurate as comparing the theoretical simulation and experimental results through the test of arsanilic acid standard solution. Finally, this paper has put a relation map between the parameters and sensitivity/broadening coefficients, and summarized that GLS volume, carrier solution flow rate and sample loop volume were the most factors affecting sensitivity and broadening coefficients. Optimizing these three factors with this relation map, the relative sensitivity was advanced by 2.9 times and relative broadening was reduced by 0.76 times. This model can provide a theoretical guidance for the optimization of the experimental conditions.
Tangential vitreous traction: a possible mechanism of development of cystoid macular edema in retinitis pigmentosa

Directory of Open Access Journals (Sweden)

Mikiko Takezawa

2011-02-01

Full Text Available Mikiko Takezawa, Soichi Tetsuka, Akihiro KakehashiDepartment of Ophthalmology, Jichi Medical University, Saitama Medical Center, Saitama, Saitama, JapanAbstract: We report the possible mechanism of development of cystoid macular edema (CME in retinitis pigmentosa (RP in the case of a 68-year-old woman with RP and CME in the right eye and resolving CME in the left eye. Spectral domain optical coherence tomography showed CME and posterior vitreoschisis in the nasal quadrant of the fundus without a posterior vitreous detachment (PVD. This vitreous pathology suggested bilateral thickening and shrinkage of the posterior vitreous cortex. In the right eye, CME was evident with no vitreofoveal separation. However, in the left eye, minimal change was seen in the CME associated with a focal shallow PVD over the fovea. The best-corrected visual acuity (BCVA in the left eye increased to 0.3 from 0.15 7 years after the first visit. Tangential vitreous traction on the macula may have caused the CME in the right eye. The shallow PVD over the fovea might have released the tangential vitreous traction from the fovea, induced spontaneous resolution of the CME, and improved the BCVA in the left eye.Keywords: retinitis pigmentosa, cystoid macular edema, posterior vitreous detachment, posterior vitreoschisis, optical coherence tomography
Flow injection spectrophotometry using natural reagent from Morinda citrifolia root for determination of aluminium in tea.

Science.gov (United States)

Tontrong, Sopa; Khonyoung, Supada; Jakmunee, Jaroon

2012-05-01

A flow injection (FI) spectrophotometric method with using natural reagent extracted from Morinda citrifolia root has been developed for determination of aluminium. The extract contained anthraquinone compounds which could react with Al(3+) to form reddish complexes which had maximum absorption wavelength at 499.0nm. The extract could be used as a reagent in FI system without further purification to obtain pure compound. A sensitive method for determination of aluminium in concentration range of 0.1-1.0mgL(-1), with detection limit of 0.05mgL(-1) was achieved. Relative standard deviations of 1.2% and 1.7% were obtained for the determination of 0.1 and 0.6mgL(-1) Al(3+) (n=11). Sample throughput of 35h(-1) was achieved with the consumption of 3mL each of carrier and reagent solutions per injection. The developed method was successfully applied to tea samples, validated by the FAAS standard method. The method is simple, fast, economical and could be classified as a greener analytical method. Copyright © 2011 Elsevier Ltd. All rights reserved.
Method and apparatus for injecting fluid

Energy Technology Data Exchange (ETDEWEB)

Hyde, W E

1966-07-05

A method and apparatus are described for injecting grouting material into porous, fractured, unconsolidated, or other formations, whose cohesion is to be increased and/or whose permeability is to be decreased. A tool for injecting the fluid consists of a packer and valves through which the pressurized fluid may pass from the interior of the tool to the packer to expand it. Another valve allows pressure fluid to be vented so as to allow contraction of the packer. A third valve allows a flow of pressurized flow out of the tool and into the material when a predetermined pressure within the tool has been attained. (9 claims)
Flow structure of conical distributed multiple gas jets injected into a water chamber

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jiajun; Yu, Yonggang [Nanjing University of Science and Technology, Nanjing (China)

2017-04-15

Based on an underwater gun firing project, a mock bullet with several holes on the head was designed and experimented to observe the combustion gas injected into a cylindrical water chamber through this mock bullet. The combustion gas jets contain one vertical central jet and 4 to 8 slant lateral jets. A high speed camera system was used to record the expansion of gas jets in the experimental study. In numerical simulations, the Euler two-fluid model and volume of fluid method were adopted to describe the gas-liquid flow. The results show the backflow zone in lateral jet is the main factor influencing the gas-liquid turbulent mixing in downstream. On cross sections, the gas volume fraction increased with time but the growth rate decreased. With a change of nozzle structure, the gas fraction was more affected than the shock structure.
Construction and performance characterization of ion-selective electrodes for potentiometric determination of pseudoephedrine hydrochloride applying batch and flow injection analysis techniques.

Science.gov (United States)

Zayed, Sayed I M; Issa, Yousry M; Hussein, Ahmed

2006-01-01

New pseudoephedrine selective electrodes have been constructed of the conventional polymer membrane type by incorporation of pseudoephedrine-phosphotungstate (PE-PT) or pseudoephedrine-silicotungstate (PE-SiT) ion-associates in a poly vinyl chloride (PVC) membrane plasticized with dibutyl phthalate (DBP). The electrodes were fully characterized in terms of the membrane composition, temperature, and pH. The electrodes exhibited mean slopes of calibration graphs of 57.09 and 56.10 mV concentration decade(-1) of PECl at 25 degrees C for (PE-PT) and (PE-SiT) electrodes, respectively. The electrodes showed fast, stable, and near-Nernstian response over the concentration ranges 6.31 x 10(-6)-1.00 x 10(-2) and 5.00 x 10(-5)-1.00x10(-2) M in the case of PE-PT applying batch and flow injection (FI) analysis, respectively, and 1.00 x 10(-5)-1.00 x 10(-2) and 5.00 x 10(-5)-1.00x10(-2) M in the case of PE-SiT for batch and FI analysis system, respectively. Detection limit was 5.01x 10(-6) M for PE-PT electrode and 6.31x10(-6) M for PE-SiT electrode. The electrodes were successfully applied for the potentiometric determination of pseudoephedrine hydrochloride (PECl) in pharmaceutical preparations with mean recovery 101.13 +/- 0.85% and 100.77+0.79% in case of PE-PT applying batch and flow injection systems, respectively, and 100.75+0.85% and 100.79 +/- 0.77% in case of PE-SiT for batch and flow injection systems, respectively. The electrodes exhibited good selectivity for PECl with respect to a large number of inorganic cations, sugars and amino acids.
Analysis of interfraction and intrafraction variation during tangential breast irradiation with an electronic portal imaging device

International Nuclear Information System (INIS)

Smith, Ryan P.; Bloch, Peter; Harris, Eleanor E.; McDonough, James; Sarkar, Abhirup; Kassaee, Alireza; Avery, Steven; Solin, Lawrence J.

2005-01-01

Purpose: To evaluate the daily setup variation and the anatomic movement of the heart and lungs during breast irradiation with tangential photon beams, as measured with an electronic portal imaging device. Methods and materials: Analysis of 1,709 portal images determined changes in the radiation field during a treatment course in 8 patients. Values obtained for every image included central lung distance (CLD) and area of lung and heart within the irradiated field. The data from these measurements were used to evaluate variation from setup between treatment days and motion due to respiration and/or patient movement during treatment delivery. Results: The effect of respiratory motion and movement during treatment was minimal: the maximum range in CLD for any patient on any day was 0.25 cm. The variation caused by day-to-day setup variation was greater, with CLD values for patients ranging from 0.59 cm to 2.94 cm. Similar findings were found for heart and lung areas. Conclusions: There is very little change in CLD and corresponding lung and heart area during individual radiation treatment fractions in breast tangential fields, compared with a relatively greater amount of variation that occurs between days
A transit-time flow meter for measuring milliliter per minute liquid flow

DEFF Research Database (Denmark)

Yang, Canqian; Kymmel, Mogens; Søeberg, Henrik

1988-01-01

A transit-time flow meter, using periodic temperature fluctuations as tracers, has been developed for measuring liquid flow as small as 0.1 ml/min in microchannels. By injecting square waves of heat into the liquid flow upstream with a tiny resistance wire heater, periodic temperature fluctuation....... This flow meter will be used to measure and control the small liquid flow in microchannels in flow injection analysis. Review of Scientific Instruments is copyrighted by The American Institute of Physics....... are generated downstream. The fundamental frequency phase shift of the temperature signal with respect to the square wave is found to be a linear function of the reciprocal mean velocity of the fluid. The transit-time principle enables the flow meter to have high accuracy, better than 0.2%, and good linearity...
Biosensing of glucose in flow injection analysis system based on glucose oxidase-quantum dot modified pencil graphite electrode.

Science.gov (United States)

Sağlam, Özlem; Kızılkaya, Bayram; Uysal, Hüseyin; Dilgin, Yusuf

2016-01-15

A novel amperometric glucose biosensor was proposed in flow injection analysis (FIA) system using glucose oxidase (GOD) and Quantum dot (ZnS-CdS) modified Pencil Graphite Electrode (PGE). After ZnS-CdS film was electrochemically deposited onto PGE surface, GOD was immobilized on the surface of ZnS-CdS/PGE through crosslinking with chitosan (CT). A pair of well-defined reversible redox peak of GOD was observed at GOD/CT/ZnS-CdS/PGE based on enzyme electrode by direct electron transfer between the protein and electrode. Further, obtained GOD/CT/ZnS-CdS/PGE offers a disposable, low cost, selective and sensitive electrochemical biosensing of glucose in FIA system based on the decrease of the electrocatalytic response of the reduced form of GOD to dissolved oxygen. Under optimum conditions (flow rate, 1.3mL min(-1); transmission tubing length, 10cm; injection volume, 100μL; and constant applied potential, -500mV vs. Ag/AgCl), the proposed method displayed a linear response to glucose in the range of 0.01-1.0mM with detection limit of 3.0µM. The results obtained from this study would provide the basis for further development of the biosensing using PGE based FIA systems. Copyright © 2015 Elsevier B.V. All rights reserved.
Application of direct-injection detector integrated with the multi-pumping flow system to chemiluminescence determination of the total polyphenol index.

Science.gov (United States)

Nalewajko-Sieliwoniuk, Edyta; Iwanowicz, Magdalena; Kalinowski, Sławomir; Kojło, Anatol

2016-03-10

In this work, we present a novel chemiluminescence (CL) method based on direct-injection detector (DID) integrated with the multi-pumping flow system (MPFS) to chemiluminescence determination of the total polyphenol index. In this flow system, the sample and the reagents are injected directly into the cone-shaped detection cell placed in front of the photomultiplier window. Such construction of the detection chamber allows for fast measurement of the CL signal in stopped-flow conditions immediately after mixing the reagents. The proposed DID-CL-MPFS method is based on the chemiluminescence of nanocolloidal manganese(IV)-hexametaphosphate-ethanol system. The application of ethanol as a sensitizer, eliminated the use of carcinogenic formaldehyde. Under the optimized experimental conditions, the chemiluminescence intensities are proportional to the concentration of gallic acid in the range from 5 to 350 ng mL(-1). The DID-CL-MPFS method offers a number of advantages, including low limit of detection (0.80 ng mL(-1)), high precision (RSD = 3.3%) and high sample throughput (144 samples h(-1)) as well as low consumption of reagents, energy and low waste generation. The proposed method has been successfully applied to determine the total polyphenol index (expressed as gallic acid equivalent) in a variety of plant-derived food samples (wine, tea, coffee, fruit and vegetable juices, herbs, spices). Copyright © 2016 Elsevier B.V. All rights reserved.
Premixed direct injection disk

Science.gov (United States)

York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Lacy, Benjamin; Zuo, Baifang; Uhm, Jong Ho

2013-04-23

A fuel/air mixing disk for use in a fuel/air mixing combustor assembly is provided. The disk includes a first face, a second face, and at least one fuel plenum disposed therebetween. A plurality of fuel/air mixing tubes extend through the pre-mixing disk, each mixing tube including an outer tube wall extending axially along a tube axis and in fluid communication with the at least one fuel plenum. At least a portion of the plurality of fuel/air mixing tubes further includes at least one fuel injection hole have a fuel injection hole diameter extending through said outer tube wall, the fuel injection hole having an injection angle relative to the tube axis. The invention provides good fuel air mixing with low combustion generated NOx and low flow pressure loss translating to a high gas turbine efficiency, that is durable, and resistant to flame holding and flash back.
Injection characteristics study of high-pressure direct injector for Compressed Natural Gas (CNG) using experimental and analytical method

Science.gov (United States)

Taha, Z.; Rahim, MF Abdul; Mamat, R.

2017-10-01

The injection characteristics of direct injector affect the mixture formation and combustion processes. In addition, the injector is converted from gasoline operation for CNG application. Thus measurement of CNG direct injector mass flow rate was done by independently tested a single injector on a test bench. The first case investigated the effect of CNG injection pressure and the second case evaluate the effect of pulse-width of injection duration. An analytical model was also developed to predict the mass flow rate of the injector. The injector was operated in a choked condition in both the experiments and simulation studies. In case 1, it was shown that mass flow rate through the injector is affected by injection pressure linearly. Based on the tested injection pressure of 20 bar to 60 bar, the resultant mass flow rate are in the range of 0.4 g/s to 1.2 g/s which are met with theoretical flow rate required by the engine. However, in Case 2, it was demonstrated that the average mass flow rate at short injection durations is lower than recorded in Case 1. At injection pressure of 50 bar, the average mass flow rate for Case 2 and Case 1 are 0.7 g/s and 1.1 g/s respectively. Also, the measured mass flow rate at short injection duration showing a fluctuating data in the range of 0.2 g/s - 1.3 g/s without any noticeable trends. The injector model able to predict the trend of the mass flow rate at different injection pressure but unable to track the fluctuating trend at short injection duration.
Automation of radiochemical analysis by flow injection techniques. Am-Pu separation using TRU-resinTM sorbent extraction column

International Nuclear Information System (INIS)

Egorov, O.; Washington Univ., Seattle, WA; Grate, J.W.; Ruzicka, J.

1998-01-01

A rapid automated flow injection analysis (FIA) procedure was developed for efficient separation of Am and Pu from each other and from interfering matrix and radionuclide components using a TRU-resin TM column. Selective Pu elution is enabled via on-column reduction. The separation was developed using on-line radioactivity detection. After the separation had been developed, fraction collection was used to obtain the separated fractions. In this manner, a FIA instrument functions as an automated separation workstation capable of unattended operation. (author)
Vortex breakdown in a supersonic jet

Science.gov (United States)

Cutler, Andrew D.; Levey, Brian S.

1991-01-01

This paper reports a study of a vortex breakdown in a supersonic jet. A supersonic vortical jets were created by tangential injection and acceleration through a convergent-divergent nozzle. Vortex circulation was varied, and the nature of the flow in vortical jets was investigated using several types of flow visualization, including focusing schlieren and imaging of Rayleigh scattering from a laser light sheet. Results show that the vortical jet mixed much more rapidly with the ambient air than a comparable straight jet. When overexpanded, the vortical jet exhibited considerable unsteadiness and showed signs of vortex breakdown.
Axial-Flow Turbine Rotor Discharge-Flow Overexpansion and Limit-Loading Condition, Part I: Computational Fluid Dynamics (CFD) Investigation

Science.gov (United States)

Chen, Shu-Cheng S.

2017-01-01

A Computational Fluid Dynamic (CFD) investigation is conducted over a two-dimensional axial-flow turbine rotor blade row to study the phenomena of turbine rotor discharge flow overexpansion at subcritical, critical, and supercritical conditions. Quantitative data of the mean-flow Mach numbers, mean-flow angles, the tangential blade pressure forces, the mean-flow mass flux, and the flow-path total pressure loss coefficients, averaged or integrated across the two-dimensional computational domain encompassing two blade-passages, are obtained over a series of 14 inlet-total to exit-static pressure ratios, from 1.5 (un-choked; subcritical condition) to 10.0 (supercritical with excessively high pressure ratio.) Detailed flow features over the full domain-of-computation, such as the streamline patterns, Mach contours, pressure contours, blade surface pressure distributions, etc. are collected and displayed in this paper. A formal, quantitative definition of the limit loading condition based on the channel flow theory is proposed and explained. Contrary to the comments made in the historical works performed on this subject, about the deficiency of the theoretical methods applied in analyzing this phenomena, using modern CFD method for the study of this subject appears to be quite adequate and successful. This paper describes the CFD work and its findings.

Numerical analysis of MHD Casson Navier's slip nanofluid flow yield by rigid rotating disk

Science.gov (United States)

Rehman, Khalil Ur; Malik, M. Y.; Zahri, Mostafa; Tahir, M.

2018-03-01

An exertion is perform to report analysis on Casson liquid equipped above the rigid disk for z bar > 0 as a semi-infinite region. The flow of Casson liquid is achieve through rotation of rigid disk with constant angular frequency Ω bar . Magnetic interaction is consider by applying uniform magnetic field normal to the axial direction. The nanosized particles are suspended in the Casson liquid and rotation of disk is manifested with Navier's slip condition, heat generation/absorption and chemical reaction effects. The obtain flow narrating differential equations subject to MHD Casson nanofluid are transformed into ordinary differential system. For this purpose the Von Karman way of scheme is executed. To achieve accurate trends a computational algorithm is develop rather than to go on with usual build-in scheme. The effects logs of involved parameters, namely magnetic field parameter, Casson fluid parameter, slip parameter, thermophoresis and Brownian motion parameters on radial, tangential velocities, temperature, nanoparticles concentration, Nusselt and Sherwood numbers are provided by means of graphical and tabular structures. It is observed that both tangential and radial velocities are decreasing function of Casson fluid parameter.
Effect of cavitation in high-pressure direct injection

Science.gov (United States)

Aboulhasanzadeh, Bahman; Johnsen, Eric

2015-11-01

As we move toward higher pressures for Gasoline Direct Injection and Diesel Direct Injection, cavitation has become an important issue. To better understand the effect of cavitation on the nozzle flow and primary atomization, we use a high-order accurate Discontinuous Galerkin approach using multi-GPU parallelism to simulate the compressible flow inside and outside the nozzle. Phase change is included using the six-equations model. We investigate the effect of nozzle geometry on cavitation inside the injector and on primary atomization outside the nozzle.
Chemical reaction effect on an unsteady MHD free convection flow past a vertical porous plate in the presence of suction or injection

Directory of Open Access Journals (Sweden)

Shivaiah S.

2012-01-01

Full Text Available The objective of this paper is to analyze the effect of chemical reaction on unsteady magneto hydrodynamic free convective fluid flow past a vertical porous plate in the presence of suction or injection. The governing equations of the flow field are solved numerically by a finite element method. The effects of the various parameters on the velocity, temperature and concentration profiles are presented graphically and values of skin-friction coefficient, Nusselt number and Sherwood number for various values of physical parameters are presented through tables.
Water injection dredging

NARCIS (Netherlands)

Verhagen, H.J.

2000-01-01

Some twenty years ago WIS-dredging has been developed in the Netherlands. By injecting water into the mud layer, the water content of the mud becomes higher, it becomes fluid mud and will start to flow. The advantages of this system are that there is no need of transporting the mud in a hopper, and
A proposed through-flow inverse method for the design of mixed-flow pumps

Science.gov (United States)

Borges, Joao Eduardo

1991-01-01

A through-flow (hub-to-shroud) truly inverse method is proposed and described. It uses an imposition of mean swirl, i.e., radius times mean tangential velocity, given throughout the meridional section of the turbomachine as an initial design specification. In the present implementation, it is assumed that the fluid is inviscid, incompressible, and irrotational at inlet and that the blades are supposed to have zero thickness. Only blade rows that impart to the fluid a constant work along the space are considered. An application of this procedure to design the rotor of a mixed-flow pump is described in detail. The strategy used to find a suitable mean swirl distribution and the other design inputs is also described. The final blade shape and pressure distributions on the blade surface are presented, showing that it is possible to obtain feasible designs using this technique. Another advantage of this technique is the fact that it does not require large amounts of CPU time.
Contact problem on indentation of an elastic half-plane with an inhomogeneous coating by a flat punch in the presence of tangential stresses on a surface

Science.gov (United States)

Volkov, Sergei S.; Vasiliev, Andrey S.; Aizikovich, Sergei M.; Sadyrin, Evgeniy V.

2018-05-01

Indentation of an elastic half-space with functionally graded coating by a rigid flat punch is studied. The half-plane is additionally subjected to distributed tangential stresses. Tangential stresses are represented in a form of Fourier series. The problem is reduced to the solution of two dual integral equations over even and odd functions describing distribution of unknown normal contact stresses. The solutions of these dual integral equations are constructed by the bilateral asymptotic method. Approximated analytical expressions for contact normal stresses are provided.
Filterless preconcentration, flow injection analysis and detection by inductively-coupled plasma mass spectrometry

DEFF Research Database (Denmark)

Andersen, Jens Enevold Thaulov

The influence of interferences in the analysis of elements by inductively-coupled-plasma mass-spectrometry (ICP-MS) may be significantly diminished by utilising a protocol of flow-injection analysis (FIA). The method is based on filterless preconcentration of metallic elements at the walls...... of a knotted reactor that was made of nylon tubings. In the load mode, the preconcentration was accomplished by precipitation of metallic species in alkaline-buffered carriers onto the inner walls of the hydrofilic tube. After a preconcen-tration period of 40-120 seconds using sample volumes of 4-10 m...... of 10-30 were obtained in the analysis of aluminium, of chromium and of iron, which resulted in detection limits (3) down to 20 g/L at a sampling frequency of 50 per hour. The preconcentration protocol improves the selectivity thus allowing direct determination of the elements in saline media. Anionic...
Fast ion behavior during neutral beam injection in ATF

International Nuclear Information System (INIS)

Wade, M.R.; Thomas, C.E.; Colchin, R.J.; Rome, J.A.; England, A.C.; Fowler, R.H.; Aceto, S.C.

1993-01-01

In stellarators, single-particle confinement properties can be more complex than in their tokamak counterparts. Fast-ion behavior in tokamaks has been well characterized through an abundance of measurements on various devices and in general has been shown to be consistent with classical slowing-down theory, although anomalous ion behavior has been observed during intense beam injection in ISX-B, during fishbone instabilities in PDX, and in experiments on TFR. In contrast, fast ion behavior in stellarators is not as wel established experimentally with the primary experiments to date focusing o near-perpendicular or perpendicular neutral beam injection (NBI) on the Wendelstein 7-A stellarator (91 and Heliotron-E. This paper addresses fast-ion confinement properties in a large-aspect-ratio, moderate-shear stellarator, the Advanced Toroidal Facility, during tangential NBI. The primary data used in this study are the experimentally measured energy spectra of charge-exchange neutrals escaping from the plasma, using a two-dimensional scanning neutral particle analyzer. This diagnostic method is well established, having been used on several devices since the early 1970's. Various aspects of fast-ion behavior are investigated by comparing these data with computed theoretical spectra based on energeticion distributions derived from the fastion Fokker-Planck equation. Ion orbits are studied by computer orbit following, by the computation of J* surfaces, and by Monte Carlo calculations
CFD Validation of Gas Injection in Flowing Mercury over Vertical Smooth and Grooved Wall

International Nuclear Information System (INIS)

Abdou, Ashraf A.; Wendel, Mark W.; Felde, David K.; Riemer, Bernie

2009-01-01

The Spallation Neutron Source (SNS) is an accelerator-based neutron source at Oak Ridge National Laboratory (ORNL). The nuclear spallation reaction occurs when a proton beam hits liquid mercury. This interaction causes thermal expansion of the liquid mercury which produces high pressure waves. When these pressure waves hit the target vessel wall, cavitation can occur and erode the wall. Research and development efforts at SNS include creation of a vertical protective gas layer between the flowing liquid mercury and target vessel wall to mitigate the cavitation damage erosion and extend the life time of the target. Since mercury is opaque, computational fluid dynamics (CFD) can be used as a diagnostic tool to see inside the liquid mercury and guide the experimental efforts. In this study, CFD simulations of three dimensional, unsteady, turbulent, two-phase flow of helium gas injection in flowing liquid mercury over smooth, vertically grooved and horizontally grooved walls are carried out with the commercially available CFD code Fluent-12 from ANSYS. The Volume of Fluid (VOF) model is used to track the helium-mercury interface. V-shaped vertical and horizontal grooves with 0.5 mm pitch and about 0.7 mm depth were machined in the transparent wall of acrylic test sections. Flow visualization data of helium gas coverage through transparent test sections is obtained with a high-speed camera at the ORNL target test facility (TTF). The helium gas mass flow rate is 8 mg/min and introduced through a 0.5 mm diameter port. The local mercury velocity is 0.9 m/s. In this paper, the helium gas flow rate and the local mercury velocity are kept constant for the three cases. Time integration of predicted helium gas volume fraction over time is done to evaluate the gas coverage and calculate the average thickness of the helium gas layer. The predicted time-integrated gas coverage over vertically grooved and horizontally grooved test sections is better than over a smooth wall. The
Assessment of hand blood flow: a modified technique

International Nuclear Information System (INIS)

Kirsh, J.C.; Tepperman, P.S.

1985-01-01

A blood flow artifact has been identified with the conventional bolus-injection technique in radionuclide studies of hand disorders. The artifact, consisting of increased blood flow on the injected side, was demonstrated in 22 of 25 subjects. Using a modified injection technique to allow time for local blood flow to return to the basal state, the artifact could be eliminated in 19 of 23 additional subjects. Use of this simple protocol should help avoid misinterpretation of blood flow asymmetry in the assessment of hand disorders
The effect of intralesional steroid injections on the volume and blood flow in periocular capillary haemangiomas.

Science.gov (United States)

Verity, David H; Rose, Geoffrey E; Restori, M

2008-01-01

To examine the effect of steroid therapy on the volume estimates and blood flow characteristics of childhood periorbital capillary haemangiomas. Children at risk of amblyopia due to periorbital haemangiomas were treated with intralesional steroid injections (between 1 and 4 courses) and serial assessment of the volume and blood-flow characteristics of the lesions measured using colour Doppler ultrasonography. The characteristics of the haemangiomas in these children were compared with a cohort of untreated cases. Eight of nine treated children were female, this proportion being significantly different from the equal sex distribution of an untreated cohort (p suppression persisting for several months (between 5 and 20) before the lesion later displays the cyclic fluctuations in volume and flow seen with untreated lesions. All treated haemangiomas had some residual vascular anomaly, detectable on ultrasonography, at last follow-up--this being despite absence of clinical signs in most cases. Periorbital capillary haemangiomas requiring steroid therapy for risk of amblyopia were significantly commoner in females, were larger lesions and presented at an earlier age. Intralesional steroids appear to cause a reduction of blood flow, with a transient reduction in volume and a suppression of the natural cyclic variation seen without treatment. The changes after a course of steroid therapy appear to last for between 5 and 20 months, this period of suppression of the lesion probably being particularly useful during infancy and early childhood when the child is at greatest risk of amblyopia.
Rapid isolation of biomarkers for compound specific radiocarbon dating using high-performance liquid chromatography and flow injection analysis-atmospheric pressure chemical ionisation mass spectrometry

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Smittenberg, R.H.; Hopmans, E.C.; Schouten, S.

2002-01-01

Repeated semi-preparative normal-phase HPLC was performed to isolate selected biomarkers from sediment extracts for radiocarbon analysis. Flow injection analysis mass spectrometry was used for rapid analysis of collected fractions to evaluate the separation procedure, taking only 1 min per fraction.
Numerical Analysis on the Influence of Thermal Effects on Oil Flow Characteristic in High-Pressure Air Injection (HPAI Process

Directory of Open Access Journals (Sweden)

Hu Jia

2012-01-01

Full Text Available In previous laboratory study, we have shown the thermal behavior of Keke Ya light crude oil (Tarim oilfield, branch of CNPC for high-pressure air injection (HPAI application potential study. To clarify the influences of thermal effects on oil production, in this paper, we derived a mathematical model for calculating oil flow rate, which is based on the heat conduction property in porous media from the combustion tube experiment. Based on remarkably limited knowledge consisting of very global balance arguments and disregarding all the details of the mechanisms in the reaction zone, the local governing equations are formulated in a dimensionless form. We use finite difference method to solve this model and address the study by way of qualitative analysis. The time-space dimensionless oil flow rate (qD profiles are established for comprehensive studies on the oil flow rate characteristic affected by thermal effects. It also discusses how these findings will impact HPAI project performances, and several guidelines are suggested.
Tangential filtration technologies membrane and applications for the industry agribusiness

International Nuclear Information System (INIS)

Leone, Gian Paolo; Russo, Claudio

2015-01-01

The membrane tangential filtration technologies are separation techniques based on the use of semipermeable filters through which, under a pushing force, it is possible to achieve separation of components or suspended in solution as a function of their dimensional characteristics and / or chemical-physical. At the laboratories of the ENEA Research Center Casaccia, as part of the program activities of the Biotechnology and agro-industry division, were studied and developed various filtration processes to membrane in the food industry. The problems have been studied by following a vision sustainable overall, always trying to pair the purification treatment to that of recovery and reuse of water and high value-added components. Ultimate goal of the research conducted is to close the production circuit, ensuring a discharge cycle zero and turning in fact a so-called spread in first, from which to obtain new products. [it
Successful management with glue injection of arterial rupture seen during embolization of an arteriovenous malformation using a flow-directed catheter: a case report

Energy Technology Data Exchange (ETDEWEB)

Hong, Jong Won; Baik, Seung Kug; Shin, Mi Jung; Choi, Han Yong; Kim, Bong Gi [Wallace Memorial Baptist Hospital, Pusan (Korea, Republic of)

2000-12-01

We present a case in which an arterial rupture occurring during embolization of an arteriovenous malformation of the left occipital lobe with a flow-directed micro-catheter, was successfully sealed with a small amount of glue. We navigated a 1.8-Fr Magic catheter through the posterior cerebral artery, and during superselective test injection, extravasation was observed at the parieto-occipital branch. The catheter was not removed and the perforation site was successfully sealed with a small amount of glue injected through the same catheter. Prompt recognition and closure of the perforation site is essential for good prognosis. (author)
Water injection profiling

International Nuclear Information System (INIS)

Arnold, D.M.

1982-01-01

A method of neutron-gamma logging is described, in which water, injected in a cased well borehole with peforations, is irradiated with neutrons of 10 MeV or greater, and subsequent gamma radiation is detected by a pair of detectors along the borehole. Counting rates of detectors are analyzed in terms of two gamma ray energy windows. Linear flow velocity of fluid moving downward within the casing is used in conjunction with count rate data to determine volume flow rates of water moving in other directions. Apparatus includes a sonde with a neutron source and appropriate gamma sensors
Determination of trace elements in seawater by air-flow injection/ICP-MS with chelating resin preconcentration

International Nuclear Information System (INIS)

Lee, Kyue-Hyung; Ohshima, Mitsuko; Motomizu, Shoji

2002-01-01

Multielement determination of major to trace metals in a deep seawater malt was accomplished by inductively coupled plasma-mass spectrometry (ICP-MS) together with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Major elements, such as Na, K, Mg, and Ca, were measured by ICP-AES and normal continuos nebulization ICP-MS after sample dilution by 10 3 -10 6 fold. Fifteen trace elements in the concentrated metal solutions pretreated with cation-exchange resin or chelating resin could be simultaneously determined by air-flow injection/ICP-mass spectrometry (AFI/ICP-MS). Since the injection volume for AFI/ICP-MS was 25 μl, final samples volumes less than 500 μl were enough for several replicate measurements. Three different preconcentration methods assisted with AFI/ICP-MS were examined and could be successfully applied to a deep seawater malt. The analytical results of rate earth elements (REEs) and Co, Ni, Cu, Zn, Cd, and Pb obtained by AFI/ICP-MS coupled with disk filtration method using iminodiacetate (IDA)-type chelating resin were favorably agreed with the data obtained by AFI/ICP-MS coupled with column preconcentration method using chitosan-based chelating resin. (author)
The Field Radiated by a Ring Quasi-Array of an Infinite Number of Tangential or Radial Dipoles

DEFF Research Database (Denmark)

Knudsen, H. L.

1953-01-01

A homogeneous ring array of axial dipoles will radiate a vertically polarized field that concentrates to an increasing degree around the horizontal plane with increasing increment of the current phase per revolution. There is reason to believe that by using a corresponding antenna system with tan......A homogeneous ring array of axial dipoles will radiate a vertically polarized field that concentrates to an increasing degree around the horizontal plane with increasing increment of the current phase per revolution. There is reason to believe that by using a corresponding antenna system...... with tangential or radial dipoles, a field may be obtained that has a similar useful structure as the above-mentioned ring array, but which in contrast to the latter is essentially horizontally polarized. In this paper a systematic investigation has been made of the field from such an antenna system...... with tangential or radial dipoles. Recently it was stated in the literature that it is impossible to treat the general case where the increase of the current phase per revolution is arbitrarily large by using ordinary functions. The results obtained in this paper disprove this statement. A similar investigation...
An electrochemiluminescence-based fibre optic biosensor for choline flow injection analysis.

Science.gov (United States)

Tsafack, V C; Marquette, C A; Leca, B; Blum, L J

2000-01-01

A fibre optic biosensor based on luminol electrochemiluminescence (ECL) integrated in a flow injection analysis (FIA) system was developed for the detection of choline. The electrochemiluminescence of luminol was generated by a glassy carbon electrode polarised at +425 mV vs. a platinum pseudo-reference electrode. Choline oxidase (Chx) was immobilised either covalently on polyamide (ABC type) or on UltraBind preactivated membranes, or by physical entrapment in a photo-cross-linkable poly(vinyl alcohol) polymer (PVA-SbQ) alone or after absorption on a weak anion exchanger, DEAE (diethylaminoethyl) Sepharose. The optimisation of the reaction conditions and physicochemical parameters influencing the FIA biosensor response demonstrated that the choline biosensor exhibited the best performances in a 30 mM veronal buffer containing 30 mM KCl and 1.5 mM MgCl2, at pH 9. The use of a 0.5 ml min-1 flow rate enabled the measurement of choline by the membrane-based ECL biosensors in 8 or 5 min, with ABC or UltraBind membranes, respectively, whereas the measurement required only 3 min with the DEAE-PVA system. For comparison, the detection of choline was performed with Chx immobilised using the four different supports. The best performances were obtained with the DEAE-PVA-Chx sensing layer, which allowed a detection limit of 10 pmol, whereas with the ABC, the UltraBind and the PVA systems, the detection limits were 300 pmol, 75 pmol and 220 pmol, respectively. The DEAE-based system also exhibited a good operational stability since 160 repeated measurements of 3 nmol of choline could be performed with an RSD of 4.5% whereas the stability under the best conditions was 45 assays with the other supports.
Flow injection methods for the determination of a-tocopherol with spectrophotometric detection

International Nuclear Information System (INIS)

Rishi, L.; Waseem, A.; Yaqoob, M.; Nabi, A.; Jadoon, S.

2011-01-01

The present paper describes flow injection procedures for a-tocopherol determination in pharmaceuticals and infant milk powder based on spectrophotometric detection. These two procedures are based on the reduction of iron(III) to iron(II) and of Mo(Vi) to Mo(V) by a-tocopherol and subsequent formation of iron(II)-o-phenanthroline, and phospho molybdenum complexes which were monitored at 510 and 695 nm respectively. Calibration graphs were linear over the concentration range of 0.21-43 mu g/mL for iron(III) and 0.25-10 mu g/mL for Mo(Vi) reduction methods respectively. The limits of detection (3s) of 0.05 and 0.1 mu g/mL with sample throughput of 30 and 50/h respectively were obtained. The relative standard deviations of 1.2- 3.8% (n = 4) was achieved in the concentration range studied. The developed methods were applied to pharmaceuticals and infant milk powders and the results obtained were compared with official method and no significant difference between these methods was observed at 95% confidence level. (author)

Effect of double air injection on performance characteristics of centrifugal compressor

Science.gov (United States)

Hirano, Toshiyuki; Ogawa, Tatsuya; Yasui, Ryutaro; Tsujita, Hoshio

2017-02-01

In the operation of a centrifugal compressor of turbocharger, instability phenomena such as rotating stall and surge are induced at a lower flow rate close to the maximum pressure ratio. In this study, the compressed air at the exit of centrifugal compressor was re-circulated and injected to the impeller inlet by using two injection nozzles in order to suppress the surge phenomenon. The most effective circumferential position was examined to reduce the flow rate at the surge inception. Moreover, the influences of the injection on the fluctuating property of the flow field before and after the surge inception were investigated by examining the frequency of static pressure fluctuation on the wall surface and visualizing the compressor wall surface by oil-film visualization technique.
Polymeric microchip for the simultaneous determination of anions and cations by hydrodynamic injection using a dual-channel sequential injection microchip electrophoresis system.

Science.gov (United States)

Gaudry, Adam J; Nai, Yi Heng; Guijt, Rosanne M; Breadmore, Michael C

2014-04-01

A dual-channel sequential injection microchip capillary electrophoresis system with pressure-driven injection is demonstrated for simultaneous separations of anions and cations from a single sample. The poly(methyl methacrylate) (PMMA) microchips feature integral in-plane contactless conductivity detection electrodes. A novel, hydrodynamic "split-injection" method utilizes background electrolyte (BGE) sheathing to gate the sample flows, while control over the injection volume is achieved by balancing hydrodynamic resistances using external hydrodynamic resistors. Injection is realized by a unique flow-through interface, allowing for automated, continuous sampling for sequential injection analysis by microchip electrophoresis. The developed system was very robust, with individual microchips used for up to 2000 analyses with lifetimes limited by irreversible blockages of the microchannels. The unique dual-channel geometry was demonstrated by the simultaneous separation of three cations and three anions in individual microchannels in under 40 s with limits of detection (LODs) ranging from 1.5 to 24 μM. From a series of 100 sequential injections the %RSDs were determined for every fifth run, resulting in %RSDs for migration times that ranged from 0.3 to 0.7 (n = 20) and 2.3 to 4.5 for peak area (n = 20). This system offers low LODs and a high degree of reproducibility and robustness while the hydrodynamic injection eliminates electrokinetic bias during injection, making it attractive for a wide range of rapid, sensitive, and quantitative online analytical applications.
Effectiveness of In-Vessel Retention Strategies and Minimum Safety Injection Flow over Postulated Severe Accidents of OPR1000

International Nuclear Information System (INIS)

Kim, Sung Joong; Seo, Seungwon; Lee, Seongnyeon; KIm, Hwan Yeol; Ha, Kwang Soon; Park, Jonghwa; Park, Raejoon

2013-01-01

The objective of this study is first to evaluate various serious severe accident scenarios of OPR1000 with and without in-vessel retention strategies using MELCOR code. Second is to develop a mechanistic model of minimum safety injection flow using the thermal-hydraulic parameters of CET and collapsed water level obtained from the MELCOR simulation results. Effectiveness of RCS depressurization of OPR1000 is investigated for postulated severe accidents of SBLOCA, SBO, and TLOF. It is seen that timely operator action is important to achieve the best mitigation. Also The MELCOR simulation results of SBLOCA, SBO, and TLOFW are utilized to develop a model for minimum safety injection flow. The model suggests that if HPSI is available with RCS pressure lower than 120 bars, the core coolability can be guaranteed. In this study, several MELCOR simulations are conducted in search for effective in-vessel retention strategies over postulated severe accidents of SBLOCA, SBO, and TLOFW of OPR1000. Detailed accident sequences are presented and indicative parameters diagnosing the reactor thermal-hydraulic state are interrogated to provide useful information to the operator actions. To properly assist operator's action during the severe accident, the thermal-hydraulic parameters should be virtual, intuitive, and reliable. In addition, the parameters should be collected through the instrumentations close to the reactor core. In this regard, Core Exit Temperature (CET) and collapsed core water level are deemed as the commensurate parameters
Effectiveness of In-Vessel Retention Strategies and Minimum Safety Injection Flow over Postulated Severe Accidents of OPR1000

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Joong; Seo, Seungwon; Lee, Seongnyeon [Hanyang Univ., Seoul (Korea, Republic of); KIm, Hwan Yeol; Ha, Kwang Soon; Park, Jonghwa; Park, Raejoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

The objective of this study is first to evaluate various serious severe accident scenarios of OPR1000 with and without in-vessel retention strategies using MELCOR code. Second is to develop a mechanistic model of minimum safety injection flow using the thermal-hydraulic parameters of CET and collapsed water level obtained from the MELCOR simulation results. Effectiveness of RCS depressurization of OPR1000 is investigated for postulated severe accidents of SBLOCA, SBO, and TLOF. It is seen that timely operator action is important to achieve the best mitigation. Also The MELCOR simulation results of SBLOCA, SBO, and TLOFW are utilized to develop a model for minimum safety injection flow. The model suggests that if HPSI is available with RCS pressure lower than 120 bars, the core coolability can be guaranteed. In this study, several MELCOR simulations are conducted in search for effective in-vessel retention strategies over postulated severe accidents of SBLOCA, SBO, and TLOFW of OPR1000. Detailed accident sequences are presented and indicative parameters diagnosing the reactor thermal-hydraulic state are interrogated to provide useful information to the operator actions. To properly assist operator's action during the severe accident, the thermal-hydraulic parameters should be virtual, intuitive, and reliable. In addition, the parameters should be collected through the instrumentations close to the reactor core. In this regard, Core Exit Temperature (CET) and collapsed core water level are deemed as the commensurate parameters.
Resin Viscosity Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

Science.gov (United States)

Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

2018-06-01

Viscosity of the liquid resin effects the chemical and mechanical properties of the pultruded composite. In resin injection pultrusion manufacturing the liquid resin is injected into a specially designed tapered injection chamber through the injection slots present on top and bottom of the chamber. The resin is injected at a pressure so as to completely wetout the fiber reinforcements inside the tapered injection chamber. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the center of chamber causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to efficaciously penetrate through the compacted fibers and achieve complete wetout. The impact of resin viscosity on resin flow, fiber compaction, wetout and on the final product is further discussed. Injection chamber design predominantly effects the resin flow inside the chamber and the minimum injection pressure required to completely wet the fibers. Therefore, a desirable injection chamber design is such that wetout occurs at lower injection pressures and at low internal pressures inside the injection chamber.
Determinação potenciométrica em fluxo de cloreto de cetilpiridinio em desinfectantes bucais Potentiometric determination of cetylpyridinium chloride in oral desinfectants by flow injection analysis

Directory of Open Access Journals (Sweden)

Paula C. S. Baptista

2003-08-01

Full Text Available The work describes a new procedure for cetylpyridinium chloride determination in oral disinfectants, based on a flow-injection system with potentiometric detection. The determination was based on the measurement of picrate concentration decrease as result of ion-pair reaction with the analyte present in the injected sample. In the optimised set-up the sample injection volume was kept at 400 µL and merged downstream with the reagent solution containing 1,0 x10-5 mol/L of picrate adjusted to pH 5.0 with citrate/citric acid buffer. The flow rate was fixed at 8 mL/min and the reactor length at 40 cm. The proposed procedure enables the determination of cetylpyridinium in the analytical range of 5,0x10-6 - 7,5x10-5 mol/L at a sampling rate of 60/h. The results for real samples had a precision better than 3% and were comparable to the labelled values.
Simple flow injection for determination of sulfite by amperometric detection using glassy carbon electrode modified with carbon nanotubes-PDDA-gold nanoparticles.

Science.gov (United States)

Amatatongchai, Maliwan; Sroysee, Wongduan; Chairam, Sanoe; Nacapricha, Duangjai

2015-02-01

A new approach is presented for sensitive and selective measurement of sulfite (SO3(2-)) in beverages based on a simple flow injection system with amperometric detection. In this work, the sulfite sensor was a glassy carbon electrode modified with multiwall carbon nanotubes-poly(diallyldimethylammonium chloride)-gold nanoparticles composites (CNTs-PDDA-AuNPs/GC). Electrochemical oxidation of sulfite with this electrode was first studied in 0.1M phosphate buffer (pH 7.0) using cyclic voltammetry. The results indicated that the CNTs-PDDA-AuNPs/GC electrode possesses electrocatalytic activity for the oxidation of sulfite with high sensitivity and selectivity. Sulfite was quantified using amperometric measurement with the new sensor at +0.4V vs Ag/AgCl in conjunction with flow injection. The linear working range for the quantitation of sulfite was 2-200 mg L(-1) (r(2)=0.998) with a detection limit of 0.03 mg L(-1) (3σ of blank) and an estimated precision of 1.5%.The proposed method was successfully applied to the determination of sulfite in fruit juices and wines with a sample throughput of 23 samples per hour. Copyright © 2014 Elsevier B.V. All rights reserved.
Simultaneous detection of selenium by atomic fluorescence and sulfur by molecular emission by flow-injection hydride generation with on-line reduction for the determination of selenate, sulfate and sulfite

Energy Technology Data Exchange (ETDEWEB)

Tyson, J.F., E-mail: tyson@chem.umass.edu [Department of Chemistry, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Palmer, C.D. [Lead Poisoning Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, P.O. Box 509, Empire State Plaza, Albany, NY 12201-0509 (United States)

2009-10-12

An inductively coupled plasma atomic fluorescence spectrometry (ICP-AFS) instrument, was modified so that it was capable of monitoring transient chromatographic or flow-injection profiles and that sulfur molecular emission and selenium atomic fluorescence could be monitored simultaneously in an argon-hydrogen diffusion flame on a glass burner. The analytes were introduced as hydrogen selenide and hydrogen sulfide, generated on a flow-injection manifold. Selenate was reduced to hydride-forming selenite by microwave-assisted on-line reaction with hydrochloric acid, and sulfate, or sulfite, was reduced to hydride-forming sulfide by a mixture of hydriodic acid, acetic acid and sodium hypophosphite. The effects of the nature of reducing agent, flow rate, microwave power and coil length were studied. The limit of detection (3 s) for selenium was 10 {mu}g L{sup -1}, and for sulfide was 70 {mu}g L{sup -1} (200-{mu}L injection volume). The calibration was linear for selenium up to 2 mg L{sup -1} and to 10 mg L{sup -1} for sulfide. The throughput was 180 h{sup -1}. The three sulfur species could be differentiated on the basis of reactivity at various microwave powers.
Steady flow in a porous layer subjected to a stream uniformly injecting from a plane; Ichiyo ni men kara fukidasu nagare ni sarasareta takoshitsu sonai no teijo nagare

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, E; Horiguchi, Y; Kitazawa, K [Keio University, Tokyo (Japan). Faculty of Science and Technology

1997-08-25

A steady flow in an non-deformable porous layer subjected to a fluid stream is studied analytically and numerically. One side of the layer of sponge is bounded by a solid wall and the other by a layer of fluid. The fluid is injected uniformly from a plane, through which the fluid can pass, set up parallel to the sponge layer. The flow in the sponge layer is assumed to be governed by Darcy`s law. The problem considered is solved in terms of a similarity solution. The equations governing the fluid flows in both the porous layer and the fluid layer are reduced to a system of the ordinary differential equations. These equations are solved analytically for three cases ideal fluid flow, low Reynolds number flow and high Reynolds number flow. On the other hand, these equations are solved numerically for the general case by using the finite difference method. The distributions of the velocity and the pressure in both layers are found for various parameters. In particular, the speed which the fluid intrudes into the sponge layer due to the injection of the stream from the plane is found to be a function of dimensionless parameters. To find this speed is essential to the understanding of porous material. 15 refs., 9 figs.
Investigation on transient flow of a centrifugal charging pump in the process of high pressure safety injection

Energy Technology Data Exchange (ETDEWEB)

Zhang, Fan, E-mail: zhangfan4060@gmail.com; Yuan, Shouqi; Fu, Qiang; Tao, Yi

2015-11-15

Highlights: • The transient flow characteristics of the charging pump with the first stage impeller in the HPSI process have been investigated numerically by CFD. • The hydraulic performance of the charging pump during the HPSI are discussed, andthe absolute errors between the simulated and measured results are analyzed in the paper. • Pressure fluctuation in the impeller and flow pattern in the impeller were studied in the HPSI process. It is influenced little at the beginning of the HPSI process while fluctuates strongly in the end of the HPSI process. - Abstract: In order to investigate the transient flow characteristics of the centrifugal charging pump during the transient transition process of high pressure safety injection (HPSI) from Q = 148 m{sup 3}/h to Q = 160 m{sup 3}/h, numerical simulation and experiment are implemented in this study. The transient flow rate, which is the most important factor, is obtained from the experiment and works as the boundary condition to accurately accomplish the numerical simulation in the transient process. Internal characteristics under the variable operating conditions are analyzed through the transient simulation. The results shows that the absolute error between the simulated and measured heads is less than 2.26% and the absolute error between the simulated and measured efficiency is less than 2.04%. Pressure fluctuation in the impeller is less influenced by variable flow rate in the HPSI process, while flow pattern in the impeller is getting better and better with the flow rate increasing. As flow rate increases, fluid blocks on the tongue of the volute and it strikes in this area at large flow rate. Correspondingly, the pressure fluctuation is intense and vortex occurs gradually during this period, which obviously lowers the efficiency of the pump. The contents of the current work can provide references for the design optimization and fluid control of the pump used in the transient process of variable operating
Investigation on transient flow of a centrifugal charging pump in the process of high pressure safety injection

International Nuclear Information System (INIS)

Zhang, Fan; Yuan, Shouqi; Fu, Qiang; Tao, Yi

2015-01-01

Highlights: • The transient flow characteristics of the charging pump with the first stage impeller in the HPSI process have been investigated numerically by CFD. • The hydraulic performance of the charging pump during the HPSI are discussed, andthe absolute errors between the simulated and measured results are analyzed in the paper. • Pressure fluctuation in the impeller and flow pattern in the impeller were studied in the HPSI process. It is influenced little at the beginning of the HPSI process while fluctuates strongly in the end of the HPSI process. - Abstract: In order to investigate the transient flow characteristics of the centrifugal charging pump during the transient transition process of high pressure safety injection (HPSI) from Q = 148 m"3/h to Q = 160 m"3/h, numerical simulation and experiment are implemented in this study. The transient flow rate, which is the most important factor, is obtained from the experiment and works as the boundary condition to accurately accomplish the numerical simulation in the transient process. Internal characteristics under the variable operating conditions are analyzed through the transient simulation. The results shows that the absolute error between the simulated and measured heads is less than 2.26% and the absolute error between the simulated and measured efficiency is less than 2.04%. Pressure fluctuation in the impeller is less influenced by variable flow rate in the HPSI process, while flow pattern in the impeller is getting better and better with the flow rate increasing. As flow rate increases, fluid blocks on the tongue of the volute and it strikes in this area at large flow rate. Correspondingly, the pressure fluctuation is intense and vortex occurs gradually during this period, which obviously lowers the efficiency of the pump. The contents of the current work can provide references for the design optimization and fluid control of the pump used in the transient process of variable operating conditions.
Influence of gas injection on viscous and viscoelastic properties of Xanthan gum.

Science.gov (United States)

Bobade, Veena; Cheetham, Madalyn; Hashim, Jamal; Eshtiaghi, Nicky

2018-05-01

Xanthan gum is widely used as a model fluid for sludge to mimic the rheological behaviour under various conditions including impact of gas injection in sludge. However, there is no study to show the influence of gas injection on rheological properties of xanthan gum specifically at the concentrations at which it is used as a model fluid for sludge with solids concentration above 2%. In this paper, the rheological properties of aqueous xanthan gum solutions at different concentrations were measured over a range of gas injection flow rates. The effect of gas injection on both the flow and viscoelastic behaviour of Xanthan gum (using two different methods - a creep test and a time sweep test) was evaluated. The viscosity curve of different solid concentrations of digested sludge and waste activated sludge were compared with different solid concentrations of Xanthan gum and the results showed that Xanthan gum can mimic the flow behaviour of sludge in flow regime. The results in linear viscoelastic regime showed that increasing gas flow rate increases storage modulus (G'), indicating an increase in the intermolecular associations within the material structure leading to an increase in material strength and solid behaviour. Similarly, in creep test an increase in the gas flow rate decreased strain%, signifying that the material has become more resistant to flow. Both observed behaviour is opposite to what occurs in sludge under similar conditions. The results of both the creep test and the time sweep test indicated that choosing Xanthan gum aqueous solution as a transparent model fluid for sludge in viscoelastic regime under similar conditions involving gas injection in a concentration range studied is not feasible. However Xanthan gum can be used as a model material for sludge in flow regime; because it shows a similar behaviour to sludge. Copyright © 2018 Elsevier Ltd. All rights reserved.
Numerical simulation of internal and near-nozzle flow of a gasoline direct injection fuel injector

Science.gov (United States)

Saha, Kaushik; Som, Sibendu; Battistoni, Michele; Li, Yanheng; Quan, Shaoping; Senecal, Peter Kelly

2015-12-01

A numerical study of two-phase flow inside the nozzle holes and the issuing spray jets for a multi-hole direct injection gasoline injector has been presented in this work. The injector geometry is representative of the Spray G nozzle, an eight-hole counterbore injector, from, the Engine Combustion Network (ECN). Simulations have been carried out for the fixed needle lift. Effects of turbulence, compressibility and, non-condensable gases have been considered in this work. Standard k—ɛ turbulence model has been used to model the turbulence. Homogeneous Relaxation Model (HRM) coupled with Volume of Fluid (VOF) approach has been utilized to capture the phase change phenomena inside and outside the injector nozzle. Three different boundary conditions for the outlet domain have been imposed to examine non-flashing and evaporative, non-flashing and non-evaporative, and flashing conditions. Inside the nozzle holes mild cavitation-like and in the near-nozzle region flash boiling phenomena have been predicted in this study when liquid fuel is subjected to superheated ambiance. Noticeable hole to hole variation has been also observed in terms of mass flow rates for all the holes under both flashing and non-flashing conditions.
On-line monitoring of glucose and/or lactate in a fermentation process using an expanded micro-bed flow injection analyser.

Science.gov (United States)

Nandakumar, M P; Lali, A M; Mattiasson, B

1999-01-01

A novel flow injection biosensor system for monitoring fermentation processes has been developed using an expanded micro bed as the enzyme reactor. An expanded bed reactor is capable of handling a mobile phase containing suspended matter like cells and cell debris. Thus, while the analyte is free to interact with the adsorbent, the suspended particulate matter passes through unhindered. With the use of a scaled down expanded bed in the flow injection analysis (FIA) system, it was possible to analyse samples directly from a fermentor without the pretreatment otherwise required to extract the analyte or remove the suspended cells. This technique, therefore, provides a means to determine the true concentrations of the metabolites in a fermentor, with more ease than possible with other techniques. Glucose oxidase immobilised on STREAMLINE was used to measure glucose concentration in a suspension of dead yeast cells. There was no interference from the cell particles even at high cell densities such as 15 gm dry weight per litre. The assay time was about 6 min. Accuracy and reproducibility of the system was found to be good. In another scheme, lactate oxidase was covalently coupled to STREAMLINE for expanded bed operation. With the on-line expanded micro bed FIA it was possible to follow the fermentation with Lactobacillus casei.
A novel flow injection chemiluminescence method for automated and miniaturized determination of phenols in smoked food samples.

Science.gov (United States)

Vakh, Christina; Evdokimova, Ekaterina; Pochivalov, Aleksei; Moskvin, Leonid; Bulatov, Andrey

2017-12-15

An easily performed fully automated and miniaturized flow injection chemiluminescence (CL) method for determination of phenols in smoked food samples has been proposed. This method includes the ultrasound assisted solid-liquid extraction coupled with gas-diffusion separation of phenols from smoked food sample and analytes absorption into a NaOH solution in a specially designed gas-diffusion cell. The flow system was designed to focus on automation and miniaturization with minimal sample and reagent consumption by inexpensive instrumentation. The luminol - N-bromosuccinimide system in an alkaline medium was used for the CL determination of phenols. The limit of detection of the proposed procedure was 3·10 -8 ·molL -1 (0.01mgkg -1 ) in terms of phenol. The presented method demonstrated to be a good tool for easy, rapid and cost-effective point-of-need screening phenols in smoked food samples. Copyright © 2017 Elsevier Ltd. All rights reserved.
Flow injection gas chromatography with sulfur chemiluminescence detection for the analysis of total sulfur in complex hydrocarbon matrixes.

Science.gov (United States)

Hua, Yujuan; Hawryluk, Myron; Gras, Ronda; Shearer, Randall; Luong, Jim

2018-01-01

A fast and reliable analytical technique for the determination of total sulfur levels in complex hydrocarbon matrices is introduced. The method employed flow injection technique using a gas chromatograph as a sample introduction device and a gas phase dual-plasma sulfur chemiluminescence detector for sulfur quantification. Using the technique described, total sulfur measurement in challenging hydrocarbon matrices can be achieved in less than 10 s with sample-to-sample time ideal for fast analysis or trace sulfur analysis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Flow injection determination of lead and cadmium in hair samples from workers exposed to welding fumes

International Nuclear Information System (INIS)

Cespon-Romero, R.M.; Yebra-Biurrun, M.C.

2007-01-01

A flow injection procedure involving continuous acid leaching for lead and cadmium determination in hair samples of persons in permanent contact with a polluted workplace environment by flame atomic absorption spectrometry is proposed. Variables such as sonication time, nature and concentration of the acid solution used as leaching solution, leaching temperature, flow-rate of the continuous manifold, leaching solution volume and hair particle size were simultaneously studied by applying a Plackett-Burman design approach. Results showed that nitric acid concentration (leaching solution), leaching temperature and sonication time were statistically significant variables (confidence interval of 95%). These last two variables were finally optimised by using a central composite design. The proposed procedure allowed the determination of cadmium and lead with limits of detection 0.1 and 1.0 μg g -1 , respectively. The accuracy of the developed procedure was evaluated by the analysis of a certified reference material (CRM 397, human hair, from the BCR). The proposed method was applied with satisfactory results to the determination of Cd and Pb in human hair samples of workers exposed to welding fumes
Oxygen injection facility

International Nuclear Information System (INIS)

Ota, Masamoto; Hirose, Yuki

1998-01-01

A compressor introduces air as a starting material and sends it to a dust removing device, a dehumidifying device and an adsorption/separation system disposed downstream. The facility of the present invention is disposed in the vicinity of an injection point and installed in a turbine building of a BWR type reactor having a pipeline of a feedwater system to be injected. The adsorbing/separation system comprises an adsorbing vessel and an automatic valve, and the adsorbing vessel is filled with an adsorbent for selectively adsorbing nitrogen. Zeolite is used as the adsorbent. Nitrogen in the air passing through the adsorbing vessel is adsorbed and removed under a pressurized condition, and a highly concentrated oxygen gas is formed. The direction of the steam of the adsorbed nitrogen is changed by an opening/closing switching operation of an automatic valve and released to the atmosphere (the pressure is released). Generated oxygen gas is stored under pressure in a tank, and injected to the pipeline of the feedwater system by an oxygen injection conduit by way of a flow rate control valve. In the adsorbing vessel, steps of adsorption, separation and storage under pressure are repeated successively. (I.N.)
An investigation of fluid mixing with safety injection in advanced reactors

International Nuclear Information System (INIS)

Cha, Jong Hee; Won, Soon Yean; Chung, Moon Ki; Jun, Hyung Gil

1994-01-01

The objective of this work is to investigate the fluid mixing phenomena in aspect of pressurized thermal shock(PTS) in an advanced PWR vessel downcomer during transient cooldown with safety injection. It provides comparison of fluid mixing characteristics between AP 600 DVI, designed by Westinghouse, and ABB CE System 80+ DVI, and the effects of deflector at the reactor downcomer. In order to investigate the fluid mixing phenomena in the downcomer of an advanced PWR, the flow visualization tests and the salt concentration tests were conducted in a 1/7-scale acrylic transparent model, which was designed and built based on AP 600 reactor geometry. The behaviour of the safety injection flow in downcomer associated with mixing phenomenon can be observed during visualization test, and time-dependent mixing rate between safety injection fluid and existing coolant can be determined with concentration test. Visualization tests were performed by the dye injection method. The results of concentration measurements were compared with the calculation using the REMIX code. During the tests, difference between AP 600 DVI flow and ABB CE System 80+ DVI flow and the effect of the deflector were observed
Development of an automated technique for the speciation of arsenic using flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS)

Energy Technology Data Exchange (ETDEWEB)

Ruede, T.R. (Inst. of Petrography and Geochemistry, Univ. of Karlsruhe (Germany)); Puchelt, H. (Inst. of Petrography and Geochemistry, Univ. of Karlsruhe (Germany))

1994-09-01

An automated method for the determination of arsenic acid (AsV), arsenous acid (AsIII), monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA) was developed using a commercial available flow injection hydride generation system. By carrying out the hydride generation in selected acid media the determination of As(III) alone, of MMAA and DMAA by sum and by different sensitivities, and of all four species is possible. (orig.)

Use of flow injection mass spectrometric fingerprinting and chemometrics for differentiation of three black cohosh species

International Nuclear Information System (INIS)

Huang, Huilian; Sun, Jianghao; McCoy, Joe-Ann; Zhong, Haiyan; Fletcher, Edward J.; Harnly, James; Chen, Pei

2015-01-01

Flow injection mass spectrometry (FIMS) was used to provide chemical fingerprints of black cohosh (Actaea racemosa L.) in a manner of minutes by omitting the separation step. This method has proven to be a powerful tool for botanical authentication and in this study it was used to distinguish between three Actaea species prior to a more detailed chemical analysis using ultra high-performance liquid chromatography high-resolution mass spectrometry (UHPLC–HRMS). Black cohosh has become increasingly popular as a dietary supplement in the United States for the treatment of symptoms related to menopause. However, it has been known to be adulterated with the Asian Actaea dahurica (Turcz. ex Fisch. & C.A.Mey.) Franch. species (syn. Cimicifuga dahurica (Turcz.) Maxim). Existing methods for identification of black cohosh and differentiation of Actaea species are usually lengthy, laborious, and lack robustness, often based on the comparison of a few pre-selected components. Chemical fingerprints were obtained for 77 black cohosh samples and their related species using FIMS in the negative ion mode. The analysis time for each sample was less than 2 min. All data were processed using principal component analysis (PCA). FIMS fingerprints could readily differentiate all three species. Representative samples from each of the three species were further examined using UHPLC–MS to provide detailed profiles of the chemical differences between the three species and were compared to the PCA loadings. This study demonstrates a simple, fast, and easy analytical method that can be used to differentiate A. racemosa, Actaea podocarpa, and A. dahurica. - Highlights: • Flow injection mass spectrometry (FIMS) was used to provide chemical fingerprints of black cohosh (Actaea racemosa L.) in a manner of minutes by omitting the separation step. • FIMS can discriminate between A. dahurica, A. podocarpa, and A. racemosa. • FIMS is a valuable screening tool for authentication of botanicals
Use of flow injection mass spectrometric fingerprinting and chemometrics for differentiation of three black cohosh species

Energy Technology Data Exchange (ETDEWEB)

Huang, Huilian [Food Composition and Methods Development Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD (United States); Key Laboratory of Modern Preparation of TCM, Jiangxi University of Traditional Chinese Medicine, Ministry of Education, Nanchang, Jiangxi Province (China); Sun, Jianghao [Food Composition and Methods Development Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD (United States); McCoy, Joe-Ann [The North Carolina Arboretum Germplasm Repository, UNC Affiliate Campus, Asheville, NC (United States); Zhong, Haiyan [College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan Province (China); Fletcher, Edward J. [Strategic Sourcing, Inc., Banner Elk, NC 28604 (United States); Harnly, James, E-mail: harnly.james@ars.usda.gov [Food Composition and Methods Development Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD (United States); Chen, Pei, E-mail: pei.chen@ars.usda.gov [Food Composition and Methods Development Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD (United States)

2015-03-01

Flow injection mass spectrometry (FIMS) was used to provide chemical fingerprints of black cohosh (Actaea racemosa L.) in a manner of minutes by omitting the separation step. This method has proven to be a powerful tool for botanical authentication and in this study it was used to distinguish between three Actaea species prior to a more detailed chemical analysis using ultra high-performance liquid chromatography high-resolution mass spectrometry (UHPLC–HRMS). Black cohosh has become increasingly popular as a dietary supplement in the United States for the treatment of symptoms related to menopause. However, it has been known to be adulterated with the Asian Actaea dahurica (Turcz. ex Fisch. & C.A.Mey.) Franch. species (syn. Cimicifuga dahurica (Turcz.) Maxim). Existing methods for identification of black cohosh and differentiation of Actaea species are usually lengthy, laborious, and lack robustness, often based on the comparison of a few pre-selected components. Chemical fingerprints were obtained for 77 black cohosh samples and their related species using FIMS in the negative ion mode. The analysis time for each sample was less than 2 min. All data were processed using principal component analysis (PCA). FIMS fingerprints could readily differentiate all three species. Representative samples from each of the three species were further examined using UHPLC–MS to provide detailed profiles of the chemical differences between the three species and were compared to the PCA loadings. This study demonstrates a simple, fast, and easy analytical method that can be used to differentiate A. racemosa, Actaea podocarpa, and A. dahurica. - Highlights: • Flow injection mass spectrometry (FIMS) was used to provide chemical fingerprints of black cohosh (Actaea racemosa L.) in a manner of minutes by omitting the separation step. • FIMS can discriminate between A. dahurica, A. podocarpa, and A. racemosa. • FIMS is a valuable screening tool for authentication of botanicals.
Comparative investigation of five nanoparticles in flow of viscous fluid with Joule heating and slip due to rotating disk

Science.gov (United States)

Qayyum, Sumaira; Khan, Muhammad Ijaz; Hayat, Tasawar; Alsaedi, Ahmed

2018-04-01

Present article addresses the comparative study for flow of five water based nanofluids. Flow in presence of Joule heating is generated by rotating disk with variable thickness. Nanofluids are suspension of Silver (Ag), Copper (Cu), Copper oxide (CuO), Aluminum oxide or Alumina (Al2O3), Titanium oxide or titania (TiO2) and water. Boundary layer approximation is applied to partial differential equations. Using Von Karman transformations the partial differential equations are converted to ordinary differential equations. Convergent series solutions are obtained. Graphical results are presented to examine the behaviors of axial, radial and tangential velocities, temperature, skin friction and Nusselt number. It is observed that radial, axial and tangential velocities decay for slip parameters. Axial velocity decays for larger nanoparticle volume fraction. Effect of nanofluids on velocities dominant than base material. Temperature rises for larger Eckert number and temperature of silver water nanofluid is more because of its higher thermal conductivity. Surface drag force reduces for higher slip parameters. Transfer of heat is more for larger disk thickness index.
The tangential velocity of M31: CLUES from constrained simulations

Science.gov (United States)

Carlesi, Edoardo; Hoffman, Yehuda; Sorce, Jenny G.; Gottlöber, Stefan; Yepes, Gustavo; Courtois, Hélène; Tully, R. Brent

2016-07-01

Determining the precise value of the tangential component of the velocity of M31 is a non-trivial astrophysical issue that relies on complicated modelling. This has recently lead to conflicting estimates, obtained by several groups that used different methodologies and assumptions. This Letter addresses the issue by computing a Bayesian posterior distribution function of this quantity, in order to measure the compatibility of those estimates with Λ cold dark matter (ΛCDM). This is achieved using an ensemble of Local Group (LG) look-alikes collected from a set of constrained simulations (CSs) of the local Universe, and a standard unconstrained ΛCDM. The latter allows us to build a control sample of LG-like pairs and to single out the influence of the environment in our results. We find that neither estimate is at odds with ΛCDM; however, whereas CSs favour higher values of vtan, the reverse is true for estimates based on LG samples gathered from unconstrained simulations, overlooking the environmental element.
Simultaneous injection effective mixing flow analysis of urinary albumin using dye-binding reaction.

Science.gov (United States)

Ratanawimarnwong, Nuanlaor; Ponhong, Kraingkrai; Teshima, Norio; Nacapricha, Duangjai; Grudpan, Kate; Sakai, Tadao; Motomizu, Shoji

2012-07-15

A new four-channel simultaneous injection effective mixing flow analysis (SIEMA) system has been assembled for the determination of urinary albumin. The SIEMA system consisted of a syringe pump, two 5-way cross connectors, four holding coils, five 3-way solenoid valves, a 50-cm long mixing coil and a spectrophotometer. Tetrabromophenol blue anion (TBPB) in Triton X-100 micelle reacted with albumin at pH 3.2 to form a blue ion complex with a λ(max) 625nm. TBPB, Triton X-100, acetate buffer and albumin standard solutions were aspirated into four individual holding coils by a syringe pump and then the aspirated zones were simultaneously pushed in the reverse direction to the detector flow cell. Baseline drift, due to adsorption of TBPB-albumin complex on the wall of the hydrophobic PTFE tubing, was minimized by aspiration of Triton X-100 and acetate buffer solutions between samples. The calibration graph was linear in the range of 10-50μg/mL and the detection limit for albumin (3σ) was 0.53μg/mL. The RSD (n=11) at 30μg/mL was 1.35%. The sample throughput was 37/h. With a 10-fold dilution, interference from urine matrix was removed. The proposed method has advantages in terms of simple automation operation and short analysis time. Copyright © 2012 Elsevier B.V. All rights reserved.
CFD study of leakage flows in shroud cavities of a compressor impeller

Science.gov (United States)

Soldatova, K.

2017-08-01

The flow character in a gap between shroud disc of an impeller and a stator surface (shroud cavity) influences disc friction loss, labyrinth seal loss (parasitic losses) and thrust force. Flow calculations inside the shroud cavity of a model of centrifugal compressor stage and its labyrinth seal in a range of flow rates and axial width and radial gap are presented. The results are presented in terms of non-dimensional coefficients of flow, disc friction and seal leakage losses coefficients and pressure coefficient. The distributions meridional and tangential flow velocities correspond to the continuity and equilibrium equations - flow radial circulation exists in wide cavity and is absent in narrow cavities. The radial pressure distributions as measured and calculated are not fully comparable. The possible reason is that CFD-calculated leakage coefficient is less than calculated by A.Stodola formula. The influence of a cavity width on the losses and the thrust force requires a balanced design.
Theoretical study of hydraulic jump during circular horizontal hot leg injection in pressurized water reactor

International Nuclear Information System (INIS)

El Hawary, Shehab; Abu-Elyazeed, Osayed S.M.; Fahmy, Adel Alyan; Meglaa, Khairy

2016-01-01

Highlights: • The model is developed to predict the occurrence of onset hydraulic jump in a circular pipe. • Theoretical results are in agreement with experimental results and theory. • Effects of diameter of the injection pipe, Froude number and injected coolant mass are studied. - Abstract: One important phenomenon occurring during Loss of Coolant Accident (LOCA) is Counter-Current Flow Limitation (CCFL). The incidence of such CCFL is introduced by the onset of hydraulic jump. In the present work, a one dimensional model was modified to fit circular hot channel. The model was used to study the factors affecting the initial Froude number, the location of the occurrence of the hydraulic jump, and the critical coolant flow depth during circular horizontal hot leg injection in US-APWR Mitsubishi Reactor. The results showed good agreement with published experimental data of the Upper Plenum Test Facility (UPTF) at Mannheim, Germany. It was found that higher injected coolant mass flow rate increases the initial Froude number, the location of the occurrence of the hydraulic jump, and the critical injection depth divided by the diameter of the injection pipe. Such behavior is thought to be due to the increase of the inertia force by increasing of the injected coolant mass flow rate and the inverse of the diameter of the injection pipe. It was found also that, the location of the occurrence of hydraulic jump increases with decreasing load effect. Therefore, these results reveal that the avoidance of CCFL as well as hydraulic jump through hot leg at maximum load can be achieved by decreasing the distance between the injection point and the pressure vessel to below 0.3 m, and with diameter of 4 in (10.16 cm) as the design diameter of the injection pipe in US-APWR Mitsubishi Reactor. Moreover, the maximum critical depth (56 cm) is less than the diameter of the hot leg (78.74 cm) at an injected coolant mass flow of 400 kg/s, and with diameter of 4 in (10.16 cm) as the
Arterio-venous concentration difference of [51Cr]EDTA after a single injection in man. Significance of renal function and local blood flow

DEFF Research Database (Denmark)

Rehling, M; Hyldstrup, L; Henriksen, Jens Henrik Sahl

1989-01-01

, whereas the difference was very sensitive to even small changes in forearm blood flow within the physiological range. For measurement of renal plasma clearance it is recommended to use one long period: from the time of injection until 300 min p.i. or longer. If the clearance period is too short, the use...... introduced in the measurement of renal plasma clearance and total plasma clearance by using venous blood samples instead of arterial. In 13 patients with GFR ranging from 29 to 150 ml min-1, Ca was higher than Cv immediately after the injection. After mean 38 min (range 12-82 min) the two curves crossed...... of venous samples will overestimate the true renal clearance. Plasma clearance determined by venous and arterial blood samples does not differ significantly as long as the concentration is followed from the time of injection and a long period is applied. When simplified plasma clearance techniques are used...
Mathematical Modelling of Fluid Flow in Cone and Cavitation Formation

Directory of Open Access Journals (Sweden)

Milada KOZUBKOVÁ

2011-06-01

Full Text Available Problem of cavitation is the undesirable phenomena occuring in the fluid flow in many hydraulic application (pumps, turbines, valves, etc.. Therefore this is in the focus of interest using experimental and mathematical methods. Based on cavitation modelling in Laval nozzle results and experience [1], [2], [4], following problem described as the water flow at the outlet from turbine blade wheel was solved. Primarily the problem is simplified into modelling of water flow in cone. Profiles of axial, radial and tangential velocity are defined on inlet zone. The value of pressure is defined on the outlet. Boundary conditions were defined by main investigator of the grant project – Energy Institute, Victor Kaplan’s Department of Fluid Engineering, Faculty of Mechanical Engineering, Brno University of Technology. The value of air volume was insignificant. Cavitation was solved by Singhal model of cavitation.
New linear theory of hydrodynamic instability of the Hagen-Poiseuille flow and the blood swirling flows formation

Directory of Open Access Journals (Sweden)

Sergey G. Chefranov

2012-11-01

Full Text Available Aims This paper deals with solving of a century-old paradox of linear stability for the Hagen-Poiseuille flow. A new mechanism of dissipative hydrodynamic instability has been established herein, and a basis for the forming of helical structural organization of bloodstream and respective energy effectiveness of the cardiovascular system functioning has been defined by the authors. Materials and methods Theory of hydrodynamic instability, Galerkin’s approximation. Results A new condition Re > Reth-min ≈ 124 of linear (exponential instability of the Hagen-Poisseuille (HP flow with respect to extremely small by magnitude axially-symmetric disturbances of the tangential component of the velocity field is obtained. The disturbances necessarily shall have quasi-periodic longitudinal variability along the pipe axis that corresponds to the observed data. Conclusion We show that the obtained estimate of value of Reth-min corresponds to the condition of independence of the main result (on the linear instability of the HP flow when Re > Reth-min from the procedure of averaging used in the Galerkin approximation. Thus, we obtain the possible natural mechanism for the blood swirling flows formations observed in the aorta and the large blood vessels.
A study of swirl flow in draft tubes

Energy Technology Data Exchange (ETDEWEB)

Dahlhaug, Ole Gunnar

1997-12-31

This thesis presents measurements performed inside conical diffuser and bend, draft tubes of model hydro turbines, and draft tube of a prototype hydro turbine. Experimental results for swirling flow in conical diffuser and bend are presented in three different geometries. The axial velocity decreases at the centre of the tube at high swirl numbers because of an axial pressure gradient set up by the downstream frictional damping of the tangential velocities and the pressure increase downstream of the diffuser. Analytical models of the tangential velocity profiles are found and the radial pressure distribution calculated. Good correlation to the measured pressure distribution was achieved. Diffuser efficiency was calculated based on the equations for velocity and pressure profiles, which gave a qualified estimate of the diffuser hydraulic performance. The calculation shows that the bend reduces the efficiency by more than 30%. For a straight tube followed by a diffuser, numerical calculations were done, using K{epsilon}, RNG and RSM turbulence models for all measured swirl numbers. The K{epsilon} model gave best results for the forced vortex profile at low swirl numbers, while the RSM model gave best results at high swirl number. The turbulent kinetic energy at high swirl numbers gave the largest difference between the calculated and the measured values. Measurements on draft tubes in model turbines show the importance of good draft tube design. Prototype measurements on a Francis turbine show how the outlet draft tube flow should be measured for prototype draft tube evaluation. 54 refs., 118 figs., 2 tabs.
A study of swirl flow in draft tubes

Energy Technology Data Exchange (ETDEWEB)

Dahlhaug, Ole Gunnar

1998-12-31

This thesis presents measurements performed inside conical diffuser and bend, draft tubes of model hydro turbines, and draft tube of a prototype hydro turbine. Experimental results for swirling flow in conical diffuser and bend are presented in three different geometries. The axial velocity decreases at the centre of the tube at high swirl numbers because of an axial pressure gradient set up by the downstream frictional damping of the tangential velocities and the pressure increase downstream of the diffuser. Analytical models of the tangential velocity profiles are found and the radial pressure distribution calculated. Good correlation to the measured pressure distribution was achieved. Diffuser efficiency was calculated based on the equations for velocity and pressure profiles, which gave a qualified estimate of the diffuser hydraulic performance. The calculation shows that the bend reduces the efficiency by more than 30%. For a straight tube followed by a diffuser, numerical calculations were done, using K{epsilon}, RNG and RSM turbulence models for all measured swirl numbers. The K{epsilon} model gave best results for the forced vortex profile at low swirl numbers, while the RSM model gave best results at high swirl number. The turbulent kinetic energy at high swirl numbers gave the largest difference between the calculated and the measured values. Measurements on draft tubes in model turbines show the importance of good draft tube design. Prototype measurements on a Francis turbine show how the outlet draft tube flow should be measured for prototype draft tube evaluation. 54 refs., 118 figs., 2 tabs.
Speciation of mercury in fish samples by flow injection catalytic cold vapour atomic absorption spectrometry

International Nuclear Information System (INIS)

Zhang Yanlin; Adeloju, Samuel B.

2012-01-01

Highlights: ► Successful speciation of inorganic and organic Hg with Fe 3+ , Cu 2+ and thiourea as catalysts. ► Best sensitivity enhancement and similar sensitivity for MeHg and Hg 2+ with Fe 3+ . ► Successful use of Hg 2+ as the primary standard for quantification of inorganic and total-Hg. ► Quantitative extraction of Hg and MeHg with 2 M HCl which contained thiourea. ► Integration with FIA for rapid analysis with a sample throughput of 180 h −1 . - Abstract: A rapid flow injection catalytic cold vapour atomic absorption spectrometric (FI-CCV-AAS) method is described for speciation and determination of mercury in biological samples. Varying concentrations of NaBH 4 were employed for mercury vapour generation from inorganic and mixture of inorganic and organic (total) Hg. The presence of Fe 3+ , Cu 2+ and thiourea had catalytic effect on mercury vapour generation from methylmercury (MeHg) and, when together, Cu 2+ and thiourea had synergistic catalytic effect on the vapour generation. Of the two metal ions, Fe 3+ gave the best sensitivity enhancement, achieving the same sensitivity for MeHg and inorganic Hg 2+ . Due to similarity of resulting sensitivity, Hg 2+ was used successfully as a primary standard for quantification of inorganic and total Hg. The catalysis was homogeneous in nature, and it was assumed that the breaking of the C-Hg bond was facilitated by the delocalization of the 5d electron pairs in Hg atom. The extraction of MeHg and inorganic mercury (In-Hg) in fish samples were achieved quantitatively with hydrochloric acid in the presence of thiourea and determined by FI-CCV-AAS. The application of the method to the quantification of mercury species in a fish liver reference material DOLT-4 gave 91.5% and 102.3% recoveries for total and methyl mercury, respectively. The use of flow injection enabled rapid analysis with a sample throughput of 180 h −1 .
Review of recent applications of flow injection spectrophotometry to pharmaceutical analysis

International Nuclear Information System (INIS)

Tzanavaras, Paraskevas D.; Themelis, Demetrius G.

2007-01-01

Pharmaceutical analysis is one of the most important fields in analytical chemistry. The discovery of new drugs and the on-going update of international regulations for the safety and efficacy of pharmaceutical formulations demand the continuous development of new analytical methods. Inevitably, automation plays an important role, especially when a lot of samples have to be analyzed in the minimum of time. The present study reviews the applications of flow injection (FI) spectrophotometry to the determination of active pharmaceutical ingredients (APIs) in their respective formulations. However, the topic covered in this study is important not only to pharmaceutical analytical scientists. The principles, figures of merit and 'chemistry' of the presented methods can be of interest to bio-analytical and clinical chemists as well for the analysis of biological samples, to environmental analysts that study the up-to-date demand of the determination of the fate of pharmaceuticals in the environment and even to toxicologists and forensic scientists. This review covers scientific contributions published later than 2000. A variety of FI procedures based on homogeneous (direct UV measurements, colour-forming reactions, metal-drug interactions) and heterogeneous (optical sensors and solid-phase reactors) systems are discussed. A third section covers on-line sample pretreatment (solid-phase extraction, liquid-liquid extraction, on-line digestion, etc.)
Prediction of Gas Injection Performance for Heterogeneous Reservoirs

Energy Technology Data Exchange (ETDEWEB)

Blunt, Martin J.; Orr, Franklin M.

1999-05-17

This report describes research carried out in the Department of Petroleum Engineering at Stanford University from September 1997 - September 1998 under the second year of a three-year grant from the Department of Energy on the "Prediction of Gas Injection Performance for Heterogeneous Reservoirs." The research effort is an integrated study of the factors affecting gas injection, from the pore scale to the field scale, and involves theoretical analysis, laboratory experiments, and numerical simulation. The original proposal described research in four areas: (1) Pore scale modeling of three phase flow in porous media; (2) Laboratory experiments and analysis of factors influencing gas injection performance at the core scale with an emphasis on the fundamentals of three phase flow; (3) Benchmark simulations of gas injection at the field scale; and (4) Development of streamline-based reservoir simulator. Each state of the research is planned to provide input and insight into the next stage, such that at the end we should have an integrated understanding of the key factors affecting field scale displacements.
Modeling and design of a combined transverse and axial flow threshing unit for rice harvesters

Directory of Open Access Journals (Sweden)

Zhong Tang

2014-11-01

Full Text Available The thorough investigation of both grain threshing and grain separating processes is a crucial consideration for effective structural design and variable optimization of the tangential flow threshing cylinder and longitudinal axial flow threshing cylinder composite units (TLFC unit of small and medium-sized (SME combine harvesters. The objective of this paper was to obtain the structural variables of a TLFC unit by theoretical modeling and experimentation on a tangential flow threshing cylinder unit (TFC unit and longitudinal axial flow threshing cylinder unit (LFC unit. Threshing and separation equations for five types of threshing teeth (knife bar, trapezoidal tooth, spike tooth, rasp bar, and rectangular bar, were obtained using probability theory. Results demonstrate that the threshing and separation capacity of the knife bar TFC unit was stronger than the other threshing teeth. The length of the LFC unit was divided into four sections, with helical blades on the first section (0-0.17 m, the spike tooth on the second section (0.17-1.48 m, the trapezoidal tooth on the third section (1.48-2.91 m, and the discharge plate on the fourth section (2.91-3.35 m. Test results showed an un-threshed grain rate of 0.243%, un-separated grain rate of 0.346%, and broken grain rate of 0.184%. Evidenced by these results, threshing and separation performance is significantly improved by analyzing and optimizing the structure and variables of a TLFC unit. The results of this research can be used to successfully design the TLFC unit of small and medium-sized (SME combine harvesters.
Performance Verification for Safety Injection Tank with Fluidic Device

International Nuclear Information System (INIS)

Yune, Seok Jeong; Kim, Da Yong

2014-01-01

In LBLOCA, the SITs of a conventional nuclear power plant deliver excessive cooling water to the reactor vessel causing the water to flow into the containment atmosphere. In an effort to make it more efficient, Fluidic Device (FD) is installed inside a SIT of Advanced Power Reactor 1400 (APR 1400). FD, a complete passive controller which doesn't require actuating power, controls injection flow rates which are susceptible to a change in the flow resistance inside a vortex chamber of FD. When SIT Emergency Core Cooling (ECC) water level is above the top of the stand pipe, the water enters the vortex chamber through both the top of the stand pipe and the control ports resulting in injection of the water at a large flow rate. When the water level drops below the top of the stand pipe, the water only enters the vortex chamber through the control ports resulting in vortex formation in the vortex chamber and a relatively small flow injection. Performance verification of SIT shall be carried out because SITs play an integral role to mitigate accidents. In this paper, the performance verification method of SIT with FD is presented. In this paper, the equations for calculation of flow resistance coefficient (K) are induced to evaluate on-site performance of APR 1400 SIT with FD. Then, the equations are applied to the performance verification of SIT with FD and good results are obtained
Active Flow Control in an Aggressive Transonic Diffuser

Science.gov (United States)

Skinner, Ryan W.; Jansen, Kenneth E.

2017-11-01

A diffuser exchanges upstream kinetic energy for higher downstream static pressure by increasing duct cross-sectional area. The resulting stream-wise and span-wise pressure gradients promote extensive separation in many diffuser configurations. The present computational work evaluates active flow control strategies for separation control in an asymmetric, aggressive diffuser of rectangular cross-section at inlet Mach 0.7 and Re 2.19M. Corner suction is used to suppress secondary flows, and steady/unsteady tangential blowing controls separation on both the single ramped face and the opposite flat face. We explore results from both Spalart-Allmaras RANS and DDES turbulence modeling frameworks; the former is found to miss key physics of the flow control mechanisms. Simulated baseline, steady, and unsteady blowing performance is validated against experimental data. Funding was provided by Northrop Grumman Corporation, and this research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357.
Numerical Investigation of the Fully-Developed Periodic Flow Field for Optimal Heat Transfer in Spirally Corrugated Tubes

DEFF Research Database (Denmark)

Hærvig, Jakob; Condra, Thomas Joseph; Sørensen, Kim

Even though the corrugated tube is a widely used technique to enhance transfer heat, the exact heat transfer enhancing mechanism remains relatively un-documented. Most studies attribute the favourable heat transfer characteristics to a swirling flow being present at higher corrugation....... In this study, a systematic approach relying on Computational Fluid Dynamics (CFD) is used to study and compare the heat transfer characteristics with the detailed flow field in the spirally corrugated tubes. By comparing the flow in 12 different spirally corrugated tubes at a fixed Reynolds number of 5000......, this study compares the flow field with the surface averaged Nusselt number to gain valuable insight into which flow phenomena causes favourable heat transfer characteristics. While the flow at low corrugations approximates the non-corrugated tube, higher corrugations of h/D creates a significant tangential...
Energy harvesting through gas dynamics in the free molecular flow regime between structured surfaces at different temperatures

DEFF Research Database (Denmark)

Baier, Tobias; Dölger, Julia; Hardt, Steffen

2014-01-01

For a gas confined between surfaces held at different temperatures the velocity distribution shows a significant deviation from the Maxwell distribution when the mean free path of the molecules is comparable to or larger than the channel dimensions. If one of the surfaces is suitably structured...... from the thermal creep flow that has gained more attention so far. This situation is studied in the limit of free-molecular flow for the case that an unstructured surface is allowed to move tangentially with respect to a structured surface. Parameter studies are conducted, and configurations...

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