Development of an analytical solution for thermal single-well injection-withdrawal tests in horizontally fractured reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, Yoojin

In this study, we have developed an analytical solution for thermal single-well injection-withdrawal tests in horizontally fractured reservoirs where fluid flow through the fracture is radial. The dimensionless forms of the governing equations and the initial and boundary conditions in the radial flow system can be written in a form identical to those in the linear flow system developed by Jung and Pruess [Jung, Y., and K. Pruess (2012), A Closed-Form Analytical Solution for Thermal Single-Well Injection-Withdrawal Tests, Water Resour. Res., 48, W03504, doi:10.1029/2011WR010979], and therefore the analytical solutions developed in Jung and Pruess (2012) can be applied to computemore » the time dependence of temperature recovery at the injection/withdrawal well in a horizontally oriented fracture with radial flow.« less

Microfluidic Device for Sequential Injection and Flushing of Solutions and its Application to Immunosensing

NASA Astrophysics Data System (ADS)

Nashida, Norihiro; Suzuki, Hiroaki

A microfluidic system with injecting and flushing functions was developed. In the system, hydrophilic flow channels have a dry-film photoresist layer which facilitates the introduction of solutions from four injection ports. The injection and flushing of solutions are controlled by valves operated by electrowetting. The valves consist of gold working electrodes in the flow channels or a through-hole in the glass substrate. Solutions can be sequentially introduced through the injection ports into a reaction chamber and flushed through a valve in the through-hole. Necessary immunoassay steps can be conducted on the chip, and a target antibody can be detected electrochemically.

Electrokinetic injection techniques in microfluidic chips.

PubMed

Fu, L M; Yang, R J; Lee, G B; Liu, H H

2002-10-01

The separation efficiency of a microfluidic chip is influenced to a significant degree by the flow field conditions within the injection microchannel. Therefore, an understanding of the physics of the flow within this channel is beneficial in the design and operation of such a system. The configuration of an injection system is determined by the volume of the sample plug that is to be delivered to the separation process. Accordingly, this paper addresses the design and testing of injection systems with a variety of configurations, including a simple cross, a double-T, and a triple-T configuration. This paper also presents the design of a unique multi-T injection configuration. Each injection system cycles through a predetermined series of steps, in which the electric field magnitude and distribution within the various channels is strictly manipulated, to effectuate a virtual valve. The uniquemulti-T configuration injection system presented within this paper has the ability to simulate the functions of the cross, double-T, and triple-T systems through appropriate manipulations of the electric field within its various channels. In other words, the proposed design successfully combines several conventional injection systems within a single microfluidic chip.

Variable volume combustor with aerodynamic fuel flanges for nozzle mounting

DOE Office of Scientific and Technical Information (OSTI.GOV)

McConnaughhay, Johnie Franklin; Keener, Christopher Paul; Johnson, Thomas Edward

2016-09-20

The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles and a fuel injection system for providing a flow of fuel to the micro-mixer fuel nozzles. The fuel injection system may include a number of support struts supporting the fuel nozzles and for providing the flow of fuel therethrough. The fuel injection system also may include a number of aerodynamic fuel flanges connecting the micro-mixer fuel nozzles and the support struts.

Hot air injection for removal of dense, non-aqueous-phase liquid contaminants from low-permeability soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Payne, F.C.

1996-08-01

The performance of soil vapor extraction systems for the recovery of volatile and semi-volatile organic compounds is potentially enhanced by the injection of heated air to increase soil temperatures. The soil temperature increase is expected to improve soil vapor extraction (SVE) performance by increasing target compound vapor pressures and by increasing soil permeability through drying. The vapor pressure increase due to temperature rise relieves the vapor pressure limit on the feasibility of soil vapor extraction. However, the system still requires an air flow through the soil system to deliver heat and to recover mobilized contaminants. Although the soil permeability canmore » be increased through drying, very low permeability soils and low permeability soils adjacent to high permeability air flow pathways will be treated slowly, if at all. AR thermal enhancement methods face this limitation. Heated air injection offers advantages relative to other thermal techniques, including low capital and operation costs. Heated air injection is at a disadvantage relative to other thermal techniques due to the low heat capacity of air. To be effective, heated air injection requires that higher air flows be established than for steam injection or radio frequency heating. Heated air injection is not economically feasible for the stratified soil system developed as a standard test for this document. This is due to the inability to restrict heated air flow to the clay stratum when a low-resistance air flow pathway is available in the adjoining sand. However, the technology should be especially attractive, both technically and economically, for low-volatile contaminant recovery from relatively homogeneous soil formations. 16 refs., 2 tabs.« less

An Ion-Selective Electrode/Flow-Injection Analysis Experiment: Determination of Potassium in Serum.

ERIC Educational Resources Information Center

Meyerhoff, Mark E.; Kovach, Paul M.

1983-01-01

Describes a low-cost, senior-level, instrumental analysis experiment in which a home-made potassium tubular flow-through electrode is constructed and incorporated into a flow injection analysis system (FIA). Also describes experiments for evaluating the electrode's response properties, examining basic FIA concepts, and determining potassium in…

Flow through electrode with automated calibration

DOEpatents

Szecsody, James E [Richland, WA; Williams, Mark D [Richland, WA; Vermeul, Vince R [Richland, WA

2002-08-20

The present invention is an improved automated flow through electrode liquid monitoring system. The automated system has a sample inlet to a sample pump, a sample outlet from the sample pump to at least one flow through electrode with a waste port. At least one computer controls the sample pump and records data from the at least one flow through electrode for a liquid sample. The improvement relies upon (a) at least one source of a calibration sample connected to (b) an injection valve connected to said sample outlet and connected to said source, said injection valve further connected to said at least one flow through electrode, wherein said injection valve is controlled by said computer to select between said liquid sample or said calibration sample. Advantages include improved accuracy because of more frequent calibrations, no additional labor for calibration, no need to remove the flow through electrode(s), and minimal interruption of sampling.

Droplet-based microfluidic flow injection system with large-scale concentration gradient by a single nanoliter-scale injection for enzyme inhibition assay.

PubMed

Cai, Long-Fei; Zhu, Ying; Du, Guan-Sheng; Fang, Qun

2012-01-03

We described a microfluidic chip-based system capable of generating droplet array with a large scale concentration gradient by coupling flow injection gradient technique with droplet-based microfluidics. Multiple modules including sample injection, sample dispersion, gradient generation, droplet formation, mixing of sample and reagents, and online reaction within the droplets were integrated into the microchip. In the system, nanoliter-scale sample solution was automatically injected into the chip under valveless flow injection analysis mode. The sample zone was first dispersed in the microchannel to form a concentration gradient along the axial direction of the microchannel and then segmented into a linear array of droplets by immiscible oil phase. With the segmentation and protection of the oil phase, the concentration gradient profile of the sample was preserved in the droplet array with high fidelity. With a single injection of 16 nL of sample solution, an array of droplets with concentration gradient spanning 3-4 orders of magnitude could be generated. The present system was applied in the enzyme inhibition assay of β-galactosidase to preliminarily demonstrate its potential in high throughput drug screening. With a single injection of 16 nL of inhibitor solution, more than 240 in-droplet enzyme inhibition reactions with different inhibitor concentrations could be performed with an analysis time of 2.5 min. Compared with multiwell plate-based screening systems, the inhibitor consumption was reduced 1000-fold. © 2011 American Chemical Society

Phase and flow behavior of mixed gas hydrate systems during gas injection

NASA Astrophysics Data System (ADS)

Darnell, K.; Flemings, P. B.; DiCarlo, D. A.

2017-12-01

We present one-dimensional, multi-phase flow model results for injections of carbon dioxide and nitrogen mixtures, or flue gas, into methane hydrate bearing reservoirs. Our flow model is coupled to a thermodynamic simulator that predicts phase stabilities as a function of composition, so multiple phases can appear, disappear, or change composition as the injection invades the reservoir. We show that the coupling of multi-phase fluid flow with phase behavior causes preferential phase fractionation in which each component flows through the system at different speeds and in different phases. We further demonstrate that phase and flow behavior within the reservoir are driven by hydrate stability of each individual component in addition to the hydrate stability of the injection composition. For example, if carbon dioxide and nitrogen are both individually hydrate stable at the reservoir P-T conditions, then any injection composition will convert all available water into hydrate and plug the reservoir. In contrast, if only carbon dioxide is hydrate stable at the reservoir P-T conditions, then nitrogen preferentially stays in the gaseous phase, while the carbon dioxide partitions into the hydrate and liquid water phases. For all injections of this type, methane originally held in hydrate is released by dissociation into the nitrogen-rich gaseous phase. The net consequence is that a gas phase composed of nitrogen and methane propagates through the reservoir in a fast-moving front. A slower-moving front lags behind where carbon dioxide and nitrogen form a mixed hydrate, but methane is absent due to dissociation-induced methane stripping from the first, fast-moving front. The entire composition path traces through the phase space as the flow develops with each front moving at different, constant velocities. This behavior is qualitatively similar to the dynamics present in enhanced oil recovery or enhanced coalbed methane recovery. These results explain why the inclusion of nitrogen in mixed gas injection into methane hydrate reservoirs has been far more successful at producing methane than pure carbon dioxide injections. These results also provide a test for the validity of equilibrium thermodynamics in transport-dominated mixed hydrate systems that can be validated by laboratory-scale flow-through experiments.

Investigation of Sustained Detonation Devices: the Pulse Detonation Engine-Crossover System and the Rotating Detonation Engine System

NASA Astrophysics Data System (ADS)

Driscoll, Robert B.

An experimental study is conducted on a Pulse Detonation Engine-Crossover System to investigate the feasibility of repeated, shock-initiated combustion and characterize the initiation performance. A PDE-crossover system can decrease deflagration-to-detonation transition length while employing a single spark source to initiate a multi-PDE system. Visualization of a transferred shock wave propagating through a clear channel reveals a complex shock train behind the leading shock. Shock wave Mach number and decay rate remains constant for varying crossover tube geometries and operational frequencies. A temperature gradient forms within the crossover tube due to forward flow of high temperature ionized gas into the crossover tube from the driver PDE and backward flow of ionized gas into the crossover tube from the driven PDE, which can cause intermittent auto-ignition of the driver PDE. Initiation performance in the driven PDE is strongly dependent on initial driven PDE skin temperature in the shock wave reflection region. An array of detonation tubes connected with crossover tubes is developed using optimized parameters and successful operation utilizing shock-initiated combustion through shock wave reflection is achieved and sustained. Finally, an air-breathing, PDE-Crossover System is developed to characterize the feasibility of shock-initiated combustion within an air-breathing pulse detonation engine. The initiation effectiveness of shock-initiated combustion is compared to spark discharge and detonation injection through a pre-detonator. In all cases, shock-initiated combustion produces improved initiation performance over spark discharge and comparable detonation transition run-up lengths relative to pre-detonator initiation. A computational study characterizes the mixing processes and injection flow field within a rotating detonation engine. Injection parameters including reactant flow rate, reactant injection area, placement of the fuel injection, and fuel injection distribution are varied to assess the impact on mixing. Decreasing reactant injection areas improves fuel penetration into the cross-flowing air stream, enhances turbulent diffusion of the fuel within the annulus, and increases local equivalence ratio and fluid mixedness. Staggering fuel injection holes produces a decrease in mixing when compared to collinear fuel injection. Finally, emulating nozzle integration by increasing annulus back-pressure increases local equivalence ratio in the injection region due to increased convection residence time.

Flow monitoring and control system for injection wells

DOEpatents

Corey, J.C.

1991-01-01

The present invention relates to a system for monitoring and controlling the rate of fluid flow from an injection well used for in-situ remediation of contaminated groundwater. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.

Performance and stability analysis of gas-injection enhanced natural circulation in heavy-liquid-metal-cooled systems

NASA Astrophysics Data System (ADS)

Yoo, Yeon-Jong

The purpose of this study is to investigate the performance and stability of the gas-injection enhanced natural circulation in heavy-liquid-metal-cooled systems. The target system is STAR-LM, which is a 400-MWt-class advanced lead-cooled fast reactor under development by Argonne National Laboratory and Oregon State University. The primary loop of STAR-LM relies on natural circulation to eliminate main circulation pumps for enhancement of passive safety. To significantly increase the natural circulation flow rate for the incorporation of potential future power uprates, the injection of noncondensable gas into the coolant above the core is envisioned ("gas lift pump"). Reliance upon gas-injection enhanced natural circulation raises the concern of flow instability due to the relatively high temperature change in the reactor core and the two-phase flow condition in the riser. For this study, the one-dimensional flow field equations were applied to each flow section and the mixture models of two-phase flow, i.e., both the homogeneous and drift-flux equilibrium models were used in the two-phase region of the riser. For the stability analysis, the linear perturbation technique based on the frequency-domain approach was used by employing the Nyquist stability criterion and a numerical root search method. It has been shown that the thermal power of the STAR-LM natural circulation system could be increased from 400 up to 1152 MW with gas injection under the limiting void fraction of 0.30 and limiting coolant velocity of 2.0 m/s from the steady-state performance analysis. As the result of the linear stability analysis, it has turned out that the STAR-LM natural circulation system would be stable even with gas injection. In addition, through the parametric study, it has been found that the thermal inertia effects of solid structures such as fuel rod and heat exchanger tube should be considered in the stability analysis model. The results of this study will be a part of the optimized stable design of the gas-injection enhanced natural circulation of STAR-LM with substantially improved power level and economical competitiveness. Furthermore, combined with the parametric study, this research could contribute a guideline for the design of other similar heavy-liquid-metal-cooled natural circulation systems with gas injection.

Analysis of the Electrohydrodynamic Flow in a Symmetric System of Electrodes by the Method of Dynamic Current-Voltage Characteristics

NASA Astrophysics Data System (ADS)

Stishkov, Yu. K.; Zakir'yanova, R. E.

2018-04-01

We have solved the problem of injection-type through electrohydrodynamic (EHD) flow in a closed channel. We have considered a model of a liquid with four types of ions. It is shown that a through EHD flow without internal vortices in the electrode gap is formed for the ratio 2 : 1 of the initial injection current from the electrodes in the channel. The structure of the flow in different parts of the channel and the integral characteristics of the flow have been analyzed. It is shown that for a quadratic function of injection at the electrodes, the current-voltage characteristic of the flow is also quadratic.

Enzymatic amplification of a flow-injected thermometric enzyme-linked immunoassay for human insulin.

PubMed

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.

Determination of chloride in admixtures and aggregates for cement by a simple flow injection potentiometric system.

PubMed

Junsomboon, Jaroon; Jakmunee, Jaroon

2008-07-15

A simple flow injection system using three 3-way solenoid valves as an electric control injection valve and with a simple home-made chloride ion selective electrode based on Ag/AgCl wire as a sensor for determination of water soluble chloride in admixtures and aggregates for cement has been developed. A liquid sample or an extract was injected into a water carrier stream which was then merged with 0.1M KNO(3) stream and flowed through a flow cell where the solution will be in contact with the sensor, producing a potential change recorded as a peak. A calibration graph in range of 10-100 mg L(-1) was obtained with a detection limit of 2 mg L(-1). Relative standard deviations for 7 replicates injecting of 20, 60 and 90 mg L(-1) chloride solutions were 1.0, 1.2 and 0.6%, respectively. Sample throughput of 60 h(-1) was achieved with the consumption of 1 mL each of electrolyte solution and water carrier. The developed method was validated by the British Standard methods.

Establishing riparian vegetation through use of a self-cleaning siphon system

Treesearch

Mark D. Ankeny; L. Bradford Sumrall; Kuo-Chin Hsu

1999-01-01

Storm water or overland flow can be captured and injected into a soil trench or infiltration gallery attached to a siphon and emplaced adjacent to a stream or arroyo bank. This injected soil water can be used by stream side vegetation for wildlife habitat, bank stabilization or other purposes. The siphon system has three hydrologically-distinct flow regimes: (1)...

Three-dimensional finite amplitude electroconvection in dielectric liquids

NASA Astrophysics Data System (ADS)

Luo, Kang; Wu, Jian; Yi, Hong-Liang; Tan, He-Ping

2018-02-01

Charge injection induced electroconvection in a dielectric liquid lying between two parallel plates is numerically simulated in three dimensions (3D) using a unified lattice Boltzmann method (LBM). Cellular flow patterns and their subcritical bifurcation phenomena of 3D electroconvection are numerically investigated for the first time. A unit conversion is also derived to connect the LBM system to the real physical system. The 3D LBM codes are validated by three carefully chosen cases and all results are found to be highly consistent with the analytical solutions or other numerical studies. For strong injection, the steady state roll, polygon, and square flow patterns are observed under different initial disturbances. Numerical results show that the hexagonal cell with the central region being empty of charge and centrally downward flow is preferred in symmetric systems under random initial disturbance. For weak injection, the numerical results show that the flow directly passes from the motionless state to turbulence once the system loses its linear stability. In addition, the numerically predicted linear and finite amplitude stability criteria of different flow patterns are discussed.

An analytical solution for modeling thermal energy transfer in a confined aquifer system

NASA Astrophysics Data System (ADS)

Shaw-Yang, Yang; Hund-der, Yeh

2008-12-01

A mathematical model is developed for simulating the thermal energy transfer in a confined aquifer with different geological properties in the underlying and overlying rocks. The solutions for temperature distributions in the aquifer, underlying rock, and overlying rock are derived by the Laplace transforms and their corresponding time-domain solutions are evaluated by the modified Crump method. Field data adopted from the literature are used as examples to demonstrate the applicability of the solutions in modeling the heat transfer in an aquifer thermal energy storage (ATES) system. The results show that the aquifer temperature increases with time, injection flow rate, and water temperature. However, the temperature decreases with increasing radial and vertical distances. The heat transfer in the rocks is slow and has an effect on the aquifer temperature only after a long period of injection time. The influence distance depends on the aquifer physical and thermal properties, injection flow rate, and injected water temperature. A larger value of thermal diffusivity or injection flow rate will result in a longer influence distance. The present solution can be used as a tool for designing the heat injection facilities for an ATES system.

Variable volume combustor with aerodynamic support struts

DOEpatents

Ostebee, Heath Michael; Johnson, Thomas Edward; Stewart, Jason Thurman; Keener, Christopher Paul

2017-03-07

The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles and a fuel injection system for providing a flow of fuel to the micro-mixer fuel nozzles. The fuel injection system may include a number of support struts supporting the fuel nozzles and providing the flow of fuel therethrough. The support struts may include an aerodynamic contoured shape so as to distribute evenly a flow of air to the micro-mixer fuel nozzles.

Chemiluminescence detection of peroxynitrite with flow injection

NASA Astrophysics Data System (ADS)

Kang, Dai; Evmiridis, Nick P.; Vlessidis, Athanasios; Zhou, Yikai

2001-09-01

Peroxynitrite is an important derivative made by nitric oxide in vivo. It can make damages in many kinds of tissue and cells. Its research value in heart disease and cancer is a very high. A sensitive, specific method for analysis of peroxynitrite is described. In this method, chemiluminescence reaction between perodynitrite and luminol was used to detect with flow injection system. The assay has a detection limit of 2 by 10-8 mol L-1, and linear range of 5 by 10-8 mol L-1 to 5 by 10-5 mol L-1. The application o f flow injection system offers the possibility to establish biosensor for real-time detection of perodynitrite.

A microfluidic flow injection system for DNA assay with fluids driven by an on-chip integrated pump based on capillary and evaporation effects.

PubMed

Xu, Zhang-Run; Zhong, Chong-Hui; Guan, Yan-Xia; Chen, Xu-Wei; Wang, Jian-Hua; Fang, Zhao-Lun

2008-10-01

A miniaturized flow injection analysis (FIA) system integrating a micropump on a microfluidic chip based on capillary and evaporation effects was developed. The pump was made by fixing a filter paper plug with a vent tube at the channel end, it requires no peripheral equipment and provides steady flow in the microl min(-1) range for FIA operation. Valve-free sample injection was achieved at nanolitre level using an array of slotted vials. The practical applicability of the system was demonstrated by DNA assay with laser-induced fluorescence (LIF) detection. A precision of 1.6% RSD (10.0 ng microl(-1), n=15) was achieved with a sampling throughput of 76 h(-1) and sample consumption of 95 nl.

Passive injection control for microfluidic systems

DOEpatents

Paul, Phillip H.; Arnold, Don W.; Neyer, David W.

2004-12-21

Apparatus for eliminating siphoning, "dead" regions, and fluid concentration gradients in microscale analytical devices. In its most basic embodiment, the present invention affords passive injection control for both electric field-driven and pressure-driven systems by providing additional fluid flow channels or auxiliary channels disposed on either side of a sample separation column. The auxiliary channels are sized such that volumetric fluid flow rate through these channels, while sufficient to move the sample away from the sample injection region in a timely fashion, is less than that through the sample separation channel or chromatograph.

Dual-phase gas-permeation flow-injection thermometric analysis for the determination of carbon dioxide.

PubMed

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.

A line source tracer test - a better method for assessing high groundwater velocity

NASA Astrophysics Data System (ADS)

Magal, E.; Weisbrod, N.; Yakirevich, A.; Kurtzman, D.; Yechieli, Y.

2009-12-01

A line source injection is suggested as an effective method for assessing groundwater velocities and flow directions in subsurface characterized by high water fluxes. Modifying the common techniques of injecting a tracer into a well was necessary after frequently-used methods of natural and forced gradient tracer tests ended with no reliable information on the local groundwater flow. In a field experiment, tracers were injected into 8-m long line injection system constructed below the water table almost perpendicular to the assumed flow direction. The injection system was divided to four separate segments (each 2 m long) enabling the injection of four different tracers along the line source. An array of five boreholes located in an area of 10x10 m downstream was used for monitoring the tracers' transport. Two dye tracers (Uranine and Na Naphthionate) were injected in a long pulse of several hours into two of the injection pipe segments and two tracers (Rhenium oxide and Gd-DTPA) were instantaneously injected to the other two segments. The tracers were detected 0.7 to 2.3 hours after injection in four of the five observation wells, located 2.3 to 10 m from the injection system, respectively. Groundwater velocities were calculated directly from the tracers' arrival times and by fitting the observed breakthrough curves to simulations with one and two dimensions analytical solutions for conservative tracer transport. The groundwater velocity was determined to be ~100 m/d. The longitudinal dispersivity value, generated from fitting the tracer breakthrough curves, was in a range of 0.2-3m. The groundwater flow direction was derived based on the arrival of the tracers and was found to be consistent with the apparent direction of the hydraulic gradient. The hydraulic conductivity derived from the groundwater velocity was ~1200 m/d, which is in the upper range of gravel sediment.

[Studies on a sequential injection renewable surface reflectance spectrophotometric system using a microchip flow cell].

PubMed

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.

Separation Control in a Multistage Compressor Using Impulsive Surface Injection

NASA Technical Reports Server (NTRS)

Wundrow, David W.; Braunscheidel, Edward P.; Culley, Dennis E.; Bright, Michelle M.

2006-01-01

Control of flow separation using impulsive surface injection is investigated within the multistage environment of a low speed axial-flow compressor. Measured wake profiles behind a set of embedded stator vanes treated with suction-surface injection indicate significant reduction in flow separation at a variety of injection-pulse repetition rates and durations. The corresponding total pressure losses across the vanes reveal a bank of repetition rates at each pulse duration where the separation control remains nearly complete. This persistence allows for demands on the injected-mass delivery system to be economized while still achieving effective flow control. The response of the stator-vane boundary layers to infrequently applied short injection pulses is described in terms of the periodic excitation of turbulent strips whose growth and propagation characteristics dictate the lower bound on the band of optimal pulse repetition rates. The eventual falloff in separation control at higher repetition rates is linked to a competition between the benefits of pulse-induced mixing and the aggravation caused by the periodic introduction of low-momentum fluid. Use of these observations for impulsive actuator design is discussed and their impact on modeling the time-average effect of impulsive surface injection for multistage steady-flow simulation is considered.

A multitracer system for multizone ventilation measurement

NASA Astrophysics Data System (ADS)

Sherman, Max

1990-09-01

Mass transfer due to pressure-driven air flow is one of the most important processes for determining both environmental quality and energy requirements in buildings. Heat, moisture, and contaminants are all transported by air movement between indoors and outdoors as well as between different zones within a building. Measurement of these air flows is critical to understanding the performance of buildings. Virtually all measurements of ventilation are made using the dilution of a tracer gas. The vast majority of such measurements have been made in a single zone, using a single tracer gas. For the past several years LBL has been developing the MultiTracer Measurement System (MTMS) to provide full multizone air flow information in an accurate, real-time manner. MTMS is based on a quadrupole mass spectrometer to provide high-speed concentration analysis of multiple tracer gases in the (low) ppm level that are injected into multiple zones using mass-flow controllers. The measurement and injection system is controlled by a PC and can measure all concentrations in all zones (and adjust the injected tracer flows) within 2 min and can operate unattended for weeks. The resulting injection rate and concentration data can be analyzed to infer the bulk air movement between zones. The system also measures related quantities such as weather and zonal temperature to assist in the data interpretation. Using MTMS, field measurements have been made for the past two years.

Engine with hydraulic fuel injection and ABS circuit using a single high pressure pump

DOEpatents

Bartley, Bradley E.; Blass, James R.; Gibson, Dennis H.

2001-01-01

An engine system comprises a hydraulically actuated fuel injection system and an ABS circuit connected via a fluid flow passage that provides hydraulic fluid to both the fuel injection system and to the ABS circuit. The hydraulically actuated system includes a high pressure pump. The fluid control passage is in fluid communication with an outlet from the high pressure pump.

The efficacy of IntraFlow intraosseous injection as a primary anesthesia technique.

PubMed

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.

Flow-injection system for automated dissolution testing of isoniazid tablets with chemiluminescence detection.

PubMed

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.

Determination of mercury by multisyringe flow injection system with cold-vapor atomic absorption spectrometry.

PubMed

Leal, L O; Elsholz, O; Forteza, R; Cerdà, V

2006-07-28

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% SnCl2 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 (3sigma(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.

Integration of a Capacitive EIS Sensor into a FIA System for pH and Penicillin Determination

PubMed Central

Rolka, David; Poghossian, Arshak; Schöning, Michael J.

2004-01-01

A field-effect based capacitive EIS (electrolyte-insulator-semiconductor) sensor with a p-Si-SiO2-Ta2O5 structure has been successfully integrated into a commercial FIA (flow-injection analysis) system and system performances have been proven and optimised for pH and penicillin detection. A flow-through cell was designed taking into account the requirement of a variable internal volume (from 12 μl up to 48 μl) as well as an easy replacement of the EIS sensor. FIA parameters (sample volume, flow rate, distance between the injection valve and the EIS sensor) have been optimised in terms of high sensitivity and reproducibility as well as a minimum dispersion of the injected sample zone. An acceptable compromise between different FIA parameters has been found. For the cell design used in this study, best results have been achieved with a flow rate of 1.4 ml/min, distance between the injection valve and the EIS sensor of 6.5 cm, probe volume of 0.75 ml, cell internal volume of 12 μl. A sample throughput of at least 15 samples/h was typically obtained.

Calculation method of water injection forward modeling and inversion process in oilfield water injection network

NASA Astrophysics Data System (ADS)

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.

Steroid intracochlear distribution differs by administration method: Systemic versus intratympanic injection.

PubMed

Lee, Jong Joo; Jang, Jeong Hun; Choo, Oak-Sung; Lim, Hye Jin; Choung, Yun-Hoon

2018-01-01

Steroids have been widely used to treat inner-ear diseases such as sudden sensorineural hearing loss, tinnitus, and Meniere's disease. They can be given via either systemic or intratympanic (IT) injection. The purpose of the present study was to explore differences in intracochlear steroid distribution by the administration method employed (systemic vs. IT injection). Animal study. Twenty-three Sprague-Dawley rats were given fluorescein isothiocyanate-labeled dexamethasone (FITC-DEX) three times (on successive days) via intraperitoneal (IP) or IT injection. Cochlear uptake of FITC-DEX was evaluated via immunohistochemistry and flow cytometry at 6 hours, and 3 and 7 days after the final injection. FITC-DEX uptake was evident in spiral ganglion cells (SGs), the organ of Corti (OC), and the lateral walls (LWs), the basal turns of which were stained relatively prominently in both groups. Animals receiving IP injections exhibited higher FITC-DEX uptakes by the SGs and OC, whereas IT injection triggered higher-level FITC-DEX accumulation by the OC and LWs. Flow cytometry revealed that intracochlear FITC-DEX uptake by IT-injected animals was higher and more prolonged than in animals subjected to IP injections. We thus describe differences in cochlear steroid distributions after systemic and IT injections. This finding could help our understanding of the pharmacokinetics of steroids in the cochlea. NA. Laryngoscope, 128:189-194, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Spark gap switch with spiral gas flow

DOEpatents

Brucker, John P.

1989-01-01

A spark gap switch having a contaminate removal system using an injected gas. An annular plate concentric with an electrode of the switch defines flow paths for the injected gas which form a strong spiral flow of the gas in the housing which is effective to remove contaminates from the switch surfaces. The gas along with the contaminates is exhausted from the housing through one of the ends of the switch.

Bubble Generation in a Continuous Liquid Flow Under Reduced Gravity Conditions

NASA Technical Reports Server (NTRS)

Pais, Salvatore Cezar

1999-01-01

The present work reports a study of bubble generation under reduced gravity conditions for both co-flow and cross-flow configurations. Experiments were performed aboard the DC-9 Reduced Gravity Aircraft at NASA Glenn Research Center, using an air-water system. Three different flow tube diameters were used: 1.27, 1.9, and 2.54 cm. Two different ratios of air injection nozzle to tube diameters were considered: 0.1 and 0.2. Gas and liquid volumetric flow rates were varied from 10 to 200 ml/s. It was experimentally observed that with increasing superficial liquid velocity, the bubbles generated decreased in size. The bubble diameter was shown to increase with increasing air injection nozzle diameters. As the tube diameter was increased, the size of the detached bubbles increased. Likewise, as the superficial liquid velocity was increased, the frequency of bubble formation increased and thus the time to detach forming bubbles decreased. Independent of the flow configuration (for either single nozzle or multiple nozzle gas injection), void fraction and hence flow regime transition can be controlled in a somewhat precise manner by solely varying the gas and liquid volumetric flow rates. On the other hand, it is observed that uniformity of bubble size can be controlled more accurately by using single nozzle gas injection than by using multiple port injection, since this latter system gives rise to unpredictable coalescence of adjacent bubbles. A theoretical model, based on an overall force balance, is employed to study single bubble generation in the dynamic and bubbly flow regime. Under conditions of reduced gravity, the gas momentum flux enhances bubble detachment; however, the surface tension forces at the nozzle tip inhibits bubble detachment. Liquid drag and inertia can act either as attaching or detaching force, depending on the relative velocity of the bubble with respect to the surrounding liquid. Predictions of the theoretical model compare well with performed experiments. However, at higher superficial,liquid velocities, the bubble neck length begins to significantly deviate from the value of the air injection nozzle diameter and thus the theory no longer predicts the experiment behavior. Effects of fluid properties, injection geometry and flow conditions on generated bubble size are investigated using the theoretical model. It is shown that bubble diameter is larger in a reduced gravity environment than in a normal gravity environment at similar flow condition and flow geometry.

Assessment of electrical conductivity as a surrogate measurement for water samples in a tracer injection experiment

USDA-ARS?s Scientific Manuscript database

The transport behavior of solutes in streams depends on chemical, physical, biological, and hydrodynamic processes. Although it is a very complex system, it is known that this behavior is greatly influenced by surface and subsurface flows. For this reason, tracer injection in the water flows is one ...

Fuel injection and mixing systems and methods of using the same

DOEpatents

Mao, Chien-Pei; Short, John

2010-08-03

A fuel injection and mixing system is provided. The system includes an injector body having a fuel inlet and a fuel outlet, and defines a fuel flow path between the inlet and outlet. The fuel flow path may include a generally helical flow passage having an inlet end portion disposed proximate the fuel inlet of the injector body. The flow path also may include an expansion chamber downstream from and in fluid communication with the helical flow passage, as well as a fuel delivery device in fluid communication with the expansion chamber for delivering fuel. Heating means is also provided in thermal communication with the injector body. The heating means may be adapted and configured for maintaining the injector body at a predetermined temperature to heat fuel traversing the flow path. A method of preheating and delivering fuel is also provided.

Fluid flow characteristics during polymer flooding

NASA Astrophysics Data System (ADS)

Yao, S. L.; Dou, H. E.; Wu, M.; Zhang, H. J.

2018-05-01

At present the main problems of polymer flooding is the high injection pressure which could not guarantee the later injection. In this paper the analyses of polymer’s physical properties and its solution’s variable movement characteristics in porous media reveal the inevitable trend of decrease in injection capacity and liquid production due to the increase of fluid viscosity and flow rate with more flow resistance. The injection rate makes the primary contribution to the active viscosity of the polymer solution in porous media. The higher injection rate, the greater shearing degradation and the more the viscosity loss. Besides the quantitative variation, the rate also changes qualitatively as that the injection rate demonstrates composite change of injection intensity and density. Due to the different adjustment function of the polymer solution on its injection profile, there should be different adjustment model of rates in such stages. Here in combination of the on-site recognitions, several conclusions and recommendations are made based on the study of the injection pattern adjustment during polymer flooding to improve the pressure distribution system, which would be a meaningful reference for extensive polymer flooding in the petroleum industry.

Multiplexed detection of nitrate and nitrite for capillary electrophoresis with an automated device for high injection efficiency.

PubMed

Gao, Leyi; Patterson, Eric E; Shippy, Scott A

2006-02-01

A simple automated nanoliter scale injection device which allows for reproducible 5 nL sample injections from samples with a volume of <1 microL is successfully used for conventional capillary electrophoresis (CE) and Hadamard transform (HT) CE detection. Two standard fused silica capillaries are assembled axially through the device to function as an injection and a separation capillary. Sample solution is supplied to the injection capillary using pressure controlled with a solenoid valve. Buffer solution flows gravimetrically by the junction of the injection and separation capillaries and is also gated with a solenoid valve. Plugs of sample are pushed into the space between the injection and separation capillaries for electrokinectic injection. To evaluate the performance of the injection device, several optimizations are performed including the influence of flow rates, the injected sample volume and the control of the buffer transverse flow on the overall sensitivity. The system was then applied to HT-CE-UV detection for the signal-to-noise ratio (S/N) improvement of the nitric oxide (NO) metabolites, nitrite and nitrate. In addition, signal averaging was performed to explore the possibility of greater sensitivity enhancements compared to single injections.

Polymeric microchip for the simultaneous determination of anions and cations by hydrodynamic injection using a dual-channel sequential injection microchip electrophoresis system.

PubMed

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.

COUPLING THE ALKALINE-SURFACTANT-POLYMER TECHNOLOGY AND THE GELATION TECHNOLOGY TO MAXIMIZE OIL PRODUCTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malcolm Pitts; Jie Qi; Dan Wilson

2005-04-01

Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A priormore » fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Chromium acetate-xanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent alkaline-surfactant-polymer injected solution were observed. Aluminum citrate-polyacrylamide, resorcinol-formaldehyde, and the silicate-polyacrylamide gel systems did not produce significant incremental oil in linear corefloods. Both flowing and rigid flowing chromium acetate-polyacrylamide gels and the xanthan gum-chromium acetate gel system produced incremental oil with the rigid flowing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. None of the gels tested appeared to alter alkaline-surfactant-polymer solution oil recovery. Total waterflood plus chemical flood oil recovery sequence recoveries were all similar.« less

Passive safety injection system using borated water

DOEpatents

Conway, Lawrence E.; Schulz, Terry L.

1993-01-01

A passive safety injection system relies on differences in water density to induce natural circulatory flow patterns which help maintain prescribed concentrations of boric acid in borated water, and prevents boron from accumulating in the reactor vessel and possibly preventing heat transfer.

A Customizable Flow Injection System for Automated, High Throughput, and Time Sensitive Ion Mobility Spectrometry and Mass Spectrometry Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orton, Daniel J.; Tfaily, Malak M.; Moore, Ronald J.

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, lowmore » 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.« less

Bubble Generation in a Flowing Liquid Medium and Resulting Two-Phase Flow in Microgravity

NASA Technical Reports Server (NTRS)

Pais, S. C.; Kamotani, Y.; Bhunia, A.; Ostrach, S.

1999-01-01

The present investigation reports a study of bubble generation under reduced gravity conditions, using both a co-flow and a cross-flow configuration. This study may be used in the conceptual design of a space-based thermal management system. Ensuing two-phase flow void fraction can be accurately monitored using a single nozzle gas injection system within a continuous liquid flow conduit, as utilized in the present investigation. Accurate monitoring of void fraction leads to precise control of heat and mass transfer coefficients related to a thermal management system; hence providing an efficient and highly effective means of removing heat aboard spacecraft or space stations. Our experiments are performed in parabolic flight aboard the modified DC-9 Reduced Gravity Research Aircraft at NASA Lewis Research Center, using an air-water system. For the purpose of bubble dispersion in a flowing liquid, we use both a co-flow and a cross-flow configuration. In the co-flow geometry, air is introduced through a nozzle in the same direction with the liquid flow. On the other hand, in the cross-flow configuration, air is injected perpendicular to the direction of water flow, via a nozzle protruding inside the two-phase flow conduit. Three different flow conduit (pipe) diameters are used, namely, 1.27 cm, 1.9 cm and 2.54 cm. Two different ratios of nozzle to pipe diameter (D(sub N))sup * are considered, namely (D(sub N))sup * = 0.1 and 0.2, while superficial liquid velocities are varied from 8 to 70 cm/s depending on flow conduit diameter. It is experimentally observed that by holding all other flow conditions and geometry constant, generated bubbles decrease in size with increase in superficial liquid velocity. Detached bubble diameter is shown to increase with air injection nozzle diameter. Likewise, generated bubbles grow in size with increasing pipe diameter. Along the same lines, it is shown that bubble frequency of formation increases and hence the time to detachment of a forming bubble decreases, as the superficial liquid velocity is in-creased. Furthermore, it is shown that the void fraction of the resulting two-phase flow increases with volumetric gas flow rate Q(sub d), pipe diameter and gas injection nozzle diameter, while they decrease with surrounding liquid flow. The important role played by flowing liquid in detaching bubbles in a reduced gravity environment is thus emphasized. We observe that the void fraction can be accurately controlled by using single nozzle gas injection, rather than by employing multiple port injection, since the later system gives rise to unpredictable coalescence of adjacent bubbles. It is of interest to note that empirical bubble size and corresponding void fraction are somewhat smaller for the co-flow geometry than the cross-flow configuration at similar flow conditions with similar pipe and nozzle diameters. In order to supplement the empirical data, a theoretical model is employed to study single bubble generation in the dynamic (Q(sub d) = 1 - 1000 cu cm/s) and bubbly flow regime within the framework of the co-flow configuration. This theoretical model is based on an overall force balance acting on the bubble during the two stages of generation, namely the expansion and the detachment stage. Two sets of forces, one aiding and the other inhibiting bubble detachment are identified. Under conditions of reduced gravity, gas momentum flux enhances, while the surface tension force at the air injection nozzle tip inhibits bubble detachment. In parallel, liquid drag and inertia can act as both attaching and detaching forces, depending on the relative velocity of the bubble with respect to the surrounding liquid. Predictions of the theoretical model compare well with our experimental results. However, at higher superficial liquid velocities, as the bubble loses its spherical form, empirical bubble size no longer matches the theoretical predictions. In summary, we have developed a combined experimental and theoretical work, which describes the complex process of bubble generation and resulting two-phase flow in a microgravity environment. Results of the present study can be used in a wide range of space-based applications, such as thermal energy and power generation, propulsion, cryogenic storage and long duration life support systems, necessary for programs such as NASA's Human Exploration for the Development of Space (HEDS).

MBM fuel feeding system design and evaluation for FBG pilot plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, William A., E-mail: bill.campbell@usask.ca; Fonstad, Terry; Pugsley, Todd

2012-06-15

Highlights: Black-Right-Pointing-Pointer A 1-5 g/s fuel feeding system for pilot scale FBG was designed, built and tested. Black-Right-Pointing-Pointer Multiple conveying stages improve pressure balancing, flow control and stability. Black-Right-Pointing-Pointer Secondary conveyor stage reduced output irregularity from 47% to 15%. Black-Right-Pointing-Pointer Pneumatic air sparging effective in dealing with poor flow ability of MBM powder. Black-Right-Pointing-Pointer Pneumatic injection port plugs with char at gasification temperature of 850 Degree-Sign C. - Abstract: A biomass fuel feeding system has been designed, constructed and evaluated for a fluidized bed gasifier (FBG) pilot plant at the University of Saskatchewan (Saskatoon, SK, Canada). The system was designedmore » for meat and bone meal (MBM) to be injected into the gasifier at a mass flow-rate range of 1-5 g/s. The designed system consists of two stages of screw conveyors, including a metering stage which controlled the flow-rate of fuel, a rotary airlock and an injection conveyor stage, which delivered that fuel at a consistent rate to the FBG. The rotary airlock which was placed between these conveyors, proved unable to maintain a pressure seal, thus the entire conveying system was sealed and pressurized. A pneumatic injection nozzle was also fabricated, tested and fitted to the end of the injection conveyor for direct injection and dispersal into the fluidized bed. The 150 mm metering screw conveyor was shown to effectively control the mass output rate of the system, across a fuel output range of 1-25 g/s, while the addition of the 50 mm injection screw conveyor reduced the irregularity (error) of the system output rate from 47% to 15%. Although material plugging was found to be an issue in the inlet hopper to the injection conveyor, the addition of air sparging ports and a system to pulse air into those ports was found to successfully eliminate this issue. The addition of the pneumatic injection nozzle reduced the output irregularity further to 13%, with an air supply of 50 slpm as the minimum air supply to drive this injector. After commissioning of this final system to the FBG reactor, the injection nozzle was found to plug with char however, and was subsequently removed from the system. Final operation of the reactor continues satisfactorily with the two screw conveyors operating at matching pressure with the fluidized bed, with the output rate of the system estimated based on system characteristic equations, and confirmed by static weight measurements made before and after testing. The error rate by this method is reported to be approximately 10%, which is slightly better than the estimated error rate of 15% for the conveyor system. The reliability of this measurement prediction method relies upon the relative consistency of the physical properties of MBM with respect to its bulk density and feeding characteristics.« less

Apparatus and method to inject a reductant into an exhaust gas feedstream

DOEpatents

Viola, Michael B [Macomb Township, MI

2009-09-22

An exhaust aftertreatment system for an internal combustion engine is provided including an apparatus and method to inject a reductant into the exhaust gas feedstream. Included is a fuel metering device adapted to inject reductant into the exhaust gas feedstream and a controllable pressure regulating device. A control module is operatively connected to the reductant metering device and the controllable pressure regulating device, and, adapted to effect flow of reductant into the exhaust gas feedstream over a controllable flow range.

Closed-Loop Control of Chemical Injection Rate for a Direct Nozzle Injection System.

PubMed

Cai, Xiang; Walgenbach, Martin; Doerpmond, Malte; Schulze Lammers, Peter; Sun, Yurui

2016-01-20

To realize site-specific and variable-rate application of agricultural pesticides, accurately metering and controlling the chemical injection rate is necessary. This study presents a prototype of a direct nozzle injection system (DNIS) by which chemical concentration transport lag was greatly reduced. In this system, a rapid-reacting solenoid valve (RRV) was utilized for injecting chemicals, driven by a pulse-width modulation (PWM) signal at 100 Hz, so with varying pulse width the chemical injection rate could be adjusted. Meanwhile, a closed-loop control strategy, proportional-integral-derivative (PID) method, was applied for metering and stabilizing the chemical injection rate. In order to measure chemical flow rates and input them into the controller as a feedback in real-time, a thermodynamic flowmeter that was independent of chemical viscosity was used. Laboratory tests were conducted to assess the performance of DNIS and PID control strategy. Due to the nonlinear input-output characteristics of the RRV, a two-phase PID control process obtained better effects as compared with single PID control strategy. Test results also indicated that the set-point chemical flow rate could be achieved within less than 4 s, and the output stability was improved compared to the case without control strategy.

Normal and reverse flow injection–spectrophotometric determination of thiamine hydrochloride in pharmaceutical preparations using diazotized metoclopramide

PubMed Central

Al Abachi, Mouayed Q.; Hadi, Hind

2012-01-01

Simple and sensitive normal and reverse flow injection methods for spectrophotometric determination of thiamine hydrochloride (THC) at the microgram level were proposed and optimized. Both methods are based on the reaction between THC and diazotized metoclopramide in alkaline medium. Beer’s law was obeyed over the range of 10–300 and 2–90 μg/mL, the limits of detection were 2.118 and 0.839 μg/mL and the sampling rates were 80 and 95 injections per hour for normal and reverse flow injection methods respectively. The application of both methods to commercially available pharmaceuticals produced acceptable results. The flow system is suitable for application in quality control processes. PMID:29403765

Simultaneous determination of choline and acetylcholine based on a trienzyme chemiluminometric biosensor in a single line flow injection system.

PubMed

Kiba, Nobutoshi; Ito, Seiji; Tachibana, Masaki; Tani, Kazue; Koizumi, Hitoshi

2003-12-01

A detector for the simultaneous determination of choline (Ch) and acetylcholine (ACh) based on a sensitive trienzyme chemiluminometric biosensor in a single line flow injection (FI) system is described. Immobilized choline oxidase (ChOx), immobilized peroxidase (POx), immobilized acetylcholinesterase, and coimmobilized ChOx/POx were packed, in turn, in a transparent ETFE tube (1 mm i.d., 75 cm) and the tube was placed in front of a photomultipier tube as a flow cell. Two-peak response was obtained by one injection of the sample solution. The first and second peaks were dependent on the concentrations of Ch and ACh, respectively. The influence of some experimental parameters such as flow rate, amounts of immobilized enzymes on the behavior of the sensor was studied in order to optimize the sensitivity, sample throughput and resolution. Calibration curves were linear at 1 - 1000 nM for Ch and 3 - 3000 nM for ACh. The sample throughput was 25/h without carryover. The FI system was applied to the simultaneous determination of Ch and ACh in rabbit brain tissue homogenates.

Closed Loop Active Flow Separation Detection and Control in a Multistage Compressor

NASA Technical Reports Server (NTRS)

Bright, Michelle M.; Culley, Dennis E.; Braunscheidel, Edward P.; Welch, Gerard E.

2005-01-01

Active closed loop flow control was successfully demonstrated on a full annulus of stator vanes in a low speed axial compressor. Two independent methods of detecting separated flow conditions on the vane suction surface were developed. The first technique detects changes in static pressure along the vane suction surface, while the second method monitors variation in the potential field of the downstream rotor. Both methods may feasibly be used in future engines employing embedded flow control technology. In response to the detection of separated conditions, injection along the suction surface of each vane was used. Injected mass flow on the suction surface of stator vanes is known to reduce separation and the resulting limitation on static pressure rise due to lowered diffusion in the vane passage. A control algorithm was developed which provided a proportional response of the injected mass flow to the degree of separation, thereby minimizing the performance penalty on the compressor system.

Standby cooling system for a fluidized bed boiler

DOEpatents

Crispin, Larry G.; Weitzel, Paul S.

1990-01-01

A system for protecting components including the heat exchangers of a fluidized bed boiler against thermal mismatch. The system includes an injection tank containing an emergency supply of heated and pressurized feedwater. A heater is associated with the injection tank to maintain the temperature of the feedwater in the tank at or about the same temperature as that of the feedwater in the heat exchangers. A pressurized gas is supplied to the injection tank to cause feedwater to flow from the injection tank to the heat exchangers during thermal mismatch.

Automated contrast medium monitoring system for computed tomography--Intra-institutional audit.

PubMed

Lauretti, Dario Luca; Neri, Emanuele; Faggioni, Lorenzo; Paolicchi, Fabio; Caramella, Davide; Bartolozzi, Carlo

2015-12-01

The aim of this study was to analyze the usage and the data recorded by a RIS-PACS-connected contrast medium (CM) monitoring system (Certegra(®), Bayer Healthcare, Leverkusen, Germany) over 19 months of CT activity. The system used was connected to two dual syringe power injectors (each associated with a 16-row and a high definition 64-row multidetector CT scanner, respectively), allowing to manage contrast medium injection parameters and to send and retrieve CT study-related information via RIS/PACS for any scheduled contrast-enhanced CT examination. The system can handle up to 64 variables and can be accessed via touchscreen by CT operators as well as via a web interface by registered users with three different hierarchy levels. Data related to CM injection parameters (i.e. iodine concentration, volume and flow rate of CM, iodine delivery rate and iodine dose, CM injection pressure, and volume and flow rate of saline), patient weight and height, and type of CT study over a testing period spanning from 1 June 2013 to 10 January 2015 were retrieved from the system. Technical alerts occurred for each injection event (such as system disarm due to technical failure, disarm due to operator's stop, incomplete filling of patient data fields, or excessively high injection pressure), as well as interoperability issues related to data sending and receiving to/from the RIS/PACS were also recorded. During the testing period, the CM monitoring system generated a total of 8609 reports, of which 7629 relative to successful injection events (88.6%). 331 alerts were generated, of which 40 resulted in injection interruption and 291 in CM flow rate limitation due to excessively high injection pressure (>325 psi). Average CM volume and flow rate were 93.73 ± 17.58 mL and 3.53 ± 0.89 mL/s, and contrast injection pressure ranged between 5 and 167 psi. A statistically significant correlation was found between iodine concentration and peak IDR (rs=0.2744, p<0.0001), as well as between iodine concentration and iodine dose (rs=0.3862, p<0.0001) for all CT studies. Automated contrast management systems can provide a full report of contrast use with the possibility to systematically compare different contrast injection protocols, minimize errors, and optimize organ-specific contrast enhancement for any given patient and clinical application. This can be useful to improve and harmonize the quality and consistency of contrast CT procedures within the same radiological department and across the hospital, as well as to monitor potential adverse events and overall costs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Method for inhibiting silica precipitation and scaling in geothermal flow systems

DOEpatents

Harrar, Jackson E.; Lorensen, Lyman E.; Locke, Frank E.

1982-01-01

A method for inhibiting silica scaling and precipitation in geothermal flow systems by on-line injection of low concentrations of cationic nitrogen-containing compounds, particularly polymeric imines, polymeric amines, and quaternary ammonium compounds.

Design and Testing of Trace Contaminant Injection and Monitoring Systems

NASA Technical Reports Server (NTRS)

Broerman, Craig D.; Sweterlitsch, Jeff

2009-01-01

In support of the Carbon dioxide And Moisture Removal Amine Swing-bed (CAMRAS) testing, a contaminant injection system as well as a contaminant monitoring system has been developed by the Johnson Space Center Air Revitalization Systems (JSC-ARS) team. The contaminant injection system has been designed to provide trace level concentrations of contaminants generated by humans in a closed environment during space flight missions. The contaminant injection system continuously injects contaminants from three gas cylinders, two liquid reservoirs and three permeation ovens. The contaminant monitoring system has been designed to provide real time gas analysis with accurate flow, humidity and gas concentration measurements for collection during test. The contaminant monitoring system consists of an analytical real time gas analyzer, a carbon monoxide sensor, and an analyzer for ammonia and water vapor.

Analysis of tests of subsurface injection, storage, and recovery of freshwater in the lower Floridan aquifer, Okeechobee County, Florida

USGS Publications Warehouse

Quinones-Aponte, Vicente; Kotun, Kevin; Whitley, J.F.

1996-01-01

A series of freshwater subsurface injection, storage, and recovery tests were conducted at an injection-well site near Lake Okeechobee in Okeechobee County, Florida, to assess the recoverability of injected canal water from the Lower Floridan aquifer. At the study site, the Lower Floridan aquifer is characterized as having four local, relatively independent, high-permeability flow zones (389 to 398 meters, 419 to 424 meters, 456 to 462 meters, and 472 to 476 meters below sea level). Four subsurface injection, storage, and recovery cycles were performed at the Lake Okeechobee injection-well site in which volumes of water injected ranged from about 387,275 to 1,343,675 cubic meters for all the cycles, and volumes of water recovered ranged from about 106,200 to 484,400 cubic meters for cycles 1, 2, and 3. The recovery efficiency for successive cycles 2 and 3 increased from 22 to 36 percent and is expected to continue increasing with additional cycles. A comparison of chloride concentration breakthrough curves at the deep monitor well (located about 171 meters from the injection well) for cycles 1, 4, and test no. 4 (from a previous study) revealed unexpected finings. One significant result was that the concentration asymptote, expected to be reached at concentration levels equivalent or close to the injected water concentration, was instead reached at higher concentration levels. The injection to recovery rate ratio might affect the chloride concentration breakthrough curve at the deep monitor well, which could explain this unexpected behavior. Because there are four high-permeability zones, if the rate of injection is smaller than the rate of recovery (natural artesian flow), the head differential might not be transmitted through the entire open wellbore, and injected water would probably flow only through the upper high- permeability zones. Therefore, observed chloride concentration values at the deep monitor well would be higher than the concentration of the injected water and would represent a mix of water from the different high-permeability zones. A generalized digital model was constructed to simulate the subsurface injection, storage, and recovery of freshwater in the Lower Floridan aquifer at the Lake Okeechobee injection-well site. The model was constructed using a modified version of the Saturated-Unsaturated TRAnsport code (SUTRA), which simulates variable-density advective-dispersive solute transport and variable-density ground-water flow. Satisfactory comparisons of simulated to observed dimensionless chloride concentrations for the deep monitor well were obtained when using the model during the injection and recovery phases of cycle 1, but not for the injection well during the recovery phase of cycle 1 even after several attempts. This precluded the determination of the recovery efficiency values by using the model. The unsatisfactory comparisons of simulated to observed dimensionless chloride concentrations for the injection well and failure of the model to represent the field data at this well could be due to the characteristics of the Lower Floridan aquifer (at the local scale), which is cavernous or conduit in nature. To test this possibility, Reynolds numbers were estimated at varying distances from the injection well, taking into consideration two aquifer types or conceptual systems, porous media and cavernous. For the porous media conceptual system, the Reynolds numbers were greater than 10 at distances less than 1.42 meters from the injection well. Thus, application of Darcy's law to ground-water flow might not be valid at this distance. However, at the deep monitor well (171 meters from the injection well), the Reynolds number was 0.08 which is indicative of laminar porous media flow. For the cavernous conceptual system, the Reynolds numbers were greater than 2,000 at distances less than 1,000 meters from the well. This number represents the upper limit of laminar flow, which is the fundamental assumption

Uranium droplet core nuclear rocket

NASA Technical Reports Server (NTRS)

Anghaie, Samim

1991-01-01

Uranium droplet nuclear rocket is conceptually designed to utilize the broad temperature range ofthe liquid phase of metallic uranium in droplet configuration which maximizes the energy transfer area per unit fuel volume. In a baseline system dissociated hydrogen at 100 bar is heated to 6000 K, providing 2000 second of Isp. Fission fragments and intense radian field enhance the dissociation of molecular hydrogen beyond the equilibrium thermodynamic level. Uranium droplets in the core are confined and separated by an axisymmetric vortex flow generated by high velocity tangential injection of hydrogen in the mid-core regions. Droplet uranium flow to the core is controlled and adjusted by a twin flow nozzle injection system.

Effect of Transpiration Injection on Skin Friction in an Internal Supersonic Flow

NASA Technical Reports Server (NTRS)

Castiglone, L. A.; Northam, G. B.; Baker, N. R.; Roe, L. A.

1996-01-01

An experimental program was conducted at NASA Langley Research Center that included development and evaluation of an operational facility for wall drag measurement of potential scramjet fuel injection or wall cooling configurations. The facility consisted of a supersonic tunnel, with one wall composed of a series of interchangeable aluminum plates attached to an air bearing suspension system. The system was equipped with load cells that measured drag forces of 115 psia (793 kPa). This flow field contained a train of weak, unsteady, reflecting shock waves that were produced in the Mach 2 nozzle flows, the effect of reflecting shocks (which are to be expected in scramjet combustors) in internal flows has not previously been documented.

Method for inhibiting silica precipitation and scaling in geothermal flow systems

DOEpatents

Harrar, J.E.; Lorensen, L.E.; Locke, F.E.

1980-06-13

A method for inhibiting silica scaling and precipitation in geothermal flow systems by on-line injection of low concentrations of cationic nitrogen-containing compounds, particularly polymeric imines, polymeric amines, and quaternary ammonium compounds is described.

Mixing problems in using indicators for measuring regional blood flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ushioda, E.; Nuwayhid, B.; Tabsh, K.

A basic requirement for using indicators for measuring blood flow is adequate mixing of the indicator with blood prior to sampling the site. This requirement has been met by depositing the indicator in the heart and sampling from an artery. Recently, authors have injected microspheres into veins and sampled from venous sites. The present studies were designed to investigate the mixing problems in sheep and rabbits by means of Cardio-Green and labeled microspheres. The indicators were injected at different points in the circulatory system, and blood was sampled at different levels of the venous and arterial systems. Results show themore » following: (a) When an indicator of small molecular size (Cardio-Green) is allowed to pass through the heart chambers, adequate mixing is achieved, yielding accurate and reproducible results. (b) When any indicator (Cardio-Green or microspheres) is injected into veins, and sampling is done at any point in the venous system, mixing is inadequate, yielding flow results which are inconsistent and erratic. (c) For an indicator or large molecular size (microspheres), injecting into the left side of the heart and sampling from arterial sites yield accurate and reproducible results regardless of whether blood is sampled continuously or intermittently.« less

Decompositions of injection patterns for nodal flow allocation in renewable electricity networks

NASA Astrophysics Data System (ADS)

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.

Impact of CO2 injection protocol on fluid-solid reactivity: high-pressure and temperature microfluidic experiments in limestone

NASA Astrophysics Data System (ADS)

Jimenez-Martinez, Joaquin; Porter, Mark; Carey, James; Guthrie, George; Viswanathan, Hari

2017-04-01

Geological sequestration of CO2 has been proposed in the last decades as a technology to reduce greenhouse gas emissions to the atmosphere and mitigate the global climate change. However, some questions such as the impact of the protocol of CO2 injection on the fluid-solid reactivity remain open. In our experiments, two different protocols of injection are compared at the same conditions (8.4 MPa and 45 C, and constant flow rate 0.06 ml/min): i) single phase injection, i.e., CO2-saturated brine; and ii) simultaneous injection of CO2-saturated brine and scCO2. For that purpose, we combine a unique high-pressure/temperature microfluidics experimental system, which allows reproducing geological reservoir conditions in geo-material substrates (i.e., limestone, Cisco Formation, Texas, US) and high resolution optical profilometry. Single and multiphase flow through etched fracture networks were optically recorded with a microscope, while processes of dissolution-precipitation in the etched channels were quantified by comparison of the initial and final topology of the limestone micromodels. Changes in hydraulic conductivity were quantified from pressure difference along the micromodel. The simultaneous injection of CO2-saturated brine and scCO2, reduced the brine-limestone contact area and also created a highly heterogeneous velocity field (i.e., low velocities regions or stagnation zones, and high velocity regions or preferential paths), reducing rock dissolution and enhancing calcite precipitation. The results illustrate the contrasting effects of single and multiphase flow on chemical reactivity and suggest that multiphase flow by isolating parts of the flow system can enhance CO2 mineralization.

Determination of dipyrone in pharmaceutical preparations based on the chemiluminescent reaction of the quinolinic hydrazide-H2O2-vanadium(IV) system and flow-injection analysis.

PubMed

Pradana Pérez, Juan A; Durand Alegría, Jesús S; Hernando, Pilar Fernández; Sierra, Adolfo Narros

2012-01-01

A rapid, economic and sensitive chemiluminescent method involving flow-injection analysis was developed for the determination of dipyrone in pharmaceutical preparations. The method is based on the chemiluminescent reaction between quinolinic hydrazide and hydrogen peroxide in a strongly alkaline medium, in which vanadium(IV) acts as a catalyst. Principal chemical and physical variables involved in the flow-injection system were optimized using a modified simplex method. The variations in the quantum yield observed when dipyrone was present in the reaction medium were used to determine the concentration of this compound. The proposed method requires no preconcentration steps and reliably quantifies dipyrone over the linear range 1-50 µg/mL. In addition, a sample throughput of 85 samples/h is possible. Copyright © 2011 John Wiley & Sons, Ltd.

Fuel injection and mixing systems having piezoelectric elements and methods of using the same

DOEpatents

Mao, Chien-Pei [Clive, IA; Short, John [Norwalk, IA; Klemm, Jim [Des Moines, IA; Abbott, Royce [Des Moines, IA; Overman, Nick [West Des Moines, IA; Pack, Spencer [Urbandale, IA; Winebrenner, Audra [Des Moines, IA

2011-12-13

A fuel injection and mixing system is provided that is suitable for use with various types of fuel reformers. Preferably, the system includes a piezoelectric injector for delivering atomized fuel, a gas swirler, such as a steam swirler and/or an air swirler, a mixing chamber and a flow mixing device. The system utilizes ultrasonic vibrations to achieve fuel atomization. The fuel injection and mixing system can be used with a variety of fuel reformers and fuel cells, such as SOFC fuel cells.

Online assay of bone specific alkaline phosphatase with a flow injection-bead injection system.

PubMed

Hartwell, Supaporn Kradtap; Somprayoon, Duangporn; Kongtawelert, Prachya; Ongchai, Siriwan; Arppornchayanon, Olarn; Ganranoo, Lucksagoon; Lapanantnoppakhun, Somchai; Grudpan, Kate

2007-09-26

Alkaline phosphatase (ALP) has been used as one of the biomarkers for bone resorption and liver diseases. Normally, total alkaline phosphatase is quantified along with other symptoms to determine the releasing source of the alkaline phosphatase. A semi-automated flow injection-bead injection system was proposed to conveniently and selectively assay bone alkaline phosphatase (BALP) based on its specific binding to wheat germ coated beads. Amount of BALP in serum was determined from the intensity of the yellow product produced from bound BALP on the retained beads and its substrate pNPP. The used beads were discarded and the fresh ones were introduced for the next analysis. The reaction cell was designed to be opened and closed using a computer controlled solenoid valve for a precise incubation time. The performance of the proposed system was evaluated by using it to assay BALP in human serum. The results were compared to those obtained by using a commercial ELISA kit. The system is proposed to be an easy and cost effective system for quantification of BALP as an alternative to batch wise wheat germ specific binding technique.

Method and apparatus for continuous flow injection extraction analysis

DOEpatents

Hartenstein, Steven D.; Siemer, Darryl D.

1992-01-01

A method and apparatus for a continuous flow injection batch extraction aysis system is disclosed employing extraction of a component of a first liquid into a second liquid which is a solvent for a component of the first liquid, and is immiscible with the first liquid, and for separating the first liquid from the second liquid subsequent to extraction of the component of the first liquid.

Combined Falling Drop/Open Port Sampling Interface System for Automated Flow Injection Mass Spectrometry

DOE PAGES

Van Berkel, Gary J.; Kertesz, Vilmos; Orcutt, Matt; ...

2017-11-07

The aim of this work was to demonstrate and to evaluate the analytical performance of a combined falling drop/open port sampling interface (OPSI) system as a simple noncontact, no-carryover, automated system for flow injection analysis with mass spectrometry. The falling sample drops were introduced into the OPSI using a widely available autosampler platform utilizing low cost disposable pipet tips and conventional disposable microtiter well plates. The volume of the drops that fell onto the OPSI was in the 7–15 μL range with an injected sample volume of several hundred nanoliters. Sample drop height, positioning of the internal capillary on themore » sampling end of the probe, and carrier solvent flow rate were optimized for maximum signal. Sample throughput, signal reproducibility, matrix effects, and quantitative analysis capability of the system were established using the drug molecule propranolol and its isotope labeled internal standard in water, unprocessed river water and two commercially available buffer matrices. A sample-to-sample throughput of ~45 s with a ~4.5 s base-to-base flow injection peak profile was obtained in these experiments. In addition, quantitation with minimally processed rat plasma samples was demonstrated with three different statin drugs (atorvastatin, rosuvastatin, and fluvastatin). Direct characterization capability of unprocessed samples was demonstrated by the analysis of neat vegetable oils. Employing the autosampler system for spatially resolved liquid extraction surface sampling exemplified by the analysis of propranolol and its hydroxypropranolol glucuronide phase II metabolites from a rat thin tissue section was also illustrated.« less

Combined Falling Drop/Open Port Sampling Interface System for Automated Flow Injection Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Berkel, Gary J.; Kertesz, Vilmos; Orcutt, Matt

The aim of this work was to demonstrate and to evaluate the analytical performance of a combined falling drop/open port sampling interface (OPSI) system as a simple noncontact, no-carryover, automated system for flow injection analysis with mass spectrometry. The falling sample drops were introduced into the OPSI using a widely available autosampler platform utilizing low cost disposable pipet tips and conventional disposable microtiter well plates. The volume of the drops that fell onto the OPSI was in the 7–15 μL range with an injected sample volume of several hundred nanoliters. Sample drop height, positioning of the internal capillary on themore » sampling end of the probe, and carrier solvent flow rate were optimized for maximum signal. Sample throughput, signal reproducibility, matrix effects, and quantitative analysis capability of the system were established using the drug molecule propranolol and its isotope labeled internal standard in water, unprocessed river water and two commercially available buffer matrices. A sample-to-sample throughput of ~45 s with a ~4.5 s base-to-base flow injection peak profile was obtained in these experiments. In addition, quantitation with minimally processed rat plasma samples was demonstrated with three different statin drugs (atorvastatin, rosuvastatin, and fluvastatin). Direct characterization capability of unprocessed samples was demonstrated by the analysis of neat vegetable oils. Employing the autosampler system for spatially resolved liquid extraction surface sampling exemplified by the analysis of propranolol and its hydroxypropranolol glucuronide phase II metabolites from a rat thin tissue section was also illustrated.« less

Closed-Loop Control of Chemical Injection Rate for a Direct Nozzle Injection System

PubMed Central

Cai, Xiang; Walgenbach, Martin; Doerpmond, Malte; Schulze Lammers, Peter; Sun, Yurui

2016-01-01

To realize site-specific and variable-rate application of agricultural pesticides, accurately metering and controlling the chemical injection rate is necessary. This study presents a prototype of a direct nozzle injection system (DNIS) by which chemical concentration transport lag was greatly reduced. In this system, a rapid-reacting solenoid valve (RRV) was utilized for injecting chemicals, driven by a pulse-width modulation (PWM) signal at 100 Hz, so with varying pulse width the chemical injection rate could be adjusted. Meanwhile, a closed-loop control strategy, proportional-integral-derivative (PID) method, was applied for metering and stabilizing the chemical injection rate. In order to measure chemical flow rates and input them into the controller as a feedback in real-time, a thermodynamic flowmeter that was independent of chemical viscosity was used. Laboratory tests were conducted to assess the performance of DNIS and PID control strategy. Due to the nonlinear input–output characteristics of the RRV, a two-phase PID control process obtained better effects as compared with single PID control strategy. Test results also indicated that the set-point chemical flow rate could be achieved within less than 4 s, and the output stability was improved compared to the case without control strategy. PMID:26805833

Droplet-based magnetically activated cell separation: analysis of separation efficiency based on the variation of flow-induced circulation in a pendent drop.

PubMed

Kim, Youngho; Lee, Sang Ho; Kim, Byungkyu

2009-12-01

Under the assumption that separation efficiencies are mainly affected by the velocity of flow-induced circulation due to buffer injection in a pendent drop, this paper describes an analysis of the separation efficiency of a droplet-based magnetically activated cell separation (DMACS) system. To investigate the velocity of the flow-induced circulation, we supposed that numerous flows in a pendent drop could be considered as a "theoretically normalized" flow (or conceptually normalized flow, CNF) based on the Cauchy-Goursat theorem. With the morphological characteristics (length and duration time) of a pendent drop depending on the initial volume, we obtained the velocities of the CNF. By measuring the separation efficiencies for different initial volumes and by analyzing the separation efficiency in terms of the velocity of the CNF, we found that the separation efficiencies (in the case of a low rate of buffer injection; 5 and 15 microl x min(-1)) are mainly affected by the velocity of the CNF. Moreover, we confirmed that the phenomenological features of a pendent drop cause a fluctuation of its separation efficiencies over a range of specific volumes (initial volumes ranging from 40 to 80 microl), because of the "sweeping-off" phenomenon, that is, positive cells gathered into the positive fraction are forced to move away from the magnetic side by flow-induced circulation due to buffer injection. In addition, from the variation of the duration time, that is, the interval between the beginning of injection of the buffer solution and the time at which a pendent drop detaches, it could also be confirmed that a shorter duration time leads to decrease of the number of positive cells in negative fraction regardless of the rate of buffer injection (5, 15, and 50 microl x min(-1)). Therefore, if a DMACS system is operated with a 15 microl x min(-1) buffer injection flow rate and an initial volume of 80 microl or more, we would have the best efficiency of separation in the negative fraction.

Simple flow injection colorimetric system for determination of paraquat in natural water.

PubMed

Chuntib, Prakit; Jakmunee, Jaroon

2015-11-01

A simple and low cost flow injection colorimetric system has been developed for determination of paraquat in natural water. The developed method is based on the reduction of paraquat by using sodium dithionite as a reducing agent in an alkaline medium to produce a blue free radical ion that can be detected by a simple light emitting diode-light dependent resistor (LED-LDR) colorimeter. The standard or sample solution was injected via a set of 3-way solenoid valves into a water carrier stream and flowed to merge with reagent to generate a colored product which is proportional to the concentration of paraquat ion in the solution. Under the optimum condition of the system, i.e., mixing coil length 30 cm, flow rate 2.0 mL min(-1), sample volume 100 μL, concentrations of dithionite 0.1% (w/v) and sodium hydroxide 0.06 mol L(-1), a linear calibration graph in the range of 0.2-10.0 mg L(-1) with a correlation coefficient of 0.9996, and a limit of detection of 0.15 mg L(-1) were achieved. Relative standard deviation for 9 replicate injections of 1 mg L(-1) paraquat is 3.7%. A sample throughput of 40 injections h(-1) was achieved. The limit of detection can be improved by off-line preconcentration of paraquat employing a column packed with Dowex 50WX8-100 (H) cation exchange resin and eluted with 10% (w/v) ammonium chloride in ammonium buffer solution pH 10. The eluting solution was then injected into the FI system for paraquat determination. The proposed system did not suffer from interferences of some possible ions in natural water and other herbicides. Recoveries obtained by spiking 0.5 and 5.0 mg L(-1) paraquat standard into water samples were in the range of 104-110% and 101-105%, respectively. The developed system can be conveniently applied for screening of paraquat contaminated in natural water. Copyright © 2015 Elsevier B.V. All rights reserved.

Preliminary design of an intermittent smoke flow visualization system

NASA Technical Reports Server (NTRS)

Ward, Donald T.; Myatt, James H.

1993-01-01

A prototype intermittent flow visualization system that was designed to study vortex flow field dynamics has been constructed and tested through its ground test phase. It produces discrete pulses of dense white smoke consisting of particles of terephthalic acid by the pulsing action of a fast-acting three-way valve. The trajectories of the smoke pulses can be tracked by a video imaging system without intruding in the flow around in flight. Two methods of pulsing the smoke were examined. The simplest and safest approach is to simply divert the smoke between the two outlet ports on the valve; this approach should be particularly effective if it were desired to inject smoke at two locations during the same test event. The second approach involves closing off one of the outlet ports to momentarily block the flow. The second approach requires careful control of valve dwell times to avoid excessive pressure buildup within the cartridge container. This method also increases the velocity of the smoke injected into the flow. The flow of the smoke has been blocked for periods ranging from 30 to 80 milliseconds, depending on the system volume and the length of time the valve is allowed to remain open between valve closings.

Performance comparison of supersonic ejectors with different motive gas injection schemes applicable for flowing medium gas laser

NASA Astrophysics Data System (ADS)

Singhal, G.; Subbarao, P. M. V.; Mainuddin; Tyagi, R. K.; Dawar, A. L.

2017-05-01

A class of flowing medium gas lasers with low generator pressures employ supersonic flows with low cavity pressure and are primarily categorized as high throughput systems capable of being scaled up to MW class. These include; Chemical Oxygen Iodine Laser (COIL) and Hydrogen (Deuterium) Fluoride (HF/DF). The practicability of such laser systems for various applications is enhanced by exhausting the effluents directly to ambient atmosphere. Consequently, ejector based pressure recovery forms a potent configuration for open cycle operation. Conventionally these gas laser systems require at least two ejector stages with low pressure stage being more critical, since it directly entrains the laser media, and the ensuing perturbation of cavity flow, if any, may affect laser operation. Hence, the choice of plausible motive gas injection schemes viz., peripheral or central is a fluid dynamic issue of interest, and a parametric experimental performance comparison would be beneficial. Thus, the focus is to experimentally characterize the effect of variation in motive gas supply pressure, entrainment ratio, back pressure conditions, nozzle injection position operated together with a COIL device and discern the reasons for the behavior.

Micro-flow injection system for the urinary protein assay.

PubMed

Nishihama, Syouhei; Imabayashi, Hisano; Matoba, Tomoko; Toya, Chika; Watanabe, Kosuke; Yoshizuka, Kazuharu

2008-02-15

A urinary protein assay has been investigated, employing a micro-flow injection analysis (muFIA) combined with an adsorptive separation of protein from analyte. The adsorptive separation part of protein in the artificial urine with ceramic hydroxyapatite is integrated on the muFIA chip, since the interference of other components coexisting in urine occurs in the conventional FIA system. The typical FI peak can be obtained following the adsorption-elution process of the protein prior to the detection, and the protein concentration in artificial urine can be quantitatively determined.

Variable volume combustor with center hub fuel staging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostebee, Heath Michael; McConnaughhay, Johnie Franklin; Stewart, Jason Thurman

The present application and the resultant patent provide a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles and a fuel injection system for providing a flow of fuel to the micro-mixer fuel nozzles. The fuel injection system may include a center hub for providing the flow of fuel therethrough. The center hub may include a first supply circuit for a first micro-mixer fuel nozzle and a second supply circuit for a second micro-mixer fuel nozzle.

An Investigation of Flow in Nozzle Hole of Dimethyl Ether

NASA Astrophysics Data System (ADS)

Kato, M.; Yokota, T.; Weber, J.; Gill, D.

2015-12-01

For over twenty years, DME has shown itself to be a most promising fuel for diesel combustion. DME is produced by simple synthesis of such common sources as coal, natural gas, biomass, and waste feedstock. DME is a flammable, thermally-stable liquid similar to liquefied petroleum gas (LPG) and can be handled like LPG. However, the physical properties of DME such as its low viscosity, lubricity and bulk modulus have negative effects for the fuel injection system, which have both limited the achievable injection pressures to about 500 bar and DME's introduction into the market. To overcome some of these effects, a common rail fuel injection system was adapted to operate with DME and produce injection pressures of up to 1000 bar. To understand the effect of the high injection pressure, tests were carried out using 2D optically accessed nozzles. This allowed the impact of the high vapour pressure of DME on the onset of cavitation in the nozzle hole to be assessed and improve the flow characteristics.

Transition duct with late injection in turbine system

DOEpatents

LeBegue, Jeffrey Scott; Pentecost, Ronnie Ray; Flanagan, James Scott; Kim, Won -Wook; McMahan, Kevin Weston

2015-09-15

A system for supplying an injection fluid to a combustor is disclosed. The system includes a transition duct comprising an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The passage defines a combustion chamber. The system further includes a tube providing fluid communication for the injection fluid to flow through the transition duct and into the combustion chamber.

Multipoint Fuel Injection Arrangements

NASA Technical Reports Server (NTRS)

Prociw, Lev Alexander (Inventor)

2017-01-01

A multipoint fuel injection system includes a plurality of fuel manifolds. Each manifold is in fluid communication with a plurality of injectors arranged circumferentially about a longitudinal axis for multipoint fuel injection. The injectors of separate respective manifolds are spaced radially apart from one another for separate radial staging of fuel flow to each respective manifold.

Design and cost analysis of rapid aquifer restoration systems using flow simulation and quadratic programming.

USGS Publications Warehouse

Lefkoff, L.J.; Gorelick, S.M.

1986-01-01

Detailed two-dimensional flow simulation of a complex ground-water system is combined with quadratic and linear programming to evaluate design alternatives for rapid aquifer restoration. Results show how treatment and pumping costs depend dynamically on the type of treatment process, and capacity of pumping and injection wells, and the number of wells. The design for an inexpensive treatment process minimizes pumping costs, while an expensive process results in the minimization of treatment costs. Substantial reductions in pumping costs occur with increases in injection capacity or in the number of wells. Treatment costs are reduced by expansions in pumping capacity or injecion capacity. The analysis identifies maximum pumping and injection capacities.-from Authors

Dispersion of a Nanoliter Bolus in Microfluidic Co-Flow.

PubMed

Conway, A J; Saadi, W M; Sinatra, F L; Kowalski, G; Larson, D; Fiering, J

2014-03-01

Microfluidic systems enable reactions and assays on the scale of nanoliters. However, at this scale nonuniformities in sample delivery become significant. To determine the fundamental minimum sample volume required for a particular device, a detailed understanding of mass transport is required. Co-flowing laminar streams are widely used in many devices, but typically only in the steady-state. Because establishing the co-flow steady-state consumes excess sample volume and time, there is a benefit to operating devices in the transient state, which predominates as the volume of the co-flow reactor decreases. Analysis of the co-flow transient has been neglected thus far. In this work we describe the fabrication of a pneumatically controlled microfluidic injector constructed to inject a discrete 50nL bolus into one side of a two-stream co-flow reactor. Using dye for image analysis, injections were performed at a range of flow rates from 0.5-10μL/min, and for comparison we collected the co-flow steady-state data for this range. The results of the image analysis were also compared against theory and simulations for device validation. For evaluation, we established a metric that indicates how well the mass distribution in the bolus injection approximates steady-state co-flow. Using such analysis, transient-state injections can approximate steady-state conditions within predefined errors, allowing straight forward measurements to be performed with reduced reagent consumption.

Numerical simulation of water injection into vapor-dominated reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pruess, K.

1995-01-01

Water injection into vapor-dominated reservoirs is a means of condensate disposal, as well as a reservoir management tool for enhancing energy recovery and reservoir life. We review different approaches to modeling the complex fluid and heat flow processes during injection into vapor-dominated systems. Vapor pressure lowering, grid orientation effects, and physical dispersion of injection plumes from reservoir heterogeneity are important considerations for a realistic modeling of injection effects. An example of detailed three-dimensional modeling of injection experiments at The Geysers is given.

Load flows and faults considering dc current injections

NASA Technical Reports Server (NTRS)

Kusic, G. L.; Beach, R. F.

1991-01-01

The authors present novel methods for incorporating current injection sources into dc power flow computations and determining network fault currents when electronic devices limit fault currents. Combinations of current and voltage sources into a single network are considered in a general formulation. An example of relay coordination is presented. The present study is pertinent to the development of the Space Station Freedom electrical generation, transmission, and distribution system.

System and method for treatment of a medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Surinder Prabhjot; Acharya, Harish Radhakrishna; Perry, Robert James

2017-05-23

A system and method for treatment of a medium is disclosed. The system includes a plurality of separator zones and a plurality of heat transfer zones. Each of the separator zone and the heat transfer zone among the plurality of separator zones and heat transfer zones respectively, are disposed alternatively in a flow duct. Further, each separator zone includes an injector device for injecting a sorbent into the corresponding separator zone. Within the corresponding separator zone, the injected sorbent is reacted with a gaseous medium flowing in the flow duct, so as to generate a reacted gaseous medium and amore » reacted sorbent. Further, each heat transfer zone exchanges heat between the reacted gaseous medium fed from the corresponding separator zone and a heat transfer medium.« less

Mathematical Modeling of Fluid Flow in a Water Physical Model of an Aluminum Degassing Ladle Equipped with an Impeller-Injector

NASA Astrophysics Data System (ADS)

Gómez, Eudoxio Ramos; Zenit, Roberto; Rivera, Carlos González; Trápaga, Gerardo; Ramírez-Argáez, Marco A.

2013-04-01

In this work, a 3D numerical simulation using a Euler-Euler-based model implemented into a commercial CFD code was used to simulate fluid flow and turbulence structure in a water physical model of an aluminum ladle equipped with an impeller for degassing treatment. The effect of critical process parameters such as rotor speed, gas flow rate, and the point of gas injection (conventional injection through the shaft vs a novel injection through the bottom of the ladle) on the fluid flow and vortex formation was analyzed with this model. The commercial CFD code PHOENICS 3.4 was used to solve all conservation equations governing the process for this two-phase fluid flow system. The mathematical model was reasonably well validated against experimentally measured liquid velocity and vortex sizes in a water physical model built specifically for this investigation. From the results, it was concluded that the angular speed of the impeller is the most important parameter in promoting better stirred baths and creating smaller and better distributed bubbles in the liquid. The pumping effect of the impeller is increased as the impeller rotation speed increases. Gas flow rate is detrimental to bath stirring and diminishes the pumping effect of the impeller. Finally, although the injection point was the least significant variable, it was found that the "novel" injection improves stirring in the ladle.

Flow-injection analysis of catecholamine secretion from bovine adrenal medulla cells on microbeads.

PubMed

Herrera, M; Kao, L S; Curran, D J; Westhead, E W

1985-01-01

Bovine adrenal medullary cells have been cultured on microbeads which are placed in a low-volume flow system for measurements of stimulation-response parameters. Electronically controlled stream switching allows stimulation of cells with pulse lengths from 1 s to many minutes; pulses may be repeated indefinitely. Catecholamines secreted are detected by an electrochemical detector downstream from the cells. This flow-injection analysis technique provides a new level of sensitivity and precision for measurement of kinetic parameters of secretion. A manual injection valve allows stimulation by higher levels of stimulant in the presence of constant low levels of stimulant. Such experiments show interesting differences between the effects of K+ and acetylcholine on cells partially desensitized to acetylcholine.

Effect of double air injection on performance characteristics of centrifugal compressor

NASA Astrophysics Data System (ADS)

Hirano, Toshiyuki; Takano, Mizuki; Tsujita, Hoshio

2015-02-01

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, for the suppression of surge phenomenon resulting in the extension of the stable operating range of centrifugal compressor to lower flow rate, the compressed air at the compressor exit was re-circulated and injected into the impeller inlet by using the double injection nozzle system. The experiments were performed to find out the optimum circumferential position of the second nozzle relative to the fixed first one and the optimum inner diameter of the injection nozzles, which are able to most effectively reduce the flow rate of surge inception. Moreover, in order to examine the universality of these optimum values, the experiments were carried out for two types of compressors.

Investigation of spray characteristics for flashing injection of fuels containing dissolved air and superheated fuels

NASA Technical Reports Server (NTRS)

Solomon, A. S. P.; Chen, L. D.; Faeth, G. M.

1982-01-01

The flow, atomization and spreading of flashing injector flowing liquids containing dissolved gases (jet/air) as well as superheated liquids (Freon II) were considered. The use of a two stage expansion process separated by an expansion chamber, ws found to be beneficial for flashing injection particularly for dissolved gas systems. Both locally homogeneous and separated flow models provided good predictions of injector flow properties. Conventional correlations for drop sizes from pressure atomized and airblast injectors were successfully modified, using the separated flow model to prescribe injector exit conditions, to correlate drop size measurements. Additional experimental results are provided for spray angle and combustion properties of sprays from flashing injectors.

Using a tracer technique to identify the extent of non-ideal flows in the continuous mixing of non-Newtonian fluids

NASA Astrophysics Data System (ADS)

Patel, D.; Ein-Mozaffari, F.; Mehrvar, M.

2013-05-01

The identification of non-ideal flows in a continuous-flow mixing of non-Newtonian fluids is a challenging task for various chemical industries: plastic manufacturing, water and wastewater treatment, and pulp and paper manufacturing. Non-ideal flows such as channelling, recirculation, and dead zones significantly affect the performance of continuous-flow mixing systems. Therefore, the main objective of this paper was to develop an identification protocol to measure non-ideal flows in the continuous-flow mixing system. The extent of non-ideal flows was quantified using a dynamic model that incorporated channelling, recirculation, and dead volume in the mixing vessel. To estimate the dynamic model parameters, the system was excited using a frequency-modulated random binary input by injecting the saline solution (as a tracer) into the fresh feed stream prior to being pumped into the mixing vessel. The injection of the tracer was controlled by a computer-controlled on-off solenoid valve. Using the trace technique, the extent of channelling and the effective mixed volume were successfully determined and used as mixing quality criteria. Such identification procedures can be applied at various areas of chemical engineering in order to improve the mixing quality.

A multi-commuted flow injection system with a multi-channel propulsion unit placed before detection: Spectrophotometric determination of ammonium.

PubMed

Oliveira, Sara M; Lopes, Teresa I M S; Tóth, Ildikó V; Rangel, António O S S

2007-09-26

A flow system with a multi-channel peristaltic pump placed before the solenoid valves is proposed to overcome some limitations attributed to multi-commuted flow injection systems: the negative pressure can lead to the formation of unwanted air bubbles and limits the use of devices for separation processes (gas diffusion, dialysis or ion-exchange). The proposed approach was applied to the colorimetric determination of ammonium nitrogen. In alkaline medium, ammonium is converted into ammonia, which diffuses over the membrane, causing a pH change and subsequently a colour change in the acceptor stream (bromothymol blue solution). The system allowed the re-circulation of the acceptor solution and was applied to ammonium determination in surface and tap water, providing relative standard deviations lower than 1.5%. A stopped flow approach in the acceptor stream was adopted to attain a low quantification limit (42 microgL(-1)) and a linear dynamic range of 50-1000 microgL(-1) with a determination rate of 20 h(-1).

A novel approach for determination of free fatty acids in vegetable oils by a flow injection system with manual injection.

PubMed

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 < 1%), and were rugged when the method was performed by a different 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.

AAO-CNTs electrode on microfluidic flow injection system for rapid iodide sensing.

PubMed

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.

Investigation of representing hysteresis in macroscopic models of two-phase flow in porous media using intermediate scale experimental data

NASA Astrophysics Data System (ADS)

Cihan, Abdullah; Birkholzer, Jens; Trevisan, Luca; Gonzalez-Nicolas, Ana; Illangasekare, Tissa

2017-01-01

Incorporating hysteresis into models is important to accurately capture the two phase flow behavior when porous media systems undergo cycles of drainage and imbibition such as in the cases of injection and post-injection redistribution of CO2 during geological CO2 storage (GCS). In the traditional model of two-phase flow, existing constitutive models that parameterize the hysteresis associated with these processes are generally based on the empirical relationships. This manuscript presents development and testing of mathematical hysteretic capillary pressure—saturation—relative permeability models with the objective of more accurately representing the redistribution of the fluids after injection. The constitutive models are developed by relating macroscopic variables to basic physics of two-phase capillary displacements at pore-scale and void space distribution properties. The modeling approach with the developed constitutive models with and without hysteresis as input is tested against some intermediate-scale flow cell experiments to test the ability of the models to represent movement and capillary trapping of immiscible fluids under macroscopically homogeneous and heterogeneous conditions. The hysteretic two-phase flow model predicted the overall plume migration and distribution during and post injection reasonably well and represented the postinjection behavior of the plume more accurately than the nonhysteretic models. Based on the results in this study, neglecting hysteresis in the constitutive models of the traditional two-phase flow theory can seriously overpredict or underpredict the injected fluid distribution during post-injection under both homogeneous and heterogeneous conditions, depending on the selected value of the residual saturation in the nonhysteretic models.

A flow system for the spectrophotometric determination of lead in different types of waters using ion-exchange for pre-concentration and elimination of interferences.

PubMed

Mesquita, Raquel B R; Fernandes, Sílvia M V; Rangel, António O S S

2004-02-06

A flow system for the spectrophotometric determination of lead in natural and waste waters is proposed. The determination is based on the colorimetric reaction between malachite green and iodide, followed by the formation of a ternary complex between those reagents and lead cations. The developed flow system includes a lead pre-concentration step in a column packed with a cationic resin (Chelex 100) operating in a sequential injection mode. To improve the mixture of sample and reagents, a flow injection approach was adopted for the colorimetric determination. This way a hybrid flow system, involving both sequential and flow injection concepts was designed. Another feature of the proposed system is the efficient elimination of major interferent species, such as cadmium and copper. The elimination of cadmium interference is obtained by complexing Cd(2+) with chloride and retaining the formed negatively charged complexes in an anionic resin, AG1 X-8. As for copper, with the presence of both ionic resins as well as the conditions for cadmium elimination, it no longer acts as an interferent. Different ranges of lead concentration (50-300 and 300-1000mugl(-1)) can be determined with minor changes in the controlling software, useful for application to both natural and waste waters. Therefore, a detection limit of 25mugl(-1) was achieved. Repeatability was evaluated from 10 consecutive determinations being the results better than 4%. The recoveries of lead spikes added to the samples ranged from 93 to 102%. The sampling frequency was 17 and 24 determinations per hour, for 50-300 and 300-1000mugl(-1) ranges, respectively.

Combustor assembly in a gas turbine engine

DOEpatents

Wiebe, David J; Fox, Timothy A

2015-04-28

A combustor assembly in a gas turbine engine includes a combustor device, a fuel injection system, a transition duct, and an intermediate duct. The combustor device includes a flow sleeve for receiving pressurized air and a liner surrounded by the flow sleeve. The fuel injection system provides fuel to be mixed with the pressurized air and ignited in the liner to create combustion products. The intermediate duct is disposed between the liner and the transition duct so as to define a path for the combustion products to flow from the liner to the transition duct. The intermediate duct is associated with the liner such that movement may occur therebetween, and the intermediate duct is associated with the transition duct such that movement may occur therebetween. The flow sleeve includes structure that defines an axial stop for limiting axial movement of the intermediate duct.

Application of Synthetic Jets to Reduce Stator Flow Separation in a Low Speed Axial Compressor

NASA Technical Reports Server (NTRS)

Braunscheidel, Edward P.; Culley, Dennis E.; Zaman, Khairul B.M.Q.

2008-01-01

Flow control using synthetic jet injection has been applied in a low speed axial compressor. The synthetic jets were applied from the suction surface of a stator vane via a span-wise row of slots pitched in the streamwise direction. Actuation was provided externally from acoustic drivers coupled to the vane tip via flexible tubing. The acoustic resonance characteristics of the system, and the resultant jet velocities were obtained. The effects on the separated flow field for various jet velocities and frequencies were explored. Total pressure loss reductions across the vane passage were measured. The effect of synthetic jet injection was shown to be comparable to that of pulsatory injection with mass addition for stator vanes which had separated flow. While only a weak dependence of the beneficial effect was noted based on the excitation frequency, a strong dependence on the amplitude was observed at all frequencies.

A computational investigation of fuel mixing in a hypersonic scramjet

NASA Technical Reports Server (NTRS)

Fathauer, Brett W.; Rogers, R. C.

1993-01-01

A parabolized, Navier-Stokes code, SHIP3D, is used to numerically investigate the mixing between air injection and hydrogen injection from a swept ramp injector configuration into either a mainstream low-enthalpy flow or a hypervelocity test flow. The mixing comparisons between air and hydrogen injection reveal the importance of matching injectant-to-mainstream mass flow ratios. In flows with the same injectant-to-mainstream dynamic pressure ratio, the mixing definition was altered for the air injection cases. Comparisons of the computed results indicate that the air injection cases overestimate the mixing performance associated with hydrogen injection simulation. A lifting length parameter, to account for the time a fluid particle transverses through the mixing region, is defined and used to establish a connection of injectant mixing in hypervelocity flows, based on nonreactive, low-enthalpy flows.

Capture zone of a multi-well system in bounded peninsula-shaped aquifers.

PubMed

Zarei-Doudeji, Somayeh; Samani, Nozar

2014-08-01

In this paper we present the equation of capture zone for multi-well system in peninsula-shaped confined and unconfined aquifers. The aquifer is rectangular in plan view, bounded along three sides, and extends to infinity at the fourth side. The bounding boundaries are either no-flow (impervious) or in-flow (constant head) so that aquifers with six possible boundary configurations are formed. The well system is consisted of any number of extraction or injection wells or combination of both with any flow rates. The complex velocity potential equations for such a well-aquifer system are derived to delineate the capture envelop. Solutions are provided for the aquifers with and without a uniform regional flow of any directions. The presented equations are of general character and have no limitations in terms of well numbers, positions and types, extraction/injection rate, and regional flow rate and direction. These solutions are presented in form of capture type curves which are useful tools in hands of practitioners to design in-situ groundwater remediation systems, to contain contaminant plumes, to evaluate the surface-subsurface water interaction and to verify numerical models. Copyright © 2014 Elsevier B.V. All rights reserved.

Mixing enhancement strategies and their mechanisms in supersonic flows: A brief review

NASA Astrophysics Data System (ADS)

Huang, Wei

2018-04-01

Achieving efficient fuel-air mixing is a crucial issue in the design of the scramjet engine due to the compressibility effect on the mixing shear layer growth and the stringent flow residence time limitation induced by the high-speed crossflow, and the potential solution is to enhance mixing between air and fuel by introducing of streamwise vortices in the flow field. In this survey, some mixing enhancement strategies based on the traditional transverse injection technique proposed in recent years, as well as their mixing augmentation mechanisms, were reviewed in detail, namely the pulsed transverse injection scheme, the traditional transverse injection coupled with the vortex generator, and the dual transverse injection system with a front porthole and a rear air porthole arranged in tandem. The streamwise vortices, through the large-scale stirring motion that they introduce, are responsible for the extraction of large amounts of energy from the mean flow that can be converted into turbulence, ultimately leading to increased mixing effectiveness. The streamwise vortices may be obtained by taking advantage of the shear layer between a jet and the cross stream or by employing intrusive physical devices. Finally, a promising mixing enhancement strategy in supersonic flows was proposed, and some remarks were provided.

[The action of high-molecular linear polymers on the circulatory system].

PubMed

Grigorian, S S; Sokolova, I A; Shakhnazarov, A A

1995-01-01

An analysis of the hemodynamic consequences of the injections of long linear polymers with high molecular weight is introduced. These injections lead to an increase of the cardiac output, to a decrease of the blood pressure, and hence cause a reduction of the resistance to blood flow. It follows that such kind of polymers is able to normalize hemodynamics under some pathophysiological conditions, e.g., during experimental atherosclerosis, ischemic state, hemorrhagic shock. An addition of drag-reducing polymers into the blood system is associated with a modification of the blood flow microstructure itself.

Heat Transfer Analysis for Stationary Boundary Layer Slip Flow of a Power-Law Fluid in a Darcy Porous Medium with Plate Suction/Injection

PubMed Central

Aziz, Asim; Ali, Yasir; Aziz, Taha; Siddique, J. I.

2015-01-01

In this paper, we investigate the slip effects on the boundary layer flow and heat transfer characteristics of a power-law fluid past a porous flat plate embedded in the Darcy type porous medium. The nonlinear coupled system of partial differential equations governing the flow and heat transfer of a power-law fluid is transformed into a system of nonlinear coupled ordinary differential equations by applying a suitable similarity transformation. The resulting system of ordinary differential equations is solved numerically using Matlab bvp4c solver. Numerical results are presented in the form of graphs and the effects of the power-law index, velocity and thermal slip parameters, permeability parameter, suction/injection parameter on the velocity and temperature profiles are examined. PMID:26407162

Parametric Studies of Flow Separation using Air Injection

NASA Technical Reports Server (NTRS)

Zhang, Wei

2004-01-01

Boundary Layer separation causes the airfoil to stall and therefore imposes dramatic performance degradation on the airfoil. In recent years, flow separation control has been one of the active research areas in the field of aerodynamics due to its promising performance improvements on the lifting device. These active flow separation control techniques include steady and unsteady air injection as well as suction on the airfoil surface etc. This paper will be focusing on the steady and unsteady air injection on the airfoil. Although wind tunnel experiments revealed that the performance improvements on the airfoil using injection techniques, the details of how the key variables such as air injection slot geometry and air injection angle etc impact the effectiveness of flow separation control via air injection has not been studied. A parametric study of both steady and unsteady air injection active flow control will be the main objective for this summer. For steady injection, the key variables include the slot geometry, orientation, spacing, air injection velocity as well as the injection angle. For unsteady injection, the injection frequency will also be investigated. Key metrics such as lift coefficient, drag coefficient, total pressure loss and total injection mass will be used to measure the effectiveness of the control technique. A design of experiments using the Box-Behnken Design is set up in order to determine how each of the variables affects each of the key metrics. Design of experiment is used so that the number of experimental runs will be at minimum and still be able to predict which variables are the key contributors to the responses. The experiments will then be conducted in the 1ft by 1ft wind tunnel according to the design of experiment settings. The data obtained from the experiments will be imported into JMP, statistical software, to generate sets of response surface equations which represent the statistical empirical model for each of the metrics as a function of the key variables. Next, the variables such as the slot geometry can be optimized using the build-in optimizer within JMP. Finally, a wind tunnel testing will be conducted using the optimized slot geometry and other key variables to verify the empirical statistical model. The long term goal for this effort is to assess the impacts of active flow control using air injection at system level as one of the task plan included in the NASAs URETI program with Georgia Institute of Technology.

Modeling the Impact of Fracture Growth on Fluid Displacements in Deformable Porous Media

NASA Astrophysics Data System (ADS)

Santillán, D.; Cueto-Felgueroso, L.; Juanes, R.

2015-12-01

Coupled flow and geomechanics is a critical research challenge in engineering and the geosciences. The flow of a fluid through a deformable porous media is present in manyenvironmental, industrial, and biological processes,such as the removal of pollutants from underground water bodies, enhanced geothermal systems, unconventional hydrocarbon resources or enhanced oil recovery techniques. However, the injection of a fluid can generate or propagate fractures, which are preferential flow paths. Using numerical simulation, we study the interplay between injection and rock mechanics, and elucidate fracture propagation as a function of injection rate, initial crack topology and mechanical rock properties. Finally, we discuss the role of fracture growth on fluid displacements in porous media. Figure: An example of fracture (in red) propagated in a porous media (in blue)

Waterflood control system for maximizing total oil recovery

DOEpatents

Patzek, Tadeusz Wiktor; Silin, Dimitriy Borisovic; De, Asoke Kumar

2005-06-07

A control system and method for determining optimal fluid injection pressure is based upon a model of a growing hydrofracture due to waterflood injection pressure. This model is used to develop a control system optimizing the injection pressure by using a prescribed injection goal coupled with the historical times, pressures, and volume of injected fluid at a single well. In this control method, the historical data is used to derive two major flow components: the transitional component, where cumulative injection volume is scaled as the square root of time, and a steady-state breakthrough component, which scales linearly with respect to time. These components provide diagnostic information and allow for the prevention of rapid fracture growth and associated massive water break through that is an important part of a successful waterflood, thereby extending the life of both injection and associated production wells in waterflood secondary oil recovery operations.

Waterflood control system for maximizing total oil recovery

DOEpatents

Patzek, Tadeusz Wiktor [Oakland, CA; Silin, Dimitriy Borisovich [Pleasant Hill, CA; De, Asoke Kumar [San Jose, CA

2007-07-24

A control system and method for determining optimal fluid injection pressure is based upon a model of a growing hydrofracture due to waterflood injection pressure. This model is used to develop a control system optimizing the injection pressure by using a prescribed injection goal coupled with the historical times, pressures, and volume of injected fluid at a single well. In this control method, the historical data is used to derive two major flow components: the transitional component, where cumulative injection volume is scaled as the square root of time, and a steady-state breakthrough component, which scales linearly with respect to time. These components provide diagnostic information and allow for the prevention of rapid fracture growth and associated massive water break through that is an important part of a successful waterflood, thereby extending the life of both injection and associated production wells in waterflood secondary oil recovery operations.

A dilute-and-shoot flow-injection tandem mass spectrometry method for quantification of phenobarbital in urine.

PubMed

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.

Examination of the effect of blowing on the near-surface flow structure over a dimpled surface

NASA Astrophysics Data System (ADS)

Borchetta, C. G.; Martin, A.; Bailey, S. C. C.

2018-03-01

The near surface flow over a dimpled surface with flow injection through it was documented using time-resolved particle image velocimetry. The instantaneous flow structure, time-averaged statistics, and results from snapshot proper orthogonal decomposition were used to examine the coherent structures forming near the dimpled surface. In particular, the modifications made to the flow structures by the addition of flow injection through the surface were studied. It was observed that without flow injection, inclined flow structures with alternating vorticity from neighboring dimples are generated by the dimples and advect downstream. This behavior is coupled with fluid becoming entrained inside the dimples, recirculating and ejecting away from the surface. When flow injection was introduced through the surface, the flow structures became more disorganized, but some of the features of the semi-periodic structures observed without flow injection were preserved. The structures with flow injection appear in multiple wall-normal layers, formed from vortical structures shed from upstream dimples, with a corresponding increase in the size of the advecting structures. As a result of the more complex flow field observed with flow injection, there was an increase in turbulent kinetic energy and Reynolds shear stress, with the Reynolds shear stress representing an increase in vertical transport of momentum by sweeping and ejecting motions that were not present without flow injection.

Design and performance of a new continuous-flow sample-introduction system for flame infrared-emission spectrometry: Applications in process analysis, flow injection analysis, and ion-exchange high-performance liquid chromatography.

PubMed

Lam, C K; Zhang, Y; Busch, M A; Busch, K W

1993-06-01

A new sample introduction system for the analysis of continuously flowing liquid streams by flame infrared-emission (FIRE) spectrometry has been developed. The system uses a specially designed purge cell to strip dissolved CO(2) from solution into a hydrogen gas stream that serves as the fuel for a hydrogen/air flame. Vibrationally excited CO(2) molecules present in the flame are monitored with a simple infrared filter (4.4 mum) photometer. The new system can be used to introduce analytes as a continuous liquid stream (process analysis mode) or on a discrete basis by sample injection (flow injection analysis mode). The key to the success of the method is the new purge-cell design. The small internal volume of the cell minimizes problems associated with purge-cell clean-out and produces sharp, reproducible signals. Spent analytical solution is continuously drained from the cell, making cell disconnection and cleaning between samples unnecessary. Under the conditions employed in this study, samples could be analyzed at a maximum rate of approximately 60/h. The new sample introduction system was successfully tested in both a process analysis- and a flow injection analysis mode for the determination of total inorganic carbon in Waco tap water. For the first time, flame infrared-emission spectrometry was successfully extended to non-volatile organic compounds by using chemical pretreatment with peroxydisulfate in the presence of silver ion to convert the analytes into dissolved carbon dioxide, prior to purging and detection by the FIRE radiometer. A test of the peroxydisulfate/Ag(+) reaction using six organic acids and five sugars indicated that all 11 compounds were oxidized to nearly the same extent. Finally, the new sample introduction system was used in conjunction with a simple filter FIRE radiometer as a detection system in ion-exchange high-performance liquid chromatography. Ion-exchange chromatograms are shown for two aqueous mixtures, one containing six organic acids and the second containing six mono-, di-, and trisaccharides.

Fluidic Chevrons for Jet Noise Reduction

NASA Technical Reports Server (NTRS)

Kinzie, Kevin; Henderson, Brenda; Whitmire, Julia

2004-01-01

Chevron mixing devices are used to reduce noise from commercial separate-flow turbofan engines. Mechanical chevron serrations at the nozzle trailing edge generate axial vorticity that enhances jet plume mixing and consequently reduces far-field noise. Fluidic chevrons generated with air injected near the nozzle trailing edge create a vorticity field similar to that of the mechanical chevrons and allow more flexibility in controlling acoustic and thrust performance than a passive mechanical design. In addition, the design of such a system has the future potential for actively controlling jet noise by pulsing or otherwise optimally distributing the injected air. Scale model jet noise experiments have been performed in the NASA Langley Low Speed Aeroacoustic Wind Tunnel to investigate the fluidic chevron concept. Acoustic data from different fluidic chevron designs are shown. Varying degrees of noise reduction are achieved depending on the injection pattern and injection flow conditions. CFD results were used to select design concepts that displayed axial vorticity growth similar to that associated with mechanical chevrons and qualitatively describe the air injection flow and the impact on acoustic performance.

Chitosan-guar gum-silver nanoparticles hybrid matrix with immobilized enzymes for fabrication of beta-glucan and glucose sensing photometric flow injection system.

PubMed

Bagal-Kestwal, Dipali R; Kestwal, Rakesh Mohan; Hsieh, Wen-Ting; Chiang, Been-Huang

2014-01-01

Simple and fast photometric flow injection analysis system was developed for sensing of β-1,3-glucan from medicinal mushroom Ganoderma lucidum during fermentation. For this purpose, the chitosan-guar gum-silver nanoparticle-beta glucanase (Ch-GG-AgNPs-βG) beads and Ch-GG-AgNPs-GOD (glucose oxidase) beads were prepared. The bead packed mini-columns were then used to assemble a flow injection analysis (FIA) system for the detection of β-(1→3)-d-glucan biomarker or glucose. This colorimetric flow system can detect glucose and glucan with detection limits as low as 50ngmL(-1) and 100ngmL(-1) (S/N=3), respectively. The analysis time of this FIA was approximately 40s, which is faster than the previously reported glucan sensors. The glucose and glucan calibration curves were obtained in the range of 0.25-1.25μgmL(-1) (R(2)=0.988) and 0.2-1.0μgmL(-1)(R(2)=0.979), respectively. The applicability of the nano-bio-composite FIA sensor system for spiked and real β-(1→3)-d-glucan samples were tested, and the accuracy of the results were greater than 95%. Thus, the designed FIA provides a simple, interference free and rapid tool for monitoring glucose and β-glucan content, which can be used for various food samples with a little modification. Copyright © 2013 Elsevier B.V. All rights reserved.

Injectors for Multipoint Injection

NASA Technical Reports Server (NTRS)

Prociw, Lev Alexander (Inventor); Ryon, Jason (Inventor)

2015-01-01

An injector for a multipoint combustor system includes an inner air swirler which defines an interior flow passage and a plurality of swirler inlet ports in an upstream portion thereof. The inlet ports are configured and adapted to impart swirl on flow in the interior flow passage. An outer air cap is mounted outboard of the inner swirler. A fuel passage is defined between the inner air swirler and the outer air cap, and includes a discharge outlet between downstream portions of the inner air swirler and the outer air cap for issuing fuel for combustion. The outer air cap defines an outer air circuit configured for substantially unswirled injection of compressor discharge air outboard of the interior flow passage.

Focused Schlieren flow visualization studies of multiple venturi fuel injectors in a high pressure combustor

NASA Technical Reports Server (NTRS)

Chun, K. S.; Locke, R. J.; Lee, C. M.; Ratvasky, W. J.

1994-01-01

Multiple venturi fuel injectors were used to obtain uniform fuel distributions, better atomization and vaporization in the premixing/prevaporizing section of a lean premixed/prevaporized flame tube combustor. A focused Schlieren system was used to investigate the fuel/air mixing effectiveness of various fuel injection configurations. The Schlieren system was focused to a plane within the flow field of a test section equipped with optical windows. The focused image plane was parallel to the axial direction of the flow and normal to the optical axis. Images from that focused plane, formed by refracted light due to density gradients within the flow field, were filmed with a high-speed movie camera at framing rates of 8,000 frames per second (fps). Three fuel injection concepts were investigated by taking high-speed movies of the mixture flows at various operating conditions. The inlet air temperature was varied from 600 F to 1000 F, and inlet pressures from 80 psia to 150 psia. Jet-A fuel was used typically at an equivalence ratio of 0.5. The intensity variations of the digitized Schlieren images were analytically correlated to spatial density gradients of the mixture flows. Qualitative measurements for degree of mixedness, intensity of mixing, and mixing completion time are shown. Various mixing performance patterns are presented with different configurations of fuel injection points and operating conditions.

Effects of regional groundwater flow on the performance of an aquifer thermal energy storage system under continuous operation

NASA Astrophysics Data System (ADS)

Lee, Kun Sang

2014-01-01

Numerical investigations and a thermohydraulic evaluation are presented for two-well models of an aquifer thermal energy storage (ATES) system operating under a continuous flow regime. A three-dimensional numerical model for groundwater flow and heat transport is used to analyze the thermal energy storage in the aquifer. This study emphasizes the influence of regional groundwater flow on the heat transfer and storage of the system under various operation scenarios. For different parameters of the system, performances were compared in terms of the temperature of recovered water and the temperature field in the aquifer. The calculated temperature at the producing well varies within a certain range throughout the year, reflecting the seasonal (quarterly) temperature variation of the injected water. The pressure gradient across the system, which determines the direction and velocity of regional groundwater flow, has a substantial influence on the convective heat transport and performance of aquifer thermal storage. Injection/production rate and geometrical size of the aquifer used in the model also impact the predicted temperature distribution at each stage and the recovery water temperature. The hydrogeological-thermal simulation is shown to play an integral part in the prediction of performance of processes as complicated as those in ATES systems.

Delineating Fecal Contaminant Sources and Travel Times in a Karst Groundwater Basin, Inner Bluegrass Region, Kentucky

NASA Astrophysics Data System (ADS)

Ward, J. W.; Reed, T. M.; Fryar, A. E.; Brion, G. M.

2006-12-01

Because of preferential flowpaths via features such as sinkholes and conduits, karst aquifers are susceptible to non-point-source pollution from agricultural and urban drainage. With many karst aquifers being drinking- water sources, pathogens are contaminants of public health concern. Monitoring of microbial parameters (total coliforms [TC], atypical colonies [AC] and fecal coliform bacteria [FC]) transpired biweekly from December 2002 March 2004 and weekly from February October 2005 at Blue Hole Spring, which drains outlying farm lands and the town of Versailles in the Inner Bluegrass Region of Kentucky. Physicochemical parameters (discharge, temperature, specific conductance, and pH) were measured continuously during the entire period. The AC/TC ratio, which had been employed only in surface water-quality studies, was used with FC counts, precipitation and discharge data to determine sources of fecal loading to ground water as result of land-use practices. An AC/TC ratio < 10 demonstrates fresh input of fecal matter, while a larger ratio can represent a variety of occurrences, including aged fecal material input and/or lack of nutrient input into the system. AC/TC ratio data in the 2002 04 dataset behaved similarly to surface waters, with ratios > 10 during dry periods and < 10 during wet periods, while the 2005 data demonstrated a very irregular pattern. The difference in these two data sets indicated a compositional change within the groundwater basin between the two sampling periods, perhaps as a result of construction at a sewage treatment plant adjoining the spring. Solute (rhodamine WT fluorescent dye and bromide) and particle (1-μm diameter fluorescent latex microspheres) tracer tests were conducted during summer 2006 to examine contaminant mobility within the system under base-flow and storm-flow conditions. Rainfall was limited prior to the base-flow trace, totaling 0.025 cm within 2 weeks prior to the slug injection. Base-flow discharge averaged 400 m3/s and solute breakthrough began ~ 7.5 hours post injection and cleared the system after 77 hours. For the storm-flow trace, rainfall totaled 3.12 cm prior to injection, with another 9.35 cm of rainfall occurring over the two week monitoring period. Spring discharge during the storm-flow trace averaged 0.443 m3/s, with a maximum of 0.503 m3/s. Under storm-flow conditions solute breakthrough began ~ 2.33 hours post injection, with particle breakthrough beginning ~ 2.5 hours post injection. Bromide concentrations at the spring were < 0.1 ppm (the detection limit, or DL) 5.5 hours after injection, while rhodamine WT concentrations were < DL (0.1 ppb) 14 hours post injection. Microspheres were detected at the spring until 164 hours after injection. These traces demonstrate that storms in this karst basin can accelerate solute movement, and particles can remain mobile for as long as 1 week after introduction.

Coupling the Alkaline-Surfactant-Polymer Technology and The Gelation Technology to Maximize Oil Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malcolm Pitts; Jie Qi; Dan Wilson

2005-10-01

Gelation technologies have been developed to provide more efficient vertical sweep efficiencies for flooding naturally fractured oil reservoirs or more efficient areal sweep efficiency for those with high permeability contrast ''thief zones''. The field proven alkaline-surfactant-polymer technology economically recovers 15% to 25% OOIP more oil than waterflooding from swept pore space of an oil reservoir. However, alkaline-surfactant-polymer technology is not amenable to naturally fractured reservoirs or those with thief zones because much of injected solution bypasses target pore space containing oil. This work investigates whether combining these two technologies could broaden applicability of alkaline-surfactant-polymer flooding into these reservoirs. A priormore » fluid-fluid report discussed interaction of different gel chemical compositions and alkaline-surfactant-polymer solutions. Gel solutions under dynamic conditions of linear corefloods showed similar stability to alkaline-surfactant-polymer solutions as in the fluid-fluid analyses. Aluminum-polyacrylamide, flowing gels are not stable to alkaline-surfactant-polymer solutions of either pH 10.5 or 12.9. Chromium acetate-polyacrylamide flowing and rigid flowing gels are stable to subsequent alkaline-surfactant-polymer solution injection. Rigid flowing chromium acetate-polyacrylamide gels maintained permeability reduction better than flowing chromium acetate-polyacrylamide gels. Silicate-polyacrylamide gels are not stable with subsequent injection of either a pH 10.5 or a 12.9 alkaline-surfactant-polymer solution. Chromium acetate-xanthan gum rigid gels are not stable to subsequent alkaline-surfactant-polymer solution injection. Resorcinol-formaldehyde gels were stable to subsequent alkaline-surfactant-polymer solution injection. When evaluated in a dual core configuration, injected fluid flows into the core with the greatest effective permeability to the injected fluid. The same gel stability trends to subsequent alkaline-surfactant-polymer injected solution were observed. Aluminum citrate-polyacrylamide, resorcinol-formaldehyde, and the silicate-polyacrylamide gel systems did not produce significant incremental oil in linear corefloods. Both flowing and rigid flowing chromium acetate-polyacrylamide gels and the xanthan gum-chromium acetate gel system produced incremental oil with the rigid flowing gel producing the greatest amount. Higher oil recovery could have been due to higher differential pressures across cores. None of the gels tested appeared to alter alkaline-surfactant-polymer solution oil recovery. Total waterflood plus chemical flood oil recovery sequence recoveries were all similar. Chromium acetate-polyacrylamide gel used to seal fractured core maintain fracture closure if followed by an alkaline-surfactant-polymer solution. Chromium acetate gels that were stable to injection of alkaline-surfactant-polymer solutions at 72 F were stable to injection of alkaline-surfactant-polymer solutions at 125 F and 175 F in linear corefloods. Chromium acetate-polyacrylamide gels maintained diversion capability after injection of an alkaline-surfactant-polymer solution in stacked; radial coreflood with a common well bore. Xanthan gum-chromium acetate gels maintained gel integrity in linear corefloods after injection of an alkaline-surfactant-polymer solution at 125 F. At 175 F, Xanthan gum-chromium acetate gels were not stable either with or without subsequent alkaline-surfactant-polymer solution injection. Numerical simulation demonstrated that reducing the permeability of a high permeability zone of a reservoir with gel improved both waterflood and alkaline-surfactant-polymer flood oil recovery. A Minnelusa reservoir with both A and B sand production was simulated. A and B sands are separated by a shale layer. A sand and B sand waterflood oil recovery was improved by 196,000 bbls when a gel was placed in the B sand. A sand and B sand alkaline-surfactant-polymer flood oil recovery was improved by 596,000 bbls when a gel was placed in the B sand. Alkaline-surfactant-polymer flood oil recovery improvement over a waterflood was 392,000 bbls. Placing a gel into the B sand prior to an alkaline-surfactant-polymer flood resulted in 989,000 bbl more oil than only water injection.« less

Injection flow during steam condensation in silicon microchannels

NASA Astrophysics Data System (ADS)

Wu, Huiying; Yu, Mengmeng; Cheng, Ping; Wu, Xinyu

2007-08-01

An experimental investigation with the combined use of visualization and measurement techniques was performed on flow pattern transitions and wall temperature distributions in the condensation of steam in silicon microchannels. Three sets of trapezoidal silicon microchannels, having hydraulic diameters of 53.0 µm, 77.5 µm and 128.5 µm, respectively, were tested under different flow and cooling conditions. It was found that during the transitions from the annular flow to the slug/bubbly flow, a peculiar flow pattern injection flow appeared in silicon microchannels. The location at which the injection flow occurred was dependent on the Reynolds number, condensation number and hydraulic diameter. With increase in the Reynolds number, or decrease in the condensation number and hydraulic diameter, the injection flow moved towards the channel outlet. Based on the experimental results, a dimensionless correlation for the location of injection flow in functions of the Reynolds number, condensation number and hydraulic diameter was proposed for the first time. This correlation can be used to determine the annular flow zone and the slug/bubbly flow zone, and further to determine the dominating condensation flow pattern in silicon microchannels. Wall temperature distributions were also explored in this paper. It was found that near the injection flow, wall temperatures have a rapid decrease in the flow direction, while upstream and downstream far away from the injection flow, wall temperatures decreased mildly. Thus, the location of injection flow can also be determined based on the wall temperature distributions. The results presented in this paper help us to better understand the condensation flow and heat transfer in silicon microchannels.

Tuning transitions in rotating Rayleigh-Bénard convection

NASA Astrophysics Data System (ADS)

Joshi, Pranav; Kunnen, Rudie; Clercx, Herman

2015-11-01

Turbulent rotating Rayleigh-Bénard convection, depending on the system parameters, exhibits multiple flow states and transitions between them. The present experimental study aims to control the transitions between the flow regimes, and hence the system heat transfer characteristics, by introducing particles in the flow. We inject near-neutrally buoyant silver coated hollow ceramic spheres (~100 micron diameter) and measure the system response, i.e. the Nusselt number, at different particle concentrations and rotation rates. Both for rotating and non-rotating cases, most of the particles settle on the top and bottom plates in a few hours following injection. This rapid settling may be a result of ``trapping'' of particles in the laminar boundary layers at the horizontal walls. These particle layers on the heat-transfer surfaces reduce their effective conductivity, and consequently, lower the heat transfer rate. We calculate the effective system parameters by estimating, and accounting for, the temperature drop across the particle layers. Preliminary analysis suggests that the thermal resistance of the particle layers may affect the flow structure and delay the transition to the ``geostrophic'' regime. Financial support from Foundation for Fundamental Research on Matter.

Design and development of a direct injection system for cryogenic engines

NASA Astrophysics Data System (ADS)

Mutumba, Angela; Cheeseman, Kevin; Clarke, Henry; Wen, Dongsheng

2018-04-01

The cryogenic engine has received increasing attention due to its promising potential as a zero-emission engine. In this study, a new robust liquid nitrogen injection system was commissioned and set up to perform high-pressure injections into an open vessel. The system is used for quasi-steady flow tests used for the characterisation of the direct injection process for cryogenic engines. An electro-hydraulic valve actuator provides intricate control of the valve lift, with a minimum cycle time of 3 ms and a frequency of up to 20 Hz. With additional sub-cooling, liquid phase injections from 14 to 94 bar were achieved. Results showed an increase in the injected mass with the increase in pressure, and decrease in temperature. The injected mass was also observed to increases linearly with the valve lift. Better control of the injection process, minimises the number of variables, providing more comparable and repeatable sets of data. Implications of the results on the engine performance were also discussed.

Parametric effect on the mixing of the combination of a hydrogen porthole with an air porthole in transverse gaseous injection flow fields

NASA Astrophysics Data System (ADS)

Li, Lang-quan; Huang, Wei; Yan, Li; Li, Shi-bin

2017-10-01

The dual transverse injection system with a front hydrogen porthole and a rear air porthole arranged in tandem is proposed, and this is a realistic approach for mixing enhancement and penetration improvement of transverse injection in a scramjet combustor. The influence of this dual transverse injection system on mixing characteristics has been evaluated numerically based on grid independency analysis and code validation. The numerical approach employed in the current study has been validated against the available experimental data in the open literature, and the predicted wall static pressure distributions show reasonable agreement with the experimental data for the cases with different jet-to-crossflow pressure ratios. The obtained results predicted by the three-dimensional Reynolds-average Navier - Stokes (RANS) equations coupled with the two equation k-ω shear stress transport (SST) turbulence model show that the air pothole has an great impact on penetration depth and mixing efficiency, and the effect of air jet on flow field varies with different values of the aspect ratio. The air porthole with larger aspect ratio can increase the fuel penetration depth. However, when the aspect ratio is relatively small, the fuel penetration depth decreases, and even smaller than that of the single injection system. At the same time, the air pothole has a highly remarkable improvement on mixing efficiency, especially in the near field. The smaller the aspect ratio of the air porthole is, the higher the mixing efficiency in the near field is. This is due to its larger circulation in the near field. The dual injection system owns more losses of stagnation pressure than the single injection system.

Pulverized solid injection system. Application to laboratory burners and pyrometric temperature measurements

NASA Astrophysics Data System (ADS)

Therssen, E.; Delfosse, L.

1995-08-01

The design and setting up of a pulverized solid injection system for use in laboratory burners is presented. The original dual system consists of a screw feeder coupled to an acoustic sower. This laboratory device allows a good regularity and stability of the particle-gas mixture transported to the burner in a large scale of mass powder and gas vector rate flow. The thermal history of the particles has been followed by optical measurements. The quality of the particle cloud injected in the burner has been validated by the good agreement between experimental and modeling particle temperature.

Active Exhaust Silencing Systen For the Management of Auxillary Power Unit Sound Signatures

DTIC Science & Technology

2014-08-01

conceptual mass-less pistons are introduced into the system before and after the injection site, such that they will move exactly with the plane wave...Unit Sound Signatures, Helminen, et al. Page 2 of 7 either the primary source or the injected source. It is assumed that the pistons are ‘close...source, it causes both pistons to move identically. The pressures induced by the flow on the pistons do not affect the flow generated by the

A portable battery-powered flow injection monitor for the in situ analysis of nitrate in natural waters

PubMed Central

Blundell, N. J.; Hopkins, A.; Worsfold, P. J.; Casey, H.

1993-01-01

The design and performance of a portable, automated flow injection (FI)-based photometric monitor are described. The system is controlled by an in-house microcomputer system that enables the monitor (including a solid state detector) to operate from a 12 V battery supply. The monitor uses the cadmium reduction/diazotization method to analyse for nitrate with a linear range of 0 to 12 mg l-1 and a limit of detection of 0.05 mg l-1 (NO3-N). The hardware and software design, monitor performance and results obtained during unattended operation are presented. PMID:18924971

Anomalous transport in fracture networks: field scale experiments and modelling

NASA Astrophysics Data System (ADS)

Kang, P. K.; Le Borgne, T.; Bour, O.; Dentz, M.; Juanes, R.

2012-12-01

Anomalous transport is widely observed in different settings and scales of transport through porous and fractured geologic media. A common signature of anomalous transport is the late-time power law tailing in breakthrough curves (BTCs) during tracer tests. Various conceptual models of anomalous transport have been proposed, including multirate mass transfer, continuous time random walk, and stream tube models. Since different conceptual models can produce equally good fits to a single BTC, tracer test interpretation has been plagued with ambiguity. Here, we propose to resolve such ambiguity by analyzing BTCs obtained from both convergent and push-pull flow configurations at two different fracture planes. We conducted field tracer tests in a fractured granite formation close to Ploemeur, France. We observe that BTC tailing depends on the flow configuration and the injection fracture. Specifically the tailing disappears under push-pull geometry, and when we injected at a fracture with high flux (Figure 1). This indicates that for this fractured granite, BTC tailing is controlled by heterogeneous advection and not by matrix diffusion. To explain the change in tailing behavior for different flow configurations, we employ a simple lattice network model with heterogeneous conductivity distribution. The model assigns random conductivities to the fractures and solves the Darcy equation for an incompressible fluid, enforcing mass conservation at fracture intersections. The mass conservation constraint yields a correlated random flow through the fracture system. We investigate whether BTC tailing can be explained by the spatial distribution of preferential flow paths and stagnation zones, which is controlled by the conductivity variance and correlation length. By combining the results from the field tests and numerical modeling, we show that the reversibility of spreading is a key mechanism that needs to be captured. We also demonstrate the dominant role of the injection fracture on the tailing behavior: where we inject makes the difference in the tailing. Blue line is a BTC with injection into a slow velocity zone under convergent flow configuration. The late-time tailing observed for the convergent test diminished for push-pull experiment performed in the same zone(red line). Black line is a BTC with injection into a high velocity zone under convergent flow configuration. Insets: illustration of convergent and push-pull tracer tests using a double packer system.

A microchip-based flow injection-amperometry system with mercaptopropionic acid modified electroless gold microelectrode for the selective determination of dopamine.

PubMed

Wang, Yi; Luo, Jie; Chen, Hengwu; He, Qiaohong; Gan, Nin; Li, Tianhua

2008-09-12

A novel chip-based flow injection analysis (FIA) system has been developed for automatic, rapid and selective determination of dopamine (DA) in the presence of ascorbic acid (AA). The system is composed of a polycarbonate (PC) microfluidic chip with an electrochemical detector (ED), a gravity pump, and an automatic sample loading and injection unit. The selectivity of the ED was improved by modification of the gold working microelectrode, which was fabricated on the PC chip by UV-directed electroless gold plating, with a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA). Postplating treatment methods for cleaning the surface of electroless gold microelectrodes were investigated to ensure the formation of high quality SAMs. The effects of detection potential, flow rate, and sampling volume on the performance of the chip-based FIA system were studied. Under optimum conditions, a detection limit of 74 nmol L(-1) for DA was achieved at the sample throughput rate of 180 h(-1). A RSD of 0.9% for peak heights was observed for 19 runs of a 100 micromol L(-1) DA solution. Interference-free determination of DA could be conducted if the concentration ratio of AA-DA was no more than 10.

Methods and systems for fabricating high quality superconducting tapes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Majkic, Goran; Selvamanickam, Venkat

An MOCVD system fabricates high quality superconductor tapes with variable thicknesses. The MOCVD system can include a gas flow chamber between two parallel channels in a housing. A substrate tape is heated and then passed through the MOCVD housing such that the gas flow is perpendicular to the tape's surface. Precursors are injected into the gas flow for deposition on the substrate tape. In this way, superconductor tapes can be fabricated with variable thicknesses, uniform precursor deposition, and high critical current densities.

Study on the characters of control valve for ammonia injection in selective catalytic reduction (SCR) system of coal-fired power plant

NASA Astrophysics Data System (ADS)

Yao, Che; Li, Tao; Zhang, Hong; Zhou, Yanming

2017-08-01

In this paper, the characters of two control valves used for ammonia injection in SCR system are discussed. The linear/quadratic character between pressure drop/outlet flow rate and valve opening/dynamic pressure inlet are investigated using computational fluid dynamic (CFD) and response surface analysis (RSA) methods. The results show that the linear character of brake valve is significantly better than butterfly valve, which means that the brake valve is more suitable for ammonia injection adjustment than the butterfly valve.

Application of direct-injection detector integrated with the multi-pumping flow system to chemiluminescence determination of the total polyphenol index.

PubMed

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.

Thrust shock vector control of an axisymmetric conical supersonic nozzle via secondary transverse gas injection

NASA Astrophysics Data System (ADS)

Zmijanovic, V.; Lago, V.; Sellam, M.; Chpoun, A.

2014-01-01

Transverse secondary gas injection into the supersonic flow of an axisymmetric convergent-divergent nozzle is investigated to describe the effects of the fluidic thrust vectoring within the framework of a small satellite launcher. Cold-flow dry-air experiments are performed in a supersonic wind tunnel using two identical supersonic conical nozzles with the different transverse injection port positions. The complex three-dimensional flow field generated by the supersonic cross-flows in these test nozzles was examined. Valuable experimental data were confronted and compared with the results obtained from the numerical simulations. Different nozzle models are numerically simulated under experimental conditions and then further investigated to determine which parameters significantly affect thrust vectoring. Effects which characterize the nozzle and thrust vectoring performances are established. The results indicate that with moderate secondary to primary mass flow rate ratios, ranging around 5 %, it is possible to achieve pertinent vector side forces. It is also revealed that injector positioning and geometry have a strong effect on the shock vector control system and nozzle performances.

Experimental Investigation of Diffuser Hub Injection to Improve Centrifugal Compressor Stability

NASA Technical Reports Server (NTRS)

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.

Characterization and optimization of low cost microfluidic thread based electroanalytical device for micro flow injection analysis.

PubMed

Agustini, Deonir; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2017-01-25

The micro flow injection analysis (μFIA) is a powerful technique that uses the principles of traditional flow analysis in a microfluidic device and brings a number of improvements related to the consumption of reagents and samples, speed of analysis and portability. However, the complexity and cost of manufacturing processes, difficulty in integrating micropumps and the limited performance of systems employing passive pumps are challenges that must be overcome. Here, we present the characterization and optimization of a low cost device based on cotton threads as microfluidic channel to perform μFIA based on passive pumps with good analytical performance in a simple, easy and inexpensive way. The transport of solutions is made through cotton threads by capillary force facilitated by gravity. After studying and optimizing several features related to the device, were obtained a flow rate of 2.2 ± 0.1 μL s -1 , an analytical frequency of 208 injections per hour, a sample injection volume of 2.0 μL and a waste volume of approximately 40 μL per analysis. For chronoamperometric determination of naproxen, a detection limit of 0.29 μmol L -1 was reached, with a relative standard deviation (RSD) of 1.69% between injections and a RSD of 3.79% with five different devices. Thus, based on the performance presented by proposed microfluidic device, it is possible to overcome some limitations of the μFIA systems based on passive pumps and allow expansion in the use of this technique. Copyright © 2016 Elsevier B.V. All rights reserved.

Integration of continuous-flow sampling with microchip electrophoresis using poly(dimethylsiloxane)-based valves in a reversibly sealed device.

PubMed

Li, Michelle W; Martin, R Scott

2007-07-01

Here we describe a reversibly sealed microchip device that incorporates poly(dimethylsiloxane) (PDMS)-based valves for the rapid injection of analytes from a continuously flowing stream into a channel network for analysis with microchip electrophoresis. The microchip was reversibly sealed to a PDMS-coated glass substrate and microbore tubing was used for the introduction of gas and fluids to the microchip device. Two pneumatic valves were incorporated into the design and actuated on the order of hundreds of milliseconds, allowing analyte from a continuously flowing sampling stream to be injected into an electrophoresis separation channel. The device was characterized in terms of the valve actuation time and pushback voltage. It was also found that the addition of sodium dodecyl sulfate (SDS) to the buffer system greatly increased the reproducibility of the injection scheme and enabled the analysis of amino acids derivatized with naphthalene-2,3-dicarboxaldehyde/cyanide. Results from continuous injections of a 0.39 nL fluorescein plug into the optimized system showed that the injection process was reproducible (RSD of 0.7%, n = 10). Studies also showed that the device was capable of monitoring off-chip changes in concentration with a device lag time of 90 s. Finally, the ability of the device to rapidly monitor on-chip concentration changes was demonstrated by continually sampling from an analyte plug that was derivatized upstream from the electrophoresis/continuous flow interface. A reversibly sealed device of this type will be useful for the continuous monitoring and analysis of processes that occur either off-chip (such as microdialysis sampling) or on-chip from other integrated functions.

Injectable Solid Peptide Hydrogel as Cell Carrier: Effects of Shear Flow on Hydrogel and Cell Payload

PubMed Central

Yan, Congqi; Mackay, Michael E.; Czymmek, Kirk; Nagarkar, Radhika P.; Schneider, Joel P.; Pochan, Darrin J.

2012-01-01

β-hairpin peptide-based hydrogels are a class of injectable solid hydrogels that can deliver encapsulated cells or molecular therapies to a target site via syringe or catheter injection as a carrier material. These physical hydrogels can shear-thin and consequently flow as a low-viscosity material under a sufficient shear stress but immediately recover back into a solid upon removal of the stress, allowing them to be injected as preformed gel solids. Hydrogel behavior during flow was studied in a cylindrical capillary geometry that mimicked the actual situation of injection through a syringe needle in order to quantify effects of shear-thin injection delivery on hydrogel flow behavior and encapsulated cell payloads. It was observed that all β-hairpin peptide hydrogels investigated displayed a promising flow profile for injectable cell delivery: a central wide plug flow region where gel material and cell payloads experienced little or no shear rate and a narrow shear zone close to the capillary wall where gel and cells were subject to shear deformation. The width of the plug flow region was found to be weakly dependent on hydrogel rigidity and flow rate. Live-dead assays were performed on encapsulated MG63 cells three hours after injection flow and revealed that shear-thin delivery through the capillary had little impact on cell viability and the spatial distribution of encapsulated cell payloads. These observations help us to fundamentally understand how the gels flow during injection through a thin catheter and how they immediately restore mechanically and morphologically relative to pre-flow, static gels. PMID:22390812

Stabilising falling liquid film flows using feedback control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Alice B., E-mail: alice.thompson1@imperial.ac.uk; Gomes, Susana N.; Pavliotis, Grigorios A.

2016-01-15

Falling liquid films become unstable due to inertial effects when the fluid layer is sufficiently thick or the slope sufficiently steep. This free surface flow of a single fluid layer has industrial applications including coating and heat transfer, which benefit from smooth and wavy interfaces, respectively. Here, we discuss how the dynamics of the system are altered by feedback controls based on observations of the interface height, and supplied to the system via the perpendicular injection and suction of fluid through the wall. In this study, we model the system using both Benney and weighted-residual models that account for themore » fluid injection through the wall. We find that feedback using injection and suction is a remarkably effective control mechanism: the controls can be used to drive the system towards arbitrary steady states and travelling waves, and the qualitative effects are independent of the details of the flow modelling. Furthermore, we show that the system can still be successfully controlled when the feedback is applied via a set of localised actuators and only a small number of system observations are available, and that this is possible using both static (where the controls are based on only the most recent set of observations) and dynamic (where the controls are based on an approximation of the system which evolves over time) control schemes. This study thus provides a solid theoretical foundation for future experimental realisations of the active feedback control of falling liquid films.« less

Hydro-geomechanical behaviour of gas-hydrate bearing soils during gas production through depressurization and CO2 injection

NASA Astrophysics Data System (ADS)

Deusner, C.; Gupta, S.; Kossel, E.; Bigalke, N.; Haeckel, M.

2015-12-01

Results from recent field trials suggest that natural gas could be produced from marine gas hydrate reservoirs at compatible yields and rates. It appears, from a current perspective, that gas production would essentially be based on depressurization and, when facing suitable conditions, be assisted by local thermal stimulation or gas hydrate conversion after injection of CO2-rich fluids. Both field trials, onshore in the Alaska permafrost and in the Nankai Trough offshore Japan, were accompanied by different technical issues, the most striking problems resulting from un-predicted geomechanical behaviour, sediment destabilization and catastrophic sand production. So far, there is a lack of experimental data which could help to understand relevant mechanisms and triggers for potential soil failure in gas hydrate production, to guide model development for simulation of soil behaviour in large-scale production, and to identify processes which drive or, further, mitigate sand production. We use high-pressure flow-through systems in combination with different online and in situ monitoring tools (e.g. Raman microscopy, MRI) to simulate relevant gas hydrate production scenarios. Key components for soil mechanical studies are triaxial systems with ERT (Electric resistivity tomography) and high-resolution local strain analysis. Sand production control and management is studied in a novel hollow-cylinder-type triaxial setup with a miniaturized borehole which allows fluid and particle transport at different fluid injection and flow conditions. Further, the development of a large-scale high-pressure flow-through triaxial test system equipped with μ-CT is ongoing. We will present results from high-pressure flow-through experiments on gas production through depressurization and injection of CO2-rich fluids. Experimental data are used to develop and parametrize numerical models which can simulate coupled process dynamics during gas-hydrate formation and gas production.

Viscous Fingering in Deformable Systems

NASA Astrophysics Data System (ADS)

Guan, Jian Hui; MacMinn, Chris

2017-11-01

Viscous fingering is a classical hydrodynamic instability that occurs when an invading fluid is injected into a porous medium or a Hele-Shaw cell that contains a more viscous defending fluid. Recent work has shown that viscous fingering in a Hele-Shaw cell is supressed when the flow cell is deformable. However, the mechanism of suppression relies on a net volumetric expansion of the flow area. Here, we study flow in a novel Hele-Shaw cell consisting of a rigid bottom plate and a flexible top plate that deforms in a way that is volume-conserving. In other words, fluid injection into the flow cell leads to a local expansion of the flow area (outward displacement of the flexible surface) that must be coupled to non-local contraction (inward displacement of the flexible surface). We explore the impact of this volumetric confinement on steady viscous flow and on viscous fingering. We would like to thank EPSRC for the funding for this work.

Recent Electrochemical and Optical Sensors in Flow-Based Analysis

PubMed Central

Chailapakul, Orawon; Ngamukot, Passapol; Yoosamran, Alongkorn; Siangproh, Weena; Wangfuengkanagul, Nattakarn

2006-01-01

Some recent analytical sensors based on electrochemical and optical detection coupled with different flow techniques have been chosen in this overview. A brief description of fundamental concepts and applications of each flow technique, such as flow injection analysis (FIA), sequential injection analysis (SIA), all injection analysis (AIA), batch injection analysis (BIA), multicommutated FIA (MCFIA), multisyringe FIA (MSFIA), and multipumped FIA (MPFIA) were reviewed.

Piezoelectric detection of ion pairs between sulphonate and catecholamines for flow injection analysis of pharmaceutical preparations.

PubMed

Mo, Z; Long, X; Zhang, M

1999-03-01

Fundamentals of ion-pair flow injection with piezoelectric detection were investigated experimentally and theoretically for the adsorption of dodecyl phenylsulfonate and interfacial ion-pair formation with epinephrine and l-dopa on silver electrode of quartz crystal microbalance. The influences of sulfonate concentration and operating parameters on the frequency response were demonstrated and provided the possibility for the discriminating determination of mixtures. The selected system of ion-pair flow injection with piezoelectric detection was applied to the determination of epinephrine and l-dopa. Calibration curves were linear in ranges 4.00-850 and 3.50-730 mug ml(-1), with detection limits of 1.22 and 1.05 mug ml(-1) and sampling frequencies of 120 samples h(-1), for epinephrine and l-dopa, respectively. The method has been satisfactorily applied to the determination of catecholamines in pharmaceutical preparations.

Automated on-line renewable solid-phase extraction-liquid chromatography exploiting multisyringe flow injection-bead injection lab-on-valve analysis.

PubMed

Quintana, José Benito; Miró, Manuel; Estela, José Manuel; Cerdà, Víctor

2006-04-15

In this paper, the third generation of flow injection analysis, also named the lab-on-valve (LOV) approach, is proposed for the first time as a front end to high-performance liquid chromatography (HPLC) for on-line solid-phase extraction (SPE) sample processing by exploiting the bead injection (BI) concept. The proposed microanalytical system based on discontinuous programmable flow features automated packing (and withdrawal after single use) of a small amount of sorbent (<5 mg) into the microconduits of the flow network and quantitative elution of sorbed species into a narrow band (150 microL of 95% MeOH). The hyphenation of multisyringe flow injection analysis (MSFIA) with BI-LOV prior to HPLC analysis is utilized for on-line postextraction treatment to ensure chemical compatibility between the eluate medium and the initial HPLC gradient conditions. This circumvents the band-broadening effect commonly observed in conventional on-line SPE-based sample processors due to the low eluting strength of the mobile phase. The potential of the novel MSFI-BI-LOV hyphenation for on-line handling of complex environmental and biological samples prior to reversed-phase chromatographic separations was assessed for the expeditious determination of five acidic pharmaceutical residues (viz., ketoprofen, naproxen, bezafibrate, diclofenac, and ibuprofen) and one metabolite (viz., salicylic acid) in surface water, urban wastewater, and urine. To this end, the copolymeric divinylbenzene-co-n-vinylpyrrolidone beads (Oasis HLB) were utilized as renewable sorptive entities in the micromachined unit. The automated analytical method features relative recovery percentages of >88%, limits of detection within the range 0.02-0.67 ng mL(-1), and coefficients of variation <11% for the column renewable mode and gives rise to a drastic reduction in operation costs ( approximately 25-fold) as compared to on-line column switching systems.

Injection characteristics study of high-pressure direct injector for Compressed Natural Gas (CNG) using experimental and analytical method

NASA Astrophysics Data System (ADS)

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.

Three-dimensional numerical simulation for plastic injection-compression molding

NASA Astrophysics Data System (ADS)

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.

Down scaled Kjeldahl digestion and flow injection conductometric system for determination of protein content in some traditional northern Thai foods.

PubMed

Yanu, Pattama; Jakmunee, Jaroon

2017-09-01

A flow injection conductometric (FIC) system for determination of total Kjeldahl nitrogen (TKN) was developed for estimating total protein content in food. A small scale Kjeldahl digestion was performed with a short digestion time of only 20min. The digested solution was injected into the FIC system, and TKN was converted to ammonia gas in an alkaline donor stream of the system. The gas diffused through a membrane and dissolved into an acceptor stream causing an increase in conductivity as detected by a detector and recorded as a peak. Under the optimum condition, a linear calibration graph in the range of 4.00-100.00mgL -1 was obtained with LOD of 0.05mgL -1 . A good precision (0.04% RSD, n=11, 30.00mgNL -1 ) and high sample throughput of 72h -1 was achieved. The method was applied for determination of protein in some traditional northern Thai foods, revealing that they are good sources of proteins. Copyright © 2017 Elsevier Ltd. All rights reserved.

Distribution of effluent injected into the Boulder Zone of the Floridan aquifer system at the North District Wastewater Treatment Plant, southeastern Florida, 1997–2011

USGS Publications Warehouse

King, Jeffrey N.; Decker, Jeremy D.

2018-02-09

Nonhazardous, secondarily treated, domestic wastewater (effluent) has been injected about 1 kilometer below land surface into the Boulder Zone of the Floridan aquifer system at the North District Wastewater Treatment Plant in southeastern Florida. The Boulder Zone contains saline, nonpotable water. Effluent transport out of the injection zone is a risk of underground effluent injection. At the North District Wastewater Treatment Plant, injected effluent was detected outside the Boulder Zone. The U.S. Geological Survey, in cooperation with Miami-Dade Water and Sewer Department, investigated effluent transport from the Boulder Zone to overlying permeable zones in the Floridan aquifer system.One conceptual model is presented to explain the presence of effluent outside of the injection zone in which effluent injected into the Boulder Zone was transported to the Avon Park permeable zone, forced by buoyancy and injection pressure. In this conceptual model, effluent injected primarily into the Boulder Zone reaches a naturally occurring feature (a karst-collapse structure) near an injection well, through which the effluent is transported vertically upward to the uppermost major permeable zone of the Lower Floridan aquifer. The effluent is then transported laterally through the uppermost major permeable zone of the Lower Floridan aquifer to another naturally occurring feature northwest of the North District Wastewater Treatment Plant, through which it is then transported vertically upward into the Avon Park permeable zone. In addition, a leak within a monitoring well, between monitoring zones, allowed interflow between the Avon Park permeable zone and the Upper Floridan aquifer. A groundwater flow and effluent transport simulation of the hydrogeologic system at the North District Wastewater Treatment Plant, based on the hypothesized and non-unique conceptualization of the subsurface hydrogeology and flow system, generally replicated measured effluent constituent concentration trends. The model was calibrated to match observed concentration trends for total ammonium (NH4+) and total dissolved solids.The investigation qualitatively indicates that fractures, karst-collapse structures, faults, or other hydrogeologic features may permit effluent injected into the Boulder Zone to be transported to overlying permeable zones in the Floridan aquifer system. These findings, however, are qualitative because the locations of transport pathways that might exist from the Boulder Zone to the Avon Park permeable zone are largely unknown.

Spatial resolution of transport parameters in a subtropical karst conduit system during dry and wet seasons

NASA Astrophysics Data System (ADS)

Ender, Anna; Goeppert, Nadine; Goldscheider, Nico

2018-04-01

Karst aquifers are characterized by a high degree of hydrologic variability and spatial heterogeneity of transport parameters. Tracer tests allow the quantification of these parameters, but conventional point-to-point experiments fail to capture spatiotemporal variations of flow and transport. The goal of this study was to elucidate the spatial distribution of transport parameters in a karst conduit system at different flow conditions. Therefore, six tracer tests were conducted in an active and accessible cave system in Vietnam during dry and wet seasons. Injections and monitoring were done at five sites along the flow system: a swallow hole, two sites inside the cave, and two springs draining the system. Breakthrough curves (BTCs) were modeled with CXTFIT software using the one-dimensional advection-dispersion model and the two-region nonequilibrium model. In order to obtain transport parameters in the individual sections of the system, a multi-pulse injection approach was used, which was realized by using the BTCs from one section as input functions for the next section. Major findings include: (1) In the entire system, mean flow velocities increase from 183 to 1,043 m/h with increasing discharge, while (2) the proportion of immobile fluid regions decrease; (3) the lowest dispersivity was found at intermediate discharge; (4) in the individual cave sections, flow velocities decrease along the flow direction, related to decreasing gradients, while (5) dispersivity is highest in the middle section of the cave. The obtained results provide a valuable basis for the development of an adapted water management strategy for a projected water-supply system.

Flow-injection determination of trace hydrogen peroxide or glucose utilizing an amperometric biosensor based on glucose oxidase bound to a reticulated vitreous carbon electrode.

PubMed

Khayyami, M; Johansson, G; Kriz, D; Xie, B; Larsson, P O; Danielsson, B

1996-06-01

An electron transfer mediator, 8-dimethylamino-2,3-benzophenoxazine (Meldola Blue), dissolved in the carrier solution in a flow-injection system, was found to reduce the oxidation potential for hydrogen peroxide from 600-1200 mV without mediator to-100 mV vs. Ag/AgCl with the mediator present. The very low background current of reticulated vitreous carbon (RVC) at this potential makes it possible to detect very low levels of hydrogen peroxide or glucose. Glucose oxidase was covalently coupled with carbodiimide to RVC, and the RVC was formed into a column inserted in a flow-injection system. The calibration curve was linear from 30 nM to 10 microM glucose with 5 microM mediator. At higher mediator concentrations, the linear range was extended to 1000 microM, but with a much higher background current. The sample throughput was about 60 h(-1). The current response decreased to 50% of the original response after 20 days. The coulometric yield was high because the sample was pumped through the pores of the RVC. It was 16% and 55% at a flow rate of 1 ml min(-1) at mediator concentrations of 5 and 50 microM respectively.

Numerical Simulation of Atomization in Nozzle Injection Flow

NASA Astrophysics Data System (ADS)

Fan, Qinyin; Guo, Chenhai; Takagi, Tosimi; Narumiya, Kikuo; Hattori, Hiroshi

At the initial stage of injection, the injection flow has not yet broken up and in a range of small atmosphere pressure (16˜500KPa), the tip of the injection flow always forms a shape of mushroom. [1] [2] Moreover, the umbrella of the mushroom is always very big and its root is always very thin, especially when the atmosphere pressure is relatively low (88KPa, or 100mmHg). These phenomena are not known popularly and the reason of mushroom formation is not clear. In this paper, with the MARS method for simulating free surface, analysis of injection flow is practiced. The phenomena are reproduced and the reason is cleared that the formation of the mushroom is induced by the momentum exchange between the injection fuel flow with very high speed and the very complex flow of the air.

A rapid and accurate method for determining protein content in dairy products based on asynchronous-injection alternating merging zone flow-injection spectrophotometry.

PubMed

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.

MBM fuel feeding system design and evaluation for FBG pilot plant.

PubMed

Campbell, William A; Fonstad, Terry; Pugsley, Todd; Gerspacher, Regan

2012-06-01

A biomass fuel feeding system has been designed, constructed and evaluated for a fluidized bed gasifier (FBG) pilot plant at the University of Saskatchewan (Saskatoon, SK, Canada). The system was designed for meat and bone meal (MBM) to be injected into the gasifier at a mass flow-rate range of 1-5 g/s. The designed system consists of two stages of screw conveyors, including a metering stage which controlled the flow-rate of fuel, a rotary airlock and an injection conveyor stage, which delivered that fuel at a consistent rate to the FBG. The rotary airlock which was placed between these conveyors, proved unable to maintain a pressure seal, thus the entire conveying system was sealed and pressurized. A pneumatic injection nozzle was also fabricated, tested and fitted to the end of the injection conveyor for direct injection and dispersal into the fluidized bed. The 150 mm metering screw conveyor was shown to effectively control the mass output rate of the system, across a fuel output range of 1-25 g/s, while the addition of the 50mm injection screw conveyor reduced the irregularity (error) of the system output rate from 47% to 15%. Although material plugging was found to be an issue in the inlet hopper to the injection conveyor, the addition of air sparging ports and a system to pulse air into those ports was found to successfully eliminate this issue. The addition of the pneumatic injection nozzle reduced the output irregularity further to 13%, with an air supply of 50 slpm as the minimum air supply to drive this injector. After commissioning of this final system to the FBG reactor, the injection nozzle was found to plug with char however, and was subsequently removed from the system. Final operation of the reactor continues satisfactorily with the two screw conveyors operating at matching pressure with the fluidized bed, with the output rate of the system estimated based on system characteristic equations, and confirmed by static weight measurements made before and after testing. The error rate by this method is reported to be approximately 10%, which is slightly better than the estimated error rate of 15% for the conveyor system. The reliability of this measurement prediction method relies upon the relative consistency of the physical properties of MBM with respect to its bulk density and feeding characteristics. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effect of initial flow nonuniformity on second-stage fuel injection and combustion in a supersonic duct. [supersonic combustion ramjet engine

NASA Technical Reports Server (NTRS)

Russin, W. R.

1975-01-01

The effects of flow nonuniformity on second-stage hydrogen fuel injection and combustion in supersonic flow were evaluated. The first case, second-stage fuel injection into a uniform duct flow, produced data indicating that fuel mixing is considerably slower than estimates based on an empirical mixing correlation. The second-case, two-stage fuel injection (or second-stage fuel injection into a nonuniform duct flow), produced a large interaction between stages with extensive flow separation. For this case the measured wall pressure, heat transfer, and amount of reaction at the duct exit were significantly greater than estimates based on the mixing correlation. Substantially more second-stage fuel burned in the second case than in the first case. Overall effects of unmixedness/chemical kinetics were found not to be significant at the exit for stoichiometric fuel injection.

Biosensing of glucose in flow injection analysis system based on glucose oxidase-quantum dot modified pencil graphite electrode.

PubMed

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.

Combustor assembly in a gas turbine engine

DOEpatents

Wiebe, David J; Fox, Timothy A

2013-02-19

A combustor assembly in a gas turbine engine. The combustor assembly includes a combustor device coupled to a main engine casing, a first fuel injection system, a transition duct, and an intermediate duct. The combustor device includes a flow sleeve for receiving pressurized air and a liner disposed radially inwardly from the flow sleeve. The first fuel injection system provides fuel that is ignited with the pressurized air creating first working gases. The intermediate duct is disposed between the liner and the transition duct and defines a path for the first working gases to flow from the liner to the transition duct. An intermediate duct inlet portion is associated with a liner outlet and allows movement between the intermediate duct and the liner. An intermediate duct outlet portion is associated with a transition duct inlet section and allows movement between the intermediate duct and the transition duct.

Development of a Flow Injection System for Differential Pulse Amperometry and Its Application for Diazepam Determination

PubMed Central

Antunović, Vesna; Tešanović, Slavna; Perušković, Danica; Stevanović, Nikola; Baošić, Rada; Mandić, Snežana

2018-01-01

This work presents the development of a flow injection system for differential pulse amperometry (DPA) for diazepam determination in the presence of oxygen. The thin flow cell consisted of the bare glassy carbon electrode, reference silver/silver chloride, and stainless steel as the auxiliary electrode. Electrochemical reduction of diazepam (DZP) was characterised by cyclic voltammetry. Azomethine reduction peak was used for DZP quantification. The detector response was linear in the range 20–250 µmol/dm3 of diazepam, with a calculated detection limit of 3.83 µg/cm3. Intraday and interday precision were 1.53 and 10.8%, respectively. The method was applied on three beverage samples, energetic drink, and two different beer samples, and obtained recoveries were from 93.65 up to 104.96%. The throughoutput of the method was up to 90 analyses per hour. PMID:29744233

Enhancing the use of coals by gas reburning-sorbent injection: Volume 3 -- Gas reburning-sorbent injection at Edwards Unit 1, Central Illinois Light Company. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-03-01

Design work has been completed for a Gas Reburning-Sorbent Injection (GR-SI) system to reduce emissions of NO{sub x} and SO{sub 2} from a wall fired unit at Central Illinois Light Company`s Edwards Station Unit 1, located in Bartonville, Illinois. The goal of the project was to reduce emissions of NO{sub x} by 60%, from the as found baseline of 0.98 lb/MBtu and to reduce emissions of SO{sub 2} by 50%. Since the unit currently fires a blend of high sulfur Illinois coal and low sulfur Kentucky coal to meet an SO{sub 2} limit of 1.8 lb/MBtu, the goal at thismore » site was amended to meeting this limit while increasing the fraction of high sulfur coal to 57% from the current 15% level. GR-SI requires injection of natural gas into the furnace at the level of the top burner row, creating a fuel-rich zone in which NO{sub x} formed in the coal zone is reduced to N{sub 2}. Recycled flue gas is used to increase the reburning fuel jet momentum, resulting in enhanced mixing. Recycled flue gas is also used to cool the top row of burners which would not be in service during GR operation. Dry hydrated lime sorbent is injected into the upper furnace to react with SO{sub 2}, forming solid CaSO{sub 4} and CaSO{sub 3}, which are collected by the ESP. The system was designed to inject sorbent at a rate corresponding to a calcium (sorbent) to sulfur (coal) molar ratio of 2.0. The SI system design was optimized with respect to gas temperature, injection air flow rate, and sorbent dispersion. Sorbent injection air flow is equal to 3% of the combustion air. The design includes modifications of the ESP, sootblowing, and ash handling systems.« less

Renewable chemiluminescence optosensors based on implementation of bead injection principle with multicommutation.

PubMed

Domínguez-Romero, Juan C; Gilbert-López, Bienvenida; Beneito-Cambra, Miriam; Molina-Díaz, Antonio

2018-05-15

In this work, the implementation of Bead Injection with multicommutation-based flow systems is reported. A surface renewable chemiluminescence (CL) flow sensor is presented based on the use of CL reaction of luminol with H 2 O 2 . Dowex 1 × 8 beads with immobilized luminol onto them were injected in the flow system by means of a six-port rotary valve and were accommodated into a 1 mm optical glass flow cell placed just in front of the rectangular photosensor window with the same size than the cell wall. Automatic computer-controlled manipulation of both reagents and sample solutions was undertaken using a multicommutated flow system which comprises five three-way solenoid valves, a home-made electronic interface and a Java-written software. Once the chemiluminescence signal was registered, sensing beads were automatically discarded out with a six-port rotary valve without needing to reverse or stop the flow. As a proof of concept and example, the enhancement of the chemiluminescence signal produced by Co(II) on the luminol-H 2 O 2 reaction in alkaline medium was used for illustrating this implementation determining vitamin B 12 in pharmaceutical preparations (after mineralization for releasing Co(II)). The analytical performance of the approach was satisfactory, showing a linear dynamic range from 1.7 to 50 µg L -1 , a detection limit of 0.5 µg L -1 , RSD (%) of 5.3%, with a sampling frequency of 11 h -1 . The proposed approach was applied to different samples and the results were consistent with those obtained with a reference method based on ICP-MS. Based on the same reaction (or re-configuring the system to accommodate it to reaction requirements) the approach can also be applied to the determination of other metal ions such as Cr(III) and Fe(II) and appropriately extended to molecules of bioanalytical interest based e.g. in CL immunoassays, given its versatility. Copyright © 2018 Elsevier B.V. All rights reserved.

Hydrodynamic sample injection into short electrophoretic capillary in systems with a flow-gating interface.

PubMed

Opekar, František; Tůma, Petr

2017-01-13

An electrophoretic apparatus with a flow-gating interface has been developed, enabling hydrodynamic sequence injection of the sample into the separation capillary from the liquid flow by underpressure generated in the outlet electrophoretic vessel. The properties of the apparatus were tested on an artificial sample of an equimolar mixture of 100μM potassium and sodium ions and arginine. The repeatability of the injection of the tested ions expressed as RSD (in%) for the peak area, peak height and migration time was in the range 0.76-2.08, 0.18-0.68 and 0.28-0.48, respectively. Under optimum conditions, the apparatus was used for sequence monitoring of the reaction between the antidiabetic drug phenyl biguanide and the glycation agent methyl glyoxal. The reaction solution was continuously sampled by a microdialysis probe from a thermostated external vessel using a syringe pump at a flow rate of 3μLmin -1 and was injected into a separation capillary at certain time intervals. The electrophoretic separation progressed in a capillary with an internal diameter of 50μm with a length of 11.5cm and was monitored using a contactless conductivity detector. Copyright © 2016 Elsevier B.V. All rights reserved.

Thrust Augmented Nozzle for a Hybrid Rocket with a Helical Fuel Port

NASA Astrophysics Data System (ADS)

Marshall, Joel H.

A thrust augmented nozzle for hybrid rocket systems is investigated. The design lever-ages 3-D additive manufacturing to embed a helical fuel port into the thrust chamber of a hybrid rocket burning gaseous oxygen and ABS plastic as propellants. The helical port significantly increases how quickly the fuel burns, resulting in a fuel-rich exhaust exiting the nozzle. When a secondary gaseous oxygen flow is injected into the nozzle downstream of the throat, all of the remaining unburned fuel in the plume spontaneously ignites. This secondary reaction produces additional high pressure gases that are captured by the nozzle and significantly increases the motor's performance. Secondary injection and combustion allows a high expansion ratio (area of the nozzle exit divided by area of the throat) to be effective at low altitudes where there would normally be significantly flow separation and possibly an embedded shock wave due. The result is a 15 percent increase in produced thrust level with no loss in engine efficiency due to secondary injection. Core flow efficiency was increased significantly. Control tests performed using cylindrical fuel ports with secondary injection, and helical fuel ports without secondary injection did not exhibit this performance increase. Clearly, both the fuel-rich plume and secondary injection are essential features allowing the hybrid thrust augmentation to occur. Techniques for better design optimization are discussed.

Staged fuel and air injection in combustion systems of gas turbines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hughes, Michael John; Berry, Jonathan Dwight

A gas turbine including a working fluid flowpath extending aftward from a forward injector in a combustor. The combustor may include an inner radial wall, an outer radial wall, and, therebetween, a flow annulus, and a third radial wall formed about the outer radial wall that forms an outer flow annulus. A staged injector may intersect the flow annulus so to attain an injection point within the working fluid flowpath by which aftward and forward annulus sections are defined. Air directing structure may include an aftward intake section corresponding to the aftward annulus section and a forward intake section correspondingmore » to the forward annulus section. The air directing structure may include a switchback coolant flowpath to direct air from the compressor discharge cavity to the staged injector. The switchback coolant flowpath may include an upstream section through the flow annulus, and a downstream section through the outer flow annulus.« less

A Semi-Analytical Method for Rapid Estimation of Near-Well Saturation, Temperature, Pressure and Stress in Non-Isothermal CO2 Injection

NASA Astrophysics Data System (ADS)

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.

Investigation of Thrust Augmentation of a 1600-pound Thrust Centrifugal-flow-type Turbojet Engine by Injection of Refrigerants at Compressor Inlets

NASA Technical Reports Server (NTRS)

Jones, William L.; Dowman, Harry W.

1947-01-01

Investigations were conducted to determine effectiveness of refrigerants in increasing thrust of turbojet engines. Mixtures of water an alcohol were injected for a range of total flows up to 2.2 lb/sec. Kerosene was injected into inlets covering a range of injected flows up to approximately 30% of normal engine fuel flow. Injection of 2.0 lb/sec of water alone produced an increase in thrust of 35.8% of rate engine conditions and kerosene produced a negligible increase in thrust. Carbon dioxide increased thrust 23.5 percent.

Electrochemical biotin detection based on magnetic beads and a new magnetic flow cell for screen printed electrode.

PubMed

Biscay, Julien; González García, María Begoña; Costa García, Agustín

2015-01-01

The use of the first flow-cell for magnetic assays with an integrated magnet is reported here. The flow injection analysis system (FIA) is used for biotin determination. The reaction scheme is based on a one step competitive assay between free biotin and biotin labeled with horseradish peroxidase (B-HRP). The mixture of magnetic beads modified with streptavidin (Strep-MB), biotin and B-HRP is left 15 min under stirring and then a washing step is performed. After that, 100 μL of the mixture is injected and after 30s 100 μL of 3,3',5,5'-Tetramethylbenzidine (TMB) is injected and the FIAgram is recorded applying a potential of -0.2V. The linear range obtained is from 0.01 to 1 nM of biotin and the sensitivity is 758 nA/nM. The modification and cleaning of the electrode are performed in an easy way due to the internal magnet of the flow cell. Copyright © 2014 Elsevier B.V. All rights reserved.

Fast cholesterol detection using flow injection microfluidic device with functionalized carbon nanotubes based electrochemical sensor.

PubMed

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.

Centrifugal Compressor Surge Margin Improved With Diffuser Hub Surface Air Injection

NASA Technical Reports Server (NTRS)

Skoch, Gary J.

2002-01-01

Aerodynamic stability is an important parameter in the design of compressors for aircraft gas turbine engines. Compression system instabilities can cause compressor surge, which may lead to the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. The margin of safety is typically referred to as "surge margin." Achieving the highest possible level of surge margin while meeting design point performance objectives is the goal of the compressor designer. However, performance goals often must be compromised in order to achieve adequate levels of surge margin. Techniques to improve surge margin will permit more aggressive compressor designs. Centrifugal compressor surge margin improvement was demonstrated at the NASA Glenn Research Center by injecting air into the vaned diffuser of a 4:1-pressure-ratio centrifugal compressor. Tests were performed using injector nozzles located on the diffuser hub surface of a vane-island diffuser in the vaneless region between the impeller trailing edge and the diffuser-vane leading edge. The nozzle flow path and discharge shape were designed to produce an air stream that remained tangent to the hub surface as it traveled into the diffuser passage. Injector nozzles were located near the leading edge of 23 of the 24 diffuser vanes. One passage did not contain an injector so that instrumentation located in that passage would be preserved. Several orientations of the injected stream relative to the diffuser vane leading edge were tested over a range of injected flow rates. Only steady flow (nonpulsed) air injection was tested. At 100 percent of the design speed, a 15-percent improvement in the baseline surge margin was achieved with a nozzle orientation that produced a jet that was bisected by the diffuser vane leading edge. Other orientations also improved the baseline surge margin. Tests were conducted at speeds below the design speed, and similar results were obtained. In most cases, the greatest improvement in surge margin occurred at fairly low levels of injected flow rate. Externally supplied injection air was used in these experiments. However, the injected flow rates that provided the greatest benefit could be produced using injection air that is recirculating between the diffuser discharge and nozzles located in the diffuser vaneless region. Future experiments will evaluate the effectiveness of recirculating air injection.

A simple bubble-flowmeter with quasicontinuous registration.

PubMed

Ludt, H; Herrmann, H D

1976-07-22

The construction of a simple bubble-flow-meter is described. The instrument has the following features: 1. automatic bubble injection, 2. precise measurement of the bubble passage time by a digital counter, 3. quasicontinuous registration of the flow rate, 4. alternative run with clear fluid (water) and coloured fluid (blood), 5. low volume, 6. closed measuring system for measurements in low and high pressure systems.

A multisyringe flow injection Winkler-based spectrophotometric analyzer for in-line monitoring of dissolved oxygen in seawater.

PubMed

Horstkotte, Burkhard; Alonso, Juan Carlos; Miró, Manuel; Cerdà, Víctor

2010-01-15

An integrated analyzer based on the multisyringe flow injection analysis approach is proposed for the automated determination of dissolved oxygen in seawater. The entire Winkler method including precipitation of manganese(II) hydroxide, fixation of dissolved oxygen, dissolution of the oxidized manganese hydroxide precipitate, and generation of iodine and tri-iodide ion are in-line effected within the flow network. Spectrophotometric quantification of iodine and tri-iodide at the isosbestic wavelength of 466nm renders enhanced method reliability. The calibration function is linear up to 19mgL(-1) dissolved oxygen and an injection frequency of 17 per hour is achieved. The multisyringe system features a highly satisfying signal stability with repeatabilities of 2.2% RSD that make it suitable for continuous determination of dissolved oxygen in seawater. Compared to the manual starch-end-point titrimetric Winkler method and early reported automated systems, concentrations and consumption of reagents and sample are reduced up to hundredfold. The versatility of the multisyringe assembly was exploited in the implementation of an ancillary automatic batch-wise Winkler titrator using a single syringe of the module for accurate titration of the released iodine/tri-iodide with thiosulfate.

Simulation of the Transverse Injection of a Pulsed Jet from the Surface of a Flat Plate into a Supersonic Flow

NASA Astrophysics Data System (ADS)

Volkov, K. N.; Emelyanov, V. N.; Yakovchuk, M. S.

2017-11-01

The transverse injection of a pulsed jet into a supersonic flow for thrust vectoring in solid rocket motors is investigated. The gas flow through the injection nozzle is controlled by a piston which performs reciprocating motion. Reynolds-averaged Navier-Stokes equations and the ( k- ɛ) turbulence model equations are discretized using the finite volume method and moving grids. The pressure distributions on the plate surface obtained using various approaches to the description of the flow field and difference schemes are compared. The solution obtained for the case of injection of a pulsed jet is compared with the solution for the case where a valve prevents gas flow through the injection nozzle. The dependence of the control force produced by gas injection on time is investigated.

Solution mining systems and methods for treating hydrocarbon containing formations

DOEpatents

Vinegar, Harold J [Bellaire, TX; de Rouffignac, Eric Pierre [Rijswijk, NL; Schoeling, Lanny Gene [Katy, TX

2009-07-14

A method for treating an oil shale formation comprising nahcolite is disclosed. The method includes providing a first fluid to a portion of the formation through at least two injection wells. A second fluid is produced from the portion through at least one injection well until at least two injection wells are interconnected such that fluid can flow between the two injection wells. The second fluid includes at least some nahcolite dissolved in the first fluid. The first fluid is injected through one of the interconnected injection wells. The second fluid is produced from at least one of the interconnected injection wells. Heat is provided from one or more heaters to the formation to heat the formation. Hydrocarbon fluids are produced from the formation.

The dependence of permeability on effective stress from flow tests at hot dry rock reservoirs at Rosemanowes (Cornwall) and Fenton Hill (New Mexico)

USGS Publications Warehouse

Nathenson, M.

1999-01-01

Effective stress is the primary control on permeability and thus on flow and water loss for two-well hot dry rock systems involving injection and production that have been tested to date. Theoretical relations are derived for the flow between an injector and producer, including the dependence of permeability on effective stress. Four relations for permeability as a function of effective stress are used to match field data for the hot dry rock systems at Rosemanowes, Cornwall, and Fenton Hill, New Mexico. The flow and water loss behavior of these systems are well explained by the influence of effective stress on permeability. All four relations for permeability as a function of effective stress are successful in matching the field data, but some have difficulty in determining unique values for elastic and hydrologic parameters.Effective stress is the primary control on permeability and thus on flow and water loss for two-well hot dry rock systems involving injection and production that have been tested to date. Theoretical relations are derived for the flow between an injector and producer, including the dependence of permeability on effective stress. Four relations for permeability as a function of effective stress are used to match field data for the hot dry rock systems at Rosemanowes, Cornwall, and Fenton Hill, New Mexico. The flow and water loss behavior of these systems are well explained by the influence of effective stress on permeability. All four relations for permeability as a function of effective stress are successful in matching the field data, but some have difficulty in determining unique values for elastic and hydrologic parameters.

The Use of Flow-Injection Analysis with Chemiluminescence Detection of Aqueous Ferrous Iron in Waters Containing High Concentrations of Organic Compounds

PubMed Central

Borman, Christopher J.; Sullivan, B. Patrick; Eggleston, Carrick M.; Colberg, Patricia J. S.

2009-01-01

An evaluation of flow-injection analysis with chemiluminescence detection (FIA-CL) to quantify Fe2+(aq) in freshwaters was performed. Iron-coordinating and/or iron-reducing compounds, dissolved organic matter (DOM), and samples from two natural water systems were used to amend standard solutions of Fe2+(aq). Slopes of the response curves from ferrous iron standards (1 – 100 nM) were compared to the response curves of iron standards containing the amendments. Results suggest that FIA-CL is not suitable for systems containing ascorbate, hydroxylamine, cysteine or DOM. Little or no change in sensitivity occurred in solutions of oxalate and glycine or in natural waters with little organic matter. PMID:22408532

Cell-specific transmembrane injection of molecular cargo with gold nanoparticle-generated transient plasmonic nanobubbles

PubMed Central

Lukianova-Hleb, Ekaterina Y.; Wagner, Daniel S.; Brenner, Malcolm K.; Lapotko, Dmitri O.

2012-01-01

Optimal cell therapies require efficient, selective and rapid delivery of molecular cargo into target cells without compromising their viability. Achieving these goals ex vivo in bulk heterogeneous multi-cell systems such as human grafts is impeded by low selectivity and speed of cargo delivery and by significant damage to target and non-target cells. We have developed a cell level approach for selective and guided trans-membrane injection of extracellular cargo into specific target cells using transient plasmonic nanobubbles (PNB) as cell-specific nano-injectors. As a technical platform for this method we developed a laser flow cell processing system. The PNB injection method and flow system were tested in heterogeneous cell suspensions of target and non-target cells for delivery of Dextran-FITC dye into squamous cell carcinoma HN31 cells and transfection of human T-cells with a green fluorescent protein-encoding plasmid. In both models the method demonstrated single cell type selectivity, high efficacy of delivery (96% both for HN31 cells T-cells), speed of delivery (nanoseconds) and viability of treated target cells (96% for HN31 cells and 75% for T-cells). The PNB injection method may therefore be beneficial for real time processing of human grafts without removal of physiologically important cells. PMID:22521612

Cell-specific transmembrane injection of molecular cargo with gold nanoparticle-generated transient plasmonic nanobubbles.

PubMed

Lukianova-Hleb, Ekaterina Y; Wagner, Daniel S; Brenner, Malcolm K; Lapotko, Dmitri O

2012-07-01

Optimal cell therapies require efficient, selective and rapid delivery of molecular cargo into target cells without compromising their viability. Achieving these goals ex vivo in bulk heterogeneous multi-cell systems such as human grafts is impeded by low selectivity and speed of cargo delivery and by significant damage to target and non-target cells. We have developed a cell level approach for selective and guided transmembrane injection of extracellular cargo into specific target cells using transient plasmonic nanobubbles (PNB) as cell-specific nano-injectors. As a technical platform for this method we developed a laser flow cell processing system. The PNB injection method and flow system were tested in heterogeneous cell suspensions of target and non-target cells for delivery of Dextran-FITC dye into squamous cell carcinoma HN31 cells and transfection of human T-cells with a green fluorescent protein-encoding plasmid. In both models the method demonstrated single cell type selectivity, high efficacy of delivery (96% both for HN31 cells T-cells), speed of delivery (nanoseconds) and viability of treated target cells (96% for HN31 cells and 75% for T-cells). The PNB injection method may therefore be beneficial for real time processing of human grafts without removal of physiologically important cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Visualisation of diesel injector with neutron imaging

NASA Astrophysics Data System (ADS)

Lehmann, E.; Grünzweig, C.; Jollet, S.; Kaiser, M.; Hansen, H.; Dinkelacker, F.

2015-12-01

The injection process of diesel engines influences the pollutant emissions. The spray formation is significantly influenced by the internal flow of the injector. One of the key parameters here is the generation of cavitation caused by the geometry and the needle lift. In modern diesel engines the injection pressure is established up to 3000 bar. The details of the flow and phase change processes inside the injector are of increasing importance for such injectors. With these experimental measurements the validation of multiphase and cavitation models is possible for the high pressure range. Here, for instance, cavitation effects can occur. Cavitation effects in the injection port area destabilize the emergent fuel jet and improve the jet break-up. The design of the injection system in direct-injection diesel engines is an important challenge, as the jet breakup, the atomization and the mixture formation in the combustion chamber are closely linked. These factors have a direct impact on emissions, fuel consumption and performance of an engine. The shape of the spray at the outlet is determined by the internal flow of the nozzle. Here, geometrical parameters, the injection pressure, the injection duration and the cavitation phenomena play a major role. In this work, the flow dependency in the nozzles are analysed with the Neutron-Imaging. The great advantage of this method is the penetrability of the steel structure while a high contrast to the fuel is given due to the interaction of the neutrons with the hydrogen amount. Compared to other methods (optical with glass structures) we can apply real components under highest pressure conditions. During the steady state phase of the injection various cavitation phenomena are visible in the injector, being influenced by the nozzle geometry and the fuel pressure. Different characteristics of cavitation in the sac and spray hole can be detected, and the spray formation in the primary breakup zone is influenced.

Experiment data report for Semiscale Mod-1 Test S-05-1 (alternate ECC injection test)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feldman, E. M.; Patton, Jr., M. L.; Sackett, K. E.

Recorded test data are presented for Test S-05-1 of the Semiscale Mod-1 alternate ECC injection test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-05-1 was conducted from initial conditions of 2263 psia and 544/sup 0/F to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the cold leg broken loop piping. During the test, cooling water was injected into the vessel lower plenum to simulatemore » emergency core coolant injection in a PWR, with the flow rate based on system volume scaling.« less

Static Flow Characteristics of a Mass Flow Injecting Valve

NASA Technical Reports Server (NTRS)

Mattern, Duane; Paxson, Dan

1995-01-01

A sleeve valve is under development for ground-based forced response testing of air compression systems. This valve will be used to inject air and to impart momentum to the flow inside the first stage of a multi-stage compressor. The valve was designed to deliver a maximum mass flow of 0.22 lbm/s (0.1 kg/s) with a maximum valve throat area of 0.12 sq. in (80 sq. mm), a 100 psid (689 KPA) pressure difference across the valve and a 68 F, (20 C) air supply. It was assumed that the valve mass flow rate would be proportional to the valve orifice area. A static flow calibration revealed a nonlinear valve orifice area to mass flow relationship which limits the maximum flow rate that the valve can deliver. This nonlinearity was found to be caused by multiple choking points in the flow path. A simple model was used to explain this nonlinearity and the model was compared to the static flow calibration data. Only steady flow data is presented here. In this report, the static flow characteristics of a proportionally controlled sleeve valve are modelled and validated against experimental data.

Reactive multiphase flow at the pore-scale: the melting of a crystalline framework during the injection of buoyant hot volatiles

NASA Astrophysics Data System (ADS)

Andrea, P.; Huber, C.; Bachmann, O.; Chopard, B.

2010-12-01

Multiphase reactive flows occur naturally in various environments in the shallow subsurface, e.g. CO2 injections in saturated reservoirs, exsolved methane flux in shallow sediments and H20-CO2 volatiles in magmatic systems. Because of their multiphase nature together with the nonlinear feedbacks between reactions (dissolution/melting or precipitation) and the flow field at the pore-scale, the study of these dynamical processes remains a great challenge. In this study we focus on the injection of buoyant hot volatiles exsolved from a magmatic intrusion underplating a crystal-rich magma (porous medium). We use some simple theoretical models and a pore-scale multiphase reactive lattice Boltzmann model to investigate how the heat carried by the volatile phase affects the evolution of the porous medium spatially and temporally. We find that when the reaction rate is relatively slow and when the injection rate of volatiles is large (high injection Capillary number), the dissolution of the porous medium can be described by a local Peclet number (ratio of advective to diffusive flux of heat/reactant in the main gas channel). When the injection rate of volatile is reduced, or when the reaction rate is large, the dynamics transition to more complex regimes, where subvertical gas channels are no longer stable and can break into disconnected gas slugs. For the case of the injection of hot volatiles in crystal-rich magmatic systems, we find that the excess enthalpy advected by buoyant volatiles penetrates the porous medium over distances ~r Pe, where r is the average radius of the volatile channel (~pore size). The transport of heat by buoyant gases through a crystal mush is therefore in most cases limited to distances < meters. Our results also suggest that buoyant volatiles can carry chemical species (Li,F, Cl) far into a mush as their corresponding local Peclet number is several orders of magnitude greater than that for heat, owing to their low diffusion coefficients.

Experimental study on the performance of the vapor injection refrigeration system with an economizer for intermediate pressures

NASA Astrophysics Data System (ADS)

Moon, Chang-Uk; Choi, Kwang-Hwan; Yoon, Jung-In; Kim, Young-Bok; Son, Chang-Hyo; Ha, Soo-Jung; Jeon, Min-Ju; An, Sang-Young; Lee, Joon-Hyuk

2018-04-01

In this study, to investigate the performance characteristics of vapor injection refrigeration system with an economizer at an intermediate pressure, the vapor injection refrigeration system was analyzed under various experiment conditions. As a result, the optimum design data of the vapor injection refrigeration system with an economizer were obtained. The findings from this study can be summarized as follows. The mass flow rate through the compressor increases with intermediate pressure. The compression power input showed an increasing trend under all the test conditions. The evaporation capacity increased and then decreased at the intermediate pressure, and as such, it became maximum at the given intermediate pressure. The increased mass flow rate of the by-passed refrigerant enhanced the evaporation capacity at the low medium pressure range, but the increased saturation temperature limited the subcooling degree of the liquid refrigerant after the application of the economizer when the intermediate pressure kept rising, and degenerated the evaporation capacity. The coefficient of performance (COP) increased and then decreased with respect to the intermediate pressures under all the experiment conditions. Nevertheless, there was an optimum intermediate pressure for the maximum COP under each experiment condition. Therefore, the optimum intermediate pressure in this study was found at -99.08 kPa, which is the theoretical standard medium pressure under all the test conditions.

Enhancing resolution of free-flow zone electrophoresis via a simple sheath-flow sample injection.

PubMed

Yang, Ying; Kong, Fan-Zhi; Liu, Ji; Li, Jun-Min; Liu, Xiao-Ping; Li, Guo-Qing; Wang, Ju-Fang; Xiao, Hua; Fan, Liu-Yin; Cao, Cheng-Xi; Li, Shan

2016-07-01

In this work, a simple and novel sheath-flow sample injection method (SFSIM) is introduced to reduce the band broadening of free-flow zone electrophoresis separation in newly developed self-balance free-flow electrophoresis instrument. A needle injector was placed in the center of the separation inlet, into which the BGE and sample solution were pumped simultaneously. BGE formed sheath flow outside the sample stream, resulting in less band broadening related to hydrodynamics and electrodynamics. Hemoglobin and C-phycocyanin were successfully separated by the proposed method in contrast to the poor separation of free-flow electrophoresis with the traditional injection method without sheath flow. About 3.75 times resolution enhancement could be achieved by sheath-flow sample injection method. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mathematical Model of Two Phase Flow in Natural Draft Wet-Cooling Tower Including Flue Gas Injection

NASA Astrophysics Data System (ADS)

Hyhlík, Tomáš

2016-03-01

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.

Mixing and reactions in multiphase flow through porous media

NASA Astrophysics Data System (ADS)

Jimenez-Martinez, J.; Le Borgne, T.; Meheust, Y.; Porter, M. L.; De Anna, P.; Hyman, J.; Tabuteau, H.; Turuban, R.; Carey, J. W.; Viswanathan, H. S.

2016-12-01

The understanding and quantification of flow and transport processes in multiphase systems remains a grand scientific and engineering challenge in natural and industrial systems (e.g., soils and vadose zone, CO2 sequestration, unconventional oil and gas extraction, enhanced oil recovery). Beyond the kinetic of the chemical reactions, mixing processes in porous media play a key role in controlling both fluid-fluid and fluid-solid reactions. However, conventional continuum-scale models and theories oversimplify and/or ignore many important pore-scale processes. Multiphase flows, with the creation of highly heterogeneous fluid velocity fields (i.e., low velocities regions or stagnation zones, and high velocity regions or preferential paths), makes conservative and reactive transport more complex. We present recent multi-scale experimental developments and theoretical approaches to quantify transport, mixing, and reaction and their coupling with multiphase flows. We discuss our main findings: i) the sustained concentration gradients and enhanced reactivity in a two-phase system for a continuous injection, and the comparison with a pulse line injection; ii) the enhanced mixing by a third mobile-immiscible phase; and iii) the role that capillary forces play in the localization of the fluid-solid reactions. These experimental results are for highly-idealized geometries, however, the proposed models are related to basic porous media and unsaturated flow properties, and could be tested on more complex systems.

Rapid determination of tartaric acid in wines.

PubMed

Bastos, Sandra S T; Tafulo, Paula A R; Queirós, Raquel B; Matos, Cristina D; Sales, M Goreti F

2009-08-01

A flow-spectrophotometric method is proposed for the routine determination of tartaric acid in wines. The reaction between tartaric acid and vanadate in acetic media is carried out in flowing conditions and the subsequent colored complex is monitored at 475 nm. The stability of the complex and the corresponding formation constant are presented. The effect of wavelength and pH was evaluated by batch experiments. The selected conditions were transposed to a flow-injection analytical system. Optimization of several flow parameters such as reactor lengths, flow-rate and injection volume was carried out. Using optimized conditions, a linear behavior was observed up to 1000 microg mL(-1) tartaric acid, with a molar extinction coefficient of 450 L mg(-1) cm(-1) and +/- 1 % repeatability. Sample throughput was 25 samples per hour. The flow-spectrophotometric method was satisfactorily applied to the quantification of TA in wines from different sources. Its accuracy was confirmed by statistical comparison to the conventional Rebelein procedure and to a certified analytical method carried out in a routine laboratory.

Simultaneous injection-effective mixing analysis of palladium.

PubMed

Teshima, Norio; Noguchi, Daisuke; Joichi, Yasutaka; Lenghor, Narong; Ohno, Noriko; Sakai, Tadao; Motomizu, Shoji

2010-01-01

A novel concept of simultaneous injection-effective mixing analysis (SIEMA) is proposed, and a SIEMA method applied to the spectrophotometric determination of palladium using a water-soluble chromogenic reagent has been demonstrated. The flow configuration of SIEMA is a hybrid format of flow injection analysis (FIA), sequential injection analysis (SIA) and multicommutation in flow-based analysis. Sample and reagent solutions are aspirated into each holding coil through each solenoid valve by a syringe pump, and then the zones are simultaneously dispensed (injected) into a mixing coil by reversed flow toward a detector through a confluence point. This results in effective mixing and rapid detection with low reagent consumption.

The impact of injector-based contrast agent administration in time-resolved MRA.

PubMed

Budjan, Johannes; Attenberger, Ulrike I; Schoenberg, Stefan O; Pietsch, Hubertus; Jost, Gregor

2018-05-01

Time-resolved contrast-enhanced MR angiography (4D-MRA), which allows the simultaneous visualization of the vasculature and blood-flow dynamics, is widely used in clinical routine. In this study, the impact of two different contrast agent injection methods on 4D-MRA was examined in a controlled, standardized setting in an animal model. Six anesthetized Goettingen minipigs underwent two identical 4D-MRA examinations at 1.5 T in a single session. The contrast agent (0.1 mmol/kg body weight gadobutrol, followed by 20 ml saline) was injected using either manual injection or an automated injection system. A quantitative comparison of vascular signal enhancement and quantitative renal perfusion analyses were performed. Analysis of signal enhancement revealed higher peak enhancements and shorter time to peak intervals for the automated injection. Significantly different bolus shapes were found: automated injection resulted in a compact first-pass bolus shape clearly separated from the recirculation while manual injection resulted in a disrupted first-pass bolus with two peaks. In the quantitative perfusion analyses, statistically significant differences in plasma flow values were found between the injection methods. The results of both qualitative and quantitative 4D-MRA depend on the contrast agent injection method, with automated injection providing more defined bolus shapes and more standardized examination protocols. • Automated and manual contrast agent injection result in different bolus shapes in 4D-MRA. • Manual injection results in an undefined and interrupted bolus with two peaks. • Automated injection provides more defined bolus shapes. • Automated injection can lead to more standardized examination protocols.

Tracer airflow measurement system (TRAMS)

DOEpatents

Wang, Duo [Albany, CA

2007-04-24

A method and apparatus for measuring fluid flow in a duct is disclosed. The invention uses a novel high velocity tracer injector system, an optional insertable folding mixing fan for homogenizing the tracer within the duct bulk fluid flow, and a perforated hose sampling system. A preferred embodiment uses CO.sub.2 as a tracer gas for measuring air flow in commercial and/or residential ducts. In extant commercial buildings, ducts not readily accessible by hanging ceilings may be drilled with readily plugged small diameter holes to allow for injection, optional mixing where desired using a novel insertable foldable mixing fan, and sampling hose.

Characterization of 3-Dimensional PET Systems for Accurate Quantification of Myocardial Blood Flow.

PubMed

Renaud, Jennifer M; Yip, Kathy; Guimond, Jean; Trottier, Mikaël; Pibarot, Philippe; Turcotte, Eric; Maguire, Conor; Lalonde, Lucille; Gulenchyn, Karen; Farncombe, Troy; Wisenberg, Gerald; Moody, Jonathan; Lee, Benjamin; Port, Steven C; Turkington, Timothy G; Beanlands, Rob S; deKemp, Robert A

2017-01-01

Three-dimensional (3D) mode imaging is the current standard for PET/CT systems. Dynamic imaging for quantification of myocardial blood flow with short-lived tracers, such as 82 Rb-chloride, requires accuracy to be maintained over a wide range of isotope activities and scanner counting rates. We proposed new performance standard measurements to characterize the dynamic range of PET systems for accurate quantitative imaging. 82 Rb or 13 N-ammonia (1,100-3,000 MBq) was injected into the heart wall insert of an anthropomorphic torso phantom. A decaying isotope scan was obtained over 5 half-lives on 9 different 3D PET/CT systems and 1 3D/2-dimensional PET-only system. Dynamic images (28 × 15 s) were reconstructed using iterative algorithms with all corrections enabled. Dynamic range was defined as the maximum activity in the myocardial wall with less than 10% bias, from which corresponding dead-time, counting rates, and/or injected activity limits were established for each scanner. Scatter correction residual bias was estimated as the maximum cavity blood-to-myocardium activity ratio. Image quality was assessed via the coefficient of variation measuring nonuniformity of the left ventricular myocardium activity distribution. Maximum recommended injected activity/body weight, peak dead-time correction factor, counting rates, and residual scatter bias for accurate cardiac myocardial blood flow imaging were 3-14 MBq/kg, 1.5-4.0, 22-64 Mcps singles and 4-14 Mcps prompt coincidence counting rates, and 2%-10% on the investigated scanners. Nonuniformity of the myocardial activity distribution varied from 3% to 16%. Accurate dynamic imaging is possible on the 10 3D PET systems if the maximum injected MBq/kg values are respected to limit peak dead-time losses during the bolus first-pass transit. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Pneumatic testing in 45-degree-inclined boreholes in ash-flow tuff near Superior, Arizona

USGS Publications Warehouse

LeCain, G.D.

1995-01-01

Matrix permeability values determined by single-hole pneumatic testing in nonfractured ash-flow tuff ranged from 5.1 to 20.3 * 1046 m2 (meters squared), depending on the gas-injection rate and analysis method used. Results from the single-hole tests showed several significant correlations between permeability and injection rate and between permeability and test order. Fracture permeability values determined by cross-hole pneumatic testing in fractured ash-flow tuff ranged from 0.81 to 3.49 * 1044 m2, depending on injection rate and analysis method used. Results from the cross-hole tests monitor intervals showed no significant correlation between permeability and injection rate; however, results from the injection interval showed a significant correlation between injection rate and permeability. Porosity estimates from the 'cross-hole testing range from 0.8 to 2.0 percent. The maximum temperature change associated with the pneumatic testing was 1.2'(2 measured in the injection interval during cross-hole testing. The maximum temperature change in the guard and monitor intervals was O.Ip C. The maximum error introduced into the permeability values due to temperature fluctuations is approximately 4 percent. Data from temperature monitoring in the borehole indicated a positive correlation between the temperature decrease in the injection interval during recovery testing and the gas-injection rate. The thermocouple psychrometers indicated that water vapor was condensing in the boreholes during testing. The psychrometers in the guard and monitor intervals detected the drier injected gas as an increase in the dry bulb reading. The relative humidity in the test intervals was always higher than the upper measurement limit of the psychrometers. Although the installation of the packer system may have altered the water balance of the borehole, the gas-injection testing resulted in minimal or no changes in the borehole relative humidity.

Injection dynamics of gelled propellants

NASA Astrophysics Data System (ADS)

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, unsteady and asymmetric flow structures are revealed as a series of vortices generated from the unstable vena contracta. Here, flows are characterized by an orifice design, manifold/core injection velocity ratio, Reynolds number and rheology. A significant decrease of discharge coefficients is noted with increasing the manifold flow. As the manifold crossflow increases, stronger friction losses are exerted on the leeward, and lead to larger hydraulic losses across the injector. In addition, calculations show that discharge coefficients decrease and the unsteadiness is mitigated as the viscosity increases by fluid rheology variations. A larger and more distinct horseshoe vortex is observed, and pulsation magnitude and viscosity fluctuations are mitigated with increasing viscosity. The oscillation frequency, however, remains unchanged even though the viscosity curves at the high shear rate are modified. All these observations confirm the conclusion that the role of viscous damping and flow resistance is more critical in cross-fed injection conditions than in axially-fed one.

Multi-Phase Modeling of Rainbird Water Injection

NASA Technical Reports Server (NTRS)

Vu, Bruce T.; Moss, Nicholas; Sampson, Zoe

2014-01-01

This paper describes the use of a Volume of Fluid (VOF) multiphase model to simulate the water injected from a rainbird nozzle used in the sound suppression system during launch. The simulations help determine the projectile motion for different water flow rates employed at the pad, as it is critical to know if water will splash on the first-stage rocket engine during liftoff.

Automation of flow injection gas diffusion-ion chromatography for the nanomolar determination of methylamines and ammonia in seawater and atmospheric samples

PubMed Central

Gibb, Stuart W.; Wood, John W.; Fauzi, R.; Mantoura, C.

1995-01-01

The automation and improved design and performance of Flow Injection Gas Diffusion-Ion Chromatography (FIGD-IC), a novel technique for the simultaneous analysis of trace ammonia (NH3) and methylamines (MAs) in aqueous media, is presented. Automated Flow Injection Gas Diffusion (FIGD) promotes the selective transmembrane diffusion of MAs and NH3 from aqueous sample under strongly alkaline (pH > 12, NaOH), chelated (EDTA) conditions into a recycled acidic acceptor stream. The acceptor is then injected onto an ion chromatograph where NH3 and the MAs are fully resolved as their cations and detected conductimetrically. A versatile PC interfaced control unit and data capture unit (DCU) are employed in series to direct the selonoid valve switching sequence, IC operation and collection of data. Automation, together with other modifications improved both linearily (R2 > 0.99 MAs 0-100 nM, NH3 0-1000 nM) and precision (<8%) of FIGD-IC at nanomolar concentrations, compared with the manual procedure. The system was successfully applied to the determination of MAs and NH3 in seawater and in trapped particulate and gaseous atmospheric samples during an oceanographic research cruise. PMID:18925047

Flow injection analysis-flame atomic absorption spectrometry system for indirect determination of sulfite after on-line reduction of solid-phase manganese (IV) dioxide reactor.

PubMed

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.

Viral Tracer Studies Indicate Contamination of Marine Waters by Sewage Disposal Practices in Key Largo, Florida

PubMed Central

Paul, J. H.; Rose, J. B.; Brown, J.; Shinn, E. A.; Miller, S.; Farrah, S. R.

1995-01-01

Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys. PMID:16535046

Vertical-deformation, water-level, microgravity, geodetic, water-chemistry, and flow-rate data collected during injection, storage, and recovery tests at Lancaster, Antelope Valley, California, September 1995 through September 1998

USGS Publications Warehouse

Metzger, Loren F.; Ikehara, Marti E.; Howle, James F.

2001-01-01

A series of freshwater injection, storage, and recovery tests were conducted from September 1995 through September 1998 to evaluate the feasibility of artificially recharging ground water in the Lancaster area of the Antelope Valley, California. The tests used two production wells at a well field located in the southern part of the city of Lancaster. Monitoring networks were established at or in the vicinity of the test site to measure vertical deformation of the aquifer system, water-level fluctuations, land-surface deformation, water chemistry, and injection well flow rates during water injection and recovery. Data presented in this report were collected from a dual extensometer; 10 piezometers; 1 barometer; 27 active or abandoned production wells; 31 gravity stations; 124 bench marks; 1 permanent and 1 temporary continuous Global Positioning System (GPS) station; 3 tiltmeters; and 2 electromagnetic flowmeters from September 1995 through September 1998. This report discusses the location and design of the monitoring networks and the methods used to collect and process the data, and presents the data in tables and graphs.

Viral tracer studies indicate contamination of marine waters by sewage disposal practices in key largo, Florida.

PubMed

Paul, J H; Rose, J B; Brown, J; Shinn, E A; Miller, S; Farrah, S R

1995-06-01

Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys.

Assessment of key transport parameters in a karst system under different dynamic conditions based on tracer experiments: the Jeita karst system, Lebanon

NASA Astrophysics Data System (ADS)

Doummar, Joanna; Margane, Armin; Geyer, Tobias; Sauter, Martin

2018-03-01

Artificial tracer experiments were conducted in the mature karst system of Jeita (Lebanon) under various flow conditions using surface and subsurface tracer injection points, to determine the variation of transport parameters (attenuation of peak concentration, velocity, transit times, dispersivity, and proportion of immobile and mobile regions) along fast and slow flow pathways. Tracer breakthrough curves (TBCs) observed at the karst spring were interpreted using a two-region nonequilibrium approach (2RNEM) to account for the skewness in the TBCs' long tailings. The conduit test results revealed a discharge threshold in the system dynamics, beyond which the transport parameters vary significantly. The polynomial relationship between transport velocity and discharge can be related to the variation of the conduit's cross-sectional area. Longitudinal dispersivity in the conduit system is not a constant value (α = 7-10 m) and decreases linearly with increasing flow rate because of dilution effects. Additionally, the proportion of immobile regions (arising from conduit irregularities) increases with decreasing water level in the conduit system. From tracer tests with injection at the surface, longitudinal dispersivity values are found to be large (8-27 m). The tailing observed in some TBCs is generated in the unsaturated zone before the tracer actually arrives at the major subsurface conduit draining the system. This work allows the estimation and prediction of the key transport parameters in karst aquifers. It shows that these parameters vary with time and flow dynamics, and they reflect the geometry of the flow pathway and the origin of infiltrating (potentially contaminated) recharge.

Transport modeling and multivariate adaptive regression splines for evaluating performance of ASR systems in freshwater aquifers

NASA Astrophysics Data System (ADS)

Forghani, Ali; Peralta, Richard C.

2017-10-01

The study presents a procedure using solute transport and statistical models to evaluate the performance of aquifer storage and recovery (ASR) systems designed to earn additional water rights in freshwater aquifers. The recovery effectiveness (REN) index quantifies the performance of these ASR systems. REN is the proportion of the injected water that the same ASR well can recapture during subsequent extraction periods. To estimate REN for individual ASR wells, the presented procedure uses finely discretized groundwater flow and contaminant transport modeling. Then, the procedure uses multivariate adaptive regression splines (MARS) analysis to identify the significant variables affecting REN, and to identify the most recovery-effective wells. Achieving REN values close to 100% is the desire of the studied 14-well ASR system operator. This recovery is feasible for most of the ASR wells by extracting three times the injectate volume during the same year as injection. Most of the wells would achieve RENs below 75% if extracting merely the same volume as they injected. In other words, recovering almost all the same water molecules that are injected requires having a pre-existing water right to extract groundwater annually. MARS shows that REN most significantly correlates with groundwater flow velocity, or hydraulic conductivity and hydraulic gradient. MARS results also demonstrate that maximizing REN requires utilizing the wells located in areas with background Darcian groundwater velocities less than 0.03 m/d. The study also highlights the superiority of MARS over regular multiple linear regressions to identify the wells that can provide the maximum REN. This is the first reported application of MARS for evaluating performance of an ASR system in fresh water aquifers.

Multisyringe flow injection analysis hyphenated with liquid core waveguides for the development of cleaner spectroscopic analytical methods: improved determination of chloride in waters.

PubMed

Maya, Fernando; Estela, José Manuel; Cerdà, Víctor

2009-07-01

In this work, the hyphenation of the multisyringe flow injection analysis technique with a 100-cm-long pathlength liquid core waveguide has been accomplished. The Cl-/Hg(SCN)2/Fe3+ reaction system for the spectrophotometric determination of chloride (Cl(-)) in waters was used as chemical model. As a result, this classic analytical methodology has been improved, minimizing dramatically the consumption of reagents, in particular, that of the highly biotoxic chemical Hg(SCN)2. The proposed method features a linear dynamic range composed of two steps between (1) 0.2-2 and (2) 2-8 mg Cl- L(-1), thus extended applicability due to on-line sample dilution (up to 400 mg Cl- L(-1)). It also presents improved limits of detection and quantification of 0.06 and 0.20 mg Cl- L(-1), respectively. The coefficient of variation and the injection throughput were 1.3% (n = 10, 2 mg Cl- L(-1)) and 21 h(-1). Furthermore, a very low consumption of reagents per Cl- determination of 0.2 microg Hg(II) and 28 microg Fe3+ has been achieved. The method was successfully applied to the determination of Cl- in different types of water samples. Finally, the proposed system is critically compared from a green analytical chemistry point of view against other flow systems for the same purpose.

An experimental study of wall-injected flows in a rectangular cylinder

NASA Astrophysics Data System (ADS)

Perrotta, A.; Romano, G. P.; Favini, B.

2018-01-01

An experimental investigation of the flow inside a rectangular cylinder with air injected continuously along the wall is performed. This kind of flow is a two-dimensional approximation of what happens inside a solid rocket motor, where the lateral grain burns expelling exhaust gas or in processes with air filtration or devices to attain uniform flows. We propose a brief derivation of some analytical solutions and a comparison between these solutions and experimental data, which are obtained using the particle image velocimetry technique, to provide a global reconstruction of the flowfield. The flow, which enters orthogonal to the injecting wall, turns suddenly its direction being pushed towards the exit of the chamber. Under the incompressible and inviscid flow hypothesis, two analytical solutions are reported and compared. The first one, known as Hart-McClure solution, is irrotational and the injection velocity is non-perpendicular to the injecting wall. The other one, due to Taylor and Culick, has non-zero vorticity and constant, vertical injection velocity. The comparison with laminar solutions is useful to assess whether transition to turbulence is reached and how the disturbance thrown in by the porous injection influences and modifies those solutions.

Coupled Hydro-Mechanical Modeling of Fluid Geological Storage

NASA Astrophysics Data System (ADS)

Castelletto, N.; Garipov, T.; Tchelepi, H. A.

2013-12-01

The accurate modeling of the complex coupled physical processes occurring during the injection and the post-injection period is a key factor for assessing the safety and the feasibility of anthropogenic carbon dioxide (CO2) sequestration in subsurface formations. In recent years, it has become widely accepted the importance of the coupling between fluid flow and geomechanical response in constraining the sustainable pressure buildup caused by fluid injection relative to the caprock sealing capacity, induced seismicity effects and ground surface stability [e.g., Rutqvist, 2012; Castelletto et al., 2013]. Here, we present a modeling approach based on a suitable combination of Finite Volumes (FVs) and Finite Elements (FEs) to solve the coupled system of partial differential equations governing the multiphase flow in a deformable porous medium. Specifically, a FV method is used for the flow problem while the FE method is adopted to address the poro-elasto-plasticity equations. The aim of the present work is to compare the performance and the robustness of unconditionally stable sequential-implicit schemes [Kim et al., 2011] and the fully-implicit method in solving the algebraic systems arising from the discretization of the governing equations, for both normally conditioned and severely ill-conditioned problems. The two approaches are tested against well-known analytical solutions and experimented with in a realistic application of CO2 injection in a synthetic aquifer. References: - Castelletto N., G. Gambolati, and P. Teatini (2013), Geological CO2 sequestration in multi-compartment reservoirs: Geomechanical challenges, J. Geophys. Res. Solid Earth, 118, 2417-2428, doi:10.1002/jgrb.50180. - Kim J., H. A. Tchelepi, and R. Juanes (2011), Stability, accuracy and efficiency of sequential methods for coupled flow and geomechanics, SPE J., 16(2), 249-262. - Rutqvist J. (2012), The geomechanics of CO2 storage in deep sedimentary formations, Geotech. Geol. Eng., 30, 525-551.

Systems and methods for multi-fluid geothermal energy systems

DOEpatents

Buscheck, Thomas A.

2017-09-19

A method for extracting geothermal energy from a geothermal reservoir formation. A production well is used to extract brine from the reservoir formation. At least one of nitrogen (N.sub.2) and carbon dioxide (CO.sub.2) may be used to form a supplemental working fluid which may be injected into a supplemental working fluid injection well. The supplemental working fluid may be used to augment a pressure of the reservoir formation, to thus drive a flow of the brine out from the reservoir formation.

Dispersion-convolution model for simulating peaks in a flow injection system.

PubMed

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.

Numerical modeling of multidimensional flow in seals and bearings used in rotating machinery

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Tam, L. T.; Przekwas, A.; Muszynska, A.; Braun, M. J.; Mullen, R. L.

1988-01-01

The rotordynamic behavior of turbomachinery is critically dependent on fluid dynamic rotor forces developed by various types of seals and bearings. The occurrence of self-excited vibrations often depends on the rotor speed and load. Misalignment and rotor wobbling motion associated with differential clearance were often attributed to stability problems. In general, the rotative character of the flowfield is a complex three dimensional system with secondary flow patterns that significantly alter the average fluid circumferential velocity. A multidimensional, nonorthogonal, body-fitted-grid fluid flow model is presented that describes the fluid dynamic forces and the secondary flow pattern development in seals and bearings. Several numerical experiments were carried out to demonstrate the characteristics of this complex flowfield. Analyses were performed by solving a conservation form of the three dimensional Navier-Stokes equations transformed to those for a rotating observer and using the general-purpose computer code PHOENICS with the assumptions that the rotor orbit is circular and that static eccentricity is zero. These assumptions have enabled a precise steady-state analysis to be used. Fluid injection from ports near the seal or bearing center increased fluid-film direct dynamic stiffness and, in some cases, significantly increased quadrature dynamic stiffness. Injection angle and velocity could be used for active rotordynamic control; for example, injection, when compared with no injection, increased direct dynamic stiffness, which is an important factor for hydrostatic bearings.

Using dye tracing to establish groundwater flow paths in a limestone marble aquifer, University of California, Santa Cruz, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, J.; Bertschinger, V.; Aley, T.

1993-04-01

Areas underlain by karst aquifers are characterized by soluble rock with sinkholes, caves, and a complex underground drainage network. Groundwater issues such as flow direction, well pumping impacts, spring recharge areas, and potential contamination transport routes are greatly complicated by the unique structure of karst aquifers. Standard aquifer analysis techniques cannot be applied unless the structure of the karst aquifer is understood. Water soluble fluorescent dyes are a powerful tool for mapping the irregular subsurface connections and flow paths in karst aquifers. Mapping the subsurface connections allows reasonable estimates of the hydrologic behavior of the aquifer. Two different fluorescent dyesmore » were injected at two points in a limestone karst aquifer system beneath the University of California, Santa Cruz campus. Flow paths in the marble were thought to be closely tied to easily recognized geomorphic alignments of sinkholes associated with fault and fracture zones. The dye tests revealed unexpected and highly complex interconnections. These complex flow paths only partially corresponded to previous surface mapping and aerial photo analysis of fracture systems. Several interfingering but hydrologically unconnected flow paths evidently exist within the cavernous aquifer. For example, dye did not appear at some discharge springs close to the dye injection points, but did appear at more distant springs. This study shows how a dye tracing study in a small, well-defined limestone body can shed light on a variety of environmental and hydrological issues, including potential well pumping impact areas, wellhead protection and recharge areas, parking lot runoff injection to aquifers, and drainage routes from hazardous materials storage areas.« less

CFD Modeling of Swirl and Nonswirl Gas Injections into Liquid Baths Using Top Submerged Lances

NASA Astrophysics Data System (ADS)

Huda, Nazmul; Naser, J.; Brooks, G.; Reuter, M. A.; Matusewicz, R. W.

2010-02-01

Fluid flow phenomena in a cylindrical bath stirred by a top submerged lance (TSL) gas injection was investigated by using the computational fluid dynamic (CFD) modeling technique for an isothermal air-water system. The multiphase flow simulation, based on the Euler-Euler approach, elucidated the effect of swirl and nonswirl flow inside the bath. The effects of the lance submergence level and the air flow rate also were investigated. The simulation results for the velocity fields and the generation of turbulence in the bath were validated against existing experimental data from the previous water model experimental study by Morsi et al.[1] The model was extended to measure the degree of the splash generation for different liquid densities at certain heights above the free surface. The simulation results showed that the two-thirds lance submergence level provided better mixing and high liquid velocities for the generation of turbulence inside the water bath. However, it is also responsible for generating more splashes in the bath compared with the one-third lance submergence level. An approach generally used by heating, ventilation, and air conditioning (HVAC) system simulations was applied to predict the convective mixing phenomena. The simulation results for the air-water system showed that mean convective mixing for swirl flow is more than twice than that of nonswirl in close proximity to the lance. A semiempirical equation was proposed from the results of the present simulation to measure the vertical penetration distance of the air jet injected through the annulus of the lance in the cylindrical vessel of the model, which can be expressed as L_{va} = 0.275( {do - di } )Frm^{0.4745} . More work still needs to be done to predict the detail process kinetics in a real furnace by considering nonisothermal high-temperature systems with chemical reactions.

A LabVIEW®-based software for the control of the AUTORAD platform: a fully automated multisequential flow injection analysis Lab-on-Valve (MSFIA-LOV) system for radiochemical analysis.

PubMed

Barbesi, Donato; Vicente Vilas, Víctor; Millet, Sylvain; Sandow, Miguel; Colle, Jean-Yves; Aldave de Las Heras, Laura

2017-01-01

A LabVIEW ® -based software for the control of the fully automated multi-sequential flow injection analysis Lab-on-Valve (MSFIA-LOV) platform AutoRAD performing radiochemical analysis is described. The analytical platform interfaces an Arduino ® -based device triggering multiple detectors providing a flexible and fit for purpose choice of detection systems. The different analytical devices are interfaced to the PC running LabVIEW ® VI software using USB and RS232 interfaces, both for sending commands and receiving confirmation or error responses. The AUTORAD platform has been successfully applied for the chemical separation and determination of Sr, an important fission product pertinent to nuclear waste.

Determination of local values of gas and liquid mass flux in highly loaded two-phase flow

NASA Technical Reports Server (NTRS)

Burick, R. J.; Scheuerman, C. H.; Falk, A. Y.

1974-01-01

A measurement system using a deceleration probe was designed for determining the local values of gas and liquid mass flux in various gas/liquid droplet sprayfields. The system was used to characterize two-phase flowfields generated by gas/liquid rocket-motor injectors. Measurements were made at static pressures up to 500 psia and injected mass flow ratios up to 20. The measurement system can also be used at higher pressures and in gas/solid flowfields.

A simple and sensitive flow injection method based on the catalytic activity of CdS quantum dots in an acidic permanganate chemiluminescence system for determination of formaldehyde in water and wastewater.

PubMed

Khataee, Alireza; Lotfi, Roya; Hasanzadeh, Aliyeh; Iranifam, Mortaza

2016-04-01

A simple and sensitive flow injection chemiluminescence (CL) method in which CdS quantum dots (QDs) enhanced the CL intensity of a KMnO4-formaldehyde (HCHO) reaction was offered for the determination of HCHO. This CL system was based on the catalytic activity of CdS QDs and their participation in the CL resonance energy transfer (CRET) phenomenon. A possible mechanism for the supplied CL system was proposed using the kinetic curves of the CL systems and the spectra of CL, photoluminescence (PL) and ultraviolet-visible (UV-Vis). The emanated CL intensity of the KMnO4-CdS QDs system was amplified in the presence of a trace level of HCHO. Based on this enhancement effect, a simple and sensitive flow injection CL method was suggested for the determination of HCHO concentration in environmental water and wastewater samples. Under selected optimized experimental conditions, the increased CL intensity was proportional to the HCHO concentration in the range of 0.03-4.5 μg L(-1) and 4.5-10.0 μg L(-1). The detection limits (3σ) were 0.0003 μg L(-1) and 1.2 μg L(-1). The relative standard deviations (RSD%) for eleven replicate determinations of 4.0 μg L(-1) HCHO were 2.2%. Furthermore, the feasibility of the developed method was investigated via the determination of HCHO concentration in environmental water and wastewater samples.

Simulation of Liquid Injection Thrust Vector Control for Mars Ascent Vehicle

NASA Technical Reports Server (NTRS)

Gudenkauf, Jared

2017-01-01

The Jet Propulsion Laboratory is currently in the initial design phase for a potential Mars Ascent Vehicle; which will be landed on Mars, stay on the surface for period of time, collect samples from the Mars 2020 rover, and then lift these samples into orbit around Mars. The engineers at JPL have down selected to a hybrid wax-based fuel rocket using a liquid oxidizer based on nitrogen tetroxide, or a Mixed Oxide of Nitrogen. To lower the gross lift-off mass of the vehicle the thrust vector control system will use liquid injection of the oxidizer to deflect the thrust of the main nozzle instead of using a gimbaled nozzle. The disadvantage of going with the liquid injection system is the low technology readiness level with a hybrid rocket. Presented in this paper is an effort to simulate the Mars Ascent Vehicle hybrid rocket nozzle and liquid injection thrust vector control system using the computational fluid dynamic flow solver Loci/Chem. This effort also includes determining the sensitivity of the thrust vector control system to a number of different design variables for the injection ports; including axial location, number of adjacent ports, injection angle, and distance between the ports.

Studies on the injection molding of polyvinyl chloride: Analysis of viscous heating and degradation in simple geometries

NASA Astrophysics Data System (ADS)

Garcia, Jose Luis

2000-10-01

In injection molding processes, computer aided engineering (CAE) allows processors to evaluate different process parameters in order to achieve complete filling of a cavity and, in some cases, it predicts shrinkage and warpage. However, because commercial computational packages are used to design complex geometries, detail in the thickness direction is limited. Approximations in the thickness direction lead to the solution of a 2½-D problem instead of a 3-D problem. These simplifications drastically reduce computational times and memory requirements. However, these approximations hinder the ability to predict thermal and/or mechanical degradation. The goal of this study was to determine the degree of degradation during PVC injection molding and to compare the results with a computational model. Instead of analyzing degradation in complex geometries, the computational analysis and injection molding trials were performed on typical sections found in complex geometries, such as flow in a tube, flow in a rectangular channel, and radial flow. This simplification reduces the flow problem to a 1-D problem and allows one to develop a computational model with a higher level of detail in the thickness direction, essential for the determination of degradation. Two different geometries were examined in this study: a spiral mold, in order to approximate the rectangular channel, and a center gated plate for the radial flow. Injection speed, melt temperature, and shot size were varied. Parts varying in degree of degradation, from no to severe degradation, were produced to determine possible transition points. Furthermore, two different PVC materials were used, low and high viscosity, M3800 and M4200, respectively (The Geon Company, Avon Lake, OH), to correlate the degree of degradation with the viscous heating observed during injection. It was found that a good agreement between experimental and computational results was obtained only if the reaction was assumed to be more thermally sensitive than found in literature. The results from this study show that, during injection, the activation energy for degradation was 65 kcal/mol, compared to 17--30 kcal/mol found in literature for quiescent systems.

Surface self-potential patterns related to transmissive fracture trends during a water injection test

NASA Astrophysics Data System (ADS)

DesRoches, A. J.; Butler, K. E.; MacQuarrie, K. TB

2018-03-01

Variations in self-potential (SP) signals were recorded over an electrode array during a constant head injection test in a fractured bedrock aquifer. Water was injected into a 2.2 m interval isolated between two inflatable packers at 44 m depth in a vertical well. Negative SP responses were recorded on surface corresponding to the start of the injection period with strongest magnitudes recorded in electrodes nearest the well. SP response decreased in magnitude at electrodes further from the well. Deflation of the packer system resulted in a strong reversal in the SP signal. Anomalous SP patterns observed at surface at steady state were found to be aligned with dominant fracture strike orientations found within the test interval. Numerical modelling of fluid and current flow within a simplified fracture network showed that azimuthal patterns in SP are mainly controlled by transmissive fracture orientations. The strongest SP gradients occur parallel to hydraulic gradients associated with water flowing out of the transmissive fractures into the tighter matrix and other less permeable cross-cutting fractures. Sensitivity studies indicate that increasing fracture frequency near the well increases the SP magnitude and enhances the SP anomaly parallel to the transmissive set. Decreasing the length of the transmissive fractures leads to more fluid flow into the matrix and into cross-cutting fractures proximal to the well, resulting in a more circular and higher magnitude SP anomaly. Results from the field experiment and modelling provide evidence that surface-based SP monitoring during constant head injection tests has the ability to identify groundwater flow pathways within a fractured bedrock aquifer.

Phase Field Model of Hydraulic Fracturing in Poroelastic Media: Fracture Propagation, Arrest, and Branching Under Fluid Injection and Extraction

NASA Astrophysics Data System (ADS)

Santillán, David; Juanes, Ruben; Cueto-Felgueroso, Luis

2018-03-01

The simulation of fluid-driven fracture propagation in a porous medium is a major computational challenge, with applications in geosciences and engineering. The two main families of modeling approaches are those models that represent fractures as explicit discontinuities and solve the moving boundary problem and those that represent fractures as thin damaged zones, solving a continuum problem throughout. The latter family includes the so-called phase field models. Continuum approaches to fracture face validation and verification challenges, in particular grid convergence, well posedness, and physical relevance in practical scenarios. Here we propose a new quasi-static phase field formulation. The approach fully couples fluid flow in the fracture with deformation and flow in the porous medium, discretizes flow in the fracture on a lower-dimension manifold, and employs the fluid flux between the fracture and the porous solid as coupling variable. We present a numerical assessment of the model by studying the propagation of a fracture in the quarter five-spot configuration. We study the interplay between injection flow rate and rock properties and elucidate fracture propagation patterns under the leak-off toughness dominated regime as a function of injection rate, initial fracture length, and poromechanical properties. For the considered injection scenario, we show that the final fracture length depends on the injection rate, and three distinct patterns are observed. We also rationalize the system response using dimensional analysis to collapse the model results. Finally, we propose some simplifications that alleviate the computational cost of the simulations without significant loss of accuracy.

Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

DOEpatents

Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

2002-01-01

A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

Speciation of chromium (VI) and total chromium determination in welding dust samples by flow-injection analysis coupled to atomic absorption spectrometry.

PubMed

Girard, L; Hubert, J

1996-11-01

We have studied the speciation of chromium (VI) in stainless-steel welding dusts. The approach used for the analysis of Cr(VI) and total Cr relies on a flow-injection analyzer (FIA) equipped with two different sequential detectors. The system measures Cr(VI). by colorimetry (with 1,5-diphenyl carbohydrazide) and total chromium content by flame atomic absorption spectroscopy (AAS). The extraction of the samples of welding-fume dusts is achieved in a buffer solution (acetic acid and sodium acetate at pH 4). This extraction procedure gives a 96% recovery of chromium (VI). The FIA-AAS system that has been described is also more sensitive, has a lower detection limit (0.005 mug ml(-1)) and gives a better precision (< 1%) than other equivalent systems that have been previously described.

Microfluidic model experiments on the injectability of monoclonal antibody solutions

NASA Astrophysics Data System (ADS)

Duchene, Charles; Filipe, Vasco; Nakach, Mostafa; Huille, Sylvain; Lindner, Anke

2017-11-01

Autoinjection devices that allow patients to self-administer medicine are becoming used more frequently; however, this advance comes with an increased need for precision in the injection process. The rare occurrence of protein aggregates in solutions of monoclonal antibodies constitutes a threat to the reliability of such devices. Here we study the flow of protein solutions containing aggregates in microfluidic model systems, mimicking injection devices, to gain fundamental understanding of the catastrophic clogging of constrictions of given size. We form aggregates by mechanically shaking or heating antibody solutions and then inject these solutions into microfluidic channels with varying types of constrictions. Geometrical clogging occurs when aggregates reach the size of the constriction and can in some cases be undone by increasing the applied pressure. We perform systematic experiments varying the relative aggregate size and the flow rate or applied pressure. The mechanical deformation of aggregates during their passage through constrictions is investigated to gain a better understanding of the clogging and unclogging mechanisms.

Preparation, characterization, and application of an enzyme-immobilized magnetic microreactor for flow injection analysis.

PubMed

Nomura, Akira; Shin, Shigemitsu; Mehdi, Othman Oulad; Kauffmann, Jean-Michel

2004-09-15

Enzyme-immobilized magnetic microparticles (EMMP) have been prepared for use as a microreactor in flow injection analysis (FI). The microparticles were directly injected into the FI system. Their retention occurred within the flow line by small permanent magnets located near the detector. The analytical utility of this concept was illustrated by the assay of glucose using glucose oxidase (GOx), immobilized microparticles, and amperometric detection of liberated hydrogen peroxide. The microparticles were derived from silica gel (nominal pore diameter, 15-80 nm) by impregnation with a citric acid/ethanol solution and a ferric nitrate/ethanol solution and then by calcination in a nitrogen atmosphere to produce ferrimagnetic fine particles of spinel-type iron oxide (gamma-Fe(2)O(3)) inside the pore. They were characterized by X-ray diffraction. The calibration curve of the glucose sample (2 microL injected) was linear between 2.5 x 10(-6) and 5 x 10(-4) mol/L (R = 0.9995), and the detection limit was 1.0 x 10(-6) mol/L or 0.36 ng of injected glucose (S/N = 3). The repeatability for a 5 x 10(-4) mol/L glucose solution was RSD = 1.5% (n = 6). Application to the assay of glucose in a fermentation broth is illustrated. The GOx MMP were stable and active for more than eight months when kept at 10 degrees C.

Automated Cell-Cutting for Cell Cloning

NASA Astrophysics Data System (ADS)

Ichikawa, Akihiko; Tanikawa, Tamio; Matsukawa, Kazutsugu; Takahashi, Seiya; Ohba, Kohtaro

We develop an automated cell-cutting technique for cell cloning. Animal cells softened by the cytochalasin treatment are injected into a microfluidic chip. The microfluidic chip contains two orthogonal channels: one microchannel is wide, used to transport cells, and generates the cutting flow; the other is thin and used for aspiration, fixing, and stretching of the cell. The injected cell is aspirated and stretched in the thin microchannel. Simultaneously, the volumes of the cell before and after aspiration are calculated; the volumes are used to calculate the fluid flow required to aspirate half the volume of the cell into the thin microchannel. Finally, we apply a high-speed flow in the orthogonal microchannel to bisect the cell. This paper reports the cutting process, the cutting system, and the results of the experiment.

The determination of levofloxacin by flow injection analysis using UV detection, potentiometry, and conductometry in pharmaceutical preparations.

PubMed

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.

Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system.

PubMed

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.

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection.

PubMed

Yun, Kangsun

2017-10-12

Urinary tract junction obstruction defects are congenital anomalies inducing hydronephrosis and hydroureter. Murine urinary tract junction obstruction defects can be assessed by tracking methylene blue dye flow within the urinary system. Methylene blue dye is injected into the renal pelvis of perinatal embryonic kidneys and dye flow is monitored from the renal pelvis of the kidney through the ureter and into the bladder lumen after applying hydrostatic pressure. Dye accumulation will be evident in the bladder lumen of the normal perinatal urinary tract, but will be constrained between the renal pelvis and the end point of an abnormal ureter, if urinary tract obstructions occur. This method facilitates the confirmation of urinary tract junction obstructions and visualization of hydronephrosis and hydroureter. This manuscript describes a protocol for methylene blue dye injection into the renal pelvis to confirm urinary tract junction obstructions.

A novel flow injection chemiluminescence method for automated and miniaturized determination of phenols in smoked food samples.

PubMed

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.

Using colloidal silica as isolator, diverter and blocking agent for subsurface geological applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourcier, William L.; Roberts, Sarah K.; Roberts, Jeffery J.

A system for blocking fast flow paths in geological formations includes preparing a solution of colloidal silica having a nonviscous phase and a solid gel phase. The solution of colloidal silica is injected into the geological formations while the solution of colloidal silica is in the nonviscous phase. The solution of colloidal silica is directed into the fast flow paths and reaches the solid gel phase in the fast flow paths thereby blocking flow of fluid in the fast paths.

Method and apparatus for controlling cross contamination of microfluid channels

DOEpatents

Hasselbrink, Jr., Ernest F.; Rehm, Jason E [Alameda, CA; Paul, Phillip H [Livermore, CA; Arnold, Don W [Livermore, CA

2006-02-07

A method for controlling fluid flow at junctions in microchannel systems. Control of fluid flow is accomplished generally by providing increased resistance to electric-field and pressure-driven flow in the form of regions of reduced effective cross-sectional area within the microchannels and proximate a channel junction. By controlling these flows in the region of a microchannel junction it is possible to eliminate sample dispersion and cross contamination and inject well-defined volumes of fluid from one channel to another.

Models, data available, and data requirements for estimating the effects of injecting saltwater into disposal wells in the greater Altamont-Bluebell oil and gas field, northern Uinta Basin, Utah

USGS Publications Warehouse

Freethey, Geoffrey W.

1988-01-01

Permits for disposing of salty oil-production water have been issued for 19 wells in the Greater Altamont-Bluebell field. During 1986 more than 500 million gallons of production water were injected into the Duchesne River, Uinta, and Green River Formations through 18 of these wells. The physical and chemical effects of injecting this water into aquifers containing potable water are poorly understood. Interfingering and the structural configuration of these formations add complexity to the description of the geometry and hydrogeology of the ground-water system.A preliminary assessment of the problem indicates that numerical modeling may offer a method of determining the effects of injection. Modeling possibilities include variable-density, three-dimensional flow, sectionaltransport, and areal-transport models. Data needed to develop these models can be derived from a synthesis of geologic, hydrologic, and hydrochemical data already available in the files of State and Federal agencies, oil companies, and private companies. Results from each modeling phase would contribute information for implementing the following phase. The result will be a better understanding of how water moves naturally through the groundwater system, the extent of alterations of both vertical and horizontal flow near the disposal wells, and an overall concept of the effects of deep injection on near-surface aquifers.

Hydraulic and Mechanical Effects from Gas Hydrate Conversion and Secondary Gas Hydrate Formation during Injection of CO2 into CH4-Hydrate-Bearing Sediments

NASA Astrophysics Data System (ADS)

Bigalke, N.; Deusner, C.; Kossel, E.; Schicks, J. M.; Spangenberg, E.; Priegnitz, M.; Heeschen, K. U.; Abendroth, S.; Thaler, J.; Haeckel, M.

2014-12-01

The injection of CO2 into CH4-hydrate-bearing sediments has the potential to drive natural gas production and simultaneously sequester CO2 by hydrate conversion. The process aims at maintaining the in situ hydrate saturation and structure and causing limited impact on soil hydraulic properties and geomechanical stability. However, to increase hydrate conversion yields and rates it must potentially be assisted by thermal stimulation or depressurization. Further, secondary formation of CO2-rich hydrates from pore water and injected CO2 enhances hydrate conversion and CH4 production yields [1]. Technical stimulation and secondary hydrate formation add significant complexity to the bulk conversion process resulting in spatial and temporal effects on hydraulic and geomechanical properties that cannot be predicted by current reservoir simulation codes. In a combined experimental and numerical approach, it is our objective to elucidate both hydraulic and mechanical effects of CO2 injection and CH4-CO2-hydrate conversion in CH4-hydrate bearing soils. For the experimental approach we used various high-pressure flow-through systems equipped with different online and in situ monitoring tools (e.g. Raman microscopy, MRI and ERT). One particular focus was the design of triaxial cell experimental systems, which enable us to study sample behavior even during large deformations and particle flow. We present results from various flow-through high-pressure experimental studies on different scales, which indicate that hydraulic and geomechanical properties of hydrate-bearing sediments are drastically altered during and after injection of CO2. We discuss the results in light of the competing processes of hydrate dissociation, hydrate conversion and secondary hydrate formation. Our results will also contribute to the understanding of effects of temperature and pressure changes leading to dissociation of gas hydrates in ocean and permafrost systems. [1] Deusner C, Bigalke N, Kossel E, Haeckel M. Methane Production from Gas Hydrate Deposits through Injection of Supercritical CO2. Energies 2012:5(7): 2112-2140.

A flow injection chemiluminescence system for the determination of isoniazid.

PubMed

Huang, Y; Zhang, Z; Zhang, D; Lv, J

2000-10-01

A chemiluminescence (CL) flow system is described for the determination of isoniazid based on its enhancement on the chemiluminescence (CL) emission produced upon mixing a hexacyanoferrate(III) solution with an alkaline luminol solution. The system responds linearly to isoniazid concentration in the range 0-1 mg/L with a detection limit (3sigma) of 0.03 microg/L, relative standard deviation (RSD) of 1.2% for 0.1 mg/L isoniazid (n = 11). The system has been successfully applied to the determination of isoniazid in pharmaceutical preparations.

Measurement of the Shear Lift Force on a Bubble in a Channel Flow

NASA Technical Reports Server (NTRS)

Nahra, Henry K.; Motil, Brian; Skor, Mark

2005-01-01

Two-phase flow systems play vital roles in the design of some current and anticipated space applications of two-phase systems which include: thermal management systems, transfer line flow in cryogenic storage, space nuclear power facilities, design and operation of thermal bus, life support systems, propulsion systems, In Situ Resource Utilization (ISRU), and space processes for pharmaceutical applications. The design of two-phase flow systems for space applications requires a clear knowledge of the behaviors of the dispersed phase (bubble), its interaction with the continuous phase (liquid) and its effect on heat and mass transfer processes, The need to understand the bubble generation process arises from the fact that for all space applications, the size and distribution of bubbles are extremely crucial for heat and mass transfer control. One important force in two-phase flow systems is the lift force on a bubble or particle in a liquid shear flow. The shear lift is usually overwhelmed by buoyancy in normal gravity, but it becomes an important force in reduced gravity. Since the liquid flow is usually sheared because of the confining wall, the trajectories of bubbles and particles injected into the liquid flow are affected by the shear lift in reduced gravity. A series of experiments are performed to investigate the lift force on a bubble in a liquid shear flow and its effect on the detachment of a bubble from a wall under low gravity conditions. Experiments are executed in a Poiseuille flow in a channel. An air-water system is used in these experiments that are performed in the 2.2 second drop tower. A bubble is injected into the shear flow from a small injector and the shear lift is measured while the bubble is held stationary relative to the fluid. The trajectory of the bubble prior, during and after its detachment from the injector is investigated. The measured shear lift force is calculated from the trajectory of the bubble at the detachment point. These values for the shear lift are then compared with the theoretical predictions from various published works on shear lift in the open literature, which include asymptotic solutions at low bubble Reynolds number, potential flow predictions and numerical studies that deal with intermediate bubble Reynolds numbers.

Influences of Detection Pinhole and Sample Flow on Thermal Lens Detection in Microfluidic Systems

NASA Astrophysics Data System (ADS)

Liu, Mingqiang; Franko, Mladen

2014-12-01

Thermal lens microscopy (TLM), due to its high temporal () and spatial resolution (), has been coupled to lab-on-chip chemistry for detection of a variety of compounds in chemical or biological fields. Due to the very short optical path length (usually below 100 ) in a microchip, the sensitivity of TLM is unfortunately still 10 to 100 times lower than conventional TLS with 1 cm sample length. Optimization of the TLM optical configuration was made with respect to different pinhole aperture-to-beam size ratios for the best signal-to-noise ratio. In the static mode, the instrumental noise comes mainly from the shot noise of the probe beam when the chopper frequency is over 1 kHz or from the flicker noise of the probe beam at low frequencies. In the flowing mode, the flow-induced noise becomes dominant when the flow rate is high. At a given flow rate, fluids with a higher density and/or a higher viscosity will cause larger flow-induced noise. As an application, a combined microfluidic flow injection analysis ()-TLM device was developed for rapid determination of pollutants by colorimetric reactions. Hexavalent chromium [Cr(VI)] was measured as a model analyte. Analytical signals for 12 sample injections in 1 min have been recorded by the FIA-TLM. For injections of sub-L samples into the microfluidic stream in a deep microchannel, a limit of detection of was achieved for Cr(VI) in water at 60 mW excitation power.

Stationary to nonstationary transition in crossed-field devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marini, Samuel; Rizzato, Felipe B.; Pakter, Renato

2016-03-15

The previous results based on numerical simulations showed that a cold electron beam injected in a crossed field gap does not reach a time independent stationary state in the space charge limited regime [P. J. Christenson and Y. Y. Lau, Phys. Plasmas 1, 3725 (1994)]. In this work, the effect of finite injection temperature in the transition from stationary to nonstationary states is investigated. A fully kinetic model for the electron flow is derived and used to determine the possible stationary states of the system. It is found that although there is always a stationary solution for any set ofmore » parameters, depending on the injection temperature the electron flow becomes very sensitive to fluctuations and the stationary state is never reached. By investigating the nonlinear dynamics of a characteristic electron, a theory based on a single free parameter is constructed to predict when the transition between stationary and nonstationary states occurs. In agreement with the previous numerical results, the theory indicates that for vanishing temperatures the system never reaches the time independent stationary state in the space charge limited regime. Nevertheless, as the injection temperature is raised it is found a broad range of system parameters for which the stationary state is indeed attained. By properly adjusting the free parameter in the theory, one can be able to describe, to a very good accuracy, when the transition occurs.« less

Feasibility of utilizing bioindicators for testing microbial inactivation in sweetpotato purees processed with a continuous-flow microwave system.

PubMed

Brinley, T A; Dock, C N; Truong, V-D; Coronel, P; Kumar, P; Simunovic, J; Sandeep, K P; Cartwright, G D; Swartzel, K R; Jaykus, L-A

2007-06-01

Continuous-flow microwave heating has potential in aseptic processing of various food products, including purees from sweetpotatoes and other vegetables. Establishing the feasibility of a new processing technology for achieving commercial sterility requires evaluating microbial inactivation. This study aimed to assess the feasibility of using commercially available plastic pouches of bioindicators containing spores of Geobacillius stearothermophilus ATCC 7953 and Bacillus subtilis ATCC 35021 for evaluating the degree of microbial inactivation achieved in vegetable purees processed in a continuous-flow microwave heating unit. Sweetpotato puree seeded with the bioindicators was subjected to 3 levels of processing based on the fastest particles: undertarget process (F(0) approximately 0.65), target process (F(0) approximately 2.8), and overtarget process (F(0) approximately 10.10). After initial experiments, we found it was necessary to engineer a setup with 2 removable tubes connected to the continuous-flow microwave system to facilitate the injection of indicators into the unit without interrupting the puree flow. Using this approach, 60% of the indicators injected into the system could be recovered postprocess. Spore survival after processing, as evaluated by use of growth indicator dyes and standard plating methods, verified inactivation of the spores in sweetpotato puree. The log reduction results for B. subtilis were equivalent to the predesigned degrees of sterilization (F(0)). This study presents the first report suggesting that bioindicators such as the flexible, food-grade plastic pouches can be used for microbial validation of commercial sterilization in aseptic processing of foods using a continuous-flow microwave system.

Critical fiber length technique for composite manufacturing processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivley, G.N.; Vandiver, T.L.; Dougherty, N.S.

1996-12-31

An improved injection technique for composite structures has been cooperatively developed by the U.S. Army Missile Command (MICOM) and Rockwell International (RI). This process simultaneously injects chopped fiberglass fibers and an epoxy resin matrix into a mold. Four injection techniques: (1){open_quotes}Little Willie{close_quotes} RTM system, (2) Pressure Vat system, (3) Pressure Vat system with vacuum assistance, and (4) Injection gun system, were investigated for use with a 304.8 mm x 304.8 mm x 5.08 mm (12 in x 12 in x 0.2 in) flat plaque mold. The driving factors in the process optimization included: fiber length, fiber weight, matrix viscosity, injectionmore » pressure, flow rate, and tool design. At fiber weights higher than 30 percent, the injection gun appears to have advantages over the other systems investigated. Results of an experimental investigation are reviewed in this paper. The investigation of injection techniques is the initial part of the research involved in a developing process, {open_quotes}Critical Fiber Length Technique{close_quotes}. This process will use the data collected in injection experiment along with mechanical properties derived from coupon test data to be incorporated into a composite material design code. The {open_quotes}Critical Fiber Length Technique{close_quotes} is part of a Cooperative Research and Development Agreement (CRADA) established in 1994 between MICOM and RI.« less

Automatic amino acid analyzer

NASA Technical Reports Server (NTRS)

Berdahl, B. J.; Carle, G. C.; Oyama, V. I.

1971-01-01

Analyzer operates unattended or up to 15 hours. It has an automatic sample injection system and can be programmed. All fluid-flow valve switching is accomplished pneumatically from miniature three-way solenoid pilot valves.

Summary and interpretation of dye-tracer tests to investigate the hydraulic connection of fractures at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Kentucky

USGS Publications Warehouse

Taylor, Charles J.

1994-01-01

Dye-tracer tests were done during 1985-92 to investigate the hydraulic connection between fractures in Pennsylvanian coal-bearing strata at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Ky. Fluorescent dye was injected into a core hole penetrating near-surface and mining-induced fractures near the crest of the ridge. The rate and direction of migration of dye in the subsurface were determined by measuring the relative concentration of dye in water samples collected from piezometers completed in conductive fracture zones and fractured coal beds at various stratigraphic horizons within the ridge. Dye-concentration data and water-level measurements for each piezometer were plotted as curves on dye-recovery hydrographs. The dye-recovery hydrographs were used to evaluate trends in the fluctuation of dye concentrations and hydraulic heads in order to identify geologic and hydrologic factors affecting the subsurface transport of dye. The principal factors affecting the transport of dye in the subsurface hydrologic system were determined to be (1) the distribution, interconnection, and hydraulic properties of fractures; (2) hydraulic-head conditions in the near-fracture zone at the time of dye injection; and (3) subsequent short- and long-term fluctuations in recharge to the hydrologic system. In most of the dye-tracer tests, dye-recovery hydrographs are characterized by complex, multipeaked dye-concentration curves that are indicative of a splitting of dye flow as ground water moved through fractures. Intermittent dye pulses (distinct upward spikes in dye concentration) mark the arrivals of dye-labeled water to piezometers by way of discrete fracture-controlled flow paths that vary in length, complexity, and hydraulic conductivity. Dye injections made during relatively high- or increasinghead conditions resulted in rapid transport of dye (within several days or weeks) from near-surf ace fractures to piezometers. Injections made during relatively low- or decreasing-head conditions resulted in dye being trapped in hydraulically dead zones in water-depleted fractures. Residual dye was remobilized from storage and transported (over periods ranging from several months to about 2 years) by increased recharge to the hydrologic system. Subsequent fluctuations in hydraulic gradients, resulting from increases or decreases in recharge to the hydrologic system, acted to speed or slow the transport of dye along the fracture-controlled flow paths. The dye-tracer tests also demonstrated that mining-related disturbances significantly altered the natural fracture-controlled flow paths of the hydrologic system over time. An abandoned underground mine and subsidence-related surface cracks extend to within 250 ft of the principal dye-injection core hole. Results from two of the dye-tracer tests at the site indicate that the annular seal in the core hole was breached by subsurface propagation of the mining-induced fractures. This propagation of fractures resulted in hydraulic short-circuiting between the dye-injection zone in the core hole and two lower piezometer zones, and a partial disruption of the hydraulic connection between the injection core hole and downgradient piezometers on the ridge crest and valley wall. In addition, injected dye was detected in piezometers monitoring a flooded part of the abandoned underground mine. Dye was apparently transported into the mine through a hydraulic connection between the injection core hole and subsidence-related fractures.

10 CFR Appendix E to Part 50 - Emergency Planning and Preparedness for Production and Utilization Facilities

Code of Federal Regulations, 2011 CFR

2011-01-01

... could communicate with a safety system. In this case, appropriate isolation devices would be required at..., feedwater flow, and reactor power; (2) Safety injection: Reactor core isolation cooling flow, high-pressure... data points identified in the ERDS Data Point Library 9 (site specific data base residing on the ERDS...

10 CFR Appendix E to Part 50 - Emergency Planning and Preparedness for Production and Utilization Facilities

Code of Federal Regulations, 2010 CFR

2010-01-01

... could communicate with a safety system. In this case, appropriate isolation devices would be required at..., feedwater flow, and reactor power; (2) Safety injection: Reactor core isolation cooling flow, high-pressure... data points identified in the ERDS Data Point Library 9 (site specific data base residing on the ERDS...

A bioconvection model for a squeezing flow of nanofluid between parallel plates in the presence of gyrotactic microorganisms

NASA Astrophysics Data System (ADS)

Bin-Mohsin, Bandar; Ahmed, Naveed; Adnan; Khan, Umar; Tauseef Mohyud-Din, Syed

2017-04-01

This article deals with the bioconvection flow in a parallel-plate channel. The plates are parallel and the flowing fluid is saturated with nanoparticles, and water is considered as a base fluid because microorganisms can survive only in water. A highly nonlinear and coupled system of partial differential equations presenting the model of bioconvection flow between parallel plates is reduced to a nonlinear and coupled system (nondimensional bioconvection flow model) of ordinary differential equations with the help of feasible nondimensional variables. In order to find the convergent solution of the system, a semi-analytical technique is utilized called variation of parameters method (VPM). Numerical solution is also computed and the Runge-Kutta scheme of fourth order is employed for this purpose. Comparison between these solutions has been made on the domain of interest and found to be in excellent agreement. Also, influence of various parameters has been discussed for the nondimensional velocity, temperature, concentration and density of the motile microorganisms both for suction and injection cases. Almost inconsequential influence of thermophoretic and Brownian motion parameters on the temperature field is observed. An interesting variation are inspected for the density of the motile microorganisms due to the varying bioconvection parameter in suction and injection cases. At the end, we make some concluding remarks in the light of this article.

Selective sequential precipitation of dissolved metals in mine drainage from coal mine

NASA Astrophysics Data System (ADS)

Yim, Giljae; Bok, Songmin; Ji, Sangwoo; Oh, Chamteut; Cheong, Youngwook; Han, Youngsoo; Ahn, Joosung

2017-04-01

In abandoned mines in Korea, a large amount of mine drainage continues to flow out and spread pollution. In purification of the mine drainage a massive amount of sludge is generated as waste. Since this metal sludge contains high Fe, Al and Mn oxides, developing the treatment method to recover homogeneous individual metal with high purity may beneficial to recycle waste metals as useful resources and reduce the amount of sludge production. In this regard, we established a dissolved metals selective precipitation process to treat Waryong Industry's mine drainage. The process that selectively precipitates metals dissolved in mine drainage is a continuous Fe-buffer-Al process, and each process consists of the neutralization tank, the coagulation tank, and the settling tank. Based on this process, this study verified the operational applicability of the Fe and Al selective precipitation. Our previous study revealed that high-purity Fe and Al precipitates could be recovered at a flow rate of 1.5 ton/day, while the lower purity was achieved when the rate was increased to about 3 ton/day due to the difficulty in reagent dosage control. In the current study was conducted to increase the capacity of the system to recover Fe and Al as high-purity precipitates at a flow rate of 10 ton/day with the ensured continuous operations by introducing an automatic reagent injection system. The previous study had a difficulty in controlling the pH and operating system continuously due to the manually controlled reagent injection system. To upgrade this and ensure the optimal pH in a stable way, a continuous reagent injection system was installed. The result of operation of the 10 ton/day system confirmed that the scaled-up process could maintain the stable recovery rates and purities of precipitates on site.

Computational analysis of stall and separation control in centrifugal compressors

NASA Astrophysics Data System (ADS)

Stein, Alexander

2000-10-01

A numerical technique for simulating unsteady viscous fluid flow in turbomachinery components has been developed. In this technique, the three-dimensional form of the Reynolds averaged Navier-Stokes equations is solved in a time-accurate manner. The flow solver is used to study fluid dynamic phenomena that lead to instabilities in centrifugal compressors. The results indicate that large flow incidence angles, at reduced flow rates, can cause boundary layer separation near the blade leading edge. This mechanism is identified as the primary factor in the stall inception process. High-pressure jets upstream of the compressor face are studied as a means of controlling compressor instabilities. Steady jets are found to alter the leading edge flow pattern and effectively suppress compressor instabilities. Yawed jets are more effective than parallel jets and an optimum yaw angle exists for each compression system. Numerical simulations utilizing pulsed jets have also been done. Pulsed jets are found to yield additional performance enhancements and lead to a reduction in external air requirements for operating the jets. Jets pulsed at higher frequencies perform better than low-frequency jets. These findings suggest that air injection is a viable means of alleviating compressor instabilities and could impact gas turbine technology. Results concerning the optimization of practical air injection systems and implications for future research are discussed. The flow solver developed in this work, along with the postprocessing tools developed to interpret the results, provide a rational framework for analyzing and controlling current and next generation compression systems.

Modeling of time-lapse multi-scale seismic monitoring of CO2 injected into a fault zone to enhance the characterization of permeability in enhanced geothermal systems

NASA Astrophysics Data System (ADS)

Zhang, R.; Borgia, A.; Daley, T. M.; Oldenburg, C. M.; Jung, Y.; Lee, K. J.; Doughty, C.; Altundas, B.; Chugunov, N.; Ramakrishnan, T. S.

2017-12-01

Subsurface permeable faults and fracture networks play a critical role for enhanced geothermal systems (EGS) by providing conduits for fluid flow. Characterization of the permeable flow paths before and after stimulation is necessary to evaluate and optimize energy extraction. To provide insight into the feasibility of using CO2 as a contrast agent to enhance fault characterization by seismic methods, we model seismic monitoring of supercritical CO2 (scCO2) injected into a fault. During the CO2 injection, the original brine is replaced by scCO2, which leads to variations in geophysical properties of the formation. To explore the technical feasibility of the approach, we present modeling results for different time-lapse seismic methods including surface seismic, vertical seismic profiling (VSP), and a cross-well survey. We simulate the injection and production of CO2 into a normal fault in a system based on the Brady's geothermal field and model pressure and saturation variations in the fault zone using TOUGH2-ECO2N. The simulation results provide changing fluid properties during the injection, such as saturation and salinity changes, which allow us to estimate corresponding changes in seismic properties of the fault and the formation. We model the response of the system to active seismic monitoring in time-lapse mode using an anisotropic finite difference method with modifications for fracture compliance. Results to date show that even narrow fault and fracture zones filled with CO2 can be better detected using the VSP and cross-well survey geometry, while it would be difficult to image the CO2 plume by using surface seismic methods.

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

NASA Astrophysics Data System (ADS)

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

2015-12-01

The GWHP system uses a stable temperature of groundwater for cooling and heating in buildings and thus has been known as one of the most energy-saving and cost-efficient renewable energy techniques. A GWHP facility was installed at an island located at the confluence of North Han and South Han rivers, Korea. Because of well-developed alluvium, the aquifer is suitable for application of this system, extracting and injecting a large amount of groundwater. However, the numerical experiments under various operational conditions showed that it could be vulnerable to thermal interference due to the highly permeable gravel layer, as a preferential path of thermal plume migration, and limited space for well installation. Thus, regional groundwater flow must be an important factor of consideration for the efficient operation under these conditions but was found to be not simple in this site. While the groundwater level in this site totally depends on the river stage control of Paldang dam, the direction and velocity of the regional groundwater flow, observed using the colloidal borescope, have been changed hour by hour with the combined flows of both the rivers. During the pumping and injection tests, the water discharges in Cheongpyeong dam affected their respective results. Moreover, the measured NO3-N concentrations might imply the effect of agricultural activities around the facility on the groundwater quality along the regional flow. It is obvious that the extraction and injection of groundwater during the facility operation will affect the fate of the agricultural contaminants. Particularly, the gravel layer must also be a main path for contaminant migration. The simulations for contaminant transport during the facility operation showed that the operation strategy for only thermal efficiency could be unsafe and unstable in respect of groundwater quality. All these results concluded that the integrated approach on groundwater flow and heat/solute transport is necessary for the sustainable GWHP system operation. Acknowledgment: This work was supported by the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+)" in "Water Resources Management Program (code 11 Technology Innovation C05)" of the MOLIT and the KAIA in Korea.

Unsteady boundary-layer injection

NASA Technical Reports Server (NTRS)

Telionis, D. P.; Jones, G. S.

1981-01-01

The boundary-layer equations for two-dimensional incompressible flow are integrated numerically for the flow over a flat plate and a Howarth body. Injection is introduced either impulsively or periodically along a narrow strip. Results indicate that injection perpendicular to the wall is transmitted instantly across the boundary layer and has little effect on the velocity profile parallel to the wall. The effect is a little more noticeable for flows with adverse pressure gradients. Injection parallel to the wall results in fuller velocity profiles. Parallel and oscillatory injection appears to influence the mean. The amplitude of oscillation decreases with distance from the injection strip but further downstream it increases again in a manner reminiscent of an unstable process.

Influence of G-jitter on the characteristics of a non-premixed flame: Experimental approach

NASA Astrophysics Data System (ADS)

Joulain, Pierre; Cordeiro, Pierre; Rouvreau, Sébastien; Legros, Guillaume; Fuentes, Andres; Torero, José L.

2005-03-01

The combustion of a flat plate in a boundary layer under microgravity conditions, which was first described by Emmons, is studied using a gas burner. Magnitude of injection and blowing velocities are chosen to be characteristic of pyrolyzing velocity of solid fuels, and of ventilation systems in space stations. These velocities are about 0.1 m/s for oxidiser flow and 0.004m/s for fuel flow. In this configuration, flame layout results from a coupled interaction between oxidiser flow, fuel flow and thermal expansion. Influences of these parameters are studied experimentally by means of flame length and standoff distance measurements using CH* chemiluminescence's and visible emission of the flame. Flow was also studied with Particle Image Velocimetry (PIV). Inert flows, with and without injection, and reacting flow in a microgravity environment were considered to distinguish aerodynamic from thermal effect. Thermal expansion effects have been shown by means of the acceleration of oxidiser flow. Three-dimensional effects, which are strongly marked for high injection velocities were studied. Three-dimensional tools adaptability to parabolic flights particular conditions were of concern. Flame sensitivity to g-jitters was investigated according to g-jitters frequency and range involved by parabolic flights. It appears that flame location (standoff distance), flame characteristics (length, thickness, brightness) and the aerodynamic field of the low velocity reacting flow are very much affected by the fluctuation of the gravity level or g-jitter. The lower the g-jitter frequency is, the higher the perturbation. Consequently it is difficult to perform relevant experiments for a main flow velocity lower than 0.05m/s. DNS calculations confirm the present observations, but most of the results are presented elsewhere.

Low cost solar array project silicon materials task. Development of a process for high capacity arc heater production of silicon for solar arrays

NASA Technical Reports Server (NTRS)

Reed, W. H.

1978-01-01

Silicon tetrachloride and a reductant (sodium) will be injected into an arc heated mixture of hydrogen and argon, yielding silicon and gaseous sodium chloride. Detailed characterization of the Sonicore sodium injection nozzle, using water as the test fluid was completed. Results indicated that flow rates of 45 gph sodium and 50 scfm argon should produce sufficiently small droplet sizes. The design effort was also completed for the test system preparation which was divided into two categories: (1) system components and (2) test system-laboratory integration.

Advanced Design Features of APR1400 and Realization in Shin Kori Construction Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

OH, S.J.; Park, K.C.; Kim, H.G.

2006-07-01

APR1400 adopted several advanced design features. To ensure their proper operation as a part of ShinKori 3,4 project, both experimental and analytical work are continuing. In this paper, work on the advanced design features related to enhanced safety is examined. APR1400 safety injection system consists of four independent trains which include four safety injection pump and tanks. A passive flow regulating device called fluidic device is installed in the safety injection tanks. Separate effect tests including a full scale fluidic device tests have been conducted. Integral system tests are in progress. Combination of these work with the analytical work usingmore » RELAP5/Mod3 would ensure the proper operation of the new safety injection systems. To mitigate severe accidents, hydrogen mitigation system using PARs and igniters is adopted. Also, active injection system and the streamlined insulation design are adopted to enhance the in-vessel retention capability with the external cooling of RPV strategy. Analytic work with supporting experiments is performed. We are certain that these preparatory work would help the successful adaptation of ADF in ShinKori project. (authors)« less

Reduction of Altitude Diffuser Jet Noise Using Water Injection

NASA Technical Reports Server (NTRS)

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

2014-01-01

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.

Reduction of Altitude Diffuser Jet Noise Using Water Injection

NASA Technical Reports Server (NTRS)

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.

A qualitative view of cryogenic fluid injection into high speed flows

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Schlumberger, J.; Proctor, M.

1991-01-01

The injection of supercritical pressure, subcritical temperature fluids, into a 2-D, ambient, static temperature and static pressure supersonic tunnel and free jet supersonic nitrogen flow field was observed. Observed patterns with fluid air were the same as those observed for fluid nitrogen injected into the tunnel at 90 deg to the supersonic flow. The nominal injection pressure was of 6.9 MPa and tunnel Mach number was 2.7. When injected directly into and opposing the tunnel exhaust flow, the observed patterns with fluid air were similar to those observed for fluid nitrogen but appeared more diffusive. Cryogenic injection creates a high density region within the bow shock wake but the standoff distance remains unchanged from the gaseous value. However, as the temperature reaches a critical value, the shock faded and advanced into the supersonic stream. For both fluids, nitrogen and air, the phenomena was completely reversible.

PAB3D Simulations of a Nozzle with Fluidic Injection for Yaw Thrust-Vector Control

NASA Technical Reports Server (NTRS)

Deere, Karen A.

1998-01-01

An experimental and computational study was conducted on an exhaust nozzle with fluidic injection for yaw thrust-vector control. The nozzle concept was tested experimentally in the NASA Langley Jet Exit Test Facility (JETF) at nozzle pressure ratios up to 4 and secondary fluidic injection flow rates up to 15 percent of the primary flow rate. Although many injection-port geometries and two nozzle planforms (symmetric and asymmetric) were tested experimentally, this paper focuses on the computational results of the more successful asymmetric planform with a slot injection port. This nozzle concept was simulated with the Navier-Stokes flow solver, PAB3D, invoking the Shih, Zhu, and Lumley algebraic Reynolds stress turbulence model (ASM) at nozzle pressure ratios (NPRs) of 2,3, and 4 with secondary to primary injection flow rates (w(sub s)/w(sub p)) of 0, 2, 7 and 10 percent.

Impulsive Injection for Compressor Stator Separation Control

NASA Technical Reports Server (NTRS)

Culley, Dennis E.; Braunscheidel, Edward P.; Bright, Michelle M.

2005-01-01

Flow control using impulsive injection from the suction surface of a stator vane has been applied in a low speed axial compressor. Impulsive injection is shown to significantly reduce separation relative to steady injection for vanes that were induced to separate by an increase in vane stagger angle of 4 degrees. Injected flow was applied to the airfoil suction surface using spanwise slots pitched in the streamwise direction. Injection was limited to the near-hub region, from 10 to 36 percent of span, to affect the dominant loss due to hub leakage flow. Actuation was provided externally using high-speed solenoid valves closely coupled to the vane tip. Variations in injected mass, frequency, and duty cycle are explored. The local corrected total pressure loss across the vane at the lower span region was reduced by over 20 percent. Additionally, low momentum fluid migrating from the hub region toward the tip was effectively suppressed resulting in an overall benefit which reduced corrected area averaged loss through the passage by 4 percent. The injection mass fraction used for impulsive actuation was typically less than 0.1 percent of the compressor through flow.

Model Scramjet Inlet Unstart Induced by Mass Addition and Heat Release

NASA Astrophysics Data System (ADS)

Im, Seong-Kyun; Baccarella, Damiano; McGann, Brendan; Liu, Qili; Wermer, Lydiy; Do, Hyungrok

2015-11-01

The inlet unstart phenomena in a model scramjet are investigated at an arc-heated hypersonic wind tunnel. The unstart induced by nitrogen or ethylene jets at low or high enthalpy Mach 4.5 freestream flow conditions are compared. The jet injection pressurizes the downstream flow by mass addition and flow blockage. In case of the ethylene jet injection, heat release from combustion increases the backpressure further. Time-resolved schlieren imaging is performed at the jet and the lip of the model inlet to visualize the flow features during unstart. High frequency pressure measurements are used to provide information on pressure fluctuation at the scramjet wall. In both of the mass and heat release driven unstart cases, it is observed that there are similar flow transient and quasi-steady behaviors of unstart shockwave system during the unstart processes. Combustion driven unstart induces severe oscillatory flow motions of the jet and the unstart shock at the lip of the scramjet inlet after the completion of the unstart process, while the unstarted flow induced by solely mass addition remains relatively steady. The discrepancies between the processes of mass and heat release driven unstart are explained by flow choking mechanism.

Flow Rates Measurement and Uncertainty Analysis in Multiple-Zone Water-Injection Wells from Fluid Temperature Profiles

PubMed Central

Reges, José E. O.; Salazar, A. O.; Maitelli, Carla W. S. P.; Carvalho, Lucas G.; Britto, Ursula J. B.

2016-01-01

This work is a contribution to the development of flow sensors in the oil and gas industry. It presents a methodology to measure the flow rates into multiple-zone water-injection wells from fluid temperature profiles and estimate the measurement uncertainty. First, a method to iteratively calculate the zonal flow rates using the Ramey (exponential) model was described. Next, this model was linearized to perform an uncertainty analysis. Then, a computer program to calculate the injected flow rates from experimental temperature profiles was developed. In the experimental part, a fluid temperature profile from a dual-zone water-injection well located in the Northeast Brazilian region was collected. Thus, calculated and measured flow rates were compared. The results proved that linearization error is negligible for practical purposes and the relative uncertainty increases as the flow rate decreases. The calculated values from both the Ramey and linear models were very close to the measured flow rates, presenting a difference of only 4.58 m³/d and 2.38 m³/d, respectively. Finally, the measurement uncertainties from the Ramey and linear models were equal to 1.22% and 1.40% (for injection zone 1); 10.47% and 9.88% (for injection zone 2). Therefore, the methodology was successfully validated and all objectives of this work were achieved. PMID:27420068

Heat-exchanger concepts for neutral-beam calorimeters

NASA Astrophysics Data System (ADS)

Thompson, C. C.; Polk, D. H.; McFarlin, D. J.; Stone, R.

1981-10-01

Advanced cooling concepts that permit the design of water cooled heat exchangers for use as calorimeters and beam dumps for advanced neutral beam injection systems were evaluated. Water cooling techniques ranging from pool boiling to high pressure, high velocity swirl flow were considered. Preliminary performance tests were carried out with copper, inconel and molybdenum tubes ranging in size from 0.19 to 0.50 in. diameter. Coolant flow configurations included: (1) smooth tube/straight flow; (2) smooth tube with swirl flow created by tangential injection of the coolant; and (3) axial flow in internally finned tubes. Additionally, the effect of tube L/D was evaluated. A CO2 laser was employed to irradiate a sector of the tube exterior wall; the laser power was incrementally increased until burnout occurred. Absorbed heat fluxes were calculated by dividing the measured coolant heat load by the area of the burn spot on the tube surface. Two six element thermopiles were used to accurately determine the coolant temperature rise. A maximum burnout heat flux near 14 kW/sq cm was obtained for the molybdenum tube swirl flow configuration.

Geo-Hydro Statistical Characterization of Preferential Flow and Transport Processes in Karst Groundwater Systems

NASA Astrophysics Data System (ADS)

Anaya, A. A.; Padilla, I. Y.; Macchiavelli, R. E.

2011-12-01

Karst groundwater systems are highly productive and provide an important fresh water resource for human development and ecological integrity. Their high productivity is often associated with conduit flow and high matrix permeability. The same characteristics that make these aquifers productive also make them highly vulnerable to contamination and a likely for contaminant exposure. Of particular interest are chlorinated organic contaminants and phthalates derived from industrial solvents and plastic by-products. These chemicals have been identified as potential precursors of pre-term birth, a leading cause of neonatal complications with a significant health and societal cost. The general objectives of this work are to: (1) develop fundamental knowledge and determine the processes controlling the release, mobility, persistence, and possible pathways of contaminants in karst groundwater systems, and (2) characterize transport processes in conduit and diffusion-dominated flow under base flow and storm flow conditions. The work presented herein focuses on the development of geo-hydro statistical tools to characterize flow and transport processes under different flow regimes. Multidimensional, laboratory-scale Geo-Hydrobed models were developed and tested for this purpose. The models consist of stainless-steel tanks containing karstified limestone blocks collected from the karst aquifer formation of northern Puerto Rico. The models a network of sampling wells to monitor flow, pressure, and solute concentrations temporally and spatially. Experimental work entailed making a series of point injections in wells while monitoring the hydraulic response in other wells. Statistical mixed models were applied to spatial probabilities of hydraulic response and weighted injected volume data, and were used to determinate the best spatial correlation structure to represent paths of preferential flow in the limestone units under different groundwater flow regimes. Preliminary testing of the karstified models show that the system can be used to represent the variable transport regime characterized by conduit and diffuses flow in the karst systems. Initial hydraulic characterization indicates a highly heterogeneous system resulting in large preferential flow components. Future works involve characterization of dual porosity system using conservative tracers, fate and transport experiments using phthalates and chlorinated solvents, geo-temporal statistical modeling, and the testing of "green" remediation technologies in karst groundwater. This work is supported by the U.S. Department of Energy, Savannah River (Grant Award No. DE-FG09-07SR22571), and the National Institute of Environmental Health Sciences (NIEHS, Grant Award No. P42ES017198).

Analytical solutions to non-Fickian subsurface dispersion in uniform groundwater flow

USGS Publications Warehouse

Zou, S.; Xia, J.; Koussis, Antonis D.

1996-01-01

Analytical solutions are obtained by the Fourier transform technique for the one-, two-, and three-dimensional transport of a conservative solute injected instantaneously in a uniform groundwater flow. These solutions account for dispersive non-linearity caused by the heterogeneity of the hydraulic properties of aquifer systems and can be used as building blocks to construct solutions by convolution (principle of superposition) for source conditions other than slug injection. The dispersivity is assumed to vary parabolically with time and is thus constant for the entire system at any given time. Two approaches for estimating time-dependent dispersion parameters are developed for two-dimensional plumes. They both require minimal field tracer test data and, therefore, represent useful tools for assessing real-world aquifer contamination sites. The first approach requires mapped plume-area measurements at two specific times after the tracer injection. The second approach requires concentration-versus-time data from two sampling wells through which the plume passes. Detailed examples and comparisons with other procedures show that the methods presented herein are sufficiently accurate and easier to use than other available methods.

Numerical Modeling of Gas and Water Flow in Shale Gas Formations with a Focus on the Fate of Hydraulic Fracturing Fluid.

PubMed

Edwards, Ryan W J; Doster, Florian; Celia, Michael A; Bandilla, Karl W

2017-12-05

Hydraulic fracturing in shale gas formations involves the injection of large volumes of aqueous fluid deep underground. Only a small proportion of the injected water volume is typically recovered, raising concerns that the remaining water may migrate upward and potentially contaminate groundwater aquifers. We implement a numerical model of two-phase water and gas flow in a shale gas formation to test the hypothesis that the remaining water is imbibed into the shale rock by capillary forces and retained there indefinitely. The model includes the essential physics of the system and uses the simplest justifiable geometrical structure. We apply the model to simulate wells from a specific well pad in the Horn River Basin, British Columbia, where there is sufficient available data to build and test the model. Our simulations match the water and gas production data from the wells remarkably closely and show that all the injected water can be accounted for within the shale system, with most imbibed into the shale rock matrix and retained there for the long term.

An automated method of on-line extraction coupled with flow injection and capillary electrophoresis for phytochemical analysis.

PubMed

Chen, Hongli; Ding, Xiuping; Wang, Min; Chen, Xingguo

2010-11-01

In this study, an automated system for phytochemical analysis was successfully fabricated for the first time in our laboratory. The system included on-line decocting, filtering, cooling, sample introducing, separation, and detection, which greatly simplified the sample preparation and shortened the analysis time. Samples from the decoction extract were drawn every 5 min through an on-line filter and a condenser pipe to the sample loop from which 20-μL samples were injected into the running buffer and transported into a split-flow interface coupling the flow injection and capillary electrophoresis systems. The separation of glycyrrhetinic acid (GTA) and glycyrrhizic acid (GA) took less than 5 min by using a 10 mM borate buffer (adjusted pH to 8.8) and +10 kV voltage. Calibration curves showed good linearity with correlation coefficients (R) more than 0.9991. The intra-day repeatabilities (n = 5, expressed as relative standard deviation) of the proposed system, obtained using GTA and GA standards, were 1.1% and 0.8% for migration time and 0.7% and 0.9% for peak area, respectively. The mean recoveries of GTA and GA in the off-line extract of Glycyrrhiza uralensis Fisch root were better than 99.0%. The limits of detection (signal-to-noise ratio = 3) of the proposed method were 6.2 μg/mL and 6.9 μg/mL for GTA and GA, respectively. The dynamic changes of GTA and GA on the decoction time were obtained during the on-line decoction process of Glycyrrhiza uralensis Fisch root.

Numerical Simulations of Helicity Condensation in the Solar Corona

NASA Technical Reports Server (NTRS)

Zhao, L.; DeVore, C. R.; Antiochos, S. K.; Zurbuchen, T. H.

2015-01-01

The helicity condensation model has been proposed by Antiochos (2013) to explain the observed smoothness of coronal loops and the observed buildup of magnetic shear at filament channels. The basic hypothesis of the model is that magnetic reconnection in the corona causes the magnetic stress injected by photospheric motions to collect only at those special locations where prominences form. In this work we present the first detailed quantitative MHD simulations of the reconnection evolution proposed by the helicity condensation model. We use the well-known ansatz of modeling the closed corona as an initially uniform field between two horizontal photospheric plates. The system is driven by applying photospheric rotational flows that inject magnetic helicity into the system. The flows are confined to a finite region on the photosphere so as to mimic the finite flux system of, for example, a bipolar active region. The calculations demonstrate that, contrary to common belief, coronal loops having opposite helicity do not reconnect, whereas loops having the same sense of helicity do reconnect. Furthermore, we find that for a given amount of helicity injected into the corona, the evolution of the magnetic shear is insensitive to whether the pattern of driving photospheric motions is fixed or quasi-random. In all cases, the shear propagates via reconnection to the boundary of the flow region while the total magnetic helicity is conserved, as predicted by the model. We discuss the implications of our results for solar observations and for future, more realistic simulations of the helicity condensation process.

Coherent Anti-Stokes Raman Spectroscopy (CARS) Measurements in Supersonic Combustors at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Danehy, Paul M.; OByrne, Sean B.; Tedder, Sarah A.; Cutler, Andrew D.

2005-01-01

This paper describes the recent use of coherent anti-Stokes Raman spectroscopy (CARS) to study supersonic combustion at NASA Langley Research Center. CARS is a nonlinear optical measurement technique used to measure temperature and species mole fractions remotely in harsh environments. A CARS system has been applied to two different combustor geometries at NASA Langley. Both experiments used the same vitiated wind-tunnel facility to create an air flow that simulates flight at Mach numbers of 6 and 7 for the combustor inlet and both experiments used hydrogen fuel. In the first experiment, the hydrogen was injected supersonically at a 30-degree angle with respect to the incoming flow. In the second experiment, the hydrogen was injected sonically at normal incidence. While these injection schemes produced significantly different flow features, the CARS method provided mean temperature, N2, O2 and H2 maps at multiple downstream locations for both. The primary aim of these measurements was to provide detailed flowfield information for computational fluid dynamics (CFD) code validation.

Study on the Effect of water Injection Momentum on the Cooling Effect of Rocket Engine Exhaust Plume

NASA Astrophysics Data System (ADS)

Yang, Kan; Qiang, Yanhui; Zhong, Chenghang; Yu, Shaozhen

2017-10-01

For the study of water injection momentum factors impact on flow field of the rocket engine tail flame, the numerical computation model of gas-liquid two phase flow in the coupling of high temperature and high speed gas flow and low temperature liquid water is established. The accuracy and reliability of the numerical model are verified by experiments. Based on the numerical model, the relationship between the flow rate and the cooling effect is analyzed by changing the water injection momentum of the water spray pipes. And the effective mathematical expression is obtained. What’s more, by changing the number of the water spray and using small flow water injection, the cooling effect is analyzed to check the application range of the mathematical expressions. The results show that: the impact and erosion of the gas flow field could be reduced greatly by water injection, and there are two parts in the gas flow field, which are the slow cooling area and the fast cooling area. In the fast cooling area, the influence of the water flow momentum and nozzle quantity on the cooling effect can be expressed by mathematical functions without causing bifurcation flow for the mainstream gas. The conclusion provides a theoretical reference for the engineering application.

System and Method for Traversing Pipes

NASA Technical Reports Server (NTRS)

Graf, Jodi (Inventor); Pettinger, Ross (Inventor); Azimi, Shaun (Inventor); Magruder, Darby (Inventor); Ridley, Justin (Inventor); Lapp, Anthony (Inventor)

2017-01-01

A system and method is provided for traversing inside one or more pipes. In an embodiment, a fluid is injected into the one or more pipes thereby promoting a fluid flow. An inspection device is deployed into the one or more pipes at least partially filled with a flowing fluid. The inspection device comprises a housing wherein the housing is designed to exploit the hydrokinetic effects associated with a fluid flow in one or more pipes as well as maneuver past a variety of pipe configurations. The inspection device may contain one or more sensors capable of performing a variety of inspection tasks.

Material flow data for numerical simulation of powder injection molding

NASA Astrophysics Data System (ADS)

Duretek, I.; Holzer, C.

2017-01-01

The powder injection molding (PIM) process is a cost efficient and important net-shape manufacturing process that is not completely understood. For the application of simulation programs for the powder injection molding process, apart from suitable physical models, exact material data and in particular knowledge of the flow behavior are essential in order to get precise numerical results. The flow processes of highly filled polymers are complex. Occurring effects are very hard to separate, like shear flow with yield stress, wall slip, elastic effects, etc. Furthermore, the occurrence of phase separation due to the multi-phase composition of compounds is quite probable. In this work, the flow behavior of a 316L stainless steel feedstock for powder injection molding was investigated. Additionally, the influence of pre-shearing on the flow behavior of PIM-feedstocks under practical conditions was examined and evaluated by a special PIM injection molding machine rheometer. In order to have a better understanding of key factors of PIM during the injection step, 3D non-isothermal numerical simulations were conducted with a commercial injection molding simulation software using experimental feedstock properties. The simulation results were compared with the experimental results. The mold filling studies amply illustrate the effect of mold temperature on the filling behavior during the mold filling stage. Moreover, the rheological measurements showed that at low shear rates no zero shear viscosity was observed, but instead the viscosity further increased strongly. This flow behavior could be described with the Cross-WLF approach with Herschel-Bulkley extension very well.

Injectant mole-fraction imaging in compressible mixing flows using planar laser-induced iodine fluorescence

NASA Technical Reports Server (NTRS)

Hartfield, Roy J., Jr.; Abbitt, John D., III; Mcdaniel, James C.

1989-01-01

A technique is described for imaging the injectant mole-fraction distribution in nonreacting compressible mixing flow fields. Planar fluorescence from iodine, seeded into air, is induced by a broadband argon-ion laser and collected using an intensified charge-injection-device array camera. The technique eliminates the thermodynamic dependence of the iodine fluorescence in the compressible flow field by taking the ratio of two images collected with identical thermodynamic flow conditions but different iodine seeding conditions.

PTV analysis of the entrained air into the diesel spray at high-pressure injection

NASA Astrophysics Data System (ADS)

Toda, Naoki; Yamashita, Hayato; Mashida, Makoto

2014-08-01

In order to clarify the effect of high-pressure injection on soot reduction in terms of the air entrainment into spray, the air flow surrounding the spray and set-off length indicating the distance from the nozzle tip to the flame region in diffusion diesel combustion were investigated using 300MPa injection of a multi-hole injector. The measurement of the air entrainment flow was carried out at non-evaporating condition using consecutive PTV (particle tracking velocimetry) method with a high-speed camera and a high-frequency pulse YAG laser. The set-off length was measured at highpressure and high-temperature using the combustion bomb of constant volume and optical system of shadow graph method. And the amount of air entrainment into spray until reaching set-off length in diffusion combustion was studied as a factor of soot formation.

Local heat transfer in turbine disk-cavities. I - Rotor and stator cooling with hub injection of coolant

NASA Astrophysics Data System (ADS)

Bunker, R. S.; Metzger, D. E.; Wittig, S.

1990-06-01

Detailed radial heat-transfer coefficient distributions applicable to the cooling of disk-cavity regions of gas turbines are obtained experimentally from local heat-transfer data on both the rotating and stationary surfaces of a parallel-geometry disk-cavity system. Attention is focused on the hub injection of a coolant over a wide range of parameters including disk rotational Reynolds numbers of 200,000 to 50,000, rotor/stator spacing-to-disk ratios of 0.025 to 0.15, and jet mass flow rates between 0.10 and 0.40 times the turbulent pumped flow rate of a free disk. It is shown that rotor heat transfer exhibits regions of impingement and rotational domination with a transition region between, while stator heat transfer displays flow reattachment and convection regions with an inner recirculation zone.

Axisymmetric flows from fluid injection into a confined porous medium

NASA Astrophysics Data System (ADS)

Guo, Bo; Zheng, Zhong; Celia, Michael A.; Stone, Howard A.

2016-02-01

We study the axisymmetric flows generated from fluid injection into a horizontal confined porous medium that is originally saturated with another fluid of different density and viscosity. Neglecting the effects of surface tension and fluid mixing, we use the lubrication approximation to obtain a nonlinear advection-diffusion equation that describes the time evolution of the sharp fluid-fluid interface. The flow behaviors are controlled by two dimensionless groups: M, the viscosity ratio of displaced fluid relative to injected fluid, and Γ, which measures the relative importance of buoyancy and fluid injection. For this axisymmetric geometry, the similarity solution involving R2/T (where R is the dimensionless radial coordinate and T is the dimensionless time) is an exact solution to the nonlinear governing equation for all times. Four analytical expressions are identified as asymptotic approximations (two of which are new solutions): (i) injection-driven flow with the injected fluid being more viscous than the displaced fluid (Γ ≪ 1 and M < 1) where we identify a self-similar solution that indicates a parabolic interface shape; (ii) injection-driven flow with injected and displaced fluids of equal viscosity (Γ ≪ 1 and M = 1), where we find a self-similar solution that predicts a distinct parabolic interface shape; (iii) injection-driven flow with a less viscous injected fluid (Γ ≪ 1 and M > 1) for which there is a rarefaction wave solution, assuming that the Saffman-Taylor instability does not occur at the reservoir scale; and (iv) buoyancy-driven flow (Γ ≫ 1) for which there is a well-known self-similar solution corresponding to gravity currents in an unconfined porous medium [S. Lyle et al. "Axisymmetric gravity currents in a porous medium," J. Fluid Mech. 543, 293-302 (2005)]. The various axisymmetric flows are summarized in a Γ-M regime diagram with five distinct dynamic behaviors including the four asymptotic regimes and an intermediate regime. The implications of the regime diagram are discussed using practical engineering projects of geological CO2 sequestration, enhanced oil recovery, and underground waste disposal.

Research and development of a luminol-carbon monoxide flow system

NASA Technical Reports Server (NTRS)

Thomas, R. R.

1977-01-01

Adaption of the luminol-carbon monoxide injection system to a flowing type system is reported. Analysis of actual wastewater samples was carried out and revealed that bacteria can be associated with particles greater than 10 microns in size in samples such as mixed liquor. Research into the luminol reactive oxidation state indicates that oxidized iron porphyrins, cytochrome-c in particular, produce more luminol chemiluminescence than the reduced form. Correlation exists between the extent of porphyrin oxidation and relative chemiluminescence. In addition, the porphyrin nucleus is apparently destroyed under the current chemiluminescent reaction conditions.

Fluid Flow Prediction with Development System Interwell Connectivity Influence

NASA Astrophysics Data System (ADS)

Bolshakov, M.; Deeva, T.; Pustovskikh, A.

2016-03-01

In this paper interwell connectivity has been studied. First of all, literature review of existing methods was made which is divided into three groups: Statistically-Based Methods, Material (fluid) Propagation-Based Methods and Potential (pressure) Change Propagation-Based Method. The disadvantages of the first and second groups are as follows: methods do not involve fluid flow through porous media, ignore any changes of well conditions (BHP, skin factor, etc.). The last group considers changes of well conditions and fluid flow through porous media. In this work Capacitance method (CM) has been chosen for research. This method is based on material balance and uses weight coefficients lambdas to assess well influence. In the next step synthetic model was created for examining CM. This model consists of an injection well and a production well. CM gave good results, it means that flow rates which were calculated by analytical method (CM) show matching with flow rate in model. Further new synthetic model was created which includes six production and one injection wells. This model represents seven-spot pattern. To obtain lambdas weight coefficients, the delta function was entered using by minimization algorithm. Also synthetic model which has three injectors and thirteen producer wells was created. This model simulates seven-spot pattern production system. Finally Capacitance method (CM) has been adjusted on real data of oil Field Ω. In this case CM does not give enough satisfying results in terms of field data liquid rate. In conclusion, recommendations to simplify CM calculations were given. Field Ω is assumed to have one injection and one production wells. In this case, satisfying results for production rates and cumulative production were obtained.

Analysis of Tests of Subsurface Injection, Storage, and Recovery of Freshwater in Lancaster, Antelope Valley, California

USGS Publications Warehouse

Phillips, Steven P.; Carlson, Carl S.; Metzger, Loren F.; Howle, James F.; Galloway, Devin L.; Sneed, Michelle; Ikehara, Marti E.; Hudnut, Kenneth W.; King, Nancy E.

2003-01-01

Ground-water levels in Lancaster, California, declined more than 200 feet during the 20th century, resulting in reduced ground-water supplies and more than 6 feet of land subsidence. Facing continuing population growth, water managers are seeking solutions to these problems. Injection of imported, treated fresh water into the aquifer system when it is most available and least expensive, for later use during high-demand periods, is being evaluated as part of a management solution. The U.S. Geological Survey, in cooperation with the Los Angeles County Department of Public Works and the Antelope Valley-East Kern Water Agency, monitored a pilot injection program, analyzed the hydraulic and subsidence-related effects of injection, and developed a simulation/optimization model to help evaluate the effectiveness of using existing and proposed wells in an injection program for halting the decline of ground-water levels and avoiding future land subsidence while meeting increasing ground-water demand. A variety of methods were used to measure aquifer-system response to injection. Water levels were measured continuously in nested (multi-depth) piezometers and monitoring wells and periodically in other wells that were within several miles of the injection site. Microgravity surveys were done to estimate changes in the elevation of the water table in the absence of wells and to estimate specific yield. Aquifer-system deformation was measured directly and continuously using a dual borehole extensometer and indirectly using continuous Global Positioning System (GPS), first-order spirit leveling, and an array of tiltmeters. The injected water and extracted water were sampled periodically and analyzed for constituents, including chloride and trihalomethanes. Measured injection rates of about 750 gallons per minute (gal/min) per well at the injection site during a 5-month period showed that injection at or above the average extraction rates at that site (about 800 gal/min) was hydraulically feasible. Analyses of these data took many forms. Coupled measurements of gravity and water-level change were used to estimate the specific yield near the injection wells, which, in turn, was used to estimate areal water-table changes from distributed measurements of gravity change. Values of the skeletal components of aquifer-system storage, which are key subsidence-related characteristics of the system, were derived from continuous measurements of water levels and aquifer-system deformation. A numerical model of ground-water flow was developed for the area surrounding Lancaster and used to estimate horizontal and vertical hydraulic conductivities. A chemical mass balance was done to estimate the recovery of injected water. The ground-water-flow model was used to project changes in ground-water levels for 10 years into the future, assuming no injection, no change in pumping distribution, and forecasted increases in ground-water demand. Simulated ground-water levels decreased throughout the Lancaster area, suggesting that land subsidence would continue as would the depletion of ground-water supplies and an associated loss of well production capacity. A simulation/optimization model was developed to help identify optimal injection and extraction rates for 16 existing and 13 proposed wells to avoid future land subsidence and to minimize loss of well production capacity while meeting increasing ground-water demands. Results of model simulations suggest that these objectives can be met with phased installation of the proposed wells during the 10-year period. Water quality was not considered in the optimization, but chemical-mass-balance results indicate that a sustained injection program likely would have residual effects on the chemistry of ground water.

Droplet Diameter and Size Distribution of JP-4 Fuel Injected into a Subsonic Airstream

DTIC Science & Technology

1975-04-01

Pressure TF1 /2 Fuel Temperatures WFL1/2 Low-Range Flow Rate WFM1/2 Mid-Range Flow Rate WFH1/2 High-Range Flow Rate Metering Orifices Manual...Millivolt Tables Plenum Tempera- ture, TP1, •F — ±0.27"F 100 — + 1.8*F ±2.3"F -10 to 70* F Data Acquisition System f f Fuel Supply TF1 — TF2

Numerical analysis of combustion characteristics of hybrid rocket motor with multi-section swirl injection

NASA Astrophysics Data System (ADS)

Li, Chengen; Cai, Guobiao; Tian, Hui

2016-06-01

This paper is aimed to analyse the combustion characteristics of hybrid rocket motor with multi-section swirl injection by simulating the combustion flow field. Numerical combustion flow field and combustion performance parameters are obtained through three-dimensional numerical simulations based on a steady numerical model proposed in this paper. The hybrid rocket motor adopts 98% hydrogen peroxide and polyethylene as the propellants. Multiple injection sections are set along the axis of the solid fuel grain, and the oxidizer enters the combustion chamber by means of tangential injection via the injector ports in the injection sections. Simulation results indicate that the combustion flow field structure of the hybrid rocket motor could be improved by multi-section swirl injection method. The transformation of the combustion flow field can greatly increase the fuel regression rate and the combustion efficiency. The average fuel regression rate of the motor with multi-section swirl injection is improved by 8.37 times compared with that of the motor with conventional head-end irrotational injection. The combustion efficiency is increased to 95.73%. Besides, the simulation results also indicate that (1) the additional injection sections can increase the fuel regression rate and the combustion efficiency; (2) the upstream offset of the injection sections reduces the combustion efficiency; and (3) the fuel regression rate and the combustion efficiency decrease with the reduction of the number of injector ports in each injection section.

Multi-modal in vivo imaging of brain blood oxygenation, blood flow and neural calcium dynamics during acute seizures

NASA Astrophysics Data System (ADS)

Ringuette, Dene; Jeffrey, Melanie A.; Carlen, Peter L.; Levi, Ofer

2016-03-01

Dysfunction of the vascular endothelium has been implicated in the development of epilepsy. To better understand the relation between vascular function and seizure and provide a foundation for interpreting results from functional imaging in chronic disease models, we investigate the relationship between intracellular calcium dynamics and local cerebral blood flow and blood oxygen saturation during acute seizure-like events and pharmacological seizure rescue. To probe the relation between the aforementioned physiological markers in an acute model of epilepsy in rats, we integrated three different optical modalities together with electrophysiological recordings: Laser speckle contrast imaging (LSCI) was used to study changes in flow speeds, Intrinsic optical signal imaging (IOSI) was used to monitor changes in oxygenated, de-oxygenated, and total hemoglobin concentration, and Calcium-sensitive dye imaging was used to monitor intracellular calcium dynamics. We designed a dedicated cortical flow chamber to remove superficial blood and dye resulting from the injection procedure, which reduced spurious artifacts. The near infrared light used for IOSI and LSCI was delivered via a light pipe integrated with the flow chamber to minimize the effect of fluid surface movement on illumination stability. Calcium-sensitive dye was injected via a glass electrode used for recording the local field potential. Our system allowed us to observe and correlate increases in intracellular calcium, blood flow and blood volume during seizure-like events and provide a quantitative analysis of neurovascular coupling changes associated with seizure rescue via injection of an anti-convulsive agent.

Flow friction of the turbulent coolant flow in cryogenic porous cables

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Yeroshenko, V. M.; Zaichik, L. I.; Yanovsky, L. S.

1979-01-01

Considered are cryogenic power transmission cables with porous cores. Calculations of the turbulent coolant flow with injection or suction through the porous wall are presented within the framework of a two-layer model. Universal velocity profiles were obtained for the viscous sublayer and flow core. Integrating the velocity profile, the law of flow friction in the pipe with injection has been derived for the case when there is a tangential injection velocity component. The effect of tangential velocity on the relative law of flow friction is analyzed. The applicability of the Prandtl model to the problem under study is discussed. It is shown that the error due to the acceptance of the model increases with the injection parameter and at lower Reynolds numbers; under these circumstances, the influence of convective terms in the turbulent energy equation on the mechanism of turbulent transport should be taken into account.

Delineating Area of Review in a System with Pre-injection Relative Overpressure

DOE PAGES

Oldenburg, Curtis M.; Cihan, Abdullah; Zhou, Quanlin; ...

2014-12-31

The Class VI permit application for geologic carbon sequestration (GCS) requires delineation of an area of review (AoR), defined as the region surrounding the (GCS) project where underground sources of drinking water (USDWs) may be endangered. The methods for estimating AoR under the Class VI regulation were developed assuming that GCS reservoirs would be in hydrostatic equilibrium with overlying aquifers. Here we develop and apply an approach to estimating AoR for sites with preinjection relative overpressure for which standard AoR estimation methods produces an infinite AoR. The approach we take is to compare brine leakage through a hypothetical open flowmore » path in the base-case scenario (no-injection) to the incrementally larger leakage that would occur in the CO 2-injection case. To estimate AoR by this method, we used semi-analytical solutions to single-phase flow equations to model reservoir pressurization and flow up (single) leaky wells located at progressively greater distances from the injection well. We found that the incrementally larger flow rates for hypothetical leaky wells located 6 km and 4 km from the injection well are ~20% and 30% greater, respectively, than hypothetical baseline leakage rates. If total brine leakage is considered, the results depend strongly on how the incremental increase in total leakage is calculated, varying from a few percent to up to 40% greater (at most at early time) than base-case total leakage.« less

Bienzymatic Biosensor for Rapid Detection of Aspartame by Flow Injection Analysis

PubMed Central

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

2014-01-01

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. PMID:24412899

Bienzymatic biosensor for rapid detection of aspartame by flow injection analysis.

PubMed

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.

Distribution of injected power fluctuations in electroconvection.

PubMed

Tóth-Katona, Tibor; Gleeson, J T

2003-12-31

We report on the distribution spectra of the fluctations in the amount of power injected into a liquid crystal undergoing electroconvective flow. The probability distribution functions (PDFs) of the fluc-tuations as well as the magnitude of the fluctuations have been determined in a wide range of imposed stress both for unconfined and confined flow geometries. These spectra are compared to those found in other systems held far from equilibrium, and find that in certain conditions we obtain the universal PDF form reported by Phys. Rev. Lett. 84, 3744 (2000)]. Moreover, the PDF approaches this universal form via an interesting mechanism whereby the distribution's negative tail evolves towards form in a different manner than the positive tail.

Purged window apparatus. [On-line spectroscopic analysis of gas flow systems

DOEpatents

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.

A dimensionless parameter approach to the thermal behavior of an aquifer thermal energy storage system

NASA Astrophysics Data System (ADS)

Doughty, C.; Hellstrom, G.; Tsang, C. F.; Claesson, J.

1982-09-01

The purpose of aquifer thermal energy storage (ATES) site-characterization studies is to develop a general procedure whereby the energy recovery factor for a given site may be predicted readily for a wide range of operating conditions without doing detailed numerical simulations. The thermal behavior of a ATES system with steady radial fluid flow around a single injection/production well is discussed. Buoyancy flow is neglected, and the aquifer is confined above and below by impermeable confining layers.

Proppant backflow: Mechanical and flow considerations

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLennan, John; Walton, Ian; Moore, Joseph

2015-09-01

One of the concerns of using proppant in geothermal wells, and particularly in enhanced geothermal systems, is proppant flowback. Particulate proppant maintain post-closure conductivity in hydraulically opened fractures. If that proppant is displaced from the near-wellbore region, either due to overflushing during stimulation or flowback to the wellbore at any time, the reduced fracture width chokes the injection or production. Two intermediate-scale laboratory analogs of a propped hydraulic fracture were prepared, and fluid was flowed through a normally stressed, propped fracture into a central wellbore. The tests were conducted in a polyaxial load frame. Acoustic/microseismic activity was measured during themore » injection programs. In one scenario—radial flow through a transverse fracture to a wellbore—the results suggest the creation of flow channels and nominally intact propped zones around the channels, maintaining fracture aperture. In the other—linear flow through a longitudinal fracture into a wellbore—there was substantially more proppant removal. The measurements have shown a greater tendency for proppant flowback in a linear flow situation (proppant movement is kinematically more restricted for radial convergent flow). The pressure gradients causing flow are exceedingly small and restraining flowback will be difficult. Convergent flow relationships could be an issue for injector wells, which will experience fluid flowback during hard shutdowns.« less

Effect of injection velocity and particle concentration on transport of nanoscale zero-valent iron and hydraulic conductivity in saturated porous media

NASA Astrophysics Data System (ADS)

Strutz, Tessa J.; Hornbruch, Götz; Dahmke, Andreas; Köber, Ralf

2016-08-01

Successful groundwater remediation by injecting nanoscale zero-valent iron (NZVI) particles requires efficient particle transportation and distribution in the subsurface. This study focused on the influence of injection velocity and particle concentration on the spatial NZVI particle distribution, the deposition processes and on quantifying the induced decrease in hydraulic conductivity (K) as a result of particle retention by lab tests and numerical simulations. Horizontal column tests of 2 m length were performed with initial Darcy injection velocities (q0) of 0.5, 1.5, and 4.1 m/h and elemental iron input concentrations (Fe0in) of 0.6, 10, and 17 g/L. Concentrations of Fe0 in the sand were determined by magnetic susceptibility scans, which provide detailed Fe0 distribution profiles along the column. NZVI particles were transported farther at higher injection velocity and higher input concentrations. K decreased by one order of magnitude during injection in all experiments, with a stronger decrease after reaching Fe0 concentrations of about 14-18 g/kg(sand). To simulate the observed nanoparticle transport behavior the existing finite-element code OGS has been successfully extended and parameterized for the investigated experiments using blocking, ripening, and straining as governing deposition processes. Considering parameter relationships deduced from single simulations for each experiment (e.g. deposition rate constants as a function of flow velocity) one mean parameter set has been generated reproducing the observations in an adequate way for most cases of the investigated realistic injection conditions. An assessment of the deposition processes related to clogging effects showed that the percentage of retention due to straining and ripening increased during experimental run time resulting in an ongoing reduction of K. Clogging is mainly evoked by straining which dominates particle deposition at higher flow velocities, while blocking and ripening play a significant role for attachment, mainly at lower injection velocities. Since the injection of fluids at real sites leads to descending flow velocities with increasing radial distance from the injection point, the simulation of particle transport requires accounting for all deposition processes mentioned above. Thus, the derived mean parameter set can be used as a basis for quantitative and predictive simulations of particle distributions and clogging effects at both lab and field scale. Since decreases in K can change the flow system, which may have positive as well as negative implications for the in situ remediation technology at a contaminated site, a reliable simulation is thus of great importance for NZVI injection and prediction.

Containment of subsurface contaminants

DOEpatents

Corey, John C.

1994-01-01

A barrier for reducing the spread of a plume of subsurface contaminants. The apparatus includes a well system for injecting a fluid, such as air, just outside and below the periphery of the plume. The fluid is injected at a pressure sufficient to lower the hydraulic conductivity of the soil from the point of injection to the surface thus establishing a curtain-like barrier to groundwater movement. The barrier is established upgradient of the plume to divert groundwater away, or preferably completely around the plume to reduce the flow of groundwater into or out of the plume. The barrier enables the remediation of the confined contamination and then, when the injection of the fluid is halted, the barrier quickly dissipates.

CFD Analyses and Jet-Noise Predictions of Chevron Nozzles with Vortex Stabilization

NASA Technical Reports Server (NTRS)

Dippold, Vance

2008-01-01

The wind computational fluid dynamics code was used to perform a series of analyses on a single-flow plug nozzle with chevrons. Air was injected from tubes tangent to the nozzle outer surface at three different points along the chevron at the nozzle exit: near the chevron notch, at the chevron mid-point, and near the chevron tip. Three injection pressures were used for each injection tube location--10, 30, and 50 psig-giving injection mass flow rates of 0.1, 0.2, and 0.3 percent of the nozzle mass flow. The results showed subtle changes in the jet plume s turbulence and vorticity structure in the region immediately downstream of the nozzle exit. Distinctive patterns in the plume structure emerged from each injection location, and these became more pronounced as the injection pressure was increased. However, no significant changes in centerline velocity decay or turbulent kinetic energy were observed in the jet plume as a result of flow injection. Furthermore, computational acoustics calculations performed with the JeNo code showed no real reduction in jet noise relative to the baseline chevron nozzle.

Determination of nitrite and nitrate in water samples by an automated hydrodynamic sequential injection method.

PubMed

Somnam, Sarawut; Jakmunee, Jaroon; Grudpan, Kate; Lenghor, Narong; Motomizu, Shoji

2008-12-01

An automated hydrodynamic sequential injection (HSI) system with spectrophotometric detection was developed. Thanks to the hydrodynamic injection principle, simple devices can be used for introducing reproducible microliter volumes of both sample and reagent into the flow channel to form stacked zones in a similar fashion to those in a sequential injection system. The zones were then pushed to the detector and a peak profile was recorded. The determination of nitrite and nitrate in water samples by employing the Griess reaction was chosen as a model. Calibration graphs with linearity in the range of 0.7 - 40 muM were obtained for both nitrite and nitrate. Detection limits were found to be 0.3 muM NO(2)(-) and 0.4 muM NO(3)(-), respectively, with a sample throughput of 20 h(-1) for consecutive determination of both the species. The developed system was successfully applied to the analysis of water samples, employing simple and cost-effective instrumentation and offering higher degrees of automation and low chemical consumption.

Dual-Valve and Counter-Flow Surface Plasmon Resonance.

PubMed

Wang, Xiaoying; Zhou, Feimeng

2018-04-17

Two six-port injector valves and one selector valve commonly used in flow injection analysis are combined with a surface plasmon resonance (SPR) instrument wherein solutions introduced from the two inlets counter-flow inside the flow cell. The system is versatile as the same or different solutions can be rapidly and repeatedly introduced to the two fluidic channels in series or in parallel. Unlike most commercial SPR instruments employing a single injector valve, solutions separately injected from the two injector valves can be readily exchanged (<1 s) between the two channels. This new method, referred to as the alternate injection mode, not only saves analysis time but also facilitates efficient and facile surface reactions for ligand immobilization and prevents immobilized species from desorbing. These advantages are demonstrated with the measurements of binding of acetazolamide (222.2 Da) to histidine-tagged human carbonic anhydrase II (his-tagged HCA). Amine-containing residues of his-tagged HCA molecules tethered at Ni-nitrilotriacetic acid (NTA) sensors were rapidly cross-linked to the underlying carboxymethylated dextran. The higher ligand densities and more stable surfaces are essential for SPR detection of small molecule binding. In a different application, microglobulin solutions of increasing concentrations were introduced for continuous binding to the preimmobilized antibody. The kinetic and affinity measurements can be conducted without performing repeated dissociation and surface regeneration reactions.

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

NASA Technical Reports Server (NTRS)

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.

Sequential Injection/Electrochemical Immunoassay for Quantifying the Pesticide Metabolite 3, 5, 6-Trichloro-2-Pyridinol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guodong; Riechers, Shawn L.; Timchalk, Chuck

2005-12-04

An automated and sensitive sequential injection electrochemical immunoassay was developed to monitor a potential insecticide biomarker, 3, 5, 6-trichloro-2-pyridinol. The current method involved a sequential injection analysis (SIA) system equipped with a thin-layer electrochemical flow cell and permanent magnet, which was used to fix 3,5,6-trichloro-2-pyridinol (TCP) antibody coated magnetic beads (TCP-Ab-MBs) in the reaction zone. After competitive immunoreactions among TCP-Ab-MBs, TCP analyte, and horseradish peroxidase (HRP) labeled TCP, a 3, 3?, 5, 5?-tetramethylbenzidine dihydrochloride and hydrogen peroxide (TMB-H2O2) substrate solution was injected to produce an electroactive enzymatic product. The activity of HRP tracers was monitored by a square wave voltammetricmore » scanning electroactive enzymatic product in the thin-layer flow cell. The voltammetric characteristics of the substrate and the enzymatic product were investigated under batch conditions, and the parameters of the immunoassay were optimized in the SIA system. Under the optimal conditions, the system was used to measure as low as 6 ng L-1 (ppt) TCP, which is around 50-fold lower than the value indicated by the manufacturer of the TCP RaPID Assay? kit (0.25 ug/L, colorimetric detection). The performance of the developed immunoassay system was successfully evaluated on tap water and river water samples spiked with TCP. This technique could be readily used for detecting other environmental contaminants by developing specific antibodies against contaminants and is expected to open new opportunities for environmental and biological monitoring.« less

Experimental Investigation of Centrifugal Compressor Stabilization Techniques

NASA Technical Reports Server (NTRS)

Skoch, Gary J.

2003-01-01

Results from a series of experiments to investigate techniques for extending the stable flow range of a centrifugal compressor are reported. The research was conducted in a high-speed centrifugal compressor at the NASA Glenn Research Center. The stabilizing effect of steadily flowing air-streams injected into the vaneless region of a vane-island diffuser through the shroud surface is described. Parametric variations of injection angle, injection flow rate, number of injectors, injector spacing, and injection versus bleed were investigated for a range of impeller speeds and tip clearances. Both the compressor discharge and an external source were used for the injection air supply. The stabilizing effect of flow obstructions created by tubes that were inserted into the diffuser vaneless space through the shroud was also investigated. Tube immersion into the vaneless space was varied in the flow obstruction experiments. Results from testing done at impeller design speed and tip clearance are presented. Surge margin improved by 1.7 points using injection air that was supplied from within the compressor. Externally supplied injection air was used to return the compressor to stable operation after being throttled into surge. The tubes, which were capped to prevent mass flux, provided 9.3 points of additional surge margin over the baseline surge margin of 11.7 points.

Transient foam flow in porous media with CAT Scanner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Dianbin; Brigham, W.E.

1992-03-01

Transient behavior is likely to dominate over most of the duration of a foam injection field project. Due to the lack of date, little is presently known about transient foam flow behavior. Foam flow does not follow established models such as the Buckley-Leverett theory, and no general predictive model has been derived. Therefore, both experimental data and a foam flow theory are needed. In this work, foam was injected at a constant mass rate into one-dimensional sandpacks of 1-in diameter and 24-in or 48-in length that had initially been saturate with distilled water. The system was placed in a catmore » Scanner. Data, obtained at room temperature and low pressure at various times, include both the pressure and saturation distributions. Pressure profiles showed that the pressure gradient is much greater behind the foam front than ahead of it. Moreover, the pressure gradients keep changing as the foam advances in the sandpack. This behavior differs from Buckley-Leverett theory. The CT scan results demonstrated gas channeling near the front, but eventually the foam block all these channels and sweeps the entire cross section after many pore volumes of injection. Three series of experiments were run: (1) surfactant adsorption measurements; (2) gas displacements of surfactant-laden solutions and (3) foam displacements. The first two series of experiments were made to provide the necessary parameters required to match the foam displacements. To this end, it was necessary to smooth the saturation history data, using a Langmuir-type formula. A theory was proposed based on the principles of the fractional flow curve construction method. This foam theory treats the foam as composed of infinitesimal slugs of gas of varying viscosities. The foam front has the lowest viscosity and foam at the injection end has the highest.« less

Renal and femoral venous blood flows are regulated by different mechanisms dependent on α-adrenergic receptor subtypes and nitric oxide in anesthetized rats.

PubMed

Fioretti, Alexandre C; Ogihara, Cristiana A; Cafarchio, Eduardo M; Venancio, Daniel P; de Almeida, Roberto Lopes; Antonio, Bruno B; Sato, Monica A

2017-12-01

Venous and arterial walls are responsive to sympathetic system and circulating substances, nevertheless, very few is known about the venous blood flow regulation simultaneously to arterial vascular beds. In this study, we compared the venous and arterial blood flow regulation in visceral and muscular beds upon injection of different doses of vasoactive drugs which act in arterial vascular beds. Anesthetized adult male Wistar rats underwent to right femoral artery and vein cannulation for hemodynamic recordings and infusion of drugs. Doppler flow probes were placed around the left renal artery and vein, and left femoral artery and vein to evaluate the changes in flood flow. Phenylephrine (PHE) injection (α 1 -adrenergic receptor agonist) elicited vasoconstriction in all arteries and veins. Intravenous prazosin (PZS) (1mg/kg, α 1 -adrenergic receptor blocker) caused renal artery vasodilation, but not in the other beds. Vasoconstrictor effect of PHE was abolished by PZS in all vascular beds, except in femoral vein. Phentolamine (PTL) injection (1mg/kg, α 1 /α 2 -adrenergic receptor blocker) produced renal artery vasodilation with no change in other beds. After PTL, the vasoconstriction evoked by PHE was abolished in all vascular beds. Sodium Nitroprusside (SNP), a nitric oxide donor, elicited vasodilation in all beds, and after PTL but not post PZS injection, SNP enhanced the vasodilatory effect in femoral vein. Our findings suggest that the vasoconstriction in renal and femoral veins is mediated by different subtypes of α-adrenoceptors. The nitric oxide-dependent vasodilation in femoral vein enhances when α 2 -adrenoceptors are not under stimulation, but not in the other vascular beds investigated. Copyright © 2017 Elsevier Inc. All rights reserved.

3D-printed and CNC milled flow-cells for chemiluminescence detection.

PubMed

Spilstead, Kara B; Learey, Jessica J; Doeven, Egan H; Barbante, Gregory J; Mohr, Stephan; Barnett, Neil W; Terry, Jessica M; Hall, Robynne M; Francis, Paul S

2014-08-01

Herein we explore modern fabrication techniques for the development of chemiluminescence detection flow-cells with features not attainable using the traditional coiled tubing approach. This includes the first 3D-printed chemiluminescence flow-cells, and a milled flow-cell designed to split the analyte stream into two separate detection zones within the same polymer chip. The flow-cells are compared to conventional detection systems using flow injection analysis (FIA) and high performance liquid chromatography (HPLC), with the fast chemiluminescence reactions of an acidic potassium permanganate reagent with morphine and a series of adrenergic phenolic amines. Copyright © 2014 Elsevier B.V. All rights reserved.

Fuel injection assembly for gas turbine engine combustor

NASA Technical Reports Server (NTRS)

Candy, Anthony J. (Inventor); Glynn, Christopher C. (Inventor); Barrett, John E. (Inventor)

2002-01-01

A fuel injection assembly for a gas turbine engine combustor, including at least one fuel stem, a plurality of concentrically disposed tubes positioned within each fuel stem, wherein a cooling supply flow passage, a cooling return flow passage, and a tip fuel flow passage are defined thereby, and at least one fuel tip assembly connected to each fuel stem so as to be in flow communication with the flow passages, wherein an active cooling circuit for each fuel stem and fuel tip assembly is maintained by providing all active fuel through the cooling supply flow passage and the cooling return flow passage during each stage of combustor operation. The fuel flowing through the active cooling circuit is then collected so that a predetermined portion thereof is provided to the tip fuel flow passage for injection by the fuel tip assembly.

Gas-injection-start and shutdown characteristics of a 2-kilowatt to 15-kilowatt Brayton power system

NASA Technical Reports Server (NTRS)

Cantoni, D. A.

1972-01-01

Two methods of starting the Brayton power system have been considered: (1) using the alternator as a motor to spin the Brayton rotating unit (BRU), and (2) spinning the BRU by forced gas injection. The first method requires the use of an auxiliary electrical power source. An alternating voltage is applied to the terminals of the alternator to drive it as an induction motor. Only gas-injection starts are discussed in this report. The gas-injection starting method requires high-pressure gas storage and valves to route the gas flow to provide correct BRU rotation. An analog computer simulation was used to size hardware and to determine safe start and shutdown procedures. The simulation was also used to define the range of conditions for successful startups. Experimental data were also obtained under various test conditions. These data verify the validity of the start and shutdown procedures.

Glacial uplift: fluid injection beneath an elastic sheet on a poroelastic substrate

NASA Astrophysics Data System (ADS)

Neufeld, Jerome; Hewitt, Duncan; Chini, Greg

2016-11-01

Supraglacial lakes can drain to the base of glaciers extremely rapidly, causing localised uplift of the surrounding glacier and affecting its sliding velocity. The means by which large volumes of drained water interact with and leak into the subglacial hydrological system is unclear, as is the role of the basal till. A theoretical study of the spread of fluid injected below an elastic sheet (the ice) is presented, where the ice lies above, and initially compresses, a deformable poroelastic layer. As pressurized fluid is injected, the deformable layer swells to accommodate more fluid. If sufficient fluid is injected, a 'blister' of fluid forms above the layer, causing the overburden to lift off the base. The flow is controlled by the local pressure drop across the tip of this blister, which depends subtly on both the flow of fluid through the porous layer below the tip, and on poroelastic deformation in the till ahead of the tip. The spreading behaviour and dependence on key parameters is analysed. Predictions of the model are compared to field measurements of uplift from draining glacial lakes in Greenland.

Preparation of Fe(3)O(4)@C@CNC multifunctional magnetic core/shell nanoparticles and their application in a signal-type flow-injection photoluminescence immunosensor.

PubMed

Chu, Chengchao; Li, Meng; Li, Long; Ge, Shenguang; Ge, Lei; Yu, Jinghua; Yan, Mei; Song, Xianrang

2013-11-01

We describe here the preparation of carbon-coated Fe3O4 magnetic nanoparticles that were further fabricated into multifunctional core/shell nanoparticles (Fe3O4@C@CNCs) through a layer-by-layer self-assembly process of carbon nanocrystals (CNCs). The nanoparticles were applied in a photoluminescence (PL) immunosensor to detect the carcinoembryonic antigen (CEA), and CEA primary antibody was immobilized onto the surface of the nanoparticles. In addition, CEA secondary antibody and glucose oxidase were covalently bonded to silica nanoparticles. After stepwise immunoreactions, the immunoreagent was injected into the PL cell using a flow-injection PL system. When glucose was injected, hydrogen peroxide was obtained because of glucose oxidase catalysis and quenched the PL of the Fe3O4@C@CNC nanoparticles. The here proposed PL immunosensor allowed us to determine CEA concentrations in the 0.005–50 ng·mL-1 concentration range, with a detection limit of 1.8 pg·mL-1.

[Comparison and Discussion of National/Military Standards Related to Flow Measurement of Medical Injection Pump].

PubMed

Zhang, Nan; Zhou, Juan; Yu, Jinlai; Hua, Ziyu; Li, Yongxue; Wu, Jiangang

2018-05-30

Medical injection pump is a commonly used clinical equipment with high risk. Accurate detection of flow is an important aspect to ensure its reliable operation. In this paper, we carefully studied and analyzed the flow detection methods of three standards being used in medical injection pump detection in our country. The three standards were compared from the aspects of standard device, flow test point selection, length of test time and accuracy judgment. The advantages and disadvantages of these standards were analyzed and suggestions for improvement were put forward.

Emulsification kinetics during quasi-miscible flow in dead-end pores

NASA Astrophysics Data System (ADS)

Broens, M.; Unsal, E.

2018-03-01

Microemulsions have found applications as carriers for the transport of solutes through various porous media. They are commonly pre-prepared in bulk form, and then injected into the medium. The preparation is done by actively mixing the surfactant, water and oil, and then allowing the mixture to stagnate until equilibrium is reached. The resulting microemulsion characteristics of the surfactant/oil/water system are studied at equilibrium conditions, and perfect mixing is assumed. But in applications like subsurface remediation and enhanced oil recovery, microemulsion formation may occur in the pore space. Surfactant solutions are injected into the ground to solubilize and/or mobilize the non-aqueous phase liquids (NAPLs) by in-situ emulsification. Flow dynamics and emulsification kinetics are coupled, which also contributes to in-situ mixing. In this study, we investigated the nature of such coupling for a quasi-miscible fluid system in a conductive channel with dead-end extensions. A microfluidic setup was used, where an aqueous solution of an anionic, internal olefin sulfonate 20-24 (IOS) surfactant was injected into n-decane saturated glass micromodel. The oil phase was coloured using a solvatochromatic dye allowing for direct visualization of the aqueous and oil phases as well as their microemulsions under fluorescent light. Presence of both conductive and stagnant dead-end channels in a single pore system made it possible to isolate different transport mechanisms from each other but also allowed to study the transitions from one to the other. In the conductive channel, the surfactant was carried with flow, and emulsification was controlled by the localized flow dynamics. In the stagnant zones, the driving force of the mass transfer was driven by the chemical concentration gradient. Some of the equilibrium phase behaviour characteristics of the surfactant/oil/water system were recognisable during the quasi-miscible displacement. However, the equilibrium tests alone were not sufficient to predict the emulsification process under dynamic conditions.

Flow visualization of film cooling with spanwise injection from a small array of holes and compound-angle injection from a large array

NASA Technical Reports Server (NTRS)

Russell, L. M.

1978-01-01

Film injection from discrete holes in a smooth, flat plate was studied for two configurations: (1) spanwise injection through a four hole staggered array; and (2) compound angle injection through a 49 hole staggered array. The ratio of boundary layer thicknesses to hole diameter and the Reynolds number were typical of gas turbine film cooling applications. Streaklines showing the motion of the injected air were obtained by photographing small, neutrally buoyant, helium-filled soap bubbles that followed the flow field.

Instrumental Implementation of an Experiment to Demonstrate αω -dynamos in Accretion Disks

NASA Astrophysics Data System (ADS)

Si, Jiahe; Sonnenfeld, Richard; Colgate, Art; Li, Hui; Nornberg, Mark

2016-10-01

The New Mexico Liquid Metal αω -dynamo experiment is aimed to demonstrate a galactic dynamo. Our goal is to generate the ω-effect and α-effect by two semi-coherent flows in laboratory. Two coaxial cylinders are used to generate Taylor-Couette flows to simulate the differential rotation of accretion disks. Plumes induced by jets injected into the Couette flows are expected to produce helicities necessary for the α-effect. We have demonstrated an 8-fold poloidal-to-toroidal flux amplification from differential rotation (the ω-effect) by minimizing turbulence in our apparatus. To demonstrate the α-effect, the experimental apparatus is undergoing significant upgrade. We have constructed a helicity injection facility, and are also designing and testing a new data acquisition system capable of transmitting data in a high speed rotating frame. Additional magnetic field diagnostics will also be included. The upgrade is intended to answer the question of whether a self-sustaining αω -dynamo can be constructed with a realistic fluid flow field, as well as to obtain more details to understand dynamo action in highly turbulent Couette flow.

Experimental investigation of nozzle/plume aerodynamics at hypersonic speeds

NASA Technical Reports Server (NTRS)

Bogdanoff, David W.; Cambier, Jean-Luc; Papadopoulos, Perikles

1994-01-01

Much of the work involved the Ames 16-Inch Shock Tunnel facility. The facility was reactivated and upgraded, a data acquisition system was configured and upgraded several times, several facility calibrations were performed and test entries with a wedge model with hydrogen injection and a full scramjet combustor model, with hydrogen injection, were performed. Extensive CFD modeling of the flow in the facility was done. This includes modeling of the unsteady flow in the driver and driven tubes and steady flow modeling of the nozzle flow. Other modeling efforts include simulations of non-equilibrium flows and turbulence, plasmas, light gas guns and the use of non-ideal gas equations of state. New experimental techniques to improve the performance of gas guns, shock tubes and tunnels and scramjet combustors were conceived and studied computationally. Ways to improve scramjet engine performance using steady and pulsed detonation waves were also studied computationally. A number of studies were performed on the operation of the ram accelerator, including investigations of in-tube gasdynamic heating and the use of high explosives to raise the velocity capability of the device.

Control of impurities in toroidal plasma devices

DOEpatents

Ohkawa, Tihiro

1980-01-01

A method and apparatus for plasma impurity control in closed flux plasma systems such as Tokamak reactors is disclosed. Local axisymmetrical injection of hydrogen gas is employed to reverse the normally inward flow of impurities into the plasma.

Flow-injection assay of catalase activity.

PubMed

Ukeda, Hiroyuki; Adachi, Yukiko; Sawamura, Masayoshi

2004-03-01

A novel flow-injection assay (FIA) system with a double line for catalase activity was constructed in which an oxidase is immobilized and the substrate is continuously pumped to reduce the dissolved oxygen and to generate a given level of hydrogen peroxide. The catalase in a sample decomposed the hydrogen peroxide, and thus the increase in dissolved oxygen dependent on the activity was amperometrically monitored using a Clark-type oxygen electrode. Among the examined several oxidases, uricase was most suitable for the continuous formation of hydrogen peroxide from a consideration of the stability and the conversion efficiency. Under the optimum conditions, a linear calibration curve was obtained in the range from 21 to 210 units/mg and the reproducibility (CV) was better than 2% by 35 successive determinations of 210 units/ml catalase preparation. The sampling frequency was about 15 samples/h. The present FIA system was applicable to monitor the inactivation of catalase by glycation.

A microfluidic investigation of gas exsolution in glass and shale fracture networks

NASA Astrophysics Data System (ADS)

Porter, M. L.; Jimenez-Martinez, J.; Harrison, A.; Currier, R.; Viswanathan, H. S.

2016-12-01

Microfluidic investigations of pore-scale fluid flow and transport phenomena has steadily increased in recent years. In these investigations fluid flow is restricted to two-dimensions allowing for real-time visualization and quantification of complex flow and reactive transport behavior, which is difficult to obtain in other experimental systems. In this work, we describe a unique high pressure (up to 10.3 MPa) and temperature (up to 80 °C) microfluidics experimental system that allows us to investigate fluid flow and transport in geo-material (e.g., shale, Portland cement, etc.) micromodels. The use of geo-material micromodels allows us to better represent fluid-rock interactions including wettability, chemical reactivity, and nano-scale porosity at conditions representative of natural subsurface environments. Here, we present experimental results in fracture systems with applications to hydrocarbon mobility in fractured rocks. Complex fracture network patterns are derived from 3D x-ray tomography images of actual fractures created in shale rock cores. We use both shale and glass micromodels, allowing for a detailed comparison between flow phenomena in the different materials. We discuss results from two-phase gas (CO2 and N2) injection experiments designed to enhance oil recovery. In these experiments gas was injected into micromodels saturated with oil and allowed to soak for approximately 12 hours at elevated pressures. The pressure in the system was then decreased to atmospheric, causing the gas to expand and/or dissolve out of solution, subsequently mobilizing the oil. In addition to the experimental results, we present a relatively simple model designed to quantify the amount of oil mobilized as a function of decreasing system pressure. We will show comparisons between the experiments and model, and discuss the potential use of the model in field-scale reservoir simulations.

Gain and temperature in a slit nozzle supersonic chemical oxygen-iodine laser with transonic and supersonic injection of iodine

NASA Astrophysics Data System (ADS)

Rosenwaks, Salman; Barmashenko, Boris D.; Bruins, Esther; Furman, Dov; Rybalkin, Victor; Katz, Arje

2002-05-01

Spatial distributions of the gain and temperament across the flow were studied for transonic and supersonic schemes of the iodine injection in a slit nozzle supersonic chemical oxygen-iodine laser as a function of the iodine and secondary nitrogen flow rate, jet penetration parameter and gas pumping rate. The mixing efficiency for supersonic injection of iodine is found to be much larger than for transonic injection, the maximum values of the gain being approximately 0.65 percent/cm for both injection schemes. Measurements of the gain distribution as a function of the iodine molar flow rate nI2 were carried out. For transonic injection the optimal value of nI2 at the flow centerline is smaller than that at the off axis location. The temperature is distributed homogeneously across the flow, increasing only in the narrow boundary layers near the walls. Opening a leak downstream of the cavity in order to decease the Mach number results in a decrease of the gain and increase of the temperature. The mixing efficiency in this case is much larger than for closed leak.

Velocity field of a round jet in a cross flow for various jet injection angles and velocity ratios. [Langley V/STOL tunnel

NASA Technical Reports Server (NTRS)

Fearn, R. L.; Weston, R. P.

1979-01-01

A subsonic round jet injected from a flat plate into a subsonic crosswind of the same temperature was investigated. Velocity and pressure measurements in planes perpendicular to the path of the jet were made for nominal jet injection angles of 45 deg, 60 deg, 75 deg, 90 deg, and 105 deg and for jet/cross flow velocity ratios of four and eight. The velocity measurements were obtained to infer the properties of the vortex pair associated with a jet in a cross flow. Jet centerline and vortex trajectories were determined and fit with an empirical equation that includes the effects of jet injection angle, jet core length, and jet/cross flow velocity ratios.

Fast "hyperlayer" separation development in sedimentation field flow fractionation.

PubMed

Kassab, James R; Cardot, Philippe J P; Zahoransky, Richard A; Battu, Serge

2005-11-05

Specific prototypes of sedimentation field flow fractionation devices (SdFFF) have been developed with relative success for cell sorting. However, no data are available to compare these apparatus with commercial ones. In order to compare with other devices mainly used for non-biological species, biocompatible systems were used for standard particle (latex: 3-10 microm of different size dispersities) separation development. In order to enhance size dependent separations, channels of reduced thickness were used (80 and 100 microm) and channel/carrier-phase equilibration procedures were necessary. For sample injection, the use of inlet tubing linked to the FFF accumulation wall, common for cell sorting, can be extended to latex species when they are eluted in the Steric Hyperlayer elution mode. It avoids any primary relaxation steps (stop flow injection procedure) simplifying series of elution processing. Mixtures composed of four different monodispersed latex beads can be eluted in 6 min with 100 microm channel thickness.

Hexagonal convection patterns and their evolutionary scenarios in electroconvection induced by a strong unipolar injection

NASA Astrophysics Data System (ADS)

Luo, Kang; Wu, Jian; Yi, Hong-Liang; Liu, Lin-Hua; Tan, He-Ping

2018-05-01

A regular hexagonal pattern of three-dimensional electroconvective flow induced by unipolar injection in dielectric liquids is numerically observed by solving the fully coupled governing equations using the lattice Boltzmann method. A small-amplitude perturbation in the form of a spatially periodic pattern of hexagonal cells is introduced initially. The transient development of convective cells that undergo a sequence of transitions agrees with the idea of flow seeking an optimal scale. Stable hexagonal convective cells and their subcritical bifurcation together with a hysteresis loop are clearly observed. In addition, the stability of the hexagonal flow pattern is analyzed in a wide range of relevant parameters, including the electric Rayleigh number T , nondimensional mobility M , and wave number k . It is found that centrally downflowing hexagonal cells, which are characterized by the central region being empty of charge, are preferred in the system.

Theory of plasma contractors for electrodynamic tethered satellite systems

NASA Technical Reports Server (NTRS)

Parks, D. E.; Katz, I.

1986-01-01

Recent data from ground and space experiments indicate that plasma releases from an object dramatically reduce the sheath impedance between the object and the ambient plasma surrounding it. Available data is in qualitative accord with the theory developed to quantify the flow of current in the sheath. Electron transport in the theory is based on a fluid model of a collisionless plasma with an effective collision frequency comparable to frequencies of plasma oscillations. The theory leads to low effective impedances varying inversely with the square root of the injected plasma density. To support such a low impedance mode of operation using an argon plasma source for example requires that only one argon ion be injected for each thirty electrons extracted from the ambient plasma. The required plasma flow rates are quite low; to extract one ampere of electron current requires a mass flow rate of about one gram of argon per day.

Studies of the haemodynamic effects of creatine phosphate in man.

PubMed Central

Hurlow, R A; Aukland, A; Hardman, J; Whittington, J R

1982-01-01

1 The haemodynamic effects of intravenous creatine phosphate 1000 mg have been studied. 2 During the first 60 min following drug administration heart rate and blood pressure did not change but cardiac output fell significantly by approximately 18%. Calculated total peripheral resistance showed a corresponding significant rise, the maximum increase being approximately 24%. All these changes were beginning to diminish within 90 min after the injection. 3 Total limb blood flow measured in both arm and leg (using venous occlusion strain-gauge plethysmography) showed no appreciable changes following injection of creatine phosphate. 4 There was a progressive reduction in leg muscle blood flow (Xe133 clearance method) following injection which was statistically significant with respect to the initial level and reached a minimum (46% reduction) 50 min after the injection. 5 Skin blood flow, estimated by infra-red photoplethysmography, showed changes complementary to those seen with muscle flow. There was a progressive and significant rise to a peak (73% increase) 30 min after the injection. 6 No adverse reactions to the injections were noted. 7 Reduced cardiac output in the absence of altered total limb blood flow presumably reflects a reduction in visceral blood flow, which was not measured in this study. Within the limbs, creatine phosphate appears to result in a redistribution of blood flow from muscle to skin. Thus, these preliminary results suggest that intravenous creatine phosphate could be clinically useful in situations where short term improvement in skin blood flow would be advantageous and that further controlled studies would be justified. PMID:7093109

Enhancing the use of coals by gas reburning-sorbent injection. Volume 3, Gas reburning-sorbent injection at Edwards Unit 1, Central Illinois Light Company

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1994-10-01

Design work has been completed for a Gas Reburning-Sorbent Injection (GR-SI) system to reduce emissions of NO{sub x}, and SO{sub 2} from a wall fired unit. A GR-SI system was designed for Central Illinois Light Company`s Edwards Station Unit 1, located in Bartonville, Illinois. The unit is rated at 117 MW(e) (net) and is front wall fired with a pulverized bituminous coal blend. The goal of the project was to reduce emissions of NO{sub x} by 60%, from the ``as found`` baseline of 0.98 lb/MBtu (420 mg/MJ), and to reduce emissions of S0{sub 2} by 50%. Since the unit currentlymore » fires a blend of high sulfur Illinois coal and low sulfur Kentucky coal to meet an S0{sub 2} limit Of 1.8 lb/MBtu (770 mg/MJ), the goal at this site was amended to meeting this limit while increasing the fraction of high sulfur coal to 57% from the current 15% level. GR-SI requires injection of natural gas into the furnace at the level of the top burner row, creating a fuel-rich zone in which NO{sub x} formed in the coal zone is reduced to N{sub 2}. The design natural gas input corresponds to 18% of the total heat input. Burnout (overfire) air is injected at a higher elevation to burn out fuel combustible matter at a normal excess air level of 18%. Recycled flue gas is used to increase the reburning fuel jet momentum, resulting in enhanced mixing. Recycled flue gas is also used to cool the top row of burners which would not be in service during GR operation. Dry hydrated lime sorbent is injected into the upper furnace to react with S0{sub 2}, forming solid CaSO{sub 4} and CaSO{sub 3}, which are collected by the ESP. The SI system design was optimized with respect to gas temperature, injection air flow rate, and sorbent dispersion. Sorbent injection air flow is equal to 3% of the combustion air. The design includes modifications of the ESP, sootblowing, and ash handling systems.« less

Design and integration of a generic disposable array-compatible sensor housing into an integrated disposable indirect microfluidic flow injection analysis system.

PubMed

Rapp, Bastian E; Schickling, Benjamin; Prokop, Jürgen; Piotter, Volker; Rapp, Michael; Länge, Kerstin

2011-10-01

We describe an integration strategy for arbitrary sensors intended to be used as biosensors in biomedical or bioanalytical applications. For such devices ease of handling (by a potential end user) as well as strict disposable usage are of importance. Firstly we describe a generic array compatible polymer sensor housing with an effective sample volume of 1.55 μl. This housing leaves the sensitive surface of the sensor accessible for the application of biosensing layers even after the embedding. In a second step we show how this sensor housing can be used in combination with a passive disposable microfluidic chip to set up arbitrary 8-fold sensor arrays and how such a system can be complemented with an indirect microfluidic flow injection analysis (FIA) system. This system is designed in a way that it strictly separates between disposable and reusable components- by introducing tetradecane as an intermediate liquid. This results in a sensor system compatible with the demands of most biomedical applications. Comparative measurements between a classical macroscopic FIA system and this integrated indirect microfluidic system are presented. We use a surface acoustic wave (SAW) sensor as an exemplary detector in this work.

Insights on Flow Behavior of Foam in Unsaturated Porous Media during Soil Flushing.

PubMed

Zhao, Yong S; Su, Yan; Lian, Jing R; Wang, He F; Li, Lu L; Qin, Chuan Y

2016-11-01

  One-dimensional column and two-dimensional tank experiments were carried out to determine (1) the physics of foam flow and propagation of foaming gas, foaming liquid, and foam; (2) the pressure distribution along foam flow and the effect of media permeability, foam flow rate and foam quality on foam injection pressure; and (3) the migration and distribution property of foam flow in homogeneous and heterogeneous sediments. The results demonstrated that: (1) gas and liquid front were formed ahead of the foam flow front, the transport speed order is foaming gas > foaming liquid > foam flowing; (2) injection pressure mainly comes from the resistance to bubble migration. Effect of media permeability on foam injection pressure mainly depends on the physics and behavior of foam flow; (3) foam has a stronger capacity of lateral spreading, besides, foam flow was uniformly distributed across the foam-occupied region, regardless of the heterogeneity of porous media.

Numerical investigation of the air injection effect on the cavitating flow in Francis hydro turbine

NASA Astrophysics Data System (ADS)

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.

Geochemical modelling of EGS fracture stimulation applying weak and strong acid treatments

NASA Astrophysics Data System (ADS)

Sigfusson, Bergur; Sif Pind Aradottir, Edda

2015-04-01

Engineered Geothermal systems (EGS) provide geothermal power by tapping into the Earth's deep geothermal resources that are otherwise not exploitable due to lack of water and fractures, location or rock type. EGS technologies have the potential to cost effectively produce large amounts of electricity almost anywhere in the world. The EGS technology creates permeability in the rock by hydro-fracturing the reservoir with cold water pumped into the first well (the injection well) at a high pressure. The second well (the production well) intersects the stimulated fracture system and returns the hot water to the surface where electricity can be generated. A significant technological hurdle is ensuring effective connection between the wells and the fracture system and to control the deep-rooted fractures (can exceed 5 000 m depth). A large area for heat transfer and sufficient mass flow needs to be ensured between wells without creating fast flowing paths in the fracture network. Maintaining flow through the fracture system can cause considerable energy penalty to the overall process. Therefore, chemical methods to maintain fractures and prevent scaling can be necessary to prevent excessive pressure build up in the re-injection wells of EGS systems. The effect of different acid treatments on the porosity development of selected rock types was simulated with the aid of the Petrasim interface to the Toughreact simulation code. The thermodynamic and kinetic database of Aradottir et al. (2014) was expanded to include new minerals and the most important fluoride bearing species involved in mineral reactions during acid stimulation of geothermal systems. A series of simulations with injection waters containing fluoric acid, hydrochloric acid and CO2 or mixtures thereof were then carried out and porosity development in the fracture system monitored. The periodic injection of weak acid mixtures into EGS systems may be cost effective in some isolated cases to prevent pressure build-up and therefore lowering pumping costs during operation. Selection of the acid is though highly dependent on the chemistry of the reservoir in question. Reference Aradottir, E. S. P., Gunnarsson, I., Sigfusson, B., Gunnarsson, G., Juliusson, B. M., Gunnlaugsson, E., Sigurdardóttir, H., Arnarson, M. T., Sonnenthal, E., 2014. Toward Cleaner Geothermal Energy Utilization: Capturing and Sequestering CO2 and H2S Emissions from Geothermal Power Plants. Transport in Porous Media. DOI 10.1007s/11242-014-0316-5

Reverse-Tangent Injection in a Centrifugal Compressor

NASA Technical Reports Server (NTRS)

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.

Simulation of the impact of managed aquifer recharge on the groundwater system in Hanoi, Vietnam

NASA Astrophysics Data System (ADS)

Glass, Jana; Via Rico, Daniela A.; Stefan, Catalin; Nga, Tran Thi Viet

2018-05-01

A transient numerical groundwater flow model using MODFLOW-NWT was set up and calibrated for Hanoi city, Vietnam, to understand the local groundwater flow system and to suggest solutions for sustainable water resource management. Urban development in Hanoi has caused a severe decline of groundwater levels. The present study evaluates the actual situation and investigates the suitability of managed aquifer recharge (MAR) to stop further depletion of groundwater resources. The results suggest that groundwater is being overexploited, as vast cones of depression exist in parts of the study area. Suitable locations to implement two MAR techniques—riverbank filtration and injection wells—were identified using multi-criteria decision analysis based on geographic information system (GIS). Three predictive scenarios were simulated. The relocation of pumping wells towards the Red River to induce riverbank filtration (first scenario) demonstrates that groundwater levels can be increased, especially in the depression cones. Groundwater levels can also be improved locally by the infiltration of surplus water into the upper aquifer (Holocene) via injection wells during the rainy season (second scenario), but this is not effective to raise the water table in the depression cones. Compared to the first scenario, the combination of riverbank filtration and injection wells (third scenario) shows a slightly raised overall water table. Groundwater flow modeling suggests that local overexploitation can be stopped by a smart relocation of wells from the main depression cones and the expansion of riverbank filtration. This could also avoid further land subsidence while the city's water demand is met.

NUMERICAL SIMULATIONS OF HELICITY CONDENSATION IN THE SOLAR CORONA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, L.; Zurbuchen, T. H.; DeVore, C. R.

The helicity condensation model has been proposed by Antiochos to explain the observed smoothness of coronal loops and the observed buildup of magnetic shear at filament channels. The basic hypothesis of the model is that magnetic reconnection in the corona causes the magnetic stress injected by photospheric motions to collect only at those special locations where prominences are observed to form. In this work we present the first detailed quantitative MHD simulations of the reconnection evolution proposed by the helicity condensation model. We use the well-known ansatz of modeling the closed corona as an initially uniform field between two horizontalmore » photospheric plates. The system is driven by applying photospheric rotational flows that inject magnetic helicity into the corona. The flows are confined to a finite region on the photosphere so as to mimic the finite flux system of a bipolar active region, for example. The calculations demonstrate that, contrary to common belief, opposite helicity twists do not lead to significant reconnection in such a coronal system, whereas twists with the same sense of helicity do produce substantial reconnection. Furthermore, we find that for a given amount of helicity injected into the corona, the evolution of the magnetic shear is insensitive to whether the pattern of driving photospheric motions is fixed or quasi-random. In all cases, the shear propagates via reconnection to the boundary of the flow region while the total magnetic helicity is conserved, as predicted by the model. We discuss the implications of our results for solar observations and for future, more realistic simulations of the helicity condensation process.« less

Comparison of two methods for selegiline determination: A flow-injection chemiluminescence method using cadmium sulfide quantum dots and corona discharge ion mobility spectrometry.

PubMed

Khataee, Alireza; Lotfi, Roya; Hasanzadeh, Aliyeh; Iranifam, Mortaza; Zarei, Mahmoud; Joo, Sang Woo

2016-01-15

Two analytical approaches including chemiluminescence (CL) and corona discharge ionization ion mobility spectrometry (CD-IMS) were developed for sensitive determination of selegiline (SG). We found that the CL intensity of the KMnO4-Na2S2O3 CL system was significantly enhanced in the presence of L-cysteine capped CdS quantum dots (QDs). A possible CL mechanism for this CL reaction is proposed. In the presence of SG, the enhanced CL system was inhibited. Based on this inhibition, a simple and sensitive flow-injection CL method was proposed for the determination of SG. Under optimum experimental conditions, the decreased CL intensity was proportional to SG concentration in the range of 0.01 to 30.0 mg L(-1). The detection limit (3σ) was 0.004 mg L(-1). Also, SG was determined using CD-IMS, and under optimum conditions of CD-IMS, calibration curves were linear in the range of 0.15 to 42.0 mg L(-1), with a detection limit (3σ) of 0.03 mg L(-1). The precision of the two methods was calculated by analyzing samples containing 5.0 mg L(-1) of SG (n=11). The relative standard deviations (RSDs%) of the flow-injection CL and CD-IMS methods are 2.17% and 3.83%, respectively. The proposed CL system exhibits a higher sensitivity and precision than the CD-IMS method for the determination of SG. Copyright © 2015. Published by Elsevier B.V.

Computational flow field in energy efficient engine (EEE)

NASA Astrophysics Data System (ADS)

Miki, Kenji; Moder, Jeff; Liou, Meng-Sing

2016-11-01

In this paper, preliminary results for the recently-updated Open National Combustor Code (Open NCC) as applied to the EEE are presented. The comparison between two different numerical schemes, the standard Jameson-Schmidt-Turkel (JST) scheme and the advection upstream splitting method (AUSM), is performed for the cold flow and the reacting flow calculations using the RANS. In the cold flow calculation, the AUSM scheme predicts a much stronger reverse flow in the central recirculation zone. In the reacting flow calculation, we test two cases: gaseous fuel injection and liquid spray injection. In the gaseous fuel injection case, the overall flame structures of the two schemes are similar to one another, in the sense that the flame is attached to the main nozzle, but is detached from the pilot nozzle. However, in the exit temperature profile, the AUSM scheme shows a more uniform profile than that of the JST scheme, which is close to the experimental data. In the liquid spray injection case, we expect different flame structures in this scenario. We will give a brief discussion on how two numerical schemes predict the flame structures inside the Eusing different ways to introduce the fuel injection. Supported by NASA's Transformational Tools and Technologies project.

Computational Flow Field in Energy Efficient Engine (EEE)

NASA Technical Reports Server (NTRS)

Miki, Kenji; Moder, Jeff; Liou, Meng-Sing

2016-01-01

In this paper, preliminary results for the recently-updated Open National Combustion Code (Open NCC) as applied to the EEE are presented. The comparison between two different numerical schemes, the standard Jameson-Schmidt-Turkel (JST) scheme and the advection upstream splitting method (AUSM), is performed for the cold flow and the reacting flow calculations using the RANS. In the cold flow calculation, the AUSM scheme predicts a much stronger reverse flow in the central recirculation zone. In the reacting flow calculation, we test two cases: gaseous fuel injection and liquid spray injection. In the gaseous fuel injection case, the overall flame structures of the two schemes are similar to one another, in the sense that the flame is attached to the main nozzle, but is detached from the pilot nozzle. However, in the exit temperature profile, the AUSM scheme shows a more uniform profile than that of the JST scheme, which is close to the experimental data. In the liquid spray injection case, we expect different flame structures in this scenario. We will give a brief discussion on how two numerical schemes predict the flame structures inside the EEE using different ways to introduce the fuel injection.

Supersonic Pulsed Injection

NASA Technical Reports Server (NTRS)

Cutler, A. D.; Harding, G. C.; Diskin, G. S.

2001-01-01

An injector has been developed to provide high-speed high-frequency (order 10 kHz) pulsed a supersonic crossflow. The injector nozzle is formed between the fixed internal surface of the nozzle and a freely rotating three- or four-sided wheel embedded within the device. Flow-induced rotation of the wheel causes the nozzle throat to open and close at a frequency proportional to the speed of sound of the injected gas. Measurements of frequency and mass flow rate as a function of supply pressure are discussed for various injector designs. Preliminary results are presented for wall-normal injection of helium into a Mach-2 ducted airflow. The data include schlieren images in the injectant plume in a plane normal to the flow, downstream of injection.

Film cooling effectiveness and heat transfer with injection through holes

NASA Technical Reports Server (NTRS)

Eriksen, V. L.

1971-01-01

An experimental investigation of the local film cooling effectiveness and heat transfer downstream of injection of air through discrete holes into a turbulent boundary layer of air on a flat plate is reported. Secondary air is injected through a single hole normal to the main flow and through both a single hole and a row of holes spaced at three diameter intervals with an injection angle of 35 deg to the main flow. Two values of the mainstream Reynolds number are used; the blowing rate is varied from 0.1 to 2.0. Photographs of a carbon dioxide-water fog injected into the main flow at an angle of 90 deg are also presented to show interaction between the jet and mainstream.

Post-Injection Induced Seismicity in EGS: Triggering Mechanisms and Mitigation.

NASA Astrophysics Data System (ADS)

De Simone, S.; Carrera, J.; Vilarrasa, V.

2017-12-01

Induced microseismicity is a controversial issue related to Enhanced Geothermal Systems (EGS) and in general with fluid injection into deep geological formations. The occurring of felt earthquakes after stopping injection especially generates concern, because the correlation between injection and seismic activity is unclear. The aim of this work is to advance in the understanding of the processes that may induce or trigger co- and post-injection seismicity. To this end we investigate the thermo-hydro-mechanical coupling by means of numerical simulations of hydraulic stimulation of deep geothermal systems. We find that preferential flow through conductive fractures or fault zones provokes pressure and temperature perturbations that result in not only heterogeneous variation of the stress field, but also highly anisotropic variations of the local stress tensor. Anisotropic variations tend to stabilize some fractures, but destabilize others. Moreover, activation of shear slip causes a significant variation of the stress field that enlarges the range of critical fracture orientations. We find that post-injection seismicity may occur on non-critically oriented faults that were originally stable. During injection, such faults become destabilized by thermal and shear slip stress changes, but remain static by the superposition of the stabilizing effect of pressure forces. However, these fractures become unstable and fail when the pressure forcing dissipates shortly after injection stops abruptly, which suggests that a slow reduction in injection rate may mitigate post-injection seismicity.

Flow in a discrete slotted nozzle with massive injection. [water table tests

NASA Technical Reports Server (NTRS)

Perkins, H. C.

1974-01-01

An experimental investigation has been conducted to determine the effect of massive wall injection on the flow characteristics in a slotted nozzle. Some of the experiments were performed on a water table with a slotted-nozzle test section. This has 45 deg and 15 deg half angles of convergence and divergence, respectively, throat radius of 2.5 inches, and throat width of 3 inches. The hydraulic analogy was employed to qualitatively extend the results to a compressible gas flow through the nozzle. Experimental results from the water table include contours of constant Froude and Mach number with and without injection. Photographic results are also presented for the injection through slots of CO2 and Freon-12 into a main-stream air flow in a convergent-divergent nozzle in a wind tunnel. Schlieren photographs were used to visualize the flow, and qualititative agreement between the results from the gas tunnel and water table is good.

Feasibility Study for The Setting Up of a Safety System for Monitoring CO2 Storage at Prinos Field, Greece

NASA Astrophysics Data System (ADS)

Koukouzas, Nikolaos; Lymperopoulos, Panagiotis; Tasianas, Alexandros; Shariatipour, Seyed

2016-10-01

Geological storage of CO2 in subsurface geological structures can mitigate global warming. A comprehensive safety and monitoring system for CO2 storage has been undertaken for the Prinos hydrocarbon field, offshore northern Greece; a system which can prevent any possible leakage of CO2. This paper presents various monitoring strategies of CO2 subsurface movement in the Prinos reservoir, the results of a simulation of a CO2 leak through a well, an environmental risk assessment study related to the potential leakage of CO2 from the seafloor and an overall economic insight of the system. The results of the simulation of the CO2 leak have shown that CO2 reaches the seabed in the form of gas approximately 13.7 years, from the beginning of injection. From that point onwards the amount of CO2 reaching the seabed increases until it reaches a peak at around 32.9 years. During the injection period, the CO2 plume develops only within the reservoir. During the post-injection period, the CO2 reaches the seabed and develops side branches. These correspond to preferential lateral flow pathways of the CO2 and are more extensive for the dissolved CO2 than for the saturated CO2 gas. For the environmental risk assessment, we set up a model, using ArcGIS software, based on the use of data regarding the speeds of the winds and currents encountered in the region. We also made assumptions related to the flow rate of CO2. Results show that after a period of 10 days from the start of CO2 leakage the CO2 has reached halfway to the continental shores where the “Natura” protected areas are located. CO2 leakage modelling results show CO2 to be initially flowing along a preferential flow direction, which is towards the NE. However, 5 days after the start of leakage of CO2, the CO2 is also flowing towards the ENE. The consequences of a potential CO2 leak are considered spatially limited and the ecosystem is itself capable of recovering. We have tried to determine the costs necessary for the creation of such an integrated CO2 monitoring program both during the CO2 injection phase as well as during permanent storage. The most prevalent solution consists of purchasing both seismic equipment and Echosounder systems as well as privileging a monitoring system, which uses selected boreholes. The necessary period required for monitoring the study area is at least 20 years after the end of the CO2 storage period at Prinos. To the overall monitoring time, we should also add a further 20 years that are required for the injection phase as well as 12 years for the storage phase. The operating costs for monitoring the CO2 amount to 0,38 /ton CO2 and the total cost for EOR at Prinos amounts to 0,45 /ton CO2.

Flow Injection Analysis and Liquid Chromatography for Multifunctional Chemical Analysis (MCA) Systems

ERIC Educational Resources Information Center

Mayo, Ana V.; Loegel, Thomas N.; Bretz, Stacey Lowery; Danielson, Neil D.

2013-01-01

The large class sizes of first-year chemistry labs makes it challenging to provide students with hands-on access to instrumentation because the number of students typically far exceeds the number of research-grade instruments available to collect data. Multifunctional chemical analysis (MCA) systems provide a viable alternative for large-scale…

Reductions in Multi-Component Jet Noise by Water Injection

NASA Technical Reports Server (NTRS)

Norum, Thomas D.

2004-01-01

An experimental investigation was performed in the NASA Langley Low Speed Aeroacoustics Wind Tunnel to determine the extent of jet exhaust noise reduction that can be obtained using water injection in a hot jet environment. The effects of water parameters such as mass flow rate, injection location, and spray patterns on suppression of dominant noise sources in both subsonic and supersonic jets were determined, and extrapolations to full-scale engine noise reduction were made. Water jets and sprays were injected in to the shear layers of cold and hot circular jets operating at both subsonic and supersonic exhaust conditions. Use of convergent-divergent and convergent nozzles (2.7in. D) allowed for simulations of all major jet noise sources. The experimental results show that water injection clearly disrupts shock noise sources within the jet plume, with large reductions in radiated shock noise. There are smaller reductions in jet mixing noise, resulting in only a small decrease in effective perceived noise level when projections are made to full scale. The fact that the measured noise reduction in the direction upstream of the nozzle was consistently larger than in the noisier downstream direction contributed to keeping effective perceived noise reductions small. Variations in the operation of the water injection system clearly show that injection at the nozzle exit rather than further downstream is required for the largest noise reduction. Noise reduction increased with water pressure as well as with its mass flow, although the type of injector had little effect.

THERMAL-ENERGY STORAGE IN A DEEP SANDSTONE AQUIFER IN MINNESOTA: FIELD OBSERVATIONS AND THERMAL ENERGY-TRANSPORT MODELING.

USGS Publications Warehouse

Miller, R.T.

1986-01-01

A study of the feasibility of storing heated water in a deep sandstone aquifer in Minnesota is described. The aquifer consists of four hydraulic zones that are areally anisotropic and have average hydraulic conductivities that range from 0. 03 to 1. 2 meters per day. A preliminary axially symmetric, nonisothermal, isotropic, single-phase, radial-flow, thermal-energy-transport model was constructed to investigate the sensitivity of model simulation to various hydraulic and thermal properties of the aquifer. A three-dimensional flow and thermal-energy transport model was constructed to incorporate the areal anisotropy of the aquifer. Analytical solutions of equations describing areally anisotropic groundwater flow around a doublet-well system were used to specify model boundary conditions for simulation of heat injection. The entire heat-injection-testing period of approximately 400 days was simulated. Model-computed temperatures compared favorably with field-recorded temperatures, with differences of no more than plus or minus 8 degree C. For each test cycle, model-computed aquifer thermal efficiency, defined as total heat withdrawn divided by total heat injected, was within plus or minus 2% of the field-calculated values.

Mid-infrared quantum cascade lasers for flow injection analysis

PubMed

Lendl; Frank; Schindler; Muller; Beck; Faist

2000-04-01

A Fabry-Perot quantum cascade laser (QCL) was used as a powerful light source for mid infrared (MIR) detection in flow injection analysis. The QCL lased at several wavelengths close to each other within a few wavenumbers (990-1010 cm-1), hence fitting well to the broad absorption bands of molecules in liquid phase. As compared with that of a state-of-the-art Fourier transform spectrometer, the signal-to-noise ratio could be improved by a factor of 50. Additionally, by using a QCL as the light source, optical path lengths of more than 100 microns could be used even in aqueous matrixes which reduced the danger of cell clogging. In the example shown here phosphate was determined in Diet Coke samples. The flow injection system used allowed the measurement of the sample at two pH values (5 and 13) at which the analyte was present as H2PO4- and PO4(3-), respectively. As the analytical readout the difference in IR absorption of H2PO4- and PO4(3-) at the laser wavelengths was taken. The FIA-QCL measurements were corroborated by ion chromatography which was used as a reference method.

Polyion selective polymeric membrane-based pulstrode as a detector in flow-injection analysis.

PubMed

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.

Cavitation Inside High-Pressure Optically Transparent Fuel Injector Nozzles

NASA Astrophysics Data System (ADS)

Falgout, Z.; Linne, M.

2015-12-01

Nozzle-orifice flow and cavitation have an important effect on primary breakup of sprays. For this reason, a number of studies in recent years have used injectors with optically transparent nozzles so that orifice flow cavitation can be examined directly. Many of these studies use injection pressures scaled down from realistic injection pressures used in modern fuel injectors, and so the geometry must be scaled up so that the Reynolds number can be matched with the industrial applications of interest. A relatively small number of studies have shown results at or near the injection pressures used in real systems. Unfortunately, neither the specifics of the design of the optical nozzle nor the design methodology used is explained in detail in these papers. Here, a methodology demonstrating how to prevent failure of a finished design made from commonly used optically transparent materials will be explained in detail, and a description of a new design for transparent nozzles which minimizes size and cost will be shown. The design methodology combines Finite Element Analysis with relevant materials science to evaluate the potential for failure of the finished assembly. Finally, test results imaging a cavitating flow at elevated pressures are presented.

Study on cyclic injection gas override in condensate gas reservoir

NASA Astrophysics Data System (ADS)

Sun, Yan; Zhu, Weiyao; Xia, Jing; Li, Baozhu

2018-02-01

Cyclic injection gas override in condensate gas reservoirs for the large density difference between injection gas and condensate gas has been studied, but no relevant mathematical models have been built. In this paper, a mathematical model of cyclic injection gas override in condensate gas reservoir is established, considering density difference between the injected gas and the remaining condensate gas in the formation. The vertical flow ratio and override degree are used to reflect the override law of injected dry gas. Combined with the actual data of Tarim gas condensate reservoir, the parameters of injected dry gas override are calculated and analysed. The results show that the radial pressure rises or falls rapidly and the pressure gradient varies greatly in the near wells. The radial pressure varies slowly and the pressure gradient changes little in the reservoir which is within a certain distance from the wells. In the near injection well, the injected dry gas mainly migrates along the radial direction, and the vertical migration is relatively not obvious. With the distance from the injection well, the vertical flow ratio and override degree of injected dry gas increases, and the vertical flow ratio reaches the maximum in the middle of the injection well and the production well.

Experimental study of the active control applied to the flow past a backward facing ramp

NASA Astrophysics Data System (ADS)

Hlevca, Dan; Gilliéron, Patrick; Grasso, Francesco

2018-03-01

An experimental study of open loop active flow control on a backward facing ramp is presented. The ramp has finite span and a slant angle of 25°. Wind tunnel experiments were performed both for the uncontrolled and the controlled cases where time periodic forcing by pulsed jets is considered. The control system exploits an electro-magnetic valve system to generate pulsed jets with an operating frequency and duty cycle ranging, respectively, between 50 and 250 Hz and between 25 and 60%. A parametric study was carried out for three different freestream velocities and varying the frequency of the pulsed jets and the duty cycle. The control strategy relies on the injection of periodic perturbations before separation at the edge of the slant, considering various combinations of frequencies and duty cycles while keeping constant the blowing time for every Reynolds number, so as to excite the flow with the same jet structure over different actuation cycle extents. The receptivity of the flow to periodic forcing was assessed by characterizing mean and unsteady flow properties, turbulence statistics and flow topology. The study focused on the impact of control on reattachement and showed that the flow locks with excitation frequencies typical of initial Kelvin-Helmholtz instabilities. However, the flow was found to respond to any injected unsteady perturbation locking to the forcing frequencies and the extent of the region where locking occurs was found to be of the order of a few slant heights. A relaxation process was observed and the flow was found to relax past the slant trailing edge toward frequencies close to the natural ones.

Slurry atomizer for a coal-feeder and dryer used to provide coal at gasifier pressure

DOEpatents

Loth, John L.; Smith, William C.; Friggens, Gary R.

1982-01-01

The present invention is directed to a coal-water slurry atomizer for use a high-pressure dryer employed in a pumping system utilized to feed coal into a pressurized coal gasifier. The slurry atomizer is provided with a venturi, constant area slurry injection conduit, and a plurality of tangentially disposed steam injection ports. Superheated steam is injected into the atomizer through these ports to provide a vortical flow of the steam, which, in turn, shears slurry emerging from the slurry injection conduit. The droplets of slurry are rapidly dispersed in the dryer through the venturi where the water is vaporized from the slurry by the steam prior to deleterious heating of the coal.

Containment of subsurface contaminants

DOEpatents

Corey, J.C.

1994-09-06

A barrier is disclosed for reducing the spread of a plume of subsurface contaminants. The apparatus includes a well system for injecting a fluid, such as air, just outside and below the periphery of the plume. The fluid is injected at a pressure sufficient to lower the hydraulic conductivity of the soil from the point of injection to the surface thus establishing a curtain-like barrier to groundwater movement. The barrier is established upgradient of the plume to divert groundwater away, or preferably completely around the plume to reduce the flow of groundwater into or out of the plume. The barrier enables the remediation of the confined contamination and then, when the injection of the fluid is halted, the barrier quickly dissipates. 5 figs.

Convective transport resistance in the vitreous humor

NASA Astrophysics Data System (ADS)

Penkova, Anita; Sadhal, Satwindar; Ratanakijsuntorn, Komsan; Moats, Rex; Tang, Yang; Hughes, Patrick; Robinson, Michael; Lee, Susan

2012-11-01

It has been established by MRI visualization experiments that the convection of nanoparticles and large molecules with high rate of water flow in the vitreous humor will experience resistance, depending on the respective permeabilities of the injected solute. A set of experiments conducted with Gd-DTPA (Magnevist, Bayer AG, Leverkusen, Germany) and 30 nm gadolinium-based particles (Gado CELLTrackTM, Biopal, Worcester, MA) as MRI contrast agents showed that the degree of convective transport in this Darcy-type porous medium varies between the two solutes. These experiments consisted of injecting a mixture of the two (a 30 μl solution of 2% Magnevist and 1% nanoparticles) at the middle of the vitreous of an ex vivo whole bovine eye and subjecting the vitreous to water flow rate of 100 μl/min. The water (0.9% saline solution) was injected at the top of the eye, and was allowed to drain through small slits cut at the bottom of the eyeball. After 50 minutes of pumping, MRI images showed that the water flow carried the Gd-DTPA farther than the nanoparticles, even though the two solutes, being mixed, were subjected to the same convective flow conditions. We find that the convected solute lags the water flow, depending on the solute permeability. The usual convection term needs to be adjusted to allow for the filtration effect on the larger particles in the form (1- σ) u . ∇ c with important implications for the modeling of such systems.

Spheromak plasma flow injection into a torus chamber and the HIST plasmas

NASA Astrophysics Data System (ADS)

Hatuzaki, Akinori

2005-10-01

The importance of plasma flow or two-fluid effect is recognized in understanding the relaxed states of high-beta torus plasmas, start-up and current drive by non-coaxial helicity injection, magnetic reconnection and plasma dynamo in fusion, laboratory and space plasmas. As a new approach to create a flowing two-fluid plasma equilibrium, we have tried to inject tangentially the plasma flow with spheromak-type magnetic configurations into a torus vacuum chamber with an external toroidal magnetic field (TF) coil. In the initial experiments, the RFP-like configuration with helical magnetic structures was realized in the torus vessel. The ion flow measurement with Mach probes showed that the ion flow keeps the same direction despite the reversal of the toroidal current and the axial electric field. The ion fluid comes to flow in the opposite direction to the electron fluid by the reversal of TF. This result suggests that not only electron but also ion flow contributes significantly on the reversed toroidal current. In this case, the ratio of ui to the electron flow velocity ue is estimated as ui/ue ˜ 1/2. We also will inject the spheromak flow into the HIST spherical torus plasmas to examine the possibilities to embedding the two-fluid effect in the ST plasmas.

Reservoir response to thermal and high-pressure well stimulation efforts at Raft River, Idaho

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plummer, Mitchell; Bradford, Jacob; Moore, Joseph

An injection stimulation test begun at the Raft River geothermal reservoir in June, 2013 has produced a wealth of data describing well and reservoir response via high-resolution temperature logging and distributed temperature sensing, seismic monitoring, periodic borehole televiewer logging, periodic stepped flow rate tests and tracer injections before and after stimulation efforts. One of the primary measures of response to the stimulation is the relationship between fluid pressure and flow rate, short-term during forced flow rate changes and the long-term change in injectivity. In this paper we examine that hydraulic response using standard pumping test analysis methods, largely because pressuremore » response to the stimulation was not detected, or measurable, in other wells. Analysis of stepped rate flow tests supports the inference from other data that a large fracture, with a radial extent of one to several meters, intersects the well in the target reservoir, suggests that the flow regime is radial to a distance of only several meters and demonstrates that the pressure build-up cone reaches an effective constant head at that distance. The well’s longer term hydraulic response demonstrated continually increasing injectivity but at a dramatically faster rate later from ~2 years out and continuing to the present. The net change in injectivity is significantly greater than observed in other longterm injectivity monitoring studies, with an approximately 150–fold increase occurring over ~2.5 years. While gradually increasing injectivity is a likely consequence of slow migration of a cooling front, and consequent dilation of fractures, the steady, ongoing, rate of increase is contrary to what would be expected in a radial or linear flow regime, where the cooling front would slow with time. As a result, occasional step-like changes in injectivity, immediately following high-flow rate tests suggest that hydro shearing during high-pressure testing altered the near-well permeability structure.« less

On the existence of solutions of an equation arising in the theory of laminar flow in a uniformly porous channel with injection

NASA Technical Reports Server (NTRS)

Shih, K. G.

1986-01-01

The existence of concave solutions of Berman's equation which describes the laminar flow in channels with injection through porous walls is established. It was found that the (unique) concave solutions exist for all injection Reynolds number R < 0.

Dysprosium-sensitized chemiluminescence system for the determination of enoxacin in pharmaceutical preparations and biological fluids with flow-injection sampling.

PubMed

Sun, Han-wen; Wu, Yuan-yuan; Li, Li-qing

2009-03-01

A novel trivalence dysprosium(Dy(3+))-sensitized chemiluminescence method was developed for the first time for the determination of enoxacin (ENX) using flow-injection sampling based on the chemiluminescence (CL) associated with the reaction of the Dy(3+)-cerium(Ce(IV))-S(2)O(3) (2-)-ENX system and the Dy(3+)-MnO(4) (-) S(2)O(3) (2-)-ENX system. The analytical conditions for CL emission were investigated and optimized. The relationship between the CL intensity of ENX and its concentration has good linearity, with a correlation coefficient of 0.9984-0.9994. The limit of detection (LOD, 3sigma) was 0.20 ng/mL for the Dy(3+)-ENX-S(2)O(3)(2-)-Ce(IV)-H(2)SO(4) system and 0.22 ng/mL for the Dy(3+)-ENX-S(2)O(3)(2-)-MnO(4) (-)-HNO(3) system. The relative standard deviation (RSD, n = 11) was 1.8% for 11 determinations of 60 ng/mL ENX. The proposed method was applied to the analysis of ENX in injections, serum and urine samples with a recovery of 98%-105%. A possible mechanism for this sensitized CL reaction is discussed by comparing the CL spectra with the fluorescence emission spectra. The proposed method represents a wide linear range, high sensitivity and accuracy, and can be used for the routine determination of ENX in pharmaceutical preparations and biological fluids. Copyright 2009 John Wiley & Sons, Ltd.

Generation of human-to-pig chimerism to induce tolerance through transcutaneous in utero injection of cord blood-derived mononuclear cells or human bone marrow mesenchymals cells in a preclinical program of liver xenotransplantation: preliminary results.

PubMed

Abellaneda, J M; Ramis, G; Martínez-Alarcón, L; Majado, M J; Quereda, J J; Herrero-Medrano, J M; Mendonça, L; García-Nicolás, O; Reus, M; Insausti, C; Ríos, A; López-Navas, A; González, M R; Pallarés, F J; Munoz, A; Ramírez, P; Parrilla, P

2012-01-01

Using a percutaneous ecoguided injection system to obtain chimeric piglets through a less invasive and traumatic technique than previously reported. The two types of human cells included umbilical cord blood mononuclear elements and mesenchymal stem cells cultured from bone marrow. Four sows at gestational day 50 were anesthetized. A needle was inserted through the skin and uterine wall to reach the peritoneal cavity of the fetuses under continuous ultrasound guidance. Fourteen piglets were injected with various cell concentrations. All sows carried pregnancies to term yielding 69 piglets, among which 67 were alive and two mummified. Two piglets died during the first 48 hours of life. Chimerism was detected using flow cytometry and by quantitative polymerase chain reaction (q-PCR) to detect Alu gene in blood or tissues samples. The analysis detected blood chimerism in 13 piglets (21%) by flow cytometry and the presence of the human Alu gene in 33 (51%) by q-PCR. The results suggest cell trafficking between littermates after in utero injection. Transcutaneous echo-guided injection succeeded to produce chimeric piglets without disadvantages to the sow or the fetuses and avoiding abortions or fetal death. Copyright © 2012 Elsevier Inc. All rights reserved.

Modification of the continuous flow diffusion chamber for use in zero-gravity. [atmospheric cloud physics lab

NASA Technical Reports Server (NTRS)

Keyser, G.

1978-01-01

The design philosophy and performance characteristics of the continuous flow diffusion chamber developed for use in ground-based simulation of some of the experiments planned for the atmospheric cloud physics laboratory during the first Spacelab flight are discussed. Topics covered include principle of operation, thermal control, temperature measurement, tem-powered heat exchangers, wettable metal surfaces, sample injection system, and control electronics.

Determination of mercury in agroindustrial samples by flow-injection cold vapor atomic absorption spectrometry using ion exchange and reductive elution.

PubMed

Gomes Neto, J A; Zara, L F; Rocha, J C; Santos, A; Dakuzaku, C S; Nóbrega, J A

2000-03-06

A flow-injection system with a Chelite-S(R) cationic resin packed minicolumn is proposed for the determination of trace levels of mercury in agroindustrial samples by cold vapor atomic absorption spectrometry. Improved sensitivity and selectivity are attained since mercuric ions are on-line concentrated whereas other potential interferents are discarded. With on-line reductive elution procedure, concentrated hydrochloric acid could be replaced by 10% w/v SnCl(2), in 6 M HCl as eluent. The reversed-intermittent stream either carries the atomic mercury to the flow cell in the forward direction or removes the residue from reactor/gas-liquid separator to a discarding flask in the opposite direction. Concentration and volume of reagent, acidity, flow rates, commutation times and potential interfering species were investigated. For 120 s preconcentration time, the proposed system handles about 25 samples h(-1) (50.0-500 ng l(-1)), consuming about 10 ml sample and 5 mg SnCl(2) per determination. The detection limit is 0.8 ng l(-1) and the relative standard deviation (RSD) (n=12) of a 76.7 ng l(-1) sample is about 5%. Results are in agreement with certified value of standard materials at 95% confidence level and good recoveries (97-128%) of spiked samples were found.

Simulated effects of ground-water withdrawals and artificial recharge on discharge to streams, springs, and riparian vegetation in the Sierra Vista Subwatershed of the Upper San Pedro Basin, southeastern Arizona

USGS Publications Warehouse

Leake, Stanley A.; Pool, Donald R.; Leenhouts, James M.

2008-01-01

In the context of ground-water resources, “capture” or “streamflow depletion” refers to withdrawal-induced changes in inflow to or outflow from an aquifer. These concepts are helpful in understanding the effects of long-term development of ground-water resources. For the Upper San Pedro Basin in Arizona, USA and Sonora, Mexico, a recently developed ground-water flow model is available to help quantify capture of water from the river and riparian system. A common method of analysis is to compute curves of capture and aquifer-storage change for a range of time at select points of interest. This study, however, presents results of a method to show spatial distributions of total change in inflow and outflow from withdrawal or injection for select times of interest. The mapped areal distributions show the effect of a single well in terms of the ratio of the change in boundary flow rate to rate of withdrawal or injection by the well. To the extent that the system responds linearly to ground-water withdrawal or injection, fractional responses in the mapped distributions can be used to quantify response for any withdrawal or injection rate. Capture distributions calculated using the Upper San Pedro model include response to (1) withdrawal in the lower basin-fill aquifer for times of 10 and 50 years following the initiation of pumping from predevelopment conditions and (2) artificial recharge to the water table in the area underlain by the lower basin-fill aquifer after 10 and 50 years. The mapped distributions show that response to withdrawals and injections is greatest near the river/riparian system. Presence of clay layers in the vertical interval between withdrawal locations and the river/riparian system, however, can delay the response.

Bubble Formation from Wall Orifice in Liquid Cross-Flow Under Low Gravity

NASA Technical Reports Server (NTRS)

Nahra, Henry K.; Kamotani, Y.

2000-01-01

Two-phase flows present a wide variety of applications for spacecraft thermal control systems design. Bubble formation and detachment is an integral part of the two phase flow science. The objective of the present work is to experimentally investigate the effects of liquid cross-flow velocity, gas flow rate, and orifice diameter on bubble formation in a wall-bubble injection configuration. Data were taken mainly under reduced gravity conditions but some data were taken in normal gravity for comparison. The reduced gravity experiment was conducted aboard the NASA DC-9 Reduced Gravity Aircraft. The results show that the process of bubble formation and detachment depends on gravity, the orifice diameter, the gas flow rate, and the liquid cross-flow velocity. The data are analyzed based on a force balance, and two different detachment mechanisms are identified. When the gas momentum is large, the bubble detaches from the injection orifice as the gas momentum overcomes the attaching effects of liquid drag and inertia. The surface tension force is much reduced because a large part of the bubble pinning edge at the orifice is lost as the bubble axis is tilted by the liquid flow. When the gas momentum is small, the force balance in the liquid flow direction is important, and the bubble detaches when the bubble axis inclination exceeds a certain angle.

Mathematical Investigation of Fluid Flow, Mass Transfer, and Slag-steel Interfacial Behavior in Gas-stirred Ladles

NASA Astrophysics Data System (ADS)

Cao, Qing; Nastac, Laurentiu

2018-06-01

In this study, the Euler-Euler and Euler-Lagrange modeling approaches were applied to simulate the multiphase flow in the water model and gas-stirred ladle systems. Detailed comparisons of the computational and experimental results were performed to establish which approach is more accurate for predicting the gas-liquid multiphase flow phenomena. It was demonstrated that the Euler-Lagrange approach is more accurate than the Euler-Euler approach. The Euler-Lagrange approach was applied to study the effects of the free surface setup, injected bubble size, gas flow rate, and slag layer thickness on the slag-steel interaction and mass transfer behavior. Detailed discussions on the flat/non-flat free surface assumption were provided. Significant inaccuracies in the prediction of the surface fluid flow characteristics were found when the flat free surface was assumed. The variations in the main controlling parameters (bubble size, gas flow rate, and slag layer thickness) and their potential impact on the multiphase fluid flow and mass transfer characteristics (turbulent intensity, mass transfer rate, slag-steel interfacial area, flow patterns, etc.,) in gas-stirred ladles were quantitatively determined to ensure the proper increase in the ladle refining efficiency. It was revealed that by injecting finer bubbles as well as by properly increasing the gas flow rate and the slag layer thickness, the ladle refining efficiency can be enhanced significantly.

MODFLOW 2.0: A program for predicting moderator flow patterns

NASA Astrophysics Data System (ADS)

Peterson, P. F.; Paik, I. K.

1991-07-01

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in the operation of the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides transient moderator flow pattern information with stratification effects, and tracks the location of ink plumes in the reactor. The code, written in Fortran, is compiled for Macintosh II computers, and includes subroutines for interactive control and graphical output. Removing the graphics capabilities, the code can also be compiled on other computers. With graphics, in addition to the capability to perform safety related computations, MODFLOW also provides an easy tool for becoming familiar with flow distributions in SRS reactors.

National Combustion Code Validated Against Lean Direct Injection Flow Field Data

NASA Technical Reports Server (NTRS)

Iannetti, Anthony C.

2003-01-01

Most combustion processes have, in some way or another, a recirculating flow field. This recirculation stabilizes the reaction zone, or flame, but an unnecessarily large recirculation zone can result in high nitrogen oxide (NOx) values for combustion systems. The size of this recirculation zone is crucial to the performance of state-of-the-art, low-emissions hardware. If this is a large-scale combustion process, the flow field will probably be turbulent and, therefore, three-dimensional. This research dealt primarily with flow fields resulting from lean direct injection (LDI) concepts, as described in Research & Technology 2001. LDI is a concept that depends heavily on the design of the swirler. The LDI concept has the potential to reduce NOx values from 50 to 70 percent of current values, with good flame stability characteristics. It is cost effective and (hopefully) beneficial to do most of the design work for an LDI swirler using computer-aided design (CAD) and computer-aided engineering (CAE) tools. Computational fluid dynamics (CFD) codes are CAE tools that can calculate three-dimensional flows in complex geometries. However, CFD codes are only beginning to correctly calculate the flow fields for complex devices, and the related combustion models usually remove a large portion of the flow physics.

Optimization of Tangential Mass Injection for Minimizing Flow Separation in a Scramjet Inlet

DTIC Science & Technology

1991-12-01

34 Aerospace EnQineering, Vol. 11. No. 8, August 1991, p.23. 26. Heppenheimer , Thomas A . Lecture notes from Hypersonic Technologies seminar. University...AFIT/GAE/ENY,/9 lD-2 ( /~ AD-A243 868 "DTIC OPTIMIZATION OF TANGENTIAL MASS INJECTION FOR MINIMIZING FLOW SEPARATION IN A SC.R-.MJET INLET THESIS...OF TANGENTIAL MASS INJECTION FOR MINIMIZING FLOW SEPARATION IN A SCRAMJET INLEr THESIS Presented to the Faculty of the School of E.ngineering of the

Pulsed Turbulent Diffusion Flames in a Coflow

NASA Astrophysics Data System (ADS)

Usowicz, James E.; Hermanson, James C.; Johari, Hamid

2000-11-01

Fully modulated diffusion flames were studied experimentally in a co-flow combustor using unheated ethylene fuel at atmospheric pressure. A fast solenoid valve was used to fully modulate (completely shut-off) the fuel flow. The fuel was released from a 2 mm diameter nozzle with injection times ranging from 2 to 750 ms. The jet exit Reynolds number was 2000 to 10,000 with a co-flow air velocity of up to 0.02 times the jet exit velocity. Establishing the effects of co-flow for the small nozzle and short injection times is required for future tests of pulsed flames under microgravity conditions. The very short injection times resulted in compact, burning puffs. The compact puffs had a mean flame length as little as 20flame for the same Reynolds number. As the injection time and fuel volume increased, elongated flames resembling starting jets resulted with a flame length comparable to that of a steady flame. For short injection times, the addition of an air co-flow resulted in an increase in flame length of nearly 50flames with longer injection times was correspondingly smaller. The effects of interaction of successive pulses on the flame length were most pronounced for the compact puffs. The emissions of unburned hydrocarbon and NOx from the pulsed flames were examined.

Toward the optical tongue: flow-through sensing of tannin-protein interactions based on FTIR spectroscopy.

PubMed

Edelmann, Andrea; Lendl, Bernhard

2002-12-11

The interaction of polyphenols (tannins) with proline-rich proteins (gelatin) has been studied using an automated flow injection system with Fourier transform infrared spectroscopic detection to gain insight into chemical aspects related to astringency. In the perception of astringency, a major taste property in red wines and other beverages such as beer, tea, or fruit juices, an interaction between proline-rich salivary proteins and tannins present in the sample takes place. To study this interaction, agarose beads carrying gelatin (a proline-rich protein) were placed in the IR flow cell in such a way that the beads were probed by the IR beam. Using an automated flow system, we injected samples in a carrier stream and flushed over the proteins in a highly reproducible manner. Simultaneously, any retardation due to tannin-protein interactions taking place inside the flow cell was monitored by infrared spectroscopy. Tannins of different sources (grapes, wooden barrels, formulations used in wine making) were investigated, and their flow-through behavior was characterized. Significant differences in their affinity toward gelatin could be observed. Furthermore, because of small but characteristic differences in the IR spectrum, it is possible to distinguish condensed from hydrolyzable tannins. Nonastringent substances such as alcohols, sugars, and acids did not show retention on gelatin. The selectivity of the flow-through sensor was also demonstrated on the example of red and white wine. In contrast to white wine, where no interaction could be observed, in red wine a major interaction of the red wine tannins was found.

Secondary air injection system and method

DOEpatents

Wu, Ko-Jen; Walter, Darrell J.

2014-08-19

According to one embodiment of the invention, a secondary air injection system includes a first conduit in fluid communication with at least one first exhaust passage of the internal combustion engine and a second conduit in fluid communication with at least one second exhaust passage of the internal combustion engine, wherein the at least one first and second exhaust passages are in fluid communication with a turbocharger. The system also includes an air supply in fluid communication with the first and second conduits and a flow control device that controls fluid communication between the air supply and the first conduit and the second conduit and thereby controls fluid communication to the first and second exhaust passages of the internal combustion engine.

RAPID REMOVAL OF A GROUNDWATER CONTAMINANT PLUME.

USGS Publications Warehouse

Lefkoff, L. Jeff; Gorelick, Steven M.; ,

1985-01-01

A groundwater management model is used to design an aquifer restoration system that removes a contaminant plume from a hypothetical aquifer in four years. The design model utilizes groundwater flow simulation and mathematical optimization. Optimal pumping and injection strategies achieve rapid restoration for a minimum total pumping cost. Rapid restoration is accomplished by maintaining specified groundwater velocities around the plume perimeter towards a group of pumping wells located near the plume center. The model does not account for hydrodynamic dispersion. Results show that pumping costs are particularly sensitive to injection capacity. An 8 percent decrease in the maximum allowable injection rate may lead to a 29 percent increase in total pumping costs.

Pressure and Flow Rate Changes During Contrast Injections in Cerebral Angiography: Correlation to Reflux Length.

PubMed

Kovarovic, Brandon; Woo, Henry H; Fiorella, David; Lieber, Baruch B; Sadasivan, Chander

2018-03-01

Cerebral angiography involves the antegrade injection of contrast media through a catheter into the vasculature to visualize the region of interest under X-ray imaging. Depending on the injection and blood flow parameters, the bolus of contrast can propagate in the upstream direction and proximal to the catheter tip, at which point contrast is said to have refluxed. In this in vitro study, we investigate the relationship of fundamental hemodynamic variables to this phenomenon. Contrast injections were carried out under steady and pulsatile flow using various vessel diameters, catheter sizes, working fluid flow rates, and injection rates. The distance from the catheter tip to the proximal edge of the contrast bolus, called reflux length, was measured on the angiograms; the relation of this reflux length to different hemodynamic parameters was evaluated. Results show that contrast reflux occurs when the pressure distal to the catheter tip increases to be greater than the pressure proximal to the catheter tip. The ratio of this pressure difference to the baseline flow rate, called reflux resistance here, was linearly correlated to the normalized reflux length (reflux length/vessel diameter). Further, the ratio of blood flow to contrast fluid momentums, called the Craya-Curtet number, was correlated to the normalized reflux length via a sigmoid function. A sigmoid function was also found to be representative of the relationship between the ratio of the Reynolds numbers of blood flow to contrast and the normalized reflux length. As described by previous reports, catheter based contrast injections cause substantial increases in local flow and pressure. Contrast reflux should generally be avoided during standard antegrade angiography. Our study shows two specific correlations between contrast reflux length and baseline and intra-injection parameters that have not been published previously. Further studies need to be conducted to fully characterize the phenomena and to extract reliable indicators of clinical utility. Parameters relevant to cerebral angiography are studied here, but the essential principles are applicable to all angiographic procedures involving antegrade catheter injections.

Using biplanar fluoroscopy to guide radiopaque vascular injections: a new method for vascular imaging.

PubMed

O'Brien, Haley D; Williams, Susan H

2014-01-01

Studying vascular anatomy, especially in the context of relationships with hard tissues, is of great interest to biologists. Vascular studies have provided significant insight into physiology, function, phylogenetic relationships, and evolutionary patterns. Injection of resin or latex into the vascular system has been a standard technique for decades. There has been a recent surge in popularity of more modern methods, especially radiopaque latex vascular injection followed by CT scanning and digital "dissection." This technique best displays both blood vessels and bone, and allows injections to be performed on cadaveric specimens. Vascular injection is risky, however, because it is not a standardizable technique, as each specimen is variable with regard to injection pressure and timing. Moreover, it is not possible to view the perfusion of injection medium throughout the vascular system of interest. Both data and rare specimens can therefore be lost due to poor or excessive perfusion. Here, we use biplanar video fluoroscopy as a technique to guide craniovascular radiopaque latex injection. Cadaveric domestic pigs (Sus scrofa domestica) and white-tailed deer (Odocoileus virginianus) were injected with radiopaque latex under guidance of fluoroscopy. This method was found to enable adjustments, in real-time, to the rate, location, and pressure at which latex is injected in order to avoid data and specimen loss. In addition to visualizing the injection process, this technique can be used to determine flow patterns, and has facilitated the development of consistent markers for complete perfusion.

Process and apparatus for producing ultrafine explosive particles

DOEpatents

McGowan, Michael J.

1992-10-20

A method and an improved eductor apparatus for producing ultrafine explosive particles is disclosed. The explosive particles, which when incorporated into a binder system, have the ability to propagate in thin sheets, and have very low impact sensitivity and very high propagation sensitivity. A stream of a solution of the explosive dissolved in a solvent is thoroughly mixed with a stream of an inert nonsolvent by obtaining nonlaminar flow of the streams by applying pressure against the flow of the nonsolvent stream, to thereby diverge the stream as it contacts the explosive solution, and violently agitating the combined stream to rapidly precipitate the explosive particles from the solution in the form of generally spheroidal, ultrafine particles. The two streams are injected coaxially through continuous, concentric orifices of a nozzle into a mixing chamber. Preferably, the nonsolvent stream is injected centrally of the explosive solution stream. The explosive solution stream is injected downstream of and surrounds the nonsolvent solution stream for a substantial distance prior to being ejected into the mixing chamber.

Sensitive determination of 2-methoxyestradiol in pharmaceutical preparations and serum samples using flow injection chemiluminescence.

PubMed

Yao, Hanchun; Zhang, Min; Zeng, Wenyuan; Zeng, Xiaoying; Zhang, Zhenzhong

2014-05-01

A rapid and sensitive flow injection chemiluminescence (FI-CL) method is described for the determination of 2-methoxyestradiol (2ME) based on enhancement of the CL intensity from a potassium ferricyanide-calcein system in sodium hydroxide medium. The optimum conditions for the CL emission were investigated. Under optimized conditions, a linear calibration graph was obtained over the range 1.0 × 10(-8) to 1.0 × 10(-6) mol/L (r = 0.998) 2ME with a detection limit (3σ) of 5.4 × 10(-9) mol/L. The relative standard deviation (RSD) for 5.0 × 10(-7) mol/L 2ME was 1.7%. As a preliminary application, the proposed method was successfully applied to the determination of 2ME in injection solutions and serum samples. The possible CL mechanism was also proposed. Copyright © 2013 John Wiley & Sons, Ltd.

Active chimney effect using heated porous layers: optimum heat transfer

NASA Astrophysics Data System (ADS)

Mehiris, Abdelhak; Ameziani, Djamel-Edine; Rahli, Omar; Bouhadef, Khadija; Bennacer, Rachid

2017-05-01

The purpose of the present work is to treat numerically the problem of the steady mixed convection that occurs in a vertical cylinder, opened at both ends and filled with a succession of three fluid saturated porous elements, namely a partially porous duct. The flow conditions fit with the classical Darcy-Brinkman model allowing analysing the flow structure on the overall domain. The induced heat transfer, in terms of local and average Nusselt numbers, is discussed for various controlling parameters as the porous medium permeability, Rayleigh and Reynolds numbers. The efficiency of the considered system is improved by the injection/suction on the porous matrices frontier. The undertaken numerical exploration particularly highlighted two possible types of flows, with and without fluid recirculation, which principally depend on the mixed convection regime. Thus, it is especially shown that recirculation zones appear in some domain areas under specific conditions, obvious by a negative central velocity and a prevalence of the natural convection effects, i.e., turnoff flow swirls. These latter are more accentuated in the areas close to the porous obstacles and for weak permeability. Furthermore, when fluid injection or suction is considered, the heat transfer increases under suction and reduces under injection. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

FLIT: Flowing LIquid metal Torus

NASA Astrophysics Data System (ADS)

Kolemen, Egemen; Majeski, Richard; Maingi, Rajesh; Hvasta, Michael

2017-10-01

The design and construction of FLIT, Flowing LIquid Torus, at PPPL is presented. FLIT focuses on a liquid metal divertor system suitable for implementation and testing in present-day fusion systems, such as NSTX-U. It is designed as a proof-of-concept fast-flowing liquid metal divertor that can handle heat flux of 10 MW/m2 without an additional cooling system. The 72 cm wide by 107 cm tall torus system consisting of 12 rectangular coils that give 1 Tesla magnetic field in the center and it can operate for greater than 10 seconds at this field. Initially, 30 gallons Galinstan (Ga-In-Sn) will be recirculated using 6 jxB pumps and flow velocities of up to 10 m/s will be achieved on the fully annular divertor plate. FLIT is designed as a flexible machine that will allow experimental testing of various liquid metal injection techniques, study of flow instabilities, and their control in order to prove the feasibility of liquid metal divertor concept for fusion reactors. FLIT: Flowing LIquid metal Torus. This work is supported by the US DOE Contract No. DE-AC02-09CH11466.

Economic Implementation and Optimization of Secondary Oil Recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cary D. Brock

The St Mary West Barker Sand Unit (SMWBSU or Unit) located in Lafayette County, Arkansas was unitized for secondary recovery operations in 2002 followed by installation of a pilot injection system in the fall of 2003. A second downdip water injection well was added to the pilot project in 2005 and 450,000 barrels of saltwater has been injected into the reservoir sand to date. Daily injection rates have been improved over initial volumes by hydraulic fracture stimulation of the reservoir sand in the injection wells. Modifications to the injection facilities are currently being designed to increase water injection rates formore » the pilot flood. A fracture treatment on one of the production wells resulted in a seven-fold increase of oil production. Recent water production and increased oil production in a producer closest to the pilot project indicates possible response to the water injection. The reservoir and wellbore injection performance data obtained during the pilot project will be important to the secondary recovery optimization study for which the DOE grant was awarded. The reservoir characterization portion of the modeling and simulation study is in progress by Strand Energy project staff under the guidance of University of Houston Department of Geosciences professor Dr. Janok Bhattacharya and University of Texas at Austin Department of Petroleum and Geosystems Engineering professor Dr. Larry W. Lake. A geologic and petrophysical model of the reservoir is being constructed from geophysical data acquired from core, well log and production performance histories. Possible use of an outcrop analog to aid in three dimensional, geostatistical distribution of the flow unit model developed from the wellbore data will be investigated. The reservoir model will be used for full-field history matching and subsequent fluid flow simulation based on various injection schemes including patterned water flooding, addition of alkaline surfactant-polymer (ASP) to the injected water, and high pressure air injection (HPAI) for in-situ low temperature oxidization (LTO) will be studied for optimization of the secondary recovery process.« less

Liquid sprays and flow studies in the direct-injection diesel engine under motored conditions

NASA Technical Reports Server (NTRS)

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.

Power System Transient Stability Improvement by the Interline Power Flow Controller (IPFC)

NASA Astrophysics Data System (ADS)

Zhang, Jun; Yokoyama, Akihiko

This paper presents a study on the power system transient stability improvement by means of interline power flow controller (IPFC). The power injection model of IPFC in transient analysis is proposed and can be easily incorporated into existing power systems. Based on the energy function analysis, the operation of IPFC should guarantee that the time derivative of the global energy of the system is not greater than zero in order to damp the electromechanical oscillations. Accordingly, control laws of IPFC are proposed for its application to the single-machine infinite-bus (SMIB) system and the multimachine systems, respectively. Numerical simulations on the corresponding model power systems are presented to demonstrate their effectiveness in improving power system transient stability.

Effect of acute moderate exercise on induced inflammation and arterial function in older adults.

PubMed

Ranadive, Sushant Mohan; Kappus, Rebecca Marie; Cook, Marc D; Yan, Huimin; Lane, Abbi Danielle; Woods, Jeffrey A; Wilund, Kenneth R; Iwamoto, Gary; Vanar, Vishwas; Tandon, Rudhir; Fernhall, Bo

2014-04-01

Acute inflammation reduces flow-mediated vasodilatation and increases arterial stiffness in young healthy individuals. However, this response has not been studied in older adults. The aim of this study, therefore, was to evaluate the effect of acute induced systemic inflammation on endothelial function and wave reflection in older adults. Furthermore, an acute bout of moderate-intensity aerobic exercise can be anti-inflammatory. Taken together, we tested the hypothesis that acute moderate-intensity endurance exercise, immediately preceding induced inflammation, would be protective against the negative effects of acute systemic inflammation on vascular function. Fifty-nine healthy volunteers between 55 and 75 years of age were randomized to an exercise or a control group. Both groups received a vaccine (induced inflammation) and sham (saline) injection in a counterbalanced crossover design. Inflammatory markers, endothelial function (flow-mediated vasodilatation) and measures of wave reflection and arterial stiffness were evaluated at baseline and at 24 and 48 h after injections. There were no significant differences in endothelial function and arterial stiffness between the exercise and control group after induced inflammation. The groups were then analysed together, and we found significant differences in the inflammatory markers 24 and 48 h after induction of acute inflammation compared with sham injection. However, flow-mediated vasodilatation, augmentation index normalized for heart rate (AIx75) and β-stiffness did not change significantly. Our results suggest that acute inflammation induced by influenza vaccination did not affect endothelial function in older adults.

Direct-injection chemiluminescence detector. Properties and potential applications in flow analysis.

PubMed

Koronkiewicz, Stanislawa; Kalinowski, Slawomir

2015-02-01

We present a novel chemiluminescence detector, with a cone-shaped detection chamber where the analytical reaction takes place. The sample and appropriate reagents are injected directly into the chamber in countercurrent using solenoid-operated pulse micro-pumps. The proposed detector allows for fast measurement of the chemiluminescence signal in stop-flow conditions from the moment of reagents mixing. To evaluate potential applications of the detector the Fenton-like reaction with a luminol-H2O2 system and several transition metal ions (Co(2+), Cu(2+), Cr(3+), Fe(3+)) as a catalyst were investigated. The results demonstrate suitability of the proposed detector for quantitative analysis and for investigations of reaction kinetics, particularly rapid reactions. A multi-pumping flow system was designed and optimized. The developed methodology demonstrated that the shape of the analytical signals strongly depends on the type and concentration of the metal ions. The application of the detector in quantitative analysis was assessed for determination of Fe(III). The direct-injection chemiluminescence detector allows for a sensitive and repeatable (R.S.D. 2%) determination. The intensity of chemiluminescence increased linearly in the range from about 0.5 to 10 mg L(-1) Fe(III) with the detection limit of 0.025 mg L(-1). The time of analysis depended mainly on reaction kinetics. It is possible to achieve the high sampling rate of 144 samples per hour. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantifying regional cerebral blood flow by N-isopropyl-P-[I-123]iodoamphetamine (IMP) using a ring type single-photon emission computed tomography system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahashi, N.; Odano, I.; Ohkubo, M.

1994-05-01

We developed a more accurate quantitative measurement of regional cerebral blood flow (rCBF) with the microsphere model using N-isopropyl-p-[I-123] iodoamphetamine (IMP) and a ring type single photon emission computed tomography (SPECT) system. SPECT studies were performed in 17 patients with brain diseases. A dose of 222 MBq (6 mCi) of [I-123]IMP was injected i.v., at the same time a 5 min period of arterial blood withdrawal was begun. SPECT data were acquired from 25 min to 60 min after tracer injection. For obtaining the brain activity concentration at 5 min after IMP injection, total brain counts collections and one minutemore » period short time SPECT studies were performed at 5, 20, and 60 min. Measurement of the values of rCBF was calculated using short time SPECT images at 5 min (rCBF), static SPECT images corrected with total cerebral counts (rCBF{sub Ct}.) and those corrected with reconstructed counts on short time SPECT images (rCBF{sub Cb}). There was a good relationship (r=0.69) between rCBF and rCBF{sub Ct}, however, rCBF{sub Ct} tends to be underestimated in high flow areas and overestimated in low flow areas. There was better relationship between rCBF and rCBF{sub Cb}(r=0.92). The overestimation and underestimation shown in rCBF{sub Ct} was considered to be due to the correction of reconstructed counts using a total cerebral time activity curve, because of the kinetic behavior of [I-123]IMP was different in each region. We concluded that more accurate rCBF values could be obtained using the regional time activity curves.« less

Numerical simulations of an impinging liquid spray in a cross-flow

NASA Astrophysics Data System (ADS)

Gomatam, Sreekar; Vengadesan, S.; Chakravarthy, S. R.

2017-11-01

The characteristics of a liquid spray in a uniform cross-flow field are numerically simulated in this study. A hollow cone liquid spray is injected perpendicular to the air stream flowing through a rectangular duct under room temperature and pressure. An Eulerian-Lagrangian framework is adopted to simulate the spray in cross-flow phenomenon. The cross-flow velocity is varied from 6-12 m/s while the liquid injection pressure is varied from 0.3-0.6 MPa. The liquid droplets from the injected spray undergo breakup and/or coalescence further in the cross-flow. Moreover, the spray injected into the cross-flow impinges on the opposite wall resulting in the formation of a liquid film. This liquid film disintegrates further into discrete droplets because of the impingement of the droplets from the spray and the shear from the cross-flow. The overall distribution of the droplets in the cross-flow for varying conditions is studied in detail. The evolution of the liquid film with space and time for varying conditions is also investigated. Suitable sub-models are used to numerically model the droplet break-up, coalescence, liquid film formation and disintegration, splashing of the droplets on the film and subsequent formation of daughter droplets. Department of Applied Mechanics, Indian Inst of Tech-Madras.

A new Doppler-echo method to quantify regurgitant volume.

PubMed

Wang, S S; Rubenstein, J J; Goldman, M; Sidd, J J

1992-01-01

An in vitro technique using color flow imaging and continuous wave Doppler was developed to measure the initial regurgitant flow jet diameter and velocity integral to yield the parameters for a volume calculation. Jets were produced by volume-controlled injection through tubes of various diameters (1.3, 1.9, 2.8, and 3.5 mm) to deliver volumes from 1 to 7 ml over 100 to 300 msec at pressures from 40 to 200 mm Hg. One hundred forty-five samples were obtained. Flow jet diameter consistently overestimated tube diameter by 2 mm when injected volume was 1.5 to 7 ml and by 1.5 mm when injected volume was less than 1.5 ml. This offset was stable with various transducers (2.5, 3.5, 5.0 MHz) at normal gain setting (just under noise). Therefore, corrected flow jet diameter (FJD) = FJD - 2 mm, and Doppler volume = corrected flow jet area x velocity integral. A range of injectates from 1.1 to 7 ml generated Doppler volume of 1.0 to 8.2 ml. The relation between Doppler volume (DV) and injected volume (IV) was DV = 1.079 IV - 0.22, r2 = 0.945, p less than 0.01. This relation was not altered by tube diameter. Thus a method combining color flow imaging and continuous wave Doppler provides a reliable and accurate measure of in vitro flow volume.

An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.

PubMed

Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G

2016-08-15

A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Detection of Total Phenol in Green and Black Teas by Flow Injection System and Unmodified Screen Printed Electrode

PubMed Central

de Mattos, Ivanildo Luiz; Zagal, José Heraclito

2010-01-01

A flow injection system using an unmodified gold screen-printed electrode was employed for total phenol determination in black and green teas. In order to avoid passivation of the electrode surface due to the redox reaction, preoxidation of the sample was realized by hexacyanoferrate(III) followed by addition of an EDTA solution. The complex formed in the presence of EDTA minimizes or avoids polymerization of the oxidized phenols. The previously filtered tea sample and hexacyanoferrate(III) reagent were introduced simultaneously into two-carrier streams producing two reproducible zones. At confluence point, the pre-oxidation of the phenolic compounds occurs while this zone flows through the coiled reactor and receives the EDTA solution before phenol detection. The consumption of ferricyanide was monitorized at 360 mV versus Ag/AgCl and reflected the total amount of phenolic compounds present in the sample. Results were reported as gallic acid equivalents (GAEs). The proposed system is robust, versatile, environmentally-friendly (since the reactive is used only in the presence of the sample), and allows the analysis of about 35–40 samples per hour with detection limit = 1 mg/L without the necessity for surface cleaning after each measurement. Precise results are in agreement with those obtained by the Folin-Ciocalteu method. PMID:21461407

Fracture Propagation, Fluid Flow, and Geomechanics of Water-Based Hydraulic Fracturing in Shale Gas Systems and Electromagnetic Geophysical Monitoring of Fluid Migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jihoon; Um, Evan; Moridis, George

2014-12-01

We investigate fracture propagation induced by hydraulic fracturing with water injection, using numerical simulation. For rigorous, full 3D modeling, we employ a numerical method that can model failure resulting from tensile and shear stresses, dynamic nonlinear permeability, leak-off in all directions, and thermo-poro-mechanical effects with the double porosity approach. Our numerical results indicate that fracture propagation is not the same as propagation of the water front, because fracturing is governed by geomechanics, whereas water saturation is determined by fluid flow. At early times, the water saturation front is almost identical to the fracture tip, suggesting that the fracture is mostlymore » filled with injected water. However, at late times, advance of the water front is retarded compared to fracture propagation, yielding a significant gap between the water front and the fracture top, which is filled with reservoir gas. We also find considerable leak-off of water to the reservoir. The inconsistency between the fracture volume and the volume of injected water cannot properly calculate the fracture length, when it is estimated based on the simple assumption that the fracture is fully saturated with injected water. As an example of flow-geomechanical responses, we identify pressure fluctuation under constant water injection, because hydraulic fracturing is itself a set of many failure processes, in which pressure consistently drops when failure occurs, but fluctuation decreases as the fracture length grows. We also study application of electromagnetic (EM) geophysical methods, because these methods are highly sensitive to changes in porosity and pore-fluid properties due to water injection into gas reservoirs. Employing a 3D finite-element EM geophysical simulator, we evaluate the sensitivity of the crosswell EM method for monitoring fluid movements in shaly reservoirs. For this sensitivity evaluation, reservoir models are generated through the coupled flow-geomechanical simulator and are transformed via a rock-physics model into electrical conductivity models. It is shown that anomalous conductivity distribution in the resulting models is closely related to injected water saturation, but not closely related to newly created unsaturated fractures. Our numerical modeling experiments demonstrate that the crosswell EM method can be highly sensitive to conductivity changes that directly indicate the migration pathways of the injected fluid. Accordingly, the EM method can serve as an effective monitoring tool for distribution of injected fluids (i.e., migration pathways) during hydraulic fracturing operations« less

A Physical Model Study of Two-Phase Gas-Liquid Flows in a Ladle Shroud

NASA Astrophysics Data System (ADS)

Singh, Prince K.; Mazumdar, Dipak

2018-06-01

Argon-steel flows inside a ladle shroud during teeming from a ladle to a tundish have been modelled physically. To this end, full-scale Perspex models of bloom as well as slab casting shrouds (BCS and SCS), operating with air and water, have been applied. Both open to air as well as immersed conditions were investigated with and without gas injection. Flows inside a ladle shroud under open to air and immersed conditions were found to be substantially different with a strong function of gas and liquid flow rates, collector nozzle and shroud diameters. Depending on the volumetric gas injection rate relative to liquid flow rate, different flow regimes have been observed in an immersed shroud [ i.e., 0 < ( ds/L_{s} ) ≤ 0.24 ]. At extremely low gas flow rates, [ i.e., ( Qg/Q_{L} ) ≤ 0.02 ], injected gas is completely entrained as bubbles by the down-flowing liquid resulting in a bubbly two-phase flow over the entire length of a shroud. However, with an increasing gas flow rate, two distinctly different regions start to develop within the shroud body: a free liquid jet in the upper part and a gas-liquid mixing zone below. The length of the free jet increases with an increasing gas flow rate and at significantly higher gas to liquid flow rates [ viz., ( Qg/Q_{L} )_{BCS} ≥ 0.42 ] and [ viz., ( Qg/Q_{L} )_{SCS} ≥ 0.30 ] , and the free jet is found to prevail over the entire length of the shroud. Within the range of conditions studied, it is observed that the free jet length or the line of demarcation between the jetting and two-phase mixing zone depends on gas and liquid flow rates and is specific to a particular shroud-collector nozzle system. Physical model results further indicate that a sufficiently large free jet length ( shroud length) tends to create a high pressure region inside a shroud and prevent ingression of air. Possible implications of the present findings with reference to industrial teeming practices are also discussed in the text.

Lumped Multi-Bubble Analysis of Injection Cooling System for Storage of Cryogenic Liquids

NASA Astrophysics Data System (ADS)

Saha, Pritam; Sandilya, Pavitra

2017-12-01

Storage of cryogenic liquids is a critical issue in many cryogenic applications. Subcooling of the liquid by bubbling a gas has been suggested to extend the storage period by reducing the boil-off loss. Liquid evaporation into the gas may cause liquid subcooling by extracting the latent heat of vaporization from the liquid. The present study aims at studying the factors affecting the liquid subcooling during gas injection. A lumped parameter model is presented to capture the effects of bubble dynamics (coalescence, breakup, deformation etc.) on the heat and mass transport between the gas and the liquid. The liquid subcooling has been estimated as a function of the key operating variables such as gas flow rate and gas injection temperature. Numerical results have been found to predict the change in the liquid temperature drop reasonably well when compared with the previously reported experimental results. This modelling approach can therefore be used in gauging the significance of various process variables on the liquid subcooling by injection cooling, as well as in designing and rating an injection cooling system.

Effects of bevacizumab loaded PEG-PCL-PEG hydrogel intracameral application on intraocular pressure after glaucoma filtration surgery.

PubMed

Han, Qian; Wang, Yuqi; Li, Xiabin; Peng, Ribo; Li, Ailing; Qian, Zhiyong; Yu, Ling

2015-08-01

PEG-PCL-PEG (PECE) hydrogel for intracameral injection as a sustained delivery system can get a stable release of the medication and achieve an effective local concentration. The injectable PECE hydrogel is thermosensitive nano-material which is flowing sol at low temperature and can shift to nonflowing gel at body temperature. This study evaluated the intracameral injection of bevacizumab combined with a PECE hydrogel drug release system on postoperative scarring and bleb survival after experimental glaucoma filtration surgery. The best result was achieved in the bevacizumab loaded PECE hydrogels group, which presented the lowest IOP values after surgery. And the blebs were significantly more persistent in this group. Histology, Massion trichrome staining and immunohistochemistry further demonstrated that glaucoma filtration surgery in combination with bevacizumab loaded PECE hydrogel resulted in good bleb survival due to scar formation inhibition. In conclusions, this study demonstrated that bevacizumab-loaded PECE hydrogel for intracameral injection as a sustained delivery system provide a great opportunity to increase the therapeutic efficacy of glaucoma filtration surgery.

Experimental study on the instability of Pressure Balance Injection System (PBIS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okamoto, Koji; Teshima, Hideyuki; Madarame, Haruki

1996-06-01

The Passive Safety Reactor has been developed to reduce the construction cost and to improve the safety. Japan Atomic Energy Research institute (JAERI) proposed the System-Integrated Pressurized Water Reactor (SPWR) as a Passive Safety Reactor. In the SPWR design, the Pressure Balanced Injection System (PBIS) was introduced for the passive safety concept. The water with boron in a containment vessel were passively injected into the core by the pressure difference between the containment vessel and reactor vessel at a severe accidental condition. However there are few studies on the thermo-hydraulic characteristics of the PBIS. In this study, the thermal hydraulicsmore » of the PBIS are experimentally investigated using the small scale model. The instability of the injected flow was observed in the adiabatic experiment. The instability was caused by the pressure balance between the two vessels. The mechanism of the instability are discussed, resulting in the good agreement with the experimental results. In the steam experiment, another instability was observed, which was caused by the heat balance in the main tank.« less

Estimating Preferential Flow in Karstic Aquifers Using Statistical Mixed Models

PubMed Central

Anaya, Angel A.; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J.; Meeker, John D.; Alshawabkeh, Akram N.

2013-01-01

Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless-steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the statistical mixed models used in the study. PMID:23802921

Estimating preferential flow in karstic aquifers using statistical mixed models.

PubMed

Anaya, Angel A; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J; Meeker, John D; Alshawabkeh, Akram N

2014-01-01

Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models (SMMs) are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the SMMs used in the study. © 2013, National Ground Water Association.

Bioremediation in fractured rock: 1. Modeling to inform design, monitoring, and expectations

USGS Publications Warehouse

Tiedeman, Claire; Shapiro, Allen M.; Hsieh, Paul A.; Imbrigiotta, Thomas; Goode, Daniel J.; Lacombe, Pierre; DeFlaun, Mary F.; Drew, Scott R.; Johnson, Carole D.; Williams, John H.; Curtis, Gary P.

2018-01-01

Field characterization of a trichloroethene (TCE) source area in fractured mudstones produced a detailed understanding of the geology, contaminant distribution in fractures and the rock matrix, and hydraulic and transport properties. Groundwater flow and chemical transport modeling that synthesized the field characterization information proved critical for designing bioremediation of the source area. The planned bioremediation involved injecting emulsified vegetable oil and bacteria to enhance the naturally occurring biodegradation of TCE. The flow and transport modeling showed that injection will spread amendments widely over a zone of lower‐permeability fractures, with long residence times expected because of small velocities after injection and sorption of emulsified vegetable oil onto solids. Amendments transported out of this zone will be diluted by groundwater flux from other areas, limiting bioremediation effectiveness downgradient. At nearby pumping wells, further dilution is expected to make bioremediation effects undetectable in the pumped water. The results emphasize that in fracture‐dominated flow regimes, the extent of injected amendments cannot be conceptualized using simple homogeneous models of groundwater flow commonly adopted to design injections in unconsolidated porous media (e.g., radial diverging or dipole flow regimes). Instead, it is important to synthesize site characterization information using a groundwater flow model that includes discrete features representing high‐ and low‐permeability fractures. This type of model accounts for the highly heterogeneous hydraulic conductivity and groundwater fluxes in fractured‐rock aquifers, and facilitates designing injection strategies that target specific volumes of the aquifer and maximize the distribution of amendments over these volumes.

ARC Cell Science Validation (CS-V) Payload Overview

NASA Technical Reports Server (NTRS)

Gilkerson, Nikita

2017-01-01

Automated cell biology system for laboratory and International Space Station (ISS) National Laboratory research. Enhanced cell culture platform that provides undisturbed culture maintenance, including feedback temperature control, medical grade gas supply, perfusion nutrient delivery and removal of waste, and automated experiment manipulations. Programmable manipulations include: media feeds change out, injections, fraction collections, fixation, flow rate, and temperature modification within a one-piece sterile barrier flow path. Cassette provides 3 levels of containment and allows Crew access to the bioculture chamber and flow path assembly for experiment initiation, refurbishment, or sample retrieval and preservation.

Advanced technologies and devices for inhalational anesthetic drug dosing.

PubMed

Meyer, J-U; Kullik, G; Wruck, N; Kück, K; Manigel, J

2008-01-01

Technological advances in micromechanics, optical sensing, and computing have led to innovative and reliable concepts of precise dosing and sensing of modern volatile anesthetics. Mixing of saturated desflurane flow with fresh gas flow (FGF) requires differential pressure sensing between the two circuits for precise delivery. The medical gas xenon is administered most economically in a closed circuit breathing system. Sensing of xenon in the breathing system is achieved with miniaturized and unique gas detector systems. Innovative sensing principles such as thermal conductivity and sound velocity are applied. The combination of direct injection of volatile anesthetics and low-flow in a closed circuit system requires simultaneous sensing of the inhaled and exhaled gas concentrations. When anesthetic conserving devices are used for sedation with volatile anesthetics, regular gas concentration monitoring is advised. High minimal alveolar concentration (MAC) of some anesthetics and low-flow conditions bear the risk of hypoxic gas delivery. Oxygen sensing based on paramagnetic thermal transduction has become the choice when long lifetime and one-time calibration are required. Compact design of beam splitters, infrared filters, and detectors have led to multiple spectra detector systems that fit in thimble-sized housings. Response times of less than 500 ms allow systems to distinguish inhaled from exhaled gas concentrations. The compact gas detector systems are a prerequisite to provide "quantitative anesthesia" in closed circuit feedback-controlled breathing systems. Advanced anesthesia devices in closed circuit mode employ multiple feedback systems. Multiple feedbacks include controls of volume, concentrations of anesthetics, and concentration of oxygen with a corresponding safety system. In the ideal case, the feedback system delivers precisely what the patient is consuming. In this chapter, we introduce advanced technologies and device concepts for delivering inhalational anesthetic drugs. First, modern vaporizers are described with special attention to the particularities of delivering desflurane. Delivery of xenon is presented, followed by a discussion of direct injection of volatile anesthetics and of a device designed to conserve anesthetic drugs. Next, innovative sensing technologies are presented for reliable control and precise metering of the delivered volatile anesthetics. Finally, we discuss the technical challenges of automatic control in low-flow and closed circuit breathing systems in anesthesia.

Detection of small degree of nonuniformity in dialysate flow in hollow-fiber dialyzer using proton magnetic resonance imaging.

PubMed

Osuga, T; Obata, T; Ikehira, H

2004-04-01

A small degree of nonuniformity in dialysate flow in a hollow-fiber dialyzer was detected using proton magnetic resonance imaging (MRI). Since paramagnetic ions reduce the spin-lattice relaxation time of protons around them, MRI can detect Gd in water. An aqueous solution of a chelate compound of Gd was impulsively injected into the dialysate flow path at a flow rate of 500 cm(3) /m, which is that utilized in actual dialysis. Despite the apparent elimination of Gd from the dialysate flow path by the newly injected dialysate fluid after the injection of Gd was terminated, MRI revealed that Gd remained in the interior of the hollow fiber. The observed structure pattern of the Gd concentration profile revealed that the dialysate flow had a small degree of nonuniformity despite the currently established design to restrict channeling in dialysate flow. Local nonuniformity of the hollow-fiber density and vortex generation in the dialysate flow were considered to cause the nonuniformity in the dialysate flow.

Comparison of Series of Vugs and Non-vuggy Synthetic Porous Media on Formation Damage

NASA Astrophysics Data System (ADS)

Khan, H.; DiCarlo, D. A.; Prodanovic, M.

2017-12-01

Produced water reinjection (PWRI) is an established cost-effective oil field practice where produced water is injected without any cleanup, for water flooding or disposal. Resultantly the cost of fresh injection fluid and/or processing produced water is saved. A common problem with injection of unprocessed water is formation damage in the near injection zone due to solids (fines) entrapment, causing a reduction in permeability and porosity of the reservoir. Most studies have used homogeneous porous media with unimodal grain sizes, while real world porous media often has a wide range of pores, up to and including vugs in carbonaceous rocks. Here we fabricate a series of vugs in synthetic porous media by sintering glass beads with large dissolvable inclusions. The process is found to be repeatable, allowing a similar vug configuration to be tested for different flow conditions. Bi-modal glass bead particles (25 & 100 micron) are injected at two different flow rates and three different injection concentrations. Porosity, permeability and effluent concentration are determined using CT scanning, pressure measurements and particle counting (Coulter counter), respectively. Image analysis is performed on the CT images to determine the change in vug size for each flow condition. We find that for the same flow conditions, heterogeneous media with series of vugs have an equal or greater permeability loss compared to homogeneous porous media. A significant change in permeability is observed at the highest concentration and flow rate as more particles approach the filter quickly, resulting in a greater loss in permeability in the lower end of the core. Image analysis shows the highest loss in vug size occurs at the low flow rate and highest concentration. The lower vug is completely blocked for this flow case. For all flow cases lower values of porosity are observed after the core floods. At low flow rate and medium concentration, a drastic loss in porosity is observed in the lower part of the core, after the vuggy zone. This trough is also distinctly clear in the homogeneous core for the same flow conditions. This study focuses on understanding the effect of pore heterogeneity on formation damage. We conclude that more damage is done deeper in vuggy formations at high flow rates, resulting in shorter injection cycle prior to clean up.

Impedance feedback control of microfluidic valves for reliable post processing combinatorial droplet injection.

PubMed

Axt, Brant; Hsieh, Yi-Fan; Nalayanda, Divya; Wang, Tza-Huei

2017-09-01

Droplet microfluidics has found use in many biological assay applications as a means of high-throughput sample processing. One of the challenges of the technology, however, is the ability to control and merge droplets on-demand as they flow through the microdevices. It is in the interest of developing lab-on-chip devices to be able to combinatorically program additive mixing steps for more complex multistep and multiplex assays. Existing technologies to merge droplets are either passive in nature or require highly predictable droplet movement for feedforward control, making them vulnerable to errors during high throughput operation. In this paper, we describe and demonstrate a microfluidic valve-based device for the purpose of combinatorial droplet injection at any stage in a multistep assay. Microfluidic valves are used to robustly control fluid flow, droplet generation, and droplet mixing in the device on-demand, while on-chip impedance measurements taken in real time are used as feedback to accurately time the droplet injections. The presented system is contrasted to attempts without feedback, and is shown to be 100% reliable over long durations. Additionally, content detection and discretionary injections are explored and successfully executed.

Gel performance in rheology and profile control under low-frequency vibration: coupling application of physical and chemical EOR techniques.

PubMed

Zheng, Li Ming; Pu, Chun Sheng; Liu, Jing; Ma, Bo; Khan, Nasir

2017-01-01

Flowing gel plugging and low-frequency vibration oil extraction technology have been widely applied in low-permeability formation. High probability of overlapping in action spheres of two technologies might lead to poor operating efficiency during gel injection. Study on flowing gel rheological properties under low-frequency vibration was essential, which was carried out indoor with viscosity measurement. Potential dynamic mechanisms were analyzed for the rheological variation. Under low-frequency vibration, gel rheological properties were found to be obviously influenced, with vibration delaying gel cross-linking in induction period, causing a two-stage gel viscosity change in acceleration period, and decreasing gel strength in stable period. Surface of gel system under vibration presented different fluctuating phenomenon from initial harmonic vibrating to heterogeneous fluctuating (droplet separation might appear) to final harmonic vibrating again. Dynamic displacement in unconsolidated sand pack revealed that low-frequency vibration during gel injection might be a measure to achieve deep profile control, with the gel injection depth increased by 65.8 % compared with the vibration-free sample. At last, suggestions for field test were given in the paper to achieve lower injection friction and better gel plugging efficiency.

Wet-Atmosphere Generator

NASA Technical Reports Server (NTRS)

Hamner, Richard M.; Mcguire, Janice K.

1988-01-01

Water content in gas controlled. Portable flow-control system generates nitrogen/water atmosphere having range of dew points and pressures. One use of system provides wet nitrogen for canister of wide-field camera requiring this special atmosphere. Also used to inject trace gases other than water vapor for leak testing of large vessels. Potential applications in photography, hospitals, and calibration laboratories.

Fracture Flow Characterization from Seismic and Electric Properties: Insight from Experimental and Numerical Approaches

NASA Astrophysics Data System (ADS)

Sawayama, K.; Kitamura, K.; Tsuji, T.; Fujimitsu, Y.

2017-12-01

The estimation of fluid flow and its distribution in the fracture is essential to evaluate subsurface fluid (e.g., geothermal water, ground water, oil and gas). Recently, fluid flow in the geothermal reservoir has been attracting attention to develop EGS (enhanced geothermal system) technique. To detect the fluid distribution under the ground, geophysical exploration such as seismic and electromagnetic methods have been broadly applied. For better interpretation of these exploration data, more detailed investigation about the effect of fluid on seismic and electric properties of fracture is required. In this study, we measured and calculated seismic and electric properties of a cracked rock to discuss the effect of water distribution and saturation on them as well as fluid flow. For the experimental observation, we developed the technique to measure electrical impedance, P-wave velocity and water saturation simultaneously during the fluid-flow test. The test has been conducted as follows; a cracked andesite core sample was filled with nitrogen gas (Pp = 10 MPa) under 20 MPa of confining pressure and then, brine (1wt.%-KCl, 1.75 S/m) was injected into the sample to replace the gas. During the test, water saturation, permeability, electrical impedance and P-wave velocity were measured. As a result of this experimental study, electrical impedance dramatically decreased from 105 to 103 Ω and P-wave velocity increased by 2% due to the brine injection. This remarkable change of the electrical impedance could be due to the replacement of pre-filled nitrogen gas to the brine in the broad fracture. After the brine injection, electrical impedance decreased with injection pressure by up to 40% while P-wave velocity was almost constant. This decrease of electrical impedance could be related to the flow to the narrow path (microcrack) which cannot be detected by P-wave velocity. These two types of fluid flow mechanism were also suggested from other parameters such as permeability, water saturation and saturation exponent of Archie's law. To quantify the fluid flow and its distribution in the fracture, we applied fluid flow simulation by LBM (Lattice Boltzmann Method). From this result, we calculate physical parameters by FEM and FDM and then discuss effect of fluid on them as well as their comparison with experimental results.

New horizons in local anesthesia.

PubMed

Lackey, A D

1998-08-01

The computer-controlled local anesthesia system and the TEA system present 21st-century alternatives to the traditional syringe. The TEA system is a non-invasive form of anesthesia that blocks pain electronically, using the same cellular mechanism as local chemical anesthesia. Targeted electronic anesthesia provides pain control for restorative dental procedures without the use of needles or postoperative discomfort, numbness, and swelling. The computer-assisted system outperforms syringes for traditional injections. This new system generates a precisely controlled anesthetic flow rate that eliminates the need for the operator to use thumb pressure to administer the injection. The lightweight pen-grasp handle results in greater tactile feedback, precision, operator ease, and patient comfort. The greatest advantage may be in the new techniques that it makes available. With these techniques, a dentist can target the teeth to achieve profound pulpal anesthesia, often without the annoying side effects of facial numbness. With this new advanced system in the maxillary arch, the AMSA injection offers clinical advantages over traditional anesthesia techniques, according to Dr. Mark Friedman, whom I consulted with earlier this year. In the mandibular arch, a safe and predictable PDL injection technique may replace the need for an inferior alveolar block in numerous clinical situations. The use of these modified injection techniques can have a positive influence on patient safety, patient comfort, and office productivity. Both of these systems take the fear and anxiety out of dental injections. They offer exciting advanced technology for local pain control. Significantly, if patient stress and anxiety are reduced, the operator immediately benefits. New horizons in local anesthesia offer improved opportunities for patient comfort using computer-controlled local anesthetic systems and TEA.

Fuel Injector With Shear Atomizer

NASA Technical Reports Server (NTRS)

Beal, George W.; Mills, Virgil L.; Smith, Durward B., II; Beacom, William F.

1995-01-01

Atomizer for injecting liquid fuel into combustion chamber uses impact and swirl to break incoming stream of fuel into small, more combustible droplets. Slanted holes direct flow of liquid fuel to stepped cylindrical wall. Impact on wall atomizes liquid. Air flowing past vanes entrains droplets of liquid in swirling flow. Fuel injected at pressure lower than customarily needed.

An innovative system for supplying air and fuel mixture to a combustion chamber of an engine

NASA Astrophysics Data System (ADS)

Saikumar, G. R. Bharath

2018-04-01

Conventional carburetors are being used since decades to ensure that the desired ratio of air and fuel enters the combustion chamber for combustion for the purpose of generating power in an Spark Ignition(SI) internal combustion engine. However to increase the efficiency, the carburetor system is gradually being replaced by fuel injection systems. Fuel injection systems use injectors to supply pressurized fuel into the combustion chamber. Owing to the high initial and maintenance cost, carburetors are still ruling in the low cost vehicle domain. An innovative concept is conceived, which is an alternative method to the carburetor system to supply the air and fuel mixture to a combustion chamber of an engine. This system comprises of an inner hollow cylinder with minute holes drilled along its length with an outer cylinder capable of sliding along its length or its longitudinal axis. This system is placed in the venturi instead of the conventional carburetor system. Fuel enters from the bottom inlet of the inner cylinder and flows out through the holes provided along its length. The fuel flow from the inner cylinder is dependent on the size and the number of holes exposed at that instance by the sliding outer cylinder which in turn is connected to the throttle or accelerator.

Pressure-controlled injection of guar gum stabilized microscale zerovalent iron for groundwater remediation.

PubMed

Luna, M; Gastone, F; Tosco, T; Sethi, R; Velimirovic, M; Gemoets, J; Muyshondt, R; Sapion, H; Klaas, N; Bastiaens, L

2015-10-01

The paper reports a pilot injection test of microsized zerovalent iron (mZVI) dispersed in a guar gum shear thinning solution. The test was performed in the framework of the EU research project AQUAREHAB in a site in Belgium contaminated by chlorinated aliphatic hydrocarbons (CAHs). The field application was aimed to overcome those critical aspects which hinder mZVI field injection, mainly due to the colloidal instability of ZVI-based suspensions. The iron slurry properties (iron particles size and concentration, polymeric stabilizer type and concentration, slurry viscosity) were designed in the laboratory based on several tests (reactivity tests towards contaminants, sedimentation tests and rheological measurements). The particles were delivered into the aquifer through an injection well specifically designed for controlled-pressure delivery (approximately 10 bars). The well characteristics and the critical pressure of the aquifer (i.e. the injection pressure above which fracturing occurs) were assessed via two innovative injection step rate tests, one performed with water and the other one with guar gum. Based on laboratory and field preliminary tests, a flow regime at the threshold between permeation and preferential flow was selected for mZVI delivery, as a compromise between the desired homogeneous distribution of the mZVI around the injection point (ensured by permeation flow) and the fast and effective injection of the slurry (guaranteed by high discharge rates and injection pressure, resulting in the generation of preferential flow paths). A monitoring setup was designed and installed for the real-time monitoring of relevant parameters during injection, and for a fast determination of the spatial mZVI distribution after injection via non-invasive magnetic susceptibility measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental and numerical study of the relation between flow paths and fate of a pesticide in a riparian wetland

NASA Astrophysics Data System (ADS)

Kidmose, Jacob; Dahl, Mette; Engesgaard, Peter; Nilsson, Bertel; Christensen, Britt S. B.; Andersen, Stine; Hoffmann, Carl Christian

2010-05-01

SummaryA field-scale pulse-injection experiment with the herbicide Isoproturon was conducted in a Danish riparian wetland. A non-reactive tracer (bromide) experiment was also carried out to characterize the physical transport system. Groundwater flow and reactive transport modelling was used to simulate flow paths, residence times, as well as bromide and Isoproturon distributions. The wetland can be characterized by two distinct riparian flow paths; one flow path discharges 2/3 of the incoming groundwater directly to the free water surface of the wetland near the foot of the hillslope with an average residence time of 205 days, and another flow path diffusively discharging the remaining 1/3 of the incoming groundwater to the stream with an average residence time of 425 days. The reactive transport simulations reveal that Isoproturon is retarded by a factor of 2-4, which is explained by the high organic content in the peat layer of the wetland. Isoproturon was found to be aerobically degraded with a half-life in the order of 12-80 days. Based on the quantification of flow paths, residence times and half-lives it is estimated that about 2/3 of the injected Isoproturon is removed in the wetland. Thus, close to 1/3 may find its way to the stream through overland flow. It is also possible that high concentrations of metabolites will reach the stream.

Dynamic leaching and fractionation of trace elements from environmental solids exploiting a novel circulating-flow platform.

PubMed

Mori, Masanobu; Nakano, Koji; Sasaki, Masaya; Shinozaki, Haruka; Suzuki, Shiho; Okawara, Chitose; Miró, Manuel; Itabashi, Hideyuki

2016-02-01

A dynamic flow-through microcolumn extraction system based on extractant re-circulation is herein proposed as a novel analytical approach for simplification of bioaccessibility tests of trace elements in sediments. On-line metal leaching is undertaken in the format of all injection (AI) analysis, which is a sequel of flow injection analysis, but involving extraction under steady-state conditions. The minimum circulation times and flow rates required to determine the maximum bioaccessible pools of target metals (viz., Cu, Zn, Cd, and Pb) from lake and river sediment samples were estimated using Tessier's sequential extraction scheme and an acid single extraction test. The on-line AIA method was successfully validated by mass balance studies of CRM and real sediment samples. Tessier's test in on-line AI format demonstrated to be carried out by one third of extraction time (6h against more than 17 h by the conventional method), with better analytical precision (<9.2% against >15% by the conventional method) and significant decrease in blank readouts as compared with the manual batch counterpart. Copyright © 2015 Elsevier B.V. All rights reserved.

Remedial Amendment Delivery near the Water Table Using Shear Thinning Fluids: Experiments and Numerical Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oostrom, Martinus; Truex, Michael J.; Vermeul, Vincent R.

2014-08-19

The use of shear thinning fluids (STFs) containing xanthan is a potential enhancement for emplacing a solute amendment near the water table and within the capillary fringe. Most research to date related to STF behavior has involved saturated and confined conditions. A series of flow cell experiments were conducted to investigate STF emplacement in variable saturated homogeneous and layered heterogeneous systems. Besides flow visualization using dyes, amendment concentrations and pressure data were obtained at several locations. The experiments showed that injection of STFs considerably improved the subsurface distribution near the water table by mitigating preferential flow through higher permeability zonesmore » compared to no-polymer injections. The phosphate amendment migrated with the xanthan SFT without retardation. Despite the high viscosity of the STF, no excessive mounding or preferential flow were observed in the unsaturated zone. The STOMP simulator was able to predict the experimentally observed fluid displacement and amendment concentrations reasonably well. Cross flow between layers could be interpreted as the main mechanism to transport STFs into lower permeability layers based on the observed pressure gradient and concentration data in layers of differing hydraulic conductivity.« less

Detection of phenolic compounds in flow systems based on tyrosinase-modified reticulated vitreous carbon electrodes.

PubMed

Peña, N; Reviejo, A J; Pingarrón, J M

2001-08-03

The fabrication and performance of a reticulated vitreous carbon (RVC)-based tyrosinase flow-through electrode, in which the enzyme was covalently immobilized, is reported. The bioelectrode was tested as an amperometric detector for phenolic compounds. Variables affecting the construction of the enzyme flow-through electrode such as the RVC chemical pretreatment procedure, the enzyme immobilization method in the RVC matrix, the enzyme loading and the pH value of the buffer solution used, were optimized by flow-injection with amperometric detection. A good immobilization of the enzyme in the RVC matrix, in spite of the hydrodynamic conditions, was found. The same tyrosinase-RVC electrode could be used with no significant loss of the amperometric response for around 20 days, and reproducible responses could be achieved with different electrodes constructed in the same manner. Moreover, the operational stability of the bioelectrode was tested under continuous monitorization conditions. Calibration plots by flow injection with amperometric detection at -0.20 V were obtained for phenol, 2,4-dimethylphenol; 3-chlorophenol; 4-chlorophenol; 4-chloro-3-methylphenol and 2-aminophenol, with detection limits ranging from 2 mug l(-1) (4-chloro-3-methylphenol) to 2 mg l(-1).

Design Enhancements of the Two-Dimensional, Dual Throat Fluidic Thrust Vectoring Nozzle Concept

NASA Technical Reports Server (NTRS)

Flamm, Jeffrey D.; Deere, Karen A.; Mason, Mary L.; Berrier, Bobby L.; Johnson, Stuart K.

2006-01-01

A Dual Throat Nozzle fluidic thrust vectoring technique that achieves higher thrust-vectoring efficiencies than other fluidic techniques, without sacrificing thrust efficiency has been developed at NASA Langley Research Center. The nozzle concept was designed with the aid of the structured-grid, Reynolds-averaged Navier-Stokes computational fluidic dynamics code PAB3D. This new concept combines the thrust efficiency of sonic-plane skewing with increased thrust-vectoring efficiencies obtained by maximizing pressure differentials in a separated cavity located downstream of the nozzle throat. By injecting secondary flow asymmetrically at the upstream minimum area, a new aerodynamic minimum area is formed downstream of the geometric minimum and the sonic line is skewed, thus vectoring the exhaust flow. The nozzle was tested in the NASA Langley Research Center Jet Exit Test Facility. Internal nozzle performance characteristics were defined for nozzle pressure ratios up to 10, with a range of secondary injection flow rates up to 10 percent of the primary flow rate. Most of the data included in this paper shows the effect of secondary injection rate at a nozzle pressure ratio of 4. The effects of modifying cavity divergence angle, convergence angle and cavity shape on internal nozzle performance were investigated, as were effects of injection geometry, hole or slot. In agreement with computationally predicted data, experimental data verified that decreasing cavity divergence angle had a negative impact and increasing cavity convergence angle had a positive impact on thrust vector angle and thrust efficiency. A curved cavity apex provided improved thrust ratios at some injection rates. However, overall nozzle performance suffered with no secondary injection. Injection holes were more efficient than the injection slot over the range of injection rates, but the slot generated larger thrust vector angles for injection rates less than 4 percent of the primary flow rate.

Flow analysis techniques for phosphorus: an overview.

PubMed

Estela, José Manuel; Cerdà, Víctor

2005-04-15

A bibliographical review on the implementation and the results obtained in the use of different flow analytical techniques for the determination of phosphorus is carried out. The sources, occurrence and importance of phosphorus together with several aspects regarding the analysis and terminology used in the determination of this element are briefly described. A classification as well as a brief description of the basis, advantages and disadvantages of the different existing flow techniques, namely; segmented flow analysis (SFA), flow injection analysis (FIA), sequential injection analysis (SIA), all injection analysis (AIA), batch injection analysis (BIA), multicommutated FIA (MCFIA), multisyringe FIA (MSFIA) and multipumped FIA (MPFIA) is also carried out. The most relevant manuscripts regarding the analysis of phosphorus by means of flow techniques are herein classified according to the detection instrumental technique used with the aim to facilitate their study and obtain an overall scope. Finally, the analytical characteristics of numerous flow-methods reported in the literature are provided in the form of a table and their applicability to samples with different matrixes, namely water samples (marine, river, estuarine, waste, industrial, drinking, etc.), soils leachates, plant leaves, toothpaste, detergents, foodstuffs (wine, orange juice, milk), biological samples, sugars, fertilizer, hydroponic solutions, soils extracts and cyanobacterial biofilms are tabulated.

Method and System for Weakening Shock Wave Strength at Leading Edge Surfaces of Vehicle in Supersonic Atmospheric Flight

NASA Technical Reports Server (NTRS)

Pritchett, Victor E., II (Inventor); Wang, Ten-See (Inventor); Blankson, Isaiah M. (Inventor); Daso, Endwell O. (Inventor); Farr, Rebecca Ann (Inventor); Auslender, Aaron Howard (Inventor); Plotkin, Kenneth J. (Inventor)

2015-01-01

A method and system are provided to weaken shock wave strength at leading edge surfaces of a vehicle in atmospheric flight. One or more flight-related attribute sensed along a vehicle's outer mold line are used to control the injection of a non-heated, non-plasma-producing gas into a local external flowfield of the vehicle from at least one leading-edge surface location along the vehicle's outer mold line. Pressure and/or mass flow rate of the gas so-injected is adjusted in order to cause a Rankine-Hugoniot Jump Condition along the vehicle's outer mold line to be violated.

United States Air Force Environmental Restoration Program. Guidance on Soil Vapor Extraction Optimization

DTIC Science & Technology

2001-06-01

Pump Exposed Capillary Fringe SVE System Pneumatic/ Hydraulic Fracturing Points Increased Advective Flow draw\\svehandbk1.cdr aee p1 4/5/01 022/736300...propagate further from the extraction well, increasing the advective flow zone round the well. Pneumatic and hydraulic fracturing are the primary methods...enhancing existing fractures and increasing the secondary fracture network. Hydraulic fracturing involves the injection of water or slurry into the

How does rapidly changing discharge during storm events affect transient storage and channel water balance in a headwater mountain stream?

Treesearch

Adam S. Ward; Michael N. Gooseff; Thomas J. Voltz; Michael Fitzgerald; Kamini Singha; Jay P. Zarnetske

2013-01-01

Measurements of transient storage in coupled surface-water and groundwater systems are widely made during base flow periods and rarely made during storm flow periods. We completed 24 sets of slug injections in three contiguous study reaches during a 1.25 year return interval storm event (discharge ranging from 21.5 to 434 L s1 ) in a net gaining headwater stream within...

A Numerical Study for Groundwater Flow, Heat and Solute Transport Associated with Operation of Open-loop Geothermal System in Alluvial Aquifer

NASA Astrophysics Data System (ADS)

Park, D. K.; Bae, G. O.; Lee, K. K.

2014-12-01

The open-loop geothermal system directly uses a relatively stable temperature of groundwater for cooling and heating in buildings and thus has been known as an eco-friendly, energy-saving, and cost-efficient technique. The facility for this system was installed at a site located near Paldang-dam in Han-river, Korea. Because of the well-developed alluvium, the site might be appropriate to application of this system requiring extraction and injection of a large amount of groundwater. A simple numerical experiment assuming various hydrogeologic conditions demonstrated that regional groundwater flow direction was the most important factor for efficient operation of facility in this site having a highly permeable layer. However, a comparison of river stage data and groundwater level measurements showed that the daily and seasonal controls of water level at Paldang-dam have had a critical influence on the regional groundwater flow in the site. Moreover, nitrate concentrations measured in the monitoring wells gave indication of the effect of agricultural activities around the facility on the groundwater quality. The facility operation, such as extraction and injection of groundwater, will obviously affect transport of the agricultural contaminant and, maybe, it will even cause serious problems in the normal operation. Particularly, the high-permeable layer in this aquifer must be a preferential path for quick spreadings of thermal and contaminant plumes. The objective of this study was to find an efficient, safe and stable operation plan of the open-loop geothermal system installed in this site having the complicated conditions of highly permeable layer, variable regional groundwater flow, and agricultural contamination. Numerical simulations for groundwater flow, heat and solute transport were carried out to analyze all the changes in groundwater level and flow, temperature, and quality according to the operation, respectively. Results showed that an operation plan for only the thermal efficiency of system cannot be the best in aspect of safe and stable operation related to groundwater quality. All these results concluded that it is essential to understand various and site-specific conditions of the site in a more integrated approach for the successful application of the open-loop geothermal system.

General pharmacological profile of the novel muscarinic receptor agonist SNI-2011, a drug for xerostomia in Sjögren's syndrome. 3rd communication: effects on respiratory and cardiovascular systems.

PubMed

Arisawa, Hirohiko; Fukui, Kenji; Masunaga, Hiroaki

2002-01-01

A novel muscarinic receptor agonist, SNI-2011 ((+/-)-cis-2-methylspiro[1,3-oxathiolane- 5,3'-quinuclidine]monohydrochloride hemihydrate, cevimeline, CAS 153504-70-2), is a candidate therapeutic drug for xerostomia in Sjögren's syndrome. The general pharmacological properties of this drug on the respiratory and cardiovascular systems were investigated in guinea pigs and dogs. SNI-2011 reduced the contractile force and beating rate of isolated right guinea pig atrium at 1 x 10(-6) mol/l or higher and 3 x 10(-6) mol/l or higher, respectively. SNI-2011 reduced the contractile force of isolated left atrium induced by electric stimulation at 1 x 10(-6) mol/l or higher. In anesthetized dogs, SNI-2011 caused a transient decrease in blood pressure, tachycardia and an increase in femoral arterial blood flow at 0.01 mg/kg i.v. or higher. At 1 mg/kg it caused continuous bradycardia, a decrease in femoral arterial blood flow and an increase in respiration rate in addition to the changes observed immediately after injection. A transient negative T-wave was observed as the only change in the ECG immediately after injection at 1 mg/kg. However, when SNI-2011 was injected intraduodenally, a decrease in femoral arterial blood flow, bradycardia and a tendency to increase respiration rate were observed at doses of 1 to 3 mg/kg. All these events in dogs were antagonized by atropine. These results suggest that oral administration of SNI-2011, that is the clinical administration route, can distinctly reduce the muscarinic effects on the respiratory and cardiovascular systems compared to intravenous administration.

Determination of Hypochlorite in Bleaching Products with Flower Extracts to Demonstrate the Principles of Flow Injection Analysis

ERIC Educational Resources Information Center

Ramos, Luiz Antonio; Prieto, Katia Roberta; Carvalheiro, Eder Tadeu Gomes; Carvalheiro, Carla Cristina Schmitt

2005-01-01

The use of crude flower extracts to the principle of analytical chemistry automation, with the flow injection analysis (FIA) procedure developed to determine hypochlorite in household bleaching products was performed. The FIA comprises a group of techniques based on injection of a liquid sample into a moving, nonsegmented carrier stream of a…

CARS Temperature Measurements in a Hypersonic Propulsion Test Facility

NASA Technical Reports Server (NTRS)

Jarrett, Olin, Jr.; Smith, M. W.; Antcliff, R. R.; Northam, G. Burt; Cutler, A. D.; Capriotti, D. P.; Taylor, D. J.

1990-01-01

Nonintrusive diagnostic measurements were performed in the supersonic reacting flow of the Hypersonic Propulsion Test Cell 2 at NASA-Langley. A Coherent Anti-stokes Raman Spectroscopy (CARS) system was assembled specifically for the test cell environment. System design considerations were: (1) test cell noise and vibration; (2) contamination from flow field or atmospheric borne dust; (3) unwanted laser or electrically induced combustion (inside or outside the duct); (4) efficient signal collection; (5) signal splitting to span the wide dynamic range present throughout the flow field; (6) movement of the sampling volume in the flow; and (7) modification of the scramjet model duct to permit optical access to the reacting flow with the CARS system. The flow in the duct was a nominal Mach 2 flow with static pressure near one atmosphere. A single perpendicular injector introduced hydrogen into the flow behind a rearward facing step. CARS data was obtained in three planes downstream of the injection region. At least 20 CARS data points were collected at each of the regularly spaced sampling locations in each data plane. Contour plots of scramjet combustor static temperature in a reacting flow region are presented.

Hydraulic Shearing and Hydraulic Jacking Observed during Hydraulic Stimulations in Fractured Geothermal Reservoir in Pohang, Korea

NASA Astrophysics Data System (ADS)

Min, K. B.; Park, S.; Xie, L.; Kim, K. I.; Yoo, H.; Kim, K. Y.; Choi, J.; Yoon, K. S.; Yoon, W. S.; Lee, T. J.; Song, Y.

2017-12-01

Enhanced Geothermal System (EGS) relies on sufficient and irreversible enhancement of reservoir permeability through hydraulic stimulation and possibility of such desirable change of permeability is an open question that can undermine the universality of EGS concept. We report results of first hydraulic stimulation campaign conducted in two deep boreholes in fractured granodiorite geothermal reservoir in Pohang, Korea. Borehole PX-1, located at 4.22 km, was subjected to the injection of 3,907 m3 with flow rate of up to 18 kg/s followed by bleeding off of 1,207 m3. The borehole PX-2, located at 4.35 km, was subjected to the injection of 1,970 m3 with flow rate of up to 46 kg/sIn PX-1, a sharp distinct decline of wellhead pressure was observed at around 16 MPa of wellhead pressure which was similar to the predicted injection pressure to induce hydraulic shearing. Injectivity interpretation before and after the hydraulic shearing indicates that permanent increase of permeability was achieved by a factor of a few. In PX-2, however, injectivity was very small and hydraulic shearing was not observed due possibly to the near wellbore damage made by the remedying process of lost circulation such as using lost circulation material during drilling. Flow rate of larger than 40 kg/s was achieved at very high well head pressure of nearly 90 MPa. Hydraulic jacking, that is reversible opening and closure of fracture with change of injection pressure, was clearly observed. Although sharp increase of permeability due to fracture opening was achieved with elevated injection pressure, the increased permeability was reversed with decreased injection pressure.Two contrasting response observed in the same reservoir at two different boreholes which is apart only 600 m apart provide important implication that can be used for the stimulation strategy for EGS.This work was supported by the New and Renewable Energy Technology Development Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) through a grant funded by the Korean Government's Ministry of Trade, Industry & Energy (No. 20123010110010).

Determination of total mercury in environmental and biological samples by flow injection cold vapour atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Murphy, James; Jones, Phil; Hill, Steve J.

1996-12-01

A simple and accurate method has been developed for the determination of total mercury in environmental and biological samples. The method utilises an off-line microwave digestion stage followed by analysis using a flow injection system with detection by cold vapour atomic absorption spectrometry. The method has been validated using two certified reference materials (DORM-1 dogfish and MESS-2 estuarine sediment) and the results agreed well with the certified values. A detection limit of 0.2 ng g -1 Hg was obtained and no significant interference was observed. The method was finally applied to the determination of mercury in river sediments and canned tuna fish, and gave results in the range 0.1-3.0 mg kg -1.

Design and development of an automated flow injection instrument for the determination of arsenic species in natural waters.

PubMed

Hanrahan, Grady; Fan, Tina K; Kantor, Melanie; Clark, Keith; Cardenas, Steven; Guillaume, Darrell W; Khachikian, Crist S

2009-10-01

The design and development of an automated flow injection instrument for the determination of arsenite [As(III)] and arsenate [As(V)] in natural waters is described. The instrument incorporates solenoid activated self-priming micropumps and electronic switching valves for controlling the fluidics of the system and a miniature charge-coupled device spectrometer operating in a graphical programming environment. The limits of detection were found to be 0.79 and 0.98 microM for As(III) and As(V), respectively, with linear range of 1-50 microM. Spiked ultrapure water samples were analyzed and recoveries were found to be 97%-101% for As(III) and 95%-99% for As(V), respectively. Future directions in terms of automation, optimization, and field deployment are discussed.

Simplex optimization of the variables influencing the determination of pefloxacin by time-resolved chemiluminescence

NASA Astrophysics Data System (ADS)

Murillo Pulgarín, José A.; Alañón Molina, Aurelia; Jiménez García, Elisa

2018-03-01

A new chemiluminescence (CL) detection system combined with flow injection analysis (FIA) for the determination of Pefloxacin is proposed. The determination is based on an energy transfer from Pefloxacin to terbium (III). The metal ion enhances the weak CL signal produced by the KMnO4/H2SO3/Pefloxacin system. A modified simplex method was used to optimize chemical and instrumental variables. The influence of the interaction of the permanganate, Tb (III), sodium sulphite and sulphuric acid concentrations, flow rate and injected sample volume was thoroughly investigated by using a modified simplex optimization procedure. The results revealed a strong direct relationship between flow rate and CL intensity throughout the studied range that was confirmed by a gamma test. The response factor for the CL emission intensity was used to assess performance in order to identify the optimum conditions for maximization of the response. Under such conditions, the CL response was proportional to the Pefloxacin concentration over a wide range. The detection limit as calculated according to Clayton's criterion 13.7 μg L- 1. The analyte was successfully determined in milk samples with an average recovery of 100.6 ± 9.8%.

A Microwave Flow Detector for Gradient Elution Liquid Chromatography.

PubMed

Ye, Duye; Wang, Weizheng; Moline, David; Islam, Md Saiful; Chen, Feng; Wang, Pingshan

2017-10-17

This study presents a microwave flow detector technique for liquid chromatography (LC) application. The detector is based on a tunable microwave interferometer (MIM) with a vector network analyzer (VNA) for signal measurement and a computer for system control. A microstrip-line-based 0.3 μL flow cell is built and incorporated into the MIM. With syringe pump injection, the detector is evaluated by measuring a few common chemicals in DI water at multiple frequencies from 0.98 to 7.09 GHz. Less than 30 ng minimum detectable quantity (MDQ) is demonstrated. An algorithm is provided and used to obtain sample dielectric permittivity at each frequency point. When connected to a commercial HPLC system and injected with a 10 μL aliquot of 10 000 ppm caffeine DI-water solution, the microwave detector yields a signal-to-noise ratio (SNR) up to 10 under isocratic and gradient elution operations. The maximum sampling rate is 20 Hz. The measurements show that MIM tuning, aided by a digital tunable attenuator (DTA), can automatically adjust MIM operation to retain detector sensitivity when mobile phase changes. Furthermore, the detector demonstrates a capability to quantify coeluted vitamin E succinate (VES) and vitamin D 3 (VD 3 ).

A Numerical Simulation of a Normal Sonic Jet into a Hypersonic Cross-Flow

NASA Technical Reports Server (NTRS)

Jeffries, Damon K.; Krishnamurthy, Ramesh; Chandra, Suresh

1997-01-01

This study involves numerical modeling of a normal sonic jet injection into a hypersonic cross-flow. The numerical code used for simulation is GASP (General Aerodynamic Simulation Program.) First the numerical predictions are compared with well established solutions for compressible laminar flow. Then comparisons are made with non-injection test case measurements of surface pressure distributions. Good agreement with the measurements is observed. Currently comparisons are underway with the injection case. All the experimental data were generated at the Southampton University Light Piston Isentropic Compression Tube.

Mathematical modeling heat and mass transfer processes in porous media

NASA Astrophysics Data System (ADS)

Akhmed-Zaki, Darkhan

2013-11-01

On late development stages of oil-fields appears a complex problem of oil-recovery reduction. One of solution approaches is injecting of surfactant together with water in the form of active impurities into the productive layer - for decreasing oil viscosity and capillary forces between ``oil-water'' phases system. In fluids flow the surfactant can be in three states: dissolved in water, dissolved in oil and adsorbed on pore channels' walls. The surfactant's invasion into the reservoir is tracked by its diffusion with reservoir liquid and mass-exchange with two phase (liquid and solid) components of porous structure. Additionally, in this case heat exchange between fluids (injected, residual) and framework of porous medium has practical importance for evaluating of temperature influences on enhancing oil recovery. Now, the problem of designing an adequate mathematical model for describing a simultaneous flowing heat and mass transfer processes in anisotropic heterogeneous porous medium -surfactant injection during at various temperature regimes has not been fully researched. In this work is presents a 2D mathematical model of surfactant injections into the oil reservoir. Description of heat- and mass transfer processes in a porous media is done through differential and kinetic equations. For designing a computational algorithm is used modify version of IMPES method. The sequential and parallel computational algorithms are developed using an adaptive curvilinear meshes which into account heterogeneous porous structures. In this case we can evaluate the boundaries of our process flows - fronts (``invasion'', ``heat'' and ``mass'' transfers), according to the pressure, temperature, and concentration gradient changes.

Leachate flow around a well in MSW landfill: Analysis of field tests using Richards model.

PubMed

Slimani, R; Oxarango, L; Sbartai, B; Tinet, A-J; Olivier, F; Dias, D

2017-05-01

During the lifespan of a Municipal Solid Waste landfill, its leachate drainage system may get clogged. Then, as a consequence of rainfall, leachate generation and possibly leachate injection, the moisture content in the landfill increases to the point that a leachate mound could be created. Therefore, pumping the leachate becomes a necessary solution. This paper presents an original analysis of leachate pumping and injection in an instrumented well. The water table level around the well is monitored by nine piezometers which allow the leachate flow behaviour to be captured. A numerical model based on Richards equation and an exponential relationship between saturated hydraulic conductivity and depth is used to analyze the landfill response to pumping and injection. Decreasing permeability with depth appears to have a major influence on the behaviour of the leachate flow. It could have a drastic negative impact on the pumping efficiency with a maximum quasi-stationary pumping rate limited to approximately 1m 3 /h for the tested well and the radius of influence is less than 20m. The numerical model provides a reasonable description of both pumping and injection tests. However, an anomalous behaviour observed at the transition between pumping and recovery phases is observed. This could be due to a limitation of the Richards model in that it neglects the gas phase behaviour and other double porosity heterogeneous effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radial lean direct injection burner

DOEpatents

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.

Energy-beam-driven rapid fabrication system

DOEpatents

Keicher, David M.; Atwood, Clinton L.; Greene, Donald L.; Griffith, Michelle L.; Harwell, Lane D.; Jeantette, Francisco P.; Romero, Joseph A.; Schanwald, Lee P.; Schmale, David T.

2002-01-01

An energy beam driven rapid fabrication system, in which an energy beam strikes a growth surface to form a molten puddle thereon. Feed powder is then injected into the molten puddle from a converging flow of feed powder. A portion of the feed powder becomes incorporated into the molten puddle, forcing some of the puddle contents to freeze on the growth surface, thereby adding an additional layer of material. By scanning the energy beam and the converging flow of feed powder across the growth surface, complex three-dimensional shapes can be formed, ready or nearly ready for use. Nearly any class of material can be fabricated using this system.

Active Flow Separation Control of a Stator Vane Using Surface Injection in a Multistage Compressor Experiment

NASA Technical Reports Server (NTRS)

Culley, Dennis E.; Bright, Michelle M.; Prahst, Patricia S.; Strazisar, Anthony J.

2003-01-01

Micro-flow control actuation embedded in a stator vane was used to successfully control separation and improve near stall performance in a multistage compressor rig at NASA Glenn. Using specially designed stator vanes configured with internal actuation to deliver pulsating air through slots along the suction surface, a research study was performed to identify performance benefits using this microflow control approach. Pressure profiles and unsteady pressure measurements along the blade surface and at the shroud provided a dynamic look at the compressor during microflow air injection. These pressure measurements lead to a tracking algorithm to identify the onset of separation. The testing included steady air injection at various slot locations along the vane. The research also examined the benefit of pulsed injection and actively controlled air injection along the stator vane. Two types of actuation schemes were studied, including an embedded actuator for on-blade control. Successful application of an online detection and flow control scheme will be discussed. Testing showed dramatic performance benefit for flow reattachment and subsequent improvement in diffusion through the use of pulsed controlled injection. The paper will discuss the experimental setup, the blade configurations, and preliminary CFD results which guided the slot location along the blade. The paper will also show the pressure profiles and unsteady pressure measurements used to track flow control enhancement, and will conclude with the tracking algorithm for adjusting the control.

Coupled Viscous Fluid Flow and Joint Deformation Analysis for Grout Injection in a Rock Joint

NASA Astrophysics Data System (ADS)

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 injected grout volume.

Pretest analysis document for Test S-NH-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Streit, J.E.; Owca, W.A.

This report documents the pretest analysis calculation completed with the RELAP5/MOD2/CY3601 code for Semiscale MOD-2C Test S-NH-2. The test will simulate the transient that results from the shear in a small diameter penetration of a cold leg, equivalent to 2.1% of the cold leg flow area. The high pressure injection system is assumed to be inoperative throughout the transient. The recovery procedure consists of latching open both steam generator atmospheric dump valves, supplying both steam generators with auxiliary feedwater system is assumed to be partially inoperative so the auxiliary feedwater flow is degraded. Recovery will be initiated upon a peakmore » cladding temperature of 811/sup 0/K (1000/sup 0/F). The test will be terminated when primary pressure has been reduced to the low pressure injection system setpoint of 1.38 MPa (200 psia). The calculated results indicate that the test objectives can be achieved and the proposed test scenario poses no threat to personnel or to plant integrity. 7 refs., 16 figs., 2 tabs.« less

Advanced Methods for Aircraft Engine Thrust and Noise Benefits: Nozzle-Inlet Flow Analysis

NASA Technical Reports Server (NTRS)

Morgan, Morris H.; Gilinsky, Mikhail; Patel, Kaushal; Coston, Calvin; Blankson, Isaiah M.

2003-01-01

The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analyses for advanced aircraft and rocket engines. Results obtained are based on analytical methods, numerical simulations and experimental tests at the NASA LaRC and Hampton University computer complexes and experimental facilities. The main objective of this research is injection, mixing and combustion enhancement in propulsion systems. The sub-projects in the reporting period are: (A) Aero-performance and acoustics of Telescope-shaped designs. The work included a pylon set application for SCRAMJET. (B) An analysis of sharp-edged nozzle exit designs for effective fuel injection into the flow stream in air-breathing engines: triangular-round and diamond-round nozzles. (C) Measurement technique improvements for the HU Low Speed Wind Tunnel (HU LSWT) including an automatic data acquisition system and a two component (drag-lift) balance system. In addition, a course in the field of aerodynamics was developed for the teaching and training of HU students.

Peroxyoxalate chemiluminescence detection of condensates of malondialdehyde with thiobarbituric acids using a flow system.

PubMed

Nakashima, K; Nagata, M; Takahashi, M; Akiyama, S

1992-01-01

The peroxyoxalate chemiluminescence(CL) detection method for the evaluation of the CL intensity of malondialdehyde(MDA) condensates with seven 2-thiobarbituric acid derivatives is described. The method consists of a flow injection technique together with a CL detection system using bis(2,4,6-trichlorophenyl) oxalate(TCPO) and hydrogen peroxide as chemiluminogenic reagents. Linear correlations between CL intensity and concentration are obtained for pmol levels of condensates. Among the condensates, 1,3-diethyl-2-thiobarbituric acid(DETBA)-MDA shows the largest CL intensity. High performance liquid chromatography (HPLC)/CL detection of DETBA-MDA and 1,3-diphenyl-2-thiobarbituric acid(DPTBA)-MDA using a mixture of TCPO and hydrogen peroxide in acetonitrile as a postcolumn reagent solution is also described. The detection limits for DETBA-MDA and DPTBA-MDA are 20 and 200 fmol, respectively, per 20 microL injection at a signal-to-noise ratio of 2. This HPLC/CL detection system was applied to the determination of MDA in rat brains by using DETBA as a fluorescent derivatizing reagent.

Optimization of a jet-propelled particle injection system for the uniform transdermal delivery of drug/vaccine.

PubMed

Liu, Yi; Kendall, Mark A F

2007-08-01

A jet-propelled particle injection system, the biolistics, has been developed and employed to accelerate micro-particles for transdermal drug delivery. We have examined a prototype biolistic device employing a converging-diverging supersonic nozzle (CDSN), and found that the micro-particles were delivered with a wide velocity range (200-800 m/s) and spatial distribution. To provide a controllable system for transdermal drug delivery, we present a contoured shock-tube (CST) concept and its embodiment device. The CST configuration utilizes a quasi-steady, quasi-one dimensional and shock-free supersonic flow to deliver the micro-particles with an almost uniform velocity (the mean velocity and the standard deviation, 699 +/- 4.7 m/s) and spatial distribution. The transient gas and particle dynamics in both prototype devices are interrogated with the validated computational fluid dynamics (CFD) approach. The predicted results for static pressure and Mach number histories, gas flow structures, particle velocity distributions and gas-particle interactions are presented and interpreted. The implications for clinical uses are discussed. (c) 2007 Wiley Periodicals, Inc.

Sequential injection-bead injection-lab-on-valve coupled to high-performance liquid chromatography for online renewable micro-solid-phase extraction of carbamate residues in food and environmental samples.

PubMed

Vichapong, Jitlada; Burakham, Rodjana; Srijaranai, Supalax; Grudpan, Kate

2011-07-01

A sequential injection-bead injection-lab-on-valve system was hyphenated to HPLC for online renewable micro-solid-phase extraction of carbamate insecticides. The carbamates studied were isoprocarb, methomyl, carbaryl, carbofuran, methiocarb, promecarb, and propoxur. LiChroprep(®) RP-18 beads (25-40 μm) were employed as renewable sorbent packing in a microcolumn situated inside the LOV platform mounted above the multiposition valve of the sequential injection system. The analytes sorbed by the microcolumn were eluted using 80% acetonitrile in 0.1% acetic acid before online introduction to the HPLC system. Separation was performed on an Atlantis C-18 column (4.6 × 150 mm, 5 μm) utilizing gradient elution with a flow rate of 1.0 mL/min and a detection wavelength at 270 nm. The sequential injection system offers the means of performing automated handling of sample preconcentration and matrix removal. The enrichment factors ranged between 20 and 125, leading to limits of detection (LODs) in the range of 1-20 μg/L. Good reproducibility was obtained with relative standard deviations of <0.7 and 5.4% for retention time and peak area, respectively. The developed method has been successfully applied to the determination of carbamate residues in fruit, vegetable, and water samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterisation of acoustic energy content in an experimental combustion chamber with and without external forcing

NASA Astrophysics Data System (ADS)

Webster, S.; Hardi, J.; Oschwald, M.

2015-03-01

The influence of injection conditions on rocket engine combustion stability is investigated for a sub-scale combustion chamber with shear coaxial injection elements and the propellant combination hydrogen-oxygen. The experimental results presented are from a series of tests conducted at subcritical and supercritical pressures for oxygen and for both ambient and cryogenic temperature hydrogen. The stability of the system is characterised by the root mean squared amplitude of dynamic combustion chamber pressure in the upper part of the acoustic spectrum relevant for high frequency combustion instabilities. Results are presented for both unforced and externally forced combustion chamber configurations. It was found that, for both the unforced and externally forced configurations, the injection velocity had the strongest influence on combustion chamber stability. Through the use of multivariate linear regression the influence of hydrogen injection temperature and hydrogen injection mass flow rate were best able to explain the variance in stability for dependence on injection velocity ratio. For unforced tests turbulent jet noise from injection was found to dominate the energy content of the signal. For the externally forced configuration a non-linear regression model was better able to predict the variance, suggesting the influence of non-linear behaviour. The response of the system to variation of injection conditions was found to be small; suggesting that the combustion chamber investigated in the experiment is highly stable.

Fluid Dynamics of Carbon Dioxide Disposal into Saline Aquifers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, Julio Enrique

2003-01-01

Injection of carbon dioxide (CO 2) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). Large-scale injection of CO 2 will induce a variety of coupled physical and chemical processes, including multiphase fluid flow, fluid pressurization and changes in effective stress, solute transport, and chemical reactions between fluids and formation minerals. This work addresses some of these issues with special emphasis given to the physics of fluid flow in brine formations. An investigation of the thermophysical properties of pure carbon dioxide, water and aqueous solutions of CO 2 and NaCl has beenmore » conducted. As a result, accurate representations and models for predicting the overall thermophysical behavior of the system CO 2-H 2O-NaCl are proposed and incorporated into the numerical simulator TOUGH2/ECO2. The basic problem of CO 2 injection into a radially symmetric brine aquifer is used to validate the results of TOUGH2/ECO2. The numerical simulator has been applied to more complex flow problem including the CO 2 injection project at the Sleipner Vest Field in the Norwegian sector of the North Sea and the evaluation of fluid flow dynamics effects of CO 2 injection into aquifers. Numerical simulation results show that the transport at Sleipner is dominated by buoyancy effects and that shale layers control vertical migration of CO 2. These results are in good qualitative agreement with time lapse surveys performed at the site. High-resolution numerical simulation experiments have been conducted to study the onset of instabilities (viscous fingering) during injection of CO 2 into saline aquifers. The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO 2) the viscosity of carbon dioxide can be less than the viscosity of the aqueous phase by a factor of 15. Because of the lower viscosity, the CO 2 displacement front will have a tendency towards instability. Preliminary simulation results show good agreement between classical instability solutions and numerical predictions of finger growth and spacing obtained using different gas/liquid viscosity ratios, relative permeability and capillary pressure models. Further studies are recommended to validate these results over a broader range of conditions.« less

A Dual-Plane PIV Study of Turbulent Heat Transfer Flows

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Wroblewski, Adam C.; Locke, Randy J.

2016-01-01

Thin film cooling is a widely used technique in turbomachinery and rocket propulsion applications, where cool injection air protects a surface from hot combustion gases. The injected air typically has a different velocity and temperature from the free stream combustion flow, yielding a flow field with high turbulence and large temperature differences. These thin film cooling flows provide a good test case for evaluating computational model prediction capabilities. The goal of this work is to provide a database of flow field measurements for validating computational flow prediction models applied to turbulent heat transfer flows. In this work we describe the application of a Dual-Plane Particle Image Velocimetry (PIV) technique in a thin film cooling wind tunnel facility where the injection air stream velocity and temperatures are varied in order to provide benchmark turbulent heat transfer flow field measurements. The Dual-Plane PIV data collected include all three components of velocity and all three components of vorticity, spanning the width of the tunnel at multiple axial measurement planes.

Combustion of hydrogen injected into a supersonic airstream (a guide to the HISS computer program)

NASA Technical Reports Server (NTRS)

Dyer, D. F.; Maples, G.; Spalding, D. B.

1976-01-01

A computer program based on a finite-difference, implicit numerical integration scheme is described for the prediction of hydrogen injected into a supersonic airstream at an angle ranging from normal to parallel to the airstream main flow direction. Results of calculations for flow and thermal property distributions were compared with 'cold flow data' taken by NASA/Langley and show excellent correlation. Typical results for equilibrium combustion are presented and exhibit qualitatively plausible behavior. Computer time required for a given case is approximately one minute on a CDC 7600. A discussion of the assumption of parabolic flow in the injection region is given which demonstrates that improvement in calculation in this region could be obtained by a partially-parabolic procedure which has been developed. It is concluded that the technique described provides an efficient and reliable means for analyzing hydrogen injection into supersonic airstreams and the subsequent combustion.

Apparatus and method for continuous production of materials

DOEpatents

Chang, Chih-hung; Jin, Hyungdae

2014-08-12

Embodiments of a continuous-flow injection reactor and a method for continuous material synthesis are disclosed. The reactor includes a mixing zone unit and a residence time unit removably coupled to the mixing zone unit. The mixing zone unit includes at least one top inlet, a side inlet, and a bottom outlet. An injection tube, or plurality of injection tubes, is inserted through the top inlet and extends past the side inlet while terminating above the bottom outlet. A first reactant solution flows in through the side inlet, and a second reactant solution flows in through the injection tube(s). With reference to nanoparticle synthesis, the reactant solutions combine in a mixing zone and form nucleated nanoparticles. The nucleated nanoparticles flow through the residence time unit. The residence time unit may be a single conduit, or it may include an outer housing and a plurality of inner tubes within the outer housing.

Enhanced Remedial Amendment Delivery to Subsurface Using Shear Thinning Fluid and Aqueous Foam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Lirong; Szecsody, James E.; Oostrom, Martinus

2011-04-23

A major issue with in situ subsurface remediation is the ability to achieve an even spatial distribution of remedial amendments to the contamination zones in an aquifer or vadose zone. Delivery of amendment to the aquifer using shear thinning fluid and to the vadose zone using aqueous foam has the potential to enhance the amendment distribution into desired locations and improve the remediation. 2-D saturated flow cell experiments were conducted to evaluate the enhanced sweeping, contaminant removal, and amendment persistence achieved by shear thinning fluid delivery. Bio-polymer xanthan gum solution was used as the shear thinning fluid. Unsaturated 1-D columnmore » and 2-D flow cell experiments were conducted to evaluate the mitigation of contaminant mobilization, amendment uniform distribution enhancement, and lateral delivery improvement by foam delivery. Surfactant sodium lauryl ether sulfate was used as the foaming agent. It was demonstrated that the shear thinning fluid injection enhanced the fluid sweeping over a heterogeneous system and increased the delivery of remedial amendment into low-permeability zones. The persistence of the amendment distributed into the low-perm zones by the shear thinning fluid was prolonged compared to that of amendment distributed by water injection. Foam delivery of amendment was shown to mitigate the mobilization of highly mobile contaminant from sediments under vadose zone conditions. Foam delivery also achieved more uniform amendment distribution in a heterogeneous unsaturated system, and demonstrated remarkable increasing in lateral distribution of the injected liquid compared to direct liquid injection.« less

Mechanical properties of the gastro-esophageal junction in health, achalasia, and scleroderma.

PubMed

Mearin, F; Fonollosa, V; Vilardell, M; Malagelada, J R

2000-07-01

Manometric assessment of the gastro-esophageal junction (GEJ) is deceptive in that ignores key dynamic properties of the junction, such as resistance to flow and compliance. Our aim was to investigate the mechanical properties of the GEJ comprising intraluminal pressure (measured by manometry), resistance to flow and compliance (measured by resistometry). We studied 8 healthy subjects, 11 patients with achalasia and 11 patients with scleroderma. We used a pneumatic resistometer, previously developed and validated in our laboratory. The resistometer consists of a flaccid polyurethane 5-cm cylinder connected to an electronically regulated nitrogen-injection system; the instrument records nitrogen flow through the cylinder while maintaining a constant pressure gradient between its proximal and distal ends. By placing the cylinder successively in the proximal stomach and along the GEJ we measured the GEJ-gastric resistance gradient (GEJ resistance minus gastric resistance) and were able to calculate the cumulative resistance (sum of resistance exerted at each pressure level), peak resistance (at any injection pressure), nil resistance point (injection pressure in mmHg at which GEJ resistance equals gastric resistance), and compliance slope (flow/pressure relationship). We found that GEJ resistance to flow (cumulative resistance, peak resistance, and nil resistance point) is significantly increased in achalasia and decreased in scleroderma (P < 0.05 versus health) while GEJ compliance is diminished in achalasia (P < 0.05 versus health) and normal in scleroderma. Achalasia is a disease characterized by increased GEJ resistance and rigidity. By contrast, although scleroderma is characterized by decreased GEJ resistance, GEJ compliance may be normal.

Flow in a porous nozzle with massive wall injection

NASA Technical Reports Server (NTRS)

Kinney, R. B.

1973-01-01

An analytical and experimental investigation has been conducted to determine the effect of massive wall injection on the flow characteristics in a nozzle. The experiments were performed on a water table with a porous-nozzle test section. This had 45 deg and 15 deg half angles of convergence and divergence, respectively, throat radius of 2.5 inches, and throat width of 3 inches. The hydraulic analogy was employed to qualitatively extend the results to a compressible gas flow through the nozzle. An analysis of the water table flow was made using a one-dimensional flow assumption in the continuity and momentum equations. An analysis of a compressible flow in a nozzle was made in a manner analogous to that for the water flow. It is shown that the effect of blowing is to move the sonic position downstream of the geometric throat. Similar results were determined for the incompressible water table flow. Limited photographic results are presented for an injection of air, CO2, and Freon-12 into a main-stream air flow in a convergent-divergent nozzle. Schlieren photographs were used to visualize the flow.

Constraining the effects of permeability uncertainty for geologic CO2 sequestration in a basalt reservoir

NASA Astrophysics Data System (ADS)

Jayne, R., Jr.; Pollyea, R.

2016-12-01

Carbon capture and sequestration (CCS) in geologic reservoirs is one strategy for reducing anthropogenic CO2 emissions from large-scale point-source emitters. Recent developments at the CarbFix CCS pilot in Iceland have shown that basalt reservoirs are highly effective for permanent mineral trapping on the basis of CO2-water-rock interactions, which result in the formation of carbonates minerals. In order to advance our understanding of basalt sequestration in large igneous provinces, this research uses numerical simulation to evaluate the feasibility of industrial-scale CO2 injections in the Columbia River Basalt Group (CRBG). Although bulk reservoir properties are well constrained on the basis of field and laboratory testing from the Wallula Basalt Sequestration Pilot Project, there remains significant uncertainty in the spatial distribution of permeability at the scale of individual basalt flows. Geostatistical analysis of hydrologic data from 540 wells illustrates that CRBG reservoirs are reasonably modeled as layered heterogeneous systems on the basis of basalt flow morphology; however, the regional dataset is insufficient to constrain permeability variability at the scale of an individual basalt flow. As a result, permeability distribution for this modeling study is established by centering the lognormal permeability distribution in the regional dataset over the bulk permeability measured at Wallula site, which results in a spatially random permeability distribution within the target reservoir. In order to quantify the effects of this permeability uncertainty, CO2 injections are simulated within 50 equally probable synthetic reservoir domains. Each model domain comprises three-dimensional geometry with 530,000 grid blocks, and fracture-matrix interaction is simulated as interacting continua for the two low permeability layers (flow interiors) bounding the injection zone. Results from this research illustrate that permeability uncertainty at the scale of individual basalt flows may significantly impact both injection pressure accumulation and CO2 distribution.

Evolution and transition mechanisms of internal swirling flows with tangential entry

NASA Astrophysics Data System (ADS)

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.

Flow-injection chemiluminescence determination of acetylsalicylic acid based on its enhancing effect on the lucigenin–hydrogen peroxide system.

PubMed

Wabaidur, S M; Alam, S M; Alothmana, Z A; Eldesokya, Gaber

2014-09-01

A sensitive flow-injection chemiluminescence method for the determination of acetylsalicylic acid is described. It is based on the enhanced chemiluminescent emission of the alkaline lucigenin–H2O2 system by acetylsalicylic acid. The difference in chemiluminescent intensity of alkaline lucigenin–H2O2 in the presence of acetylsalicylic acid from that in the absence of acetylsalicylic acid was linear at acetylsalicylic acid concentrations in the range of 0.0029–47.37 μg/mL, with detection and quantification limits of 0.0011 and 0.0029 μg/mL, respectively. The correlation coefficient of the working curve was 0.9983. The relative standard deviation (n = 10) for 25 μg/mL acetylsalicylic acid is 1.95%. All experimental parameters were optimized. The method was successfully applied to the determination of acetylsalicylic acid in pharmaceutical preparations. The recovery results obtained by the method were satisfactory.

Vitamin A determination in milk samples based on the luminol-periodate chemiluminescence system.

PubMed

Rishi, Lubna; Yaqoob, Mohammad; Waseem, Amir; Nabi, Abdul

2014-01-01

A simple and rapid flow injection (FI) method for the determination of retinyl acetate is reported based on its enhancing effect on the luminol-periodate chemiluminescence (CL) system in an alkaline medium. The detection limit (3s×blank) was 8.0×10⁻⁸ mol L⁻¹, with an injection throughput of 90 h⁻¹. The method allows linear increase of CL intensity over the retinyl acetate concentration range of 1.0-100×10⁻⁷ mol L⁻¹ (R²=0.9996) with relative standard deviations of 2.4% (n=10) for 5.0×10⁻⁷ mol L⁻¹. The key chemical and physical variables (reagent concentrations, flow rates, sample volume, and photomultiplier tube (PMT) voltage) were optimized and potential interferences were investigated. The method was successfully applied to human milk, fresh cow's milk and infant milk-based formulas and the results were in good agreement with the previously reported HPLC method. A brief discussion on the possible CL reaction mechanism is also presented.

[Age-associated peculiarities of microcirculation system in skeletal muscles and their role in muscle work capacity in human aging (author's transl)].

PubMed

Korkusko, O V; Sarkisov, K G; Frajfel'd, V E

1982-01-01

The muscle blood flow was investigated at rest (MBFR) and after physical load under ischemia conditions (maximal muscle blood flow--MMBF) in 87 practically healthy persons (45 women and 42 men) aged 20--90. The state of muscle blood flow was evaluated by means of the clearance of 133xenon injected into M. tibialis anterior. The data obtained showed a decrease of MBFR and MMBF in older people as compared with younger subjects. In realization of this phenomenon a decrease in muscle capillarisation and a reduction in reactivity of microcirculatory link of vascular system plays an increasingly greater role with aging. The reduction in muscle blood flow forms a circulatory component of the age-associated hypoxia. This fact results in a decrease of muscle blood flow and limits the functional capacity of skeletal muscle under conditions of activity.

The measurement of skin lymph flow by isotope clearance--reliability, reproducibility, injection dynamics, and the effect of massage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mortimer, P.S.; Simmonds, R.; Rezvani, M.

1990-12-01

The measurement of skin lymph flow was investigated using an isotope clearance technique (ICT). Multiple lymph flow determinations were undertaken in the skin of anaesthetized large white pigs to test for reproducibility, ascertain the most suitable tracer, study the influence of injection dynamics, and observe the effect of massage as a stimulus to lymph flow. Blood clearance of tracer was also investigated. Results demonstrated that lymphatic clearance is a monoexponential function with good reproducibility under controlled laboratory conditions. 99mTc-colloid (TCK17 Cis) compared favorably with 131I-human serum albumin as a tracer and both performed better than colloid gold (198Au). Lymph flowmore » was significantly faster in one pig than in the other. No difference existed between left and right sides or between caudal and rostral sites on each flank, but clearance was significantly slower in thigh than flank skin. Sub-epidermal injections cleared faster and more consistently than either deep or subcutaneous injections. Neither injection volume nor needle tract backflow of tracer influenced results, but local massage significantly enhanced clearance. Escape of 99mTc-colloid by the blood was negligible. These results indicate that skin lymph flow can be reliably measured when conditions are controlled. Extrinsic factors such as massage strongly influence lymph flow. Greater sensitivity in detecting degrees of lymphatic insufficiency may be achieved if a standardized stimulus to lymph flow is administered during isotope clearance measurement.« less

Remote calorimetric detection of urea via flow injection analysis

PubMed Central

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

2017-01-01

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. PMID:26479269

Remote calorimetric detection of urea via flow injection analysis.

PubMed

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.

Ceramic micro-injection molded nozzles for serial femtosecond crystallography sample delivery

NASA Astrophysics Data System (ADS)

Beyerlein, K. R.; Adriano, L.; Heymann, M.; Kirian, R.; Knoška, J.; Wilde, F.; Chapman, H. N.; Bajt, S.

2015-12-01

Serial femtosecond crystallography (SFX) using X-ray Free-Electron Lasers (XFELs) allows for room temperature protein structure determination without evidence of conventional radiation damage. In this method, a liquid suspension of protein microcrystals can be delivered to the X-ray beam in vacuum as a micro-jet, which replenishes the crystals at a rate that exceeds the current XFEL pulse repetition rate. Gas dynamic virtual nozzles produce the required micrometer-sized streams by the focusing action of a coaxial sheath gas and have been shown to be effective for SFX experiments. Here, we describe the design and characterization of such nozzles assembled from ceramic micro-injection molded outer gas-focusing capillaries. Trends of the emitted jet diameter and jet length as a function of supplied liquid and gas flow rates are measured by a fast imaging system. The observed trends are explained by derived relationships considering choked gas flow and liquid flow conservation. Finally, the performance of these nozzles in a SFX experiment is presented, including an analysis of the observed background.

Dynamic interactions between hypersonic vehicle aerodynamics and propulsion system performance

NASA Technical Reports Server (NTRS)

Flandro, G. A.; Roach, R. L.; Buschek, H.

1992-01-01

Described here is the development of a flexible simulation model for scramjet hypersonic propulsion systems. The primary goal is determination of sensitivity of the thrust vector and other system parameters to angle of attack changes of the vehicle. Such information is crucial in design and analysis of control system performance for hypersonic vehicles. The code is also intended to be a key element in carrying out dynamic interaction studies involving the influence of vehicle vibrations on propulsion system/control system coupling and flight stability. Simple models are employed to represent the various processes comprising the propulsion system. A method of characteristics (MOC) approach is used to solve the forebody and external nozzle flow fields. This results in a very fast computational algorithm capable of carrying out the vast number of simulation computations needed in guidance, stability, and control studies. The three-dimensional fore- and aft body (nozzle) geometry is characterized by the centerline profiles as represented by a series of coordinate points and body cross-section curvature. The engine module geometry is represented by an adjustable vertical grid to accommodate variations of the field parameters throughout the inlet and combustor. The scramjet inlet is modeled as a two-dimensional supersonic flow containing adjustable sidewall wedges and multiple fuel injection struts. The inlet geometry including the sidewall wedge angles, the number of injection struts, their sweepback relative to the vehicle reference line, and strut cross-section are user selectable. Combustion is currently represented by a Rayleigh line calculation including corrections for variable gas properties; improved models are being developed for this important element of the propulsion flow field. The program generates (1) variation of thrust magnitude and direction with angle of attack, (2) pitching moment and line of action of the thrust vector, (3) pressure and temperature distributions throughout the system, and (4) performance parameters such as thrust coefficient, specific impulse, mass flow rates, and equivalence ratio. Preliminary results are in good agreement with available performance data for systems resembling the NASP vehicle configuration.

On the feasibility to conduct gradient liquid chromatography separations in narrow-bore columns at pressures up to 2000bar.

PubMed

De Pauw, Ruben; Swier, Tim; Degreef, Bart; Desmet, Gert; Broeckhoven, Ken

2016-11-18

The limits in operating pressures are extended for narrow-bore columns in gradient elution up to 2000bar. As the required pumps for these pressures are incompatible with common chromatographic solvents and are not suitable to apply a mobile phase composition gradient, a mobile phase delivery and injection system is described and experimentally validated which allows to use any possible chromatographic solvent in isocratic and gradient elution. The mobile phase delivery and injection system also allows to perform multiple separations without the need to depressurize the column. This system consists out of 5 dual on/off valves and two large volume loops in which the gradient and equilibration volume of initial mobile phase are loaded by a commercial liquid chromatography pump. The loops are then flushed toward the column at extreme pressures. The mobile phase delivery and injection system is first evaluated in isocratic elution and shows a comparable performance to a state-of-the-art commercial flow-through-needle injector but with twice the pressure rating. Distortion of the loaded gradient by dispersion in the gradient storage loop is studied. The effect of the most important parameters (such as flow rate, pressure and gradient steepness) is experimentally investigated. Different gradient steepnesses and volumes can be applied at different flow rates and operating pressures with a good repeatability. Due to the isobaric operation of the pumps, the gradient is monitored in real-time by a mass flow meter installed at the detector outlet. The chromatograms are then converted from time to volume-base. A separation of a 19-compound sample is performed on a 300×2.1mm column at 1000bar and on a 600×2.1mm column at 2000bar. The peak capacity was found to increase from 141 to 199 and thus scales with L as is predicted by theory. This allows to conclude that the inlet pressure for narrow-bore columns in gradient elution can be increased up to 2000bar without fundamental pressure-induced limitations. Copyright © 2016 Elsevier B.V. All rights reserved.

A reactive transport model for the quantification of risks induced by groundwater heat pump systems in urban aquifers

NASA Astrophysics Data System (ADS)

García-Gil, Alejandro; Epting, Jannis; Ayora, Carlos; Garrido, Eduardo; Vázquez-Suñé, Enric; Huggenberger, Peter; Gimenez, Ana Cristina

2016-11-01

Shallow geothermal resource exploitation through the use of groundwater heat pump systems not only has hydraulic and thermal effects on the environment but also induces physicochemical changes that can compromise the operability of installations. This study focuses on chemical clogging and dissolution subsidence processes observed during the geothermal re-injection of pumped groundwater into an urban aquifer. To explain these phenomena, two transient reactive transport models of a groundwater heat pump installation in an alluvial aquifer were used to reproduce groundwater-solid matrix interactions occurring in a surrounding aquifer environment during system operation. The models couple groundwater flow, heat and solute transport together with chemical reactions. In these models, the permeability distribution in space changes with precipitation-dissolution reactions over time. The simulations allowed us to estimate the calcite precipitation rates and porosity variations over space and time as a function of existent hydraulic gradients in an aquifer as well as the intensity of CO2 exchanges with the atmosphere. The results obtained from the numerical model show how CO2 exolution processes that occur during groundwater reinjection into an aquifer and calcite precipitation are related to hydraulic efficiency losses in exploitation systems. Finally, the performance of reinjection wells was evaluated over time according to different scenarios until the systems were fully obstructed. Our simulations also show a reduction in hydraulic conductivity that forces re-injected water to flow downwards, thereby enhancing the dissolution of evaporitic bedrock and producing subsidence that can ultimately result in a dramatic collapse of the injection well infrastructure.

Effect of double air injection on performance characteristics of centrifugal compressor

NASA Astrophysics Data System (ADS)

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.

Low emission U-fired boiler combustion system

DOEpatents

Ake, Terence; Beittel, Roderick; Lisauskas, Robert A.; Reicker, Eric

2000-01-01

At least one main combustion chamber contains at least one pulverized coal burner. Each pulverized coal burner is operatively arranged for minimizing NO.sub.X production and for maintaining a predetermined operating temperature to liquefy ash within the combustion chamber. The combustion chamber includes a slag drain for removing slag from the combustion chamber. A slag screen is positioned in a generally U-shaped furnace flow pattern. The slag screen is positioned between the combustion chamber and a radiant furnace. The radiant furnace includes a reburning zone for in-furnace No.sub.X reduction. The reburning zone extends between a reburning fuel injection source and at least one overfire air injection port for injecting air.

Micro-channel filling flow considering surface tension effect

NASA Astrophysics Data System (ADS)

Kim, Dong Sung; Lee, Kwang-Cheol; Kwon, Tai Hun; Lee, Seung S.

2002-05-01

Understanding filling flow into micro-channels is important in designing micro-injection molding, micro-fluidic devices and an MIMIC (micromolding in capillaries) process. In this paper, we investigated, both experimentally and numerically, 'transient filling' flow into micro-channels, which differs from steady-state completely 'filled' flow in micro-channels. An experimental flow visualization system was devised to facilitate observation of flow characteristics in filling into micro-channels. Three sets of micro-channels of various widths of different thicknesses (20, 30, and 40 μm) were fabricated using SU-8 on the silicon substrate to find a geometric effect with regard to pressure gradient, viscous force and, in particular, surface tension. A numerical analysis system has also been developed taking into account the surface tension effect with a contact angle concept. Experimental observations indicate that surface tension significantly affects the filling flow to such an extent that even a flow blockage phenomenon was observed at channels of small width and thickness. A numerical analysis system also confirms that the flow blockage phenomenon could take place due to the flow hindrance effect of surface tension, which is consistent with experimental observation. For proper numerical simulations, two correction factors have also been proposed to correct the conventional hydraulic radius for the filling flow in rectangular cross-sectioned channels.

An Interactive Excel Program for Tracking a Single Droplet in Crossflow Computation

NASA Technical Reports Server (NTRS)

Urip, E.; Yang, S. L.; Marek, C. J.

2002-01-01

Spray jet in crossflow has been a subject of research because of its wide application in systems involving pollutant dispersion, jet mixing in the dilution zone of combustors, and fuel injection strategies. The focus of this work is to investigate dispersion of a 2-dimensional atomized spray jet into a 2-dimensional crossflow. A quick computational method is developed using available software. The spreadsheet can be used for any 2D droplet trajectory problem where the drop is injected into the free stream eventually coming to the free stream conditions. During the transverse injection of a spray into high velocity airflow, the droplets (carried along and deflected by a gaseous stream of co-flowing air) are subjected to forces that affect their motion in the flow field. Based on the Newton's Second Law of motion, four ordinary differential equations were used. These equations were then solved by a fourth-order Runge-Kutta method using Excel software. Visual basic programming and Excel macrocode to produce the data facilitate Excel software to plot graphs describing the droplet's motion in the flow field. This program computes and plots the data sequentially without forcing users to open other types of plotting programs. A user's manual on how to use the program is also included in this report.

A novel stopped flow injection-amperometric procedure for the determination of chlorate.

PubMed

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.

Flow injection analysis of picric acid explosive using a copper electrode as electrochemical detector.

PubMed

Junqueira, João R C; de Araujo, William R; Salles, Maiara O; Paixão, Thiago R L C

2013-01-30

A simple and fast electrochemical method for quantitative analysis of picric acid explosive (nitro-explosive) based on its electrochemical reduction at copper surfaces is reported. To achieve a higher sample throughput, the electrochemical sensor was adapted in a flow injection system. Under optimal experimental conditions, the peak current response increases linearly with picric acid concentration over the range of 20-300 μmol L(-1). The repeatability of the electrode response in the flow injection analysis (FIA) configuration was evaluated as 3% (n=10), and the detection limit of the method was estimated to be 6.0 μmol L(-1) (S/N=3). The sample throughput under optimised conditions was estimated to be 550 samples h(-1). Peroxide explosives like triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD) were tested as potential interfering substances for the proposed method, and no significant interference by these explosives was noticed. The proposed method has interesting analytical parameters, environmental applications, and low cost compared with other electroanalytical methods that have been reported for the quantification of picric acid. Additionally, the possibility to develop an in situ device for the detection of picric acid using a disposable sensor was evaluated. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Simple flow injection for determination of sulfite by amperometric detection using glassy carbon electrode modified with carbon nanotubes-PDDA-gold nanoparticles.

PubMed

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.

Experiment T001: Entry communication on the Gemini 3 mission

NASA Technical Reports Server (NTRS)

Schroeder, L. C.; Sims, T. E.; Cuddihy, W. F.

1971-01-01

Water addition to the Gemini 3 exhaust plasma was studied to determine its effectiveness in the establishment of communication links during the entry portion of the flight. Attenuation levels were measured with and without water injection at uhf frequencies of 230.4 and 296.8 megahertz and at the C-band frequency of 5690 megahertz. Ultrahigh frequency signals that had been blacked out were restored to significant levels, during early portions of the water-injection sequence, by the high flow rate injection. The C-band signal was enhanced by medium and high flow rate injections during the latter portion of the injection period. The uhf signal recovered during water injection resulted in an antenna pattern that was beamed in the radial direction of injection from the spacecraft. Postflight analysis showed that the uhf recovery data were consistent with injection-penetration theory.

Understanding leachate flow in municipal solid waste landfills by combining time-lapse ERT and subsurface flow modelling - Part II: Constraint methodology of hydrodynamic models.

PubMed

Audebert, M; Oxarango, L; Duquennoi, C; Touze-Foltz, N; Forquet, N; Clément, R

2016-09-01

Leachate recirculation is a key process in the operation of municipal solid waste landfills as bioreactors. To ensure optimal water content distribution, bioreactor operators need tools to design leachate injection systems. Prediction of leachate flow by subsurface flow modelling could provide useful information for the design of such systems. However, hydrodynamic models require additional data to constrain them and to assess hydrodynamic parameters. Electrical resistivity tomography (ERT) is a suitable method to study leachate infiltration at the landfill scale. It can provide spatially distributed information which is useful for constraining hydrodynamic models. However, this geophysical method does not allow ERT users to directly measure water content in waste. The MICS (multiple inversions and clustering strategy) methodology was proposed to delineate the infiltration area precisely during time-lapse ERT survey in order to avoid the use of empirical petrophysical relationships, which are not adapted to a heterogeneous medium such as waste. The infiltration shapes and hydrodynamic information extracted with MICS were used to constrain hydrodynamic models in assessing parameters. The constraint methodology developed in this paper was tested on two hydrodynamic models: an equilibrium model where, flow within the waste medium is estimated using a single continuum approach and a non-equilibrium model where flow is estimated using a dual continuum approach. The latter represents leachate flows into fractures. Finally, this methodology provides insight to identify the advantages and limitations of hydrodynamic models. Furthermore, we suggest an explanation for the large volume detected by MICS when a small volume of leachate is injected. Copyright © 2016 Elsevier Ltd. All rights reserved.

Automated system for on-line determination of dimethylarsinic and inorganic arsenic by hydride generation-atomic fluorescence spectrometry.

PubMed

Chaparro, L L; Ferrer, L; Cerdà, V; Leal, L O

2012-09-01

A multisyringe flow-injection approach has been coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS) with UV photo-oxidation for dimethylarsinic (DMA), inorganic As and total As determination, depending on the pre-treatment given to the sample (extraction or digestion). The implementation of a UV lamp allows on-line photo-oxidation of DMA and the following arsenic detection, whereas a bypass leads the flow directly to the HG-AFS system, performing inorganic arsenic determination. DMA concentration is calculated by the difference of total inorganic arsenic and measurement of the photo-oxidation step. The detection limits for DMA and inorganic arsenic were 0.09 and 0.47 μg L(-1), respectively. The repeatability values accomplished were of 2.4 and 1.8%, whereas the injection frequencies were 24 and 28 injections per hour for DMA and inorganic arsenic, respectively. This method was validated by means of a solid reference material BCR-627 (muscle of tuna) with good agreement with the certified values. Satisfactory results for DMA and inorganic arsenic determination were obtained in several water matrices. The proposed method offers several advantages, such as increasing the sampling frequency, low detection limits and decreasing reagents and sample consumption, which leads to lower waste generation.

Rhodamine-WT dye losses in a mountain stream environment

USGS Publications Warehouse

Bencala, Kenneth E.; Rathburn, Ronald E.; Jackman, Alan P.; Kennedy, Vance C.; Zellweger, Gary W.; Avanzino, Ronald J.

1983-01-01

A significant fraction of rhodamine WT dye was lost during a short term multitracer injection experiment in a mountain stream environment. The conservative anion chloride and the sorbing cation lithium were concurrently injected. In-stream rhodamine WT concentrations were as low as 45 percent of that expected, based on chloride data. Concentration data were available from shallow‘wells’dug near the stream course and from a seep of suspected return flow. Both rhodamine WT dye and lithium were nonconservative with respect to the conservative chloride, with rhodamine WT dye closely following the behavior of the sorbing lithium.Nonsorption and sorption mechanisms for rhodamine WT loss in a mountain stream were evaluated in laboratory experiments. Experiments evaluating nonsorption losses indicated minimal losses by such mechanisms. Laboratory experiments using sand and gravel size streambed sediments show an appreciable capacity for rhodamine WT sorption.The detection of tracers in the shallow wells and seep indicates interaction between the stream and the flow in the surrounding subsurface, intergravel water, system. The injected tracers had ample opportunity for intimate contact with materials shown in the laboratory experiments to be potentially sorptive. It is suggested that in the study stream system, interaction with streambed gravel was a significant mechanism for the attenuation of rhodamine WT dye (relative to chloride).

Split Flow Online Solid-Phase Extraction Coupled with Inductively Coupled Plasma Mass Spectrometry System for One-Shot Data Acquisition of Quantification and Recovery Efficiency.

PubMed

Furukawa, Makoto; Takagai, Yoshitaka

2016-10-04

Online solid-phase extraction (SPE) coupled with inductively coupled plasma mass spectrometry (ICPMS) is a useful tool in automatic sequential analysis. However, it cannot simultaneously quantify the analytical targets and their recovery percentages (R%) in one-shot samples. We propose a system that simultaneously acquires both data in a single sample injection. The main flowline of the online solid-phase extraction is divided into main and split flows. The split flow line (i.e., bypass line), which circumvents the SPE column, was placed on the main flow line. Under program-controlled switching of the automatic valve, the ICPMS sequentially measures the targets in a sample before and after column preconcentration and determines the target concentrations and the R% on the SPE column. This paper describes the system development and two demonstrations to exhibit the analytical significance, i.e., the ultratrace amounts of radioactive strontium ( 90 Sr) using commercial Sr-trap resin and multielement adsorbability on the SPE column. This system is applicable to other flow analyses and detectors in online solid phase extraction.

Water injected fuel cell system compressor

DOEpatents

Siepierski, James S.; Moore, Barbara S.; Hoch, Martin Monroe

2001-01-01

A fuel cell system including a dry compressor for pressurizing air supplied to the cathode side of the fuel cell. An injector sprays a controlled amount of water on to the compressor's rotor(s) to improve the energy efficiency of the compressor. The amount of water sprayed out the rotor(s) is controlled relative to the mass flow rate of air inputted to the compressor.

Experimental determination of sorption in fractured flow systems

NASA Astrophysics Data System (ADS)

Zimmerman, Mitchell D.; Bennett, Philip C.; Sharp, John M.; Choi, Wan-Joo

2002-09-01

Fracture "skins" are alteration zones on fracture surfaces created by a variety of biological, chemical, and physical processes. Skins increase surface area, where sorption occurs, compared to the unaltered rock matrix. This study examines the sorption of organic solutes on altered fracture surfaces in an experimental fracture-flow apparatus. Fracture skins containing abundant metal oxides, clays, and organic material from the Breathitt Formation (Kentucky, USA) were collected in a manner such that skin surface integrity was maintained. The samples were reassembled in the lab in a flow-through apparatus that simulated ˜2.7 m of a linear fracture "conduit." A dual-tracer injection scheme was utilized with the sorbing or reactive tracer compared to a non-reactive tracer (chloride) injected simultaneously. Sorption was assessed from the ratio of the first temporal moments of the breakthrough curves and from the loss of reactive tracer mass and evaluated as a function of flow velocity and solute type. The breakthrough curves suggest dual-flow regimes in the fracture with both sorbing and non-sorbing flow fields. Significant sorption occurs for the reactive components, and sorption increased with decreasing flow rate and decreasing compound solubility. Based on moment analysis, however, there was little retardation of the center of solute mass. These data suggest that non-equilibrium sorption processes dominate and that slow desorption and boundary layer diffusion cause extensive tailing in the breakthrough curves.

Optimization of Dendritic Cell-Mediated Cytotoxic T-Cell Activation by Tracking of Dendritic Cell Migration Using Reporter Gene Imaging.

PubMed

Lee, Hongje; Lee, Ho Won; La Lee, You; Jeon, Yong Hyun; Jeong, Shin Young; Lee, Sang-Woo; Lee, Jaetae; Ahn, Byeong-Cheol

2018-06-01

The aim of this study is to optimize the dendritic cell (DC)-mediated T-cell activation using reporter gene imaging and flow cytometric analysis in living mice. A murine dendritic cell line (DC2.4) co-expressing effluc and Thy1.1 genes were established by transfection with retroviral vectors. Thy1.1 positive cells were sorted by magnetic bead separation system (DC2.4/effluc). Cell proliferation assay and phenotype analysis to determine the effects of gene transduction on the function of dendritic cells between parental DC2.4 and DC2.4/effluc were performed. To optimize the DC-mediated immune response by cell number or frequency, different cell numbers (5 × 10 5 , 1 × 10 6 , and 2 × 10 6  DC2.4/effluc) or different frequencies of DC2.4/effluc (first, second, and third injections) were injected in the right footpad of mice. The migration of the DC2.4/effluc into the draining popliteal lymph node of mice was monitored by bioluminescence imaging (BLI). Flow cytometric analysis was performed with splenocytes to determine the cytotoxic T-cell population after injection of DC2.4/effluc. Parental DC2.4 and DC2.4/effluc exhibit no significant differences in their proliferation and phenotype. BLI signals were observed in the draining popliteal lymph node at day 1 after injection of DC2.4/effluc in 1 × 10 6 and 2 × 10 6 cells-injected groups. The highest BLI signal intensity was detected in 2 × 10 6 cells-injected mice. On day 11, the BLI signal was detected in only 2 × 10 6 cell-injected group but not in other groups. Optimized cell numbers (2 × 10 6 ) were injected in three animal groups with a different frequency (first, second, and third injection groups). The BLI signal was detected at day 1 and maintained until day 7 in the first injection group, but there is low signal intensity in the second and the third injection groups. Although the expression levels of Thy1.1 gene in the first injection group were very high, there reveals no expression of Thy1.1 gene in the second and the third injection groups. The number of tumor-specific CD8 + T-cells in the spleen significantly increased, as the number of DC injections increases. Successful optimization of DC-mediated cytotoxic T-cell activation in living mice using reporter gene imaging and flow cytometric analysis was achieved. The optimization of DC-mediated cytotoxic T-cell activation could be applied for the future DC-based immunotherapy.

Eruption and emplacement dynamics of a thick trachytic lava flow of the Sancy volcano (France)

NASA Astrophysics Data System (ADS)

Latutrie, Benjamin; Harris, Andrew; Médard, Etienne; Gurioli, Lucia

2017-01-01

A 70-m-thick, 2200-m-long (51 × 106 m3) trachytic lava flow unit underlies the Puy de Cliergue (Mt. Dore, France). Excellent exposure along a 400-m-long and 60- to 85-m-high section allows the flow interior to be accessed on two sides of a glacial valley that cuts through the unit. We completed an integrated morphological, structural, textural, and chemical analysis of the unit to gain insights into eruption and flow processes during emplacement of this thick silicic lava flow, so as to elucidate the chamber and flow dynamic processed that operate during the emplacement of such systems. The unit is characterized by an inverse chemical stratification, where there is primitive lava beneath the evolved lava. The interior is plug dominated with a thin basal shear zone overlying a thick basal breccia, with ramping affecting the entire flow thickness. To understand these characteristics, we propose an eruption model that first involves processes operating in the magma chamber whereby a primitive melt is injected into an evolved magma to create a mixed zone at the chamber base. The eruption triggered by this event first emplaced a trachytic dome, into which banded lava from the chamber base was injected. Subsequent endogenous dome growth led to flow down the shallow slope to the east on which the highly viscous (1012 Pa s) coulée was emplaced. The flow likely moved extremely slowly, being emplaced over a period of 4-10 years in a glacial manner, where a thick (>60-m) plug slid over a thin (5-m-thick) basal shear zone. Excellent exposure means that the Puy de Cliergue complex can be viewed as a case type location for understanding and defining the eruption and emplacement of thick, high-viscosity, silicic lava flow systems.

Re-injection feasibility study of fracturing flow-back fluid in shale gas mining

NASA Astrophysics Data System (ADS)

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.

Calculation of eddy viscosity in a compressible turbulent boundary layer with mass injection and chemical reaction, volume 1. [theoretical analysis

NASA Technical Reports Server (NTRS)

Omori, S.

1973-01-01

The turbulent kinetic energy equation is coupled with boundary layer equations to solve the characteristics of compressible turbulent boundary layers with mass injection and combustion. The Reynolds stress is related to the turbulent kinetic energy using the Prandtl-Wieghardt formulation. When a lean mixture of hydrogen and nitrogen is injected through a porous plate into the subsonic turbulent boundary layer of air flow and ignited by external means, the turbulent kinetic energy increases twice as much as that of noncombusting flow with the same mass injection rate of nitrogen. The magnitudes of eddy viscosity between combusting and noncombusting flows with injection, however, are almost the same due to temperature effects, while the distributions are different. The velocity profiles are significantly affected by combustion; that is, combustion alters the velocity profile as if the mass injection rate is increased, reducing the skin-friction as a result of a smaller velocity gradient at the wall. If pure hydrogen as a transpiration coolant is injected into a rocket nozzle boundary layer flow of combustion products, the temperature drops significantly across the boundary layer due to the high heat capacity of hydrogen. At a certain distance from the wall, hydrogen reacts with the combustion products, liberating an extensive amount of heat. The resulting large increase in temperature reduces the eddy viscosity in this region.

Recovery of injected freshwater to differentiate fracture flow in a low-permeability brackish aquifer

NASA Astrophysics Data System (ADS)

Miotliński, Konrad; Dillon, Peter J.; Pavelic, Paul; Cook, Peter G.; Page, Declan W.; Levett, Kerry

2011-10-01

SummaryA low-permeability weathered siltstone-sandstone aquifer containing brackish water was investigated to measure recoverability of injected freshwater with the aim of determining the significance of secondary porosity in contributing to groundwater flow and transport. Examination of the core, borehole geophysics, Radon-222, electromagnetic flowmeter (EMF) profiles and step-drawdown pumping tests did not identify whether fractures contribute to groundwater flow. A number of injection and recovery tests lasting from 3 days to 3 months using potable water showed a large degree of mixing with native groundwater. Withdrawal greater than 12-17% of the injected volume resulted in recovered water containing more native groundwater than injected water. A finite element solute transport model was set up to reproduce the observed salinity in recovered water. Without the inclusion of discrete fractures in the model it was not possible to get a fit between the observed and modelled salinity of recovered water within a realistic range of dispersivity values. The model was subsequently verified by using data from long-term injection and recovery trials. This evaluation of mixing conclusively demonstrated that the aquifer behaved as a fractured rock aquifer and not as an aquifer with primary porosity alone. Therefore, aquifer storage and recovery can be a very useful hydrogeological method to identify the occurrence of fracture flow in aquifers where there is a measurable concentration difference between the injected water and ambient groundwater.

Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

NASA Astrophysics Data System (ADS)

Shams, Bilal; Yao, Jun; Zhang, Kai; Zhang, Lei

2017-08-01

Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulation-condensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources. In gas injection, the flooding pattern, injection timing and injection duration are key parameters to study an efficient EOR scenario in order to recover lost condensate. This work contains sensitivity analysis on different parameters to generate an accurate investigation about the effects on performance of different injection scenarios in homogeneous gas condensate system. In this paper, starting time of gas cycling and injection period are the parameters used to influence condensate recovery of a five-spot well pattern which has an injection pressure constraint of 3000 psi and production wells are constraint at 500 psi min. BHP. Starting injection times of 1 month, 4 months and 9 months after natural depletion areapplied in the first study. The second study is conducted by varying injection duration. Three durations are selected: 100 days, 400 days and 900 days. In miscible gas injection, miscibility and vaporization of condensate by injected gas is more efficient mechanism for condensate recovery. From this study, it is proven that the application of gas cycling on five-spot well pattern greatly enhances condensate recovery preventing financial, economic and resource loss that previously occurred.

Central venous catheter integrity during mechanical power injection of iodinated contrast medium.

PubMed

Macha, Douglas B; Nelson, Rendon C; Howle, Laurens E; Hollingsworth, John W; Schindera, Sebastian T

2009-12-01

To evaluate a widely used nontunneled triple-lumen central venous catheter in order to determine whether the largest of the three lumina (16 gauge) can tolerate high flow rates, such as those required for computed tomographic angiography. Forty-two catheters were tested in vitro, including 10 new and 32 used catheters (median indwelling time, 5 days). Injection pressures were continuously monitored at the site of the 16-gauge central venous catheter hub. Catheters were injected with 300 and 370 mg of iodine per milliliter of iopamidol by using a mechanical injector at increasing flow rates until the catheter failed. The infusion rate, hub pressure, and location were documented for each failure event. The catheter pressures generated during hand injection by five operators were also analyzed. Mean flow rates and pressures at failure were compared by means of two-tailed Student t test, with differences considered significant at P < .05. Injections of iopamidol with 370 mg of iodine per milliliter generate more pressure than injections of iopamidol with 300 mg of iodine per milliliter at the same injection rate. All catheters failed in the tubing external to the patient. The lowest flow rate at which catheter failure occurred was 9 mL/sec. The lowest hub pressure at failure was 262 pounds per square inch gauge (psig) for new and 213 psig for used catheters. Hand injection of iopamidol with 300 mg of iodine per milliliter generated peak hub pressures ranging from 35 to 72 psig, corresponding to flow rates ranging from 2.5 to 5.0 mL/sec. Indwelling use has an effect on catheter material property, but even for used catheters there is a substantial safety margin for power injection with the particular triple-lumen central venous catheter tested in this study, as the manufacturer's recommendation for maximum pressure is 15 psig.

Engineering solutions to improve the removal of fecal indicator bacteria by bioinfiltration systems during intermittent flow of stormwater.

PubMed

Mohanty, Sanjay K; Torkelson, Andrew A; Dodd, Hanna; Nelson, Kara L; Boehm, Alexandria B

2013-10-01

Bioinfiltration systems facilitate the infiltration of urban stormwater into soil and reduce high flow events and flooding. Stormwater carries a myriad of pollutants including fecal indicator bacteria (FIB). Significant knowledge gaps exist about the ability of bioinfiltration systems to remove and retain FIB. The present study investigates the ability of model, simplified bioinfiltration systems containing quartz sand and iron oxide-coated quartz sand (IOCS) to remove two FIB (Enterococcus faecalis and Escherichia coli) suspended in synthetic stormwater with and without natural organic matter (NOM) as well as the potential for accumulated FIB to be remobilized during intermittent flow. The experiments were conducted in two phases: (1) the saturated columns packed with either sand or IOCS were contaminated by injecting stormwater with bacteria followed by injection of sterile stormwater and (2) the contaminated columns were subjected to intermittent infiltration of sterile stormwater preceded by a pause during which columns were either kept saturated or drained by gravity. During intermittent flow, fewer bacteria were released from the saturated column compared to the column drained by gravity: 12% of attached E. coli and 3% of attached Ent. faecalis were mobilized from the drained sand column compared to 3% of attached E. coli and 2% attached Ent. faecalis mobilized from the saturated sand column. Dry and wet cycles introduce moving air-water interfaces that can scour bacteria from grain surfaces. During intermittent flows, less than 0.2% of attached bacteria were mobilized from IOCS, which bound both bacteria irreversibly in the absence of NOM. Addition of NOM, however, increased bacterial mobilization from IOCS: 50% of attached E. coli and 8% of attached Ent. faecalis were released from IOCS columns during draining and rewetting. Results indicate that using geomedia such as IOCS that promote irreversible attachment of bacteria, and maintaining saturated condition, could minimize the mobilization of previous attached bacteria from bioinfiltration systems, although NOM may significantly decrease these benefits.

Influence of gas injection on viscous and viscoelastic properties of Xanthan gum.

PubMed

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.

Automated Flow-Injection Instrument for Chemiluminescence Detection Using a Low-Cost Photodiode Detector

ERIC Educational Resources Information Center

Economou, A.; Papargyris, D.; Stratis, J.

2004-01-01

The development of an FI analyzer for chemiluminescence detection using a low-cost photoiodide is presented. The experiment clearly demonstrates in a single interdisciplinary project the way in which different aspects in chemical instrumentation fit together to produce a working analytical system.

Assessment of hydrogeologic conditions with emphasis on water quality and wastewater injection, southwest Sarasota and West Charlotte counties, Florida

USGS Publications Warehouse

Hutchinson, C.B.

1992-01-01

The 250-square-mile area of southwest Sarasota and west Charlotte Counties is underlain by a complex hydrogeologic system having diverse ground-water quality. The surficial and intermediate aquifer systems and the Upper Floridan aquifer of the Floridan aquifer system contain six separate aquifers, or permeable zones, and have a total thickness of about 2,000 feet. Water in the clastic surficial aquifer system is potable and is tapped by hundreds of shallow, low-yielding supply wells. Water in the mixed clastic and carbonate intermediate aquifer system is potable in the upper part, but in the lower part, because of increasing salinity, it is used primarily for reverse-osmosis desalinization feed water and irrigation. Within the Upper Floridan aquifer, limestone and dolomite of the Suwannee permeable zone are tapped by irrigation and reverse-osmosis supply wells. The underlying, less permeable limestone of the Suwannee-Ocala semiconfining unit generally encompasses the transition zone between freshwater and very saline water. Interbedded limestone and dolomite of the Ocala-Avon Park moderately permeable zone and Avon Park highly permeable zone compose the deep, very saline injection zone. Potential ground-water contamination problems include flooding by storm tides, upward movement of saline water toward pumping centers by natural and induced leakage or through improperly constructed and abandoned wells, and lateral and vertical movement of treated sewage and reverse-osmosis wastewater injected into deep zones. Effects of flooding are evident in coastal areas where vertical layering of fresh and saline waters is observed. Approximately 100 uncontrolled flowing artesian wells that have interaquifer flow rates as high as 350 gallons per minute have been located and scheduled for plugging by the Southwest Florida Water Management District--in an attempt to improve ground-water quality of the shallow aquifers. Because each aquifer or permeable zone has unique head and water-quality characteristics, construction of single-zone wells would eliminate cross-contamination and borehole interflow. Such a program, when combined with the plugging of shallow-cased wells having long open-hole intervals connecting multiple zones, would safeguard ground-water resources in the study area. The study area encompasses seven wastewater injection sites that have a projected capacity for injecting 29 million gallons per day into the zone 1,100 to 2,050 feet below land surface. There are six additional sites within 20 miles. The first well began injecting reverse-osmosis wastewater in 1984, and since then, other wells have been drilled and permitted for injection of treated sewage. A numerical model was used to evaluate injection-well design and potential for movement of injected wastewater within the hydrogeologic framework. The numerical model was used to simulate injection through a representative well at a rate of 1 million gallons per day for 10 years. In this simulation, a convection cell developed around the injection well with the buoyant fresh injectant rising to form a lens within the injection zone below the lower Suwannee-Ocala semiconfining unit. Around an ideal, fully penetrating well cased 50 feet into the injection zone and open from a depth of 1,150 feet to 2,050 feet, simulations show that the injectant moves upward to a depth of 940 feet, forms a lens about 600 feet thick, and spreads radially outward to a distance of about 2,300 feet after 10 years. Comparison simulations of injection through wells having open depth intervals of 1,150 to 1,400 feet and 1,450 to 2,050 feet demonstrate that such changes in well construction have little effect on the areal spread of the injectant lens or the rate of upward movement. Simulations also indicate that reverse-osmosis wastewater injected beneath a supply well field, where water levels above the semiconfining unit are lowered 20 feet by pumping, would move upward after 10 years to a de

Multicapillary Gas Chromatography-Temperature Modulated Metal Oxide Semiconductor Sensors Array Detector for Monitoring of Volatile Organic Compounds in Closed Atmosphere Using Gaussian Apodization Factor Analysis.

PubMed

Alinoori, Amir Hossein; Masoum, Saeed

2018-05-22

A unique metal oxide semiconductor sensor (MOS) array detector with eight sensors was designed and fabricated in a PTFE chamber as an interface for coupling with multicapillary gas chromatography. This design consists of eight transfer lines with equal length between the multicapillary columns (MCC) and sensors. The deactivated capillary columns were passed through each transfer line and homemade flow splitter to distribute the same gas flow on each sensor. Using the eight ports flow splitter design helps us to equal the length of carrier gas path and flow for each sensor, minimizing the dead volume of the sensor's chamber and increasing chromatographic resolution. In addition to coupling of MCC to MOS array detector and other considerations in hardware design, modulation of MOS temperature was used to increase sensitivity and selectivity, and data analysis was enhanced with adapted Gaussian apodization factor analysis (GAFA) as a multivariate curve resolution algorithm. Continues air sampling and injecting system (CASI) design provides a fast and easily applied method for continues injection of air sample with no additional sample preparation. The analysis cycle time required for each run is less than 300 s. The high sample load and sharp injection with the fast separation by MCC decrease the peak widths and improve detection limits. This homemade customized instrument is an alternative to other time-consuming and expensive technologies for continuous monitoring of outgassing in air samples.

Generating A Strobed Laser Light Sheet

NASA Technical Reports Server (NTRS)

Leighty, Bradley D.; Franke, John M.; Rhodes, David B.; Jones, Stephen B.

1994-01-01

An optoelectronic system generating synchronous, strobed sheet of laser light developed for use in making visible flow of air about model helicopter rotor. Used in wind-tunnel tests to determine actual locations of vortices for comparison with locations predicted by mathematical models to validate models. Each blade tip produces vortex. By establishing successive vortex locations, researcher determines trajectory of vortex pattern. Light-sheet strobe circuits provide selection of blade positions, strobe-pulse durations, and multiple pulses per revolution for rotors having two to nine blades. To make flow visible, vaporizing propylene glycol injected upstream of model. System also provides calibrated trigger delay of strobe pulses, adjustable strobe-pulse durations, selectable number of blades, and slip-sync mode to make flow visible as though in slow motion.

Bacterial lipopolysaccharide-induced systemic inflammation alters perfusion of white matter-rich regions without altering flow in brain-irrigating arteries: Relationship to blood-brain barrier breakdown?

PubMed

Dhaya, Ibtihel; Griton, Marion; Raffard, Gérard; Amri, Mohamed; Hiba, Bassem; Konsman, Jan Pieter

2018-01-15

To better understand brain dysfunction during sepsis, cerebral arterial blood flow was assessed with Phase Contrast Magnetic Resonance Imaging, perfusion with Arterial Spin Labeling and structure with diffusion-weighted Magnetic Resonance Imaging in rats after intraperitoneal administration of bacterial lipopolysaccharides. Although cerebral arterial flow was not altered, perfusion of the corpus callosum region and diffusion parallel to its fibers were higher after lipopolysaccharide administration as compared to saline injection. In parallel, lipopolysaccharide induced perivascular immunoglobulin-immunoreactivity in white matter. These findings indicate that systemic inflammation can result in increased perfusion, blood-brain barrier breakdown and altered water diffusion in white matter. Copyright © 2017 Elsevier B.V. All rights reserved.

Three-dimensional numerical reservoir simulation of the EGS Demonstration Project at The Geysers geothermal field

NASA Astrophysics Data System (ADS)

Borgia, Andrea; Rutqvist, Jonny; Oldenburg, Curt M.; Hutchings, Lawrence; Garcia, Julio; Walters, Mark; Hartline, Craig; Jeanne, Pierre; Dobson, Patrick; Boyle, Katie

2013-04-01

The Enhanced Geothermal System (EGS) Demonstration Project, currently underway at the Northwest Geysers, California, aims to demonstrate the feasibility of stimulating a deep high-temperature reservoir (up to 400 °C) through water injection over a 2-year period. On October 6, 2011, injection of 25 l/s started from the Prati 32 well at a depth interval of 1850-2699 m below sea level. After a period of almost 2 months, the injection rate was raised to 63 l/s. The flow rate was then decreased to 44 l/s after an additional 3.5 months and maintained at 25 l/s up to August 20, 2012. Significant well-head pressure changes were recorded at Prati State 31 well, which is separated from Prati 32 by about 500 m at reservoir level. More subdued pressure increases occur at greater distances. The water injection caused induced seismicity in the reservoir in the vicinity of the well. Microseismic monitoring and interpretation shows that the cloud of seismic events is mainly located in the granitic intrusion below the injection zone, forming a cluster elongated SSE-NNW (azimuth 170°) that dips steeply to the west. In general, the magnitude of the events increases with depth and the hypocenter depth increases with time. This seismic cloud is hypothesized to correlate with enhanced permeability in the high-temperature reservoir and its variation with time. Based on the existing borehole data, we use the GMS™ GUI to construct a realistic three-dimensional (3D) geologic model of the Northwest Geysers geothermal field. This model includes, from the top down, a low permeability graywacke layer that forms the caprock for the reservoir, an isothermal steam zone (known as the normal temperature reservoir) within metagraywacke, a hornfels zone (where the high-temperature reservoir is located), and a felsite layer that is assumed to extend downward to the magmatic heat source. We then map this model onto a rectangular grid for use with the TOUGH2 multiphase, multicomponent, non-isothermal porous media numerical flow simulator in order to model the evolution and injection-related operational dynamics of The Geysers geothermal field. At the bottom of the domain in the felsite, we impose a constant temperature, constant saturation, low-permeability boundary. Laterally we set no-flow boundaries (no mass or heat flow), while at the top we use a fully aqueous-phase-saturated constant atmospheric pressure boundary condition. We compute initial conditions for two different conceptual models. The first conceptual model has two phases (gas and aqueous) with decreasing proportions of gas from the steam zone downward; the second model has dry steam all the way from the steam zone to the bottom. The first may be more similar to a pre-exploitation condition, before production reduced pressure and dried out the system, while the second is calibrated to the pressure and temperature actually measured in the reservoir today. Our preliminary results are in reasonable agreement with the pressure monitoring at Prati State 31. These results will be used in hydrogeomechanical modeling to plan, design, and validate the effects of injection in the system.

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.

PubMed

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.

Pressurized feed-injection spray-forming apparatus

DOEpatents

Berry, R.A.; Fincke, J.R.; McHugh, K.M.

1995-08-29

A spray apparatus and method are disclosed for injecting a heated, pressurized liquid in a first predetermined direction into a pressurized gas flow that is flowing in a second predetermined direction, to provide for atomizing and admixing the liquid with the gas to form a two-phase mixture. A valve is also disposed within the injected liquid conduit to provide for a pulsed injection of the liquid and timed deposit of the atomized gas phase. Preferred embodiments include multiple liquid feed ports and reservoirs to provide for multiphase mixtures of metals, ceramics, and polymers. 22 figs.

Pressurized feed-injection spray-forming apparatus

DOEpatents

Berry, Ray A.; Fincke, James R.; McHugh, Kevin M.

1995-01-01

A spray apparatus and method for injecting a heated, pressurized liquid in a first predetermined direction into a pressurized gas flow that is flowing in a second predetermined direction, to provide for atomizing and admixing the liquid with the gas to form a two-phase mixture. A valve is also disposed within the injected liquid conduit to provide for a pulsed injection of the liquid and timed deposit of the atomized gas phase. Preferred embodiments include multiple liquid feed ports and reservoirs to provide for multiphase mixtures of metals, ceramics, and polymers.

Development of the T+M coupled flow–geomechanical simulator to describe fracture propagation and coupled flow–thermal–geomechanical processes in tight/shale gas systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jihoon; Moridis, George J.

2013-10-01

We developed a hydraulic fracturing simulator by coupling a flow simulator to a geomechanics code, namely T+M simulator. Modeling of the vertical fracture development involves continuous updating of the boundary conditions and of the data connectivity, based on the finite element method for geomechanics. The T+M simulator can model the initial fracture development during the hydraulic fracturing operations, after which the domain description changes from single continuum to double or multiple continua in order to rigorously model both flow and geomechanics for fracture-rock matrix systems. The T+H simulator provides two-way coupling between fluid-heat flow and geomechanics, accounting for thermoporomechanics, treatsmore » nonlinear permeability and geomechanical moduli explicitly, and dynamically tracks changes in the fracture(s) and in the pore volume. We also fully accounts for leak-off in all directions during hydraulic fracturing. We first validate the T+M simulator, matching numerical solutions with the analytical solutions for poromechanical effects, static fractures, and fracture propagations. Then, from numerical simulation of various cases of the planar fracture propagation, shear failure can limit the vertical fracture propagation of tensile failure, because of leak-off into the reservoirs. Slow injection causes more leak-off, compared with fast injection, when the same amount of fluid is injected. Changes in initial total stress and contributions of shear effective stress to tensile failure can also affect formation of the fractured areas, and the geomechanical responses are still well-posed.« less

Biosensor Based on Self-Assembling Acetylcholinesterase on Carbon Nanotubes for Flow injection/Amperometric Detection of Organophosphate Pesticides and Nerve Agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guodong; Lin, Yuehe

A highly sensitive flow-injection amperometric biosensor for organophosphate pesticides and nerve agents based on self-assembly of acetylcholinesterase (AChE) on carbon nanotube (CNT)-modified glassy carbon (GC) electrode is described. AChE is immobilized on the negatively-charged CNT surface by alternatively assembling a cationic polydiallyldimethylammonium chloride (PDDA) layer and an AChE layer. Transmission electron microscopy images confirm the formation of layer-by-layer nanostructures on carboxyl functionalized CNTs. The unique sandwich-like structure (PDDA/AChE/PDDA) on the CNT surface formed by self-assembly provides a favorable microenvironment to keep the bioactivity of AChE and to prevent enzyme molecule leakage. The electrocatalytic activity of CNT leads to a greatlymore » improved electrochemical detection of the enzymatically generated thiocholine product, including a low oxidation overvoltage (+150 mV), higher sensitivity, and stability. The developed PDDA/AChE/PDDA/CNT/GC biosensor integrated into a flow injection system was used to monitor organophosphate pesticides and nerve agents, such as paraoxon. The sensor performance, including inhibition time and regeneration conditions, was optimized with respect to operating conditions. Under the optimal conditions, the biosensor was used to measure as low as 0.4 pM paraoxon with a 6-min inhibition time. The biosensor had excellent operational lifetime stability with no decrease in the activity of enzymes for more than 20 repeated measurements over a 1-week period. The developed biosensor system is an ideal tool for online monitoring of organophosphate pesticides and nerve agents.« less

Investigations into the application of a combination of bioventing and biotrickling filter technologies for soil decontamination processes--a transition regime between bioventing and soil vapour extraction.

PubMed

Magalhães, S M C; Ferreira Jorge, R M; Castro, P M L

2009-10-30

Bioventing has emerged as one of the most cost-effective in situ technologies available to address petroleum light-hydrocarbon spills, one of the most common sources of soil pollution. However, the major drawback associated with this technology is the extended treatment time often required. The present study aimed to illustrate how an intended air-injection bioventing technology can be transformed into a soil vapour extraction effort when the air flow rates are pushed to a stripping mode, thus leading to the treatment of the off-gas resulting from volatilisation. As such, a combination of an air-injection bioventing system and a biotrickling filter was applied for the treatment of contaminated soil, the latter aiming at the treatment of the emissions resulting from the bioventing process. With a moisture content of 10%, soil contaminated with toluene at two different concentrations, namely 2 and 14 mg g soil(-1), were treated successfully using an air-injection bioventing system at a constant air flow rate of ca. 0.13 dm(3) min(-1), which led to the removal of ca. 99% toluene, after a period of ca. 5 days of treatment. A biotrickling filter was simultaneously used to treat the outlet gas emissions, which presented average removal efficiencies of ca. 86%. The proposed combination of biotechnologies proved to be an efficient solution for the decontamination process, when an excessive air flow rate was applied, reducing both the soil contamination and the outlet gas emissions, whilst being able to reduce the treatment time required by bioventing only.

Voltage stability index based optimal placement of static VAR compensator and sizing using Cuckoo search algorithm

NASA Astrophysics Data System (ADS)

Venkateswara Rao, B.; Kumar, G. V. Nagesh; Chowdary, D. Deepak; Bharathi, M. Aruna; Patra, Stutee

2017-07-01

This paper furnish the new Metaheuristic algorithm called Cuckoo Search Algorithm (CSA) for solving optimal power flow (OPF) problem with minimization of real power generation cost. The CSA is found to be the most efficient algorithm for solving single objective optimal power flow problems. The CSA performance is tested on IEEE 57 bus test system with real power generation cost minimization as objective function. Static VAR Compensator (SVC) is one of the best shunt connected device in the Flexible Alternating Current Transmission System (FACTS) family. It has capable of controlling the voltage magnitudes of buses by injecting the reactive power to system. In this paper SVC is integrated in CSA based Optimal Power Flow to optimize the real power generation cost. SVC is used to improve the voltage profile of the system. CSA gives better results as compared to genetic algorithm (GA) in both without and with SVC conditions.

A new approach to flow-batch titration. A monosegmented flow titrator with coulometric reagent generation and potentiometric or biamperometric detection.

PubMed

de Aquino, Emerson Vidal; Rohwedder, Jarbas José Rodrigues; Pasquini, Celio

2006-11-01

Monosegmented flow analysis (MSFA) has been used as a flow-batch system to produce a simple, robust, and mechanized titrator that enables true titrations to be performed without the use of standards. This paper also introduces the use of coulometry with monosegmented titration by proposing a versatile flow cell. Coulometric generation of the titrand is attractive for titrations performed in monosegmented systems, because the reagent can be added without increasing the volume of sample injected. Also, biamperomeric and potentiometric detection of titration end-points can increase the versatility of the monosegmented titrator. The cell integrates coulometric generation of the titrand with detection of end-point by potentiometry or biamperometry. The resulting titrator is a flow-batch system in which the liquid monosegment, constrained by the interfaces of the gaseous carrier stream, plays the role of a sample of known volume to be titrated. The system has been used for determination of ascorbic acid, by coulometric generation of I2 with biamperometric detection, and for determination of Fe(II), by coulometric generation of Ce(IV) with potentiometric detection of the end-point, both in feed supplements.

Effects of Injection Scheme on Rotating Detonation Engine Operation

NASA Astrophysics Data System (ADS)

Chacon, Fabian; Duvall, James; Gamba, Mirko

2017-11-01

In this work, we experimentally investigate the operation and performance characteristics of a rotating detonation engine (RDE) operated with different fuel injection schemes and operating conditions. In particular, we investigate the detonation and operation characteristics produced with an axial flow injector configuration and semi-impinging injector configurations. These are compared to the characteristics produced with a canonical radial injection system (AFRL injector). Each type produces a different flowfield and mixture distribution, leading to a different detonation initiation, injector dynamic response, and combustor pressure rise. By using a combination of diagnostics, we quantify the pressure loses and gains in the system, the ability to maintain detonation over a range of operating points, and the coupling between the detonation and the air/fuel feed lines. We particularly focus on how this coupling affects both the stability and the performance of the detonation wave. This work is supported by the DOE/UTSR program under project DE-FE0025315.

Fuel injection device and method

DOEpatents

Carlson, L.W.

1983-12-21

A fuel injection system and method provide for shaping a combustion plume within a combustion chamber to effectively recirculate hot combustion gases for stable combustion conditions while providing symmetrical combustion conditions. Char and molten slag are passed to the outer boundary layer to complete combustion of char while permitting initial substoichiometric combustion in a reductive atmosphere for reducing discharge of nitrogen oxides. Shaping of the plume is accomplished by an axially adjustable pintle which permits apportionment of driving pressure between elements which contribute tangential and those which contribute radial directional components to oxidant flow entering the combustion chamber.

Nox reduction system utilizing pulsed hydrocarbon injection

DOEpatents

Brusasco, Raymond M.; Penetrante, Bernardino M.; Vogtlin, George E.; Merritt, Bernard T.

2001-01-01

Hydrocarbon co-reductants, such as diesel fuel, are added by pulsed injection to internal combustion engine exhaust to reduce exhaust NO.sub.x to N.sub.2 in the presence of a catalyst. Exhaust NO.sub.x reduction of at least 50% in the emissions is achieved with the addition of less than 5% fuel as a source of the hydrocarbon co-reductants. By means of pulsing the hydrocarbon flow, the amount of pulsed hydrocarbon vapor (itself a pollutant) can be minimized relative to the amount of NO.sub.x species removed.

Fuel injection device and method

DOEpatents

Carlson, Larry W.

1986-01-01

A fuel injection system and method provide for shaping a combustion plume within a combustion chamber to effectively recirculate hot combustion gases for stable combustion conditions while providing symmetrical combustion conditions. Char and molten slag are passed to the outer boundary layer to complete combustion of char while permitting initial substoichiometric combustion in a reductive atmosphere for reducing discharge of nitrogen oxides. Shaping of the plume is accomplished by an axially adjustable pintle which permits apportionment of driving pressure between elements which contribute tangential and those which contribute radial directional components to oxidant flow entering the combustion chamber.

Fuel injection device and method

DOEpatents

Carlson, Larry W.

1986-02-04

A fuel injection system and method provide for shaping a combustion plume within a combustion chamber to effectively recirculate hot combustion gases for stable combustion conditions while providing symmetrical combustion conditions. Char and molten slag are passed to the outer boundary layer to complete combustion of char while permitting initial substoichiometric combustion in a reductive atmosphere for reducing discharge of nitrogen oxides. Shaping of the plume is accomplished by an axially adjustable pintle which permits apportionment of driving pressure between elements which contribute tangential and those which contribute radial directional components to oxidant flow entering the combustion chamber.

Downstream influence of swept slot injection in hypersonic turbulent flow

NASA Technical Reports Server (NTRS)

Hefner, J. N.; Cary, A. M., Jr.; Bushnell, D. B.

1977-01-01

Results of an experimental and numerical investigation of tangential swept slot injection into a thick turbulent boundary layer at Mach 6 are presented. Film cooling effectiveness, skin friction, and flow structure downstream of the swept slot injection were investigated. The data were compared with that for unswept slots, and it was found that cooling effectiveness and skin friction reductions are not significantly affected by sweeping the slot.

Stopped-in-loop flow analysis of trace vanadium in water.

PubMed

Teshima, Norio; Ohno, Shinsuke; Sakai, Tadao

2007-01-01

The new concept of stopped-in-loop flow analysis (SIL-FA) is proposed, and an SIL-FA method for the catalytic determination of vanadium is demonstrated. In an SIL format, a sample solution merges with reagent(s), and the well-mixed solution is loaded into a loop. The solution in the loop is separated by a six-way switching valve from the main stream. While the reaction proceeds in the stationary loop, the SIL-FA system does not need to establish a baseline continuously. This leads to a reduction in reagent consumption and waste generation compared with traditional flow injection analysis.

Reducing or stopping the uncontrolled flow of fluid such as oil from a well

DOEpatents

Hermes, Robert E

2014-02-18

The uncontrolled flow of fluid from an oil or gas well may be reduced or stopped by injecting a composition including 2-cyanoacrylate ester monomer into the fluid stream. Injection of the monomer results in a rapid, perhaps instantaneous, polymerization of the monomer within the flow stream of the fluid. This polymerization results in formation of a solid plug that reduces or stops the flow of additional fluid from the well.

Power flow control using quadrature boosters

NASA Astrophysics Data System (ADS)

Sadanandan, Sandeep N.

A power system that can be controlled within security constraints would be an advantage to power planners and real-time operators. Controlling flows can lessen reliability issues such as thermal limit violations, power stability problems, and/or voltage stability conditions. Control of flows can also mitigate market issues by reducing congestion on some lines and rerouting power to less loaded lines or onto preferable paths. In the traditional control of power flows, phase shifters are often used. More advanced methods include using Flexible AC Transmission System (FACTS) Controllers. Some examples include Thyristor Controlled Series Capacitors, Synchronous Series Static Compensators, and Unified Power Flow Controllers. Quadrature Boosters (QBs) have similar structures to phase-shifters, but allow for higher voltage magnitude during real power flow control. In comparison with other FACTS controllers QBs are not as complex and not as expensive. The present study proposes to use QBs to control power flows on a power system. With the inclusion of QBs, real power flows can be controlled to desired scheduled values. In this thesis, the linearized power flow equations used for power flow analysis were modified for the control problem. This included modifying the Jacobian matrix, the power error vector, and calculating the voltage injected by the quadrature booster for the scheduled real power flow. Two scenarios were examined using the proposed power flow control method. First, the power flow in a line in a 5-bus system was modified with a QB using the method developed in this thesis. Simulation was carried out using Matlab. Second, the method was applied to a 30-bus system and then to a 118-bus system using several QBs. In all the cases, the calculated values of the QB voltages led to desired power flows in the designated line.

Study of local currents in low dimension materials using complex injecting potentials

NASA Astrophysics Data System (ADS)

He, Shenglai; Covington, Cody; Varga, Kálmán

2018-04-01

A complex potential is constructed to inject electrons into the conduction band, mimicking electron currents in nanoscale systems. The injected electrons are time propagated until a steady state is reached. The local current density can then be calculated to show the path of the conducting electrons on an atomistic level. The method allows for the calculation of the current density vectors within the medium as a function of energy of the conducting electron. Using this method, we investigate the electron pathway of graphene nanoribbons in various structures, molecular junctions, and black phosphorus nanoribbons. By analyzing the current flow through the structures, we find strong dependence on the structural geometry and the energy of the injected electrons. This method may be of general use in the study of nano-electronic materials and interfaces.

Studies of the effects of curvature on dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, James D.; Srinivasan, Ram; Reynolds, Robert S.; White, Craig D.

1992-01-01

An analytical program was conducted using both three-dimensional numerical and empirical models to investigate the effects of transition liner curvature on the mixing of jets injected into a confined crossflow. The numerical code is of the TEACH type with hybrid numerics; it uses the power-law and SIMPLER algorithms, an orthogonal curvilinear coordinate system, and an algebraic Reynolds stress turbulence model. From the results of the numerical calculations, an existing empirical model for the temperature field downstream of single and multiple rows of jets injected into a straight rectangular duct was extended to model the effects of curvature. Temperature distributions, calculated with both the numerical and empirical models, are presented to show the effects of radius of curvature and inner and outer wall injection for single and opposed rows of cool dilution jets injected into a hot mainstream flow.